JP4245000B2 - Electric power steering device - Google Patents

Description

  The present invention relates to an electric power steering device that applies assist force by a motor to a steering system of an automobile or a vehicle, and more specifically, electric power provided with a booster circuit that can adjust a current supplied from a vehicle-mounted battery to a motor. The present invention relates to a steering device.

  Conventionally, an electric power steering control device that assists the operation of a steering wheel by using the rotational force of a motor has been used. In such an electric power steering apparatus, a steering assist force according to the steering torque when the driver performs steering by rotating the steering wheel is applied from the motor to the steering mechanism.

By the way, the electric power steering apparatus as described above is a system that requires a large current in order to obtain a large torque.
Conventionally, a vehicle-mounted battery (DC12V) is applied directly, and a motor with a DC12V specification is used. In order to supply a large current to the motor, the motor is enlarged and the wiring capacity is increased. (Thickening) cannot be avoided.

In order to solve this problem, an electric power steering device (Patent Document 1) that can adjust the current supplied from the on-vehicle battery has been proposed.
In this electric power steering apparatus, a booster circuit 300 and a booster circuit controller 301 as shown in FIG. 51 are provided in a circuit for supplying a current to the motor.
The booster circuit 300 is provided between an application point P1 of a battery voltage VPIG (DC12V) from an in-vehicle battery and a voltage application point P2 to the motor. The booster circuit 300 includes capacitors C1 and C2, a coil L, a diode D, and a switching transistor Q1.

  The booster circuit control device 301 outputs a duty ratio drive signal for boosting to the transistor Q1 of the booster circuit 300, and duty-controls the transistor Q1 by this duty ratio drive signal. Due to this duty control, the transistor Q1 performs a switching operation as shown in FIG. 52. As a result, the accumulation and release of energy are repeated in the coil L, and a high voltage at the time of discharge appears on the cathode side of the diode D. As shown in FIG. 52, in this specification, Tα represents an on time, T represents a pulse period, and α represents a duty ratio (on duty). When the transistor Q1 is turned on, a current flows through the coil L, and when the transistor Q1 is turned off, the current flowing through the coil L is interrupted.

  When the current flowing through the coil L is interrupted, a high voltage is generated on the cathode side of the diode D so as to prevent a change in magnetic flux due to the interruption of the current. By repeating this, a high voltage is repeatedly generated on the cathode side of the diode D, smoothed (charged) by the capacitor C2, and generated at the point P2 as the output voltage VBPIG.

At this time, the voltage boosted by the booster circuit 300 is related to the duty ratio of the duty ratio drive signal output from the booster circuit control device 301. If the duty ratio is large, the output voltage VBPIG is high, and if the duty ratio is small, the output voltage VBPIG is low.
JP-A-8-127350

  However, since the conventional booster circuit 300 uses the diode D as described above, when the motor enters the regenerative state, a current flows from the voltage application point P2 side to the battery B due to the diode D. Output voltage VBPIG rises. There is a concern that the booster circuit 300 may be damaged due to the increase in voltage. For example, in the example of FIG. 51, the capacitor C2 and the diode D constituting the booster circuit 300 may be destroyed.

  An object of the present invention is to provide an electric power steering device in which the booster circuit is not destroyed even when the motor is in a regenerative state, and power running and assist control during assist control of the electric power steering device. An object of the present invention is to provide an electric power steering apparatus that realizes booster circuit control capable of controlling heat generation (switching loss) of a switching element and an increase in output voltage during regeneration.

In order to solve the above-mentioned problems, the invention according to claim 1 determines a motor control signal based on at least a steering torque of a steering wheel, and outputs a control signal generating means for outputting the signal, and the motor control signal. Rutotomoni a motor driving means for driving the electric motor, battery and provided with a booster circuit to the current supply circuit between said motor drive means, said boosting circuit, one end is connected to the battery the battery voltage is applied on the basis of A step-up coil, a first switching element that grounds or opens the step-up coil, a second switching element that is connected to the other end of the step-up coil and is turned on and off, and an output side of the second switching element And a capacitor for smoothing a boosted voltage (hereinafter referred to as an output voltage) by the boosting coil, the target output voltage and the output Based on the deviation from the pressure, among the first and second switching elements, at the time of power running, at least the first switching element is turned on / off to boost the supply voltage of the motor, and at the time of regeneration, at least the second switching element is turned on / off. comparison in the electric power steering apparatus Ru and a boosting circuit control means for performing boost control to a state parameter detecting means for detecting a state parameter of the booster circuit, and a decision value and a state parameter the condition parameter detecting means detects And determining means for determining whether or not the booster circuit is normal. The booster circuit control means stops boosting control of the booster circuit according to the result determined by the determining means, and the determining means When a failure is determined, the first switching element is always turned off, and the second switching element It is an gist an electric power steering apparatus, characterized by always-on control.

According to a second aspect of the present invention, there is provided a control signal generating means for determining an electric motor control signal based on at least a steering torque of the steering wheel and outputting the signal, and an electric motor driving means for driving the electric motor based on the electric motor control signal. comprising Rutotomoni, battery and providing a booster circuit to the current supply circuit between the electric motor drive unit, the booster circuit includes a booster coil whose one end connected to the battery voltage in the battery is applied, the earth the boosting coil A first switching element that is connected or disconnected, a second switching element that is connected to the other end of the boosting coil and is turned on / off, and is connected to an output side of the second switching element. Hereinafter referred to as an output voltage), and based on the deviation between the target output voltage and the output voltage, Of the two switching elements, the power running, while boosting the supply voltage of at least the first by turning on and off the switching elements motor during regeneration and a step-up circuit control means for performing boost control to turn on and off at least a second switching element In the electric power steering apparatus, the booster circuit control means includes target output voltage setting means for setting a target output voltage of the booster circuit, and control calculation means for performing at least P control calculation based on a deviation between the target output voltage and the output voltage. And PWM calculation means for calculating the duty ratio based on the calculation value of the control calculation means, and calculating the duty ratio. The first and second switching elements are controlled based on the duty ratio calculated by the PWM calculation means. is intended to on-off control, the target output voltage setting means, vehicle or electric The operation status parameter indicating the operation status of the machine is input, the target output voltage is made variable according to the operation status parameter, connected to the battery voltage supply unit of the booster circuit, and on / off controlled by the booster circuit control means A first opening / closing means; a circuit connected via a first resistor to a connection point between the drain of the first switching element and the battery voltage supply unit and applying an ignition voltage when the ignition switch is turned on; The boosting circuit control means includes a first element that controls at least the first switching element among the first switching element and the second switching element before the first opening / closing means is turned on when the ignition switch is turned on. And a drain for detecting a drain voltage of the first switching element or the second switching element. And a first failure determination means for comparing the drain voltage with a first failure determination value to determine a failure of the booster circuit .

According to a third aspect of the present invention, there is provided a control signal generating means for determining an electric motor control signal based on at least a steering torque of the steering wheel and outputting the signal, and an electric motor driving means for driving the electric motor based on the electric motor control signal. comprising Rutotomoni, battery and providing a booster circuit to the current supply circuit between the electric motor drive unit, the booster circuit includes a booster coil whose one end connected to the battery voltage in the battery is applied, the earth the boosting coil A first switching element that is connected or disconnected, a second switching element that is connected to the other end of the boosting coil and is turned on / off, and is connected to an output side of the second switching element. Hereinafter referred to as an output voltage), and based on the deviation between the target output voltage and the output voltage, Of the two switching elements, the power running, while boosting the supply voltage of at least the first by turning on and off the switching elements motor during regeneration and a step-up circuit control means for performing boost control to turn on and off at least a second switching element In the electric power steering apparatus, the booster circuit control means includes target output voltage setting means for setting a target output voltage of the booster circuit, and control calculation means for performing at least P control calculation based on a deviation between the target output voltage and the output voltage. And PWM calculation means for calculating the duty ratio based on the calculation value of the control calculation means, and calculating the duty ratio. The first and second switching elements are controlled based on the duty ratio calculated by the PWM calculation means. On-off control is performed, and the booster circuit control means has a predetermined duty. The first switching means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means, and the drain of the first switching element; A circuit connected to a connection point between the battery voltage supply units via a first resistor and applying an ignition voltage when the ignition switch is turned on, and the booster circuit control means includes a circuit when the ignition switch is turned on. First element control means for controlling on or off of at least the first switching element among the first switching element and the second switching element, and the first switching element or the second switching element before the first opening / closing means is on-controlled. Drain voltage detecting means for detecting the drain voltage of the first and second drain voltages and the first failure judgment And a first failure determination means for comparing the constant value and determining a failure of the booster circuit .

According to a fourth aspect of the present invention, there is provided a control signal generating means for determining an electric motor control signal based on at least a steering torque of the steering wheel and outputting the signal, and an electric motor driving means for driving the electric motor based on the electric motor control signal. And a step-up circuit is provided in a current supply circuit between the battery and the motor driving means, and the step-up circuit is connected to the battery at one end side, and the step-up coil to which the battery voltage is applied and the step-up coil are grounded. Alternatively, the first switching element to be opened, the second switching element connected to the other end side of the boosting coil and connected to the output side of the second switching element, connected to the output side of the second switching element, and the boosted voltage (hereinafter referred to as the boosting voltage). And a capacitor for smoothing the output voltage), and based on a deviation between the target output voltage and the output voltage, the first and Among the two switching elements, there is provided boosting circuit control means for boosting the supply voltage of the motor by turning on / off at least the first switching element during power running and executing boosting control for turning on / off at least the second switching element during regeneration. In the electric power steering apparatus, the state parameter detecting means for detecting the state parameter of the booster circuit, and the determining means for comparing the state parameter detected by the state parameter detecting means and the determination value to determine whether or not the booster circuit is normal And the booster circuit control means stops boosting control of the booster circuit according to the result determined by the determining means, is connected to the battery voltage supply unit of the booster circuit, and is connected to the booster circuit control means. First opening / closing means controlled on and off, and the drain of the first switching element A circuit connected to a connection point between the battery voltage supply units via a first resistor and applying an ignition voltage when the ignition switch is turned on, and the booster circuit control means includes a circuit when the ignition switch is turned on. First element control means for controlling on or off of at least the first switching element among the first switching element and the second switching element, and the first switching element or the second switching element before the first opening / closing means is on-controlled. The drain voltage detecting means for detecting the drain voltage of the first step and the first failure determining means for comparing the drain voltage and the first failure determination value to determine the failure of the booster circuit .

The invention of claim 5 is off Oite to claim 4, the first switching means is turned on and off controlled by the step-up circuit control means is connected to the battery voltage supply unit of the booster circuit, the electric power of the electric motor A second opening / closing means is provided, and when the determination means makes a failure determination, the booster circuit control means controls the first opening / closing means and the second opening / closing means to be turned off .

The invention of claim 6, Oite to claim 4, when said determination means determines failure, the first switching element always off control, characterized by always-on control of the second switching element.

The invention according to claim 7, or any one of claims 2 to 6 , further comprising second opening / closing means for turning on / off electric power of the motor, and when the first failure determination means determines failure, the booster circuit control means Is characterized in that the first opening / closing means and the second opening / closing means are turned off.

According to an eighth aspect of the present invention, in any one of the second to sixth aspects, the apparatus further comprises second opening / closing means for turning on / off the electric power of the electric motor, and when the first failure determination means determines a failure, the booster circuit is controlled. The means is characterized in that both the first opening / closing means and the second opening / closing means are on-controlled, the first switching element is always off-controlled, and the second switching element is always on-controlled.

According to a ninth aspect of the present invention, there is provided a control signal generating means for determining an electric motor control signal based on at least a steering torque of the steering wheel and outputting the signal, and an electric motor driving means for driving the electric motor based on the electric motor control signal. And a step-up circuit is provided in a current supply circuit between the battery and the motor driving means, and the step-up circuit is connected to the battery at one end side, and the step-up coil to which the battery voltage is applied and the step-up coil are grounded. Alternatively, the first switching element to be opened, the second switching element connected to the other end side of the boosting coil and connected to the output side of the second switching element, connected to the output side of the second switching element, and the boosted voltage (hereinafter referred to as the boosting voltage). And a capacitor for smoothing the output voltage), and based on a deviation between the target output voltage and the output voltage, the first and Among the two switching elements, there is provided boosting circuit control means for boosting the supply voltage of the motor by turning on / off at least the first switching element during power running and executing boosting control for turning on / off at least the second switching element during regeneration. In the electric power steering apparatus, the booster circuit control means includes target output voltage setting means for setting a target output voltage of the booster circuit, and control arithmetic means for performing at least P control calculation based on a deviation between the target output voltage and the output voltage. And PWM calculation means for calculating a duty ratio by performing PWM calculation based on the calculation value of the control calculation means, and turning on and off the first and second switching elements based on the duty ratio calculated by the PWM calculation means And the target output voltage setting means is a vehicle or a power supply. Enter the driving condition parameter indicating the operating status of the machine, and the target output voltage variable in accordance with the driving condition parameter, on-off controlled by the step-up circuit control means is connected to the battery voltage supply unit of the booster circuit A first opening / closing means; and a circuit connected to the drain of the second switching element via a second resistor for applying an ignition voltage when the ignition switch is turned on. The boosting circuit control means includes an ignition switch At the time of ON, before the first opening / closing means is ON-controlled, the second element control means for simultaneously controlling ON / OFF for both the first switching element and the second switching element, or simultaneously controlling OFF / ON respectively. And at least a first switching element among the first switching element and the second switching element A drain voltage detecting means for detecting the drain voltage of the first booster circuit; and a second failure determining means for comparing the drain voltage with a second failure determination value to determine a failure of the booster circuit.

According to a tenth aspect of the present invention, there is provided a control signal generating means for determining an electric motor control signal based on at least a steering torque of the steering wheel and outputting the signal, and an electric motor driving means for driving the electric motor based on the electric motor control signal. And a step-up circuit is provided in a current supply circuit between the battery and the motor driving means, and the step-up circuit is connected to the battery at one end side, and the step-up coil to which the battery voltage is applied and the step-up coil are grounded. Alternatively, the first switching element to be opened, the second switching element connected to the other end side of the boosting coil and connected to the output side of the second switching element, connected to the output side of the second switching element, and the boosted voltage (hereinafter referred to as the boosting voltage). And a capacitor for smoothing the output voltage), and based on the deviation between the target output voltage and the output voltage, Of the second switching elements, boosting circuit control means for boosting the supply voltage of the motor by turning on and off at least the first switching element during power running and performing boost control for turning on and off at least the second switching element during regeneration. In the electric power steering apparatus provided, the booster circuit control means includes target output voltage setting means for setting a target output voltage of the booster circuit, and control calculation means for performing at least P control calculation based on a deviation between the target output voltage and the output voltage. And PWM calculation means for calculating the duty ratio based on the calculation value of the control calculation means, and calculating the duty ratio. The first and second switching elements are controlled based on the duty ratio calculated by the PWM calculation means. On-off control is performed, and the booster circuit control means has a predetermined duty cycle. The first switching means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means, and the drain of the second switching element so as not to perform PWM control beyond the ratio And a circuit for applying an ignition voltage when the ignition switch is turned on, the booster circuit control means before the first opening / closing means is turned on when the ignition switch is turned on. And a second element control means for simultaneously controlling on or off for each of the first switching element and the second switching element, or for simultaneously controlling off and on respectively, and the first switching element and the second switching element. A drain voltage detecting means for detecting at least the drain voltage of the first switching element And a second failure determination means for comparing the drain voltage with a second failure determination value to determine a failure of the booster circuit .

According to an eleventh aspect of the present invention, there is provided a control signal generating means for determining an electric motor control signal based on at least a steering torque of the steering wheel and outputting the signal, and an electric motor driving means for driving the electric motor based on the electric motor control signal. And a step-up circuit is provided in a current supply circuit between the battery and the motor driving means, and the step-up circuit is connected to the battery at one end side, and the step-up coil to which the battery voltage is applied and the step-up coil are grounded. Alternatively, the first switching element to be opened, the second switching element connected to the other end side of the boosting coil and connected to the output side of the second switching element, connected to the output side of the second switching element, and the boosted voltage (hereinafter referred to as the boosting voltage). And a capacitor for smoothing the output voltage), and based on the deviation between the target output voltage and the output voltage, Of the second switching elements, boosting circuit control means for boosting the supply voltage of the motor by turning on and off at least the first switching element during power running and performing boost control for turning on and off at least the second switching element during regeneration. And determining whether or not the booster circuit is normal by comparing the state parameter detected by the state parameter detector with the determination value. And the booster circuit control means stops boosting control of the booster circuit according to the result determined by the determining means, is connected to the battery voltage supply unit of the booster circuit, and is boosted circuit control means The first opening / closing means controlled to be turned on and off by the second switching element and the drain of the second switching element And a circuit for applying an ignition voltage when the ignition switch is turned on, the booster circuit control means before the first opening / closing means is turned on when the ignition switch is turned on. And a second element control means for simultaneously controlling on or off for each of the first switching element and the second switching element, or for simultaneously controlling off and on respectively, and the first switching element and the second switching element. Among them, there is provided drain voltage detection means for detecting at least the drain voltage of the first switching element, and second failure determination means for comparing the drain voltage with a second failure determination value to determine a failure of the booster circuit. It is characterized by.
According to a twelfth aspect of the present invention, in the eleventh aspect, a first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means, and a second switch for turning on / off the power of the motor Opening / closing means is provided, and when the determination means makes a failure determination, the booster circuit control means controls the first opening / closing means and the second opening / closing means to be off.
A thirteenth aspect of the invention is characterized in that, in the eleventh aspect, when the determination means makes a failure determination, the first switching element is always off-controlled and the second switching element is always on-controlled.
According to a fourteenth aspect of the present invention, in any one of the second to eighth aspects, the first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means. A circuit connected to the drain of the second switching element via a second resistor and applying an ignition voltage when the ignition switch is turned on, and the booster circuit control means includes a first circuit when the ignition switch is turned on. Before the ON / OFF control of the opening / closing means, both the first switching element and the second switching element are simultaneously ON controlled or OFF controlled, or the second element control means for simultaneously controlling OFF and ON respectively, and the first switching Drain for detecting a drain voltage of at least the first switching element among the elements and the second switching element Compared with pressure detecting means, the drain voltage and the second failure determination value, characterized in that a second failure determining means for failure judgment of the step-up circuit.
According to a fifteenth aspect of the present invention, in any one of the ninth to fourteenth aspects, the apparatus further comprises second opening / closing means for turning on / off electric power of the electric motor, and when the second failure determination means determines a failure, the booster circuit control means Is characterized in that the first opening / closing means and the second opening / closing means are turned off.
According to a sixteenth aspect of the present invention, in any one of the ninth to fourteenth aspects, the apparatus further comprises second opening / closing means for turning on / off the electric power of the electric motor, and when the second failure determination means determines a failure, the booster circuit control means Is characterized in that both the first opening / closing means and the second opening / closing means are on-controlled, the first switching element is always off-controlled, and the second switching element is always on-controlled.

As described above in detail, according to the invention described in claims 1 to 16 , an electric power steering device is provided in which the booster circuit is not destroyed even when the motor is in a regenerative state. be able to.

According to the second and ninth aspects of the invention, since the target output voltage is made variable according to the driving condition parameter indicating the driving condition of the vehicle or the motor, the first and second switching elements are set according to the driving condition. It can be controlled on and off.

According to the third and tenth aspects of the present invention, since the duty limit is provided, the booster circuit can be prevented from being damaged both during power running and during regeneration.
According to the invention described in claims 1, 4 to 6, 11 to 13 , when the booster circuit is out of order, the booster control of the booster circuit can be stopped, and the booster circuit when the booster circuit is abnormal Can be prevented.

According to the fifth and twelfth aspects of the present invention, when the booster circuit is out of order, it is possible to shift to manual steering. In addition, even during regeneration, the regenerative current does not flow to the booster circuit, and the circuit elements constituting the booster circuit can be prevented from being destroyed.

According to the invention described in claims 6 and 13 , when the booster circuit is out of order, the assist control can be continuously executed with the battery voltage, and at the time of regeneration, the regenerative current can be absorbed by the battery. .

According to the invention described in claims 2 to 8 and 14 , the failure determination of the booster circuit can be performed at the stage of the initial check after turning on the ignition switch.
According to the seventh aspect of the present invention, when the booster circuit has failed at the stage of the initial check after turning on the ignition switch, fail-safe can be applied.

  According to the eighth aspect of the present invention, when the booster circuit fails at the stage of the initial check after turning on the ignition switch, the assist control cannot be performed with the voltage boosted by the booster circuit. While being able to execute with voltage, at the time of regeneration, the regenerative current can be absorbed by the battery.

According to the ninth to sixteenth aspects of the present invention, the failure determination of the booster circuit can be performed at the stage of the initial check after turning on the ignition switch.
According to the fifteenth aspect of the present invention, when the booster circuit has failed at the stage of the initial check after turning on the ignition switch, fail safe can be applied.

According to the sixteenth aspect of the present invention, when the booster circuit fails at the stage of the initial check after turning on the ignition switch, the assist control cannot be performed with the voltage boosted by the booster circuit. While being able to execute with voltage, at the time of regeneration, the regenerative current can be absorbed by the battery.

1. First embodiment (reference embodiment)
(Constitution)
In the first to tenth embodiments, an electric power steering apparatus embodied as a reference embodiment will be described with reference to FIGS.

FIG. 1 shows an outline of a control device of an electric power steering device.
A torsion bar 3 is provided on a steering shaft 2 connected to the steering wheel 1. A torque sensor 4 is attached to the torsion bar 3. When the steering shaft 2 rotates and a force is applied to the torsion bar 3, the torsion bar 3 is twisted according to the applied force, and the torque sensor 4 detects the twist, that is, the steering torque τ applied to the steering wheel 1. Yes.

The torque sensor 4 constitutes a steering torque detection means.
A reduction gear 5 is fixed to the steering shaft 2. The speed reducer 5 is meshed with a gear 7 attached to a rotating shaft of an electric motor (hereinafter referred to as a motor) 6 as an electric motor. The motor 6 is a brushless motor constituted by a three-phase synchronous permanent magnet motor.

  The motor 6 is assembled with a rotation angle sensor 30 constituted by an encoder for detecting the rotation angle of the motor 6 (see FIG. 2). The rotation angle sensor 30 outputs a two-phase pulse train signal having a phase different by π / 2 according to the rotation of the rotor of the motor 6 and a zero-phase pulse train signal representing the reference rotational position.

