JP2008126864A - Controller for motor-driven vehicle and motor-driven vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a motor-driven vehicle for predicting slip of a front wheel in advance, and for controlling the vehicle to stabilize behavior of the vehicle before the slip occurs. <P>SOLUTION: The controller is used for the motor-driven vehicle which is provided with: a transmission 16 for transmitting the driving force of an engine 2 to front wheels 1R and 1L; a power generator 7 to be driven by the engine 2; and a motor 4 supplied with power generated by the power generator and for driving rear wheels 3R and 3L, and which travels either by two-wheel-drive or four-wheel-drive. The controller is provided with: an ATC/U 14 for controlling the transmission 16 to switch a gear ratio in transmitting the driving force from the engine 2 to the front wheels 1R and 1L; and a 4WD controller 8 for supplying the power generated by the power generator 7 to the motor 4 and outputting torque when the ATC/U 14 starts shift-down. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor-driven vehicle control device and a motor-driven vehicle, and more particularly to a motor-driven vehicle control device capable of switching between two-wheel drive traveling and four-wheel drive traveling and a motor drive equipped with the control device. Regarding vehicles.

  Currently, there is a motor-driven vehicle that travels on four wheels by generating electric power by rotating a generator with an engine and supplying the generated electric power directly to a motor. Some of these motor-driven vehicles travel while switching between two-wheel drive and four-wheel drive as necessary. As a prior art of a motor-driven vehicle capable of switching between two-wheel drive and four-wheel drive, for example, Patent Document 1 is cited.

The prior art described in Patent Document 1 detects the acceleration slip of the front wheel and controls the generator so as to output a torque corresponding to the slip amount. According to Patent Document 1 described above, when a slip occurs on the front wheel, the vehicle is automatically switched to four-wheel drive traveling, and torque is generated on the rear wheel to prevent the vehicle posture from becoming unstable. Can do.
JP 2004-215499 A

However, since the invention of Patent Document 1 controls the generator after it is detected that the front wheel actually slips, the behavior of the vehicle during the time from the control of the generator to the output of the rear wheel torque becomes unstable. It cannot be avoided.
The present invention has been made in view of the above points, and predicts a slip (idling) of a front wheel in advance, and controls a motor-driven vehicle control device that controls to stabilize the behavior of the vehicle before the slip occurs, and It aims at providing the motor drive vehicle provided with this control device.

  In order to solve the above problems, a motor-driven vehicle control device according to the present invention includes a transmission that transmits a driving force of an internal combustion engine to main drive wheels, a generator driven by the internal combustion engine, and the generator A motor-driven vehicle that includes a motor that is driven by electric power and drives the driven wheels and that travels by either two-wheel drive that drives only the main drive wheels or four-wheel drive that drives the slave drive wheels together with the main drive wheels And a gear ratio control means for controlling the transmission and switching a gear ratio when the driving force is transmitted from the internal combustion engine to the main drive wheel, and a shift down start by the gear ratio control means And motor torque control means for supplying the electric power generated by the generator to the motor and outputting torque.

  For this reason, in conjunction with the start of downshifting, the electric power generated by the generator 7 can be supplied to the motor 4 to output torque. According to the present invention as described above, electric power can be supplied to the motor 4 before the engine speed increases due to the downshift and excessive torque is generated in the front wheels. Therefore, it is possible to prevent the occurrence of slipping of the vehicle temporarily by generating torque on the rear wheel before the front wheel slips.

  According to the present invention, it is possible to predict the slip of the front wheel in advance and control the vehicle behavior to be stabilized before the slip occurs.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a motor-driven vehicle control device and a motor-driven vehicle according to the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a motor-driven vehicle control device (hereinafter also simply referred to as a control device) and a motor-driven vehicle including the control device according to an embodiment of the present invention. As illustrated, the motor-driven vehicle of the present embodiment includes a transmission 16 that transmits the driving force of the engine 2 to main driving wheels, an engine 2 that drives the main driving wheels, and a generator 7 that is driven by the engine 2. And a motor 4 that is driven by the power generated by the generator 7 and that drives the driven wheels. In the present embodiment, the main drive wheels are the front wheels 1L and 1R, and the slave drive wheels are the rear wheels 3L and 3R.

