WO2021182136A1 - Vehicle control device - Google Patents

Abstract

A vehicle control device (60) for controlling an electric motor (20) that transmits torque to the drive wheels of a vehicle, said control device being provided with torque sensors (51, 52) for detecting torque applied to a driveshaft that transmits torque from the electric motor to the drive wheels, and a motor control unit (631) for controlling the electric motor on the basis of the output torque of the electric motor and the torque detected by the torque sensors.

Description

Vehicle control device Cross-reference of related applications

This application is based on Japanese Patent Application No. 2020-0441669 filed on March 13, 2020, claiming the benefit of its priority, and the entire contents of the patent application Incorporated herein by reference.

This disclosure relates to a vehicle control device.

Conventionally, there is a vehicle control device described in Patent Document 1 below. This vehicle is a so-called electric vehicle that travels by transmitting the power of an electric motor to the drive wheels. The control device sets a torque command value, which is a target value of the output torque of the electric motor, based on various state quantities of the vehicle. The control device calculates the torque command value after filtering by applying a filtering process to the torque command value to suppress the vibration of the drive shaft connected to the drive wheels. Further, the control device calculates an estimated value of the angular velocity of the electric motor in the process of calculating the torque command value after the filter. The control device calculates the torque correction value based on the difference between the calculated estimated angular velocity of the electric motor and the actual angular velocity of the electric motor, and adds the calculated torque correction value to the filtered torque command value. The final torque command value is obtained by doing so. The control device feedback-controls the output torque of the electric motor based on the obtained final torque command value.

JP-A-2017-225278

In a vehicle as described in Patent Document 1, when the electric motor outputs a positive torque, that is, when the vehicle is traveling forward, the traveling road surface of the vehicle starts from a road surface state having a low road friction coefficient. When the road surface condition changes to a high road friction coefficient, a negative torque is applied to the drive wheels. Similarly, when the drive wheels get over a step while the vehicle is traveling forward, or when braking torque is applied to the wheels by a friction braking device or the like, negative torque is applied to the wheels. When such a negative torque is applied to the drive wheels, the drive shaft connected to the drive wheels may be twisted. As a result of the twisting of the drive shaft, the angular velocity of the electric motor changes. When the angular velocity of the electric motor changes, the control device described in Patent Document 1 described above corrects the torque command value based on the change in the angular velocity of the electric motor, so that the output torque of the electric motor is feedback-controlled. It has become so.

On the other hand, in the situation where the above negative torque is applied to the drive wheels, the angular velocity of the electric motor does not change unless the drive shaft is completely twisted. Therefore, in the case of a configuration in which the output torque of the electric motor is feedback-controlled based on the angular velocity of the electric motor as in the control device described in Patent Document 1, from the time when the drive shaft starts to twist until the drive shaft is completely twisted. The timing at which the correction of the torque command value is started will be delayed by the period of. Therefore, it is difficult to avoid twisting of the drive shaft with the control device described in Patent Document 1. Once the drive shaft is twisted, vibration occurs as the twist is released. When the vibration of the drive shaft is transmitted to the vehicle body or the like, the entire vehicle may vibrate.

An object of the present disclosure is to provide a vehicle control device capable of suppressing vehicle vibration caused by twisting of a drive shaft.

The vehicle control device according to one aspect of the present disclosure is a control device that controls an electric motor that transmits torque to the drive wheels of the vehicle, and detects torque applied to a drive shaft that transmits torque of the electric motor to the drive wheels. It includes a torque sensor and a motor control unit that controls the electric motor based on the torque detected by the torque sensor and the output torque of the electric motor.

According to this configuration, when a torque that causes twisting is applied to the drive shaft due to a disturbance applied to the drive wheels, the change in the torque is detected by the torque sensor. As a result, the twist of the drive shaft can be detected by the change in torque before the drive shaft is completely twisted. Therefore, by controlling the electric motor based on the torque detected by the torque sensor and the output torque of the electric motor, the electric motor is so that the twist is removed from the drive shaft before the drive shaft is completely twisted. Can be controlled. Therefore, since it is possible to prevent the drive shaft from being completely twisted, it is possible to suppress the vibration of the vehicle caused by the twisting of the drive shaft.

FIG. 1 is a block diagram showing a schematic configuration of a vehicle according to the first embodiment. FIG. 2 is a block diagram showing an electrical configuration of the vehicle of the first embodiment. FIG. 3 is a flowchart showing a procedure of processing executed by the motor control unit of the first embodiment. FIG. 4 is a timing chart showing changes in the torque detection value Td of the drive shaft, the output torque Tm of the motor generator, and the final torque command value T * in the vehicle of the first embodiment. FIG. 5 is a block diagram showing a schematic configuration of a vehicle according to a first modification of the first embodiment. FIG. 6 is a flowchart showing a procedure of processing executed by the motor control unit of the second modification of the first embodiment. FIG. 7 is a block diagram showing a procedure for calculating the final torque command value by the motor control unit of the second embodiment. FIG. 8 is a block diagram showing a schematic configuration of a vehicle of another embodiment.

