JP7665966B2 - Vehicle drive control device - Google Patents

Description

The present invention relates to a drive control device that controls the driving state of a vehicle.

Conventionally, there is a drive control device that, when an abnormality other than motor stop is detected in the motor of one of the left or right wheels of a vehicle, controls the motor of the other wheel so that it approaches the same operating state as the operating state of the motor in which the abnormality was detected (see Patent Document 1).

Patent No. 5784930

However, in the drive control device described in Patent Document 1, if a normal motor is controlled to approach the same operating state as the operating state of the motor in which an abnormality has been detected, there is a risk that the control will not be appropriate for the abnormality. For example, if the torque of one motor suddenly decreases due to an abnormality, and the other motor is controlled to approach the same operating state, the vehicle may suddenly decelerate. On the other hand, if the torque of one motor suddenly decreases due to an abnormality, the torque difference between the left and right motors may become large, and the vehicle's behavior may become unstable if the torque of the other motor is not limited.

The present invention has been made to solve the above problems, and its main objective is to provide a vehicle drive control device that can prevent the vehicle's behavior from becoming unstable and prevent a sudden decrease in motor torque when an abnormality is detected.

The first means for solving the above problem is
A drive control device applied to a vehicle (10) including a first motor (21) that drives a first wheel (11) and a second motor (22) that drives a second wheel (12) independently of the first wheel,
A sensor (21a, 84) for detecting information related to the drive control device;
a torque setting unit (32, 132) that sets an upper limit value of torque that can be generated by the first motor and the second motor based on the information detected by the sensor;
An abnormality detection unit (52, 62) that detects an abnormality in the drive control device;
an information output unit (51, 61) configured to output, when the abnormality is detected by the abnormality detection unit, setting information for setting upper limits of the torque of the first motor and the second motor to a common predetermined value as the information to the torque setting unit;
a drive control unit (33) that controls the torques generated by the first motor and the second motor so that they are equal to or less than the upper limit value set by the torque setting unit;
Equipped with.

According to the above configuration, the drive control device is applied to a vehicle having a first motor that drives a first wheel and a second motor that drives a second wheel. The sensor detects information related to the drive control device. The torque setting unit sets an upper limit value of the torque that can be generated by the first motor and the second motor based on the information detected by the sensor. Therefore, when the information related to the drive control device detected by the sensor is information that requires setting an upper limit value of the torque that can be generated by the motor, the upper limit value of the torque is set based on that information.

Here, the abnormality detection unit detects an abnormality in the drive control device. Then, when an abnormality is detected by the abnormality detection unit, the information output unit outputs setting information for setting the upper limit value of the torque of the first motor and the second motor to a common predetermined value to the torque setting unit as the information. As a result, the torque setting unit sets the upper limit value of the torque of the first motor and the second motor to a common predetermined value based on the setting information. Then, the drive control unit controls the torque generated by the first motor and the second motor to be equal to or less than the upper limit value set by the torque setting unit. Therefore, the torque difference between the left and right motors can be reduced, and the behavior of the vehicle can be suppressed from becoming unstable. Furthermore, instead of reducing the torque generated by the first motor and the second motor, the upper limit value of the torque of the first motor and the second motor is set. Therefore, it is possible to suppress a sudden decrease in the torque of the motor, and it is possible to suppress a sudden deceleration of the vehicle. Moreover, by utilizing the upper limit torque setting unit that is generally provided in the drive control device, the torque of the motor can be limited when an abnormality is detected, and it is possible to suppress an increase in the number of additional configurations.

The drive control device generally includes a sensor that detects temperature information. In more detail, the drive control device generally includes a temperature sensor that detects the temperature of the motor, and a torque setting unit that sets the upper limit of the torque that the motor can generate based on the motor temperature.

In this regard, in the second means, the sensor detects temperature information as the information. In the third means, the temperature information is the temperature of at least one of the first motor and the second motor. Therefore, by utilizing a motor temperature sensor that is generally provided in a drive control device and a torque setting unit that sets an upper limit of the torque based on the motor temperature, the torque of the motor can be limited when an abnormality is detected.

A drive control device equipped with an AC motor generally includes a temperature sensor that detects the temperature of the power conversion unit, and a torque setting unit that sets the upper limit of the torque that the motor can generate based on the temperature of the power conversion unit.

In this regard, in the fourth means, the first motor and the second motor are AC motors, and include a first power conversion unit (INV25) that converts supplied DC power into AC power and supplies it to the first motor, and a second power conversion unit (INV26) that converts supplied DC power into AC power and supplies it to the second motor, and the sensor (21a) detects the temperature of at least one of the first power conversion unit and the second power conversion unit as the temperature information. Therefore, the torque of the motor can be limited when an abnormality is detected by utilizing a temperature sensor of the power conversion unit that is generally provided in a drive control device equipped with an AC motor, and a torque setting unit that sets an upper limit value of the torque based on the temperature of the power conversion unit.

The drive control device generally includes a temperature sensor that detects the temperature of the cooling water, and a torque setting unit that sets the upper limit of the torque that the motor can generate based on the temperature of the cooling water.

In this regard, in the fifth means, the sensor detects the temperature of the cooling water as the temperature information. Therefore, by utilizing a cooling water temperature sensor that is generally provided in a drive control device and a torque setting unit that sets an upper limit of the torque based on the cooling water temperature, the torque of the motor can be limited when an abnormality is detected.

When a high voltage is applied between the coils of a motor, the lower the air pressure, the more likely partial discharges are to occur. For this reason, the drive control device may be equipped with an air pressure sensor that detects air pressure, and may slow down the voltage rise caused by the power conversion unit the lower the detected air pressure. In this case, the slower the voltage rise is, the greater the temperature rise in the power conversion unit will be, so the drive control device may be equipped with a torque setting unit that sets the motor torque upper limit to be limited the lower the air pressure.

In this regard, in the sixth aspect, the first motor and the second motor are AC motors, and include a first power conversion unit that converts supplied DC power into AC power and supplies it to the first motor, and a second power conversion unit that converts supplied DC power into AC power and supplies it to the second motor, and the sensor detects air pressure as the information. Therefore, when the drive control device includes an air pressure sensor and a torque setting unit that sets the upper limit of the torque based on the air pressure, the torque of the motor can be limited by using them when an abnormality is detected.

The extent to which the upper limit of the motor torque should be restricted changes depending on the vehicle speed when an abnormality is detected.

In this regard, in the seventh means, the sensor (84) detects the vehicle speed as the information. Therefore, the upper limit of the torque of the first motor and the second motor can be set based on the vehicle speed when the abnormality is detected.

If no information is input from the sensor that detects information about the drive control device, there is a risk that the motor cannot be driven properly. For this reason, the drive control device generally includes a torque setting unit that sets an upper limit value for the torque that the first motor and the second motor can generate when no information is input from the sensor.

In this regard, in the eighth means, the torque setting unit sets an upper limit value of the torque that can be generated by the first motor and the second motor when the information is not input from the sensor, and the information output unit disconnects the sensor from the torque setting unit when the abnormality is detected by the abnormality detection unit. Therefore, when an abnormality is detected, it is possible to intentionally realize a state in which no information is input from the sensor to the torque setting unit. Therefore, the torque of the motor can be limited when an abnormality is detected by utilizing a torque setting unit that is generally provided in a drive control device and that sets an upper limit value of the torque of the motor when no information is input from the sensor.

The ninth means includes a current sensor (21b) that detects the current flowing through the first motor, and the abnormality detection unit predefines a predetermined range within which the relationship between a command value for the torque generated by the second motor and the current flowing through the first motor is normal, and detects the abnormality in the drive control device when the relationship between the command value and the current detected by the current sensor falls outside the predetermined range.

According to the above configuration, the current sensor detects the current flowing through the first motor. The torque generated by the first motor changes depending on the current flowing through the first motor, and if the torque difference between the first motor and the second motor becomes large, the behavior of the vehicle may become unstable. For this reason, an appropriate range of the current flowing through the first motor for the command value of the torque generated by the second motor is determined in advance.

