JP7310114B2 - motor controller - Google Patents

Description

The present invention relates to a motor control device for a vehicle equipped with a left motor and a right motor.

2. Description of the Related Art Conventionally, a technique is known in which two motors mounted on a vehicle individually control the driving force of the left wheel and the driving force of the right wheel. In other words, this technology improves turning performance and vehicle stability by controlling the driving force of the left and right wheels individually. The left and right motors are connected to the left and right wheels, respectively, and the driving force transmission paths of the left and right wheels can be made independent of each other (see Patent Document 1). A vehicle has also been developed in which two motors are connected to the left and right wheels, respectively, and the driving force transmission paths of the left and right wheels are connected by a differential device. With such a structure, passive torque distribution and active torque distribution can be selectively used according to the running state.

Japanese Patent Application Laid-Open No. 2007-161190

In a vehicle in which the left and right wheels can operate independently, control for suppressing torque vibration and torsional vibration of the drive shaft is individually controlled for the left wheel side and the right wheel side. On the other hand, the torque vibration of the drive wheels can be caused not only by the structure of each of the left and right wheels, but also by fluctuations in the torque difference between the left and right wheels. In addition, the torque difference between the left and right wheels changes not only when the vehicle turns, but also depending on the road surface and tire conditions. Conventional systems do not consider vibrations caused by such torque differences, and there is room for improvement in terms of improving the quietness and ride comfort in the passenger compartment.

In addition, the motors mounted on recent vehicles have high responsiveness, and it is possible to change the torque difference with a fluctuation period close to the natural frequency of the drive train of the left and right wheels. Therefore, in a system that distributes torque between the left and right wheels using the difference in torque between the motors, vibrations near the natural frequency of the drivetrain are more noticeable than in existing torque distribution systems that use hydraulic pressure. There is

One of the objectives of the present invention was invented in view of the above problems, and a motor control device that suppresses vibrations caused by the torque difference between the left and right wheels and improves quietness and ride comfort. is to provide In addition to this purpose, it is also possible to achieve actions and effects derived from each configuration shown in the "Mode for Carrying out the Invention" described later and which cannot be obtained with conventional techniques. can be positioned as a goal.

The motor control device disclosed herein is a motor control device for a vehicle equipped with a left motor that transmits driving force to left wheels via a left shaft and a right motor that transmits driving force to right wheels via a right shaft. be.
(1) The disclosed motor control device includes a drive train torsion model that models torsional characteristics in power transmission paths between the left motor and the left shaft and between the right motor and the right shaft. A drive train torsion model that calculates the left shaft rotation speed and the right shaft rotation speed affected by the torsional vibration of the power transmission path using the first rotation speed of the left motor and the second rotation speed of the right motor. A calculator is provided. A correction value calculation unit that calculates a feedback correction amount for reducing torque vibration of the left shaft and the right shaft due to torsional vibration of the power transmission path based on the difference between the left shaft rotation speed and the right shaft rotation speed. Prepare. Further, a control unit is provided for controlling shaft torques of the left motor and the right motor based on the feedback correction amount.

(2) It is preferable that the correction value calculation unit calculates the feedback correction amount so that a differential value of a difference between the left shaft rotation speed and the right shaft rotation speed becomes small.
(3) The correction value calculation unit includes a differentiation calculation unit that calculates a differential value of the difference between the left shaft rotation speed and the right shaft rotation speed, and a predetermined frequency based on the differential value calculated by the differentiation calculation unit. a frequency filter that extracts a component; a proportional term calculator that calculates a proportional term that is a correction amount proportional to the frequency component extracted by the frequency filter; an integral term calculator that calculates an integral term that is a corresponding correction amount; and a differential term calculator that calculates a differential term that is a correction amount corresponding to a differential value of the frequency component extracted by the frequency filter. is preferred. Moreover, it is preferable that the feedback correction amount is a sum of the proportional term, the integral term, and the differential term.
( 4 ) It is preferable that the control section reflects the feedback correction amount on the required torque difference between the left shaft and the right shaft.

(5) A vehicle body attitude control device for calculating, as the required torque difference, a yaw motion required torque difference, which is a difference in torque between left and right wheels required to generate the yaw moment required for the vehicle, wherein the control unit However, the post-correction torque difference is generated based on the post-correction torque difference obtained by subtracting the feedback correction amount from the yaw motion request torque difference calculated by the vehicle body posture control device and the driver request torque. It is preferable to calculate shaft torques of the left motor and the right motor.
( 6 ) It is preferable to include each shaft driving torque calculating section, torque vibration estimating section, and damping torque calculating section. The drive torque calculation unit for each shaft calculates a required left shaft torque, which is the torque required for the left shaft, and a required right shaft torque, which is the torque required for the right shaft, based on the running state of the vehicle. . The torque oscillation estimating unit is configured to generate torques for each of the left shaft and the right shaft based on a torque transmission model that models resonance characteristics of the left shaft and the right shaft, the required left shaft torque, and the required right shaft torque. Estimate torque oscillations. The damping torque calculation unit calculates a damping torque for reducing torque vibrations of the left shaft and the right shaft derived from the torque vibrations. Further, the control unit controls the shaft torques of the left motor and the right motor based on the driver requested torque, the requested left shaft torque, the requested right shaft torque, the damping torque, and the feedback correction amount. is preferred.