  The motor-driven vehicle can travel by either two-wheel drive that drives only the front wheels 1L and 1R, or four-wheel drive that drives the rear wheels 3L and 3R together with the front wheels 1L and 1R. Then, the transmission 16 is controlled and an automatic control unit (ATC / U) 14 for switching the transmission gear ratio when the driving force is transmitted from the engine 2 to the front wheels 1L, 1R is linked to the start of downshifting by the ATC / U14. 7 includes a 4WD controller 8 that supplies electric power generated by the motor 7 to the motor 4 to output torque.

In the above configuration, the ATC / U 14 functions as a gear ratio control unit. The ATC / U 14 and 4WD controller 8 function as motor torque control means.
The 4WD controller 8 is also a control device that comprehensively controls the configuration related to the four-wheel drive traveling of the vehicle. The motor-driven vehicle includes a traction control system (TCS) 15 in addition to the ATC / U 14 and the 4WD controller 8 as a control device.

  In the present embodiment, the transmission 16 is configured by combining a plurality of gears having different sizes, and the shift down is performed by switching to a gear having a smaller diameter. However, the present embodiment is not limited to a configuration in which a shift change is performed by switching gears, and can also be applied to a continuously variable automatic transmission using a belt, a chain, and a pulley without using a gear.

Wheel speed sensors 27FL, 27FR, 27RL, and 27RR are provided on the front wheels 1L and 1R and the rear wheels 3L and 3R. Each wheel speed sensor 27FL, 27FR, 27RL, 27RR outputs a pulse signal corresponding to the rotational speed of the corresponding front wheel 1L, 1R, rear wheel 3L, 3R to the 4WD controller 8 as a wheel speed detection value.
The 4WD controller 8 includes an arithmetic processing unit such as a microcomputer, and is connected to the wheel speed signals detected by the wheel speed sensors 27FL to 27RR, the output signals of the power generation voltage sensor 10 and the current sensor, and the motor 4. The output signal of the resolver and the accelerator opening corresponding to the amount of depression of an accelerator pedal (not shown) are input.

  Further, the ATC / U 14 inputs an accelerator opening signal and a shift switching (shift-up / shift-down) signal by a driver's operation, and notifies the 4WD controller 8 of the signal. This notification is executed by transmission / reception such as CAN communication. The 4WD controller 8 transmits a control signal to the transmission 16 via the ATC / U 14 based on the received signal, and executes gear switching.

  The 4WD controller 8 controls the generator 7 so that the motor 4 outputs torque in conjunction with the start of switching. The 4WD controller 8 supplies current to a field coil (not shown) of the generator 7, and the generator 7 generates power under the control of the 4WD controller 8. The generated electric power is supplied to the motor 4, and the motor 4 rotates in a magnetic field formed by a field coil (not shown) and outputs torque.

  In the above-described configuration, a main throttle valve and a sub throttle valve (not shown) are interposed in the intake pipe of the engine 2. The main throttle valve is a valve that adjusts and controls the throttle opening according to the amount of depression of the accelerator pedal. The sub-throttle valve is a valve that uses a step motor or the like as an actuator and whose opening is adjusted and controlled by a rotation angle corresponding to the number of steps of the actuator.

By adjusting the throttle opening of the sub-throttle valve to be less than or equal to the opening of the main throttle valve, the engine output torque can be reduced independently of the driver's operation of the accelerator pedal. That is, the driving force for suppressing the acceleration slip of the front wheels 1L, 1R by the engine 2 can be controlled by adjusting the opening of the sub-throttle valve.
The output torque Te of the engine 2 is transmitted to the left and right front wheels 1L and 1R through the transmission 16 and the reference gear 5. A part of the output torque Te of the engine 2 is transmitted to the generator 7 through the endless belt 6. The generator 7 rotates at a rotational speed Ng obtained by multiplying the rotational speed Ne of the engine 2 by the pulley ratio. The generator 7 becomes a load on the engine 2 in accordance with the field current Ifg adjusted by the 4WD controller 8, and generates power in accordance with the load torque.

The magnitude of the power generated by the generator 7 is determined by the magnitudes of the rotational speed Ng and the field current Ifg. The rotational speed Ng of the generator 7 can be calculated from the rotational speed Ne of the engine 2 based on the pulley ratio.
The electric power generated by the generator 7 can be supplied to the motor 4 via the inverter 9. The drive shaft of the motor 4 can be connected to the rear wheels 3L and 3R via the speed reducer 11 and the clutch 12. In addition, the motor 4 of this embodiment is an AC motor. Moreover, the code | symbol 13 in a figure shows a difference gear.

