JP4371100B2 - Battery condition diagnostic device - Google Patents

Description

  The present invention relates to a battery state diagnosis apparatus that diagnoses the state of a battery that supplies power to a plurality of electric control systems provided in a vehicle.

  2. Description of the Related Art Conventionally, an electric power steering device is known as an example of an electric control system that is supplied with power from an in-vehicle battery. This electric power steering device is a device that applies a steering torque by controlling the amount of current supplied to the electric motor in accordance with the steering state of the steering wheel, but the power consumption is considerably high. For this reason, when the capacity of the battery is reduced (hereinafter referred to as deterioration), the amount of energization to the electric motor that generates the steering torque is limited and a predetermined steering torque cannot be obtained, or other electric power that operates simultaneously. The power supply voltage to the control system may be reduced.

Therefore, it is important to detect battery deterioration in advance before such a situation occurs and to prompt the driver to replace the battery.
As an apparatus for detecting deterioration of an in-vehicle battery, for example, in Patent Document 1, a predetermined amount from a battery between when a key switch for detecting insertion of a start key is turned on and when an ignition switch for engine start is turned on. A current is passed through the load, and the battery state is diagnosed from the change state of the battery voltage at that time.
JP 2000-190793 A

However, since the period from when the key switch is turned on to when the ignition switch is turned on is short, this makes it impossible to make a highly accurate diagnosis.
For this reason, the time for notifying the battery replacement is too early or too late to be an appropriate timing. In addition, when the battery diagnosis result is applied to the operation restriction of the electric power steering device, the amount of electric current supplied to the electric motor is excessively limited and sufficient steering torque cannot be obtained. Due to the lack of restrictions, the battery voltage dropped significantly, adversely affecting the operation of other electrical control systems.

  An object of the present invention is to cope with the above problem, and is to accurately diagnose the state of a battery.

In order to achieve the above object, a feature of the present invention is that a battery state diagnosis apparatus for diagnosing a state of a battery that supplies power to a plurality of electric control systems provided in a vehicle, wherein the plurality of electric controls are performed by turning off an ignition switch. Energization means for performing predetermined energization to a specific electrical control system among the plurality of electrical control systems after power supply to the system is stopped, and energization amount detection for detecting the amount of current flowing through the specific electrical control system Means, voltage fluctuation detecting means for detecting the voltage fluctuation state of the battery during the energization operation by the energization means, and a battery for diagnosing the state of the battery based on the detected energization amount and the voltage fluctuation state of the battery and a condition diagnosis means, said energizing means, gradually increasing the amount of current supplied to the specific electrical control system It lies in the fact.

According to the present invention configured as described above, after the power supply to various electric control systems is stopped by turning off the ignition switch, the specific electric control system is energized by the energizing means, Since the diagnosis of the battery status is performed based on the battery voltage fluctuation status, there is no adverse effect on the battery diagnosis due to the operation of other electric control systems, and a sufficient diagnosis time can be taken, so a highly accurate diagnosis result can be obtained. Obtainable.
In this case, for example, the energization means may energize an electric load such as an electric actuator of a specific electric control system after a predetermined period has elapsed since the ignition switch was turned off .

Moreover, since the energization amount to the electric control system is gradually increased, a problem that the battery voltage suddenly decreases is prevented. In other words, when the battery is considerably deteriorated, there is a concern that the battery voltage will drop suddenly by performing a predetermined energization, and the constantly energizing system of the vehicle will go down. Is prevented.

  Another feature of the present invention is that the specific electric control system provides an electric motor that applies a predetermined steering torque to the steered wheels, and an electric current flowing through the electric motor in accordance with an operation state of the steering wheel. It is an electric power steering apparatus provided with motor control means that detects and controls with a sensor.

In general, since the electric power steering apparatus includes a current sensor (energization amount detecting means) that detects an energization amount to the electric motor, the battery state can be diagnosed by effectively using the current sensor. Therefore, it is not necessary to newly provide a special current sensor, and the diagnosis of the battery state can be performed at a low cost.
In addition, since the electric power steering apparatus has a large amount of current supplied to the electric motor, a large current can flow even during battery diagnosis, and sufficient battery diagnosis can be performed. In other words, in order to perform battery diagnosis, it is necessary to draw a considerably large current from the battery. However, since the electric power steering apparatus originally operates by flowing a large current through the electric motor, it can be said to be an optimum load for battery diagnosis. .

  Another feature of the present invention is that the electric motor is a brushless DC motor, and the motor control means is the energization means, and the rotor of the brushless DC motor is made permanent during the battery status diagnosis. Only the d-axis armature current in the dq coordinate system consisting of the d-axis serving as the action axis of the magnetic flux generated by the magnet and the q-axis orthogonal to the d-axis is passed, and energization is performed so that the q-axis armature current does not flow. is there.

According to the present invention configured as described above, when diagnosing the battery state, only the armature current on the d axis in the dq coordinate system of the brushless DC motor is caused to flow by the motor control means, so that no rotational torque is generated. .
In general, the torque of a brushless DC motor constituting a permanent magnet synchronous motor is proportional to the product of the number of armature winding linkage magnetic fluxes and the q-axis armature current in the dq coordinate system, and the value of the d-axis armature current. Not affected by.

  Therefore, since the electric motor does not rotate at the time of battery diagnosis, no steering torque is generated and the steering handle does not rotate. As a result, the battery state can be safely diagnosed for the driver.

  Another feature of the present invention is that the motor control means intermittently energizes the electric motor. According to this, the power consumption of the battery can be suppressed.

  Another feature of the present invention is that the motor control means continuously energizes the electric motor. That is, the energization means gradually increases the energization amount to a predetermined current value by one energization. According to this, since the energization time becomes long, the chemical reaction in the battery is sufficiently performed, and the diagnostic accuracy of the battery is improved. In addition, the diagnostic accuracy is improved because it is close to the situation where the battery is actually used.

  Further, another feature of the present invention is provided with storage means for storing battery voltage fluctuation data at the time of battery condition diagnosis. The battery condition diagnosis means includes the stored past battery voltage fluctuation data and the current diagnosis time Is to diagnose the state of the battery based on the battery voltage fluctuation value.

According to this, the deterioration state suitable for the battery actually used can be diagnosed. In other words, since there are individual differences in battery characteristics, diagnosis based on a uniformly determined battery voltage fluctuation reference value is not preferable. Therefore, a diagnosis suitable for the battery can be made by comparing the past battery voltage fluctuation data of the battery being used with the battery voltage fluctuation value at the time of the current diagnosis.
For example, the highest value of the battery voltage detection value measured at the time of past diagnosis is stored as the voltage detection value of the initial state (for example, new) of the battery, and the voltage detection value of this initial state and the voltage detection value measured this time , It is possible to diagnose the current deterioration state with respect to the initial state of the battery.

According to another aspect of the present invention, there is provided an upper limit current value determining means for determining an upper limit current value that is allowed to energize the electric motor of the electric power steering device based on the diagnosed battery state. It is in.
According to this, since the upper limit current value is appropriately set by accurately diagnosing the battery state, it is possible to prevent the amount of energization to the electric motor from being excessively limited and to obtain an appropriate steering assist torque. On the other hand, it is possible to prevent a problem that the upper limit current value to the electric motor is set too high and the power supply amount to other electric control systems is excessively suppressed. As a result, the limited power of the battery can be distributed to each electric control system in a balanced manner.

