JP2017005899A - Drive control device of wheel independent drive type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive control device of a wheel independent drive type vehicle, which decreases unintentional braking on the vehicle without complicating the structure.SOLUTION: A drive control device 20 is mounted on a vehicle provided with right and left motors 6 which individually drive right and left drive wheels, and comprises an ECU 21 and inverter devices 22. Abnormality detection means 34 is provided in each drive system and detects abnormality occurring in the drive system. Abnormality-responding torque distribution change means 35 is provided for, when a control signal from the inverter device 22 to the motor 6 in the drive system on which abnormality is detected, is stopped, calculating regenerative torque generated by the motor 6 in the drive system on which abnormality is detected, on the basis of a relation between power supply voltage for motor drive and motor rotation speed, and distributing torque which is reverse to the regenerative torque and is calculated based on the absolute value of the regenerative torque, to the motors 6 in the drive system on which no abnormality is detected.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a drive control device for a wheel independent drive type vehicle, and relates to a technique for performing fail-safe in a region where a back electromotive voltage exceeds a power supply voltage.

  Vehicles equipped with motors that drive drive wheels have been put into practical use. Among the above-mentioned motors, some of the small and high-power motors have high rotation and the peak of the back electromotive voltage exceeds the power supply voltage. In such a situation, field weakening control is generally performed in which torque control is performed while suppressing a counter electromotive voltage by flowing a d-axis current in vector control.

  However, when control cannot be performed due to an abnormality in the inverter, motor, sensors, etc., and energization of the motor is stopped, the peak of the back electromotive voltage exceeds the power supply voltage, and power is generated from the motor to the battery via the inverter. At the same time as the current flows, regenerative torque is generated. As a result, an unintended brake is applied to the vehicle.

Japanese Patent Laid-Open No. 11-46406 JP-A-11-262101

In the prior art, the situation is not exactly the same, but when an abnormality or the like occurs, a technique for opening a motor output line with a relay or the like (Patent Document 1), or a technique for providing a mechanism such as a clutch in an in-wheel motor (Patent Document) 2) has been proposed.
However, if a relay or the like is attached to the motor output line, the wiring resistance increases, the circuit becomes complicated, and the cost increases. If a mechanism such as a clutch is provided in the in-wheel motor, the structure of the motor becomes complicated, resulting in an increase in motor size and cost.

  An object of the present invention is to provide a drive control device for a wheel-independent drive vehicle that can reduce unintentional braking on the vehicle without complicating the structure.

The wheel independent drive type vehicle drive control device 20 of the present invention is mounted on a vehicle including left and right motors 6 and 6 for individually driving left and right drive wheels 2 and 2, respectively.
An ECU 21 that generates and outputs a command torque in response to an operation of the operation units 16 and 17;
An inverter device having a power circuit unit 28 including an inverter 31 for converting DC power to AC power, and a motor control unit 29 for controlling torque of the motor 6 via the power circuit unit 28 in accordance with the command torque given from the ECU 21. 22,
In the drive control device 20 of the wheel independent drive type vehicle provided with
An abnormality detection means 34 provided for each drive system K including each motor 6 and the inverter device 22 connected to each motor 6, and detecting an abnormality occurring in the drive system K;
When the control signal from the inverter device 22 to the motor 6 in the drive system K in which the abnormality is detected by the abnormality detection means 34 is stopped, based on a predetermined relationship between the motor driving power supply voltage and the motor rotation speed, The regenerative torque generated by the motor 6 in the drive system K in which the abnormality is detected is calculated, and the torque obtained in the opposite direction to the regenerative torque and based on the absolute value of the regenerative torque is calculated in the drive system K in which no abnormality is detected. An abnormality corresponding torque distribution changing means 35 for distributing to the motor 6;
Is provided.
The defined relationship is determined by the results of tests, simulations, and the like.