  Further, a pinion shaft 8 is fixed to the speed reducer 5. A pinion 9 is fixed to the tip of the pinion shaft 8, and the pinion 9 meshes with the rack 10. A tie rod 12 is fixed to both ends of the rack 10, and a knuckle 13 is rotatably connected to the tip of the tie rod 12. A front wheel 14 as a tire is fixed to the knuckle 13. One end of the knuckle 13 is rotatably connected to the cross member 15.

  Therefore, when the motor 6 rotates, the rotation speed is reduced by the speed reducer 5 and transmitted to the pinion shaft 8 and is transmitted to the rack 10 via the pinion and rack mechanism 11. The rack 10 can change the traveling direction of the vehicle by changing the direction of the front wheel 14 provided on the knuckle 13 via the tie rod 12.

A vehicle speed sensor 16 is provided on the front wheel 14.
Next, an electrical configuration of the electric power steering apparatus 20 will be shown.
The torque sensor 4 outputs a voltage corresponding to the steering torque τ of the steering wheel 1. The vehicle speed sensor 16 outputs the vehicle speed at that time as a pulse signal having a period relative to the rotational speed of the front wheels 14.

  The electric power steering control device (hereinafter referred to as a control device) 20 includes a central processing unit (CPU) 21, a read only memory (ROM) 22, and a read and write only memory (RAM) 23 for temporarily storing data. The ROM 22 stores a control program for causing the CPU 21 to perform arithmetic processing. The RAM 23 temporarily stores calculation processing results and the like when the CPU 21 performs calculation processing.

  The ROM 22 stores a basic assist map (not shown). The basic assist map is for obtaining a basic assist current corresponding to the steering torque τ (rotation torque) and corresponding to the vehicle speed, and stores the basic assist current for the steering torque τ.

Since the function of the control device 20 for driving and controlling the three-phase synchronous permanent magnet motor is a known configuration, it will be briefly described.
The control device 20 corresponds to control signal generating means.

  FIG. 3 is a control block diagram showing functions executed by programs in the CPU 21. Each unit illustrated in the control block diagram does not indicate independent hardware, but indicates a function executed by the CPU 21.

  The control device 20 includes a basic assist force calculation unit 51, a return force calculation unit 52, and an addition unit 53 for calculating the command torque τ *. The basic assist force calculation unit 51 receives the steering torque τ from the torque sensor 4 and the vehicle speed V detected by the vehicle speed sensor 16, and increases as the steering torque τ increases and decreases as the vehicle speed V increases. Calculate

  The return force calculation unit 52 inputs the electrical angle θ (corresponding to the rotation angle) and the angular velocity ω of the rotor of the motor 6 together with the vehicle speed V, and based on these input values, the return force to the basic position of the steering shaft 2 and A return torque corresponding to the resistance force against the rotation of the steering shaft 2 is calculated. The adder 53 calculates the command torque τ * by adding the assist torque and the return torque, and outputs the command torque τ * to the command current setting unit 54.

  The command current setting unit 54 calculates the two-phase command currents Id * and Iq * based on the command torque τ *. The command currents Id * and Iq * correspond to the d-axis in the same direction as the permanent magnet and the q-axis orthogonal thereto in the rotating coordinate system synchronized with the rotating magnetic flux generated by the permanent magnet on the rotor of the motor 6. These command currents Id * and Iq * are referred to as d-axis and q-axis command currents, respectively.

  The d-axis command current Id * and the q-axis command current Iq * are supplied to the subtracters 55 and 56. The subtractors 55 and 56 calculate difference values ΔId and ΔIq between the d-axis command current Id * and the q-axis command current Iq * and the d-axis and q-axis detection currents Id and Iq, respectively, and perform PI control on the results. Part (proportional integral control part) 57,58. The q-axis command current Iq * corresponds to a motor control signal.

  The PI control units 57 and 58 are configured so that the d-axis and q-axis command currents Id and Iq follow the d-axis command current Id * and q-axis command current Iq * based on the difference values ΔId and ΔIq. The voltages Vd * and Vq * are calculated respectively.

  The d-axis and q-axis command voltages Vd * and Vq * are corrected to d-axis and q-axis correction command voltages Vd ** and Vq ** by the non-interference control correction value calculation unit 63 and the subtractors 59 and 60, respectively. The phase / three-phase coordinate conversion unit 61 is supplied.

  The non-interference control correction value calculation unit 63 performs non-interference for the d-axis and q-axis command voltages Vd * and Vq * based on the d-axis and q-axis detection currents Id and Iq and the angular velocity ω of the rotor of the motor 6. The control correction value ω · La · Iq, −ω · (φa + La · Id) is calculated. The inductance La and the magnetic flux φa are predetermined constants.

  The subtractors 59 and 60 calculate the d-axis and q-axis correction command voltages Vd ** and Vq ** by subtracting the non-interference control correction values from the d-axis and q-axis command voltages Vd * and Vq *, respectively. And output to the 2-phase / 3-phase coordinate converter 61. The two-phase / three-phase coordinate conversion unit 61 converts the d-axis and q-axis correction command voltages Vd ** and Vq ** into the three-phase command voltages Vu *, Vv *, and Vw *, and the converted three-phase command. The voltages Vu *, Vv *, and Vw * are output to the PWM control unit 62.

  The PWM control unit 62 converts the PWM control signals UU, VU, WU (including the PWM wave signal and the signal indicating the rotation direction of the motor 6) corresponding to the three-phase command voltages Vu *, Vv *, Vw *, It outputs to the motor drive device 35 which is an inverter circuit.

  As shown in FIG. 2, the motor drive device 35 is configured by connecting a series circuit of FETs (Field-Effect Transistors) 81U and 82U, a series circuit of FETs 81V and 82V, and a series circuit of FETs 81W and 82W in parallel. ing. A voltage boosted from the voltage of the battery mounted on the vehicle is applied to each series circuit. The connection point 83U between the FETs 81U and 82U is connected to the U-phase winding of the motor M, the connection point 83V between the FETs 81V and 82V is connected to the V-phase winding of the motor 6, and the connection point 83W between the FETs 81W and 82W. Is connected to the W-phase winding of the motor 6.

  For the FETs 81U, 82U, FETs 81V, 82V and FETs 81W, 82W, PWM control signals UU, VU, WU from the PWM control unit 62 (in each phase PWM control signals, a PWM wave signal and a signal indicating the rotation direction of the motor 6). Is included).

The motor driving device 35 generates three-phase excitation currents corresponding to the PWM control signals UU, VU, WU and supplies them to the motor 6 via the three-phase excitation current paths.
The motor driving device 35 constitutes an electric motor driving means.

  Current sensors 71 and 72 are provided in two of the three-phase excitation current paths, and each of the current sensors 71 and 72 is an excitation current of two of the three-phase excitation currents Iu, Iv, and Iw for the motor 6. Iu and Iv are detected and output to the three-phase / two-phase coordinate converter 73 shown in FIG.

  The three-phase / two-phase coordinate conversion unit 73 receives the excitation current Iw calculated by the calculator 74 based on the detected excitation currents Iu and Iv. The three-phase / two-phase coordinate conversion unit 73 converts these three-phase detection excitation currents Iu, Iv, Iw into two-phase d-axis and q-axis detection currents Id, Iq, and subtracters 55, 56, non-interference control. The value is input to the correction value calculation unit 63.

  The two-phase pulse train signal and the zero-phase pulse train signal from the rotation angle sensor 30 are continuously supplied to the electrical angle converter 64 at a predetermined sampling period. The electrical angle conversion unit 64 calculates the electrical angle θ of the rotor of the motor 6 with respect to the stator based on the pulse train signals, and inputs the calculated electrical angle θ to the angular velocity conversion unit 65. The angular velocity conversion unit 65 calculates the angular velocity ω of the rotor with respect to the stator by differentiating the electrical angle θ. The angular velocity ω represents positive rotation of the rotor by positive, and negative rotation of the rotor by negative.

  Next, a booster circuit 100 that boosts the battery voltage and a booster circuit control device that controls the booster circuit 100 will be described. The booster circuit 100 corresponds to a booster circuit. In this embodiment, the booster circuit control device is also used by the control device 20.

The booster circuit 100 is provided in a current supply circuit between the in-vehicle battery (hereinafter referred to as a battery) B and the motor driving device 35.
In the booster circuit 100 of this embodiment, a boosting coil (hereinafter simply referred to as a coil) L and a transistor Q2 are connected between the application point P1 and the voltage application point P2. The transistor Q2 has a source connected to the coil L and a drain connected to the voltage application point P2. The gate of the transistor Q2 is connected to the CPU 21 of the control device 20. D2 is a parasitic diode of the transistor Q2.

The application point P1 is grounded through a rectifying capacitor C1. The voltage application point P2 is grounded via a boosting capacitor C2.
The capacitor C2 corresponds to a capacitor that smoothes the boosted voltage generated by the boosting coil.

  The transistor Q1 has a drain connected to a connection point between the coil L and the transistor Q2, and a source grounded. The gate of the transistor Q1 is connected to the CPU 21 of the booster circuit control device 101. D1 is a parasitic diode of the transistor Q1. In order to detect the voltage at the voltage application point P2, the voltage application point P2 is connected to a voltage input port (not shown) of the CPU 21 of the control device 20 so that the output voltage VBPIG can be detected.

  The transistors Q1 and Q2 are n-channel MOSFETs. The transistor Q1 constitutes a first switching element, and the transistor Q2 constitutes a second switching element.

Next, the control device 20 that controls the transistors Q1 and Q2 will be described.
FIG. 5 shows a functional block diagram of the control device 20. That is, it is a control block diagram showing functions executed by programs in the CPU 21.

Each unit illustrated in the control block diagram does not indicate independent hardware, but indicates a function executed by the CPU 21.
The control device 20 constitutes a booster circuit control means.

The CPU 21 includes a calculator 110, a PID controller 120, a PWM calculator 130, and an A / D converter 150.
The arithmetic unit 110 calculates a deviation between the target output voltage VBPIG * (20 V in this embodiment) stored in advance in the ROM 22 and VBPIG input via the A / D conversion unit 150, and sends it to the PID control unit 120. Supply that deviation.

  The PID control unit 120 is a circuit that performs proportional (P), integration (I), and differentiation (D) processing to reduce the deviation, and calculates the control amounts of the transistors Q1 and Q2. The control amount calculated by the PID control unit 120 is further converted into a duty ratio drive signal by calculating a duty ratio α corresponding to the control amount by the PWM calculation unit 130, and the converted duty ratio drive signal is converted into a booster circuit. Applied to 100 transistors Q1 and Q2. In the present embodiment, the calculated duty ratio drive signal is applied so as to alternately turn on and off the transistors Q1 and Q2 (see FIG. 6). This application is performed in the same way both during powering and regeneration of the motor 6.

  FIG. 6 shows a pulse signal (duty ratio drive signal) applied to the transistor Q1, where Tα is an ON time, T is a pulse period, and α is a duty ratio (ON duty) relating to the transistor Q1. Note that the duty ratio of the transistor Q2 is (1- | α |).

When the duty ratio α is “+”, it is in a power running state, and when it is “−”, it is in a regenerative state.
In the first embodiment, the duty ratio α in the power running state is 0 ≦ α ≦ α0 <1. α0 is a limit value, and when the result of calculating the duty ratio α by the PWM calculation unit 130 exceeds α0, α0 is determined as the duty ratio α.

The duty ratio α in the regenerative state is 0 ≦ | α | ≦ 1.
In addition, in the other embodiments including the first embodiment, when the transistor Q2 is turned on and off alternately with the transistor Q1, the duty ratio of the transistor Q2 can be calculated by (1− | α |), and thus is particularly refused. The description is omitted unless otherwise noted.

  Further, a pulse signal (duty ratio drive signal) that is turned off when the transistor Q1 is turned on and turned on when the transistor Q1 is turned off is applied to the transistor Q2. The duty ratio drive signal applied to transistors Q1 and Q2 has a frequency outside the audible frequency.

(Operation of the first embodiment)
In the present embodiment, the transistors Q1 and Q2 are alternately turned on and off at the time of power running and regeneration by the duty ratio drive signal of the drive pattern shown in FIG.

  More specifically, during powering, in the booster circuit 100, the transistor Q1 performs a switching operation by duty control based on the signal. As a result, energy is repeatedly accumulated and released in the coil L, and a high voltage appears upon emission on the drain side of the transistor Q2. That is, when the transistor Q1 is turned on and the transistor Q2 is turned off, a current flows through the transistor Q1 to the ground side (sometimes referred to as ground). Next, when the transistor Q1 is turned off, the current flowing through the coil L is cut off. When the current flowing through the coil L1 is interrupted, a high voltage is generated on the drain side of the transistor Q2 that is turned on so as to prevent a change in magnetic flux due to the interruption of the current. By repeating this, a high voltage is repeatedly generated on the drain side of the transistor Q2, smoothed (charged) by the capacitor C2, and generated at the point P2 as the output voltage VBPIG.

  At this time, the voltage boosted by the booster circuit 100 is related to the duty ratio α of the duty ratio drive signal output from the control device 20. If the duty ratio α is large, the output voltage VBPIG is high, and if the duty ratio α is small, the output voltage VBPIG is low.

  Next, when the motor 6 enters the regenerative state, the output voltage VBPIG rises, but the transistor Q2 is turned on by duty control even during regeneration. For this reason, a current flows through the battery B via the transistor Q2 and is absorbed.

The first embodiment has the following features.
(1) In the present embodiment, a d-axis command current Id * and a q-axis command current Iq * (motor control signal) are determined based on the vehicle speed V and the steering torque τ of the steering wheel 1, and a command current that outputs the signal A setting unit 54 (control signal generating means), a motor driving device 35 (motor driving means) for driving the motor 6 (electric motor) based on the d-axis command current Id * and the q-axis command current Iq * (motor control signal); I was prepared to. Then, a booster circuit 100 is provided in a current supply circuit between the battery B and the motor driving device 35 (electric motor driving means). The booster circuit 100 includes a coil L (boost coil) to which a battery voltage is applied with one end connected to the battery B, a transistor Q1 (first switching element) that grounds or opens the coil L, and a coil L A transistor Q2 (second switching element) connected to the other end side and turned on and off, and a capacitor C2 connected to the output side of the transistor Q2 and smoothing the output voltage (boost voltage) from the coil L are provided.

  Based on the deviation between the target output voltage VBPIG * and the output voltage VBPIG, the transistors Q1 and Q2 of the transistors Q1 and Q2 are alternately turned on and off to increase the supply voltage of the motor 6 during powering. Further, a control device 20 (boost circuit control means) for alternately turning on and off the transistors Q1 and Q2 during regeneration is provided.

As a result, even when the motor 6 is in a regenerative state, the booster circuit 100 is not destroyed.
(2) In the first embodiment, the booster circuit 100 is provided in the current supply circuit between the battery B and the motor driving device 35 (electric motor driving means). Further, the booster circuit 100 includes a coil L (boost coil) connected to the battery B, a transistor Q1 (first switching element) for grounding or opening the coil L, and a transistor Q2 (first switch) connected to the coil L. 2 switching elements) and a capacitor C2 for smoothing the output voltage.

  Based on the deviation between 20 V (target output voltage VBPIG *) and the output voltage VBPIG, the transistors Q1 and Q2 are alternately turned on and off during power running and regeneration to boost the supply voltage of the motor 6 (motor) and regenerate. And a control device 20 (boost circuit control means).

  Since the diode D is used in the conventional example, the amount of heat generated by the current flowing through the diode D when the transistor Q1 is turned off during powering is large. On the other hand, in the present embodiment, since the amount of heat generated (loss) due to the current that flows when the transistor Q2 is turned on is small, the efficiency can be increased.

  (3) Also, in the conventional example, when the motor 6 enters the regenerative state, the output voltage VBPIG rises due to the diode D, but no means for eliminating the voltage rise is provided. There is a risk that the circuit will be damaged due to excessive rise.

  On the other hand, in the present embodiment, during regeneration, even if the output voltage VBPIG increases, the transistor Q2 is turned on, so that a current flows through the battery B, and an increase in the output voltage VBPIG can be avoided.

  (4) In this embodiment, the duty ratio drive signals of the transistors Q1 and Q2 have a frequency outside the audible frequency. As a result, no abnormal noise is generated by the duty ratio drive signal during the boosting drive of the booster circuit 100, and uncomfortable feeling to the driver can be suppressed.

2. Second embodiment (reference embodiment)
Next, a second embodiment will be described with reference to FIG.
In the following embodiments including this embodiment, the same or corresponding components as those of the other embodiments (the first embodiment in the second embodiment) are denoted by the same reference numerals, and the description thereof is omitted. The explanation will focus on the differences.

In the second embodiment, the control device 20 of the first embodiment is further configured as a steering state determination unit, and the other configurations are the same as those of the first embodiment.
That is, in the first embodiment, the PID control unit 120 calculates the control amounts of the transistors Q1 and Q2, and the calculated control amount is converted into a corresponding duty ratio drive signal by the PWM calculation unit 130. When the duty ratio α at this time is “−”, the regeneration state is indicated, and when the duty ratio α is “+”, the power running state is indicated. Therefore, the PWM calculation unit 130 particularly corresponds to a steering state determination unit. The PWM calculation unit 130W applies a duty ratio drive signal to each of the transistors Q1 and Q2 according to when the duty ratio is “+” (power running state) and when the duty ratio is “−” (regenerative state).

  The duty ratio α of the second embodiment is 0 ≦ α ≦ α0 <1 in the power running state as in the first embodiment, and the result of calculating the duty ratio α by the PWM calculation unit 130 exceeds α0. Then, α0 is determined as the duty ratio α.

The duty ratio α in the regenerative state is 0 ≦ | α | ≦ 1, as in the first embodiment.
In the second embodiment, the duty ratio drive signal output from the PWM calculation unit 130 differs in the drive pattern of the transistors Q1 and Q2 during powering and regeneration of the motor 6 as shown in FIG.

During power running, the transistor Q1 is driven on and off, while the duty ratio drive signal is applied so that the transistor Q2 remains off.
During regeneration, a duty ratio drive signal is applied so that the transistors Q1 and Q2 are alternately driven on and off.

(Operation of Second Embodiment)
During power running, since the duty ratio α is “+”, a duty ratio drive signal for driving the transistor Q1 on and off is applied from the PWM calculation unit 130, while the duty ratio that keeps the transistor Q2 in the off state A drive signal is applied. Hereinafter, when the duty ratio α is “+”, it is said that “the control device 20 has determined that the motor 6 is in a power running state”, and when the duty ratio α is “−”, “the control device 20 is "It was determined that the motor 6 is in a regenerative state."

That is, when control device 20 determines that motor 6 is in a power running state, control device 20 controls transistor Q2 to be fully off.
Therefore, in booster circuit 100, only transistor Q1 performs a switching operation. As a result, the accumulation and release of energy are repeated in the coil L. At this time, as in the first embodiment, a high voltage upon emission appears on the drain side of the transistor Q2. This is because, even when the transistor Q2 is in the off state, the transistor Q2 has the parasitic diode D2, so that a high voltage is generated on the drain side of the transistor Q2 via the parasitic diode D2.

  In this way, a high voltage is generated on the drain side of the transistor Q2 by repeating ON / OFF driving of only the transistor Q1. By repeating this, a high voltage is repeatedly generated on the drain side of the transistor Q2, smoothed (charged) by the capacitor C2, and generated at the point P2 as the output voltage VBPIG.

  During regeneration, the duty ratio α is “−”, and therefore the duty ratio drive signal is applied from the PWM calculation unit 130 so that the transistors Q1 and Q2 are alternately driven on and off. That is, if control device 20 determines that motor 6 is in the regenerative state, control device 20 controls transistors Q1 and Q2 to be alternately turned on and off. For this reason, it becomes the same effect | action as 1st Embodiment at the time of regeneration.

  If this regenerative state is continuously performed, the duty ratio α is decreased, so that the transistor Q1 is completely turned off and only the transistor Q2 is turned on. In this way, the regenerative current flows into the battery B and is absorbed.

The second embodiment has the following features.
(1) In 2nd Embodiment, the control apparatus 20 (steering state determination means) which determines the power running and regeneration state of the motor 6 based on the deviation of target output voltage VBPIG * and output voltage VBPIG was provided. Furthermore, when the control device 20 determines that the power running state is established, only the transistor Q1 (first switching element) is turned on and off for control.

As a result, during power running, similar to the first embodiment, heat generation is less than in the conventional diode D, and loss can be reduced.
(2) When the control device 20 determines that the regenerative state, the transistors Q1 and Q2 are alternately turned on and off.

As a result, even during regeneration, an increase in the output voltage VBPIG can be avoided as in the first embodiment.
3. Third embodiment (reference embodiment)
Next, a third embodiment will be described with reference to FIG.

In the third to tenth embodiments, as in the second embodiment, the control device 20 (PWM calculation unit 130) constitutes a steering state determination unit.
In the third embodiment, the configuration is the same as that of the second embodiment, but the control is different. That is, during power running, a duty ratio drive signal is applied to the transistors Q1 and Q2 as in the second embodiment, but during regeneration, the following difference occurs.

  That is, at the time of regeneration, the PWM calculation unit 130 applies a duty ratio drive signal that is fully off to the transistor Q1, and applies a duty ratio drive signal that has a predetermined duty ratio to the transistor Q2. . In FIG. 8, Tα1 (= T × α) of the duty ratio drive signal applied to the transistor Q1 is the same as Tα in the second embodiment. On the other hand, a duty ratio drive signal having an on time of Tα2 = T × (1− | α |) is applied to the transistor Q2.

  The duty ratio α of the transistor Q1 in the power running state is 0 ≦ α ≦ α0 <1 as in the second embodiment, and the result of calculating the duty ratio α by the PWM calculation unit 130 is α0. If it exceeds, α0 is determined as the duty ratio α. The duty ratio (1- | α |) of the transistor Q2 in the regenerative state is 0 ≦ | α | ≦ 1.

The third embodiment has the following features.
(1) In 3rd Embodiment, the control apparatus 20 (steering state determination means) which determines the power running and regeneration state of the motor 6 based on the deviation of target output voltage VBPIG * and output voltage VBPIG was provided. The controller 20 controls only the transistor Q1 (first switching element) on / off when it is determined to be in the power running state, and controls only on / off of the transistor Q2 when it is determined as the regenerative state.

As a result, at the time of power running (power running state), the same effect as at the time of power running (power running state) of the second embodiment is achieved.
Further, since only the transistor Q2 is driven on / off during regeneration (regenerative state), similarly to the regenerative state (regenerative state) of the first embodiment, in this embodiment, the current flows when the transistor Q2 is turned on. Since the heat generation amount (loss) is small, the efficiency can be increased.