Another feature of the present invention is that, when the elapsed time from the ignition switch off operation to the next on operation exceeds a predetermined time, the battery state diagnosis result performed up to the previous time is invalidated. It is in.
For example, when the vehicle has not been used for half a year, the state of the battery at the time of start-up has changed significantly from the state before half a year, so the battery voltage fluctuation data up to the previous time is ignored. Accordingly, it is possible to prevent the upper limit current value of the electric motor of the electric power steering apparatus from being limited.

Another feature of the present invention is that the pre-energization voltage detecting unit detects the battery voltage before energizing a specific electrical control system by the energizing unit, and the battery voltage before the energization is equal to or higher than a reference voltage. Only energization diagnosis permission means for allowing energization of the energization means and starting diagnosis of the battery state.
According to this, since it is possible to stop the diagnosis of a battery that is known to have deteriorated without being diagnosed, that is, a battery that does not satisfy the reference voltage before being energized, A problem that the remaining battery capacity is further reduced is prevented.

Another feature of the present invention is that the battery condition diagnosis means starts the diagnosis by energization of the energization means, and then energizes the energization means when the battery voltage falls below a predetermined voltage on the way. It is to stop and end the diagnosis.
According to this, when the battery voltage falls below a predetermined voltage during diagnosis, it is assumed that the battery state is bad, and no further energization is performed, so energization is continued and the remaining battery capacity is further reduced. Such a problem is prevented.

Another feature of the present invention is that the battery condition diagnosis unit starts diagnosis by energization of the energization unit, and then the battery voltage is equal to or higher than a predetermined voltage set according to the energization amount. Then, it is determined that the battery is in a good state, the energization of the energizing means is stopped, and the diagnosis is terminated.
According to this, after starting energization of the battery, if it is confirmed that the battery voltage is equal to or higher than a predetermined voltage set according to the energization amount, it is determined that the battery is in a good state at that time. Since the diagnosis is terminated, the battery is not energized more than necessary, and the power consumption of the battery for the diagnosis can be suppressed.

  Another feature of the present invention is that the motor control means confirms that the ignition key is removed based on a detection signal from a key detection means for detecting insertion / removal of the ignition key, and The purpose is to energize the electric motor of the power steering device.

  When the ignition key is removed, the steering wheel is locked, so even if power is supplied to the electric motor during battery diagnosis, the steering wheel does not rotate, and there is a person in the driver's seat. Is also safe. In addition, since the driver does not steer the steering wheel, regenerative power is not generated from the electric motor, and the battery diagnosis result is highly accurate.

  Hereinafter, an electric power steering apparatus including a battery state diagnosis apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows an electric power steering apparatus according to the embodiment.

  The electric power steering device 1 is roughly divided into a steering assist mechanism 10 that applies a steering assist force to the steered wheels, and an assist control device 30 that drives and controls the electric motor 15 of the steering assist mechanism 10.

  The steering assist mechanism 10 converts the rotation around the axis of the steering shaft 12 in conjunction with the turning operation of the steering handle 11 into the movement of the rack bar 14 in the axial direction by the rack and pinion mechanism 13. The left and right front wheels FW1 and FW2 that are steered wheels are steered in accordance with the movement in the direction. An electric motor 15 is assembled to the rack bar 14. The electric motor 15 applies assist force to the turning operation of the steering handle 11 by driving the rack bar 14 in the axial direction via the ball screw mechanism 16 according to the rotation. A rotation angle sensor 17 is attached to the electric motor 15, and a steering torque sensor 20 is assembled to the lower end portion of the steering shaft 12.

  The rotation angle sensor 17 is composed of a resolver, detects the rotation angle of the electric motor 15, and outputs a detection signal representing the detected rotation angle. The steering torque sensor 20 includes a torsion bar 21 that is interposed in the steering shaft 12 and has upper and lower ends connected to the steering shaft 12, and resolvers 22 and 23 that are assembled to the upper and lower ends of the torsion bar 21, respectively. . The resolvers 22 and 23 detect the rotation angles of the upper end and the lower end of the torsion bar 21 and output detection signals representing the detected rotation angles, respectively.

  The assist control device 30 includes an electronic control device 40 whose main part is constituted by a microcomputer, and a motor drive circuit 50 that drives and controls the electric motor 15 by a control signal from the electronic control device 40. Moreover, the electronic control unit 40 includes a battery diagnosis unit 41 and a motor control unit 42 in terms of its functions.

  The motor control unit 42 determines the energization amount to the electric motor 15 based on the detection signals from the rotation angle sensor 17, the steering torque sensor 20, and the vehicle speed sensor 28 that detects the vehicle speed, and controls the motor drive circuit 50. To generate a predetermined steering assist force. A motor temperature sensor 18 is connected to set an upper limit value of a d-axis armature current described later.

  On the other hand, the battery diagnosis unit 41 diagnoses the state of the battery 60 by energizing the electric motor 15 via the motor control unit 42, and detects opening / closing of the door in order to check the vehicle state as the diagnosis start condition. A door switch 81 for detecting the door lock, a key switch 83 for detecting the insertion / removal of the ignition key, and an alarm device 29 for notifying the driver of the diagnosis result are connected.

  As shown in FIG. 2, the motor drive circuit 50 constitutes a three-phase inverter circuit, and switching elements SW11, SW12, SW21, SW22, SW31, which correspond to the coils CLu, CLv, CLw of the electric motor 15, respectively. It has SW32. These switching elements SW11, SW12, SW21, SW22, SW31, and SW32 use MOSFETs in this embodiment, and are on / off controlled by a PWM control signal from the motor control unit 42. The motor drive circuit 50 is provided with current sensors 53a, 53b, and 53c for detecting the value of the current flowing through the electric motor 15 in each phase. Hereinafter, the three current sensors 53a, 53b, and 53c are collectively referred to as a current sensor 53.

Next, the electric motor 15 and the motor control unit 42 that controls driving of the electric motor 15 will be described in detail.
As the electric motor 15 of the present embodiment, a brushless DC motor constituted by a three-phase synchronous permanent magnet motor is used. The electric motor 15 includes a stator fixed in the housing, and forms a three-phase rotating magnetic field by flowing a three-phase current (armature current) through the coils CLu, CLv, and CLw wound around the stator. A rotor having a permanent magnet fixed in a phase magnetic field rotates in response to a three-phase current.

The motor control unit 42 controls three-phase currents that flow through the coils CLu, CLv, and CLw of the electric motor 15, and, as shown in FIG. 3, calculates and feeds back an assist current that inputs the vehicle speed v and the steering torque TR. An assist current command unit 42a for commanding the control unit 42c is provided.
The assist current command unit 42a calculates a two-phase command current (Id *, Iq *) corresponding to the assist torque that increases as the steering torque TR increases and decreases as the vehicle speed v increases.