According to this configuration, when the vehicle is driven, the abnormality detection means 34 detects each abnormality that has occurred in the drive system K including each motor 6 and the inverter device 22 connected to each motor 6. As the abnormality detected by the abnormality detection means 34, (1) a detection system abnormality, (2) a power supply system abnormality, and (3) a wiring system abnormality are conceivable. (1) The detection system abnormality includes, for example, an abnormality in the current sensor 38 that detects the current flowing through the motor 6, a detection circuit, and the like, disconnection or short-circuit of those electric wires. (2) The abnormality in the power supply system includes, for example, an abnormality in the motor control unit 29 or the power circuit unit 28. (3) As an abnormality of the wiring system, there is a disconnection or a short circuit of the motor wire.
For example, when a current corresponding to a command torque supplied from the ECU 21 is not detected for a certain drive system K, the abnormality detection means 34 detects that a detection system or power supply system abnormality has occurred in the drive system K.

  When the control signal from the inverter device 22 to the motor 6 in the drive system K in which the abnormality is detected is stopped, the abnormality corresponding torque distribution changing unit 35 detects the abnormality based on the determined relationship between the power supply voltage and the motor rotation speed. The regenerative torque generated by the motor 6 in the detected drive system K is calculated. Further, the abnormality-corresponding torque distribution changing unit 35 distributes the torque obtained based on the absolute value of the regenerative torque in the reverse direction to the calculated regenerative torque to the motor 6 in the drive system K in which no abnormality is detected (normal).

  Thus, when the control signal to the motor 6 in a certain drive system K is stopped, even if the peak of the back electromotive voltage exceeds the power supply voltage and the regenerative torque is generated, the regenerative torque is in the opposite direction. Thus, since the torque obtained based on the absolute value of the regenerative torque is distributed to the motor 6 in the normal drive system K, it is possible to reduce the unintended braking on the vehicle. In this case, it is possible to reduce the occurrence of unintended braking without complicating the structure as compared with the conventional technique in which a relay or a mechanism is provided.

  The abnormality-corresponding torque distribution changing means 35 calculates the total driving calculated so that the total driving torque calculated based on the command torque, which is the sum of the torques applied to all the motors 6, does not change before and after the abnormality is detected. A drive torque obtained by adding a torque opposite to the regenerative torque generated by the motor 6 in the drive system K in which the abnormality is detected may be distributed to the motor 6 in the drive system K in which no abnormality is detected. In this case, since the change of the total driving torque can be suppressed before and after the abnormality detection by the abnormality detection means 34, the vehicle driver can continue the driving operation of the vehicle without a sense of incongruity.

  The abnormality-corresponding torque distribution changing means 35 applies the calculated regenerative torque to the motor 6 in the drive system K in which no abnormality is detected so that the left-right torque distribution ratio in the vehicle does not change before and after the abnormality detection. The torque obtained in the reverse direction and based on the absolute value of the regenerative torque may be distributed. In this case, since it is possible to suppress the change in the torque distribution ratio in the left-right direction of the vehicle before and after the abnormality detection, it is possible to continue the driving operation without any trouble even if the vehicle goes straight or turns.

  The motor 6 includes an in-wheel motor drive device including the motor 6, a wheel bearing 4 that supports the drive wheel 2, and a speed reducer 7 that decelerates and transmits the rotation of the motor 6 to the wheel bearing 4. It is good also as what comprises IWM.

  A drive control device for a wheel independent drive vehicle according to the present invention is mounted on a vehicle including left and right motors that individually drive left and right drive wheels, and generates and outputs a command torque in accordance with an operation of an operation unit; A power circuit unit including an inverter for converting DC power into AC power, and an inverter device having a motor control unit for torque controlling the motor via the power circuit unit according to the command torque provided from the ECU. In a drive control device for a wheel independent drive type vehicle, an abnormality detection means provided for each drive system including each of the motors and an inverter device connected to each of the motors, and detecting an abnormality occurring in the drive system, and the abnormality When the control signal from the inverter device to the motor in the drive system in which the abnormality is detected by the detecting means is stopped Based on a predetermined relationship between the power supply voltage for driving the motor and the motor rotation speed, a regenerative torque generated by the motor in the drive system in which the abnormality is detected is calculated, and the regenerative torque is in a direction opposite to the regenerative torque. There is provided an abnormality corresponding torque distribution changing means for distributing the torque obtained based on the absolute value to the motor in the drive system in which no abnormality is detected. For this reason, it is possible to reduce unintended braking on the vehicle without complicating the structure.