The abnormality detection unit predefines a predetermined range within which the relationship between the command value for the torque generated by the second motor and the current flowing through the first motor is normal. The abnormality detection unit then detects an abnormality in the drive control device when the relationship between the command value for the torque of the second motor and the current of the first motor detected by the current sensor falls outside the predetermined range. Therefore, an abnormality in the drive control device can be detected when there is a risk of the vehicle's behavior becoming unstable.

In the tenth means,
The abnormality detection unit includes a first detection unit (52) that detects an abnormality related to the first motor and a second detection unit (62) that detects an abnormality related to the second motor,
a host control unit (70) that transmits both a first command value, which is a command value of a torque generated by the first motor, and a second command value, which is a command value of a torque generated by the second motor, to both the first detection unit and the second detection unit;
The first detection unit transmits the second command value received from the upper level control unit to the second detection unit;
The second detection unit transmits the first command value received from the upper level control unit to the first detection unit;
the first detection unit detects the abnormality in the drive control device when an absolute value of a difference between the first command value received from the higher-level control unit and the first command value received from the second detection unit is greater than a predetermined value;
The second detection unit detects the abnormality in the drive control device when the absolute value of the difference between the second command value received from the higher-level control unit and the second command value received from the first detection unit is greater than a predetermined value.

According to the above configuration, the first detection unit detects an abnormality related to the first motor, and the second detection unit detects an abnormality related to the second motor. The upper control unit transmits both a first command value, which is a command value for the torque generated by the first motor, and a second command value, which is a command value for the torque generated by the second motor, to both the first detection unit and the second detection unit. That is, the first detection unit receives not only the first command value but also the second command value, and the second detection unit receives not only the second command value but also the first command value. Then, the first detection unit transmits the second command value received from the upper control unit to the second detection unit, and the second detection unit transmits the first command value received from the upper control unit to the first detection unit.

Here, for example, if the first command value transmitted by the upper-level control unit is received correctly, the first command value received by the first detection unit from the upper-level control unit should match the first command value received by the first detection unit from the second detection unit. On the other hand, if the first command value received by the first detection unit from the upper-level control unit does not match the first command value received by the first detection unit from the second detection unit, there is a risk that the first command value transmitted by the upper-level control unit was not received correctly.

In this regard, the first detection unit detects an abnormality in the drive control device when the absolute value of the difference between the first command value received from the higher-level control unit and the first command value received from the second detection unit is greater than a predetermined value. The second detection unit detects an abnormality in the drive control device when the absolute value of the difference between the second command value received from the higher-level control unit and the second command value received from the first detection unit is greater than a predetermined value. Therefore, an abnormality in the drive control device can be detected when there is a risk that the torque command value transmitted by the higher-level control unit has not been received correctly.

In the eleventh means, the abnormality detection unit detects an abnormal state that is the abnormal state of the drive control device, and when the abnormality detection unit detects the abnormal state, the information output unit outputs the setting information to the torque setting unit as the information, which sets the upper torque values of the first motor and the second motor to the common predetermined value corresponding to the abnormal state.

The twelfth means is
A drive control device applied to a vehicle (10) including a first motor (21) that drives a first wheel (11) and a second motor (22) that drives a second wheel (12) independently of the first wheel,
A sensor (21a, 84) for detecting information related to the drive control device;
a torque setting unit (32, 132) that sets an upper limit value of torque that can be generated by the first motor and the second motor based on the information detected by the sensor;
an abnormality processing unit (35, 51, 52, 61, 62) that detects an abnormal state that is an abnormal state of the drive control device, and when the abnormal state is detected, outputs setting information to the torque setting unit as the information, the setting information setting the upper limit values of the torque of the first motor and the second motor to a common predetermined value corresponding to the abnormal state;
a drive control unit (33) that controls the torques generated by the first motor and the second motor so that they are equal to or less than the upper limit value set by the torque setting unit;
Equipped with.

According to the above configuration, an abnormal state in which the drive control device is abnormal is detected. Therefore, not only is an abnormality in the drive control device detected, but also an abnormal state in which the drive control device is abnormal is detected. Then, when an abnormal state is detected, setting information for setting the upper torque values of the first motor and the second motor to a common predetermined value according to the abnormal state is output as the information to the torque setting unit. Therefore, the upper torque values of the first motor and the second motor can be set to a common predetermined value according to the abnormal state. Therefore, the upper torque values of the first motor and the second motor can be set more appropriately, and unstable vehicle behavior and sudden deceleration of the vehicle can be further suppressed.

In the thirteenth means, the drive control unit is capable of executing a first control method and a second control method that are different from each other in controlling the torque generated by the first motor and the second motor, and the common predetermined value according to the abnormal state is set to a value according to whether the first control method or the second control method is being executed by the drive control unit when the abnormal state is detected.

According to the above configuration, the drive control unit can execute a first control method and a second control method that are different from each other in the method of controlling the torque generated by the first motor and the second motor. Therefore, the first control method and the second control method can be used depending on the running state of the vehicle. Here, when an abnormality occurs in the drive control device, the effect of the abnormality on the torque differs between the first control method and the second control method that are different from each other in the method of controlling the torque.

In this regard, the common predetermined value according to the abnormal state is set to a value according to whether the first control method or the second control method is being executed by the drive control unit when an abnormal state is detected. Therefore, the upper torque limit values of the first motor and the second motor can be appropriately set to a common predetermined value according to the effect of the abnormality on the torque in the first control method and the second control method.

Even if the torque command values generated by the first and second motors become abnormal, the danger to the vehicle is small as long as the torque does not increase erroneously.

In this regard, in the 14th means, when at least one of the first command value, which is a command value for the torque generated by the first motor, and the second command value, which is a command value for the torque generated by the second motor, becomes abnormal, the common predetermined value according to the abnormal state is set to the first command value or the second command value during a predetermined period prior to the abnormality.

According to the above configuration, even if at least one of the first command value and the second command value becomes abnormal, the upper torque value is set to the first command value or the second command value in a predetermined period before the abnormality occurred. Therefore, it is possible to prevent the torque generated by the first motor and the second motor from increasing erroneously, and the vehicle can be driven safely. Furthermore, even if the torque command value becomes abnormal, the upper torque value is not restricted as much as possible from the state before the abnormality occurred, and the vehicle can continue to drive.

In the fifteenth means, the sensor includes a current sensor (21b) that detects the current flowing through at least one of the first motor and the second motor, and the common predetermined value according to the abnormal state is set to a first command value that is a command value of the torque generated by the first motor or a second command value that is a command value of the torque generated by the second motor in a predetermined period prior to the time when the reference output, which is the output of the current sensor when the current is detected as zero, falls outside a predetermined range.

According to the above configuration, the sensor includes a current sensor that detects the current flowing through at least one of the first motor and the second motor. Even if the reference output, which is the output of the current sensor when the current is detected as 0, falls outside a predetermined range (hereinafter referred to as an "offset abnormality"), the detected current rarely changes suddenly. In this regard, when an offset abnormality occurs, the upper torque value is set to the first command value or the second command value in a predetermined period before the offset abnormality occurs. Therefore, the vehicle can be driven safely while continuing to drive without restricting the upper torque value as much as possible.

If a specific abnormality other than an offset abnormality occurs in the current sensor, the current may be erroneously detected, causing a sudden change in the torque generated by the first and second motors.

In this regard, in the sixteenth means, when a predetermined abnormality of the current sensor other than when the reference output falls outside the predetermined range is detected, the common predetermined value according to the abnormal state is set to a first corrected command value obtained by decreasing the first command value by a predetermined degree or a second corrected command value obtained by decreasing the second command value by a predetermined degree during a predetermined period prior to when the predetermined abnormality was detected.

According to the above configuration, when a predetermined abnormality other than an offset abnormality is detected, the upper limit values of the torque of the first motor and the second motor are set to a first corrected command value obtained by decreasing the first command value by a predetermined degree in a predetermined period prior to the detection of the predetermined abnormality, or to a second corrected command value obtained by decreasing the second command value by a predetermined degree. Therefore, when there is a risk of a sudden change in the torque generated by the first motor and the second motor, the vehicle can be driven more safely and can continue to drive.