The two-phase command currents (Id *, Iq *) are, as shown in the schematic diagram of FIG. 17, the d-axis and d-axis in the same direction as the magnetic flux generated by the permanent magnet MG on the rotor of the electric motor 15. Is an armature current in a dq coordinate system composed of a q-axis orthogonal to. That is, the two-phase command current (Id *, Iq *) is a command current composed of a d-axis armature current on the d-axis and a q-axis armature current on the q-axis in the dq coordinate system.
The torque of the brushless DC motor constituting the three-phase synchronous permanent magnet motor is proportional to the product of the number of armature winding interlinkage magnetic fluxes and the q-axis armature current in the dq coordinate system. Not affected by value. Accordingly, during assist control, an energization command is issued so that only the q-axis armature current that generates rotational torque flows, and the d-axis armature command current Id * is set to “0”.

  The motor control unit 42 includes a diagnostic current command unit 42b that commands the electric motor 15 to energize during battery state diagnostic control, which will be described later. In the battery state diagnosis control, as will be described later, a predetermined current is supplied to the electric motor 15 and the battery state is diagnosed based on the battery voltage at that time. The diagnosis is performed so that the electric motor 15 does not rotate at that time. In the current command unit 42b, the feedback control unit 42c is commanded using the two-phase command current (Id *, Iq *) so that only the d-axis armature current that does not generate rotational torque in the dq coordinate system is energized. Therefore, in this case, the q-axis armature command current Iq * is “0”.

In addition, when a d-axis armature current is passed, a magnetic flux in the opposite direction is applied to the permanent magnet provided in the rotor. Therefore, if a d-axis armature current is passed too much, the permanent magnet will be demagnetized. Moreover, the permanent magnet has a characteristic that it can be easily demagnetized at a high temperature or low sound depending on the kind of the magnetic material. For example, rare earth magnets such as neodymium are likely to be demagnetized on the high temperature side, and ferrite magnets are likely to be demagnetized on the low sound side.
Therefore, in the present embodiment, the diagnostic current command unit 42b takes in the detection signal of the motor temperature sensor 18 that detects the temperature of the electric motor 15, and sets the upper limit value of the d-axis armature current according to the detected temperature. For example, when a rare earth magnet that is easily demagnetized on the high temperature side is adopted as the permanent magnet, the d-axis armature current upper limit value Idmax is set according to the detected temperature as shown in FIG. When a ferrite magnet that is easily demagnetized is used, a d-axis armature current upper limit value Idmax is set according to the detected temperature, as shown in FIG.

  The motor temperature sensor 18 may be configured to detect the temperature of the housing of the electric motor 15 or the ambient temperature thereof, but may be detection based on estimation instead of such direct temperature detection. For example, using an existing temperature sensor such as an outside air temperature sensor that detects the outside air temperature, an intake air temperature sensor that detects the intake air temperature of the engine, or a substrate temperature sensor that detects the temperature of a circuit board (not shown) of the electronic control unit 40, the motor temperature It may be replaced with detection. Alternatively, the detected temperatures of the outside air temperature sensor, the intake air temperature sensor, and the substrate temperature sensor may be taken in, and the motor temperature may be estimated from a combination of these detected temperatures.

  Command signals from the assist current command unit 42a and the diagnostic current command unit 42b are output to the feedback control unit 42c. The feedback control unit 42c receives the detected values of the two-phase currents Id and Iq obtained by converting the detected values of the three-phase currents Iu, Iv and Iw flowing in the coils CLu, CLv and CLw of the electric motor 15 into a two-phase current. The The three-phase currents Iu, Iv, Iw flowing through the electric motor 15 are detected by the current sensor 53, and conversion from the three-phase currents Iu, Iv, Iw to the two-phase currents Id, Iq is performed by the three-phase / two-phase conversion unit 42f. Done.

For this three-phase / two-phase conversion, a rotation angle conversion unit 42g that converts the motor rotation angle detected by the rotation angle sensor 17 into an electrical angle is connected to the three-phase / two-phase conversion unit 42f.
The feedback control unit 42c performs two-phase command currents Id *, Iq * and two-phase detection currents Id, Iq in order to feedback control the three-phase currents Iu, Iv, Iw flowing through the coils CLu, CLv, CLw of the electric motor 15. Difference signals Id * -Id and Iq * -Iq are calculated.
The two-phase current difference signals Id * -Id and Iq * -Iq are converted into a three-phase signal by the two-phase / three-phase converter 42d and output to the PWM controller 42e. For the two-phase / three-phase conversion, the electrical angle signal from the rotation angle conversion unit 42g is input to the 2-phase / 3-phase conversion unit 42d.

The PWM controller 42e generates a pulse width modulation (PWM) control signal corresponding to the difference signals Id * -Id and Iq * -Iq based on the three-phase signal from the two-phase / three-phase converter 42d. Output to.
In this embodiment, the motor control unit 42 configured as described above is realized by executing a program of a microcomputer. The configuration shown in FIG. 3 represents each function in a block diagram. It is a thing.

Next, the configuration of the power supply line of the battery 60 will be described with reference to FIG.
The battery 60 used in this embodiment has a rated voltage of 12V.
An alternator 70 as a generator is connected to a power supply source line 62 connected to a power supply terminal (+ terminal) 61 of the battery 60, and the electric power steering apparatus 1 and other electric devices are connected via an ignition switch 80. A control system ES is connected.

The power supply line to the electric power steering apparatus 1 is a control power supply line 63 connected to the secondary side (load side) of the ignition switch 80 and a drive connected to the primary side (power side) of the ignition switch 80. And a power supply line 64.
The drive power supply line 64 is provided with a power supply relay 65, and a connection line 66 connecting the control power supply line 63 is provided on the load side of the power supply relay 65. The connection line 66 is provided with a diode 67 as a backflow prevention element that prevents current from flowing from the control power supply line 63 to the drive power supply line 64.
Further, the control power supply line 63 is provided with a diode 68 as a backflow prevention element for preventing the flow of current to the power supply side on the power supply side from the connection point with the connection line 66.

The control power supply line 63 is used for power supply to the electronic control unit 40, and the drive power supply line 64 is used for a power supply path to the motor drive circuit 50.
A power supply relay 65 provided in the drive power supply line 64 is opened and closed by a signal from the electronic control unit 40. The power supply relay 65 is turned on (closed) after the ignition switch 80 is turned on, and is described later after the ignition switch 80 is turned off. Turns off (opens) when the battery status diagnosis control routine is completed. The voltage of the drive power supply line 64 is monitored by the battery diagnosis unit 41 as a battery detection voltage.

Next, battery state diagnosis control executed by the electronic control unit 40 will be described.
4 to 7 show a battery state diagnosis control routine executed by the electronic control unit 40, and are stored in the ROM of the electronic control unit 40 as a control program.
As shown in FIG. 4, the battery state diagnosis control routine is roughly divided into a diagnosis start condition check routine (S1) for checking a diagnosis start condition of the battery 60, and a decrease in battery voltage by actually energizing the electric motor 15. A diagnosis motor energization routine (S5) for detecting the level and a battery state determination routine (S8) for determining the state of the battery 60 based on the battery voltage drop level.

First, a battery diagnosis start condition check routine will be described with reference to FIG.
FIG. 5 shows a diagnosis start condition check routine executed by the electronic control unit 40. The diagnosis start condition check routine is repeatedly executed at a predetermined short cycle. When the routine proceeds to the routine and it is determined that the battery has deteriorated and the diagnosis is finished, the routine is exited, and the routine proceeds to the battery state determination routine at step S8.