It is a block diagram of the conceptual composition which shows the electric vehicle carrying the drive control device concerning the embodiment of this invention with a top view. It is sectional drawing of the in-wheel motor drive device in the same electric vehicle. It is a block diagram of a control system of the drive control device. It is circuit diagrams, such as an inverter of the drive control apparatus. It is a figure which shows the relationship between a motor rotation speed and output torque. It is a figure which shows the relationship between the peak value of a back electromotive force, and a motor rotation speed. It is a figure which shows the example of a torque distribution when abnormality generate | occur | produces in a left rear wheel. It is a figure which shows the example which distributes torque so that total drive torque may not change before and after abnormality detection. It is a figure which shows the example which distributes torque so that the torque distribution ratio of the left-right direction of a vehicle may not change before and after abnormality detection. It is a figure which shows the other example which distributes torque so that the torque distribution ratio of the left-right direction of a vehicle may not change before and after abnormality detection.

An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram of a conceptual configuration showing a plan view of an electric vehicle that is a vehicle equipped with a drive control device according to this embodiment. This electric vehicle is a four-wheeled vehicle in which the wheels 2 that are the left and right rear wheels of the vehicle body 1 are drive wheels and the wheels 3 that are the left and right front wheels are driven wheels. The front wheel 3 is a steering wheel. The wheels 3 and 3 which are the steering wheels as the left and right front wheels can be steered via a steering mechanism (not shown) and are steered by a steering means 15 such as a steering wheel. The left and right wheels 2 and 2 serving as driving wheels are driven by independent traveling motors 6. Each motor 6 constitutes an in-wheel motor drive device IWM described later. Each wheel 2 and 3 is provided with a brake (not shown).

  FIG. 2 is a cross-sectional view of the in-wheel motor drive device IWM in this electric vehicle. Each in-wheel motor drive unit IWM has a motor 6, a speed reducer 7, and a wheel bearing 4, and a part or all of these are arranged in the wheel. The rotation of the motor 6 is transmitted to the drive wheel 2 via the speed reducer 7 and the wheel bearing 4. A brake rotor 5 constituting the brake is fixed to a flange portion of the hub wheel 4 a of the wheel bearing 4, and the brake rotor 5 rotates integrally with the drive wheel 2. The motor 6 is, for example, an embedded magnet type synchronous motor in which a permanent magnet is built in the core portion of the rotor 6a. This motor 6 is a motor in which a radial gap is provided between a stator 6 b fixed to the housing 8 and a rotor 6 a attached to the rotation output shaft 9.

The control system will be described.
As shown in FIG. 1, a drive control device 20 including an ECU 21 and a plurality (two in this example) of inverter devices 22 is mounted on the vehicle body 1. The ECU 21 is a higher-level control unit that performs overall control of the entire vehicle and gives commands to the inverter devices 22. Each inverter device 22 controls each traveling motor 6 according to a command from the ECU 21. The ECU 21 includes a computer, a program executed by the computer, various electronic circuits, and the like.

  The ECU 21 includes a command torque calculation unit 47 and torque distribution means 48. The command torque calculation unit 47 mainly sends the travel motors 6 and 6 for the left and right wheels 2 and 2 based on the accelerator opening signal output from the accelerator operation unit 16 and the deceleration command output from the brake operation unit 17. The acceleration / deceleration command to be applied is generated as a command torque. The torque distribution unit 48 considers the acceleration / deceleration command calculated by the command torque calculation unit 47 in consideration of a turning command output from a steering angle sensor (not shown) that detects the steering angle of the steering unit 15. Are output to each inverter device 22 so as to be distributed to the traveling motors 6 and 6.