In the seventeenth means, the sensor includes a voltage sensor (21d) that detects the voltage applied to at least one of the first motor and the second motor, and when an abnormality in the voltage sensor is detected, the common predetermined value according to the abnormal state is set to a first command value that is a command value for the torque generated by the first motor during a predetermined period prior to the detection of the abnormality in the voltage sensor, or a second command value that is a command value for the torque generated by the second motor.

According to the above configuration, the sensor includes a voltage sensor that detects the voltage applied to at least one of the first motor and the second motor. Even if an abnormality occurs in the voltage sensor, unless the current flowing through the first motor and the second motor changes suddenly, the torque rarely changes suddenly. In this regard, when an abnormality in the voltage sensor is detected, the upper torque limit value is set to the first command value or the second command value in a predetermined period before the abnormality in the voltage sensor is detected. Therefore, the vehicle can continue to run safely while limiting the upper torque limit value as much as possible.

If an abnormality occurs in the rotation angle sensor that detects the rotation angle of the motor, the motor cannot be appropriately controlled according to the rotation angle, and there is a risk that the torque generated by the first motor and the second motor will suddenly change.

In this regard, in the eighteenth means, the sensor includes a rotation angle sensor (21c) that detects the rotation angle of at least one of the first motor and the second motor, and the common predetermined value according to the abnormal state is set to 0 when the rotation angle sensor is abnormal. Therefore, when there is a risk that the motor cannot be appropriately controlled, the vehicle can be stopped exceptionally by prioritizing safety.

If there is an abnormality in at least one of the calculation functions of the torque setting unit and the drive control unit, the motor cannot be controlled properly, and there is a risk that the torque generated by the first motor and the second motor will suddenly change.

In this regard, in the 19th means, the common predetermined value according to the abnormal state is set to 0 when at least one of the calculation functions of the torque setting unit and the drive control unit is abnormal. Therefore, when there is a risk that the motor cannot be appropriately controlled, the vehicle can be stopped exceptionally by prioritizing safety.

FIG. 1 is a schematic diagram showing an electric vehicle. FIG. 1 is a block diagram showing the configurations of an EV-CU, an MG-CU, and an arbitration CU. 6 is a graph showing the relationship between a detected temperature value and an upper torque limit value. 4 is a map showing the relationship between a right torque command value, a left current detection value, and a normal determination range. FIG. 4 is a schematic diagram showing a temperature permission adjustment unit. 5 is a flowchart showing a procedure for detecting an abnormality and outputting temperature information. FIG. 13 is a schematic diagram showing a modified example of the temperature permission adjuster. 5 is a graph showing the relationship between vehicle speed, limit temperature information, and upper torque limit value. FIG. 13 is a block diagram showing a modified example of the arbitration CU. FIG. 13 is a block diagram showing a modified example of the drive control device.

First Embodiment
Hereinafter, a first embodiment embodied in a drive control device applied to an electric vehicle will be described with reference to the drawings.

As shown in FIG. 1, the electric vehicle 10 (vehicle) includes wheels 11-14, MGs (Motor Generators) 21, 22, INVs (Inverters) 25, 26, MG-CUs (Motor Generator Control Units) 30, 40, arbitration CUs (Control Units) 50, 60, and an EV-CU (Electric Vehicle Control Unit) 70.

The front left wheel 11 (first wheel) and right wheel 12 (second wheel) are driving wheels that drive the electric vehicle 10. The rear left and right wheels 13, 14 are driven wheels that move as the electric vehicle 10 travels. The wheels 11, 12 are steering wheels that move in accordance with steering wheel operation to change the direction of travel of the electric vehicle 10. The wheels 11, 12 are driven by MGs 21, 22, respectively.

MG21 (first motor) and MG22 (second motor) are three-phase AC motor generators (AC motors). MG21 and 22 have the function of driving the wheels 11 and 12 based on the power supplied from INV25 and 26, respectively, and the function of generating electricity based on the rotation of the wheels 11 and 12, respectively. MG21 and 22 drive the wheels 11 and 12 independently of each other. INV25 and 26 convert DC power supplied from a battery (not shown) into AC power and supply it to MG21 and 22, respectively. INV25 and 26 are circuits in which, for example, six switching elements are connected in a three-phase bridge. In addition, INV25 (first power conversion unit) and INV26 (second power conversion unit) convert the AC power supplied by the generation of MG21 and 22 into DC power and supply it to the battery, respectively. The drive states of INVs 25 and 26 are controlled by MG-CUs 30 and 40, respectively. Here, three-phase AC is described as an example, but the number of phases is not limited to three, and may be six, nine, etc.

The EV-CU 70 (high-level control unit) controls the entire electric vehicle 10. The EV-CU 70 is a microcomputer equipped with, for example, a CPU, RAM, ROM, an input/output interface, etc. The EV-CU 70 receives detection values from an accelerator sensor 81, a brake sensor 82, a steering angle sensor 83, a vehicle speed sensor 84, etc.

The accelerator sensor 81 detects the amount of depression of the accelerator pedal (not shown). The brake sensor 82 detects the amount of depression of the brake pedal (not shown). The steering angle sensor 83 (sensor) detects the steering angle of the steering wheel (not shown). The vehicle speed sensor 84 detects the speed (vehicle speed) of the electric vehicle 10.

The EV-CU 70 executes various controls of the electric vehicle 10 based on the detection values of the sensors 81 to 84. The EV-CU 70 generates command values for the torques to be generated by the MGs 21 and 22 (hereinafter referred to as "torque command values") based on the detection values of the sensors 81 to 84, and transmits the generated torque command values to the MG-CUs 30 and 40. The EV-CU 70 also transmits the torque command values for both the MGs 21 and 22 to the arbitration CUs 50 and 60. The MG-CUs 30 and 40 are microcomputers equipped with, for example, a CPU, RAM, ROM, an input/output interface, etc. The MG-CUs 30 and 40 control the drive state of the INVs 30 and 50, respectively, to control the drive and power generation of the MGs 21 and 22.

The arbitration CUs 50 and 60 are microcomputers equipped with, for example, a CPU, RAM, ROM, an input/output interface, etc. The arbitration CU 50 detects abnormalities in the MG 21, INV 25, MG-CU 30, and EV-CU 70, etc. The arbitration CU 60 detects abnormalities in the MG 22, INV 26, MG-CU 40, and EV-CU 70, etc. When the arbitration CU 50 detects an abnormality, it notifies the EV-CU 70 and arbitration CU 60 of the abnormality. When the arbitration CU 60 detects an abnormality, it notifies the EV-CU 70 and arbitration CU 50 of the abnormality.

The configuration of MG-CU30 and the configuration of MG-CU40 are basically the same, and the configuration of arbitration CU50 and the configuration of arbitration CU60 are basically the same. For this reason, the following explanation will be given using MG-CU30 and arbitration CU50 as examples.

As shown in FIG. 2, the EV-CU 70 includes a torque command value generating unit 71. The torque command value generating unit 71 generates torque command values for the MGs 21 and 22 based on the detection values of the sensors 81 to 84. The torque command value generating unit 71 transmits the torque command value for the MG 21 to the MG-CU 30.

The MG-CU 30 includes a torque command value receiving unit 31, a torque limiting unit 32, and a motor drive control unit 33. The torque command value receiving unit 31 has a function of receiving information transmitted from the EV-CU 70. The torque command value receiving unit 31 receives a torque command value (left torque command value) for the MG 21 from the EV-CU 70. The torque command value receiving unit 31 transmits the received torque command value to the torque limiting unit 32.