When this routine is activated, it is first determined whether or not the ignition switch 80 is turned off (S11). This determination is repeated until the ignition switch 80 is turned off. When an off operation of the ignition switch 80 is detected (S11: YES), it is determined whether or not the flag F is 0 (S13). This flag F is set to 0 when this routine is started, and is set to 1 when a predetermined time elapses after the ignition switch 80 is turned off, as will be described later.
Therefore, immediately after the ignition switch 80 is turned off, the determination in step S13 is “YES”, and the timer for measuring time is increased (S14). This timer measures the time from when the ignition switch 80 is turned off. When step S14 is performed for the first time, the timer is started.

Subsequently, it is determined whether or not the measurement by the timer has reached a predetermined time (S15), and this process is repeated until the predetermined time is reached.
When the predetermined time has elapsed, the determination in step S15 is “YES”, the timer is cleared to zero (S16), and the flag F is set to 1 (S17).
Thus, when a predetermined time elapses after the ignition switch 80 is turned off, the operation of each electric control system ES is stopped as shown in FIG. 8, and the amount of current flowing from the battery 60 is a very small amount (dark current). It becomes. That is, the predetermined time measured by the timer is set to be equivalent to the time required for each electric control system ES to stop.

  Subsequently, the process proceeds to step S18, where the battery detection voltage Vx is read, and the battery detection voltage Vx is compared with the lowest reference voltage Vmin0 (Vmin0 = 11V in this embodiment) (S18). If Vx <Vmin0 (S18: YES), it is determined that the battery 60 is in a deteriorated state without performing diagnosis of the battery 60 described later (S19), and a diagnosis end signal is output (S20). The process proceeds to the battery state determination routine in step S8.

On the other hand, when the battery voltage Vx is equal to or higher than the minimum reference voltage Vmin0 in step S18, the following three diagnosis start conditions are further checked.
That is, it is determined whether or not three conditions are satisfied: the ignition key is removed (S21), the vehicle door is opened and closed (S22), and the door is locked (S23). The determination in step S21 is a signal from the key switch 83 that is turned on / off in response to the insertion / removal of the ignition key, the determination in step S22 is a signal from the door switch 81 that is turned on / off in response to opening / closing of the door, and the determination in step S23 is a door lock. This is determined by reading the signal of the door lock switch 82 which is turned on / off according to the presence or absence.
When these three conditions are satisfied, it is estimated that the driver is getting out of the vehicle, and the diagnosis start permission of the battery state is permitted (S24), and the process proceeds to the diagnosis motor energization routine of step S5.

On the other hand, as long as these three conditions are not satisfied, the above-described processing is repeatedly executed without shifting to the next diagnosis motor energization processing. If the ignition switch 80 is turned on during the repetition process (S11: NO), the flag F is returned to 0 (S12). Thus, when the ignition switch 80 is turned off again, the above-described processing is repeated from the beginning.
Further, the time during which the three conditions of steps S21, S22, and S23 are not satisfied is measured (S25). If this condition is not satisfied even after a predetermined time has elapsed (S26: YES), this control routine is terminated.
The steps S18 and S24 correspond to the pre-energization voltage detection means and the energization diagnosis permission means of the present invention.

Next, the diagnostic motor energization control routine in step S5 will be described.
FIG. 6 shows a diagnostic motor energization control routine executed by the electronic control unit 40, and is repeatedly executed at a predetermined cycle.
First, it is determined whether or not the flag F is 1 (S51). When this control routine is started, the flag F is set to 1 in the above-described step S17, so that “YES” is always determined. As will be described later, this flag F is set to 1 before energization of the electric motor 15 is started, to 2 during energization, and to 3 when energization is stopped.

  Subsequently, a d-axis armature current upper limit value Idmax capable of energizing the electric motor 15 is a set current value Id3 described later (a d-axis armature current value obtained by converting the third energization current I3 shown in FIG. 9 into two phases). It is determined whether or not this is the case (S52). The d-axis armature current upper limit value Idmax is calculated from the temperature detected by the motor temperature sensor 18 with reference to the table shown in FIG. If Idmax ≧ Id3, the process proceeds to the energization process from the next step S53. On the other hand, if Idmax <Id3, the battery diagnosis motor energization control is terminated in order to avoid demagnetization of the permanent magnet of the electric motor 15.

If the determination in step S52 is “YES”, that is, if the d-axis armature current upper limit value Idmax is greater than or equal to the set current value Id3, the process proceeds to step S53, and energization of the first electric motor 15 is started. Note that “n” in step S53 is set to n = 1 at the start of diagnosis.
In the present embodiment, for example, as shown in FIG. In this case, the current flowing through the electric motor 15 is the two-phase detection current obtained by converting the two-phase command currents Id * and Iq * from the diagnostic current command unit 42b and the three-phase current detected by the current sensor 53 into a two-phase current. Based on the difference signals Id * -Id, Iq * -Iq representing deviations from Id, Iq, the PWM control unit 42e uses the pulse widths of the switching elements SW11, SW12, SW21, SW22, SW31, SW32 of the motor drive circuit 50. Is adjusted to a predetermined current value.

In this case, the motor control unit 42 flows only the d-axis armature current in the dq coordinate system and prevents the q-axis armature current from flowing so that the electric motor 15 does not rotate by energization.
Therefore, when the electric motor 15 is energized for battery diagnosis, since the electric motor 15 does not rotate, the steering handle 11 does not rotate, and it is safe even if a person is on the driver's seat.
Further, at each energization, the current value is gradually increased / decreased at the start and end of energization.
Even if the control is performed so that only the d-axis armature current flows, if the electric motor 15 rotates, it is preferable to stop the energization at that time and end the diagnosis of the battery state.

When energization of the first electric motor 15 is started in step S53, the flag F is subsequently set to 2 (S54).
Then, the energization timer for measuring the energization time is incremented (S55), and it is determined whether or not the energization timer has passed a predetermined time (S56). The energization of the electric motor 15 is continued until a predetermined time elapses, and it is determined whether or not the battery detection voltage Vx is lower than a predetermined voltage Vmin1 (Vmin1 = 9 V in the present embodiment) set in advance. However, if Vx <Vmin1, the battery 60 is in a deteriorated state, and it is determined that it is not preferable to continue the diagnosis by energization further because the battery 60 is further deteriorated, and the energization is stopped (S58, S59), the process goes to step S8.

On the other hand, if it is determined in step S57 that the battery detection voltage Vx is equal to or higher than the predetermined voltage Vmin1, it is further determined whether or not a battery diagnosis interruption condition is detected (S60). If the interruption condition is detected, the energization is stopped (S75), and this control routine is terminated. That is, when the ignition switch 80 is turned on, the key switch is inserted, the door is opened or closed, or the door lock is released, the control routine is executed while the control routine is being performed. finish.
If no interruption condition has occurred, the process returns to step S51 of this control routine. In this case, since the flag F is set to 2, the process proceeds from step S51 to step S55, and the energization timer is set. The same process is repeated until the energization for a predetermined time is completed.