Hereinafter, an embodiment of the vehicle control device will be described with reference to the drawings. In order to facilitate understanding of the description, the same components are designated by the same reference numerals as much as possible in each drawing, and duplicate description is omitted.
First, a schematic configuration of a vehicle on which the control device of the present embodiment is mounted will be described.

As shown in FIG. 1, the vehicle 10 of the present embodiment includes a motor generator 20, an inverter device 21, a battery 22, and a differential device 23. The vehicle 10 is a so-called electric vehicle that uses the motor generator 20 as a power source for traveling.
The inverter device 21 converts the DC power stored in the battery 22 into three-phase AC power, and supplies the converted three-phase AC power to the motor generator 20.

The motor generator 20 operates as an electric motor and a generator. When operating as an electric motor, the motor generator 20 is driven based on the three-phase AC power supplied from the inverter device 21. The driving force of the motor generator 20 is transmitted to the right front wheel 11 and the left front wheel 12 of the vehicle 10 via the differential device 23 and the drive shaft 24, so that the right front wheel 11 and the left front wheel 12 rotate, and the vehicle 10 runs. do. In the vehicle 10, the right front wheel 11 and the left front wheel 12 function as driving wheels, and the right rear wheel 13 and the left rear wheel 14 function as driven wheels. Hereinafter, the right front wheel 11 is referred to as a "right drive wheel 11", the left front wheel 12 is referred to as a "left drive wheel 12", and the right front wheel 11 and the left front wheel 12 are collectively referred to as " drive wheels 11 and 12". In this embodiment, the motor generator 20 corresponds to an electric motor.

The motor generator 20 operates as a generator when the vehicle is braked. Specifically, when the vehicle 10 is braked, the braking force applied to the drive wheels 11 and 12 is input to the motor generator 20 via the drive shaft 24 and the differential device 23. The motor generator 20 generates electricity based on the power input back from the drive wheels 11 and 12. The three-phase AC power generated by the motor generator 20 is converted into DC power by the inverter device 21 and charged into the battery 22.

The differential device 23 is composed of a combination of a plurality of rotating elements, and absorbs the difference in rotational speed when there is a difference in the rotational speeds of the right drive wheel 11 and the left drive wheel 12. At the same time, the driving force transmitted from the motor generator 20 is distributed and transmitted to the right driving wheel 11 and the left driving wheel 12.

Friction braking devices 31 to 34 are provided on the wheels 11 to 14 of the vehicle 10, respectively. The friction braking devices 31 to 34 are devices that apply a braking force to the wheels 11 to 14 by applying a frictional force to the rotating body that rotates integrally with the wheels 11 to 14.
Next, the electrical configuration of the vehicle 10 will be described.

As shown in FIG. 2, the vehicle 10 includes wheel speed sensors 41 to 44, an acceleration sensor 45, a yaw rate sensor 46, a brake switch 47, an accelerator opening sensor 48, and torque sensors 51 and 52. ing. Further, the vehicle 10 has an ESC-ECU (Electronic Stability Control-Electronic Control Unit) 61, an EV-ECU (Electric Vehicle-Electronic Control Unit) 62, and an MG-ECU (Motor Generator-Electronic) as parts for performing various controls. It has a Control Unit) 63. Each ECU 61 to 63 is mainly composed of a microcomputer having a CPU, a memory, or the like. In this embodiment, the control device 60 is configured by the ECUs 61 to 63.

As shown in FIG. 1, the wheel speed sensors 41 to 44 are provided on the wheels 11 to 14, respectively. The wheel speed sensors 41 to 44 detect the wheel speeds ωw11 to ωw14, which are the rotational speeds of the wheels 11 to 14, respectively, and the ESC-ECU61 shown in FIG. 2 sends a signal corresponding to the detected wheel speeds ωw11 to ωw14. Output to.

The acceleration sensor 45 detects the lateral acceleration of the vehicle 10 and outputs a signal corresponding to the detected lateral acceleration to the ESC-ECU 61.
The yaw rate sensor 46 detects the yaw rate, which is the angular velocity around the vertical axis of the vehicle 10, and outputs a signal corresponding to the detected yaw rate to the ESC-ECU 61.

The brake switch 47 detects whether or not the brake pedal of the vehicle 10 has been depressed, and outputs a signal according to the detection result to the ESC-ECU 61.
The accelerator opening sensor 48 detects the accelerator opening, which is the amount of depression of the accelerator pedal of the vehicle 10, and outputs a signal corresponding to the detected accelerator opening to the EV-ECU 62.

