JP2021145413A - Drive control device for wheel independent drive type car - Google Patents

Abstract

To provide a drive control device capable of suppressing destabilization of behavior of a car due to an output torque difference on left and right drive wheels, and preventing an excessive load applied to a power device.SOLUTION: A drive control device is applied for a car comprising a plurality of motors 6 which can independently drive left and right wheels. A motor drive controller 22 comprises: a maximum torque calculation part 35 for calculating a maximum torque value which can be output using rotation speed of the motor 6; and a torque restriction part 36 for restricting torque of the motor 6 using the calculated maximum torque value. The maximum torque calculation part 35 calculates a maximum torque value which can be output from, on the basis of rotation speed of each motor 6, out of the left and right motors, when a car speed is equal to or less than a predetermined value. When the car speed is greater than the predetermined speed, the maximum torque calculation part calculates a maximum torque value common to both of left and right wheels, using a higher rotation speed, out of rotation speeds calculated by the left and right motors 6.SELECTED DRAWING: Figure 3

Description

The present invention relates to a wheel-independent drive vehicle drive control device that controls a motor-driven vehicle having a motor capable of left-right independent drive for at least one of the left and right drive wheels of the front and rear wheels.

Conventionally, there is a motor-driven vehicle having a motor capable of independently driving left and right with respect to at least one of the left and right drive wheels of the front and rear wheels. Patent Document 1 has been proposed as a drive control device for such a vehicle.
In the disclosed technology of the same document, the maximum torque is calculated from the motor rotation speed of the higher of the left and right drive wheels, and the maximum torque is limited.

JP-A-2017-135903

In a wheel-independent vehicle, the rotation speed of the left and right drive wheels is due to the difference in tire diameter due to tire wear and air pressure, the detection error of the rotation speed, and whether it is on the inner ring side or the outer ring side during turning. Difference occurs.
On the other hand, due to the characteristics of the motor, the maximum torque that can be output calculated from the rotation speed of the motor varies greatly in the range AB in FIG. Therefore, when one wheel or both wheels are in the vicinity of the rotation speeds A and B in the AB region and there is a difference in the rotation speeds of the motors of the left and right drive wheels, a large difference occurs in the maximum torque that can be output. When both wheels are driven with their respective maximum torques, the behavior of the vehicle may become unstable.
Further, when turning, the rotation speed of the outer ring of turning becomes faster, so that the maximum torque on the outer ring side becomes smaller, which tends to cause understeer.

In the technique disclosed in Patent Document 1, the maximum torque is calculated from the motor rotation speed of the higher of the left and right drive wheels, and the torque of both wheels is limited by the maximum torque.
However, in reality, in the region where the motor rotates from no rotation to extremely low rotation, the maximum torque is lowered at ^{0 min -1 (point C) to reach point D as shown in Fig. 10 in order to protect the power device of the inverter.} A CD region is provided in which the maximum torque is gradually increased as the rotation speed is increased. If the maximum torque is simply calculated at the higher rotation speed as in Patent Document 1, the motor at the extremely low rotation speed and lower rotation speed from the stopped state is set to the maximum torque that cannot be output originally, and is a power device. There is a possibility of giving an excessive load to the.

An object of the present invention is to provide a wheel-independent drive vehicle capable of suppressing destabilization of vehicle behavior due to a difference in output torque between the left and right drive wheels and preventing an excessive load from being applied to a power device. It is to provide a drive control device.

All of the drive control devices of the first to third wheel independent drive type vehicles of the present invention are used.
Wheel-independent drive type equipped with a plurality of motors 6 and 6 capable of independently driving left and right and a motor drive control device 22 for controlling these motors 6 and 6 for at least one of the front and rear wheels, left and right drive wheels 2 and 2. It is a vehicle drive control device
The motor drive control device 22 is calculated by the maximum torque calculation unit 35 that calculates the maximum torque value that can be output by the motors 6 and 6 using the rotation speeds of the motors 6 and 6, and the maximum torque calculation unit 35. It is provided with a torque limiting unit 36 that limits the torque of the motor by using the maximum torque value.
The wheel-independent drive type vehicle is, for example, a vehicle provided with an in-wheel motor drive device or a two-motor on-horde type vehicle.

In the first wheel independent drive vehicle drive control device of the present invention,
The maximum torque calculation unit 35
If the vehicle speed is below a certain value, the maximum torque value that can be output is calculated from the rotation speeds of the left and right motors 6 and 6 respectively.
When the vehicle speed is higher than the predetermined value, the maximum torque value common to both the left and right wheels is calculated by using the higher rotation speed of the rotation speeds calculated for each of the left and right motors 6 and 6.

According to this configuration, when the vehicle speed is higher than the predetermined vehicle speed, the maximum torque calculation unit 35 uses the higher rotation speed even if there is a difference in the rotation speeds of the motors of the left and right drive wheels 2 and 2. The output torque values of both wheels 2 and 2 are limited by the calculated maximum torque. Therefore, even if the maximum torque command is output to the motors 6 and 6 of the two wheels 2 and 2, there is no difference in the actual drive torque, and the behavior of the vehicle does not become unstable. That is, the torque of the inner ring of turning does not increase unintentionally due to the motor output characteristics. If one wheel slips, the maximum torque values of both wheels 2 and 2 are limited in the downward direction, so that the operation is on the safe side.
When the vehicle speed is less than or equal to the specified vehicle speed, the maximum torque is calculated at the rotation speeds of the left and right motors 2 and 2, so that the maximum torque that can be originally output is also calculated for the maximum torque of the motor 6 having a low rotation speed. .. In the prior art, since the maximum torque is calculated at the higher rotation speed, the maximum torque that cannot be output may be calculated. However, the present invention calculates such a maximum torque that cannot be output. Never. Therefore, it is possible to prevent an excessive load from being applied to the power device.
Here, the "certain vehicle speed" is set to a place higher than the region where the maximum torque of extremely low rotation (for example, a vehicle speed of 10 km / h or less) is low from the stopped state.
If the vehicle speed is low, the vehicle is unlikely to become unstable even if a torque difference occurs between the left and right, so the maximum torque that both wheels 2 and 2 can originally output can be obtained, and climbing performance and acceleration performance can be ensured.
The vehicle speed may be a value detected by the vehicle speed sensor or may be calculated from the rotation speed of the motor 6.
The battery voltage is used in addition to the rotation speed to calculate the maximum torque of the motor 6. The same applies to the second and third drive control devices.