4). Fourth embodiment (reference embodiment)
Next, a fourth embodiment will be described with reference to FIGS. The configuration of the fourth embodiment is the same as that of the second embodiment, and the control is different from that of the second embodiment.

  That is, in the fourth embodiment, during power running, the transistors Q1 and Q2 are alternately turned on and off by the duty ratio drive signal from the PWM calculation unit 130 as shown in FIG. That is, if control device 20 determines that it is in the power running state, it controls on / off drive of transistors Q1 and Q2. In the present embodiment, in FIG. 9, the calculation process of the duty ratio α is performed every calculation cycle of 200 μsec, and the calculation result is reflected in the on / off drive of the transistor Q1 immediately after the calculation. The pulse period T is 50 μsec.

  Also, during regeneration, as shown in FIG. 10, a duty ratio drive signal that is fully off is applied to the transistor Q1 as in the third embodiment, and a duty ratio drive signal that is a predetermined duty ratio is applied to the transistor Q2. Have been to. That is, when determining that the controller 20 is in the regenerative state, the control device 20 turns off the transistor Q1 and controls on / off driving of the transistor Q2.

In the fourth embodiment, the duty ratio α in the power running state is the same as that in the first embodiment.
The duty ratio (1- | α |) of the transistor Q2 in the regenerative state of the fourth embodiment is 0 ≦ | α | ≦ 1.

Therefore, the fourth embodiment has the following features.
(1) In 4th Embodiment, the control apparatus 20 (steering state determination means) which determines the power running and regeneration state of the motor 6 based on the deviation of target output voltage VBPIG * and output voltage VBPIG was provided. When the control device 20 determines that it is in the power running state, the transistors Q1 and Q2 are alternately turned on / off, and when it is determined that it is in the regenerative state, only the transistor Q2 is controlled to be on / off.

  Even if it does in this way, at the time of power running (power running state), there exists an effect similar to the effect at the time of power running (power running state) of a 1st embodiment. Further, during the power running (power running state) of the second and third embodiments, the transistor Q2 is completely turned off, and the voltage is boosted by charging the capacitor C2 via the parasitic diode D2. For this reason, the parasitic diode D2 generates heat during power running (power running state). In contrast, in the present embodiment, the transistor Q2 is turned on for boosting during powering (powering state), and the amount of heat generated (loss) due to the current that flows when the transistor Q2 is turned on is less than that of the parasitic diode D2. Yes. For this reason, the efficiency at the time of boosting (powering) can be increased.

Further, at the time of regeneration, the same effect as that at the time of regeneration (regeneration state) of the third embodiment is achieved.
5. Fifth embodiment (reference embodiment)
Next, a fifth embodiment will be described with reference to FIGS.

  In the present embodiment, the bootstrap circuit BS is connected between the application point P1 and the drain of the transistor Q1 in the configuration of the first embodiment, and other configurations are the same as those of the first embodiment. Yes. The bootstrap circuit BS includes a diode D3 and a bootstrap capacitor (hereinafter simply referred to as a capacitor) C3. The anode of the diode D3 is connected to the application point P1, and the cathode is connected to the capacitor C3.

  Although not described in the first to fourth embodiments, unlike the fifth embodiment, a charge pump (not shown) is connected to the gate of the transistor Q2 in the control device 20 in the first to fourth embodiments. The gate potential can be applied when necessary. Therefore, for example, as described in the operation of the third and fourth embodiments, the transistor Q2 is applied from the drive power supply (charge pump) and can be turned on / off even when the transistor Q1 is fully turned off during regeneration. ing.

In the fifth embodiment, the control device 20 further includes a pre-driver 24 composed of an IC connected to the CPU 21. The predriver 24 constitutes predriver means.
The cathode of the diode D3 is connected to the VB terminal of the pre-driver 24.
The VS terminal of the pre-driver 24 is connected to the drain of the transistor Q1. The pre-driver 24 can apply the voltage charged in the capacitor C3 to the gate of the transistor Q2 via the HO terminal based on the duty ratio drive signal related to the transistor Q2 from the CPU 21.

  The application point P1 is connected to the VCC terminal of the pre-driver 24. The pre-driver 24 can apply the voltage at the application point P1 (DC 12 V in this embodiment) to the gate of the transistor Q1 via the LO terminal based on the duty ratio drive signal related to the transistor Q1 from the CPU 21. .

(Function)
Next, the operation of the fifth embodiment will be described.
If the control device 20 determines that the motor 6 is in the power running state as in the fourth embodiment, the control device 20 alternately controls the transistors Q1 and Q2 (see FIG. 12). At this time, when the transistor Q1 is turned on, the drain of the transistor Q1 falls to the ground potential. Then, the capacitor C3 is charged to the potential (DC12V) at the application point P1. When the transistor Q1 is turned off next, the drain potential of the transistor Q1 becomes 12V, so that the potential at the connection point between the diode D3 and the capacitor C3 becomes 24V.

Thus, when the transistor Q1 is turned off, the potential at the connection point between the diode D3 and the capacitor C3 can be made higher than the source potential of the transistor Q2.
Therefore, the voltage of the capacitor C3 is applied to the gate of the transistor Q2 based on the duty ratio drive signal (in the case of an ON signal) related to the transistor Q2. At this time, since the gate potential Vg of the transistor Q2 is higher than the source potential Vs, the transistor Q2 is turned on.

In the present embodiment, the calculation cycle of the duty ratio α is performed in the same cycle as in the fourth embodiment regardless of the power running state and the regenerative state.
Further, when determining that the motor 6 is in the regenerative state, the control device 20 controls the transistors Q1 and Q2 as shown in FIG.

  That is, the control device 20 performs control so that the first period Ta in which the transistors Q1 and Q2 are alternately turned on and off and the second period Tb in which the transistor Q1 is turned off and only the transistor Q2 is turned on and off repeatedly exist.

  In the fifth embodiment, the first period Ta corresponds to a charging period and corresponds to a non-reflecting period in which the α calculation is not reflected. The second period Tb corresponds to the discharge period and also corresponds to the reflection period reflected by the α calculation.

  That is, the control device 20 drives the transistors Q1 and Q2 on and off at a fixed period (in this embodiment, every 200 μsec, which is the calculation period) at a fixed duty ratio α1 and a fixed duty ratio (1- | α1 |), respectively. .

  Therefore, the on-duty time To (To = pulse period × α1) of the transistor Q1 during the first period Ta is a fixed value. During the first period Ta, the transistor Q1 is driven on and off at a fixed duty ratio α1 to charge the capacitor C3. Note that the fixed duty ratio α1 data is stored in the ROM 22 in advance, and when the control device 20 determines that it is in the regenerative state, PWM control is performed in the first period Ta based on this value. In the present embodiment, the pulse period is 50 μsec.

  In the second period Tb, the on-duty time To is a value that allows the gate potential Vg of the transistor Q2 to be kept higher than the source potential Vs even when the transistor Q1 is turned off. That is, if the gate potential Vg is always higher than the source potential Vs, the transistor Q2 can be controlled to be on.

  Note that the duty ratio α and the duty ratio (1− | α |) in the power running state in the fifth embodiment are the same as those in the first embodiment. In the regenerative state control, the duty ratio (1- | α |) of the transistor Q2 includes a 100% duty ratio at which the transistor Q2 is fully turned on. That is, 0 ≦ | α | ≦ 1.

Therefore, according to the fifth embodiment, the following effects are obtained.
(1) In 5th Embodiment, the control apparatus 20 (steering state determination means) which determines the power running and regeneration state of the motor 6 based on the deviation of target output voltage VBPIG * and output voltage VBPIG was provided. The first switching element and the second switching element are composed of transistors Q1 and Q2 of n-channel MOSFETs. Further, a bootstrap circuit BS is provided which is connected between the battery B and the drain of the transistor Q1 and generates a voltage to be applied to the gate of the transistor Q2. The bootstrap circuit BS includes a capacitor C3 (bootstrap capacitor) so that the potential of the capacitor C3 can be applied to the gate of the transistor Q2.

  On the other hand, when the control device 20 determines that it is in the power running state, the transistors Q1 and Q2 are alternately turned on and off. When the regeneration state is determined, the transistor Q2 is turned on / off, the transistor Q1 is turned on / off at a fixed duty ratio α1, and the first period Ta (200 μsec), and the transistor Q1 is held off. Control was performed at regular intervals including Tb (200 μsec).

  As described above, the fifth embodiment is different from the case where the power source of the transistor Q2 is secured by the charge pump method of the first embodiment or the like. That is, the bootstrap circuit BS is used as a power source for the gate of the transistor Q2 in the power running state and the regenerative state.

When the power source of the transistor Q2 is used by the charge pump method as in the first embodiment, the transistor Q2 operates without any problem even in the regenerative state even when the transistor Q2 is fully turned on.
However, when the bootstrap circuit BS is provided as in the fifth embodiment, the capacitor C3 is not charged unless the transistor Q1 is turned on during regeneration. For this reason, the capacitor C3 is discharged, and eventually the gate potential Vg falls below the source potential Vs, the transistor Q2 cannot be turned on, and the regenerative current cannot be absorbed.

  However, in the fifth embodiment, since the first period Ta for PWM control of the transistor Q1 with the fixed duty ratio α1 is provided at the time of regeneration, the transistor Q2 is sufficiently obtained even if the capacitor C3 is discharged in the second period Tb. There is an effect that can be driven on and off.

As a result, the regenerative current can be absorbed by the battery even in the regenerative state.
The fifth embodiment may be as follows.
In the fifth embodiment, during regeneration, the transistor Q1, which is the first switching element, is controlled to be turned on and off at a fixed duty ratio at regular intervals. Instead, in the first period Ta, the transistor Q1 may be on / off controlled with a fixed duty ratio, and the second period Tb may be on / off controlled with a variable duty ratio.

6). Sixth embodiment (reference embodiment)
Next, a sixth embodiment will be described with reference to FIGS. The sixth embodiment is the same as the circuit configuration of the fifth embodiment and is a modified embodiment of the control during regeneration. Therefore, the same reference numerals are given to the same configurations as the fifth embodiment. The description is omitted.

  16 and 17 are for illustrating the operation of the booster circuit 100. For convenience of explanation, circuits such as the bootstrap circuit BS are omitted, and the substantial operation of the booster circuit 100 in this embodiment is shown. Is shown in an equivalent circuit.

FIG. 14 is a control block diagram illustrating functions executed by the control program during regeneration in the CPU 21 of the control device 20.
In the sixth embodiment, a guard function unit 140 is provided between the PWM calculation unit 130 and the booster circuit 100 as shown in FIG.

In the present embodiment, control during powering is performed in the same manner as in the fifth embodiment.
In the control during regeneration, unlike the fifth embodiment, PWM control is performed so that the transistor Q1 is fully turned off and the transistor Q2 is driven on and off. The duty ratio (1- | α |) of the transistor Q2 is guarded (limited) so that the transistor Q2 is not fully turned on, in other words, can always be turned off.

  Specifically, when the duty ratio | α | calculated by the PWM calculation unit 130 is calculated by the PWM calculation unit 130, | α | is a guard value (limit value) αg (0 ≦ | α | <αg <1 ) Exceeds α). That is, in this case, the transistor Q2 is turned on with a duty ratio (1-αg).

  When the duty ratio is equal to or less than the guard value αg, the gate potential Vg of the transistor Q2 is maintained higher than the source potential Vs by charging the capacitor C3 when the transistor Q2 described later is turned off (during mode II). Has been. That is, in mode II, the transistor Q2 is always set to be turned off.

FIG. 15 shows a drive pattern of the transistors Q1 and Q2 in the regenerative state.
As shown in the figure, also in the present embodiment, the driving pattern is such that the first period Ta and the second period Tb are alternately repeated. In the sixth embodiment, similarly to the fifth embodiment, the first period Ta corresponds to a charging period and corresponds to a non-reflecting period in which the α calculation is not reflected. The second period Tb corresponds to the discharge period and also corresponds to the reflection period reflected by the α calculation.

In the sixth embodiment, mode I and mode II are alternately repeated during the first period Ta.
In the first period Ta mode I shown in FIG. 15 (transistor Q2 is on and transistor Q1 is off), as shown in FIG. 16, the regenerative power generated by the motor 6 is supplied to the regenerative current I1 through the transistor Q2 and the coil L. Flows into the battery B and is absorbed.

  Further, in mode II (transistor Q2 is off, transistor Q1 is off) in the first period Ta shown in FIG. That is, when the mode I transitions to the mode II, the transistor Q2 is turned off as shown in FIG. However, the current flowing through the coil L and the winding (not shown) of the motor 6 does not immediately become zero. In the coil L, the parasitic diode D1 of the transistor Q1 is turned on, and the current I2 flows from GND (ground) → the transistor Q1 → the coil L → the battery B, and the electromagnetic energy stored in the coil L is absorbed by the battery B.

  At this time, since the potential at the connection point P3 between the coil L and the cathode of the parasitic diode D1 falls to the GND (ground) potential when the parasitic diode D1 is turned on, the capacitor C3 can be charged.

On the other hand, in the winding (not shown) of the motor 6, the transistor Q2 is turned off, and the route through which the regenerative current flows is interrupted, so that the regenerative current I3 charges the capacitor C2.
Thus, in mode II, the transistor Q2 is always turned off and the capacitor C3 of the bootstrap circuit BS is charged. As a result, the gate potential Vg of the transistor Q2 can be maintained higher than the source potential Vs, and the transistor Q2 can be turned on thereafter. That is, in the sixth embodiment, the transistor Q1 is completely turned off in the regenerative state, but in the mode II as described above, the transistor Q2 is always turned off and the capacitor C3 is charged, so that the transistor Q2 can be turned on. It is.

In the second period Tb, the α calculation is reflected as in the fifth embodiment, and the transistor Q2 is driven on and off by PWM control.
The sixth embodiment has the following effects.

(1) In the sixth embodiment, the control device 20 (steering state determining means) that determines the power running and regenerative state of the motor 6 based on the deviation between the target output voltage VBPIG * and the output voltage VBPIG is provided.
The first switching element and the second switching element are composed of transistors Q1 and Q2 of n-channel MOSFETs. Furthermore, a bootstrap circuit BS is provided which is connected to the battery B and the drain of the transistor Q1 and generates a voltage to be applied to the gate of the transistor Q2.

On the other hand, when the control device 20 determines that it is in the power running state, the transistors Q1 and Q2 are alternately turned on and off.
If the regeneration state is determined, the transistor Q1 is completely turned off, and only the transistor Q2 (second switching element) is PWM-controlled for on / off control. In the PWM control, a predetermined duty ratio (1-αg) is exceeded. The duty is limited so that PWM control is not performed. That is, the transistor Q2 is subjected to PWM control so as to be controlled so as to include a period in which the transistor Q2 is always turned off.

  As a result, in the regenerative state, the transistor Q2 is always turned off. Therefore, during the time when the transistor Q2 is off (period of mode II), the current I2 flows from GND (ground) → transistor Q1 (parasitic diode D1) → coil L → battery B and is stored in the coil L. Electromagnetic energy can be absorbed by the battery B.

  Further, when the parasitic diode D1 is turned on, the connection point between the capacitor C3 and the parasitic diode D1 becomes the GND potential, so that the capacitor C3 can be charged and the transistor Q2 can be driven.

  (2) Also in the sixth embodiment, since the transistor Q2 is turned on in the regenerative state, the amount of heat generated (loss) due to the current flowing when the transistor Q2 is turned on is small, so that the efficiency can be improved.

7). Seventh embodiment (reference embodiment)
Next, a seventh embodiment will be described with reference to FIG. 2, FIG. 18, and FIG.
The seventh embodiment is the same as the configuration of the fourth embodiment and the control of the transistors Q1 and Q2 during regeneration of the fourth embodiment. The control of the transistors Q1 and Q2 in the power running state is different from that in the fourth embodiment.

The control device 20 of the present embodiment constitutes a steering state determination unit and a load state determination unit that determines the load state of the motor 6.
The control device 20 as the load state determination means determines whether the load state of the motor 6 is high load or low load based on the steering torque τ (steering torque signal) input by the CPU 21 as shown in FIG. . In the present embodiment, 0 is adopted as the determination reference value, a low load is determined when the steering torque τ is 0, and a high load is determined in other cases.

  Note that the determination reference value may be other than 0. In short, the case where the boost circuit 100 detects a steering torque τ that is equal to or less than the determination reference value when the value when boosting is not required is used as the determination reference value. A low load may be assumed, and a high load may be assumed otherwise.

  Then, when the control device 20 determines that the power running state and the load state of the motor 6 is high load, as shown in FIG. 18, as in the power running state of the fourth embodiment, Transistors Q1 and Q2 are alternately turned on and off. When the control device 20 determines that the power running state is determined and the load state of the motor 6 is high, the transistor Q1 is driven on and off as in the power running state of the second embodiment. On the other hand, the transistor Q2 may be completely turned off (FIG. 7).

  When the control device 20 determines that the power running state and the load state of the motor 6 is low, the transistor Q1 is driven on and off by PWM control as shown in FIG. A duty ratio driving signal for turning off Q2 is applied.

As a result, when the load state of the motor 6 is low, the transistor Q2 is completely turned off and the transistor Q2 is not turned on.
The seventh embodiment has the following effects.

  (1) In the seventh embodiment, the control device 20 (steering state determining means) that determines the power running and regenerative state of the motor 6 based on the deviation between the target output voltage VBPIG * and the output voltage VBPIG is provided. The control device 20 is configured to determine whether the load state of the motor 6 (electric motor) is high load or low load based on the steering torque τ (steering torque signal) (load state determination means).

  When determining that the power running state is present and the load state of the motor 6 is a low load, the control device 20 performs on / off control (PWM control) only on the transistor Q1 (first switching element) and turns on the transistor Q2. It was controlled to turn it all off. Further, when it is determined that the power running state and the load state of the motor 6 is high, both the transistors Q1 and Q2 are alternately turned on / off (PWM control).

On the other hand, when the control device 20 determines that the regenerative state is present, only the transistor Q2 (second switching element) is turned on / off (PWM control).
As a result, when the motor 6 is in a power running state and the load state of the motor 6 is low, particularly in the case of no load in the present embodiment, the transistor Q2 is completely turned off, so that the transistor Q2 does not generate heat and the switching is performed. Loss (loss) is eliminated and efficiency can be increased.

  When the steering torque τ becomes 0, the duty ratio α of the transistor Q1 is 0% (on-duty time Tα = 0), so that the transistor Q1 is completely turned off and the switching loss of the transistor Q1 is also reduced. Disappear.

(2) At the time of regeneration, the same effects as at the time of regeneration of the fourth embodiment are achieved.
8). Eighth embodiment (reference embodiment)
Next, an eighth embodiment will be described.

  In the seventh embodiment, the charge pump is used as the power source of the transistor Q2. In the eighth embodiment, in the configuration of the seventh embodiment, the bootstrap circuit BS is provided as the power source of the transistor Q2 instead of the charge pump. Is different. That is, the configuration of the eighth embodiment is different from that of the fifth embodiment.

  In the eighth embodiment, when the control device 20 determines the power running state as the steering state determination unit as in the seventh embodiment, the control device 20 functions as the load state determination unit and the load state of the motor 6 is low. It is determined whether the load is high or not. When it is determined that the load is high, the control device 20 applies a duty ratio drive signal to the transistors Q1 and Q2 as shown in FIG. 18 as in the seventh embodiment. If it is determined that the load is low, a duty ratio drive signal is applied to the transistors Q1 and Q2 as shown in FIG. 19 as in the seventh embodiment.

Further, when the control device 20 determines that the regeneration is in progress, a duty ratio drive signal is applied to the transistors Q1 and Q2 as shown in FIG. 13 as in the fifth embodiment.
As a result, the following effects are achieved in the eighth embodiment.

  (1) In the eighth embodiment, the control device 20 (steering state determining means) that determines the power running and regenerative state of the motor 6 based on the deviation between the target output voltage VBPIG * and the output voltage VBPIG is provided. The first switching element and the second switching element are composed of transistors Q1 and Q2 of n-channel MOSFETs. Furthermore, a bootstrap circuit BS is provided which is connected to the battery B and the drain of the transistor Q1 and generates a voltage to be applied to the gate of the transistor Q2. The bootstrap circuit BS is configured to include a capacitor C3, and the capacitor is connected to the gate of the transistor Q2 (second switching element) so that the potential of the capacitor C3 can be applied.

  When determining that the power running state is present and the load state of the motor 6 is a low load, the control device 20 performs on / off control (PWM control) only on the transistor Q1 (first switching element) and turns on the transistor Q2. It was controlled to turn it all off. Further, when it is determined that the power running state and the load state of the motor 6 is high, both the transistors Q1 and Q2 are alternately turned on / off (PWM control).

As a result, the same effect as the effect (1) of the seventh embodiment is obtained.
(2) In the eighth embodiment, when the control device 20 determines that it is in the regenerative state, the first period Ta during which the transistors Q1 and Q2 are turned on and off at a fixed duty ratio α1 and the transistor Q1 are held off. In addition, the control is performed in a cycle including the second period Tb in which the transistor Q2 is controlled to be turned on / off.

As a result, the same effect as the effect (1) of the fifth embodiment is obtained.
9. Ninth embodiment (reference embodiment)
Next, a ninth embodiment will be described.

  The ninth embodiment has the same configuration as the hardware configuration of the eighth embodiment, and controls the power running state similarly to the eighth embodiment. The ninth embodiment differs from the eighth embodiment in the control during the regenerative state.

In the present embodiment as well, as in the eighth embodiment, the control device 20 constitutes a steering state determination unit and a load state determination unit.
When the control device 20 determines that it is in the regenerative state, it applies a duty ratio drive signal to the transistors Q1 and Q2 as shown in FIG. 15 as in the sixth embodiment.

As a result, the ninth embodiment has the following effects.
(1) A control device 20 (steering state determining means) that determines the power running and regenerative state of the motor 6 based on the deviation between the target output voltage VBPIG * and the output voltage VBPIG is provided. The first switching element and the second switching element are composed of transistors Q1 and Q2 of n-channel MOSFETs. Furthermore, a bootstrap circuit BS is provided which is connected to the battery B and the drain of the transistor Q1 and generates a voltage to be applied to the gate of the transistor Q2. The bootstrap circuit BS is configured to include a capacitor C3, and the capacitor is connected to the gate of the transistor Q2 (second switching element) so that the potential of the capacitor C3 can be applied.