As shown in FIG. 1, torque sensors 51 and 52 are provided at both ends of the drive shaft 24, respectively. One torque sensor 51 is provided in the vicinity of one end 241 of the drive shaft 24 connected to the right drive wheel 11, and detects the torque applied to the one end 241 of the drive shaft 24. The other torque sensor 52 is provided in the vicinity of the other end 242 of the drive shaft 24 connected to the left drive wheel 12, and detects the torque applied to the other end 242 of the drive shaft 24. The torque sensors 51 and 52 shall detect torque by sensors such as a magnetostrictive type, a strain gauge type, and a capacitance type. As shown in FIG. 2, the torque sensors 51 and 52 output a signal corresponding to the detected torque to the MG-ECU 63 of the inverter device 21.

The ESC-ECU 61 executes vehicle behavior control for stabilizing the posture of the vehicle 10 by executing a program stored in advance in the memory. The vehicle behavior control is, for example, a sideslip prevention control that suppresses the sideslip of the vehicle 10. Specifically, does the ESC-ECU 61 cause oversteer or understeer in the vehicle 10 based on the lateral acceleration of the vehicle 10 detected by the acceleration sensor 45 and the yaw rate of the vehicle 10 detected by the yaw rate sensor 46? Judge whether or not. When oversteer or understeer is detected, the ESC-ECU 61 automatically adjusts the posture of the vehicle 10 so as to approach the ideal running state by applying a braking force to each of the wheels 11 to 14 by the friction braking devices 31 to 34. Control.

Further, the ESC-ECU 61 is a brake that applies a braking force to the wheels 11 to 14 by the friction braking devices 31 to 34 when it detects that the brake pedal of the vehicle 10 is depressed based on the output signal of the brake switch 47. It also executes control and the like.
The MG-ECU 63 is provided in the inverter device 21. The MG-ECU 63 controls the operation of the motor generator 20 by executing a program stored in advance in the memory. The MG-ECU 63 has a torque calculation unit 630 and a motor control unit 631.

The torque calculation unit 630 calculates the torque of one end 241 of the drive shaft 24 based on the output signal of the torque sensor 51, and calculates the torque of the other end 242 of the drive shaft 24 based on the output signal of the torque sensor 52. do.
The motor control unit 631 controls the motor generator 20 by driving the inverter device 21 based on the request from the EV-ECU 62. When the MG-ECU 63 receives, for example, a torque command value Tb * which is a command value of the output torque of the motor generator 20 from the EV-ECU 62, the MG-ECU 63 is required to output power corresponding to the torque command value Tb * from the motor generator 20. The energization control value of the motor generator 20 is calculated, and the inverter device 21 is driven based on the calculated energization control value. Further, the MG-ECU 63 drives the inverter device 21 so that the electric power generated by the regenerative power generation of the motor generator 20 is charged to the battery 22 when the vehicle 10 is braked.

The motor generator 20 is provided with a rotation sensor 200. The rotation sensor 200 detects the rotation angle θm of the output shaft of the motor generator 20 and outputs a signal corresponding to the detected rotation angle θm to the MG-ECU 63. The inverter device 21 is provided with a current sensor 210. The current sensor 210 detects each phase current value Im flowing through each phase of the motor generator 20, and outputs a signal corresponding to the detected phase current value Im to the MG-ECU 63. The MG-ECU 63 can acquire information on the rotation angle θm of the motor generator 20 based on the output signal of the rotation sensor 200, and each phase current value of the motor generator 20 based on the output signal of the current sensor 210. It is possible to acquire information on Im.

The EV-ECU 62 comprehensively controls the running of the vehicle 10 by executing a program stored in advance in its memory. Specifically, the EV-ECU 62 describes the driver's operation information such as the accelerator opening detected by the accelerator opening sensor 48, the state quantity of the vehicle 10 detected by various sensors mounted on the vehicle 10, and the ESC. -While collecting the information that can be acquired from the ECU 61 and the MG-ECU 63, the torque command value Tb * is set based on the information. The EV-ECU 62 transmits the set torque command value Tb * to the MG-ECU 63. When the MG-ECU 63 executes the energization control of the motor generator 20 based on the torque command value Tb * as described above, the torque corresponding to the torque command value Tb * is output from the output shaft of the motor generator 20. Through such torque control of the motor generator 20, the vehicle 10 can be driven according to the driver's driving request and the running state of the vehicle 10. Hereinafter, for convenience, the torque command value Tb * transmitted from the EV-ECU 62 to the MG-ECU 63 will be referred to as a “basic torque command value Tb *”.

By the way, in such a vehicle 10, when the motor generator 20 outputs a positive torque, that is, when the drive wheels 11 and 12 get over the step when the vehicle 10 is traveling forward, the drive wheels Negative torque is applied to 11 and 12 in the direction opposite to the rotation direction. This negative torque becomes a disturbance applied to the drive wheels 11 and 12. When the drive shaft 24 is twisted by the negative torque applied to the drive wheels 11 and 12, vibration may occur in the power transmission system from the motor generator 20 to the drive wheels 11 and 12. Since such vibration causes the entire vehicle 10 to vibrate, there is a risk of giving a sense of discomfort to the occupants of the vehicle 10.