  Further, the command torque calculation unit 47 generates a braking torque command value for causing the motor 6 to function as a regenerative brake and a braking torque command value for a brake (not shown) when a deceleration command output from the brake operation unit 17 is received. Has the function of distributing. The braking torque command value that functions as a regenerative brake is reflected in the command torque of the acceleration / deceleration command given to the motors 6 and 6 for traveling. The accelerator operation unit 16 and the brake operation unit 17 include an accelerator pedal and a brake pedal, respectively, and an accelerator sensor 16a and a brake sensor 17a that detect an operation amount of each pedal, respectively. The battery 19 is mounted on the vehicle body 1 and is used as a drive for the motor 6 and as a power source for the electrical system of the entire vehicle.

  FIG. 3 is a block diagram of a control system of the drive control device 20. Hereinafter, description will be made with reference to FIG. 1 as appropriate. The inverter device 22 includes a power circuit unit 28 provided for each motor 6 and a motor control unit 29 that controls the power circuit unit 28. The motor control unit 29 has a function of outputting information (eg, motor rotation speed, control torque, abnormality information, etc.) such as detection values and control values related to the in-wheel motor drive device IWM of the motor control unit 29 to the ECU 21. Have

Here, FIG. 5 is a diagram showing the relationship between the motor speed and the output torque. The maximum motor torque T _MA decreases as the motor speed increases. Therefore, in order to obtain the maximum torque T _MA when the accelerator operating unit 16 (FIG. 1) is fully depressed, as shown in FIG. 3, the command torque calculating unit 47 is provided with an accelerator output from the accelerator sensor 16a. It is necessary to calculate the command torque from the opening degree signal and the motor rotation speed given to the ECU 21.

  The power circuit unit 28 includes an inverter 31 and a PWM driver 32 that drives the inverter 31. The inverter 31 converts the DC power of the battery 19 (FIG. 1) into three-phase AC power used for driving the motor 6. As shown in FIG. 4, the inverter 31 includes a plurality of semiconductor switching elements 18, and the PWM driver 32 (FIG. 3) drives the inverter 31 based on an on / off command. The semiconductor switching element 18 includes, for example, an insulated gate bipolar transistor (IGBT).

  As shown in FIG. 3, the motor control unit 29 includes a motor drive control unit 30 as a basic control unit. The motor drive control unit 30 converts it into a current command and performs pulse width modulation in accordance with an acceleration / deceleration command based on a command torque given from the ECU 21, and gives an on / off command to the PWM driver 32. The motor drive control unit 30 obtains a motor current flowing from the inverter 31 to the motor 6 from the current sensor 38, and performs current feedback control (control by a control signal). Further, the motor drive control unit 30 obtains the rotation angle of the rotor 6a (FIG. 2) of the motor 6 from the rotation angle detection means 36, and performs vector control (control by a control signal). For example, a resolver or the like is applied as the rotation angle detection unit 36.

  In this embodiment, the drive control device 20 having the above-described configuration is provided with an abnormality detection means 34 and an abnormality handling torque distribution changing means 35.

  The abnormality detection means 34 detects an abnormality that has occurred in the drive system K. The abnormality detection means 34 is provided for each drive system K including each motor 6 and the inverter device 22 connected to each motor 6. In this example, the drive system K is connected to the motor control unit 29 of the inverter device 22 (the motor 6 for the left wheel 2 and the inverter device 22 are one drive system K) corresponding to the motor 6 for driving the left wheel 2. An abnormality detection means 34 is provided for detecting an abnormality that has occurred. In addition, the motor system 29 of the inverter device 22 (the motor 6 for the right wheel 2 and the inverter device 22 are one drive system K) corresponding to the motor 6 for driving the right wheel 2 is generated in the drive system K. An abnormality detection means 34 for detecting an abnormality is provided.