Thus, when the energization timer expires after a lapse of a predetermined time from the start of energization (S56: YES), the energization timer is cleared to zero (S61), and it is determined whether or not the battery detection voltage Vx is higher than the normal reference voltage Vn0. (S62).
In this control routine, as will be understood from the processing described later, the energization of the electric motor 15 is divided into three times, so that the normal reference voltage Vn0 is set in advance according to the number of energizations (n-th). The value is set based on the good voltage drop characteristic of the battery 60.
If it is determined in step S61 that Vx> Vn0, it is determined that the state of the battery 60 is good at this point in time, energization is stopped (S63, S64), and the process returns to step S8.

On the other hand, if the detected voltage Vx of the battery is equal to or lower than the normal reference voltage Vn0 in step S62, the detected battery voltage Vx is stored in the nonvolatile memory in the electronic control unit 40 (S65), and the energization is stopped (S66).
Subsequently, the flag F is set to 3 (S67), and the stop timer is incremented (S68). This stop timer measures the elapsed time from the end of energization, and the flag F is set to 3 during this period. The determinations in steps S57 and S60 described above are repeated until the stop timer expires.

When the elapse of the predetermined time is thus measured by the stop timer, the stop timer is cleared to zero (S71), the flag F is set to 1 (S72), and the counter value n is incremented by 1 (S73). The counter value n represents the number of energizations, and the initial value is set to 1. Accordingly, the counter value is changed to 2 after one energization.
In step S74, it is determined whether or not the counter value n is 4, and the above-described processing is repeated until n = 4. That is, as shown in FIG. 9, a predetermined current is applied to the electric motor 15 three times (energization of only the d-axis armature current), and the battery detection voltage Vnx at each energization is stored.

In this case, the energization in step S53 is set such that the current value increases as the counter value n increases (I1 <I2 <I3). This is because, when a large current is suddenly supplied from the time of the first energization, depending on the state of the battery 60, the battery voltage may drop rapidly and the vehicle's constant energization system may go down. .
Moreover, the power consumption of the battery 60 can also be suppressed by energizing in multiple times. In this case, the energization time for one time is preferably within 1 second.

Further, in each energization period, the electric motor 15 should be increased by gradually increasing the current at the start of energization (see part A in FIG. 9) and gradually decreasing the current at the end of energization (see part B in FIG. 9). Even if rotational torque is generated, safety is taken into consideration so that the rotational operation does not become abrupt.
Further, when the battery state can be determined in the middle, that is, when the battery state is completely normal or extremely deteriorated, the energization is terminated at the time of the determination. No power consumption.
When the energization is completed three times by the above-described process, the process proceeds to the battery state determination process in step S8.

Here, a supplementary explanation will be given of the processing in step S52.
In this diagnostic motor energization control, a d-axis armature current in the dq coordinate system of the electric motor 15 is allowed to flow. However, if too much d-axis armature current is passed, a permanent magnet provided in the rotor. May demagnetize. Moreover, the permanent magnet has a characteristic that it can be easily demagnetized at a high temperature or low sound depending on the kind of the magnetic material. Therefore, the d-axis armature current upper limit value Idmax is set in the diagnostic current command unit 42b according to the motor detection temperature.
During the above-described diagnosis motor energization control, the d-axis armature current upper limit value Idmax set in accordance with the motor temperature is lowered, and the preset current value I3 at the time of the third energization is converted into two phases. If it is lower than the d-axis armature current value Id3 (S52: NO), there is a possibility that the permanent magnet may be demagnetized by energization for battery diagnosis. In other words, the power supply is stopped and the battery diagnosis motor power supply control is terminated.
As a result, it is possible to satisfactorily prevent demagnetization of the permanent magnet of the electric motor 15 at the time of diagnosis of the battery state.

Next, a battery state determination routine executed by the electronic control unit 40 will be described with reference to FIG.
When this routine starts, it is first determined whether or not the battery state has been determined (S81). That is, when it is determined that the battery state is good in step S63 described above, and when the battery state is determined to be bad in step S19 and step S58, it is determined that the battery state has been determined. Determines that it has not been determined.

If it has not been determined, the process proceeds to step S82. Here, it is determined whether or not the battery detection voltage V3x (battery detection voltage at the time of the third energization) stored in step S65 described above is higher than the maximum value V3i of the battery detection voltage V3x detected in the past. When the current battery detection voltage V3x is higher than the maximum value V3i of the battery detection voltage V3x detected in the past, the current battery detection voltage V3x is updated as the maximum value V3i of the battery detection voltage V3x detected in the past. Store (S83). That is, the battery voltage characteristics in the initial state of the battery 60 are stored. Hereinafter, the maximum value V3i is referred to as a battery voltage initial value V3i.
The battery detection voltage V3x and the battery voltage initial value V3i correspond to the battery voltage fluctuation data of the present invention.

Subsequently, in step S84, the deterioration degree D of the battery 60 is determined. In the present embodiment, a value obtained by subtracting the battery detection voltage V3x detected this time from the battery voltage initial value V3i is defined as a battery deterioration degree D (D = V3i−V3x).
In the present specification, the amount of electric power held by the battery 60 is reduced without specially distinguishing between the case where the battery 60 is deteriorated and the case where the charge rate of the battery 60 is reduced. The state in which the battery 60 is deteriorated is expressed, and the degree of deterioration D of the battery 60 is expressed as the amount of power held is small.

FIG. 10 shows voltage fluctuation characteristics according to the degree of deterioration D of the battery 60.
In this example, the voltage fluctuation characteristic L1 is in the initial state of the battery 60. The higher the deterioration degree D, the larger the voltage drop with respect to the increase in the energization current (the numerical value attached to the end of the symbol L attached in the figure). Degradation degree D is so high that is large).
Therefore, the deterioration state of the battery 60 can be accurately determined by comparing the battery detection voltage V3x at the time of the third energization through which the largest current flows with the battery voltage initial value V3i.

In the example shown in FIG. 10, in the battery having the voltage fluctuation characteristic L4, the battery detection voltage V2x falls below the predetermined voltage Vmin1 (9V) during the second energization, and in step S58 described above. Although it is determined that the deterioration is large and the diagnosis is terminated at this point and the battery detection voltage V3x is not measured, the deterioration degree D is set to the maximum value for such a case.
Further, in the case where it is determined in step S62 described above that the battery state is good, the deterioration degree D is set to the minimum value.

When the battery deterioration degree D is calculated in this way, next, an upper limit current value Iasmax of the assist current is determined based on the deterioration degree D (S85). The upper limit current value Iasmax of the assist current is set to a lower value as the deterioration degree D is higher as shown in the reference table of FIG. This reference table is stored in advance in the ROM of the electronic control unit 40.
The assist current is a current that is passed through the electric motor 15 to generate a predetermined steering torque. In the present embodiment, the assist current is determined from the steering torque TR and the vehicle speed v as shown in FIG.
Thus, when the upper limit value Iasmax of the assist current is determined, the battery state determination control routine ends.

  The diagnosis result of the battery state obtained in this control routine is not only reflected in the assist upper limit current value Iasmax, but may be notified to the driver from the indicator 29 at the start of the next operation. In this case, it is possible to replace the battery at an appropriate time by looking at the diagnosis result of the battery state, and not only can the steering assist function of the electric power steering device 1 be sufficiently obtained, but also various electric control systems ES It will always work well. Moreover, it is possible to prevent the electric control system from going down suddenly. Further, it is possible to prevent wasteful replacement of the battery before the battery has deteriorated.