The motor-driven vehicle is provided with a relay that connects and disconnects the inverter 9 and the generator 7. In a state where this relay is connected, DC power supplied from the generator 7 via a rectifier (not shown) is converted into three-phase AC in the inverter 9 to drive the motor 4.
The motor-driven vehicle according to the present embodiment is provided with a generator voltage sensor 10 that detects a generated voltage and a generator current sensor (not shown) that detects a generated current that is an input current of the inverter 9. The detection signal is output to the 4WD controller 8. The 4WD controller 8 controls the generator 7 and the motor 4 by determining whether the voltage value detected by the generator voltage sensor 10 is normal or abnormal. Further, a resolver is connected to the drive shaft of the motor 4, and the magnetic pole position signal θ of the motor 4 is output.

The clutch 12 is, for example, a wet multi-plate clutch, and performs engagement and disengagement according to a command from the 4WD controller 8. The clutch 12 may be any of a wet multi-plate clutch, a powder clutch, and a pump type clutch.
Here, the normal operation of the 4WD controller 8 will be briefly described. The 4WD controller 8 calculates the motor torque command value Tt from the speed difference between the front wheels 1L, 1R and the rear wheels 3L, 3R calculated based on the wheel speed signals of the four wheels and the accelerator pedal opening signal. The calculated motor torque command value Tt is output as the final torque command value Tt of the motor 4 by the known rear wheel traction control control based on the rear wheel speeds Vrl and Vrr and the vehicle speed V.

The 4WD controller 8 performs known vector control from the torque command value Tt and the motor rotation speed Vm. And the motor 4 is controlled by outputting the switching control signal of a three-phase power element to the inverter 9 and controlling a three-phase alternating current. Then, the state of the clutch 12 is controlled, and the clutch 12 is brought into the connected state while the four-wheel drive state is determined.
Further, the 4WD controller 8 controls the power generation amount of the generator 7 by controlling the field current Ifg of the generator 7. That is, the 4WD controller 8 calculates the electric power Pm necessary for the motor 4 using the following equation based on the torque command value Tt and the motor rotation speed Vm.
Pm = Tt × Vm (1)

Further, the generator required power Pg to be output by the generator 7 is calculated using the following equation.
Pg = Pm / Иm (2)
Here, Иm is the motor efficiency. That is, the generator required power Pg must be output by the motor efficiency higher than the motor required power Pm. The required generator power Pg is limited by the generated power limit values PL1 and PL2 so that the generated power does not exceed the power determined according to the transmittable torque of the belt that drives the generator 7.

In the present embodiment, the 4WD controller 8 notifies the ATC / U 14 of the downshift after determining the downshift. The ATC / U 14 changes the gear to a gear with a smaller diameter in response to the downshift notification.
Due to the downshift, the front wheels 1L and 1R may slip due to excessive drive torque. For this reason, the 4WD controller 8 controls the generator 7 in conjunction with the downshift notification to the ATC / U 14 to cause the generator 7 to generate predetermined power and supply it to the motor 4.

After the control of the generator 7, the ATC / U 14 is notified from the 4WD controller 8 that the generator control has been completed. After receiving this notification, the ATC / U 14 transmits a control signal to the transmission 16 to switch gears and execute a downshift.
Here, the value of the electric power that the 4WD controller 8 causes the generator 7 to generate will be described. In the present embodiment, it is assumed that the 4WD controller 8 detects a power value that can be generated by the generator 7 at the time when the downshift signal is notified by the ATC / U 14. This value is calculated using the rotational speed of the engine 2 and the value of the field current.

  The 4WD controller 8 can set a predetermined value in advance as the necessary torque for preventing the front wheel slip, and can set the power value at which the necessary torque can be output as the above-described predetermined power value. Then, the predetermined power value is compared with the power value that can be generated by the generator 7, and the lower one is supplied from the generator 7 to the motor 4 by selecting low. Such a 4WD controller 8 functions as a select row means in this embodiment.