As the abnormality detected by the abnormality detection means 34, (1) a detection system abnormality, (2) a power supply system abnormality, and (3) a wiring system abnormality are conceivable.
(1) The detection system abnormality includes, for example, a current sensor 38 that detects a current flowing through the motor 6, an abnormality in its detection circuit (not shown), and disconnection or short-circuit of those wires. Other examples of abnormality in the detection system include abnormality in the rotation angle detection means 36, abnormality in its detection circuit (not shown), disconnection or short circuit of those wires.
(2) Examples of the abnormality in the power supply system include an abnormality in the motor drive control unit 30, an abnormality in the PWM driver 32, and an abnormality in the semiconductor switching element 18.
(3) As an abnormality of the wiring system, there is a disconnection or a short circuit of the motor wire.

For example, the abnormality detection unit 34 determines that an abnormality of the detection system or the power supply system has occurred in the drive system K when a current corresponding to the command torque supplied from the ECU 21 is not detected from the current sensor 38 for a certain drive system K. To detect. Further, the abnormality detection means 34, for example, for a certain drive system K, the motor angular acceleration detected and calculated by the rotation angle detection means 36 deviates by more than a threshold from the motor angular acceleration corresponding to the command torque given from the ECU 21. When the drive system K detects that an abnormality of the detection system or the power supply system has occurred.
The current corresponding to the command torque, the motor angular acceleration corresponding to the command torque, and the threshold are determined, for example, by results of tests and simulations. same as below.

  For example, when the current detected from the current sensor 38 deviates from the current corresponding to the command torque given from the ECU 21 by a threshold value or more for a certain drive system K, the abnormality detection unit 34 supplies power to the drive system K. Detects that a supply system abnormality or wiring system abnormality has occurred.

  The abnormality corresponding torque distribution changing means 35 is provided in the torque distribution means 48 in the ECU 21. The abnormality-corresponding torque distribution changing unit 35 includes a determination unit 35a, a regenerative torque calculating unit 35b, and a torque distribution changing unit 35c. The determination unit 35a determines whether or not the control signal from the inverter device 22 to the motor 6 in the drive system K in which the abnormality is detected by the abnormality detection unit 34 is stopped. Specifically, when a certain abnormality detecting means 34 detects an abnormality, the motor control unit 29 gives abnormality information to the ECU 21 together with the control torque and the motor rotational speed of the motor 6 in the drive system K where the abnormality is detected. .

  When the determination unit 35a determines that the control signal from the inverter device 22 of the drive system K to the motor 6 is stopped from the given abnormality information, the regenerative torque calculation unit 35b is configured to supply the motor drive power supply voltage and the motor rotation. Based on the determined relationship with the number, the regenerative torque generated by the motor 6 in the drive system K where the abnormality is detected is calculated. The torque distribution changing unit 35c applies torque calculated in the reverse direction to the calculated regenerative torque and based on the absolute value of the regenerative torque to the motor 6 in the drive system K (normal drive system K) in which no abnormality is detected. Distribute.

  As shown in FIG. 2, since the motor 6 is an embedded magnet type synchronous motor in which a permanent magnet is built in the core portion of the rotor 6a, even if the control signal to the motor 6 is stopped, When the motor 6a is rotating freely, a voltage is generated in the winding of the motor 6. This voltage becomes a counter electromotive voltage to the inverter device side. FIG. 6 is a diagram showing the relationship between the peak value of the back electromotive force and the motor rotation speed. As the motor speed increases, the peak value of the back electromotive voltage increases.

  As shown in FIGS. 3 and 6, when the peak value of the back electromotive voltage is equal to or lower than the power supply voltage (the voltage of the battery 19 (FIG. 1)), the generated current does not flow from the motor 6 to the battery 19 (FIG. 1). Torque is not generated. That is, when the peak value of the back electromotive voltage is equal to or lower than the predetermined motor rotation speed Na, which is equal to or lower than the power supply voltage, no regenerative torque is generated, which is not a practical problem. The determined motor rotation speed Na is determined by the results of tests and simulations.