Therefore, when the motor control unit 631 of the MG-ECU 63 of the present embodiment detects a twist of the drive shaft 24, it executes a process of adjusting the output torque of the motor generator 20 in a direction in which the twist is relaxed. Next, with reference to FIG. 3, a specific procedure of the process executed by the motor control unit 631 will be described. The motor control unit 631 repeatedly executes the process shown in FIG. 3 at a predetermined cycle.

As shown in FIG. 3, when the motor control unit 631 first acquires the basic torque command value Tb * transmitted from the EV-ECU 62 as the process of step S10, the motor control unit 631 first obtains the basic torque command value Tb * as the process of the subsequent step S11. Torque control of the motor generator 20 using Tb * is executed. Specifically, the motor control unit 631 determines the motor generator 20 based on the rotation angle θm of the motor generator 20 detected by the rotation sensor 200 and each phase current value Im of the motor generator 20 detected by the current sensor 210. The estimated value Tm of the output torque of is calculated by using a calculation formula or the like. Further, the motor control unit 631 uses the basic torque command value Tb * acquired in the process of step S10 as it is as the final torque command value T *. The motor control unit 631 calculates the energization control value of the motor generator 20 by executing feedback control for causing the estimated output torque Tm of the motor generator 20 to follow the final torque command value T *, and also to the calculated energization control value. The inverter device 21 is controlled based on the above. Through such feedback control, torque corresponding to the basic torque command value Tb * is output from the motor generator 20. Hereinafter, the torque control executed in step S11 will be referred to as "basic torque control".

The basic torque control executed in step S11 is not limited to the feedback control, but may be feedforward control based on the final torque command value T *.
The motor control unit 631 determines whether or not the drive shaft 24 is twisted based on the torque detected by the torque sensors 51 and 52 and the estimated output torque Tm of the motor generator 20 as the process of step S12 following step S11. Is determined. Specifically, this determination process is performed as follows.

In the vehicle 10, since the output torque of the motor generator 20 is distributed to the drive wheels 11 and 12, ideally, the sum of the torques of the drive wheels 11 and 12 is the output torque of the motor generator 20. However, since various devices such as the differential device 23 exist in the torque transmission path from the motor generator 20 to the drive wheels 11 and 12, a loss occurs in the torque transmission path. Therefore, the total torque of the drive wheels 11 and 12 is actually smaller than the output torque of the motor generator 20. Since the torque sensors 51 and 52 are arranged at both ends 241,242 of the drive shaft 24, the torques detected by the torque sensors 51 and 52 are substantially the same as the torques of the drive wheels 11 and 12, respectively. Therefore, assuming that the actual output torque of the motor generator 20 is "Tm" and the sum of the torques Tda and Tdb of the drive shaft 24 detected by the torque sensors 51 and 52 is "Td", as shown in FIG. , The torque detection value Td (= Tda + Tdb) of the drive shaft 24 is smaller than the output torque Tm of the motor generator 20.

Assuming that the drive wheels 11 and 12 ride on the step at the time t10 shown in FIG. 4, the torque detection value Td of the drive shaft 24 is increased by transmitting the negative torque applied to the drive wheels 11 and 12 to the drive shaft 24. To increase. As a result, the torque detection value Td of the drive shaft 24 reaches the output torque Tm of the motor generator 20 at time t11, and thereafter, the torque detection value Td of the drive shaft 24 shows a value larger than the output torque Tm of the motor generator 20. ..

Therefore, the motor control unit 631 of the present embodiment detects the torques Tda and Tdb of the both end portions 241,242 of the drive shaft 24 based on the output signals of the torque sensors 51 and 52, and sums them. The torque detection value Td of the drive shaft 24 is obtained by calculation. Then, the motor control unit 631 sets the output torque Tm of the motor generator 20 as the twist determination value Ttha, and when the torque detection value Td of the drive shaft 24 is less than the twist determination value Tthe, the drive shaft 24 is set. It is determined that there is no twist, and a negative determination is made in the process of step S12 shown in FIG. In this case, the motor control unit 631 temporarily ends the process shown in FIG. Therefore, when the drive shaft 24 is not twisted, the motor control unit 631 continuously performs the process shown in step S11, that is, the basic torque control using the basic torque command value Tb *.

On the other hand, when the torque detection value Td of the drive shaft 24 is equal to or higher than the twist determination value Ttha, the motor control unit 631 determines that the drive shaft 24 is twisted, and makes a positive determination in the process of step S12. conduct. In this case, the motor control unit 631 obtains the corrected final torque command value T * based on the torque detection value Td of the drive shaft 24 as the process of the subsequent step S13.