( 7 ) The control unit adjusts the shaft torque difference between a value obtained by subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque and a value obtained by adding the damping torque to the other. Preferably, the shaft torques of the left motor and the right motor are controlled based on the feedback correction amount.

Vibration resulting from the torque difference between the left and right wheels can be suppressed, and quietness and ride comfort can be improved.

1 is a block diagram showing the configuration of a vehicle to which a motor control device is applied; FIG. It is a block diagram which shows the hardware constitutions of a motor control apparatus. It is a block diagram which shows the function of a feedforward control part. 4 is a block diagram showing functions of a feedback control unit; FIG. It is a block diagram which shows the function of a feedback feedforward control part. It is a block diagram which shows the modification of a feedback feedforward control part. 7 is a graph (comparative example) showing changes over time in torque oscillation. 7 is a graph (example) showing changes over time in torque oscillation. FIG. 11 is a block diagram showing a modification of the configuration of the vehicle; FIG.

[1. Hardware configuration]
A configuration of a vehicle 10 to which a motor control device as an embodiment is applied will be described below with reference to the drawings. As shown in FIG. 1, this vehicle 10 is equipped with a differential gear 5 (differential gear) having an AYC (active yaw control) function. A differential gear 5 is interposed between a left shaft 3 connected to a left wheel 1 (left driving wheel) and a right shaft 4 connected to a right wheel 2 (right driving wheel).

The AYC function is a function that adjusts the magnitude of the yaw moment by mainly controlling the sharing ratio of driving force (driving torque) between the left and right driving wheels, thereby stabilizing the attitude of the vehicle 10 in the yaw direction. . The differential gear 5 of the present embodiment has not only the AYC function, but also the function of transmitting the driving force to the left and right wheels to drive the vehicle 10, and passively reducing the rotational speed difference between the left and right wheels that occurs when the vehicle 10 turns. It also has the ability to absorb.

Two motors 6 and 7 are built in the differential gear 5 . One is a left motor 6 that transmits driving force to the left wheel 1 via the left shaft 3 and the other is a right motor 7 that transmits driving force to the right wheel 2 via the right shaft 4 . All of these are motor generators (MG) that combine the function of an electric motor and the function of a generator. The left motor 6 is mainly responsible for driving the left wheel 1, and the right motor 7 is mainly responsible for driving the right wheel 2.

Resolvers and encoders as sensors 16 and 17 for detecting the rotational angle and rotational speed of the rotor with respect to the stator are built into each motor 6 and 7 . The left rotation speed sensor 16 detects a first rotation speed (rotation speed per unit time) of the left motor 6, and the right rotation speed sensor 17 detects a second rotation speed of the right motor 7. do. Signals detected by these sensors 16 and 17 are transmitted to the motor controller 15 .

The operating state of each motor 6 , 7 is controlled by left inverter 8 and right inverter 9 . Each of the inverters 8 and 9 is a converter (DC-AC inverter) that converts DC power fed from the battery 11 into AC power and supplies the same to the motors 6 and 7 . Each inverter 8, 9 incorporates a three-phase bridge circuit including a plurality of switching elements. AC power is generated by intermittently switching the connection state of each switching element. Also, by controlling the switching frequency and output voltage, the output (shaft torque and rotation speed) of each motor 6 and 7 is adjusted. The operating state of each motor 6, 7 and each inverter 8, 9 is controlled by a motor control unit 15 (M-ECU; Motor-Electronic Control Unit) as an embodiment.

The motor control device 15 is an electronic control device (computer) that performs control for suppressing vibration caused by the torque difference between the left and right wheels 1 and 2 . As shown in FIG. 2, the motor control device 15 incorporates a processor 61 (central processing unit), a memory 62 (main memory), a storage device 63 (storage), an interface device 64, etc., which connect to an internal bus 65. connected through The processor 61 is a central processing unit containing a control unit (control circuit), an arithmetic unit (arithmetic circuit), a cache memory (register group), and the like.

The memory 62 is a storage device for storing programs and data during operation, and includes, for example, ROM (Read Only Memory) and RAM (Random Access Memory). The storage device 63 is a memory device that stores data and firmware that are held longer than the memory 62, and includes non-volatile memory such as flash memory and EEPROM. The interface device 64 controls input and output (I/O) between the motor control device 15 and the outside.

The motor control device 15 is connected to the accelerator opening sensor 12 , the vehicle speed sensor 13 , and the vehicle body posture control device 14 (vehicle body posture ECU) via the interface device 64 . The accelerator opening sensor 12 is a sensor that outputs a signal corresponding to the accelerator opening (the amount of depression of the accelerator pedal), and the vehicle speed sensor 13 is a sensor that outputs a signal corresponding to the traveling speed of the vehicle 10 (vehicle speed). The driver-requested torque of the vehicle 10 is set based on the accelerator opening and the running speed, and is acquired by the motor control device 15 . The control configuration may be such that the motor control device 15 calculates the driver requested torque, or the control configuration may be such that the motor control device 15 receives the driver requested torque calculated by another device.