  When determining that the power running state is present and the load state of the motor 6 is a low load, the control device 20 performs on / off control (PWM control) only on the transistor Q1 (first switching element) and turns on the transistor Q2. It was controlled to turn it all off. Further, when it is determined that the power running state and the load state of the motor 6 is high, both the transistors Q1 and Q2 are alternately turned on / off (PWM control).

As a result, the same effect as the effect (1) of the seventh embodiment is obtained.
(2) When the controller 20 determines that the regenerative state is present, the transistor Q1 is completely turned off, and only the transistor Q2 (second switching element) is PWM-controlled for on / off control. The duty is limited so that PWM control is not performed beyond (1-αg). That is, the transistor Q2 is subjected to PWM control so as to include on / off control so as to include a period during which the transistor Q2 is always turned off.

  As a result, in the regenerative state, the transistor Q2 is always turned off. Therefore, during the time when the transistor Q2 is off (period of mode II), the current I2 flows from GND (ground) → transistor Q1 (parasitic diode D1) → coil L → battery B and is stored in the coil L. Electromagnetic energy can be absorbed by the battery B.

  Further, when the parasitic diode D1 is turned on, the connection point between the capacitor C3 and the parasitic diode D1 becomes the GND potential, so that the capacitor C3 can be charged and the transistor Q2 can be driven.

10. Tenth embodiment (reference embodiment)
Next, a tenth embodiment will be described with reference to FIGS.
In the tenth embodiment, the same components as those in the fifth embodiment will be denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on differences from the components in the fifth embodiment.

  In the fifth embodiment, the anode of the diode D3 is connected to the application point P1. On the other hand, the present embodiment is different in that the anode of the diode D3 constituting the bootstrap circuit BS is connected to the voltage application point P2, that is, the drain of the transistor Q2.

Other configurations are the same as those of the fifth embodiment.
For example, the pre-driver 24 applies the voltage charged to the capacitor C3 to the gate of the transistor Q2 via the HO terminal based on the duty ratio drive signal related to the transistor Q2 from the CPU 21. Further, the pre-driver 24 applies the voltage at the application point P1 (DC 12 V in this embodiment) to the gate of the transistor Q1 via the LO terminal based on the duty ratio drive signal related to the transistor Q1 from the CPU 21.

In the present embodiment, the control device 20 constitutes a steering state determination unit.
(Function)
The operation of the tenth embodiment configured as described above will be described.

  If the control device 20 determines that the motor 6 is in the power running state as in the fifth embodiment, the transistors Q1 and Q2 are alternately turned on and off (see FIG. 12). As a result, energy is repeatedly accumulated and released in the coil L, and a high voltage at the time of emission appears on the drain side of the transistor Q2.

  That is, when the transistor Q1 is turned on and the transistor Q2 is turned off, a current flows to the ground side via the transistor Q1. Next, when the transistor Q1 is turned off, the current flowing through the coil L is cut off. When the current flowing through the coil L1 is interrupted, a high voltage is generated on the drain side of the transistor Q2 that is turned on so as to prevent a change in magnetic flux due to the interruption of the current. By repeating this, a high voltage is repeatedly generated on the drain side of the transistor Q2, smoothed (charged) by the capacitor C2, and generated at the point P2 as the output voltage VBPIG.

  In this way, since the drain potential of the transistor Q2 rises, the capacitor C3 of the bootstrap circuit BS also rises due to the bootstrap function. That is, when the transistor Q1 is turned on, the drain of the transistor Q1 falls to the ground potential. Then, the capacitor C3 is charged to the potential at the voltage application point P2 (the drain potential of the transistor Q2). When the transistor Q1 is turned off next, the drain potential of the transistor Q1 becomes 12V, so that the potential at the connection point between the diode D3 and the capacitor C3 becomes “12V + the drain potential of the transistor Q2.”

Thus, when the transistor Q1 is turned off, the potential at the connection point between the diode D3 and the capacitor C3 can be made higher than the source potential of the transistor Q2.
Therefore, the voltage of the capacitor C3 is applied to the gate of the transistor Q2 based on the duty ratio drive signal (in the case of an ON signal) related to the transistor Q2. At this time, since the gate potential Vg of the transistor Q2 is higher than the source potential Vs, the transistor Q2 is turned on.

If the control device 20 determines that the motor 6 is in the regenerative state, the control device 20 turns off the transistor Q1 and turns on / off the transistor Q2 (PWM control).
In this case, since it is in the regenerative state, the drain potential of the transistor Q2 rises due to the regenerative power generated by the motor 6 even if the transistor Q1 is fully turned off. Therefore, when the transistor Q1 is turned off, the drain potential of the transistor Q1 becomes 12V, and the potential at the connection point between the diode D3 and the capacitor C3 becomes “12V + the drain potential of the transistor Q2.”

As a result, when the transistor Q1 is off, the potential at the connection point between the diode D3 and the capacitor C3 can be made higher than the source potential of the transistor Q2.
Therefore, the voltage of the capacitor C3 is applied to the gate of the transistor Q2 based on the duty ratio drive signal (in the case of an ON signal) related to the transistor Q2. At this time, since the gate potential Vg of the transistor Q2 is higher than the source potential Vs, the transistor Q2 is turned on.

Therefore, according to the tenth embodiment, the following effects are obtained.
(1) In the tenth embodiment, the control device 20 (steering state determining means) that determines the power running and regenerative state of the motor 6 based on the deviation between the target output voltage VBPIG * and the output voltage VBPIG is provided.

  The first switching element and the second switching element are composed of transistors Q1 and Q2 of n-channel MOSFETs. Further, a bootstrap circuit BS including a capacitor C3 (bootstrap capacitor) is connected to the drain of the transistor Q2, and the potential of the capacitor C3 is applied by using the bootstrap circuit BS as a drive source of the transistor Q2 (second switching element). The capacitor C3 is connected to the gate of the transistor Q2 as possible.

On the other hand, when it is determined that the power running state is established, the control device 20 alternately performs on / off control of the transistors Q1 and Q2, and when it is determined that the regeneration state is established, the control device 20 performs only on / off control of the transistor Q2.
As a result, also in the tenth embodiment, in the regenerative state, the drain potential of the transistor Q2 rises due to the regenerative power even when the transistor Q1 is fully turned off. As a result, the gate potential Vg of the transistor Q2 becomes higher than the source potential Vs. Make it high. For this reason, since the transistor Q2 can be controlled on and off, the regenerative current can be absorbed by the battery B.

(2) The tenth embodiment has the following advantages compared to the connection configuration of the bootstrap circuit BS of the fifth embodiment.
In the fifth embodiment, at the time of regeneration, by providing a first period Ta for PWM control of the transistor Q1 at a fixed duty ratio α1, the transistor Q2 is driven on and off even if the capacitor C3 is discharged in the second period Tb. I was able to do it. On the other hand, in the tenth embodiment, since the transistor Q1 can be completely turned off, the heat generated by the transistor Q1 is eliminated, and the efficiency can be increased.

  (3) The charge pump method is a costly circuit, but in the tenth embodiment, the charge pump method is not adopted and a simple circuit composed of a diode and a capacitor can be used. It can be made cheaper than the charge pump system. Moreover, the performance at the time of regeneration can obtain the performance equivalent to a charge pump system.

11. The eleventh exemplary type state then the eleventh embodiment will be described with reference to FIGS. 21 and 22.
The eleventh embodiment is the same as the configurations of the second embodiment and the first embodiment, and the difference is that the target output voltage VBPIG * is made variable.

The control device 20 that controls the transistors Q1 and Q2 of this embodiment will be described.
FIG. 21 shows a functional block diagram of the control device 20. That is, it is a control block diagram showing functions executed by programs in the CPU 21.

Each unit illustrated in the control block diagram does not indicate independent hardware, but indicates a function executed by the CPU 21. The control device 20 constitutes a booster circuit control means.
The CPU 21 includes a target output voltage setting unit 160, a calculator 110, a PID control unit 120, a PWM calculation unit 130, and an A / D conversion unit 150.

Since the computing unit 110, the PID control unit 120, the PWM computing unit 130, and the A / D conversion unit 150 have been described in the first embodiment, refer to those descriptions.
In the first embodiment and the second embodiment, the target output voltage VBPIG * is constant, for example, 20V. On the other hand, in this embodiment, the target output voltage VBPIG * is made variable by the target output voltage setting unit 160 according to the q-axis command current Iq *. Specifically, as shown in FIG. 21, the target output voltage setting unit 160 reduces the target output voltage VBPIG * in the region M3 where the q-axis command current Iq * is large as compared to the regions M1 and M2 where it is not. Set. That is, the target output voltage setting unit 160 is configured by a two-dimensional map including the q-axis command current Iq * and the target output voltage VBPIG *, and is stored in the ROM 22. Then, when the q-axis command current Iq * is input, the CPU 21 calculates the target output voltage VBPIG * using this two-dimensional map.

  This is because, for example, at the time of large output such as stationary driving or low-speed traveling, it is not necessary to increase the pressure because the follow-up performance of the motor rotation speed is not required. In this case, the boosting transistors Q1 and Q2 may be completely stopped. Since the q-axis command current Iq * enters the large region M3 at low speed (including the case where the vehicle speed is 0), the target output voltage VBPIG * is decreased in the region M3 where the q-axis command current Iq * is large. is there. As a result, the booster circuit 100 stops boosting or lowers the boosting level below the regions M1 and M2.

  Further, in medium and high speed running, the q-axis command current Iq * is not so necessary, but since it is the region M2 that the motor rotational speed is desired, the booster circuit 100 is at a level higher than the region M3 where the q-axis command current Iq * is large. The pressure is increased at

  Further, in high-speed traveling, the followability of the motor rotational speed is required, so that the region M1 needs to be boosted. For this reason, the booster circuit 100 boosts the voltage at a level higher than the region M2 where the q-axis command current Iq * is large.

Control in the power running state and the regenerative state is performed in the same manner as in the second embodiment as shown in FIG.
The effects of the eleventh embodiment are as follows.

(1) Also in the eleventh embodiment, the same control as that in the second embodiment is performed during powering and regeneration, so that the same effect as in the second embodiment can be obtained.
(2) In the eleventh embodiment, the control device 20 (boost circuit control means) includes a target output voltage setting unit 160 (target output voltage setting means) for setting the target output voltage VBPIG * of the boost circuit 100, and the target output voltage. A PID control unit 120 that performs PID control calculation based on a deviation between VBPIG * and the output voltage VBPIG (at least a control calculation unit that performs P control), and performs a PWM calculation based on a calculation value of the PID control unit 120 to calculate a duty ratio The PWM calculation unit 130 (PWM calculation means) is included. The first and second switching elements Q1, Q2 are controlled to be turned on / off based on the duty ratio α calculated by the PWM calculation unit 130.

  Further, when the target output voltage setting unit 160 receives a q-axis command current Iq * (motor control signal) that is an operation status parameter of the motor 6, the target output voltage VBPIG * is made variable according to the value.

  As a result, at the time of large output such as stationary driving and low speed driving, the followability of the motor speed is not required. In these cases, in the region M3 where the q-axis command current Iq * is large compared to the case where it is not. Reduce the target output voltage VBPIG *. For this reason, heat generation in the coil L and the transistors Q1 and Q2 can be suppressed, loss is eliminated, and efficiency can be increased.

12 The twelfth form state then the twelfth embodiment will be described with reference to FIG. 23.
The twelfth embodiment is obtained by changing a part of the eleventh embodiment.

  The target output voltage setting unit 160 of the eleventh embodiment is configured by a two-dimensional map composed of the q-axis command current Iq * and the target output voltage VBPIG *. The target output voltage setting unit 160 of this embodiment is different in that it is configured by a two-dimensional map composed of the vehicle speed V and the target output voltage VBPIG *.

  That is, in the present embodiment, the target output voltage VBPIG * is made variable according to the vehicle speed V by the target output voltage setting unit 160. Specifically, as shown in FIG. 23, the target output voltage setting unit 160 sets the target output voltage VBPIG * to be smaller when the vehicle speed V is the low speed travel region V1 than when the vehicle speed V is not the regions V2 and V3. This map is stored in the ROM 22. Then, when the vehicle speed V is input, the CPU 21 uses this two-dimensional map to calculate the target output voltage VBPIG *.

Therefore, in the twelfth embodiment, the following operation is performed.
Also in the twelfth embodiment, as in the eleventh embodiment, the follow-up performance of the motor speed is not required at the time of large output such as stationary driving and low-speed traveling, so that there is no need to increase the pressure. Therefore, in the case of low speed running, the boosting transistors Q1 and Q2 may be completely stopped in this case. The target output voltage VBPIG * is decreased in the low speed (including the case where the vehicle speed is 0) travel region V1. As a result, the booster circuit 100 stops boosting or lowers the boosting level below the regions V2 and V3.

Further, in the medium / high speed traveling region V2, since it is a region desired by the number of motor revolutions, the booster circuit 100 boosts the pressure at a level higher than that in the low speed traveling region V1.
Further, the high-speed traveling region V3 is a region that needs to be boosted because the followability of the motor rotation speed is required. For this reason, the voltage is boosted by the booster circuit 100 at a level higher than that of the medium / high speed traveling region V2.

Control in the power running state and the regeneration state is similarly performed as shown in FIG. 22 of the eleventh embodiment.
Accordingly, the twelfth embodiment has the following effects.

(1) The same effects as (1) of the eleventh embodiment are achieved.
(2) In the twelfth embodiment, the control device 20 (boost circuit control means) includes a target output voltage setting unit 160 (target output voltage setting means) for setting a target output voltage VBPIG * of the boost circuit 100, and a target output voltage. A PID control unit 120 that performs PID control calculation based on a deviation between VBPIG * and the output voltage VBPIG (at least a control calculation unit that performs P control), and performs a PWM calculation based on a calculation value of the PID control unit 120 to calculate a duty ratio The PWM calculation unit 130 (PWM calculation means) is included. The first and second switching elements Q1, Q2 are controlled to be turned on / off based on the duty ratio α calculated by the PWM calculation unit 130.

Furthermore, when the target output voltage setting unit 160 inputs a vehicle speed V that is a driving condition parameter of the vehicle, the target output voltage VBPIG * is made variable according to the value.
As a result, in the twelfth embodiment, the target output voltage VBPIG * is lowered at the time of large output such as stationary driving and low-speed driving, so that heat generation in the coil L and the transistors Q1 and Q2 can be suppressed and loss is eliminated. , Can increase efficiency.

13. The thirteenth embodiment forms state then the thirteenth embodiment will be described with reference to FIG. 24.
In the thirteenth embodiment, a part of the eleventh embodiment is changed.

  The target output voltage setting unit 160 of the eleventh embodiment is configured by a two-dimensional map composed of the q-axis command current Iq * and the target output voltage VBPIG *. On the other hand, the target output voltage setting unit 160 of the present embodiment is different in that it is configured by a two-dimensional map composed of an angular velocity ω (motor angular velocity) and a target output voltage VBPIG *.

  That is, in the present embodiment, the target output voltage VBPIG * is made variable by the target output voltage setting unit 160 according to the angular velocity ω. Specifically, as shown in FIG. 24, the target output voltage setting unit 160 sets the target output voltage VBPIG * to be smaller in the region ω1 where the angular velocity ω is slow than in the regions ω2 and ω3 where the angular velocity ω is not. This map is stored in the ROM 22. Then, when the angular velocity ω is input, the CPU 21 uses this two-dimensional map to calculate the target output voltage VBPIG *.

Therefore, in the thirteenth embodiment, the following operation is performed.
The followability of the motor rotation speed becomes a problem whether or not current can be supplied to a winding (not shown) of the motor 6 when the motor 6 rotates at high speed. For this reason, the output voltage is increased in accordance with the motor angular velocity ω to improve the followability of the motor rotation speed.

  For this reason, it is not necessary to boost the region ω1 where the motor angular velocity ω is slow. Therefore, in this case, the boosting transistors Q1 and Q2 may be completely stopped. In this region ω1, the target output voltage VBPIG * is lowered. As a result, the booster circuit 100 stops boosting or lowers the boosting level below the regions ω2 and ω3.

In addition, the region ω3 where the motor angular velocity ω is high is a region that needs to be boosted.
For this reason, the booster circuit 100 boosts the voltage at a level higher than that of the region ω1. In the intermediate region ω2 between the region ω1 and the region ω3, the booster circuit 100 boosts the voltage so that the level is higher than the region ω1 and lower than the region ω3.

Control in the power running state and the regeneration state is similarly performed as shown in FIG. 22 of the eleventh embodiment.
Therefore, the thirteenth embodiment has the following effects.

(1) The same effects as (1) of the eleventh embodiment are achieved.
(2) In the thirteenth embodiment, the control device 20 (boost circuit control means) includes a target output voltage setting unit 160 (target output voltage setting means) for setting the target output voltage VBPIG * of the boost circuit 100, and a target output voltage. A PID control unit 120 that performs PID control calculation based on a deviation between VBPIG * and the output voltage VBPIG (at least a control calculation unit that performs P control), and performs a PWM calculation based on a calculation value of the PID control unit 120 to calculate a duty ratio The PWM calculation unit 130 (PWM calculation means) is included. The first and second switching elements Q1, Q2 are controlled to be turned on / off based on the duty ratio α calculated by the PWM calculation unit 130.

  Furthermore, when the motor angular speed ω, which is an operation status parameter of the motor 6, is input to the target output voltage setting unit 160, the target output voltage VBPIG * is made variable according to the value. As a result, in the thirteenth embodiment, the output voltage is increased in accordance with the motor angular velocity ω to improve the followability of the motor rotation speed. That is, by boosting the output voltage only when voltage is required, heat generation of the coil L and the transistors Q1 and Q2 can be suppressed as compared with the case of constantly boosting.

14 The fourteenth embodiment forms state then the fourteenth embodiment will be described with reference to FIG. 25.
The fourteenth embodiment is a modification of part of the eleventh embodiment.

  The target output voltage setting unit 160 of the eleventh embodiment is configured by a two-dimensional map composed of the q-axis command current Iq * and the target output voltage VBPIG *. On the other hand, the target output voltage setting unit 160 of the present embodiment is different in that it is configured by a two-dimensional map composed of the steering torque τ and the target output voltage VBPIG *.

  That is, in the present embodiment, the target output voltage VBPIG * is made variable by the target output voltage setting unit 160 according to the steering torque τ. Specifically, as shown in FIG. 25, the target output voltage setting unit 160 sets the target output voltage VBPIG * to be smaller in the region τ1 where the steering torque τ is small than in the regions τ2 and τ3 where the steering torque τ is not. This map is stored in the ROM 22. When the steering torque τ is input, the CPU 21 calculates the target output voltage VBPIG * by using this two-dimensional map.

Therefore, in the fourteenth embodiment, the following operation is performed.
The followability of the motor rotation speed becomes a problem when the motor 6 rotates at a high speed and the back electromotive force increases. In this case, since no current can be supplied to the motor 6, the assist force is reduced and the steering torque is increased.

For this reason, the steering torque τ is monitored, the output voltage is increased in accordance with the steering torque τ, and a current can be supplied to the motor 6 to improve the follow-up performance.
Specifically, the output voltage is increased according to the steering torque τ to improve the followability of the motor rotation speed.

  For this reason, it is not necessary to boost the region τ1 where the steering torque τ is small. Therefore, in this case, the boosting transistors Q1 and Q2 may be completely stopped. In this region τ1, the target output voltage VBPIG * is lowered. As a result, the booster circuit 100 stops boosting or lowers the boosting level below the regions τ2 and τ3.

Further, the region τ3 where the steering torque τ is large is a region that needs to be boosted.
For this reason, the booster circuit 100 boosts the voltage at a level higher than that of the region τ1. In the intermediate region τ2 between the region τ1 and the region τ3, the voltage is boosted by the booster circuit 100 so that the level is higher than the region τ1 and lower than the region τ.

Control in the power running state and the regeneration state is similarly performed as shown in FIG. 22 of the eleventh embodiment.
Accordingly, the fourteenth embodiment has the following effects.

(1) The same effects as (1) of the eleventh embodiment are achieved.
(2) In the fourteenth embodiment, the control device 20 (boost circuit control means) includes a target output voltage setting unit 160 (target output voltage setting means) for setting the target output voltage VBPIG * of the boost circuit 100, and a target output voltage. A PID control unit 120 (control calculation unit) that performs PID control calculation based on the deviation between VBPIG * and the output voltage VBPIG, and a PWM calculation unit 130 that performs PWM calculation based on the calculation value of the PID control unit 120 and calculates the duty ratio. (PWM calculation means). The first and second switching elements Q1, Q2 are controlled to be turned on / off based on the duty ratio α calculated by the PWM calculation unit 130.

Further, when the target output voltage setting unit 160 receives the steering torque τ, which is a vehicle driving condition parameter, the target output voltage VBPIG * is made variable according to the value.
As a result, in the fourteenth embodiment, the output voltage is increased according to the steering torque τ to improve the followability of the motor rotation speed. That is, by boosting the output voltage only when voltage is required, heat generation of the coil L and the transistors Q1 and Q2 can be suppressed as compared with the case of constantly boosting.

15. The fifteenth embodiment shaped state then the fifteenth embodiment will be described with reference to FIG. 26.
In the fifteenth embodiment, a part of the second embodiment is changed.

  In the present embodiment, the guard function unit 140 described in the sixth embodiment (see FIG. 14) is further provided in the configuration of the second embodiment. In the sixth embodiment, the guard function unit 140 performs the guard action only at the time of regeneration, but in this embodiment, the transistors Q1 and Q2 are turned on at the time of power running and regeneration as shown in FIG. 7 of the second embodiment. On / off control is performed, and the guard function unit 140 is activated during this control.

  In the guard function unit 140 according to the present embodiment, when the result of calculating the duty ratio α by the PWM calculation unit 130 exceeds α0 for some reason, α0 is determined as the duty ratio α.

  Therefore, in the fifteenth embodiment, when the duty ratio α calculated by the PWM calculation unit 130 exceeds α0 in both power running and regeneration, the guard function unit 140 sets α0. For this reason, the output voltage of the booster circuit 100 does not increase abnormally, and as a result, there is no possibility that the booster circuit 100 is damaged.