  When the peak value of the back electromotive voltage exceeds the power supply voltage (the voltage of the battery 19 (FIG. 1)), the generated current flows from the motor 6 to the battery 19 (FIG. 1) via the inverter 31. At the same time, regenerative torque is generated, and as a result, unintended braking is applied to the vehicle. Therefore, the torque distribution changing unit 35c applies torque that is opposite to the calculated regenerative torque and has the same absolute value as the regenerative torque to the motor 6 in the drive system K (normal drive system K) in which no abnormality is detected. Distribute.

  Hereinafter, with reference to FIGS. 7 to 10, an example of torque distribution when the left and right rear wheels 2 and 2 and the left and right front wheels 3 and 3 of the vehicle body 1 are driven wheels driven by independent motors 6 will be described. Hereinafter, description will be made with reference to FIG. 3 as appropriate. In this case, although not shown, the inverter device 22 (FIG. 3) is provided for each motor 6.

  FIG. 7A shows when the drive systems of the left and right front and rear wheels 3 and 2 are normal. At this time, torques of A, B, C, and D Newton meters (N · m) are generated in the left front wheel 3, the left rear wheel 2, the right front wheel 3, and the right rear wheel 2, respectively. In the figure, the direction of the arrow indicates the direction of torque, and the length of the arrow indicates the magnitude of torque. same as below. As shown in FIG. 7B, when an abnormality occurs in the drive system of the left rear wheel 2, if a regenerative torque B ′ (N · m) is generated in the left rear wheel 2, an abnormality occurs. The corresponding torque distribution changing means 35 (FIG. 3) distributes the torque (−B ′ (N · m)) opposite to the regenerative torque to the remaining three wheels.

  For example, when the regenerative torque generated in the left rear wheel 2 is B ′ (N · m) = − (e + f + g) and the regenerative torque calculating unit 35b (FIG. 3) calculates, the torque distribution changing unit 35c (FIG. 3) Torque of e (N · m) is distributed to the front wheel 3, f (N · m) is distributed to the right front wheel 3, and g (N · m) is distributed to the right rear wheel 2. Then, A + e = A ′ (N · m) is generated in the left front wheel 3, C + f = C ′ (N · m) is generated in the right front wheel 3, and D + g = D ′ (N · m) is generated in the right rear wheel 2. .

  FIG. 8A shows when the drive systems of the left and right front and rear wheels 3 and 2 are normal. At this time, torques of A, B, C, and D Newton meters (N · m) are generated in the left front wheel 3, the left rear wheel 2, the right front wheel 3, and the right rear wheel 2, respectively. As shown in FIG. 8B, when an abnormality occurs in the drive system of the left rear wheel 2, the torque distribution changing unit 35c (FIG. 3) has a total drive torque (Total TRQ) calculated based on the command torque. In order not to change before and after the abnormality detection, a drive torque obtained by adding a torque opposite to the regenerative torque generated for the motor 6 in the drive system in which the abnormality is detected to the calculated total drive torque is obtained as a normal drive system. It may be distributed to the motor 6 in FIG.

In this case, the total drive torque Total TRQ is expressed as follows.
Total TRQ = A + B + C + D (Normal)
= A + (h + i + j) + C + D
= A + (h + i + j) + C + D + B ′ + (e + f + g) (when abnormal)
= (A + e + h) + (C + f + i) + (D + g + j) + B ′
= A '+ B' + C '+ D'
The following relationship is established between B and A ′ to D ′.
B = h + i + j, B ′ = − (e + f + g)
A ′ = A + e + h, C ′ = C + f + i, D ′ = D + g + j

  That is, when the regenerative torque generated in the left rear wheel 2 is B ′ (N · m) = − (e + f + g) and the regenerative torque calculator 35b (FIG. 3) calculates when the drive system of the left rear wheel 2 is abnormal, torque distribution The changing unit 35c (FIG. 3) includes e + h (N · m) for the left front wheel 3, f + i (N · m) for the right front wheel 3, and the right rear wheel so that the total drive torque Total TRQ does not change before and after the abnormality detection. The torque of g + j (N · m) is distributed to 2.