The vehicle body posture control device 14 is an electronic control device for adjusting the target torque of each wheel including the left and right wheels 1 and 2 according to vehicle speed, longitudinal acceleration, lateral acceleration, angular velocity, steering angle, and the like. The motor control device 15 acquires the yaw motion required torque difference calculated by the vehicle body posture control device 14 . The yaw motion required torque difference means the torque difference between the left and right wheels 1 and 2 required to generate the yaw moment required for the vehicle 10 . Note that the control configuration may be such that the motor control device 15 calculates the yaw motion required torque difference.

As shown in FIG. 2, motor controller 15 has at least two functions. The first function is to calculate the required left motor shaft torque and the required right motor shaft torque based on the difference between the driver required torque and the yaw motion required torque. The second function is to control the operating state of each inverter 8, 9 so that the torque output from the left motor 6 matches the required left motor shaft torque, and the torque output from the right motor 7 is adjusted to the required right motor shaft torque. It is a function to match the motor shaft torque. As for the first function, any one of the following four methods can be used to calculate the shaft torque of each motor 6,7.

The first method is by feedforward control. A torque transmission model that models the resonance characteristics of the left shaft 3 and the right shaft 4 is used in the feedforward control. The motor control device 15 estimates the torque vibration of each shaft 3 and 4 using a torque transmission model, and calculates damping torque for reducing the vibration of the difference between them (that is, the shaft torque difference). Further, the shaft torques of the left motor 6 and the right motor 7 (required left motor shaft torque, requested right motor shaft torque) are the required left shaft torque required for the left shaft 3 and the required right shaft torque required for the right shaft 4. , damping torque.

Note that the requested left shaft torque and the requested right shaft torque are calculated based on the running state of the vehicle 10 (for example, the requested torque difference, the driver requested torque, etc.). In this way, by predicting the vibration state of the left shaft 3 and right shaft 4 using a torque transmission model prepared in advance, it is possible to suppress the vibration derived from the torque difference before it occurs, resulting in a good response. It becomes easier to obtain sexuality. Hereinafter, the entity (circuit or program) that performs feedforward control will be referred to as feedforward control section 20 .

A second approach is through feedback control. In feedback control, a feedback correction amount is calculated based on the first rotation speed of the left motor 6 and the second rotation speed of the right motor 7 . Further, the shaft torques of the left motor 6 and the right motor 7 (requested left motor shaft torque, requested right motor shaft torque) depend on the running state of the vehicle 10 (for example, the required torque difference, the driver's required torque, etc.) and the feedback correction amount. controlled based on By feeding back the rotation speed of each motor 6 and 7 to the magnitude of the shaft torque in this manner, vibrations caused by torque differences can be corrected with high accuracy, and control stability is improved. Hereinafter, the entity (circuit or program) that implements the feedforward control will be referred to as the feedback control section 30 .

The third method is based on feedback control and adds feedforward control to it. In this case, the difference between the shaft torques of the shafts 3 and 4 calculated by the feedforward control (required shaft torque difference) is calculated, and the feedback correction amount is reflected in this. By using both feedback control and feedforward control in this way, the effect of suppressing vibrations caused by torque differences is further improved. Hereinafter, the entity (circuit or program) that performs feedforward control based on feedback control will be referred to as a feedback/feedforward control unit 40 .

The fourth technique is based on feedforward control and adds feedback control to it. In this case, when estimating the torque oscillation of each shaft 3 and 4 by feedforward control, the feedback correction amount is reflected in the value input to the torque transmission model. Even when such feedback control and feedforward control are used in combination, it is possible to improve the effect of suppressing vibration caused by the torque difference. Hereinafter, the entity (circuit or program) that performs feedback control based on feedforward control will be referred to as a feedback/feedforward control unit 60 .

[2. Software configuration]
[A. feedforward control]
FIG. 3 is a block diagram for explaining the processing contents of one of the programs (feedforward control section 20) executed by the motor control device 15. As shown in FIG. These processing contents are recorded as an application program in the storage device 63 of the motor control device 15 or a recording medium readable by the motor control device 15, expanded on the memory 62, and executed. Functionally classifying the processing contents to be executed here, the feedforward control unit 20 includes a drive torque calculation unit 21 for each shaft, a torque vibration estimation unit 22, a damping torque calculation unit 23, and a motor shaft torque control unit 24. be provided.

Each shaft driving torque calculation unit 21 calculates a required left shaft torque required for the left shaft 3 and a required right shaft torque required for the right shaft 4 based on the running state of the vehicle 10 . The running state of the vehicle 10 referred to here includes at least the required torque difference and the driver's required torque. Note that when the road surface frictional resistance of the left and right wheels 1 and 2 is the same and the vehicle 10 is traveling straight, the required left axle torque and the required right axle torque are calculated as substantially the same value. On the other hand, when the vehicle 10 is turning or when the road surface frictional resistance of the left and right wheels 1 and 2 is uneven, the required left axle torque and the required right axle torque can be calculated as different values. The calculation result here is transmitted to the torque oscillation estimating section 22 .