Accordingly, the fifteenth embodiment has the following effects in addition to the effects of the second embodiment.
(1) In the fifteenth embodiment, the control device 20 (boost circuit control means) includes a target output voltage setting unit 160 (target output voltage setting means) for setting a target output voltage VBPIG * of the boost circuit 100, and a target output voltage. A PID control unit 120 (control calculation unit) that performs PID control calculation based on the deviation between VBPIG * and the output voltage VBPIG, and a PWM calculation unit 130 that performs PWM calculation based on the calculation value of the PID control unit 120 and calculates the duty ratio. (PWM calculation means). The first and second switching elements Q1, Q2 are controlled to be turned on / off based on the duty ratio α calculated by the PWM calculation unit 130.

The control device 20 (boosting circuit control means) limits the duty so as not to perform PWM control exceeding α0 (predetermined duty ratio).
As a result, when the failure occurs in the RAM 23 or the output voltage VBPIG monitored for some reason is an abnormal value, the duty ratio α that is the calculation result of the PWM calculation unit 130 may increase. In this embodiment, in such a case, since the duty restriction is provided by the guard function unit 140, the booster circuit 100 can be prevented from being damaged both during power running and during regeneration.

Sixteenth to twenty-second embodiments Each of the first to fifteenth embodiments performs booster circuit control (hereinafter referred to as boost control) for powering and regeneration during execution of assist control. On the other hand, the sixteenth to twenty-second embodiments are control embodiments when a malfunction occurs in the booster circuit 100 itself during the boost control as described above.

  In the sixteenth to twenty-second embodiments, “normal boost control” in S30, which will be described later for convenience of description, will be described on the assumption that the boost control described in the second embodiment is performed, but is not limited thereto. It is not a thing. Of course, the following sixteenth to twenty-second embodiments can be realized on the premise of any boost control in the first to fifteenth embodiments.

16. The sixteenth embodiment forms state then a sixteenth embodiment will be described with reference to FIG. 27.
The sixteenth embodiment is different from the configuration of the fifteenth embodiment in that the control device 20 performs the control of FIG.

FIG. 27 is a routine for performing boost control and assist control of the boost circuit 100 executed by the CPU 21 of the control device 20. This control program is stored in the ROM 22 in advance.
In step (hereinafter, step is referred to as S) 10, it is determined whether or not the deviation (VBPIG * −VBPIG) between the target output voltage VBPIG * and the output voltage VBPIG is equal to or greater than the first reference value λ1 (> 0). The first reference value λ1 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like in order to determine an open failure or a short failure. In S10, it is determined whether or not the transistor Q1 has an open failure or the transistor Q2 has a short failure. That is, when the transistor Q1 has an open failure or when the transistor Q2 has a short-circuit failure, the output voltage VBPIG does not increase. Therefore, if the deviation exceeds the first reference value λ1, the transistor Q1 Open failure or short-circuit failure of the transistor Q2.

  When it is less than the first reference value λ1, it is normal rather than an open failure or short failure, so the time measurement counter Time1 is reset to 0 in S20, normal boost control and assist control are performed in S30, and the flow returns to S10.

  In the present embodiment, the determination value corresponds to (target output voltage VBPIG * −first reference value λ1). That is, the determination of whether or not the deviation (VBPIG * −VBPIG) ≧ first reference value λ1 in S10 is the same as determining (target output voltage VBPIG * −first reference value λ1) ≧ output voltage VBPIG. is there.

  Note that the normal boost control includes control during power running and regeneration. Specifically, the transistors Q1 and Q2 during power running and regeneration shown in FIG. 7 described in the second embodiment are used. Perform on / off control.

  If the first reference value λ1 is greater than or equal to the first reference value λ1 in S10, the time measurement counter Time1 is incremented in S40 as an open failure or a short failure, and whether or not the first predetermined time T1 has elapsed in S50 is set in the time measurement counter Time1. Judgment based on. If the open failure or the short failure has not passed the first predetermined time T1, it is determined that the booster circuit 100 is normal and the process returns to S10. The reason for determining the elapsed time in S50 is to eliminate an open failure or a short-circuit failure, which may happen, in some cases.

  In S50, when the first predetermined time T1 has elapsed, it is determined that the booster circuit 100 is abnormal, and the boost control is stopped in S60. Instead, the transistor Q1 is always turned off and the transistor Q2 is always turned on. Turn on. In this process, the transistor Q1 actually has an open fault or the transistor Q2 has a short fault. However, in the control, the transistor Q1 is actually turned off and the transistor Q2 is turned on.

  Even if the transistor Q1 has an open failure and the transistor Q2 is normal, the transistor Q2 is turned on so that a regenerative current flows to the battery B during regeneration.

  In S70, a warning signal (notification signal) is output to a warning lamp (not shown) provided on the instrument panel or the like to perform display control, and in S80, assist control is performed using the battery voltage (12V).

  That is, the boost control in the boost circuit 100 is stopped, but the assist control with the battery voltage is possible, so the assist control is executed under this voltage. Therefore, during regeneration, a regenerative current is passed through the battery B via the transistor Q2.

In the present embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit and a determination unit.
According to the sixteenth embodiment, there are the following effects in addition to the operational effects of the fifteenth embodiment.

  (1) In the sixteenth embodiment, the control device 20 is a state parameter detection means for detecting the output voltage VBPIG (state parameter) of the booster circuit 100, and the output voltage VBPIG and the determination value (target output voltage VBPIG * − The first reference value λ1) is compared to function as a determination unit that determines whether or not the booster circuit 100 is normal.

And the control apparatus 20 was made to stop the pressure | voltage rise control of the pressure | voltage rise circuit 100 as a pressure | voltage rise circuit control means according to the determined result (refer S60).
As a result, when the booster circuit 100 is out of order, the boost control of the booster circuit 100 can be stopped. As a result, it is possible to prevent the booster circuit 100 from being destroyed when the booster circuit 100 is abnormal.

  (2) In the present embodiment, when the booster circuit 100 is not normal, a warning light (notification means) is used for notification. As a result, the driver of the vehicle can be notified of the failure of the booster circuit 100.

  (3) In this embodiment, when the booster circuit 100 is not normal, especially when the difference between the target output voltage VBPIG * and the output voltage VBPIG is equal to or larger than the first reference value λ1, the transistor Q1 is open or the transistor Q2 is It was determined that there was a short failure (failure determination).

In this case, the transistor Q1 (first switching element) is always off-controlled and the transistor Q2 (second switching element) is always on-controlled.
As a result, although the assist control cannot be performed with the voltage boosted by the booster circuit 100, the assist control can be continuously performed with the battery voltage, and the regenerative current can be absorbed by the battery B during the regeneration.

(4) In this embodiment,
Output voltage VBPIG ≦ (target output voltage VBPIG * −first reference value λ1)
At this time, it can be determined that the transistor Q1 has an open failure or the transistor Q2 has a short failure.

  (5) In the sixteenth embodiment, the control device 20 (determination means) determines that an abnormality has occurred in the booster circuit 100 when the abnormal state continues for the first predetermined time T1. In the case of an abnormal state within the first predetermined time T1, since it is not determined to be abnormal, the case where the abnormal state is recovered within the first predetermined time T1 can be eliminated.

17. The seventeenth embodiment forms state seventeenth embodiment with reference to FIGS. 28 and 29 will be described.
In the present embodiment, a power relay 200 is provided at the connection point between the battery B, the application point P1, and the connection point as shown in FIG. 28 in addition to the hardware configuration of the sixteenth embodiment. The power relay 200 is turned on / off by a control signal from the control device 20. In the state where the control device 20 is activated, the power supply relay 200 is controlled to be in the on state by the control device 20.

  Further, a phase open relay 210 is provided between the connection point 83U of the FET 81U and FET 82U of the motor drive device 35 and the connection point of the U-phase winding of the motor 6. A phase open relay 220 is provided between the connection point 83W of the FET 81W and FET 82W of the motor drive device 35 and the connection point of the W-phase winding of the motor 6. The two-phase open relays 210 and 220 are turned on / off by a control signal from the control device 20. In the state where the control device 20 is activated, it is assumed that the two-phase open relays 210 and 220 are controlled to be on by the control device 20.

The power relay 200 corresponds to a first opening / closing means, and the application point P1 corresponds to a battery voltage supply unit. The phase opening relays 210 and 220 correspond to second opening / closing means.
In the present embodiment, during the control of the sixteenth embodiment, as shown in FIG. 29, the determination of S10A is performed instead of S10, and the processing of S90 and S100 is performed instead of S60 to S80. The place to end is different. Since the other steps are the same, the same step symbols are attached and the description thereof is omitted (the same steps in the following embodiments are also given the same reference numerals and the description thereof is omitted).

  In S10A, it is determined whether or not the deviation (VBPIG−VBPIG *) between the output voltage VBPIG and the target output voltage VBPIG * is greater than or equal to the second reference value λ2 (> 0). The second reference value λ2 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like in order to determine the open failure. In S10A, it is determined whether or not the transistor Q2 has an open failure. When the transistor Q2 has an open failure, the regenerative current does not flow to the battery B during regeneration, and the capacitor C2 cannot be discharged, so the output voltage VBPIG increases. Therefore, if there is a deviation greater than or equal to the second reference value λ2, it is determined that the transistor Q2 has an open failure.

When the deviation is less than the second reference value λ2, the process proceeds to S20. If the deviation is equal to or greater than the second reference value λ2, the process proceeds to S50 via S40.
In the present embodiment, the determination value corresponds to (second reference value λ2 + target output voltage VBPIG *). That is, the determination whether the deviation (VBPIG−VBPIG *) ≧ second reference value λ2 performed in S10A is the same as the determination of the output voltage VBPIG ≧ (second reference value λ2 + target output voltage VBPIG *). .

If it is determined in S50 that the predetermined time has elapsed, the process proceeds to S90.
In S90, an off control signal is applied to the phase open relays 210 and 220, both the phase open relays 210 and 220 are opened, and output of the duty ratio drive signal for boost control to the transistors Q1 and Q2 is stopped. At the same time, the control device 20 controls the power supply relay 200 to be turned off.

As a result, the booster circuit 100 and the two-phase (U-phase, W-phase) windings of the motor 6 are blocked from being supplied with power.
Thereafter, in S100, a warning signal (notification signal) is output to a warning lamp (not shown) provided on the instrument panel or the like to perform display control, and the control routine of FIG. 29 is terminated.

Also in this embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit and a determination unit.
In the seventeenth embodiment, the effect (5) of the sixteenth embodiment is obtained and the following effect is obtained.

  (1) In the present embodiment, the control device 20 includes state parameter detection means for detecting the output voltage VBPIG (state parameter) of the booster circuit 100, and the output voltage VBPIG and the determination value (second reference value λ2 + target). The output voltage VBPIG *) is compared to function as a determination unit that determines whether the booster circuit 100 is normal.

And the control apparatus 20 was made to stop the pressure | voltage rise control of the pressure | voltage rise circuit 100 as a pressure | voltage rise circuit control means according to the determined result (refer S90).
As a result, when the booster circuit 100 is out of order, the boost control of the booster circuit 100 can be stopped.

(2) Also, as in the sixteenth embodiment, when the booster circuit 100 is not normal, a warning lamp (notification means) is used for notification. As a result, the same effects as those in the sixteenth embodiment are obtained.
(3) Further, in the present embodiment, when the booster circuit 100 is not normal, especially when the deviation between the output voltage VBPIG and the target output voltage VBPIG * is equal to or larger than the second reference value λ2, the transistor Q2 has an open failure. It was determined that

  In this case, the power supply relay 200 (first opening / closing means) is operated to stop the power supply to the booster circuit 100. Further, an off control signal is applied to the phase open relays 210 and 220 (second opening / closing means) to open both phase open relays 210 and 220 and to cut off power supply to the two-phase windings related to the motor 6. .

  As a result, when the booster circuit 100 is out of order, the operation is shifted to manual steering so that the regenerative current does not flow to the booster circuit 100 even when the motor 6 is regenerating. Therefore, it is possible to prevent the circuit elements such as the capacitor C2 and the circuit elements of the motor driving device 35 that constitute the booster circuit 100 from being destroyed.

(4) In this embodiment,
Output voltage VBPIG ≧ (second reference value λ2 + target output voltage VBPIG *)
At this time, it can be determined that the transistor Q2 has an open failure.

18. The eighteenth embodiment shaped state eighteenth embodiment will be described with reference to FIG. 30.
The hardware configuration of the present embodiment is the same as the hardware configuration of the seventeenth embodiment.

  In the present embodiment, as shown in FIG. 30, a part of the routine of FIG. 27 (see FIG. 27) of the sixteenth embodiment and a part of the routine of the seventeenth embodiment (see FIG. 29) are combined. It has been made.

That is, a routine for performing boost control and assist control of the boost circuit 100 according to the eighteenth embodiment includes steps S10 to S50, S90, and S100.
Also in this embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit and a determination unit.

Accordingly, the eighteenth embodiment has the following effects.
(1) In this embodiment, since the configuration described in the sixteenth embodiment is provided, the same effects as (1), (2), (4), and (5) of the sixteenth embodiment are exhibited.

  (2) In the present embodiment, when the booster circuit 100 is not normal, particularly when the difference between the target output voltage VBPIG * and the output voltage VBPIG is equal to or greater than the first reference value λ1, the transistor Q1 is open or the transistor Q2 is Judged as short circuit failure.

In this case, the operation is the same as that in the seventeenth embodiment, and the power supply to the two-phase windings related to the booster circuit 100 and the motor 6 is cut off.
As a result, when the booster circuit 100 is out of order, the operation is shifted to manual steering so that the regenerative current does not flow to the booster circuit 100 even when the motor 6 is regenerating. Therefore, it is possible to prevent the circuit elements such as the capacitor C2 and the circuit elements of the motor driving device 35 that constitute the booster circuit 100 from being destroyed.

19. Figure 31 nineteenth preferred form status nineteenth embodiment will be described with reference to FIG. 32.
The hardware configuration of this embodiment has the same configuration as that of the seventeenth embodiment, and the drain of the transistor Q1 is connected to the voltage input port of the control device 20 so that the drain voltage VPIG2 of the transistor Q1 can be detected.

  The boost control and boost control routines of the boost circuit 100 according to the present embodiment are different in that the determination of S110 is performed instead of S10 of the routine of the eighteenth embodiment, as shown in FIG. Other steps are the same as those in the eighteenth embodiment.

  In S110, in order to determine whether or not the transistor Q1 is short-circuited, it is determined whether or not the input drain voltage VPIG2 is equal to or lower than a third reference value λ3 (determination value). Note that the third reference value λ3 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like and a value close to the ground potential in order to determine a short circuit failure. If it is determined in S110 that the drain voltage VPIG2 is equal to or lower than the third reference value λ3, it is determined that the transistor Q1 is short-circuited and the process proceeds to S40. On the other hand, if the drain voltage VPIG2 exceeds the third reference value λ3, it is determined that there is no short circuit failure, and the process proceeds to S20.

Also in this embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit and a determination unit.
Accordingly, the nineteenth embodiment has the following effects.

  (1) In the nineteenth embodiment, the control device 20 includes state parameter detection means for detecting the drain voltage VPIG2 of the transistor Q1, which is a state parameter of the booster circuit 100, and a third reference value, which is the drain voltage VPIG2 and a determination value. Compared with λ3, it functions as a determination means for determining whether or not the booster circuit 100 is normal.

And the control apparatus 20 was made to stop the pressure | voltage rise control of the pressure | voltage rise circuit 100 as a pressure | voltage rise circuit control means according to the determined result (refer S90).
As a result, when the booster circuit 100 is out of order, the boost control of the booster circuit 100 can be stopped.

(2) The same effects as (2) and (5) of the sixteenth embodiment are achieved.
(3) In the nineteenth embodiment, when the booster circuit 100 is not normal, particularly when it is determined that the drain voltage VPIG2 of the transistor Q1 is not more than the third reference value λ3, the transistor Q1 has a short circuit failure. It was determined. In this case, the operation is the same as in the seventeenth embodiment, and the power supply to the two-phase windings related to the booster circuit 100 and the motor 6 is cut off.

If the transistor Q1 is short-circuited, a short-circuit current flows from the battery B to the ground via the coil L, and there is a possibility that the circuit element in which the short-circuit current flows abnormally generates heat.
On the other hand, in this embodiment, since it comprised as mentioned above, generation | occurrence | production of the abnormal heat_generation | fever by a short circuit current can be prevented.

  Further, when the booster circuit 100 is out of order, the operation is shifted to manual steering so that the regenerative current does not flow to the booster circuit 100 even when the motor 6 is regenerating. Therefore, it is possible to prevent the circuit elements such as the capacitor C2 and the circuit elements of the motor driving device 35 that constitute the booster circuit 100 from being destroyed.

  (4) In the nineteenth embodiment, the control device 20 (state parameter detection means) detects the drain voltage VPIG2 of the transistor Q1 (first switching element) as the state parameter, and the control device 20 (determination means) When VPIG2 is equal to or smaller than the third reference value λ3 (determination value), it is determined that the booster circuit 100 is abnormal.

As a result, it can be determined that the transistor Q1 has a short circuit failure.
20. The twentieth embodiment forms state twentieth embodiment will be described with reference to FIG. 33.

The hardware configuration of this embodiment is the same as that of the seventeenth embodiment.
Then, the boost control of the booster circuit 100 of this embodiment and the routine for performing the assist control are different in that the determination of S120 is performed instead of S10 of the routine of the eighteenth embodiment, as shown in FIG. Other steps are the same as those in the eighteenth embodiment.

  In S120, in order to determine whether or not the transistor Q2 has an open failure, it is determined whether or not the input output voltage VBPIG is greater than or equal to the fourth reference value λ4 (determination value). The fourth reference value λ4 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like in order to determine an open failure. If it is determined in S120 that the output voltage VBPIG is greater than or equal to the fourth reference value λ4, it is determined that the transistor Q2 has an open failure, and the process proceeds to S40. If the output voltage VBPIG is less than the fourth reference value λ4, it is determined that there is no open failure, and the process proceeds to S20.

Also in this embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit and a determination unit.
Accordingly, the twentieth embodiment has the following effects.

  (1) In the present embodiment, the control device 20 compares the state parameter detection means for detecting the output voltage VBPIG (state parameter) of the booster circuit 100, and the output voltage VBPIG and the fourth reference value λ4 that is the determination value. Thus, it is made to function as a determination means for determining whether or not the booster circuit 100 is normal.

Then, the control device 20 stops the boost control of the booster circuit 100 according to the determined result as the booster circuit control means.
As a result, when the booster circuit 100 is out of order, the boost control of the booster circuit 100 can be stopped.

(2) The same effects as (2) and (5) of the sixteenth embodiment are achieved.
(3) In this embodiment, when the booster circuit 100 is not normal, particularly when it is determined that the drain voltage (output voltage VBPIG) of the transistor Q2 is equal to or higher than the fourth reference value λ4, the transistor Q2 is open It was determined that

In this case, the operation is the same as in the seventeenth embodiment, and the power supply to the two-phase windings related to the booster circuit 100 and the motor 6 is cut off.
As a result, when the booster circuit 100 is out of order, the operation is shifted to manual steering so that the regenerative current does not flow to the booster circuit 100 even when the motor 6 is regenerating. Therefore, it is possible to prevent the circuit elements such as the capacitor C2 and the circuit elements of the motor driving device 35 that constitute the booster circuit 100 from being destroyed.

  (4) In the twentieth embodiment, the control device 20 (state parameter detection means) detects the drain voltage (output voltage VBPIG) of the transistor Q2 (second switching element) as the state parameter, and the control device 20 (determination means). When the drain voltage (output voltage VBPIG) is equal to or higher than the fourth reference value λ4 (determination value), it is determined that the booster circuit 100 is abnormal.

As a result, it can be determined that the transistor Q2 has an open failure.
21. The first 21 embodiment shaped state twenty-first embodiment will be described with reference to FIG. 34.

The hardware configuration of this embodiment is the same as that of the seventeenth embodiment.
A routine for performing boost control and assist control of the booster circuit 100 according to the present embodiment is different from the routine according to the eighteenth embodiment in that the determination of S130 is performed instead of S10 of the routine of the eighteenth embodiment. Other steps are the same as those in the eighteenth embodiment.

  In S130, in order to determine whether or not the transistor Q2 has a ground fault between the circuits constituting the motor drive device 35, it is determined whether or not the input output voltage VBPIG is equal to or less than the fifth reference value λ5 (determination value). judge. Note that the fifth reference value λ5 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like to determine a ground fault and is close to the ground potential.

  If it is determined in S130 that the output voltage VBPIG is equal to or lower than the fifth reference value λ5, it is determined that the transistor Q2 has a ground fault, and the process proceeds to S40. If the output voltage VBPIG exceeds the fifth reference value λ5, it is determined that no ground fault has occurred, and the process proceeds to S20.

Also in this embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit and a determination unit.
Therefore, the twenty-first embodiment has the following effects.

  (1) In the present embodiment, the control device 20 compares the state parameter detection means for detecting the output voltage VBPIG (state parameter) of the booster circuit 100, and the output voltage VBPIG and the fifth reference value λ5 that is the determination value. Thus, it is made to function as a determination means for determining whether or not the booster circuit 100 is normal.

Then, the control device 20 stops the boost control of the booster circuit 100 according to the determined result as the booster circuit control means.
As a result, when the booster circuit 100 is out of order, the boost control of the booster circuit 100 can be stopped.

(2) The same effects as (2) and (5) of the sixteenth embodiment are achieved.
(3) In this embodiment, when the booster circuit 100 is not normal, especially when it is determined that the drain voltage (output voltage VBPIG) of the transistor Q2 is equal to or lower than the fifth reference value λ5, the transistor Q2 is grounded. It was determined that there was a failure.

In this case, the operation is the same as in the seventeenth embodiment, and the power supply to the two-phase windings related to the booster circuit 100 and the motor 6 is cut off.
As a result, when the booster circuit 100 is out of order, the operation is shifted to manual steering so that the regenerative current does not flow to the booster circuit 100 even when the motor 6 is regenerating. Therefore, it is possible to prevent the circuit elements such as the capacitor C2 and the circuit elements of the motor driving device 35 that constitute the booster circuit 100 from being destroyed.

  (4) In the twenty-first embodiment, the control device 20 (state parameter detection means) detects the drain voltage (output voltage VBPIG) of the transistor Q2 (second switching element) as the state parameter, and the control device 20 (determination means). When the drain voltage (output voltage VBPIG) is equal to or lower than the fifth reference value λ5 (determination value), it is determined that the booster circuit 100 is abnormal.

As a result, it can be determined that the transistor Q2 has a ground fault.
22-1. The 22nd embodiment shaped state 22nd embodiment with reference to FIGS. 35 and 36 will be described.