Moreover, this embodiment is not limited to the structure which sets a fixed electric power value as required torque. For example, the torque required to stabilize the vehicle when a front wheel slip occurs may be obtained by calculation.
The required torque can be calculated using at least one of the current rotational speed of the engine 2 and the torque increase value of the front wheels 1L and 1R accompanying the downshift. Even in such a case, the 4WD controller 8 selects low the electric power for outputting the necessary torque calculated by the calculation (denoted as necessary electric power) and the maximum electric power that can be generated by the generator 7 at the present time. , Choose a smaller power value. Then, the generator 7 is controlled, and the electric power of the selected electric power value is supplied from the generator 7 to the motor 4 to cause the motor 4 to output torque.

Further, in the present embodiment, it is conceivable that the required torque is set in advance according to the torque required when the vehicle starts. For example, when electric power is supplied to the motor 4 when the vehicle starts, this setting stores the electric power value in the 4WD controller 8. A predetermined power value can be determined based on the stored power value and set in advance.
Such an embodiment can be applied to an automatic (AT) vehicle even when the driver steps on the accelerator pedal to kick while traveling, so-called kick down. At this time, the 4WD controller 8 detects a kick-down operation by the driver and controls the motor 4 to output torque prior to gear switching.

  FIG. 2 is a flowchart for explaining torque control of the motor 4 performed by the above-described four-wheel drive control device of the present embodiment, and shows processing performed by the 4WD controller 8. As shown in FIG. 2, in the present embodiment, first, the ATC / U 14 notifies the 4WD controller 8 that a shift change will be made. The 4WD controller 8 detects the start of shift down by this notification (S21).

  When detecting the downshift, the 4WD controller 8 detects and confirms the power generation capability of the generator 7 (S22). Then, it is determined whether or not the generator 7 can generate electric power that allows the motor 4 to output a predetermined required torque (S23). The power generation capacity of the generator 7 can be confirmed not only by the voltage value detected by the generator voltage sensor 10 but also by the number of revolutions of the engine 2 and the generator 7.

In step S23, when the 4WD controller 8 determines that the required power can be generated (S23: Yes), the required power is supplied from the generator 7 to the motor 4, and the motor 4 outputs the required torque (S24). On the other hand, when it is determined in step S23 that the generator 7 cannot generate the required power (S23: No), the maximum power that can be generated by the generator 7 is supplied to the motor 4 to output torque (S25).
In addition, when a driver | operator requests a downshift, it is generally considered that the power generation capability of the generator 7 is low. For this reason, the maximum power that can be generated by the generator 7 is supplied to the motor 4 by Select Low. And it can relieve | moderate that the torque lower than a required torque is output and the vehicle by the front wheel slip becomes unstable.

  FIGS. 3A and 3B are diagrams comparing the case where the necessary torque is supplied to the motor 4 and the case where the maximum power that can be generated by the generator 7 is supplied to the motor 4. (A) shows the torque of the front wheels 1L, 1R (upper stage in FIG. 3 (a)) and the torque of the rear wheels 3L, 3R (lower stage in FIG. 3 (a)) when necessary power is supplied to the motor 4. ing. FIG. 3B shows the torques of the front wheels 1L and 1R (upper stage in FIG. 3B) and the torques of the rear wheels 3L and 3R when the maximum generated power of the generator 7 is supplied to the motor 4 (FIG. 3B). b) lower part).

  When the necessary power can be supplied, according to the present embodiment, as shown in FIG. 3A, the torque of the rear wheels 3L, 3R is generated almost simultaneously with the start of the shift change, and slips to the front wheels 1L, 1R. Has not occurred. When the maximum generated power of the generator 7 is supplied to the motor 4, as shown in FIG. 3 (b), the torque of the rear wheels 3L and 3R is generated almost simultaneously with the start of the shift change. It can be seen that slip is suppressed to 1L and 1R.

FIGS. 4A to 4F are diagrams for explaining the effects obtained by the embodiment described above. The horizontal axes of (a) to (f) all indicate time t, and are common to all of (a) to (f).
The vertical axis in FIG. 4A indicates the timing (time) at which a shift change is performed, and FIG. 4B indicates the shift position set in the vehicle at the present time. Further, (c) and (d) are examples of the prior art shown for comparison with the effects obtained in the present embodiment, where (c) is the driving torque of the front wheel and (d) is the rear wheel. Each of the driving torques is shown. Further, (e) shows the driving torque of the front wheels of this embodiment, and (f) shows the driving torque of the rear wheels.