The torque vibration estimating section 22 estimates torque vibrations on each of the left shaft 3 and the right shaft. A torque transmission model that models the resonance characteristics of the left shaft 3 and the right shaft 4 is used for estimating the torque vibration. The torque transmission model includes a left torque estimated value that simulates the actual torque oscillation with respect to the required left shaft torque of the left shaft 3 and a right torque estimated value that simulates the actual torque oscillation with respect to the required right shaft torque of the right shaft 4. to output Thus, the torque oscillation estimator 22 has a function of estimating torque oscillations in each of the left shaft 3 and the right shaft 4 based on the torque transmission model, the required left shaft torque, and the required right shaft torque. The two torque estimation values estimated here are transmitted to the damping torque calculation section 23 .

The vibration damping torque calculator 23 calculates a vibration damping torque for reducing the vibration of the shaft torque difference between the left shaft 3 and the right shaft 4 . Here, the damping torque is calculated as a correction value for making the difference between the torque estimated values (for example, the left torque estimated value minus the right torque estimated value) an originally intended value. For example, when the left torque estimated value and the right torque estimated value are the same while the vehicle 10 is running straight ahead, the value of the damping torque becomes zero. On the other hand, if the estimated left torque value is greater than the estimated right torque value while the vehicle 10 is traveling straight ahead, the damping torque value is positive. Conversely, if the estimated left torque value is smaller than the estimated right torque value while the vehicle 10 is traveling straight ahead, the damping torque value will be negative. Further, while the vehicle 10 is turning, the damping torque having a magnitude corresponding to the turning state is calculated. The damping torque value calculated here is transmitted to the motor shaft torque control section 24 .

The motor shaft torque control unit 24 (control unit) controls shaft torques of the left motor 6 and the right motor 7 based on the required left shaft torque, the required right shaft torque, and the damping torque. Here, the requested left motor shaft torque and the requested right motor shaft torque are calculated based on the value obtained by subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque, and the value obtained by adding the damping torque to the other. torque is calculated.

In the present embodiment, the sum of the requested left shaft torque and the damping torque is the final shaft torque requested for the left shaft 3, and the damping torque is subtracted from the requested right shaft torque. is the shaft torque finally required for the right shaft 4 . The required left motor shaft torque is the shaft torque of the left motor 6 required to generate the former in the left shaft 3, and the required right motor shaft torque is the right motor 7 required to generate the latter in the right shaft 4. is the axial torque of The motor shaft torque control unit 24 outputs a control signal to the left inverter 8 so that the left motor 6 generates the required left motor shaft torque, and the right inverter 9 so that the right motor 7 generates the required right motor shaft torque. output a control signal to

[B. feedback control]
FIG. 4 is a block diagram for explaining the processing contents of one of the programs (feedback control section 30) executed by the motor control device 15. As shown in FIG. These processing contents are executed as an application program in the same manner as the feedforward control unit 20 described above. If functionally classifying the processing contents executed here, the drive train torsion model calculation unit 31, the differential operation unit 32, the frequency filter 33, the proportional term calculation unit 34, the integral term calculation unit 35, the differential term calculation unit 36, the allocation A control unit 37 is provided.

The drive train torsion model calculation unit 31 calculates the rotation speed of each of the left shaft 3 and the right shaft 4 (left shaft rotation speed, right shaft rotation speed) based on the rotation speeds of the motors 6 and 7 . Here, a drive train torsional model is used that models the reduction ratio and torsional characteristics in the power transmission path between the motors 6, 7 and the shafts 3, 4. Difference information between the left shaft rotation speed and the right shaft rotation speed calculated here is transmitted to the differential operation unit 32 . In this embodiment, the rotation speed difference obtained by subtracting the right shaft rotation speed from the left shaft rotation speed is transmitted to the differential operation unit 32 .

The differential calculation unit 32 calculates a differential value, which is a time-varying gradient of the rotational speed difference. Here, the amount of change in the rotational speed difference per predetermined unit time is extracted. By applying the differential operation, it becomes possible to calculate the feedback correction amount according to the degree of change, regardless of the magnitude of the rotation speed difference between the shafts 3 and 4 . Information on the amount of change extracted here is transmitted to each of the three types of calculators 34 to 36 after extracting necessary frequency components by the frequency filter 33 .

The proportional term calculator 34 calculates a correction amount (proportional term) proportional to the output of the frequency filter 33 . Similarly, the integral term calculator 35 calculates a correction amount (integral term) corresponding to the integral value of the output of the frequency filter 33, and the differential term calculator 36 calculates the correction value corresponding to the differential value of the output of the frequency filter 33. Calculate the quantity (differential term). The sum of these correction amounts is the final feedback correction amount. Note that each element denoted by reference numerals 31 to 36 in FIG. 4 functions as a correction value calculator that calculates the feedback correction amount based on the first rotation speed and the second rotation speed.