In the diagnosis of the battery state, it is necessary to accurately detect the current value drawn from the battery 60. In this embodiment, the battery 60 is based on the current value detected by the current sensor 53 of the motor drive circuit 50. The current value drawn from is estimated.
For example, the battery 60 is obtained by summing the current value detected by the current sensor 53, the current component (known) used in the electronic control device 40, and the dark current component (known) used in another electrical control system ES. The current value drawn from can be estimated.

Next, assist control processing executed by the motor control unit 42 of the electronic control device 40 will be described.
FIG. 13 shows an assist control routine executed by the motor control unit 42, stored as a control program in the ROM of the electronic control unit 40, and repeatedly executed in a short cycle.

When this control routine is started by turning on the ignition switch 80, first, in step S101, the vehicle speed v detected by the vehicle speed sensor 28 and the difference between the rotation angles detected by the resolvers 22 and 23 of the steering torque sensor 20 are calculated. The steering torque TR is read.
Subsequently, referring to the assist current table shown in FIG. 12, the necessary assist current Ias corresponding to the input vehicle speed v and steering torque TR is calculated (S102). The assist current table is stored in the ROM of the electronic control unit 40, and as shown in FIG. 12, the required assist current Ias increases as the steering torque TR increases, and increases as the vehicle speed v decreases. Is set to be

Next, the assist upper limit current value Iasmax determined by the battery state diagnosis control routine described above is read (S103).
Subsequently, from the required assist current value Ias calculated in step S102 and the assist upper limit current value Iasmax read in step S103, the smaller current value is determined as the target assist current value to be passed through the electric motor 15 (S104). . Therefore, the target assist current value for energizing the electric motor 15 is the required assist current Ias if the required assist current value Ias is smaller than the upper limit current value Iasmax, and the upper limit current if the required assist current value Ias is larger than the upper limit current value Iasmax. The value is Iasmax.

  In this case, two-phase command currents Id * and Iq * corresponding to the target assist current Ias are calculated by the assist current command unit 42a, but only a q-axis armature current in the dq coordinate system is commanded to be energized. The d-axis armature current is set to “0”.

Subsequently, the electric motor 15 is energized so as to have the determined target assist current value to generate a predetermined assist torque (S105).
By repeatedly executing such processing, an appropriate assist current according to the battery state can be supplied to the electric motor 15.

  The assist control routine is started when the ignition switch 80 is turned on. However, when the period from the last turn-off operation of the ignition switch 80 to the current on-operation has passed a predetermined period (for example, half a year), Since the battery state may have changed significantly, the previous battery diagnosis result (deterioration degree D) described above is invalidated and the assist upper limit current value Iasmax set according to the deterioration degree D is ignored. . That is, the assist upper limit current value Iasmax is not limited. Alternatively, the assist upper limit current value Iasmax may be corrected.

According to the electric power steering apparatus 1 including the battery state diagnosis apparatus of the present embodiment described above, the following effects are obtained.
1. After the power supply to various electric control systems ES is stopped by turning off the ignition switch 80, the electric motor 15 of the electric power steering apparatus 1 is energized to diagnose the battery state. There is no adverse effect on battery diagnosis due to operation or power generation of the alternator 70, and a sufficient diagnosis time can be taken, so that a highly accurate diagnosis result can be obtained.

2. Since a predetermined current can be flowed at the time of battery diagnosis using the current sensor 53 provided in the motor drive circuit 50, there is no need to provide a special current sensor for battery diagnosis, and a cost merit is obtained.

3. Since the battery diagnosis is performed by using the electric power steering apparatus 1 with a large consumption current, the value of the drawn current from the battery 60 can be increased during the battery diagnosis, and the diagnosis accuracy of the battery state is increased.

4). At the time of battery diagnosis, since only the d-axis armature current in the dq coordinate system of the electric motor 15 is allowed to flow, and not to the q-axis armature current, no rotational torque is generated and the steering handle 11 is rotated. There is no end. Therefore, the battery state can be safely diagnosed for the driver.
For this reason, it is not necessary to have a complicated configuration such as driving a plurality of electric motors in opposite directions as in the conventional device, and the battery status can be diagnosed with a simple configuration without changing the vehicle status. It will be highly versatile.

5). When passing the d-axis armature current, an upper limit current value is set according to the motor temperature, and current is supplied within the range of the upper limit current value, thus preventing demagnetization of the permanent magnet of the rotor. can do.

6). At the time of battery diagnosis, since the energization amount to the electric motor 15 is gradually increased, a problem that the battery voltage suddenly decreases and the constantly energizing system of the vehicle goes down is prevented. Even if a rotational torque is applied to the electric motor 15, it is safe because it does not operate suddenly.

7. By intermittently energizing the electric motor 15, the power consumption of the battery 60 can be suppressed. Further, since the current value is increased in accordance with the increase in the number of energizations, a rapid energization to the electric motor 15 is avoided, and the battery voltage does not suddenly decrease. In addition, when the battery diagnosis is performed before the number of energizations reaches the predetermined number, the energization is terminated at that time, so that the power consumption of the battery 60 can be suppressed also in this respect.

8). In determining the battery deterioration, the voltage value (detection voltage V3i) in the initial state of the actual battery is compared with the voltage value (detection voltage V3x) at the time of diagnosis, and the detection voltage V3x is converted to a past measurement value. If the value is higher, the value is updated and stored as the voltage value V3i in the initial state. Therefore, there is no influence of variations in voltage characteristics due to individual differences of the battery 60, and diagnosis for the initial state is always possible. A highly accurate diagnosis result can be obtained.

9. Since the upper limit value of the assist current is determined according to the battery deterioration degree D, it is possible to prevent the amount of current supplied to the electric motor 15 from being excessively limited and to appropriately obtain the steering assist torque. On the contrary, the problem that the upper limit current value to the electric motor 15 is set too high and the power supply amount to the other electric control system ES is excessively suppressed is also prevented. As a result, it is possible to distribute the limited power of the battery 60 to each electric control system ES in a balanced manner.

10. When the elapsed time from the OFF operation of the ignition switch 80 to the next ON operation exceeds a predetermined time, the battery state diagnosis result made up to the previous time is invalidated, and the upper limit current set according to the deterioration degree D Since the value Iasmax is ignored, control using an erroneous diagnosis result can be prevented.

11. When the battery condition diagnosis start condition is being checked (before the start of energization), if it is determined that the battery 60 has deteriorated, the diagnosis is terminated at that time, so power consumption due to energization for diagnosis And further deterioration of the battery 60 can be prevented (S18 to S20).

12 If the battery voltage falls below the specified voltage while starting energization and diagnosing the battery status, the battery status is determined to be defective. The problem of further lowering is prevented (S57 to S59).

13. After starting energization of the battery 60, if it is confirmed that the battery voltage is equal to or higher than a predetermined voltage set according to the energization amount, it is determined that the battery 60 is in a good state at that time and the diagnosis is finished. Therefore, the battery 60 is not energized more than necessary, and the power consumption of the battery 60 for diagnosis can be suppressed (S62 to S64).