The torque limiting unit 32 (torque setting unit) limits (sets) the upper limit of the torque that the MG 21 can generate (hereinafter referred to as the "torque upper limit") based on the temperature of the coil of the MG 21 detected by the temperature sensor 21a (hereinafter referred to as the "coil temperature"). In detail, as shown in FIG. 3, when the coil temperature (temperature information, information on the drive control device) is less than T1, the torque limiting unit 32 sets the torque upper limit to torque Tr1. When the coil temperature is equal to or greater than T1, the torque limiting unit 32 reduces the torque upper limit as the coil temperature increases. When the coil temperature exceeds T2 (> T1), the torque limiting unit 32 sets the torque upper limit to 0. The torque limiting unit 32 limits the torque command value to the torque upper limit or less (upper limit guard) and transmits the limited torque command value to the motor drive control unit 33. Note that the torque value here is assumed to be an absolute value.

The motor drive control unit 33 (drive control unit) controls the drive state of INV25 so that the torque generated by MG21 becomes the torque command value based on the current of each phase of MG21 detected by current sensor 21b (sensor) and the rotation angle of MG21 detected by rotation angle sensor 21c. In other words, the motor drive control unit 33 controls the drive state of INV25 so that the torque generated by MG21 and MG22 becomes equal to or lower than the torque upper limit value.

The arbitration CU 50 (left arbitration CU) has a temperature permission adjustment unit 51 and an abnormality detection unit 52.

The abnormality detection unit 52 inputs the current (left current detection value) of MG21 detected by the current sensor 21b and the rotation angle of MG21 detected by the rotation angle sensor 21c. The abnormality detection unit 52 receives the detection values of various sensors input to the EV-CU 70 from the EV-CU 70. The abnormality detection unit 52 receives the torque command value (right torque command value) for MG22 from the EV-CU 70. The abnormality detection unit 52 detects abnormalities in MG21, INV25, MG-CU30, EV-CU70, etc. (drive control devices) based on the detection values of these sensors and the right torque command value. When the abnormality detection unit 52 detects an abnormality, it notifies the EV-CU 70 and the arbitration CU 60 of the abnormality. When the abnormality detection unit of the arbitration CU 60 (right arbitration CU) detects an abnormality, the abnormality detection unit 52 receives the abnormality from the arbitration CU 60.

More specifically, as shown in FIG. 4, the abnormality detection unit 52 predefines a predetermined range A in which the relationship between the right torque command value and the current flowing through MG21 is normal. The abnormality detection unit 52 detects an abnormality in the drive control device when the relationship between the right torque command value and the current detected by the current sensor 21b (left current detection value) falls outside the predetermined range A (abnormality determination). The predetermined range A has a predetermined width for the left current detection value, and is defined so that the left current detection value increases in proportion to the right torque command value. Here, the torque generated by MG21 changes depending on the current flowing through MG21, and if the torque difference between MG21 and MG22 increases, the behavior of the electric vehicle 10 may become unstable. For this reason, the predetermined range A is defined as an appropriate range of the current flowing through MG21 for the right torque command value.

When no abnormality is detected by the abnormality detection unit 52, the temperature permission adjustment unit 51 acquires the coil temperature from the temperature sensor 21a and outputs the acquired coil temperature to the torque limiting unit 32. That is, as shown in FIG. 5, the temperature permission adjustment unit 51 connects the temperature sensor 21a to the torque limiting unit 32.

On the other hand, when the abnormality detection unit 52 detects an abnormality or when an abnormality is received from the abnormality detection unit of the arbitration CU 60, the temperature permission adjustment unit 51 (information output unit) outputs the limit temperature information (setting information) that limits the upper limit value of the torque of the MGs 21 and 22 to a common predetermined value to the torque limiting unit 32 as the coil temperature (temperature information, information). That is, the temperature permission adjustment unit 51 switches the connection with the torque limiting unit 32 from the temperature sensor 21a to one of the dummy resistors r1 to r3 so that a coil temperature that is a predetermined temperature higher than the coil temperature detected by the temperature sensor 21a is output to the torque limiting unit 32. In addition, the temperature permission adjustment unit 51 transmits the coil temperature detected by the temperature sensor 21a to the abnormality detection unit 52, and the abnormality detection unit 52 transmits the received coil temperature to the arbitration CU 60. Note that the temperature permission adjustment unit 51 may be provided with a variable resistor rv instead of the dummy resistors r1 to r3, and adjust the variable resistor rv according to the coil temperature detected by the temperature sensor 21a.

The arbitration CU 60 has the same configuration as the arbitration CU 50. The arbitration CU 60 has a temperature permission adjustment unit 61 corresponding to the temperature permission adjustment unit 51, and an abnormality detection unit 62 (second detection unit) corresponding to the abnormality detection unit 52 (first detection unit). The MG-CU 40 and the arbitration CU 60 perform the same control as the MG-CU 30 and the arbitration CU 50 on the INV 26 and the MG 22, respectively. That is, the drive control device has a current sensor that detects the current flowing through the first motor, with one of the MG 21 (left motor) and the MG 22 (right motor) being the first motor and the other being the second motor. The drive control device predefines a predetermined range A in which the relationship between the command value of the torque generated by the second motor and the current flowing through the first motor is normal, and detects an abnormality in the drive control device when the relationship between the command value of the torque and the current detected by the current sensor falls outside the predetermined range A. The temperature sensor 21a, the torque limiting unit 32, the abnormality detection unit 52, and the temperature permission adjustment unit 51 constitute a drive control device.

Figure 6 is a flowchart showing the procedure for detecting an abnormality and outputting temperature information. This series of processes is repeatedly executed at a predetermined cycle by the left arbitration CU 50. Note that the right arbitration CU 60 also executes the same process by swapping left and right.

First, the vehicle speed and steering angle are obtained (S10). More specifically, the vehicle speed detected by the vehicle speed sensor 84 and the steering angle detected by the steering angle sensor 83 are obtained. Note that the vehicle speed may be obtained from the motor rotation angle information without using the vehicle speed sensor.

Next, the right torque command value and the left current detection value are acquired (S11). In more detail, the torque command value for MG22 (right torque command value) is received from the EV-CU 70, and the current of MG21 detected by the current sensor 21b (left current detection value) is input.

Next, based on the map shown in FIG. 4, it is determined whether or not an abnormality in the drive control device has been detected (S12). In more detail, as described above, if the relationship between the right torque command value and the left current detection value falls outside the specified range A, it is determined that an abnormality in the drive control device has been detected. In this determination, if it is determined that an abnormality in the drive control device has been detected (S12: YES), the EV-CU 70 and the right arbitration CU 60 are notified of the abnormality (S13). In addition, the coil temperature detected by the temperature sensor 21a is sent to the right arbitration CU 60. Then, the process proceeds to S15.

On the other hand, if it is determined in the judgment of S12 that an abnormality in the drive control device has not been detected (S12: NO), it is determined whether or not an abnormality has been received from the right arbitration CU 60 (S14). That is, the right arbitration CU 60 also executes the same process by swapping left and right, and determines whether or not an abnormality in the drive control device has been detected. Therefore, it is determined whether or not the right arbitration CU 60 has detected an abnormality in the drive control device and notified the left arbitration CU 50 of the abnormality.

If it is determined in step S14 that an abnormality has been received from the right arbitration CU 60 (S14: YES), limit temperature information is generated (S15). In more detail, as described above, the coil temperature (limit temperature information) that limits the upper torque limit value of MGs 21 and 22 to a common predetermined value is generated.

On the other hand, if it is determined in step S14 that no abnormality has been received from the right arbitration CU 60 (S14: NO), the detected temperature information is acquired (S16). In detail, the coil temperature (detected temperature information) detected by the temperature sensor 21a is input.

Then, the limit temperature information generated by the process of S15 or the detected temperature information obtained by the process of S16 is output to the torque limiting unit 32 of the MG-CU 50 (S17). After that, this series of processes is temporarily terminated (END).

The processes in S10 to S12 correspond to the processes performed by the anomaly detection unit 52, and the processes in S13, S15, and S17 correspond to the processes performed by the information output unit.