In the hardware configuration of this embodiment, a current detector 180 is further provided on the source side of the transistor Q1 as shown in FIG. 35 in addition to the hardware configuration of the seventeenth embodiment.
The current detector 180 detects the current I flowing through the transistor Q1, and inputs the detected signal (detection signal) to the current input port of the control device 20. The current detector 180 is provided on the source side of the transistor Q1, but may be connected to the drain side.

FIG. 36 is a routine for performing boost control and assist control of the boost circuit 100 executed by the CPU 21 of the control device 20.
When this control routine is started, in S200, the current I flowing through the transistor Q1 during power running is detected based on the detection signal detected by the current detector 180. In S210, the current I is compared with a first current reference value K1 that is a determination value. The first current reference value K1 is stored in advance in the ROM 22, and is a value obtained in advance through a test or the like in order to determine whether or not the transistor Q1 has a short circuit. When the transistor Q1 is short-circuited, a larger current flows than when the transistor Q1 is not, so it is determined by the first current reference value K1 whether or not this large current has flowed.

  If the current I is greater than or equal to the first current reference value K1, the time measurement counter Time2 is incremented in S220, assuming that the transistor Q1 has a short circuit failure, and whether or not the second predetermined time T2 has elapsed in S230 is determined as a time measurement counter. Determine based on Time2.

  If the short failure has not elapsed for the second predetermined time T2, it is determined that the booster circuit 100 is normal and the process returns to S200. The reason why the elapsed time is determined in S230 is to eliminate the short-circuit failure, which may occur by chance.

  When the second predetermined time T2 has elapsed, it is determined that the booster circuit 100 is abnormal, and in S240, a warning signal (notification signal) is output to a warning lamp (not shown) provided on the instrument panel or the like. Display control. Subsequently, in S250, an off control signal is applied to the phase open relays 210 and 220, both the phase open relays 210 and 220 are opened, and output of the duty ratio drive signal for boost control to the transistors Q1 and Q2 is stopped. To do. At the same time, the control device 20 controls the power supply relay 200 to be turned off. As a result, the booster circuit 100 and the two-phase (U-phase, W-phase) windings of the motor 6 are blocked from being supplied with power. That is, manual steering is achieved by stopping the power supply of the booster circuit 100 and the motor 6. After this processing, this control routine is terminated.

  In S210, when the current I is less than the first current reference value K1, it is determined that the transistor Q1 is not a short circuit failure, and then in S260, it is determined whether or not the current I is greater than or equal to the second current reference value K2. The second current reference value K2 (<K1) is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like in order to determine a short-circuit failure of the transistor Q2.

  When the transistor Q1 operates normally and the transistor Q2 is short-circuited during powering, a short-circuit current flows through the transistor Q2 at the moment when the transistor Q1 is turned on. When the transistor Q1 is turned off, the short circuit current of the transistor Q2 is cut off. At this time, when the transistor Q2 is short-circuited, the current flowing through the transistor Q1 (current when the transistor Q1 is on) is smaller than when the transistor Q1 is short-circuited. Therefore, the second current reference value K2 is smaller than the current value that flows when the transistor Q1 is short-circuited, and is a value that can determine the current that flows when the transistor Q2 is short-circuited.

  If the current I is greater than or equal to the second current reference value K2 in S260, it is determined that the transistor Q2 has a short circuit failure, and another time measurement counter Time3 different from S220 is incremented in S270. In next S280, it is determined based on the time measurement counter Time3 whether or not the third predetermined time T3 has elapsed.

  If the third predetermined time T3 has not elapsed since the short-circuit failure, it is determined that the booster circuit 100 is normal and the process returns to S200. The reason why the elapsed time is determined in S280 is to eliminate a short-circuit failure that may occur even if it happens.

  When the third predetermined time T3 has elapsed, it is determined that the booster circuit 100 is abnormal, and in S290, a warning signal (informing signal) is output to the warning lamp in the same manner as in S240 to perform display control. In step S300, manual steering is performed in the same manner as in step S250. After this processing, this control routine is terminated.

  In S260, when the current I is less than the second current reference value K2, both the transistors Q1 and Q2 are normal, not a short-circuit failure, so both time measurement counters Time2 and Time3 are reset to 0 in S310, and S320 Then, normal boost control and assist control are performed, and the process returns to S210.

  Also in the twenty-second embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a determination unit. Further, the control device 20 and the current detector 180 constitute state parameter detection means.

Accordingly, the twenty-second embodiment provides the following effects.
(1) In this embodiment, the control device 20 and the current detector 180 are used as the state parameter detection means for detecting the current (state parameter) flowing through the transistor Q1 which is the state parameter of the booster circuit 100. Further, the control device 20 functions as a determination unit that compares the current I with the first current reference value K1 and the second current reference value K2, which are determination values, to determine whether or not the booster circuit 100 is normal. (S210, S260).

And the control apparatus 20 was made to stop the pressure | voltage rise control of the pressure | voltage rise circuit 100 as a pressure | voltage rise circuit control means according to the determined result (S250, S300).
As a result, when the booster circuit 100 is out of order, the boost control of the booster circuit 100 can be stopped.

(2) The same effect as (2) of the sixteenth embodiment is obtained (see S240 and 290).
(3) In the twenty-second embodiment, when the booster circuit 100 is not normal, particularly when it is determined that the current I flowing through the transistor Q1 is equal to or higher than the first current reference value K1 that is a determination value, the transistor Q1 It was determined that a short circuit failure occurred (see S210). In this case, the operation is the same as in the seventeenth embodiment, and the power supply to the two-phase windings related to the booster circuit 100 and the motor 6 is cut off.

As a result, for the same reason as the effect (3) of the nineteenth embodiment, the effect described in (3) of the nineteenth embodiment can be achieved.
(4) In the twenty-second embodiment, when it is determined that the current I flowing through the transistor Q1 is less than the first current reference value K1, which is the determination value, and greater than or equal to the second current reference value K2, the transistor Q2 is short-circuited. It was determined that a failure occurred (see S260). In this case, the operation is the same as in the seventeenth embodiment, and the power supply to the two-phase windings related to the booster circuit 100 and the motor 6 is cut off.

As a result, the effects described in (3) of the nineteenth embodiment can be achieved as in (3) above.
(5) In the twenty-second embodiment, the power supply to the booster circuit 100 and the motor 6 (electric motor) is stopped after the second predetermined time T2 has elapsed in S230.

  As a result, it is possible to eliminate the case where the short-circuit failure of the transistor Q1 is recovered within the second predetermined time T2 or the case of erroneous determination, and the subsequent boost control and assist control can be suitably performed.

(6) In the twenty-second embodiment, the power supply to the booster circuit 100 and the motor 6 (electric motor) is stopped after the third predetermined time T3 has elapsed in S270.
As a result, it is possible to eliminate the case where the short-circuit failure of the transistor Q2 is recovered within the third predetermined time T3 or the case of the erroneous determination, and the subsequent boost control and assist control can be suitably performed.

  (7) In the twenty-second embodiment, the control device 20 and the current detector 180 (state parameter detection means) detect the current I flowing through the transistor Q1 (first switching element) as the state parameter, and the control device 20 (determination means). ) Compares the current I with the first current reference value K1 and the second current reference value K2 (determination value) to determine that the booster circuit 100 is abnormal. As a result, the abnormality of the transistors Q1 and Q2 can be determined.

22-2. Modified Example of 22nd Embodiment Next, a modified example of the 22nd embodiment will be described with reference to FIG .

  In this modification, the boosting control of the boosting circuit 100 executed by the CPU 21 of the control device 20 and a part of the routine for performing the assist control are different from the routine of the previous twenty-second embodiment. FIG. 37 shows a routine of the modified example.

As shown in FIG. 37, the processing of S330 and S340 is different from S300 in the control routine (see FIG. 36) described above.
In S330, the transistor Q1 is always turned off and the transistor Q2 is always turned on. That is, although the transistor Q2 is actually short-circuited, in the control, the transistor Q1 is turned off and the transistor Q2 is turned on.

  As a result, the boost control in the boost circuit 100 is stopped, but the assist control with the battery voltage (12 V in the present embodiment) is possible, so the assist control is executed under this voltage. Therefore, at the time of regeneration, a regenerative current can be supplied to the battery B via the transistor Q2.

  In this modified example, the effects (1) to (3) and (5) to (7) of the twenty-second embodiment are achieved, and when the transistor Q2 has a short circuit failure, assist control with the battery voltage can be performed.

23rd to 29th embodiments Each of the 16th to 22nd embodiments is an embodiment of control when a malfunction occurs in the booster circuit 100 during the boost control. In contrast, the 23-29 embodiment, when the ignition switch of the vehicle is turned on, performs initial check, it is determined whether there is abnormality in the booster circuit 100, the control in a case where there is an abnormality It is an embodiment.

In the twenty- third to twenty- ninth embodiments, the “boost control” in S520, which will be described later for convenience of explanation, will be described on the assumption that the boost control described in the second embodiment is performed, but is not limited thereto. It is not a thing. Of course, the 23rd to 29th embodiments can be realized on the premise of any boost control in the first to 15th embodiments.

23-1. The twenty third type state twenty-third embodiment will be described with reference to FIGS. 38 40.
In the first to twenty-second embodiments, the configuration and operation are not directly described because they are not directly related, but the vehicle is provided with an ignition switch IGS. Similarly, in the twenty-third embodiment, an ignition switch IGS is provided as shown in FIG. 38, and when the ignition switch IGS is turned on, power is supplied to the control device 20.

  The twenty-third embodiment differs from the nineteenth embodiment (see FIG. 31) in that the following configuration is added as shown in FIG. FIG. 39 is an electric circuit diagram of the booster circuit 100.

  The ignition circuit φ is adapted to apply an ignition voltage VIG when the ignition switch IGS is turned on. In the present embodiment, the ignition voltage VIG is the same voltage as the battery voltage. A resistor R1 is connected between a connection point P4 of the ignition circuit φ and a connection point P5 between the application point P1 and the coil L. The resistor R1 has a high resistance so that almost no current flows between the connection points P4 and P5. The pull-up circuit is configured by connecting the resistor R1 between the connection points P4 and P5.

  In the present embodiment, the control device 20 executes a control program including the initial check routine shown in FIG. 41 when the ignition switch IGS is turned on. This control program is stored in the ROM 22 in advance. Before ignition switch IGS is turned on, power supply relay 200 and phase open relays 210 and 220 are in an off state.

  When the ignition switch IGS is turned on, in S400, the CPU 21 checks the ROM 22 and RAM 23. When the ignition switch IGS is turned on, an ignition voltage VIG equal to the battery voltage is applied to the ignition circuit φ. Even if the power supply relay 200 is not turned on, the drain voltage VPIG2 of the booster circuit 100 is pulled up to the battery voltage.

  In S410, initialization of various registers such as an interface circuit (not shown) of the control device 20 and a special function register is performed. In S420, an all-on signal is output to the transistor Q1, and in S430, the drain voltage VPIG2 of the transistor Q1 is detected (read).

  In S440, it is determined whether or not the drain voltage VPIG2 of the transistor Q1 is equal to or higher than the sixth reference value λ6 (> 0). The sixth reference value λ6 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like in order to determine an open failure of the transistor Q1.

  That is, when the transistor Q1 is not open-failed, the transistor Q1 is turned on by the application of the all-on signal, so that the drain voltage VPIG2 of the transistor Q1 is lowered. Since this value is less than the sixth reference value λ6, it is determined that the transistor Q1 is not an open failure.

  On the other hand, when the transistor Q1 has an open failure, the transistor Q1 does not conduct even when the all-on signal is applied, so that the drain voltage VPIG2 of the transistor Q1 does not drop. Therefore, when the drain voltage VPIG2 is greater than or equal to the sixth reference value λ6, it is determined that the transistor Q1 has an open failure.

  If it is determined in S440 that there is no open failure, the process proceeds to S510. In step S510, the power supply relay 200 and the phase release relays 210 and 220 are turned on, and thereafter, step-up control and assist control are performed in step S520.

  On the other hand, if it is determined in S440 that there is an open failure, the time measurement counter Time4 is incremented in S450, and it is determined based on the time measurement counter Time4 whether or not a fourth predetermined time T4 has elapsed in S460.

  If the open failure has not passed the fourth predetermined time T4, it is determined that the booster circuit 100 is normal and the process returns to S430. The reason for determining the elapsed time in S460 is to eliminate an open failure that may be recovered even if it happens.

  In S460, when the fourth predetermined time T4 has elapsed, it is determined that the booster circuit 100 is abnormal, and in subsequent S470, a warning signal (notification signal) is sent to a warning lamp (not shown) provided on the instrument panel or the like. Output and control the display.

In subsequent S480, the transistor Q1 is always turned off and the transistor Q2 is always turned on.
In this process, the transistor Q1 actually has an open failure, but in the control, the transistor Q1 is actually turned off. In S480, the transistor Q2 is turned on so that the regenerative current flows to the battery B during regeneration.

In step S490, the power supply relay 200 and the phase opening relays 210 and 220 are turned on. In step S500, the boost control and assist control are performed in the same manner as in step S520.
That is, the boost control in the boost circuit 100 is stopped, but the assist control with the battery voltage is possible, so the assist control is executed under this battery voltage. Therefore, during regeneration, a regenerative current is passed through the battery B via the transistor Q2.

  In the present embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit, a first failure determination unit, and a first element control unit. The fifth reference value λ5 corresponds to the first failure determination value. The resistor R1 corresponds to the first resistor.

The power relay 200 corresponds to the first opening / closing means, and the phase opening relays 210 and 220 correspond to the second opening / closing means.
According to the twenty-third embodiment, the effects of the second embodiment are achieved, and the following effects are further obtained.

  (1) In the twenty-third embodiment, the power supply relay 200 (the first relay connected to the application point P1 (battery voltage supply unit) of the booster circuit 100 and on / off-controlled by the control device 20 (boost circuit controller). Opening and closing means are provided. Further, the pull-up circuit is connected to a connection point P5 between the drain of the transistor Q1 (first switching element) and the application point P1 via a resistor R1 (first resistor), and applies an ignition voltage VIG when the ignition switch IGS is turned on. An up circuit was provided.

  Then, the control device 20 controls the transistor Q1 as the first element control means before the power relay 200 is turned on when the ignition switch IGS is turned on. Further, the control device 20 functions as a drain voltage detection means for detecting the drain voltage VPIG2 of the transistor Q1 (first switching element) and compares the drain voltage VPIG2 with the fifth reference value λ5 (first failure determination value). Thus, it functions as first failure determination means for determining failure of the booster circuit 100.

As a result, the failure determination of the booster circuit 100 can be performed at the stage of the initial check after the ignition switch IGS is turned on.
(2) In the twenty-third embodiment, the phase opening relays 210 and 220 (second opening / closing means) for turning on and off the electric power of the motor 6 (electric motor) are provided.

  When the control device 20 determines that the booster circuit 100 has failed as the first failure determination means, the control device 20 (boost circuit control means) controls both the power supply relay 200 and the phase open relays 210 and 220 to be on (see S490). ). Further, the transistor Q1 (first switching element) is always turned off, and the transistor Q2 (second switching element) is always turned on (see S480).

  As a result, although the assist control cannot be performed with the voltage boosted by the booster circuit 100, the assist control can be executed with the battery voltage, and the regenerative current can be absorbed by the battery B during regeneration.

  (3) In the present embodiment, when the booster circuit 100 is not normal, a warning lamp (notification means) is used to notify (see S470). As a result, the driver of the vehicle can be notified of the failure of the booster circuit 100.

  (4) In the twenty-third embodiment, after the fourth predetermined time T4 has elapsed in S450, the process of S470 (warning lamp display) is performed. As a result, the case where the open failure of the transistor Q1 is recovered within the fourth predetermined time T4 can be eliminated.

  (5) In the twenty-third embodiment, the process of S480 is performed after the fourth predetermined time T4 has elapsed in S450. As a result, the case where the open failure of the transistor Q1 is recovered within the fourth predetermined time T4 can be eliminated.

23-2. Modified Example of 23rd Embodiment Next, a modified example of the 23rd embodiment will be described with reference to FIG.
FIG. 41 is a control flowchart processed by the CPU 21 in the modification.
In this modification, the hardware configuration is the same as that in the twenty-third embodiment, and the control routine is different as follows.

That is, in the flowchart shown in FIG. 40, the processing of S480 to S500 is omitted, and the control routine is ended after the processing of S470 is completed.
As a result, when there is an open failure in the transistor Q1, the power supply relay 200 and the phase open relays 210 and 220 are not turned on but are turned off.

The effects of this modification have the following effects in addition to the same effects as the effects (1), (3), and (4) of the twenty-third embodiment.
(1) In this modification, if it is assumed that the transistor Q1 has an open failure, the power supply relay 200 and the phase open relays 210 and 220 are not turned on but are turned off.

Therefore, when the transistor Q1 is open failure, that is, when the booster circuit 100 is failed, fail-safe can be applied.
24. 24th Embodiment shaped state 24th embodiment is the same as the hardware configuration of the twenty-third embodiment, also, the control is controlled and partially different as shown in FIG. 41 of the modified example of the twenty-third embodiment.

That is to say, as shown in FIG. 42, the processing of S420A instead of S420 and the processing of S440A instead of S440 are different.
In S420A, a full OFF signal is output to the transistor Q1.

  In S440A, it is determined whether or not the drain voltage VPIG2 of the transistor Q1 detected in S430 is equal to or lower than a seventh reference value λ7 (> 0). The seventh reference value λ7 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like in order to determine a short-circuit failure of the transistor Q1.

  That is, when the transistor Q1 is not short-circuited, the transistor Q1 is turned off by applying the all-off signal, so that the drain voltage VPIG2 of the transistor Q1 remains pulled up to the battery voltage.

Since this value exceeds the seventh reference value λ7, it is determined that the transistor Q1 is not a short circuit failure.
On the other hand, when the transistor Q1 has a short-circuit failure, the transistor Q1 is short-circuited even by the application of the all-off signal, so that the drain voltage VPIG2 of the transistor Q1 decreases and falls to the ground potential. Therefore, when the drain voltage VPIG2 is less than or equal to the seventh reference value λ7, it is determined that the transistor Q1 has a short circuit failure.

According to the twenty-fourth embodiment, in addition to the effects of the second embodiment and the effects (3) of the twenty-third embodiment, the following effects are achieved.
(1) In the twenty-fourth embodiment, the power supply relay 200 (the first relay connected to the application point P1 (battery voltage supply unit) of the booster circuit 100 and controlled to be turned on / off by the control device 20 (boost circuit controller). Opening and closing means are provided. Further, the pull-up circuit is connected to a connection point P5 between the drain of the transistor Q1 (first switching element) and the application point P1 via a resistor R1 (first resistor), and applies an ignition voltage VIG when the ignition switch IGS is turned on. An up circuit was provided.

  Then, the control device 20 controls the transistor Q1 to be turned off before the power supply relay 200 is turned on when the ignition switch IGS is turned on as the first element control means. Further, the control device 20 functions as a drain voltage detection means for detecting the drain voltage VPIG2 of the transistor Q1 (first switching element) and compares the drain voltage VPIG2 with the seventh reference value λ7 (first failure determination value). Thus, it functions as first failure determination means for determining failure of the booster circuit 100.

As a result, the failure determination of the booster circuit 100 can be performed at the stage of initial check after the ignition switch IGS is turned on.
(2) In the twenty-fourth embodiment, after the fourth predetermined time T4 has elapsed in S450, the warning lamp (informing means) is driven and controlled. As a result, the case where the short-circuit failure of the transistor Q1 is recovered within the fourth predetermined time T4 can be eliminated.

(3) In this embodiment, when it is assumed that there is a short circuit failure in the transistor Q1, the power supply relay 200 and the phase open relays 210 and 220 are not turned on but are controlled to be off.
Therefore, when the transistor Q1 has a short-circuit failure, that is, when the booster circuit 100 has failed, fail-safe can be applied.

25. 25th Embodiment shaped state diagram 43 is a control flowchart CPU21 processes in the first 25 embodiment.
The twenty-fifth embodiment is the same as the hardware configuration of the twenty-third embodiment, and the control is partially different from the control shown in FIG. 41 of the modification of the twenty-third embodiment.

That is, S420B is performed instead of S420, S430A is replaced instead of S430, and S440B is replaced instead of S440.
In S420B, the all-off signal is output to the transistor Q1, and at the same time, the all-on signal is output to the transistor Q2.

In S430A, the drain voltage V (output voltage VBPIG) of the transistor Q2 is detected.

In S440B, it is determined whether or not the drain voltage of the transistor Q2 detected in S430A, that is, the output voltage VBPIG is equal to or lower than an eighth reference value λ8 (> 0).
The eighth reference value λ8 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like in order to determine an open failure of the transistor Q2.

  In a state where the transistor Q1 is fully turned off, the drain voltage VPIG2 of the transistor Q1 remains pulled up to the battery voltage by the pull-up circuit. When the transistor Q2 is in a state in which an all-on signal is applied and the transistor Q2 is not open-failed, the drain voltage (output voltage VBPIG) of the transistor Q2 is also a battery voltage. Since this value exceeds the eighth reference value λ8, it is determined that the transistor Q2 is not an open failure.

  On the other hand, when the transistor Q2 has an open failure, the transistor Q2 has an open failure even when the all-on signal is applied, so that the drain voltage (output voltage VBPIG) of the transistor Q2 does not reach the battery voltage. Therefore, when the drain voltage (output voltage VBPIG) is equal to or lower than the eighth reference value λ8, it is determined that the transistor Q2 has an open failure.

According to the 25th embodiment, in addition to the effects of the second embodiment and the effects (3) and (4) of the 23rd embodiment, the following effects are exhibited.
(1) In the twenty-fifth embodiment, the power supply relay 200 (the first relay connected to the application point P1 (battery voltage supply unit) of the booster circuit 100 and controlled to be turned on / off by the control device 20 (boost circuit controller). Opening and closing means are provided. Further, the pull-up circuit is connected to a connection point P5 between the drain of the transistor Q1 (first switching element) and the application point P1 via a resistor R1 (first resistor), and applies an ignition voltage VIG when the ignition switch IGS is turned on. An up circuit was provided.

  Then, the control device 20 controls the transistor Q1 to be turned off and the transistor Q2 to be turned on before the power relay 200 is turned on when the ignition switch IGS is turned on as the first element control means.

  Further, the control device 20 functions as a drain voltage detecting means for detecting the drain voltage (output voltage VBPIG) of the transistor Q2 (second switching element), and also the drain voltage (output voltage VBPIG) and the eighth reference value λ8 (the eighth reference value). 1 failure determination value) and functions as first failure determination means for determining failure of the booster circuit 100.