  FIG. 9A shows a state in which the drive system of the left and right front and rear wheels 3 and 2 is normal. At this time, torques A, B, C, and D (N · m) are generated in the left front wheel 3, the left rear wheel 2, the right front wheel 3, and the right rear wheel 2, respectively. As shown in FIG. 9B, when an abnormality occurs in the drive system of the left rear wheel 2, the torque distribution changing unit 35c (FIG. 3) changes the torque distribution ratio in the left-right direction of the vehicle before and after detecting the abnormality. Torque may be distributed to the motor 6 in the drive system in which no abnormality is detected. In this example, the torque is distributed to the motor 6 of the normal drive system so that the torque distribution ratio in the left-right direction does not change before and after the abnormality detection without changing the total drive torque before and after the abnormality detection.

If the torque of the left front wheel 3, left rear wheel 2, right front wheel 3, and right rear wheel 2 at the time of abnormality is A ′, B ′, C ′, D ′ (N · m), respectively, the torque distribution ratio in the left-right direction is Since it is the same at normal time and abnormal time, the following equation holds. (A + B): (C + D) = (A ′ + B ′): (C ′ + D ′)
Then, the torque distribution changing unit 35c (FIG. 3) generates a torque of A + B + (− B ′) = A ′ (N · m) on the left front wheel 3.

As shown in FIG. 10, the torque distribution changing unit 35c (FIG. 3) detects the abnormality so that the total torque is changed before and after the abnormality detection so that the left and right torque distribution ratio does not change before and after the abnormality detection. Torque may be distributed to the motor 6 in the drive system that is not.
When the torque A ′ = A + B + (− B ′) of the left front wheel 3 exceeds the maximum outputable torque at the time of abnormality as shown in FIG. 9B, the torque of the right wheels 3 and 2 is lowered. There is no choice but to balance the torque in the left / right direction. Specifically, as shown in FIG. 10B, the torque distribution changing unit 35 c (FIG. 3) has C ′ (where C> C ′) (N · m) and right rear wheel 2 on the right front wheel 3. The torque D ′ (where D> D ′) (N · m) is distributed.

The effect will be described.
According to the drive control apparatus 20 described above, the abnormality detection unit 34 detects an abnormality occurring in the drive system when the vehicle is driven. If the determination unit 35a determines that the control signal to the motor 6 of a certain drive system has stopped from the given abnormality information or the like, the regenerative torque calculation unit 35b regenerates the motor 6 in the drive system in which the abnormality is detected. Calculate the torque. Further, the torque distribution changing unit 35c distributes the torque obtained in the reverse direction to the regenerative torque calculated by the regenerative torque calculating unit 35b and based on the calculated absolute value of the regenerative torque to the motor 6 in the normal drive system.

  As described above, when the control signal to the motor 6 in a certain drive system is stopped, even if the peak of the back electromotive voltage exceeds the power supply voltage and the regenerative torque is generated, the regenerative torque is in the opposite direction to the regenerative torque. Since the torque obtained based on the absolute value of the motor is distributed to the motor 6 in the normal drive system, it is possible to reduce the unintended braking on the vehicle. In this case, it is possible to reduce the occurrence of unintended braking without complicating the structure as compared with the conventional technique in which a relay or a mechanism is provided.

  The drive torque obtained by adding the reverse torque to the regenerative torque generated for the motor 6 in the drive system in which the abnormality is detected to the calculated total drive torque so that the total drive torque does not change before and after the abnormality is detected. When distributing to the motors 6 of the various drive systems, the change in the total drive torque can be suppressed before and after the abnormality detection. For this reason, the driver of the vehicle can continue the driving operation of the vehicle without a sense of incongruity.