The present embodiment described above has the following advantages:

The abnormality detection unit 52 detects an abnormality in the drive control device. When an abnormality is detected by the abnormality detection unit 52, the temperature permission adjustment unit 51 outputs, as the coil temperature, limit temperature information for limiting the upper limit of the torque of MG21 and MG22 to a common predetermined value to the torque limit unit 32. As a result, the torque limit unit 32 limits the upper limit of the torque of MG21 and MG22 to a common predetermined value based on the limit temperature information. Therefore, the torque difference between MG21 and MG22 can be reduced, and the behavior of the electric vehicle 10 can be prevented from becoming unstable. Furthermore, instead of reducing the torque generated by MG21 and MG22, the upper limit of the torque of MG21 and MG22 is limited. Therefore, the torque of MG21 and MG22 can be prevented from suddenly decreasing, and the electric vehicle 10 can be prevented from suddenly decelerating. Moreover, by utilizing the torque limit unit 32 that is generally provided in the drive control device, the torque of MG21 and MG22 can be limited when an abnormality is detected, and the number of additional configurations can be prevented from increasing.

- Temperature sensor 21a detects the temperature of the coil of MG 21 as information related to the drive control device. Therefore, by utilizing the MG temperature sensor that is generally provided in the drive control device and a torque limiting unit that limits the upper torque value based on the MG temperature, the torque of MGs 21 and 22 can be limited when an abnormality is detected.

- The abnormality detection unit 52 predefines a predetermined range A within which the relationship between the command value of the torque generated by MG22 and the current flowing through MG21 is normal. The abnormality detection unit 52 detects an abnormality in the drive control device when the relationship between the command value of the torque of MG22 and the current of MG21 detected by the current sensor 21b falls outside the predetermined range A. Therefore, an abnormality in the drive control device can be detected when there is a risk that the behavior of the electric vehicle 10 will become unstable.

- When an abnormality is detected, the temperature permission adjustment unit 51 switches the connection with the torque limiting unit 32 from the temperature sensor 21a to one of the dummy resistors r1 to r3 so that a coil temperature that is a predetermined temperature higher than the coil temperature detected by the temperature sensor 21a is output to the torque limiting unit 32. Therefore, the torque upper limit can be limited according to the current coil temperature according to the relationship between the temperature detection value and the torque upper limit shown in FIG. 3, and a sudden decrease in the torque upper limit can be suppressed.

The above embodiment can also be modified as follows. The same parts as those in the above embodiment are given the same reference numerals and will not be described.

- Because it is rare for the temperature of MG21 and the temperature of MG22 to differ significantly, the temperature of only one of MG21 and MG22 may be detected by a temperature sensor. Then, the upper limit of the torque that MG21 and MG22 can generate may be limited based on the temperature (temperature information, information related to the drive control device) detected by one temperature sensor.

- When a specified abnormality is detected, the temperature permission adjustment unit 51 may switch the connection with the torque limiting unit 32 from the temperature sensor 21a to, for example, a dummy resistor r3 so that the coil temperature that limits the torque upper limit to the minimum torque at which the electric vehicle 10 can perform evacuation driving is output to the torque limiting unit 32. At that time, the connection with the torque limiting unit 32 may be switched from the temperature sensor 21a to the dummy resistors r1, r2, and r3 in that order. In other words, when a specified abnormality is detected, the temperature permission adjustment unit 51 may gradually limit the upper torque limits of the MGs 21 and 22 to a common specified value.

- As shown in FIG. 7, the temperature permission adjustment unit 51 can also connect at least one of the dummy resistors r11 to r13 to the torque limiting unit 32 in addition to the temperature sensor 21a so that, when an abnormality is detected, a coil temperature that is a predetermined temperature higher than the coil temperature detected by the temperature sensor 21a is output to the torque limiting unit 32. Furthermore, when an abnormality is detected, the temperature permission adjustment unit 51 can also output a digital signal corresponding to the detection value of the temperature sensor 21a to the torque limiting unit 32.

-If the left torque command value (first command value) transmitted by EV-CU70 (higher-level control unit) is received correctly, the left torque command value received by abnormality detection unit 52 (first detection unit) from EV-CU70 should match the left torque command value received by abnormality detection unit 52 from abnormality detection unit 62 (second detection unit). On the other hand, if the left torque command value received by abnormality detection unit 52 from EV-CU70 does not match the left torque command value received by abnormality detection unit 52 from abnormality detection unit 62, there is a risk that the left torque command value transmitted by EV-CU70 was not received correctly.

The abnormality detection unit 52 may detect an abnormality in the drive control device when the absolute value of the difference between the left torque command value received from the EV-CU 70 and the left torque command value received from the abnormality detection unit 62 is greater than a predetermined value. The abnormality detection unit 62 may also detect an abnormality in the drive control device when the absolute value of the difference between the right torque command value (second command value) received from the EV-CU 70 and the right torque command value received from the abnormality detection unit 52 is greater than a predetermined value. With this configuration, an abnormality in the drive control device can be detected when there is a risk that the torque command value transmitted by the EV-CU 70 has not been received correctly. The MG-CUs 30 and 40 can also calculate a checksum of the received torque command value and detect an abnormality in the drive control device when the checksums do not match. The EV-CU 70 can also detect an abnormality in the drive control device based on the detection values of various sensors.

- The extent to which the upper torque value of MGs 21, 22 should be restricted varies depending on the speed of electric vehicle 10 when an abnormality is detected. FIG. 8 is a graph showing the relationship between vehicle speed, restricted temperature information, and upper torque value. The restricted temperature information (coil temperature) increases as vehicle speed increases up to vehicle speed v2, and gradually decreases once vehicle speed v2 is exceeded. Vehicle speed v2 is a vehicle speed that is not realized on general roads but is realized on expressways, for example 100 km/h. Since expressways have gentle curves and are wide, the relationship between vehicle speed and restricted temperature information is set so as not to restrict the upper torque value too much.

Then, the temperature permission adjustment unit 51 calculates the limit temperature information according to the vehicle speed using the left graph in FIG. 8, and outputs the limit temperature information to the torque limit unit 32. The torque limit unit 32 sets the torque upper limit value according to the limit temperature information using the right graph in FIG. 8. For example, at vehicle speed v1, the torque upper limit value is set to torque Tr12, and at vehicle speed v2, the torque upper limit value is set to torque Tr11. That is, the temperature permission adjustment unit 51 sets the torque upper limit value (predetermined value) based on the speed of the electric vehicle 10. Therefore, the upper torque value of the MGs 21 and 22 can be limited to a predetermined value according to the speed of the electric vehicle 10 at the time of abnormality detection. Note that the vehicle speed corresponds to information related to the drive control device.

The temperature permission adjustment unit 51 can also set the torque upper limit value (predetermined value) based not only on the vehicle speed but also on the amount of depression (operation amount) of the accelerator pedal (accelerator operating member), the torque command value, and the steering angle. In this case, the greater the amount of depression of the accelerator pedal and the torque command value, the higher the limit temperature information (coil temperature). Also, the smaller the steering angle, the higher the limit temperature information (coil temperature). In other words, the smaller the steering angle, the closer the electric vehicle 10 is to traveling straight, so the smaller the torque upper limit value (predetermined value) should be. This makes it possible to prevent the vehicle's behavior from becoming unstable.

- If the coil temperature (temperature information, information) is not input from the temperature sensor 21a (sensor), it may not be possible to drive the MG21 (motor) properly. For this reason, as shown in FIG. 9, the MG-CU30 of the drive control device is provided with a torque limiting unit 132 that limits the upper limit of the torque that the MG21 can generate if the coil temperature is not input from the temperature sensor 21a. The MG-CU40 of the drive control device is provided with a torque limiting unit that limits the upper limit of the torque that the MG22 can generate if the coil temperature is not input from the temperature sensor that detects the temperature of the MG22.

The torque limiting unit 132 (torque setting unit) limits the upper limit of the torque that can be generated by MG21 and MG22 when the coil temperature is not input from the temperature sensor 21a, and the temperature permission adjustment unit 51 disconnects the temperature sensor 21a and the torque limiting unit 132 using the switch 53 when an abnormality is detected by the abnormality detection unit 52. This makes it possible to intentionally achieve a state in which the coil temperature is not input from the temperature sensor 21a to the torque limiting unit 132 when an abnormality is detected. Therefore, the torque of MG21 and 22 can be limited when an abnormality is detected by utilizing the torque limiting unit provided in the drive control device, which limits the upper limit of the torque of MG21 and 22 when the coil temperature is not input from the temperature sensor.