As a result, the failure determination of the booster circuit 100 can be performed at the stage of initial check after the ignition switch IGS is turned on.
(2) In this embodiment, if there is an open failure in the transistor Q2, the power supply relay 200 and the phase open relays 210 and 220 are not turned on but are controlled to be off. Therefore, when the transistor Q2 has an open failure, that is, when the booster circuit 100 has failed, fail-safe can be applied.

26. The 26th embodiment shaped state 26 embodiment 44 is described with reference to FIG. 45.
In the twenty-sixth embodiment, the configuration of the twenty-third embodiment is partially changed and the control is changed.

  That is, the connection of the pull-up circuit in the twenty-third embodiment is different as shown in FIG. 44 in that it is connected to the connection point P6 with the drain of the transistor Q2. Note that the resistance R2 of the pull-up circuit in this embodiment is a high resistance that hardly causes a current to flow between the connection points P4 and P6.

  The twenty-sixth embodiment differs from the control routine of the twenty-third embodiment in that the process of S420B is performed instead of S420 and the process of S440A of the twenty-fourth embodiment is performed instead of S440.

In S420B, the all-off signal is output to the transistor Q1, and at the same time, the all-on signal is output to the transistor Q2.
In S440A, it is determined whether or not the drain voltage VPIG2 of the transistor Q1 detected in S430 is equal to or lower than a seventh reference value λ7 (> 0).

  When both transistors Q1 and Q2 are normal, the drain voltage VPIG2 of the transistor Q1 remains pulled up to the battery voltage by the pull-up circuit when the transistor Q1 is turned off and the transistor Q2 is turned on. That is, the drain voltage VPIG2 of the transistor Q1 is a battery voltage. Since this value exceeds the seventh reference value λ7, it is determined that the transistor Q1 is not a short circuit failure.

  On the other hand, when the transistor Q1 has a short circuit failure, the drain voltage VPIG2 of the transistor Q1 drops to the ground potential and does not reach the battery voltage. Therefore, when the drain voltage VPIG2 is less than or equal to the seventh reference value λ7, it is determined that the transistor Q1 has a short circuit failure.

  In the twenty-sixth embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit, a second failure determination unit, and a second element control unit. The seventh reference value λ7 corresponds to the second failure determination value. The resistor R2 corresponds to a second resistor.

The power relay 200 corresponds to the first opening / closing means, and the phase opening relays 210 and 220 correspond to the second opening / closing means.
According to the twenty-sixth embodiment, the effects of the second embodiment, the effects (3) and (4) of the twenty-third embodiment, the effects (2) and (3) of the twenty-fourth embodiment and the following effects are further achieved. There is.

  (1) In the twenty-sixth embodiment, the power supply relay 200 (the first relay connected to the application point P1 (battery voltage supply unit) of the booster circuit 100 and controlled to be turned on / off by the controller 20 (boost circuit controller). Opening and closing means are provided. In addition, a pull-up circuit is provided which is connected to the drain of the transistor Q2 (second switching element) via a resistor R2 (second resistor) and applies the ignition voltage VIG when the ignition switch IGS is turned on.

  Then, the control device 20 serves as the second element control means for both the transistor Q1 (first switching element) and the transistor Q2 (second switching element) before the power supply relay 200 is turned on when the ignition switch IGS is on. Are controlled to be turned off and on at the same time. Further, the control device 20 functions as a drain voltage detecting means for detecting the drain voltage VPIG2 of the transistor Q1 (first switching element) and compares the drain voltage VPIG2 with the seventh reference value λ7 (second failure determination value). Thus, it functions as second failure determination means for determining failure of the booster circuit 100.

As a result, the failure determination of the booster circuit 100 can be performed at the stage of initial check after the ignition switch IGS is turned on.
27-1. The twenty-seventh type state 27 embodiment will be described with reference to FIG. 46.

The twenty-seventh embodiment is the same as the configuration of the twenty-sixth embodiment, and the control is partially different.
That is, in the control routine shown in FIG. 45 of the twenty-sixth embodiment, the processing is different in that the processing of S420C is performed instead of S420B, and the processing of S440C is performed instead of S440A.

In S420C, all the off signals are simultaneously output to the transistors Q1 and Q2.
In S440C, it is determined whether or not the drain voltage VPIG2 of the transistor Q1 detected in S430 is equal to or lower than a ninth reference value λ9 (> 0). The ninth reference value λ9 is stored in advance in the ROM 22, and is a value obtained in advance by a test or the like in order to determine a short circuit failure of the transistor Q2.

  When both the transistors Q1 and Q2 are normal, the drain voltage (output voltage VBPIG) of the transistor Q2 is pulled up to the battery voltage by the pull-up circuit when the transistors Q1 and Q2 are all turned off.

That is, the drain voltage (output voltage VPIG2) of the transistor Q2 is the battery voltage.
At this time, since the transistor Q2 is turned off, the drain voltage VPIG2 of the transistor Q1 does not increase. Since this value exceeds the ninth reference value λ9, it is determined that the transistor Q2 is not a short circuit failure, and the process proceeds to S510.

  On the other hand, when the transistor Q2 has a short-circuit failure, the drain voltage VPIG2 of the transistor Q1 rises to the battery voltage. Therefore, when the drain voltage VPIG2 is greater than or equal to the ninth reference value λ9, the transistor Q2 has a short-circuit failure. It is determined.

  In the twenty-seventh embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit, a second failure determination unit, and a second element control unit. The ninth reference value λ9 corresponds to the second failure determination value. The resistor R2 corresponds to a second resistor.

The power relay 200 corresponds to the first opening / closing means, and the phase opening relays 210 and 220 correspond to the second opening / closing means.
According to the twenty-seventh embodiment, the effects of the second embodiment and the effect (3) of the twenty-third embodiment are exhibited and the following effects are further obtained.

  (1) In the twenty-seventh embodiment, the power supply relay 200 (the first relay connected to the application point P1 (battery voltage supply unit) of the booster circuit 100 and on / off-controlled by the control device 20 (boost circuit control means). Opening and closing means are provided. In addition, a pull-up circuit is provided which is connected to the drain of the transistor Q2 (second switching element) via a resistor R2 (second resistor) and applies the ignition voltage VIG when the ignition switch IGS is turned on.

  Then, the control device 20 serves as the second element control means for both the transistor Q1 (first switching element) and the transistor Q2 (second switching element) before the power supply relay 200 is turned on when the ignition switch IGS is on. Are controlled to be turned off at the same time. Further, the control device 20 functions as a drain voltage detecting means for detecting the drain voltage VPIG2 of the transistor Q1 (first switching element), and compares the drain voltage VPIG2 with the ninth reference value λ9 (second failure determination value). Thus, it functions as second failure determination means for determining failure of the booster circuit 100.

As a result, the failure determination of the booster circuit 100 can be performed at the stage of initial check after the ignition switch IGS is turned on.
(2) In the twenty-seventh embodiment, after the fourth predetermined time T4 has elapsed in S450, the warning lamp (informing means) is driven and controlled. As a result, the case where the short-circuit failure of the transistor Q2 is recovered within the fourth predetermined time T4 can be eliminated.

(3) In the twenty-seventh embodiment, phase open relays 210 and 220 (second opening / closing means) for turning on and off the electric power of the motor 6 (electric motor) are provided.
Further, when the control device 20 determines the failure of the booster circuit 100 as the second failure determination means, the control device 20 (boost circuit control means) controls both the power supply relay 200 and the phase open relays 210 and 220 to be on (see S490). ). Further, the transistor Q1 (first switching element) is always turned off, and the transistor Q2 (second switching element) is always turned on (see S480).

  As a result, although the assist control cannot be performed with the voltage boosted by the booster circuit 100, the assist control can be executed with the battery voltage, and the regenerative current can be absorbed by the battery B during regeneration.

27-2. Modified Example of 27th Embodiment FIG. 47 shows a modified example of the 23rd embodiment. The hardware configuration of this modification is the same as that of the twenty-seventh embodiment, and the control routine is different as follows.

That is, in the flowchart shown in FIG. 46, the processing of S480 to S500 is omitted, and the control routine is ended after the processing of S470 is completed.
As a result, when there is a short circuit failure in the transistor Q2, the power supply relay 200 and the phase open relays 210 and 220 are not turned on but are turned off.

The effects of this modification are as follows, in addition to the effects of the second embodiment, the effects of (3) of the twenty-third embodiment, and the same effects as the effects of (1) and (2) of the twenty-seventh embodiment. There is an effect.
(1) In this modification, if it is determined in S460 that the fourth predetermined time T4 has elapsed, that is, if there is an open failure in the transistor Q1, the power relay 200 and the phase open relays 210 and 220 are It is not turned on and is controlled off.

Therefore, when the transistor Q2 has a short circuit failure, a fail safe can be applied.
28. Twenty eighth type state diagram 48 is a control flowchart CPU21 processes the 28th embodiment.
The hardware configuration of this embodiment is the same as that of the 27th embodiment, and the control routine is different as follows.

That is, instead of S420C, S430, and S440C in FIG. 46, the processes of S420D, 430B, and S440D are performed.
In S430B, all on signals are simultaneously output to both the transistor Q1 and the transistor Q2. In S430B, the drain voltage VPIG2 of the transistor Q1 and the drain voltage (output voltage VBPIG) of the transistor Q2 are detected.

  In S440D, whether or not the drain voltage VPIG2 is equal to or higher than the tenth reference value λ10 (> 0) and the drain voltage (output voltage VBPIG) satisfies the tenth reference value λ11 (> 0) or more. Determine whether.

The tenth reference value λ10 and the eleventh reference value λ11 are stored in advance in the ROM 22, and are values obtained in advance by a test or the like in order to determine an open failure of the transistor Q1.
When both transistors Q1 and Q2 are normal, the drain voltage (output voltage VBPIG) of the transistor Q2 is pulled up to the battery voltage by the pull-up circuit in the state where the transistors Q1 and Q2 are all turned on. Is the ground voltage.

Accordingly, when both voltages are less than the tenth reference value λ11 and less than the eleventh reference value λ11, respectively, the transistor Q1 does not have an open failure, and the process proceeds to S510.
On the other hand, when the transistor Q1 has an open failure, the drain voltage VPIG2 of the transistor Q1 and the drain voltage (output voltage VBPIG) of the transistor Q2 do not become the ground voltage. That is, since both voltages are equal to or greater than the tenth reference value λ11 and the eleventh reference value λ11, it is determined that the transistor Q1 has an open failure, and the process proceeds to S450.

  In the twenty-eighth embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit, a second failure determination unit, and a second element control unit. The tenth reference value λ10 and the eleventh reference value λ11 correspond to a second failure determination value. The resistor R2 corresponds to a second resistor.

The power relay 200 corresponds to the first opening / closing means, and the phase opening relays 210 and 220 correspond to the second opening / closing means.
According to the twenty-eighth embodiment, the effects of the second embodiment, the effects (3) to (5) of the twenty-third embodiment, and the effects (3) of the twenty-seventh embodiment are provided, and the following effects are further obtained.

  (1) In the twenty-eighth embodiment, the power supply relay 200 (the first relay connected to the application point P1 (battery voltage supply unit) of the booster circuit 100 and controlled to be turned on / off by the controller 20 (boost circuit controller). Opening and closing means are provided. In addition, a pull-up circuit is provided which is connected to the drain of the transistor Q2 (second switching element) via a resistor R2 (second resistor) and applies the ignition voltage VIG when the ignition switch IGS is turned on.

  Then, the control device 20 serves as the second element control means for both the transistor Q1 (first switching element) and the transistor Q2 (second switching element) before the power supply relay 200 is turned on when the ignition switch IGS is on. Are controlled to be turned on at the same time. Further, the control device 20 functions as a drain voltage detecting means for detecting the drain voltage VPIG2 of the transistor Q1 (first switching element) and the drain voltage (output voltage VBPIG) of the transistor Q2, and the drain voltage VPIG2 and the tenth reference value. As second failure determination means for determining failure of the booster circuit 100 by comparing λ10 (second failure determination value), drain voltage (output voltage VBPIG) and eleventh reference value λ11 (second failure determination value). Function.

As a result, the failure determination of the booster circuit 100 can be performed at the stage of initial check after the ignition switch IGS is turned on.
28-2. Modified Example of 28th Embodiment FIG. 49 shows a modified example of the 28th embodiment. The hardware configuration of this modification is the same as that of the twenty-eighth embodiment, and the control routine is different as follows.

That is, in the flowchart shown in FIG. 48, the processing of S480 to S500 is omitted, and the processing routine is ended after the processing of S470 is completed.
As a result, when there is a short circuit failure in the transistor Q2, the power supply relay 200 and the phase open relays 210 and 220 are not turned on but are turned off.

The effects of this modification are as follows, in addition to the effects of the second embodiment, the effects (3) and (4) of the 23rd embodiment, and the effects (1) of the 28th embodiment. There is an effect.
(1) In this modification, if it is determined in S460 that the fourth predetermined time T4 has elapsed, that is, if there is an open failure in the transistor Q1, the power relay 200 and the phase open relays 210 and 220 are It is not turned on and is controlled off.

Therefore, when the transistor Q2 has a short circuit failure, a fail safe can be applied.
29. 29th Embodiment The 29th embodiment form state is 28 and the same configuration as modification of the embodiment, control is partially different.

That is, as shown in FIG. 50, the processing routine of S440E is performed instead of S440D in the control routine shown in FIG. 49 of the 28th embodiment.
In S440E, whether the drain voltage VPIG2 is equal to or lower than the twelfth reference value λ12 (> 0) and the drain voltage (output voltage VBPIG) satisfies the condition equal to or higher than the thirteenth reference value λ13 (> 0). Determine whether.

The twelfth reference value λ12 and the thirteenth reference value λ13 are stored in advance in the ROM 22, and are values obtained in advance by a test or the like in order to determine an open failure of the transistor Q2.
When both the transistors Q1 and Q2 are normal, the drain voltage (output voltage VBPIG) of the transistor Q2 is pulled up to the battery voltage by the pull-up circuit in the state where the transistors Q1 and Q2 are all turned on. Voltage.

  Accordingly, since the drain voltage VPIG2 is not more than the twelfth reference value λ12 (> 0) and the drain voltage (output voltage VBPIG) does not satisfy the condition not less than the thirteenth reference value λ13 (> 0), the transistor Q2 It determines with it being normal and transfers to S510.

  On the other hand, when the transistor Q2 has an open failure, the drain voltage VPIG2 of the transistor Q1 falls to the ground voltage, and the drain voltage (output voltage VBPIG) of the transistor Q2 does not become the ground voltage but remains the battery voltage.

That is, since the drain voltage VPIG2 is equal to or lower than the twelfth reference value λ12 and equal to or higher than the thirteenth reference value λ13, it is determined that the transistor Q2 has an open failure, and the process proceeds to S450.
In the twenty-ninth embodiment, the control device 20 corresponds to each unit described in the second embodiment, and also corresponds to a state parameter detection unit, a second failure determination unit, and a second element control unit. The twelfth reference value λ12 and the thirteenth reference value λ13 correspond to a second failure determination value. The resistor R2 corresponds to a second resistor.

The power relay 200 corresponds to the first opening / closing means, and the phase opening relays 210 and 220 correspond to the second opening / closing means.
According to the twenty-ninth embodiment, the effect of the second embodiment, the effect (3) of the twenty-third embodiment, and the effect (1) of the modification of the twenty-eighth embodiment are provided, and the following effect is further obtained.

  (1) In the twenty-ninth embodiment, after the fourth predetermined time T4 has elapsed in S450, the warning lamp (informing means) is driven and controlled. As a result, the case where the open failure of the transistor Q2 is recovered within the fourth predetermined time T4 can be eliminated.

In addition, you may change embodiment of this invention as follows.
○ Instead of the embodiment using the steering torque τ and the vehicle speed V, the motor control signal may be determined only by the steering torque τ.

  In the seventh to ninth embodiments, the CPU 21 determines the load state of the motor 6 based on the steering torque τ. However, based on the q-axis command current Iq * (motor control signal) set by the command current setting unit 54, You may determine whether the load state of the motor 6 is low load or high load.

In this case, the control device 20 as the load state determination unit performs load determination of the motor 6 (motor) based on the q-axis command current Iq * (motor control signal).
In the seventh to ninth embodiments, the motor 6 is a DC brushless motor, but may be a DC brush motor. In this case, the CPU 21 includes a known assist command current calculation unit and current control unit at the lower stage of the addition unit 53. Then, an assist command current value (motor control signal) is calculated based on the command torque τ * by the assist current calculation unit. The current control unit performs PWM calculation so that the motor current becomes the assist command current value, and drives the motor 6 via a known drive circuit that drives the brushed motor based on the calculation result. .

When driving such a motor with a brush, it may be determined whether the load state of the motor 6 is low or high based on the assist command current value.
In this case, the control device 20 as the load state determination means performs load determination of the motor 6 (electric motor) based on the assist command current value (motor control signal).

  In the first to fourteenth embodiments, the CPU 21 performs the PID control on the booster circuit 100 by the PID control unit 120. However, instead of this, a PI control unit may be provided to perform the PI control.

  The PI control unit performs proportional (P) / integral (I) processing to reduce the deviation between the target output voltage (20 V in this embodiment) and VBPIG input via the A / D converter 150, This circuit calculates the control amount of the transistors Q1 and Q2. The control amount calculated by the PI control unit is further converted into a duty ratio drive signal by calculating a duty ratio α corresponding to the control amount by the PWM calculation unit 130, and the converted duty ratio drive signal is converted into the boost circuit 100. Applied to the transistors Q1 and Q2.

  In the first to fourteenth embodiments, the CPU 21 performs PID control on the booster circuit 100 by the PID control unit 120. However, instead of this, a PD control unit may be provided to perform PD control.

  The PD control unit performs a proportional (P) / differential (D) process to reduce the deviation between the target output voltage (20 V in this embodiment) and VBPIG input via the A / D converter 150, This circuit calculates the control amount of the transistors Q1 and Q2. The control amount calculated by the PD control unit is further converted into a duty ratio drive signal by calculating a duty ratio α corresponding to the control amount by the PWM calculation unit 130, and the converted duty ratio drive signal is converted into the booster circuit 100. Applied to the transistors Q1 and Q2.

  In the sixth embodiment, the ninth embodiment, and the fifteenth embodiment, the duty is limited so that the PWM control of each switching element does not exceed the predetermined duty ratio and the PWM control is not performed. However, not only these embodiments but also other embodiments may similarly limit the duty. In this case, also in other embodiments, by providing the guard function unit 140 in the same manner, it is possible to limit the duty, and thus it is possible to prevent the booster circuit 100 from being damaged both during power running and during regeneration. .

  In the first to fourteenth embodiments, the CPU 21 performs PID control on the booster circuit 100 by the PID control unit 120. However, instead of this, a P control unit may be provided to perform P control.

  The P control unit performs a proportional (P) process to reduce the deviation between the target output voltage (20 V in this embodiment) and VBPIG input via the A / D conversion unit 150, and the transistors Q1, Q2 It is a circuit for calculating a control amount. The control amount calculated by the P control unit is further converted into a duty ratio drive signal by calculating a duty ratio α corresponding to the control amount by the PWM calculation unit 130, and the converted duty ratio drive signal is converted into the boost circuit 100. Applied to the transistors Q1 and Q2.

  In the sixteenth to 29th embodiments, when the booster circuit 100 is abnormal, the warning light is turned on with a warning signal. In addition to the warning light, a notification signal is output to a notification means such as a buzzer or a display. Then, a sounding action and a warning display may be displayed.

  In the 16th to 29th embodiments, when the booster circuit 100 is abnormal, the warning light is turned on with a warning signal after a predetermined time (first predetermined time T1 to fourth predetermined time) has elapsed. The warning lamp may be turned on immediately without elapse of time.

  In the 16 to 29 embodiments, after determination in each step (S10, S10A, S110, S120, S130, S210, and S260), after a predetermined time (first predetermined time T1 to fourth predetermined time) has elapsed, the booster circuit 100 Was abnormal.

  Instead of this, a warning lamp is turned on immediately after the abnormality is determined in each step without waiting for the elapse of a predetermined time (first predetermined time T1 to fourth predetermined time T4), or the booster circuit described in each embodiment You may make it perform the other required step at the time of 100 abnormality.

Next, technical ideas other than the invention described in the claims, which can be grasped from the embodiment and other examples, will be described below.
(1) operation status parameter, it characterized electrostatic power steering apparatus that the motor control signal is a driving condition parameter of the motor. In this case, the follow-up performance of the motor speed is not required at a large output such as stationary driving or low-speed traveling.In these cases, the target output voltage is set in a region where the motor control signal is large compared to the case where the output is not so. The heat generation in the boosting coil and the first and second switching elements can be suppressed, loss is eliminated, and the efficiency can be increased. The q-axis command current Iq * of the first embodiment corresponds to the motor control signal.

(2) operating conditions parameters to that electric power steering apparatus characterized in that the vehicle speed is driving condition parameters of the vehicle. In this way, the target output voltage is lowered at the time of large output such as stationary driving and low speed traveling, so that heat generation in the booster coil and the first and second switching elements can be suppressed, loss is eliminated, and efficiency is increased. Can do.

(3) driving situation parameter is the that electric power steering apparatus characterized in that it is a motor angular speed is the driving condition parameters of the electric motor. In this way, the output voltage is increased according to the motor angular speed to improve the followability of the motor rotational speed, and the output voltage is boosted only when the voltage is required, so that the boost coil, And the heat_generation | fever of a 1st, 2nd switching element can be suppressed.

(4) driving condition parameter, it characterized electrostatic power steering apparatus that the steering torque is a driving condition parameter of the vehicle. In this way, the output voltage is increased according to the steering torque to improve the followability of the motor rotation speed, and the output voltage is boosted only when the voltage is required, so that the boosting coil, And the heat_generation | fever of a 1st, 2nd switching element can be suppressed.

(5) The state parameter detection unit detects the output voltage of the booster circuit as the state parameter, and the determination unit determines that the booster circuit is abnormal when the output voltage is equal to or less than a determination value related to the target output voltage. It characterized electrostatic power steering apparatus. In this way, it can be determined that the first switching element has an open fault or the second switching element has a short fault.

Note that (target output voltage VBPIG * −first reference value λ1) in the sixteenth and eighteenth embodiments corresponds to a determination value related to the target output voltage.
(6) The state parameter detecting unit detects the output voltage of the booster circuit as the state parameter, and the determining unit determines that the booster circuit is abnormal when the output voltage is equal to or higher than a determination value related to the target output voltage. It characterized electrostatic power steering apparatus.