The feedback correction amount is such that the differential value of the difference between the first rotation speed of the left motor 6 and the second rotation speed of the right motor 7 is reduced (the differential value of the difference is brought closer to 0, and the change in the difference over time is suppressed). It is used to correct the yaw motion required torque difference calculated by the vehicle body attitude control device 14 . Hereinafter, the difference obtained by subtracting the feedback correction amount from the required torque difference for yaw motion will be referred to as the post-correction torque difference.

The distribution control section 37 (control section) calculates the shaft torques of the left motor 6 and the right motor 7 based on at least the feedback correction amount. Here, the requested left motor shaft torque and the requested right motor shaft torque are calculated based on the post-correction torque difference and the driver requested torque. That is, the required left shaft torque and the required right shaft torque are calculated so as to generate the post-correction torque difference, and the required left motor shaft torque and the required right motor shaft torque are calculated based thereon. In addition, the distribution control unit 37 outputs a control signal to the left inverter 8 so that the left motor 6 generates the required left motor shaft torque, and also outputs a control signal to the right inverter 9 so that the right motor 7 generates the required right motor shaft torque. output a control signal to

[C. Combined use control (Part 1)]
FIG. 5 is a block diagram for explaining the processing contents of one of the programs (feedback/feedforward control section 40) executed by the motor control device 15. As shown in FIG. Reference numerals 41-46 in FIG. 5 are the same as the reference numerals 31-36 in FIG. 4, and reference numerals 48-50 in FIG. 5 are the same as the reference numerals 21-23 in FIG. The feedback/feedforward control unit 40 functions to correct the requested left shaft torque and the requested right shaft torque in the feedforward control unit 20 with a feedback correction amount.

A distribution control unit 47 (control unit) of the feedback/feedforward control unit 40 distributes the requested left shaft torque and the requested torque based on the requested left shaft torque, the requested right shaft torque, the damping torque, the feedback correction amount, and the driver requested torque. The right shaft torque is calculated. Here, as shown in FIG. 5, a value obtained by subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque, and a value obtained by adding the damping torque to the other are calculated. (required shaft torque difference) is calculated.

Further, the post-correction torque difference obtained by subtracting the feedback correction amount from the required shaft torque difference and the driver required torque are input to the distribution control unit 47 . The distribution control unit 47 calculates the requested left motor shaft torque and the requested right motor shaft torque based on the corrected torque difference and the driver requested torque. In addition, the distribution control unit 47 outputs a control signal to the left inverter 8 so that the left motor 6 generates the required left motor shaft torque, and also outputs a control signal to the right inverter 9 so that the right motor 7 generates the required right motor shaft torque. output a control signal to

[D. Combined use control (Part 2)]
FIG. 6 is a block diagram for explaining the processing contents of one of the programs (feedback/feedforward control section 60) executed by the motor control device 15. As shown in FIG. Reference numerals 41-46 in FIG. 6 are the same as the reference numerals 31-36 in FIG. 4, and reference numerals 49-50 in FIG. 6 are the same as the reference numerals 22-23 in FIG. The feedback/feedforward control unit 60 functions to correct the yaw motion required torque difference in the feedforward control unit 20 with a feedback correction amount.

The shaft drive torque calculator 48 of the feedback/feedforward control unit 60 calculates the requested left shaft torque and the requested right shaft torque based on the running state of the vehicle 10 and the feedback correction amount. As shown in FIG. 6, the shaft drive torque calculator 48 receives the driver's requested torque and the yaw motion requested torque difference minus the feedback correction amount. Therefore, the requested left shaft torque and the requested right shaft torque calculated here are values reflecting the feedback correction amount.

A motor shaft torque control unit 51 (control unit) controls the required left motor shaft torque and the required right motor shaft torque based on the required left shaft torque, which reflects the feedback correction amount, the required right shaft torque, and the damping torque. It calculates the shaft torque. Here, the requested left motor shaft torque and the requested right motor shaft torque are calculated based on the value obtained by subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque, and the value obtained by adding the damping torque to the other. torque is calculated.

In the present embodiment, the sum of the requested left shaft torque and the damping torque is the final shaft torque requested for the left shaft 3, and the damping torque is subtracted from the requested right shaft torque. is the shaft torque finally required for the right shaft 4 . In addition, the motor shaft torque control unit 51 outputs a control signal to the left inverter 8 so that the left motor 6 generates the required left motor shaft torque, and also outputs a right motor shaft torque so that the right motor 7 generates the required right motor shaft torque. A control signal is output to the inverter 9 .

[3. action, effect]
FIG. 7 is a graph showing torque oscillation when the above feedforward control and feedback control are not performed. This graph shows that torque oscillation occurs in the motors 6 and 7 when the torque difference between the left and right wheels 1 and 2 changes, and that the oscillation of the torque difference is difficult to converge. Such vibrations reduce the quietness and ride comfort in the passenger compartment.