The drive control device may include a temperature sensor that detects the temperature of INV25 (power conversion unit), and the torque limiting unit 32 may limit the torque upper limit of MG21, 22 based on the temperature of INV25 detected by the temperature sensor. Similarly, the drive control device may include a temperature sensor that detects the temperature of INV26 (power conversion unit), and the torque limiting unit may limit the torque upper limit of MG21, 22 based on the temperature of INV26 detected by the temperature sensor. In this case, when an abnormality is detected by the abnormality detection unit 52, the temperature permission adjustment unit 51 may output limiting information (setting information) that limits (sets) the torque upper limit of MG21, 22 to a common predetermined value to the torque limiting unit as the temperature of INV25, 26. According to this configuration, the torque of MG21, 22 can be limited when an abnormality is detected by using the temperature sensor of INV25, 26 provided in the drive control device and the torque limiting unit that limits the torque upper limit based on the temperature of INV25, 26.

When a high voltage is applied between the coils of MG21, 22, the lower the atmospheric pressure, the more likely partial discharge will occur. For this reason, the drive control device may be provided with an atmospheric pressure sensor that detects atmospheric pressure, and may slow down the voltage rise caused by INV25, 26 as the detected atmospheric pressure decreases. In this case, the slower the voltage rise, the greater the temperature rise of INV25, 26. Therefore, when an abnormality is detected by the abnormality detection unit 52, the temperature permission adjustment unit 51 may output, as atmospheric pressure, limiting information (setting information) that limits (sets) the upper torque value of MG21, 22 to a common predetermined value to the torque limiting unit. With this configuration, when the drive control device is provided with an atmospheric pressure sensor and a torque limiting unit that limits the upper torque value based on atmospheric pressure, the torque of MG21, 22 can be limited by using them when an abnormality is detected.

The drive control device may include a temperature sensor that detects the temperature of the cooling water that cools MGs 21 and 22 and INVs 25 and 26, and the torque limiting unit 32 may limit the upper torque value of MGs 21 and 22 based on the temperature of the cooling water detected by the temperature sensor. In this case, when an abnormality is detected by the abnormality detection unit 52, the temperature permission adjustment unit 51 may output limiting information (setting information) that limits (sets) the upper torque value of MGs 21 and 22 to a common predetermined value to the torque limiting unit as the temperature of the cooling water. With this configuration, the torque of MGs 21 and 22 can be limited when an abnormality is detected by utilizing the cooling water temperature sensor provided in the drive control device and the torque limiting unit that limits the upper torque value based on the temperature of the cooling water.

- Only one common torque limiting unit may be provided for MG21 and MG22.

- MGs 21, 22, INVs 25, 26, MG-CUs 30, 40, and arbitration CUs 50, 60 may be provided for the left and right rear wheels 13, 14, respectively, instead of the left and right front wheels 11, 12. Also, MGs 21, 22, INVs 25, 26, MG-CUs 30, 40, and arbitration CUs 50, 60 may be provided for the left and right rear wheels 13, 14, respectively, in addition to the left and right front wheels 11, 12. Also, MGs 21, 22, INVs 25, 26, MG-CUs 30, 40, and arbitration CUs 50, 60 may be provided for the front and rear wheels 11, 13, respectively, instead of the left and right front wheels 11, 12. Also, instead of the front left and right wheels 11, 12, MGs 21, 22, INVs 25, 26, MG-CUs 30, 40, and arbitration CUs 50, 60 may be provided for the front left wheel 11 and the rear right wheel 14, respectively.

- The abnormality detection unit 52 may detect an abnormal state that is an abnormal state of the drive control device. When an abnormality state is detected by the abnormality detection unit 52, the temperature permission adjustment unit 51 (information output unit) may output to the torque limit unit 32 (torque setting unit) limit information (setting information) that sets the upper torque values of MG21 and MG22 to a common predetermined value according to the abnormal state.

According to the above configuration, not only is an abnormality in the drive control device detected, but the abnormality detection unit 52 detects an abnormal state in which the drive control device is abnormal. Then, when an abnormal state is detected, limiting information that sets the upper torque values of MG21 and MG22 to a common predetermined value according to the abnormal state is output to the torque limiting unit 32. Therefore, the upper torque values of MG21 and MG22 can be set to a common predetermined value according to the abnormal state. Therefore, the upper torque values of MG21 and MG22 can be set more appropriately, and the behavior of the electric vehicle 10 can be more appropriately prevented from becoming unstable and the electric vehicle 10 can be further prevented from suddenly decelerating.

- As shown in FIG. 10, the MG-CU 30 may be equipped with an abnormality processing unit 35. The abnormality processing unit 35 detects an abnormal state, which is an abnormal state of the drive control device, and when an abnormal state is detected, outputs limiting information to the torque limiting unit 32 to set the upper torque values of MG 21 and MG 22 to a common predetermined value according to the abnormal state. In this case, the arbitration CUs 50 and 60 can be omitted.

According to the above configuration, when an abnormal condition is detected by the abnormality processing unit 35, the abnormality processing unit 35 outputs limiting information to the torque limiting unit 32, which sets the upper torque limit values of MG21 and MG22 to a common predetermined value according to the abnormal condition. In this case, too, the same effect as above can be achieved.

- The motor drive control unit 33 can execute a first control method and a second control method which are different methods for controlling the torque generated by MG21 and MG22, and the common predetermined value according to the abnormal state may be set to a value according to whether the first control method or the second control method is being executed by the motor drive control unit 33 when an abnormal state is detected. For example, the first control method is a control method in which the voltage applied to MG21, 22 is feedback-controlled by PWM control so that the current detected by the current sensor 21b (22b) becomes the target current. In addition, the second control method is a control method in which the rotation angle at which a square wave voltage is applied to MG21, 22 is controlled by square wave control.

According to the above configuration, the motor drive control unit 33 can execute a first control method and a second control method that are different from each other in the method of controlling the torque generated by MG21 and MG22. Therefore, the first control method and the second control method can be used depending on the running state of the electric vehicle 10. Here, the first control method and the second control method that are different from each other in the method of controlling torque have different influences (contributions) of an abnormality on the torque when an abnormality occurs in the drive control device. For example, when an abnormality occurs in the current sensor 21b (22b), there is a risk of a sudden change in torque in PWM control, whereas a sudden change in torque is unlikely to occur in square wave control.

In this regard, the common predetermined value according to the abnormal state is set to a value (value according to the effect) according to whether the first control method or the second control method is being executed by the motor drive control unit 33 when an abnormal state is detected. Therefore, the upper torque limit values of MG21 and MG22 can be appropriately set to a common predetermined value according to the effect that the abnormality has on the torque in the first control method and the second control method.

・Even if the command values of the torque generated by MG21 and MG22 become abnormal, the danger to the electric vehicle 10 is small if the torque does not increase erroneously. Therefore, the common predetermined value according to the abnormal state may be set to the first command value or the second command value in a predetermined period before the abnormality occurs when at least one of the left torque command value (first command value) which is the command value of the torque generated by MG21 and the right torque command value (second command value) which is the command value of the torque generated by MG22 becomes abnormal. Whether or not the left torque command value has become abnormal can be determined, for example, as described above, by whether or not the absolute value of the difference between the left torque command value received from the EV-CU70 and the left torque command value received from the arbitration CU60 is greater than a predetermined value. The predetermined period before the abnormality can be, for example, the period immediately before the abnormality occurs, or a period several seconds (slightly before) before the abnormality occurs. The same applies to the "predetermined period before the case" in the following.