14 When diagnosing the battery status, check that the ignition key is removed, the door is opened and closed, and the door is locked, and the electric motor is energized in a state where it is estimated that the driver is getting off the vehicle. It is safe because it can be performed (S21 to S24). In addition, since the driver does not operate the steering handle 11, regenerative power is not generated from the electric motor 15, and the battery diagnosis is not adversely affected.

  The electric power steering apparatus 1 including the battery state diagnosis apparatus according to the present embodiment has been described above. Next, another embodiment according to the above-described diagnosis motor energization routine in step S5 will be described.

FIG. 14 shows a diagnostic motor energization routine as another embodiment, which is stored as a control program in the ROM of the electronic control unit 40 and repeatedly executed at a predetermined cycle.
First, it is determined whether or not the flag F is 1 (S501). When this routine is started, the flag F is set to 1 in the above-described step S17, so that “YES” is always determined. The flag F is set to 1 before energization of the electric motor is started, and is set to 2 during energization.

Subsequently, the process proceeds to step S502, and the energization timer is started. This energization timer measures the time from the start of energization. Then, the electric motor 15 is energized with a current value corresponding to the timer value of the energization timer (S504).
The current value corresponding to the timer value is determined based on the table of FIG. In the present embodiment, for example, the current value is gradually increased (for example, in proportion to the elapsed time) so that the d-axis armature current value Ida = 50 amperes when the energization time Ts = 5 seconds and 5 seconds have elapsed. .

  However, in step S503, it is determined whether or not the d-axis armature current upper limit value Idmax set in accordance with the motor temperature is equal to or greater than the current value Ida at the time when 5 seconds have elapsed, and it is determined that Idmax <Ida. If this is the case, the diagnostic motor energization routine is terminated.

  The amount of current flowing through the electric motor 15 is adjusted to a predetermined current by PWM control of each switching element SW11, SW12, SW21, SW22, SW31, SW32 of the motor drive circuit 50 based on a signal from the current sensor 53. Also in this case, as in the previous embodiment, only the d-axis armature current in the dq coordinate system is allowed to flow so that the electric motor 15 does not rotate.

Subsequently, the flag F is set to 2 (S505).
Next, it is determined whether or not the time measured by the energization timer exceeds the predetermined time Ts (S506), and the following processing is repeated until the predetermined time Ts is exceeded.
First, the battery detection voltage Vx is read, and it is determined whether or not the detection voltage Vx is greater than a reference voltage Vt0 set in advance according to the energization amount (S507). If Vx> Vt0, it is determined that the battery 60 is in a normal state (S508), the energization timer is cleared to zero (S509), and energization of the electric motor 15 is stopped (S510). The process proceeds to the state determination routine.
This preset reference voltage Vt0 may be considered as, for example, the voltage fluctuation characteristic L1 in FIG. That is, when the voltage characteristic of the diagnosed battery 60 is located above the normal battery voltage characteristic L1 in the graph of FIG. 10, it is determined that the battery 60 is in a normal state.

If “NO” is determined in the step S507, it is next determined whether or not the battery detection voltage Vx is lower than a predetermined voltage Vmin1 (in this embodiment, Vmin1 = 9 V) (S511). If it is determined that Vx <Vmin1, it is determined that the battery 60 is in a deteriorated state (S512), the energization timer is cleared to zero (S509), and energization to the electric motor 15 is stopped (S510). The process proceeds to the battery state determination routine of S8.
For example, in FIG. 10, the voltage variation characteristic L4 corresponds to this case.

  On the other hand, if “NO” is determined in step S511, it is further determined whether or not a battery diagnosis interruption condition is detected (S513). If a battery diagnosis interruption condition is detected, that is, When the ignition switch 80 is turned on halfway, when the key switch is inserted, when the door is opened or closed, or when the door lock is released, the energization timer is cleared to zero (S514) and to the electric motor 15 Is stopped (S515), and this control routine is terminated. That is, the diagnosis of the battery state is stopped at this time.

If the interruption condition does not occur, the routine repeatedly returns to step S501 of this routine. However, in this case, since the flag F is set to 2, the process proceeds from step S501 to step S503, and according to the timer value. The current value is increased and the above process is repeated.
When such a process is repeated and the energization timer measures the predetermined time Ts (S506: YES), the battery detection voltage Vx at that time is read and stored in a non-volatile memory provided in the electronic control unit 40 (S516). Then, the energization timer is cleared to zero (S509), the energization to the electric motor 15 is stopped (S510), and the process proceeds to the battery state determination routine of step S8.

  In this case, the battery detection voltage Vx when the predetermined time Ts has elapsed is a determination factor of the battery deterioration degree D. That is, the battery detection voltage V3x in the battery state determination routine of the previous embodiment corresponds to the battery detection voltage Vx in this embodiment. Further, the battery voltage initial value V3i may be stored and updated as the maximum value of the past battery detection voltage Vx.

  According to the diagnostic motor energization routine of another embodiment described above, since the battery state is diagnosed by one continuous energization of the electric motor 15, the chemical reaction in the battery 60 is sufficiently performed and the actual Since the battery state is diagnosed under conditions close to the usage environment, the accuracy of the diagnosis result is further improved. That is, while the vehicle is actually running, current is continuously drawn from the battery 60, but in this embodiment as well, since current is drawn over time, diagnosis under conditions close to the usage environment is possible. A highly accurate diagnosis result can be obtained.

  The electric power steering apparatus 1 including the battery deterioration apparatus according to the present embodiment has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the object of the present invention. It is.

For example, in the present embodiment, the diagnosis (energization) of the battery state is started after a predetermined time has elapsed since the ignition switch 80 was turned off. However, the diagnosis start timing is not limited to the time lapse determination by a timer, You may capture physical phenomena. For example, after detecting the turning-off operation of the ignition switch 80, it may be determined that the predetermined period has elapsed by capturing that the engine ambient temperature has decreased to a predetermined temperature.
In addition, as a condition for starting the diagnosis of the battery status, the operation of removing the ignition key, the opening / closing operation of the door, and the confirmation of the door lock state are performed. However, such a confirmation is not necessarily required, and a part of them is performed. It may be.

Further, in the present embodiment, the diagnosis of the battery state is performed using the electric power steering apparatus 1, but this is not always necessary, and a system including an electric actuator, for example, an electric control type suspension apparatus or an electric control type It is also possible to make a diagnosis using a brake device or the like.
Furthermore, the current value need not be measured using the current sensor 53 of the motor drive circuit 50. For example, the current value may be measured by providing a current sensor in the battery terminal portion 61.
Moreover, numerical values such as a voltage value, a current value, a time, and the number of energizations in the embodiment are merely examples, and can be arbitrarily set.

It is a whole lineblock diagram of an electric power steering device provided with a battery state diagnostic device concerning an embodiment of the present invention. It is a schematic circuit block diagram mainly showing a power supply system of an electric power steering device. It is a functional block diagram showing the function of a motor control part. It is a flowchart showing the whole battery state diagnostic control routine. It is a flowchart showing a diagnosis start condition check routine. It is a flowchart showing a motor energization routine for diagnosis. It is a flowchart showing a battery state determination routine. It is a timing chart showing the state after the ignition switch is turned off. It is a graph showing the change of an energization current and battery voltage. It is a graph showing the battery voltage characteristic with respect to the increase in an energization current. It is explanatory drawing showing the table for calculating an assist upper limit electric current value. It is explanatory drawing showing the table for calculating a required assist current. It is a flowchart showing an assist control routine. It is a flowchart showing the motor energization routine for diagnosis as other embodiments. It is a graph showing the change of an energization current. It is explanatory drawing showing the table for calculating d-axis armature current upper limit. It is explanatory drawing of a dq coordinate system.