  As shown in the figure, when a vehicle traveling in the second speed is shifted down to the first speed traveling, the ATC / U 14 estimates the occurrence of the shift down by the accelerator opening, the kick down, or the driver's operation. Then, the 4WD controller 8 is notified that a downshift occurs. The 4WD controller 8 receives this notification and starts an operation for downshifting at timing t1. At this time, the shift of the vehicle is set to the second speed traveling.

According to the prior art, as shown in (c), the shift change is executed after the start of the operation for downshifting, and the front wheel torque starts increasing at the timing t2. When a slip of the vehicle is detected due to an increase in front wheel torque, output of the rear wheel torque starts at timing t3 (d).
In contrast to such a conventional technique, in this embodiment, the generator 7 is controlled so that the 4WD controller 8 causes the motor 4 to output torque before the timing t2 in conjunction with the timing t1. Therefore, electric power is supplied from the generator 7 to the motor 4 prior to execution of the shift change at the timing t2, and torque is output to the rear wheels 3L and 3R at the timing t2 (e). Therefore, excessive torque is not generated on the front wheels 1L and 1R even by downshifting, and the vehicle can be prevented from slipping.

1 is a view showing a motor-driven vehicle control device according to an embodiment of the present invention and a motor-driven vehicle equipped with the control device. FIG. It is a flowchart for demonstrating the torque control of the motor performed by the four-wheel drive control apparatus of one Embodiment of this invention. In one Embodiment of this invention, it is the figure which compared and showed the case where required torque was supplied to the motor, and the case where the maximum electric power which a generator can produce | generate was supplied to the motor 4. FIG. It is a figure for demonstrating the effect acquired by one Embodiment of this invention.

Explanation of symbols

1L, 1R Front wheel 2 Engine 3L, 3R Rear wheel 4 Motor 7 Current generator 8 4WD controller 10 Generator voltage sensor 14 ATC / U
15 TCS
16 Transmission

Claims (5)

A transmission for transmitting the driving force of the internal combustion engine to the main driving wheel; a generator driven by the internal combustion engine; and a motor for supplying the power generated by the generator to drive the driven driving wheel. A control device for a motor-driven vehicle that travels by either two-wheel drive that drives only the vehicle, or four-wheel drive that drives the slave drive wheel together with the main drive wheel,
Gear ratio control means for controlling the transmission and switching a gear ratio when transmitting a driving force from the internal combustion engine to the main drive wheel;
In conjunction with the start of downshifting by the transmission ratio control means, motor torque control means for supplying electric power generated by the generator to the motor and outputting torque.
A motor-driven vehicle control device comprising: A select low means for selecting a smaller value from a predetermined power value determined in advance and the maximum power that the generator can generate at the present time;
2. The motor-driven vehicle control device according to claim 1, wherein the motor torque control unit supplies power of a value selected by the select low unit from the generator to the motor. 3.   The motor-driven vehicle control device according to claim 2, further comprising torque setting means for setting the predetermined power value determined in advance according to a torque required when the vehicle starts. A power value calculating means for calculating a power value using at least one of a rotational speed required for the internal combustion engine and a front wheel torque increase value associated with a downshift by the gear ratio control means;
Select low means for selecting a smaller value among the power value calculated by the power value calculating means and the maximum power that the generator can generate at the present time; and
4. The motor drive according to claim 1, wherein the motor torque control unit supplies the electric power of the value selected by the select low unit from the generator to the motor. 5. Vehicle control device. A transmission for transmitting the driving force of the internal combustion engine to the main driving wheel; a generator driven by the internal combustion engine; and a motor for supplying the power generated by the generator to drive the driven driving wheel. A motor-driven vehicle that travels by either two-wheel drive for driving only, or four-wheel drive for driving the slave drive wheel together with the main drive wheel,
Gear ratio control means for controlling the transmission and switching a gear ratio when transmitting a driving force from the internal combustion engine to the main drive wheel;
In conjunction with the start of downshifting by the transmission ratio control means, motor torque control means for supplying electric power generated by the generator to the motor and outputting torque.
A motor-driven vehicle comprising:

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