On the other hand, FIG. 8 is a graph showing torque oscillation when the control by the feedback/feedforward control unit 40 shown in FIG. 5 is performed. By performing feedforward control and feedback control, the vibration state of the left shaft 3 and right shaft 4 is predicted, and the magnitude of the shaft torque of each motor 6 and 7 is fed back. As a result, the amplitude of the torque difference is reduced, and the actual torque difference converges with respect to the required torque difference in a short period of time, thereby improving the quietness and ride comfort in the passenger compartment.

(1) The feedback control unit 30 calculates the feedback correction amount based on the first rotation speed of the left motor 6 and the second rotation speed of the right motor 7 . Further, as shown in FIG. 4, the shaft torque of each motor 6, 7 is controlled based on the running state of the vehicle 10 and the feedback correction amount. With such control, it is possible to suppress vibration caused by the torque difference between the left and right wheels 1 and 2, and to improve the quietness and ride comfort of the vehicle 10. FIG.

(2) The feedback control unit 30 calculates the feedback correction amount so that the differential value of the difference between the first rotation speed and the second rotation speed becomes small. As a result, vibration caused by the torque difference between the left and right wheels 1 and 2 can be suppressed regardless of the difference in rotational speed between the motors 6 and 7 . For example, even when the vehicle 10 is turning, it is possible to suppress torque oscillation while maintaining a predetermined rotational speed difference.

(3) As shown in FIG. 4, by inputting the yaw motion required torque difference reflecting the feedback correction amount to the distribution control unit 37, the difference between the shaft torques output from the motors 6 and 7 can be easily calculated. can be adjusted to As a result, for example, torque distribution can be optimized while maintaining the driver-requested torque, and torque oscillation can be suppressed without changing the total driving force of the left and right wheels 1 and 2 .

(4) As shown in FIG. 5, the feedback/feedforward control unit 40 is provided with an axis drive torque calculation unit 48, a torque vibration estimation unit 49, and a damping torque calculation unit 50. A torque vibration is estimated and a damping torque is calculated. Further, the distribution control unit 47 calculates the requested left shaft torque and the requested right shaft torque based on the requested left shaft torque, the requested right shaft torque, the damping torque, the feedback correction amount, and the driver requested torque. In this way, by estimating the torque vibration based on the torque transmission model that models the resonance characteristics of the left and right axles 3 and 4, and then calculating the damping torque, the torque difference between the left and right wheels 1 and 2 can be derived. Vibration to be generated can be suppressed, and quietness and ride comfort of the vehicle 10 can be improved.

(5) In the feedback/feedforward control unit 40, the feedback correction amount is reflected in the difference between the shaft torques to which the damping torque is added or subtracted (that is, the required shaft torque difference). In this way, by setting the object to which the feedback correction amount is added or subtracted as the "required shaft torque difference", it is possible to suppress torque oscillation without changing the total required torque. In addition to this, subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque and adding it to the other can also contribute to suppressing torque oscillation without changing the total requested torque. .

(6) As shown in FIG. 3, the feedforward control unit 20 is provided with a drive torque calculation unit 21 for each shaft, a torque vibration estimation unit 22, and a damping torque calculation unit 23. is estimated and the damping torque is calculated. Further, the motor shaft torque control unit 24 calculates the requested left shaft torque and the requested right shaft torque based on the requested left shaft torque, the requested right shaft torque and the damping torque. In this way, by estimating the torque vibration based on the torque transmission model that models the resonance characteristics of the left and right axles 3 and 4, and then calculating the damping torque, the torque difference between the left and right wheels 1 and 2 can be derived. Vibration to be generated can be suppressed, and quietness and ride comfort of the vehicle 10 can be improved.

(7) The feedforward control unit 20 calculates a value obtained by subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque, and a value obtained by adding the damping torque to the other. With such control, for example, the torque distribution can be optimized while maintaining the driver's requested torque, and torque oscillation can be suppressed without changing the total driving force of the left and right wheels 1 and 2 .

(8) As shown in FIG. 6, the feedback/feedforward control section 60 includes elements 31 to 36 functioning as correction value calculation sections. Further, the motor shaft torque control section 51 controls the shaft torque of each motor 6, 7 based on the requested left shaft torque, the requested right shaft torque, the damping torque, and the feedback correction amount. In this way, by performing feedback control based on the rotational speed difference between the left and right motors 6, 7, it is possible to suppress vibrations caused by the torque difference between the left and right wheels 1, 2, and the quietness of the vehicle 10. and improve ride comfort.

(9) As shown in FIG. 6, the feedback/feedforward control unit 60 calculates the feedback correction amount so that the differential value of the difference between the first rotation speed and the second rotation speed becomes small. As a result, vibration caused by the torque difference between the left and right wheels 1 and 2 can be suppressed regardless of the difference in rotational speed between the motors 6 and 7 . For example, even when the vehicle 10 is turning, it is possible to suppress torque oscillation while maintaining a predetermined rotational speed difference.

(10) In the feedback/feedforward control section 60, as shown in FIG. 6, the feedback correction amount is reflected in the yaw motion required torque difference. As a result, for example, torque distribution can be optimized while maintaining the driver-requested torque, and torque oscillation can be suppressed without changing the total driving force of the left and right wheels 1 and 2 .