Explanation of symbols

Electric power steering device ... 1, steering assist mechanism ... 10, electric motor ... 15, electronic control device ... 40, battery diagnostic unit ... 41, motor control unit ... 42, motor drive circuit ... 50, current sensor ... 53, battery ... 60 , Alternator ... 70, ignition switch ... 80, key switch ... 83, other electric control system ... ES, permanent magnet ... MG.

Claims (12)

In a battery state diagnosis device for diagnosing the state of a battery that supplies power to a plurality of electric control systems provided in a vehicle
Energization means for energizing a specific electrical control system among the plurality of electrical control systems after power supply to the electrical control systems is stopped by turning off an ignition switch;
Energization amount detection means for detecting the amount of current flowing through the specific electrical control system;
Voltage fluctuation detection means for detecting a voltage fluctuation state of the battery during the energization operation by the energization means;
Battery state diagnosis means for diagnosing the state of the battery based on the detected energization amount and the voltage fluctuation state of the battery;
With
The battery state diagnosis apparatus , wherein the energization means gradually increases an energization amount to the specific electric control system . The specific electrical control system is
An electric power steering apparatus comprising: an electric motor that applies a predetermined steering torque to a steered wheel; and a motor control unit that detects and controls the amount of power supplied to the electric motor according to an operation state of the steering handle by a current sensor. The battery state diagnosis apparatus according to claim 1, wherein: The electric motor is composed of a brushless DC motor,
The motor control means is the energization means from a d-axis serving as a magnetic flux acting axis created by a permanent magnet of the rotor of the brushless DC motor and a q-axis orthogonal to the d-axis at the time of battery condition diagnosis. 3. The battery state diagnosis apparatus according to claim 2 , wherein only the d-axis armature current in the dq coordinate system is supplied and current is supplied so as not to flow the q-axis armature current.   In a battery state diagnosis device for diagnosing the state of a battery that supplies power to a plurality of electric control systems provided in a vehicle,
  Energization means for performing predetermined energization to a specific electrical control system among the plurality of electrical control systems after power supply to the electrical control systems is stopped by turning off an ignition switch;
  Energization amount detection means for detecting the amount of current flowing through the specific electrical control system;
  Voltage fluctuation detection means for detecting a voltage fluctuation state of the battery during the energization operation by the energization means;
  Battery state diagnosis means for diagnosing the state of the battery based on the detected energization amount and the voltage fluctuation state of the battery;
  With
  The specific electrical control system is
  An electric power steering apparatus comprising: an electric motor that applies a predetermined steering torque to a steered wheel; and a motor control unit that detects and controls the amount of power supplied to the electric motor according to an operation state of the steering handle by a current sensor. Yes,
  The battery condition diagnosis apparatus, wherein the motor control means intermittently energizes the electric motor. 4. The battery state diagnosis apparatus according to claim 2 , wherein the motor control means energizes the electric motor continuously. In a battery state diagnosis device for diagnosing the state of a battery that supplies power to a plurality of electric control systems provided in a vehicle
Energization means for energizing a specific electrical control system among the plurality of electrical control systems after power supply to the electrical control systems is stopped by turning off an ignition switch;
Energization amount detection means for detecting the amount of current flowing through the specific electrical control system;
Voltage fluctuation detection means for detecting a voltage fluctuation state of the battery during the energization operation by the energization means;
Battery state diagnosis means for diagnosing the state of the battery based on the detected energization amount and the voltage fluctuation state of the battery;
And a storage means for storing battery voltage change data when the battery condition diagnosis,
The battery state diagnostic device diagnoses the state of the battery based on the stored past battery voltage fluctuation data and the battery voltage fluctuation value at the time of the current diagnosis.   In a battery state diagnosis device for diagnosing the state of a battery that supplies power to a plurality of electric control systems provided in a vehicle,
  Energization means for performing predetermined energization to a specific electrical control system among the plurality of electrical control systems after power supply to the electrical control systems is stopped by turning off an ignition switch;
  Energization amount detection means for detecting the amount of current flowing through the specific electrical control system;
  Voltage fluctuation detection means for detecting a voltage fluctuation state of the battery during the energization operation by the energization means;
  Battery state diagnosis means for diagnosing the state of the battery based on the detected energization amount and the voltage fluctuation state of the battery;
  With
  The specific electrical control system is
  An electric power steering apparatus comprising: an electric motor that applies a predetermined steering torque to a steered wheel; and a motor control unit that detects and controls the amount of power supplied to the electric motor according to an operation state of the steering handle by a current sensor. Yes,
  An apparatus for diagnosing a battery condition, comprising: an upper limit current value determining means for determining an upper limit current value for allowing energization to the electric motor of the electric power steering apparatus based on the diagnosed battery condition. If the elapsed time from the OFF operation of the ignition switch to the next on-operation exceeds a predetermined time, according to claim 6 or claim, characterized in that disabling the diagnostic results of the battery condition made up to the previous 8. The battery state diagnosis device according to 7 . Before energizing a specific electrical control system by the energization means, the pre-energization voltage detection means for detecting the battery voltage;
Only when the battery voltage before the power supply is equal to or higher than the reference voltage, according to claim 1 to claim, characterized in that a current diagnosis permission means for starting the diagnosis of the battery condition to allow the energization of said energizing means The battery state diagnosis apparatus according to any one of 8 . The battery state diagnosis unit starts diagnosis by energization of the energization unit, and stops the energization of the energization unit and terminates the diagnosis when the battery voltage falls below a predetermined voltage on the way. The battery state diagnosis apparatus according to any one of claims 1 to 9 . The battery state diagnosis unit determines that the battery is in a good state when the battery voltage is equal to or higher than a predetermined voltage set according to the energization amount after starting diagnosis by energization of the energization unit. The battery state diagnosis apparatus according to claim 1 , wherein the energization of the energization unit is stopped and the diagnosis is terminated. In a battery state diagnosis device for diagnosing the state of a battery that supplies power to a plurality of electric control systems provided in a vehicle,
Energization means for energizing a specific electrical control system among the plurality of electrical control systems after power supply to the electrical control systems is stopped by turning off an ignition switch;
Energization amount detection means for detecting the amount of current flowing through the specific electrical control system;
Voltage fluctuation detection means for detecting a voltage fluctuation state of the battery during the energization operation by the energization means;
Battery state diagnosis means for diagnosing the state of the battery based on the detected energization amount and the voltage fluctuation state of the battery;
With
The specific electrical control system is
An electric power steering apparatus comprising: an electric motor that applies a predetermined steering torque to a steered wheel; and a motor control unit that detects and controls the amount of power supplied to the electric motor according to an operation state of the steering handle by a current sensor. Yes,
The motor control means confirms that the ignition key is removed based on a detection signal from a key detection means for detecting insertion / removal of the ignition key, and energizes the electric motor of the electric power steering device. A battery condition diagnosis apparatus characterized by the above.

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