Specifically, the motor control unit 631 calculates the deviation ΔT (= | Td−Tm |) between the torque detection value Td of the drive shaft 24 and the output torque Tm of the motor generator 20. Then, the motor control unit 631 obtains the corrected final torque command value T * by correcting the basic torque command value Tb * based on the following equation f1 using the deviation ΔT.

T * = Tb * -ΔT (f1)
The motor control unit 631 executes feedback control using the corrected final torque command value T * obtained in the process of step S13 as the process of step S14 following step S13. Specifically, the motor control unit 631 calculates the energization control value of the motor generator 20 by executing feedback control that causes the estimated output torque Tm of the motor generator 20 to follow the corrected final torque command value T *. , The inverter device 21 is controlled based on the calculated energization control value. Through such feedback control, torque corresponding to the torque command value (Tb * −ΔT) is output from the motor generator 20. Hereinafter, the torque control executed in step S14 will be referred to as "torque elimination torque control".

The motor control unit 631 determines whether or not the twist of the drive shaft 24 has been eliminated as the process of step S15 following step S14. Specifically, when the torque detection value Td of the drive shaft 24 is equal to or higher than the twist elimination determination value Tthb, the motor control unit 631 determines that the twist of the drive shaft 24 has not been eliminated, and in step S15. Make a negative judgment in the process. The twist elimination determination value Tthb can be set, for example, to a value smaller than the output torque Tm of the motor generator 20 by a predetermined value. When the motor control unit 631 makes a negative determination in the process of step S15, the motor control unit 631 returns to the process of step S13. Therefore, the motor control unit 631 continuously performs the twist elimination torque control in step S14.

On the other hand, when the torque detection value Td of the drive shaft 24 is less than the twist elimination determination value Tthb, the motor control unit 631 determines that the twist of the drive shaft 24 has been eliminated, and is positive in the process of step S15. Make a judgment. In this case, the motor control unit 631 ends a series of processes shown in FIG. Therefore, the motor control unit 631 re-executes the process shown in FIG. 3 after the elapse of a predetermined cycle, so that the basic torque control in step S11 is restarted.

Next, an operation example of the vehicle 10 of the present embodiment will be described with reference to FIG.
When the drive wheels 11 and 12 climb on a step at time t10 as shown in FIG. 4, the torque detection value Td of the drive shaft 24 becomes the output torque Tm of the motor generator 20 at time t11 as shown by the alternate long and short dash line. When it reaches, the motor control unit 631 determines that the drive shaft 24 is twisted. Therefore, after the time t11, the final torque command value T * is set to the corrected torque command value (Tb * −ΔT), so that the final torque command value T * gradually decreases as shown by the alternate long and short dash line. Since the actual output torque Tm of the motor generator 20 changes so as to follow the change of the final torque command value T *, the actual output torque Tm of the motor generator 20 also gradually decreases as shown by the solid line.

As the actual output torque Tm of the motor generator 20 decreases, the torque that causes the drive shaft 24 to twist is generated from the drive shaft 24 before the drive shaft 24 is completely twisted by the negative torque transmitted from the drive wheels 11 and 12. Will be removed. Therefore, since it is possible to prevent the drive shaft 24 from being completely twisted, it is possible to suppress the vibration of the vehicle 10 due to the twisting of the drive shaft 24.

After that, when the drive wheels 11 and 12 get over the step at time t12, the negative torque applied to the drive wheels 11 and 12 is removed, so that the torque detection value of the drive shaft 24 is shown by the alternate long and short dash line. Td decreases rapidly toward the original value. As a result, the deviation ΔT decreases, so that the final torque command value T * set in the corrected torque command value (Tb * −ΔT) increases after the time t12. After that, when the torque detection value Td of the drive shaft 24 reaches the twist elimination determination value Tthb at time t13, the motor control unit 631 determines that the twist of the drive shaft 24 has been eliminated. Therefore, after the final torque command value T * changes stepwise toward the basic torque command value Tb * at time t13, the final torque command value T * is maintained at the basic torque command value Tb *. The actual output torque Tm of the motor generator 20 changes as shown by the solid line so as to follow the change of the final torque command value T *.

According to the control device 60 of the vehicle 10 of the present embodiment described above, the actions and effects shown in the following (1) to (5) can be obtained.
(1) The motor control unit 631 obtains the torque detection value Td of the drive shaft 24 from the torque detection values Tda and Tdb of the torque sensors 51 and 52. Further, in the process of step S13 shown in FIG. 3, the motor control unit 631 corrects the basic torque command value Tb * based on the torque detection value Td of the drive shaft 24 as shown in the above equation f1. Calculate the final torque command value T *. Then, in the process of step S14, the control device 60 executes the untwisting torque control that causes the estimated output torque Tm of the motor generator 20 to follow the final torque command value T *. That is, the motor control unit 631 controls the motor generator 20 based on the torque detection values Tda and Tdb and the output torque Tm of the motor generator 20. According to this configuration, the motor generator 20 can be controlled so that the torque that causes the twist is removed from the drive shaft 24, so that the drive shaft 24 can be prevented from being completely twisted. As a result, vibration of the vehicle 10 due to the twist of the drive shaft 24 can be suppressed.