[4. Modification]
The above embodiment is merely an example, and there is no intention to exclude various modifications and application of techniques not explicitly described in this embodiment. Each configuration of this embodiment can be modified in various ways without departing from the gist thereof. Also, they can be selected or combined as needed.

In the above-described embodiment, the vehicle 10 in which the left and right wheels 1 and 2 are connected via the differential gear 5 is illustrated, but the differential gear 5 is not an essential element. For example, the motor control device 15 can be applied to an in-wheel motor type vehicle 10 as shown in FIG. If the vehicle 10 is equipped with at least the left motor 6 that transmits driving force to the left wheel 1 via the left shaft 3 and the right motor 7 that transmits driving force to the right wheel 2 via the right shaft 4, By applying the motor control device 15, the same functions and effects as those of the above-described embodiment can be obtained.

In the above-described embodiment, the control of the motors 6 and 7 that drive the left and right wheels 1 and 2 of the rear wheels of the vehicle 10 has been described in detail, but the control can also be applied to the front wheels. Moreover, it is applicable not only to electric vehicles but also to hybrid vehicles. Furthermore, the present invention can be applied not only to four-wheeled vehicles but also to three-wheeled vehicles, electric carts, senior cars (electric wheelchairs), and the like, and can also be applied to large vehicles such as trucks and buses.

[5. Note]
The following notes are disclosed with respect to embodiments including the above variations.
[Appendix 1]
a left motor that transmits driving force to the left wheel of the vehicle via the left shaft;
a right motor that transmits driving force to the right wheel of the vehicle via the right shaft;
a left rotation speed sensor for detecting a first rotation speed of the left motor;
a right rotation speed sensor for detecting a second rotation speed of the right motor;
A motor control system for a vehicle, comprising a computer containing a processor and a memory and controlling the left motor and the right motor based on the first rotation speed and the second rotation speed,
The computer
a correction value calculation unit that calculates a feedback correction amount for reducing torque oscillation of the left shaft and the right shaft based on the first rotation speed of the left motor and the second rotation speed of the right motor;
and a control unit that controls shaft torques of the left motor and the right motor based on the running state of the vehicle and the feedback correction amount.

[Appendix 2]
In the motor control system according to Appendix 1,
The correction value calculator calculates the feedback correction amount so that a differential value of a difference between the first rotation speed and the second rotation speed becomes small.

[Appendix 3]
In the motor control system according to Appendix 1 or 2,
The control section reflects the feedback correction amount on the required torque difference between the left shaft and the right shaft.

[Appendix 4]
In the motor control system according to any one of Appendices 1 to 3,
The computer
an each-shaft drive torque calculation unit that calculates a required left shaft torque that is the torque required for the left shaft and a required right shaft torque that is the torque required for the right shaft based on the running state of the vehicle;
Torque vibration for estimating torque vibration in each of the left shaft and the right shaft based on a torque transmission model modeling resonance characteristics of the left shaft and the right shaft, and the required left shaft torque and the required right shaft torque. an estimation unit;
a damping torque calculation unit that calculates a damping torque that reduces torque vibrations of the left shaft and the right shaft derived from the torque vibration,
The control unit controls shaft torques of the left motor and the right motor based on the requested left shaft torque, the requested right shaft torque, the damping torque, the feedback correction amount, and the driver requested torque.

[Appendix 5]
In the motor control system according to Appendix 4,
The controller controls the feedback correction amount to the shaft torque difference between a value obtained by subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque and a value obtained by adding the damping torque to the other. to control the shaft torque of the left motor and the right motor.

[Appendix 6]
a left motor that transmits driving force to the left wheel of the vehicle via the left shaft;
a right motor that transmits driving force to the right wheel of the vehicle via the right shaft;
an accelerator opening sensor that detects the accelerator opening of the vehicle;
a vehicle speed sensor that detects the vehicle speed of the vehicle;
a vehicle body posture control device that calculates a yaw motion required torque difference of the vehicle;
It incorporates a processor and memory, sets a driver requested torque based on the accelerator opening and the vehicle speed, and controls the left motor and the right motor based on the driver requested torque and the yaw motion requested torque difference. In a vehicle motor control system comprising a computer,
The computer
Each axis for calculating a required left shaft torque that is the torque required for the left shaft and a required right shaft torque that is the torque required for the right shaft based on the driver required torque and the yaw motion required torque difference a drive torque calculator;
Torque vibration for estimating torque vibration in each of the left shaft and the right shaft based on a torque transmission model modeling resonance characteristics of the left shaft and the right shaft, and the required left shaft torque and the required right shaft torque. an estimation unit;
a damping torque calculation unit that calculates a damping torque that reduces torque vibrations of the left shaft and the right shaft derived from the torque vibration;
a control unit that controls shaft torques of the left motor and the right motor based on the requested left shaft torque, the requested right shaft torque, and the damping torque.

[Appendix 7]
In the motor control system according to appendix 6,
The control unit controls the left motor and the right shaft torque based on a value obtained by subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque and a value obtained by adding the damping torque to the other. Controls the shaft torque of the motor.