According to the above configuration, even if at least one of the left command value and the right torque command value becomes abnormal, the upper torque limit is set to the left torque command value or the right torque command value in a predetermined period prior to the abnormality. This makes it possible to prevent the torque generated by MG21 and MG22 from increasing erroneously, allowing the electric vehicle 10 to run safely. Furthermore, even if the torque command value becomes abnormal, the upper torque limit is not restricted as much as possible from the state prior to the abnormality, allowing the electric vehicle 10 to continue running.

- The common predetermined value according to the abnormal state may be set to the left torque command value or the right torque command value in a predetermined period prior to the reference output (0 point), which is the output of the current sensor 21b (22b) when the current is detected as 0, falling outside the predetermined range. For example, the current sensor 21b (22b) outputs a voltage of 0 to 5 V in response to a current of -500 A to 500 A. In this case, the reference output, which is the output of the current sensor 21b (22b) when the current is detected as 0 A, is 2.5 V. The predetermined range is set to, for example, 2.0 V to 3.0 V.

Here, even if the reference output of the current sensor 21b falls outside the specified range (hereinafter referred to as "offset abnormality"), it is rare for the detected current to suddenly change. For this reason, when an offset abnormality occurs, the upper torque limit value may be set to the left torque command value or the right torque command value in a specified period before the offset abnormality occurred. With this configuration, the electric vehicle 10 can be driven safely while continuing to run without restricting the upper torque limit value as much as possible.

- If a predetermined abnormality occurs in the current sensor 21b other than the offset abnormality, the current may be erroneously detected, causing a sudden change in the torque generated by the MG21 and MG22. Examples of the predetermined abnormality include a broken wire in the current sensor 21b, a short circuit in the current sensor 21b, and a gain abnormality in the current sensor 21b. Therefore, the common predetermined value according to the abnormal state may be set to a first correction command value obtained by decreasing the left torque command value by a predetermined degree or a second correction command value obtained by decreasing the right torque command value by a predetermined degree in a predetermined period prior to the detection of the predetermined abnormality when a predetermined abnormality in the current sensor 21b other than when the reference output is out of the predetermined range is detected. The first correction command value (second correction command value) may be, for example, a value obtained by dividing the left torque command value (right torque command value) by 1/2 or 1/3, or a value obtained by subtracting a predetermined value from the left torque command value (right torque command value).

According to the above configuration, when a specified abnormality other than an offset abnormality is detected, the upper torque limit values of MG21 and MG22 are set to a first corrected command value that is a specified degree smaller than the left torque command value or a specified degree smaller than the right torque command value during a specified period prior to the detection of the specified abnormality. Therefore, when there is a risk of a sudden change in the torque generated by MG21 and MG22, the electric vehicle 10 can be driven more safely and can continue to drive.

- The drive control device includes a voltage sensor 21d (22d) that detects the voltage applied to at least one of MG21 and MG22, and when an abnormality in the voltage sensor 21d is detected, the common predetermined value according to the abnormal state may be set to the left torque command value or the right torque command value for a predetermined period prior to when the abnormality in the voltage sensor 21d is detected.

Even if an abnormality occurs in the voltage sensor 21d, unless the current flowing through MG21 and MG22 changes suddenly, the torque rarely changes suddenly. In this regard, when an abnormality in the voltage sensor 21d is detected, the upper torque limit value is set to the left torque command value or the right torque command value in a predetermined period before the abnormality in the voltage sensor 21d was detected. Therefore, the electric vehicle 10 can continue to run safely while limiting the upper torque limit as much as possible.

- If an abnormality occurs in the rotation angle sensor 21c (22c), it may become impossible to appropriately control MG21 and MG22 according to the rotation angle, and the torque generated by MG21 and MG22 may change suddenly. Therefore, the common predetermined value according to the abnormal state may be set to 0 when the rotation angle sensor 21c (22c) is abnormal. With this configuration, if there is a risk that MG21 and MG22 cannot be appropriately controlled, the electric vehicle 10 can be stopped exceptionally by prioritizing safety. Note that when setting the common predetermined value according to the abnormal state to 0, the common predetermined value may be gradually brought closer to 0.

- If at least one of the calculation functions of the torque limiting unit 32 and the motor drive control unit 33 is abnormal, the MG21 and MG22 cannot be controlled appropriately, and the torque generated by the MG21 and MG22 may change suddenly. An abnormality in the calculation function may be, for example, an abnormality in the microcomputer (calculator) constituting the torque limiting unit 32 and the motor drive control unit 33. Therefore, the common predetermined value corresponding to the abnormal state may be set to 0 when at least one of the calculation functions of the torque limiting unit 32 and the motor drive control unit 33 is abnormal. With this configuration, if there is a risk that the MG21 and MG22 cannot be controlled appropriately, the electric vehicle 10 can be stopped exceptionally by prioritizing safety. When setting the common predetermined value corresponding to the abnormal state to 0, the common predetermined value may be gradually brought closer to 0.

The above drive control devices can be applied not only to the electric vehicle 10 but also to a hybrid vehicle (vehicle) that has an engine in addition to the MGs 21 and 22 as a power source. In addition, the electric vehicle is not limited to one that uses a battery as an energy source, and may be a fuel cell vehicle (FCV) that uses a fuel cell as an energy source.

10...electric vehicle, 11...wheel, 12...wheel, 13...wheel, 14...wheel, 21...MG, 21a...temperature sensor, 22...MG, 30...MG-CU, 32...torque limiting unit, 40...MG-CU, 50...arbitration CU, 51...temperature permission adjustment unit, 52...abnormality detection unit, 60...arbitration CU, 61...temperature permission adjustment unit, 62...abnormality detection unit, 132...torque limiting unit.

Claims (20)