(2) Assuming that the output signals of the torque sensors 51 and 52 are input to the EV-ECU 62, the motor control unit 631 acquires the information of the torque detection values Tda and Tdb of the torque sensors 51 and 52 from the EV-ECU 62. It will be. In the case of this configuration, there is a time delay from the time when the torque is detected by the torque sensors 51 and 52 until the motor control unit 631 acquires the torque information. In this regard, in the control device 60 of the present embodiment, the output signals of the torque sensors 51 and 52 are directly input to the motor control unit 631. According to this configuration, the motor control unit 631 acquires the torque detection values Tda and Tdb of the torque sensors 51 and 52 earlier than the configuration in which the output signals of the torque sensors 51 and 52 are input to the EV-ECU 62. Therefore, the responsiveness of the control can be improved.

(3) The torque calculation unit 630 and the motor control unit 631 are mounted on the MG-ECU 63 including one microcomputer. According to this configuration, the configuration can be simplified as compared with the case where the torque calculation unit 630 and the motor control unit 631 are mounted on two different microcomputers.

(4) The motor control unit 631 sets the twist determination value Tthe based on the output torque Tm of the motor generator 20, and also sets the drive shaft 24 based on the comparison between the torque detection value Td of the drive shaft 24 and the twist determination value Tthe. Detects twisting. According to this configuration, the twist of the drive shaft 24 can be detected more accurately.

(5) When the motor control unit 631 detects a twist of the drive shaft 24, the motor control unit 631 corrects the final torque command value T * based on the torque detection value Td of the drive shaft 24. According to this configuration, the output torque Tm of the motor generator 20 can be controlled so that the twist is removed from the drive shaft 24, so that the twist of the drive shaft 24 can be avoided more accurately. As a result, the vibration of the vehicle 10 can be further suppressed.

(First modification)
Next, a first modification of the control device 60 of the first embodiment will be described.
As shown in FIG. 5, the vehicle 10 of the present embodiment further includes a motor generator 70 for driving the right rear wheel 13 and the left rear wheel 14, a differential device 73, and a drive shaft 74. The motor generator 70 is driven based on the three-phase AC power supplied from the inverter device 21. The driving force of the motor generator 70 is transmitted to the right rear wheel 13 and the left rear wheel 14 via the differential device 73 and the drive shaft 74, so that the right rear wheel 13 and the left rear wheel 14 rotate. Therefore, in the vehicle 10 of this modification, the right rear wheel 13 and the left rear wheel 14 are also driving wheels.

The inverter device 21 is separately provided with a circuit for supplying three-phase AC power to the motor generator 20 and a circuit for supplying three-phase AC power to the motor generator 70. Therefore, the motor generator 20 and the motor generator 70 operate independently of each other. The inverter device corresponding to the motor generator 20 and the inverter device corresponding to the motor generator 70 may be provided separately.

Further, the vehicle 10 is further provided with a torque sensor 53 for detecting the torque applied to one end 741 of the drive shaft 74 and a torque sensor 54 for detecting the torque applied to the other end 742 of the drive shaft 74. .. The torque sensors 53 and 54 output a signal corresponding to the detected torque to the MG-ECU 63. Therefore, the torque calculation unit 630 of the MG-ECU 63 detects the torque applied to one end 741 of the drive shaft 74 and the torque applied to the other end 742 of the drive shaft 74 based on the output signals of the torque sensors 53 and 54. be able to.

Further, the motor control unit 631 sets the basic torque command values Tb1 * and Tb2 * of the motor generator 20 and the motor generator 70, respectively, based on the basic torque command value Tb * in the process of step S11 shown in FIG. .. The motor control unit 631 sets the basic torque command value Tb1 * to the first final torque command value T1 *, and then performs feedback control for causing the estimated output torque Tm1 of the motor generator 20 to follow the first final torque command value T1 *. By executing this, the output torque of the motor generator 20 is controlled. Similarly, the motor control unit 631 sets the basic torque command value Tb2 * to the second final torque command value T2 *, and then causes the estimated output torque Tm2 of the motor generator 70 to follow the second final torque command value T2 *. The output torque of the motor generator 70 is controlled by executing the feedback control.

Further, when the motor control unit 631 makes a positive determination in the process of step S12 shown in FIG. 3, the final process after correction is performed as the process of step S13 based on the torque detection value Td of the drive shaft 24. Obtain the torque command values T1 * and T2 *. Specifically, the motor control unit 631 obtains the final torque command values T1 * and T2 * by using the following equations f2 and f3.

T1 * = Tb1 * -ΔT (f2)
T2 * = Tb2 * + ΔT (f3)
The motor control unit 631 controls the output torques of the motor generators 20 and 70 by using these final torque command values T1 * and T2 *.