[Appendix 8]
In the motor control system according to appendix 6 or 7,
The computer
a correction value calculation unit that calculates a feedback correction amount for reducing torque oscillation of the left shaft and the right shaft based on a first rotation speed of the left motor and a second rotation speed of the right motor;
The control unit controls shaft torques of the left motor and the right motor based on the requested left shaft torque, the requested right shaft torque, the damping torque, and the feedback correction amount.

[Appendix 9]
In the motor control system according to appendix 8,
The correction value calculator calculates the feedback correction amount so that a differential value of a difference between the first rotation speed and the second rotation speed becomes small.

[Appendix 10]
In the motor control system according to appendix 8 or 9,
The control section reflects the feedback correction amount on the shaft torque difference between the left shaft and the right shaft.

1 Left wheel 2 Right wheel 6 Left motor 7 Right motor 10 Vehicle 12 Accelerator opening sensor 13 Vehicle speed sensor 14 Body attitude control device 15 Motor control device 16 Left rotation speed sensor 17 Right rotation speed sensor 20 Feedforward control unit 21, 48 Each axis Drive torque calculators 22, 49 Torque vibration estimators 23, 50 Damping torque calculators 24, 51 Motor shaft torque controllers (controllers)
30 Feedback control units 31, 41 Drivetrain torsion model calculation units 32, 42 Differential calculation units 33, 43 Frequency filters 34, 44 Proportional term calculation units 35, 45 Integral term calculation units 36, 46 Differential term calculation units 37, 47 Distribution control part (control part)
40, 60 feedback/feedforward control unit

Claims (7)

A motor control device for a vehicle equipped with a left motor that transmits driving force to left wheels via a left shaft and a right motor that transmits driving force to right wheels via a right shaft,
A drive train torsion model that models torsional characteristics in power transmission paths between the left motor and the left shaft and between the right motor and the right shaft, a first rotational speed of the left motor, and the a drive train torsion model calculation unit that calculates a left shaft rotation speed and a right shaft rotation speed affected by the torsional vibration of the power transmission path using the second rotation speed of the right motor;
a correction value calculation unit that calculates a feedback correction amount for reducing torque vibration of the left shaft and the right shaft due to torsional vibration of the power transmission path based on the difference between the left shaft rotation speed and the right shaft rotation speed;
A motor control device, comprising: a control unit that controls shaft torques of the left motor and the right motor based on the feedback correction amount. 2. The motor control device according to claim 1, wherein the correction value calculation unit calculates the feedback correction amount such that a differential value of a difference between the left shaft rotation speed and the right shaft rotation speed becomes small. . The correction value calculation unit,
a differential calculation unit that calculates a differential value of a difference between the left shaft rotation speed and the right shaft rotation speed;
a frequency filter for extracting a predetermined frequency component from the differential value calculated by the differential operation unit;
a proportional term calculator that calculates a proportional term that is a correction amount proportional to the frequency component extracted by the frequency filter;
an integral term calculator that calculates an integral term that is a correction amount corresponding to the integral value of the frequency component extracted by the frequency filter;
a differential term calculator that calculates a differential term, which is a correction amount corresponding to a differential value of the frequency component extracted by the frequency filter,
The feedback correction amount is a sum of the proportional term, the integral term, and the differential term
3. The motor control device according to claim 2, characterized in that: The motor control device according to any one of claims 1 to 3, wherein the control section reflects the feedback correction amount on the required torque difference between the left shaft and the right shaft. a vehicle body posture control device for calculating, as the required torque difference, a yaw motion required torque difference, which is a torque difference between left and right wheels required to generate a yaw moment required for the vehicle;
The control unit generates the post-correction torque difference based on the post-correction torque difference obtained by subtracting the feedback correction amount from the yaw motion request torque difference calculated by the vehicle body posture control device and the driver request torque. Calculate the shaft torque of the left motor and the right motor as
5. The motor control device according to claim 4, characterized in that: an each-shaft drive torque calculation unit that calculates a required left shaft torque that is the torque required for the left shaft and a required right shaft torque that is the torque required for the right shaft based on the running state of the vehicle;
Torque vibration for estimating torque vibration in each of the left shaft and the right shaft based on a torque transmission model modeling resonance characteristics of the left shaft and the right shaft, and the required left shaft torque and the required right shaft torque. an estimation unit;
a damping torque calculation unit that calculates a damping torque that reduces torque vibrations of the left shaft and the right shaft derived from the torque vibration,
The control unit controls the shaft torques of the left motor and the right motor based on the driver requested torque, the requested left shaft torque, the requested right shaft torque, the damping torque, and the feedback correction amount. The motor control device according to any one of claims 1 to 5 , wherein the The controller controls the feedback correction amount to the shaft torque difference between a value obtained by subtracting the damping torque from one of the requested left shaft torque and the requested right shaft torque and a value obtained by adding the damping torque to the other. 7. The motor control device according to claim 6 , wherein the shaft torques of said left motor and said right motor are controlled based on the reflection of .

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