  When torque is distributed to the motor 6 of the normal drive system so that the left-right torque distribution ratio in the vehicle does not change before and after the abnormality detection, the left-right torque distribution ratio of the vehicle changes before and after the abnormality detection. Therefore, it is possible to continue the driving operation without trouble even if the vehicle goes straight or turns.

Another embodiment will be described.
As the vehicle, a two-wheel independent drive vehicle that independently drives the left and right front wheels may be applied. Further, as the vehicle, a four-wheel independent drive vehicle that drives the left and right front wheels independently and drives the left and right rear wheels independently may be applied.
The in-wheel motor drive unit IWM is a so-called direct motor type in which a cycloid reduction gear, a planetary reduction gear, a parallel two-axis reduction gear, and other reduction gears can be applied. Also good.

  As mentioned above, although the form for implementing this invention based on embodiment was demonstrated, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

2 ... wheel (drive wheel)
DESCRIPTION OF SYMBOLS 4 ... Wheel bearing 6 ... Motor 7 ... Reducer 16 ... Accelerator operation part 17 ... Brake operation part 20 ... Drive control apparatus 21 ... ECU
DESCRIPTION OF SYMBOLS 22 ... Inverter apparatus 28 ... Power circuit part 29 ... Motor control part 31 ... Inverter 34 ... Abnormality detection means 35 ... Abnormal response torque distribution change means IWM ... In-wheel motor drive device K ... Drive system

Claims (4)

Installed in vehicles with left and right motors that drive the left and right drive wheels individually,
An ECU that generates and outputs a command torque according to an operation of the operation unit;
A power circuit unit including an inverter that converts DC power into AC power, and an inverter device having a motor control unit that torque-controls the motor via the power circuit unit according to the command torque given from the ECU;
In the drive control device of the wheel independent drive type vehicle provided with
An abnormality detection means that is provided for each drive system including each motor and an inverter device connected to each motor, and detects an abnormality that has occurred in the drive system;
When the control signal from the inverter device to the motor in the drive system in which an abnormality is detected by the abnormality detection means is stopped, the abnormality is determined based on a predetermined relationship between the power supply voltage for driving the motor and the motor speed. Abnormality in which the regenerative torque generated by the motor in the detected drive system is calculated, and the torque obtained in the opposite direction to the regenerative torque and based on the absolute value of the regenerative torque is distributed to the motor in the drive system in which no abnormality is detected Corresponding torque distribution changing means,
A drive control device for a wheel independent drive type vehicle characterized by comprising:   2. The drive control device for a wheel independent drive vehicle according to claim 1, wherein the abnormality-corresponding torque distribution changing unit is configured to calculate a total drive torque that is a sum of torques applied to all the motors calculated based on the command torque. In order not to change before and after the abnormality is detected, a drive torque in which no abnormality is detected is obtained by adding the calculated total drive torque to the torque in the direction opposite to the regenerative torque generated by the motor in the drive system in which the abnormality is detected. A drive control device for a wheel independent drive type vehicle that distributes to motors in a system.   The drive control device for a wheel independent drive vehicle according to claim 1 or 2, wherein the abnormality-corresponding torque distribution changing means is configured so that the torque distribution ratio in the left-right direction in the vehicle does not change before and after the abnormality detection. A drive control device for a wheel-independent drive type vehicle that distributes torque obtained in a direction opposite to the calculated regenerative torque and based on an absolute value of the regenerative torque to a motor in a drive system in which no abnormality is detected.   4. The drive control device for a wheel independent drive type vehicle according to claim 1, wherein the motor includes the motor, a wheel bearing that supports the drive wheel, and rotation of the motor. 5. A drive control device for a wheel independent drive type vehicle that constitutes an in-wheel motor drive device including a reduction gear that decelerates and transmits the reduced gear to the wheel bearing.

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