A drive control device applied to a vehicle (10) including a first motor (21) that drives a first wheel (11) and a second motor (22) that drives a second wheel (12) independently of the first wheel,
A sensor (21a, 84) for detecting information related to the drive control device;
a torque setting unit (32, 132) that sets an upper limit value of torque that can be generated by the first motor and the second motor based on the information detected by the sensor;
An abnormality detection unit (52, 62) that detects an abnormality in the drive control device;
an information output unit (51, 61) configured to output, when the abnormality is detected by the abnormality detection unit, setting information for setting upper limits of the torque of the first motor and the second motor to a common predetermined value as the information to the torque setting unit;
a drive control unit (33) that controls the torques generated by the first motor and the second motor so that they are equal to or less than the upper limit value set by the torque setting unit;
Equipped with
the torque setting unit sets an upper limit value of the torque that can be generated by the first motor and the second motor when the information is not input from the sensor;
The information output unit disconnects the sensor from the torque setting unit when the abnormality is detected by the abnormality detection unit . A current sensor (21b) is provided for detecting a current flowing through the first motor,
2. The vehicle drive control device according to claim 1, wherein the abnormality detection unit predetermines a predetermined range within which a relationship between a command value for the torque generated by the second motor and a current flowing through the first motor is normal, and detects the abnormality in the drive control device when the relationship between the command value and the current detected by the current sensor falls outside the predetermined range. A drive control device applied to a vehicle (10) including a first motor (21) that drives a first wheel (11) and a second motor (22) that drives a second wheel (12) independently of the first wheel,
A sensor (21a, 84) for detecting information related to the drive control device;
a torque setting unit (32, 132) that sets an upper limit value of torque that can be generated by the first motor and the second motor based on the information detected by the sensor;
An abnormality detection unit (52, 62) that detects an abnormality in the drive control device;
an information output unit (51, 61) configured to output, when the abnormality is detected by the abnormality detection unit, setting information for setting upper limits of the torque of the first motor and the second motor to a common predetermined value as the information to the torque setting unit;
a drive control unit (33) that controls the torques generated by the first motor and the second motor so that they are equal to or less than the upper limit value set by the torque setting unit;
A current sensor (21b) for detecting a current flowing through the first motor;
Equipped with
The abnormality detection unit predetermines a predetermined range within which the relationship between a command value for the torque generated by the second motor and the current flowing through the first motor is normal, and detects the abnormality in the drive control device when the relationship between the command value and the current detected by the current sensor falls outside the predetermined range. The abnormality detection unit includes a first detection unit (52) that detects an abnormality related to the first motor and a second detection unit (62) that detects an abnormality related to the second motor,
a host control unit (70) that transmits both a first command value, which is a command value of a torque generated by the first motor, and a second command value, which is a command value of a torque generated by the second motor, to both the first detection unit and the second detection unit;
The first detection unit transmits the second command value received from the upper level control unit to the second detection unit;
The second detection unit transmits the first command value received from the upper level control unit to the first detection unit;
the first detection unit detects the abnormality in the drive control device when an absolute value of a difference between the first command value received from the higher-level control unit and the first command value received from the second detection unit is greater than a predetermined value;
4. The drive control device for a vehicle according to claim 1, wherein the second detection unit detects the abnormality in the drive control device when an absolute value of a difference between the second command value received from the higher-level control unit and the second command value received from the first detection unit is greater than a predetermined value. A drive control device applied to a vehicle (10) including a first motor (21) that drives a first wheel (11) and a second motor (22) that drives a second wheel (12) independently of the first wheel,
A sensor (21a, 84) for detecting information related to the drive control device;
a torque setting unit (32, 132) that sets an upper limit value of torque that can be generated by the first motor and the second motor based on the information detected by the sensor;
An abnormality detection unit (52, 62) that detects an abnormality in the drive control device;
an information output unit (51, 61) configured to output setting information for setting upper limits of the torque of the first motor and the second motor to a common predetermined value as the information to the torque setting unit when the abnormality is detected by the abnormality detection unit;
a drive control unit (33) that controls the torques generated by the first motor and the second motor so that they are equal to or less than the upper limit value set by the torque setting unit;
Equipped with
The abnormality detection unit includes a first detection unit (52) that detects an abnormality related to the first motor and a second detection unit (62) that detects an abnormality related to the second motor,
a host control unit (70) that transmits both a first command value, which is a command value of a torque generated by the first motor, and a second command value, which is a command value of a torque generated by the second motor, to both the first detection unit and the second detection unit;
The first detection unit transmits the second command value received from the upper level control unit to the second detection unit;
The second detection unit transmits the first command value received from the upper level control unit to the first detection unit;
the first detection unit detects the abnormality in the drive control device when an absolute value of a difference between the first command value received from the higher-level control unit and the first command value received from the second detection unit is greater than a predetermined value;
A drive control device for a vehicle, wherein the second detection unit detects the abnormality in the drive control device when the absolute value of the difference between the second command value received from the higher-level control unit and the second command value received from the first detection unit is greater than a predetermined value. The abnormality detection unit detects an abnormal state that is the abnormal state of the drive control device,
6. The drive control device for a vehicle according to claim 1, wherein, when the abnormality detection unit detects the abnormality state, the information output unit outputs, as the information to the torque setting unit, the setting information for setting upper limits of the torque of the first motor and the second motor to the common predetermined value corresponding to the abnormality state. A drive control device applied to a vehicle (10) including a first motor (21) that drives a first wheel (11) and a second motor (22) that drives a second wheel (12) independently of the first wheel,
A sensor (21a, 84) for detecting information related to the drive control device;
a torque setting unit (32, 132) that sets an upper limit value of torque that can be generated by the first motor and the second motor based on the information detected by the sensor;
An abnormality detection unit (52, 62) that detects an abnormality in the drive control device;
an information output unit (51, 61) configured to output setting information for setting upper limits of the torque of the first motor and the second motor to a common predetermined value as the information to the torque setting unit when the abnormality is detected by the abnormality detection unit;
a drive control unit (33) that controls the torques generated by the first motor and the second motor so that they are equal to or less than the upper limit value set by the torque setting unit;
Equipped with
The abnormality detection unit detects an abnormal state that is the abnormal state of the drive control device,
a torque setting unit that outputs, when the abnormality detection unit detects an abnormal state, the setting information that sets upper limit values of the torque of the first motor and the second motor to the common predetermined value corresponding to the abnormal state as information to the torque setting unit. A drive control device applied to a vehicle (10) including a first motor (21) that drives a first wheel (11) and a second motor (22) that drives a second wheel (12) independently of the first wheel,
A sensor (21a, 84) for detecting information related to the drive control device;
a torque setting unit (32, 132) that sets an upper limit value of torque that can be generated by the first motor and the second motor based on the information detected by the sensor;
an abnormality processing unit (35, 51, 52, 61, 62) that detects an abnormal state that is an abnormal state of the drive control device, and when the abnormal state is detected, outputs setting information to the torque setting unit as the information, the setting information setting the upper limit values of the torque of the first motor and the second motor to a common predetermined value corresponding to the abnormal state;
a drive control unit (33) that controls the torques generated by the first motor and the second motor so that they are equal to or less than the upper limit value set by the torque setting unit;
A vehicle drive control device comprising: the drive control unit is capable of executing a first control method and a second control method which are different from each other in controlling torque generated by the first motor and the second motor,
The vehicle drive control device according to any one of claims 6 to 8, wherein the common predetermined value according to the abnormal condition is set to a value according to whether the first control method or the second control method is being executed by the drive control unit when the abnormal condition is detected. 10. The drive control device for a vehicle according to claim 6, wherein, when at least one of a first command value, which is a command value for a torque generated by the first motor, and a second command value, which is a command value for a torque generated by the second motor, becomes abnormal, the common predetermined value corresponding to the abnormal state is set to the first command value or the second command value in a predetermined period prior to the abnormality. The sensor includes a current sensor (21b) that detects a current flowing through at least one of the first motor and the second motor,
The drive control device for a vehicle according to any one of claims 6 to 10, wherein, when a reference output, which is the output of the current sensor when the current is detected as 0, falls outside a predetermined range, the common predetermined value according to the abnormal state is set to a first command value which is a command value of the torque generated by the first motor or a second command value which is a command value of the torque generated by the second motor during a predetermined period prior to the reference output falling outside the predetermined range. 12. The vehicle drive control device according to claim 11, wherein, when a predetermined abnormality of the current sensor other than a case where the reference output falls outside the predetermined range is detected, the common predetermined value according to the abnormal state is set to a first corrected command value obtained by decreasing the first command value by a predetermined degree or a second corrected command value obtained by decreasing the second command value by a predetermined degree in a predetermined period prior to the detection of the predetermined abnormality. The sensor includes a voltage sensor (21d) that detects a voltage applied to at least one of the first motor and the second motor,
A drive control device for a vehicle as described in any one of claims 6 to 12, wherein the common predetermined value according to the abnormal state is set to a first command value that is a command value of the torque generated by the first motor during a predetermined period prior to the detection of the abnormality in the voltage sensor when an abnormality in the voltage sensor is detected, or a second command value that is a command value of the torque generated by the second motor. The sensor includes a rotation angle sensor (21c) that detects a rotation angle of at least one of the first motor and the second motor,
The drive control device for a vehicle according to any one of claims 6 to 13 , wherein the common predetermined value according to the abnormal state is set to 0 when the rotation angle sensor is abnormal. The vehicle drive control device according to any one of claims 6 to 14 , wherein the common predetermined value according to the abnormal state is set to 0 when at least one calculation function of the torque setting unit and the drive control unit is abnormal. The drive control device for a vehicle according to any one of claims 1 to 15 , wherein the sensor detects temperature information as the information. The drive control device for a vehicle according to claim 16 , wherein the temperature information is a temperature of at least one of the first motor and the second motor. the first motor and the second motor are AC motors,
a first power conversion unit (INV25) that converts supplied DC power into AC power and supplies the AC power to the first motor; and a second power conversion unit (INV26) that converts supplied DC power into AC power and supplies the AC power to the second motor,
The drive control device for a vehicle according to claim 16 , wherein the sensor detects a temperature of at least one of the first power conversion unit and the second power conversion unit as the temperature information. The drive control device for a vehicle according to claim 16 , wherein the sensor detects a temperature of a cooling water as the temperature information. The vehicle drive control device according to any one of claims 1 to 15 , wherein the sensor (84) detects a speed of the vehicle as the information.

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