This makes it possible to determine that the second switching element has an open failure.
Note that (second reference value λ2 + target output voltage VBPIG *) in the seventeenth embodiment corresponds to a determination value related to the target output voltage.

(7) state parameter detecting means detects a drain voltage of the first switching element as a state parameter, determining means, when the drain voltage is greater than the judgment value, it wherein the boost circuit is judged to be abnormal electric power steering apparatus.

In this way, it can be determined that the first switching element is short-circuited.
In this case, the third reference value λ3 of the nineteenth embodiment corresponds to the determination value.
(8) state parameter detecting means detects a drain voltage of the second switching element as a state parameter, determining means, when the drain voltage is equal to or greater than the determination value, you wherein the boost circuit is judged to be abnormal electric power steering apparatus.

This makes it possible to determine that the second switching element has an open failure.
In this case, the fourth reference value λ4 of the twentieth embodiment corresponds to the determination value.
(9) a state parameter-detecting means detects the drain voltage of the second switching element as a state parameter, determining means, when the drain voltage is greater than the judgment value, it wherein the boost circuit is judged to be abnormal electric power steering apparatus.

In this way, it can be determined that the second switching element has a ground fault.
In this case, the fifth reference value λ5 of the twenty-first embodiment corresponds to the determination value.
(10) The state parameter detection means detects the current I flowing through the first switching element as the state parameter, and the determination means compares the current with a determination value and determines that the booster circuit is abnormal. be that electric power steering apparatus. In this way, it is possible to determine whether the first switching element or the second switching element is abnormal.

In this case, the first current reference value K1 and the second current reference value K2 of the twenty-first embodiment correspond to the determination values.
(11) The determination value includes a first current reference value K1 and a second current reference value K2 (<K1), and the determination means is configured such that when the current I is K2 ≦ I <K1, the second switching element is short-circuited. The electric power steering apparatus according to (10), wherein it is determined that there is a failure, and it is determined that the first switching element has a short-circuit failure when the current I is I ≧ K1. In this case, the abnormality of the first and second switching elements can be determined based on the magnitude relationship between the current flowing through the first switching element, the first current reference value K1, and the second current reference value K2.

(12) determination Priority determination means, when the abnormal state continues for a predetermined time, the electric power steering apparatus characterized by determining that an abnormality has occurred in the step-up circuit. In this way, in the case of an abnormal state within a predetermined time range, since it is not determined as an abnormality, the case where the abnormal state is recovered within the predetermined time can be eliminated.

In this case, the predetermined time corresponds to the first predetermined time T1 to the fourth predetermined time T4 in the sixteenth to twenty-ninth embodiments.
(13) before Symbol boosting circuit control means, when said determination means determines abnormal, the electric power steering apparatus characterized by outputting a notification signal. Thus, by outputting the notification signal, for example, a warning light, a buzzer, or the like can be driven, and the driver can be notified that an abnormality has occurred in the booster circuit.

1 is a schematic view of an electric power steering device embodied in an embodiment of the present invention. Similarly, a control block diagram of an electric power steering device. The control block diagram of CPU21 similarly. Similarly, the electric circuit diagram of the booster circuit. Similarly, a control block diagram of the control device during boosting. Similarly, the waveform diagram of the duty ratio drive signal of transistors Q1 and Q2. The wave form diagram of the duty ratio drive signal of transistor Q1, Q2 of 2nd Embodiment. The wave form diagram of the duty ratio drive signal of transistor Q1, Q2 of 3rd Embodiment. The wave form diagram of the duty ratio drive signal of transistor Q1, Q2 at the time of the power running state of 4th Embodiment. The wave form diagram of the duty ratio drive signal of transistor Q1, Q2 at the time of the regeneration state of 4th Embodiment. The electric circuit diagram of the booster circuit of 5th Embodiment. Similarly, the waveform diagram of the duty ratio drive signal of transistors Q1 and Q2 in the power running state. Similarly, the waveform diagram of the duty ratio drive signal of transistors Q1 and Q2 in the regenerative state. The control block diagram which shows the function performed with the control program at the time of regeneration in CPU of 6th Embodiment. Explanatory drawing which similarly shows the drive pattern of transistor Q1, Q2 in a regeneration state. Similarly, an equivalent circuit of the booster circuit in mode I. Similarly, an equivalent circuit of the booster circuit in mode I. Explanatory drawing which shows the drive pattern of transistor Q1, Q2 at the time of the power running state of 7th Embodiment. Explanatory drawing which similarly shows the drive pattern of transistor Q1, Q2 at the time of a power running state. The electric circuit diagram of the booster circuit of 10th Embodiment. The control block diagram of the control apparatus at the time of pressure | voltage rise of 11th Embodiment. The wave form diagram of the duty ratio drive signal of the transistors Q1 and Q2 of 11th Embodiment. The control block diagram of the control apparatus at the time of pressure | voltage rise of 12th Embodiment. The control block diagram which shows the function in CPU of 13th Embodiment. The control block diagram which shows the function in CPU of 14th Embodiment. The control block diagram which shows the function in CPU of 15th Embodiment. The control flowchart which CPU of 16th Embodiment processes. The control block diagram of the electric power steering device of 17th Embodiment. The control flowchart which CPU of 17th Embodiment processes. The control flowchart which CPU of 18th Embodiment processes. The electric circuit diagram of the booster circuit of 19th Embodiment. The control flowchart which CPU of 19th Embodiment processes. The control flowchart which CPU of 20th Embodiment processes. The control flowchart which CPU of 21st Embodiment processes. The electric circuit diagram of the booster circuit of the 22nd embodiment. The control flowchart which CPU processes similarly. The control flowchart which CPU processes in the modification of 22nd Embodiment. The control block diagram of the electric power steering device of a 23rd embodiment. The electric circuit diagram of the booster circuit of 23rd-25th embodiment. The control flowchart which CPU of a 23rd embodiment processes. The control flowchart which CPU processes in the modification of 23rd Embodiment. The control flowchart which CPU processes in 24th Embodiment. The control flowchart which CPU processes in 25th Embodiment. The electric circuit diagram of the booster circuit of 26th-29th embodiment. The control flowchart which CPU of 26th Embodiment processes. The control flowchart which CPU of 27th Embodiment processes. The control flowchart which CPU of the modification of 27th Embodiment processes. The control flowchart which CPU of a 28th embodiment processes. The control flowchart which CPU of the modification of 28th Embodiment processes. The control flowchart which CPU of 29th Embodiment processes. The circuit diagram of the conventional booster circuit. The waveform diagram which similarly shows the drive pulse waveform of transistor Q1.

Explanation of symbols

4 ... Torque sensor 6 ... Motor (electric motor)
20. Control device (control signal generating means, booster circuit control means, steering state determination means, load state determination means, state parameter detection means, determination means, first failure determination means, first element control means, drain voltage detection means, Second element control means, second failure determination means),
21 ... CPU
24 ... Pre-driver (Pre-driver means)
35 ... Motor drive device (motor drive means)
54 ... Command current setting section (especially corresponding to control signal generating means)
DESCRIPTION OF SYMBOLS 100 ... Booster circuit 120 ... PID control part (control calculation means)
130: PWM calculation unit (steering state determination means, PWM calculation means)
160... Target output voltage setting unit (target output voltage setting means)
200: Power relay (first opening / closing means)
210, 220 ... phase open relay (second opening / closing means)
B ... Battery, L ... Coil (Boosting coil)
C2: Capacitor (capacitor that smoothes the output voltage from the boosting coil)
C3: Capacitor (bootstrap capacitor)
Q1 ... transistor (first switching element)
Q2 ... Transistor (second switching element)
BS ... Bootstrap circuit

Claims (16)

At least determining the motor control signal based on a steering torque of the steering wheel, and a control signal generating means for outputting a same signal, and a motor driving means for driving the motor based on the motor control signal Rutotomoni,
A booster circuit is provided in a current supply circuit between the battery and the motor driving means,
The booster circuit is connected to a booster coil to which one end side is connected to a battery and a battery voltage is applied, a first switching element that grounds or opens the booster coil, and the other end side of the booster coil. A second switching element that is turned on and off, and a capacitor that is connected to the output side of the second switching element and smoothes a boosted voltage (hereinafter referred to as an output voltage) by the boosting coil,
Based on the deviation between the target output voltage and the output voltage, of the first and second switching elements, at the time of powering, at least the first switching element is turned on and off to boost the supply voltage of the motor, and at the time of regeneration, at least the electric power steering system which Ru and a boosting circuit control means for performing boost control to turn on and off the second switching element,
State parameter detecting means for detecting a state parameter of the booster circuit;
Determination means for comparing the state parameter detected by the state parameter detection means and a determination value to determine whether the booster circuit is normal;
The booster circuit control means stops boosting control of the booster circuit according to the result determined by the determination means, and when the determination means determines a failure, the first switching element is always controlled to be off and the second switching is performed. An electric power steering device characterized in that an element is always on-controlled. At least determining the motor control signal based on a steering torque of the steering wheel, and a control signal generating means for outputting a same signal, and a motor driving means for driving the motor based on the motor control signal Rutotomoni,
A booster circuit is provided in a current supply circuit between the battery and the motor driving means,
The booster circuit is connected to a booster coil to which one end side is connected to a battery and a battery voltage is applied, a first switching element that grounds or opens the booster coil, and the other end side of the booster coil. A second switching element that is turned on and off, and a capacitor that is connected to the output side of the second switching element and smoothes a boosted voltage (hereinafter referred to as an output voltage) by the boosting coil,
Based on the deviation between the target output voltage and the output voltage, of the first and second switching elements, at the time of powering, at least the first switching element is turned on and off to boost the supply voltage of the motor, and at the time of regeneration, at least the electric power steering system which Ru and a boosting circuit control means for performing boost control to turn on and off the second switching element,
The booster circuit control means includes target output voltage setting means for setting a target output voltage of the booster circuit, control calculation means for performing at least P control based on a deviation between the target output voltage and the output voltage, and the control calculation means PWM calculation means for performing a PWM calculation based on the calculation value and calculating a duty ratio, and for controlling the on / off of the first and second switching elements based on the duty ratio calculated by the PWM calculation means,
The target output voltage setting means inputs a driving condition parameter indicating a driving condition of the vehicle or the motor, makes the target output voltage variable according to the driving condition parameter,
A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
A circuit connected via a first resistor to a connection point between the drain of the first switching element and the battery voltage supply unit, and applying an ignition voltage when the ignition switch is turned on,
The booster circuit control means includes
First element control means for controlling on or off of at least the first switching element among the first switching element and the second switching element before the first opening / closing means is on-controlled when the ignition switch is on;
Drain voltage detection means for detecting the drain voltage of the first switching element or the second switching element;
1. An electric power steering apparatus comprising: a first failure determination unit that compares the drain voltage with a first failure determination value to determine a failure of the booster circuit . At least determining the motor control signal based on a steering torque of the steering wheel, and a control signal generating means for outputting a same signal, and a motor driving means for driving the motor based on the motor control signal Rutotomoni,
A booster circuit is provided in a current supply circuit between the battery and the motor driving means,
The booster circuit is connected to a booster coil to which one end side is connected to a battery and a battery voltage is applied, a first switching element that grounds or opens the booster coil, and the other end side of the booster coil. A second switching element that is turned on and off, and a capacitor that is connected to the output side of the second switching element and smoothes a boosted voltage (hereinafter referred to as an output voltage) by the boosting coil,
Based on the deviation between the target output voltage and the output voltage, of the first and second switching elements, at the time of powering, at least the first switching element is turned on and off to boost the supply voltage of the motor, and at the time of regeneration, at least the electric power steering system which Ru and a boosting circuit control means for performing boost control to turn on and off the second switching element,
The booster circuit control means includes target output voltage setting means for setting a target output voltage of the booster circuit, control calculation means for performing at least P control based on a deviation between the target output voltage and the output voltage, and the control calculation means PWM calculation means for performing a PWM calculation based on the calculation value and calculating a duty ratio, and for controlling the on / off of the first and second switching elements based on the duty ratio calculated by the PWM calculation means,
The booster circuit control means limits the duty so as not to perform PWM control exceeding a predetermined duty ratio,
A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
A circuit connected via a first resistor to a connection point between the drain of the first switching element and the battery voltage supply unit, and applying an ignition voltage when the ignition switch is turned on,
The booster circuit control means includes
First element control means for controlling on or off of at least the first switching element among the first switching element and the second switching element before the first opening / closing means is on-controlled when the ignition switch is on;
Drain voltage detection means for detecting the drain voltage of the first switching element or the second switching element;
1. An electric power steering apparatus comprising: a first failure determination unit that compares the drain voltage with a first failure determination value to determine a failure of the booster circuit . A control signal generating means for determining an electric motor control signal based on at least the steering torque of the steering wheel and outputting the signal; and an electric motor driving means for driving the electric motor based on the electric motor control signal;
A booster circuit is provided in a current supply circuit between the battery and the motor driving means,
The booster circuit is connected to a booster coil to which one end side is connected to a battery and a battery voltage is applied, a first switching element that grounds or opens the booster coil, and the other end side of the booster coil. A second switching element that is turned on and off, and a capacitor that is connected to the output side of the second switching element and smoothes a boosted voltage (hereinafter referred to as an output voltage) by the boosting coil,
Based on the deviation between the target output voltage and the output voltage, of the first and second switching elements, at the time of powering, at least the first switching element is turned on and off to boost the supply voltage of the motor, and at the time of regeneration, at least In an electric power steering apparatus comprising: boosting circuit control means for performing boosting control for turning on and off the second switching element;
State parameter detecting means for detecting a state parameter of the booster circuit;
Determination means for comparing the state parameter detected by the state parameter detection means and a determination value to determine whether the booster circuit is normal;
The booster circuit control means stops boosting control of the booster circuit according to the result determined by the determining means,
A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
A circuit connected via a first resistor to a connection point between the drain of the first switching element and the battery voltage supply unit, and applying an ignition voltage when the ignition switch is turned on,
The booster circuit control means includes
First element control means for controlling on or off of at least the first switching element among the first switching element and the second switching element before the first opening / closing means is on-controlled when the ignition switch is on;
Drain voltage detection means for detecting the drain voltage of the first switching element or the second switching element;
1. An electric power steering apparatus comprising: a first failure determination unit that compares the drain voltage with a first failure determination value to determine a failure of the booster circuit . A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
A second opening / closing means for turning on and off the electric power of the electric motor;
5. The electric power steering apparatus according to claim 4 , wherein when the determination unit makes a failure determination, the booster circuit control unit controls the first opening / closing unit and the second opening / closing unit to turn off . 5. The electric power steering apparatus according to claim 4 , wherein when the determination unit determines a failure, the first switching element is always turned off and the second switching element is always turned on . 6. A second opening / closing means for turning on and off the electric power of the electric motor;
The boost circuit control means controls the first opening and closing means and the second opening and closing means to be turned off when the first failure judging means makes a failure decision, according to any one of claims 2 to 6. The electric power steering apparatus as described. A second opening / closing means for turning on and off the electric power of the electric motor;
When the first failure determination means determines a failure, the booster circuit control means turns on both the first opening and closing means and the second opening and closing means,
The electric power steering apparatus according to any one of claims 2 to 6 , wherein the first switching element is always off-controlled and the second switching element is always on-controlled. A control signal generating means for determining an electric motor control signal based on at least the steering torque of the steering wheel and outputting the signal; and an electric motor driving means for driving the electric motor based on the electric motor control signal;
A booster circuit is provided in a current supply circuit between the battery and the motor driving means,
The booster circuit is connected to a booster coil to which one end side is connected to a battery and a battery voltage is applied, a first switching element that grounds or opens the booster coil, and the other end side of the booster coil. A second switching element that is turned on and off, and a capacitor that is connected to the output side of the second switching element and smoothes a boosted voltage (hereinafter referred to as an output voltage) by the boosting coil,
Based on the deviation between the target output voltage and the output voltage, of the first and second switching elements, at the time of powering, at least the first switching element is turned on and off to boost the supply voltage of the motor, and at the time of regeneration, at least In an electric power steering apparatus comprising: boosting circuit control means for performing boosting control for turning on and off the second switching element;
The booster circuit control means includes target output voltage setting means for setting a target output voltage of the booster circuit, control calculation means for performing at least P control based on a deviation between the target output voltage and the output voltage, and the control calculation means PWM calculation means for performing a PWM calculation based on the calculation value and calculating a duty ratio, and for controlling the on / off of the first and second switching elements based on the duty ratio calculated by the PWM calculation means,
The target output voltage setting means inputs a driving condition parameter indicating a driving condition of the vehicle or the motor, makes the target output voltage variable according to the driving condition parameter,
A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
A circuit connected to the drain of the second switching element via a second resistor and applying an ignition voltage when the ignition switch is turned on,
The booster circuit control means includes
When the ignition switch is turned on, before the first opening / closing means is turned on, both the first switching element and the second switching element are simultaneously turned on or off, or simultaneously turned off and turned on, respectively. Element control means;
Drain voltage detection means for detecting a drain voltage of at least the first switching element among the first switching element and the second switching element;
The drain voltage and is compared with the second failure determination value, the second failure for the failure determination of the step-up circuit determination means and to that electric power steering apparatus comprising the. A control signal generating means for determining an electric motor control signal based on at least the steering torque of the steering wheel and outputting the signal; and an electric motor driving means for driving the electric motor based on the electric motor control signal;
A booster circuit is provided in a current supply circuit between the battery and the motor driving means,
The booster circuit is connected to a booster coil to which one end side is connected to a battery and a battery voltage is applied, a first switching element that grounds or opens the booster coil, and the other end side of the booster coil. A second switching element that is turned on and off, and a capacitor that is connected to the output side of the second switching element and smoothes a boosted voltage (hereinafter referred to as an output voltage) by the boosting coil,
Based on the deviation between the target output voltage and the output voltage, of the first and second switching elements, at the time of powering, at least the first switching element is turned on and off to boost the supply voltage of the motor, and at the time of regeneration, at least In an electric power steering apparatus comprising: boosting circuit control means for performing boosting control for turning on and off the second switching element;
The booster circuit control means includes target output voltage setting means for setting a target output voltage of the booster circuit, control calculation means for performing at least P control based on a deviation between the target output voltage and the output voltage, and the control calculation means PWM calculation means for performing a PWM calculation based on the calculation value and calculating a duty ratio, and for controlling the on / off of the first and second switching elements based on the duty ratio calculated by the PWM calculation means,
The booster circuit control means limits the duty so as not to perform PWM control exceeding a predetermined duty ratio,
A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
A circuit connected to the drain of the second switching element via a second resistor and applying an ignition voltage when the ignition switch is turned on,
The booster circuit control means includes
When the ignition switch is turned on, before the first opening / closing means is turned on, both the first switching element and the second switching element are simultaneously turned on or off, or simultaneously turned off and turned on, respectively. Element control means;
Drain voltage detection means for detecting a drain voltage of at least the first switching element among the first switching element and the second switching element;
The drain voltage and is compared with the second failure determination value, the second failure for the failure determination of the step-up circuit determination means and to that electric power steering apparatus comprising the. A control signal generating means for determining an electric motor control signal based on at least the steering torque of the steering wheel and outputting the signal; and an electric motor driving means for driving the electric motor based on the electric motor control signal;
A booster circuit is provided in a current supply circuit between the battery and the motor driving means,
The booster circuit is connected to a booster coil to which one end side is connected to a battery and a battery voltage is applied, a first switching element that grounds or opens the booster coil, and the other end side of the booster coil. A second switching element that is turned on and off, and a capacitor that is connected to the output side of the second switching element and smoothes a boosted voltage (hereinafter referred to as an output voltage) by the boosting coil,
Based on the deviation between the target output voltage and the output voltage, of the first and second switching elements, at the time of powering, at least the first switching element is turned on and off to boost the supply voltage of the motor, and at the time of regeneration, at least In an electric power steering apparatus comprising: boosting circuit control means for performing boosting control for turning on and off the second switching element;
State parameter detecting means for detecting a state parameter of the booster circuit;
Determination means for comparing the state parameter detected by the state parameter detection means and a determination value to determine whether the booster circuit is normal;
The booster circuit control means stops boosting control of the booster circuit according to the result determined by the determining means,
A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
A circuit connected to the drain of the second switching element via a second resistor and applying an ignition voltage when the ignition switch is turned on,
The booster circuit control means includes
When the ignition switch is turned on, before the first opening / closing means is turned on, both the first switching element and the second switching element are simultaneously turned on or off, or simultaneously turned off and turned on, respectively. Element control means;
Drain voltage detection means for detecting a drain voltage of at least the first switching element among the first switching element and the second switching element;
The drain voltage and is compared with the second failure determination value, the second failure for the failure determination of the step-up circuit determination means and to that electric power steering apparatus comprising the. A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
  A second opening / closing means for turning on and off the electric power of the electric motor;
  12. The electric power steering apparatus according to claim 11, wherein when the determination means makes a failure determination, the booster circuit control means controls the first opening / closing means and the second opening / closing means to be turned off. 12. The electric power steering apparatus according to claim 11, wherein when the determination means determines a failure, the first switching element is always off-controlled and the second switching element is always on-controlled. A first opening / closing means connected to the battery voltage supply unit of the booster circuit and controlled to be turned on / off by the booster circuit control means;
  A circuit that is connected to the drain of the second switching element via a second resistor and applies an ignition voltage when the ignition switch is turned on,
  The booster circuit control means includes
  When the ignition switch is turned on, before the first opening / closing means is turned on, both the first switching element and the second switching element are simultaneously turned on or off, or simultaneously turned off and turned on, respectively. Element control means;
  Drain voltage detection means for detecting a drain voltage of at least the first switching element among the first switching element and the second switching element;
  9. The apparatus according to claim 2, further comprising: a second failure determination unit that compares the drain voltage with a second failure determination value to determine a failure of the booster circuit. The electric power steering apparatus as described. A second opening / closing means for turning on and off the electric power of the electric motor;
  The boosting circuit control means controls the first opening / closing means and the second opening / closing means to be turned off when the second failure determination means makes a failure determination. The electric power steering apparatus as described. A second opening / closing means for turning on and off the electric power of the electric motor;
  When the second failure determination means determines a failure, the booster circuit control means turns on both the first opening and closing means and the second opening and closing means,
  The electric power steering apparatus according to any one of claims 9 to 14, wherein the first switching element is always off-controlled and the second switching element is always on-controlled.

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