According to this configuration, even when the output torque of one motor generator 20 is reduced in order to eliminate the twist of the drive shaft 24, the reduced torque is output from the other motor generator 70. become. Therefore, since the traveling torque of the vehicle 10 as a whole does not decrease, it is possible to suppress changes in the acceleration of the vehicle 10. Therefore, it is possible to reduce the discomfort of the occupants of the vehicle 10 while suppressing the vibration of the vehicle 10 caused by the twist of the drive shaft 24.

(Second modification)
Next, a second modification of the control device 60 of the first embodiment will be described.
As shown in FIG. 6, the motor control unit 631 of the present embodiment has the wheel speeds ωw11 of the drive wheels 11 and 12 detected by the wheel speed sensors 41 and 42 as the process of the step S16 following the step S14. It is determined whether or not both ωw12 are equal to or higher than the predetermined speed. The predetermined speed is set to a value at which it can be determined whether, for example, the wheel speeds ωw11 and ωw12 are zero or indicate a value near zero.

When the wheel speeds ωw11 and ωw12 are both equal to or higher than the predetermined speed, the motor control unit 631 makes a positive judgment in the process of step S16. In this case, the motor control unit 631 determines that the drive wheels 11 and 12 can get over the step, and executes the processes after step S15. As a result, in a situation where the drive wheels 11 and 12 can get over the step, the twist elimination torque control shown in step S14 is continuously executed, so that the vibration of the vehicle 10 can be suppressed.

On the other hand, when at least one of the wheel speeds ωw11 and ωw12 is less than the predetermined speed, the motor control unit 631 makes a negative judgment in the process of step S16. In this case, the motor control unit 631 determines that the drive wheels 11 and 12 cannot get over the step, and temporarily ends the process shown in FIG. In this case, even when the twist elimination torque control shown in step S14 is executed, the basic torque shown in step S11 is executed by executing the process shown in FIG. 6 again after the elapse of a predetermined cycle. Control is executed. That is, when the drive wheels 11 and 12 cannot get over the step, the control of the motor generator 20 shifts from the untwisting torque control to the basic torque control. As a result, the final torque command value T * returns from the calculated value of the above equation f1 to the basic torque command value Tb *, so that the torque transmitted to the drive wheels 11 and 12 increases. Therefore, the drive wheels 11 and 12 can easily get over the step.

The motor control unit 631 finally uses a filtering process so that the output torque Tm of the motor generator 20 does not change stepwise when shifting the control of the motor generator 20 from the untwisting torque control to the basic torque control. The torque command value T * may be changed smoothly.

<Second Embodiment>
Next, the control device 60 of the vehicle 10 of the second embodiment will be described. Hereinafter, the differences of the control device 60 of the first embodiment will be mainly described.
When the motor control unit 631 of the first embodiment detects the twist of the drive shaft 24, it sets the final torque command value T * to the corrected torque command value (Tb * −ΔT), and then sets the final torque command value (Tb * −ΔT). The output torque Tm of the motor generator 20 was controlled based on the value T *. In the case of such a configuration, if the frequency component of the final torque command value T * includes the resonance frequency of the drive shaft 24, the drive shaft 24 may resonate and the vibration of the vehicle 10 may be amplified. be.

Therefore, the control device 60 of the present embodiment suppresses the resonance of the drive shaft 24 by removing the component of the resonance frequency of the drive shaft 24 from the frequency component of the final torque command value T *.
Specifically, as shown in FIG. 7, the motor control unit 631 further includes a frequency component extraction unit 631a and a filter unit 631b.

The output signals of the torque sensors 51 and 52 are input to the frequency component extraction unit 631a. The frequency component extraction unit 631a extracts the frequency components of the output signals of the torque sensors 51 and 52 when a positive determination is made in step S12 shown in FIG. 3, that is, when a twist of the drive shaft 24 is detected. At the same time as extracting, the information of the extracted frequency component is transmitted to the filter unit 631b. As a method for extracting the frequency components of the output signals of the torque sensors 51 and 52, for example, a fast Fourier transform (FFT) can be used. The torque detected by the torque sensors 51 and 52 is the torque applied to the drive shaft 24. Therefore, if the drive shaft 24 vibrates due to twisting, the output signals of the torque sensors 51 and 52 also vibrate. That is, there is a correlation between the vibration frequency of the drive shaft 24 and the vibration frequency of the torque sensors 51 and 52. Therefore, the frequency component of the vibration of the drive shaft 24 can be extracted by extracting the frequency component of the output signals of the torque sensors 51 and 52 by the frequency component extraction unit 631a.

The frequency component information transmitted from the frequency component extraction unit 631a is input to the filter unit 631b, and the final torque command value T * is input to the filter unit 631b. The filter unit 631b performs a filtering process based on the notch filter on the final torque command value T * based on the frequency component information transmitted from the frequency component extraction unit 631a.

Specifically, the filter unit 631b determines that the frequency component whose power spectrum is equal to or higher than a predetermined value among the frequency components transmitted from the frequency component extraction unit 631a is the resonance frequency of the drive shaft 24. After specifying the resonance frequency of the drive shaft 24 in this way, the filter unit 631b performs a filtering process based on the notch filter for attenuating the specified resonance frequency on the final torque command value T *.

According to the control device 60 of the vehicle 10 of the present embodiment described above, the actions and effects shown in (6) below can be further obtained.
(6) Since the resonance frequency component of the drive shaft 24 is removed from the frequency component of the final torque command value T *, the torque corresponding to the final torque command value T * is transmitted from the motor generator 20 to the drive shaft 24. Even so, the resonance of the drive shaft 24 can be suppressed. Therefore, it is possible to suppress the vibration of the vehicle 10 due to the resonance of the drive shaft 24.

<Other embodiments>
In addition, each embodiment can also be implemented in the following embodiments.
As a device for transmitting torque to the drive wheels 11 and 12, for example, as shown in FIG. 8, an integrated device 80 in which a motor generator 20, an inverter device 21, a speed reducer 25, and torque sensors 51 and 52 are modularized. May be used.

The twist determination value Tthe used in the process shown in step S12 of FIG. 3 and the twist elimination determination value Tthb obtained in the process of step S15 may be set to the same value.
-The torque sensors 51 and 52 may be provided in the torque transmission path from the drive shaft 24 to the drive wheels 11 and 12. As such a torque transmission path, for example, there is a hub provided between the drive shaft 24 and the drive wheels 11 and 12.

-The vehicle 10 shown in FIG. 1 may be provided with only one of the torque sensors 51 and 52. Further, the vehicle 10 shown in FIG. 5 may be provided with only one of the torque sensors 51 and 52 and may be provided with only one of the torque sensors 53 and 54.

Each ECU 61-63 and its control method described in the present disclosure is provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, it may be realized by a plurality of dedicated computers. Each ECU 61-63 described in the present disclosure and a control method thereof may be realized by a dedicated computer provided by configuring a processor including one or a plurality of dedicated hardware logic circuits. Each ECU 61-63 and its control method described in the present disclosure comprises a combination of a processor and memory programmed to perform one or more functions and a processor including one or more hardware logic circuits. It may be realized by one or more dedicated computers. The computer program may be stored on a computer-readable non-transitional tangible recording medium as an instruction executed by the computer. The dedicated hardware logic circuit and the hardware logic circuit may be realized by a digital circuit including a plurality of logic circuits or an analog circuit.

・ This disclosure is not limited to the above specific examples. Specific examples described above with appropriate design changes by those skilled in the art are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the above-mentioned specific examples, and their arrangement, conditions, shape, and the like are not limited to those illustrated, and can be changed as appropriate. The combinations of the elements included in each of the above-mentioned specific examples can be appropriately changed as long as there is no technical contradiction.

Claims (8)

1. A control device that controls an electric motor (20, 70) that transmits torque to the drive wheels (11, 12, 13, 14) of the vehicle (10).
   A torque sensor (51, 52, 53, 54) that detects the torque applied to the drive shaft (24, 74) that transmits the torque of the electric motor to the drive wheels, and
   A vehicle control device including a motor control unit (631) that controls the electric motor based on the torque detected by the torque sensor and the output torque of the electric motor.
2. The vehicle control device according to claim 1, wherein the torque sensor is provided on the drive shaft or a torque transmission path from the drive shaft to the drive wheels.
3. The vehicle control device according to claim 1 or 2, wherein the output signal of the torque sensor is directly input to the motor control unit.
4. Further, a torque calculation unit (630) for calculating the torque applied to the drive shaft based on the output signal of the torque sensor is provided.
   The vehicle control device according to claim 3, wherein the torque calculation unit and the motor control unit are mounted on one microcomputer (63).
5. The vehicle control device according to any one of claims 1 to 4, wherein the electric motor and the torque sensor are modularized as one device (80).
6. The vehicle control device according to any one of claims 1 to 5, wherein the motor control unit detects a twist of the drive shaft based on a torque detected by the torque sensor and an output torque of the electric motor. ..
7. The motor control unit
   It executes feedback control that causes the output torque of the electric motor to follow the torque command value.
   The vehicle control device according to claim 6, wherein when a twist of the drive shaft is detected, the torque command value is corrected based on the torque detected by the torque sensor.
8. The motor control unit
   A frequency component extraction unit (631a) that extracts a frequency component of the output signal of the torque sensor when a twist of the drive shaft is detected, and a frequency component extraction unit (631a).
   The vehicle control device according to claim 7, further comprising a filter unit (631b) that performs a filtering process for attenuating the frequency component extracted by the frequency component extraction unit with respect to the torque command value.

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