In the second wheel independent drive vehicle drive control device of the present invention,
The maximum torque calculation unit 35
If at least one of the rotation speeds of the left and right motors 6 and 6 is equal to or less than a predetermined value, the maximum torque value that can be output is calculated from the rotation speeds of the left and right motors 6 and 6. death,
When the rotation speeds of both the left and right motors 6 and 6 are higher than the specified values, the maximum common to both the left and right wheels is used by using the higher rotation speed of the rotation speeds calculated for each of the left and right motors 6 and 6. Calculate the torque value.

In the case of this configuration, the vehicle speed condition in the first drive control device is controlled as the rotation speed condition. That is, if the motor rotation speeds of both wheels both exceed the specified rotation speeds, the maximum torque is calculated using the higher rotation speed, and if either one is less than or equal to the specified rotation speeds, each of the two wheels is used. The maximum torque is calculated from the rotation speed of.
In the case of this configuration as well, the same effect as that of the drive control device of the first wheel independent drive type vehicle can be obtained.

In the third wheel independent drive vehicle drive control device of the present invention,
The maximum torque calculation unit 35
The maximum torque value is calculated at the rotation speed calculated by each of the left and right motors 6 and 6, and the smaller maximum torque value of these two maximum torque values is set as the maximum torque value common to both the left and right wheels.

In the case of this configuration, the smaller maximum torque value among the maximum torques calculated at the left and right rotation speeds is set as the common maximum torque value. In this case, the maximum torque that cannot be output is not set even in the region of extremely low rotation from the stopped state. Therefore, it is possible to prevent the behavior of the vehicle from becoming unstable due to the difference in output torque between the left and right drive wheels, and it is possible to prevent an excessive load from being applied to the power device.

In the first to third motor drive control devices of the present invention, the maximum torque value calculation unit 35 calculates the maximum torque value of each of the motors from the rotation speeds of the left and right motors 6 and 6 when traveling straight. It may be calculated.
When going straight, the vehicle is unlikely to become unstable even if there is a difference in drive torque between the left and right, so by calculating the maximum torque value from the rotation speed of each motor 6 and 6 when going straight, the maximum that both wheels can originally output. Torque can be produced.
The above-mentioned "straight ahead" includes the case of traveling on a curved road having a minute curvature such as an expressway.

In the motor drive control device having each configuration of the present invention, the torque maximum value calculation unit 35 is the information communicated from the higher-level control means 21 for the motor drive control device, or the traveling state detected by the detection means of the vehicle. The function of calculating any of the above maximum torque values may be invalidated based on the above information, and the respective maximum torque values may be calculated based on the respective rotation speeds of the left and right motors 6 and 6.

In a left-right independent drive type vehicle, if the command torque is the maximum torque or a torque close to the maximum torque when turning, the torque on the outer ring side unintentionally drops below the torque on the inner ring side due to the difference in rotation speed, and the vehicle becomes unstable. It is an object of the present invention to prevent this from happening. If the command torque is sufficiently smaller than the maximum torque required from the rotation speed, the torque as commanded can only be output, and even if the command is smaller than the torque on the outer ring side than the torque on the inner ring side. Even if it is, there is no problem because it is the intended torque difference.

Further, in the left and right independent drive type vehicles, the torque commands of the inner ring and the outer ring may be intentionally different for turning assistance and spin suppression. The torque command on the inner ring side may be larger than the torque command on the outer ring side, and when the common maximum torque is calculated at the higher rotation speed or the torque is limited at the lower maximum torque as in the present invention. In addition, it is conceivable that the torque that can be originally output is limited and the functions of the turning assist and the spin suppression are affected. Therefore, the calculation of the common maximum torque in the present invention is invalidated by communication, running conditions, etc., that is, by information communicated from the host control means 21, or information on running conditions detected by the detection means of the vehicle. It is good to have a function to do. When performing turning assistance or spin control as described above, the function in the present invention is invalidated, the maximum torque of each is calculated by the rotation speeds of the left and right motors, and the command torque is limited by the maximum torque of each.

In the motor drive control device having each configuration of the present invention, the motor 6 is a wheel bearing 7 that supports the motor 6, the drive wheel 2, and the wheel bearing 7 by decelerating the rotation of the motor. It may be a motor 6 that constitutes an in-wheel motor drive device 17 including a speed reducer to transmit.
In the case of a vehicle traveling by an in-wheel motor drive device, the prevention of destabilization of vehicle behavior by applying the invention is more effectively exhibited.

The drive control device for a wheel-independent drive vehicle of the present invention can suppress destabilization of vehicle behavior due to the difference in output torque between the left and right drive wheels, and can give an excessive load to the power device. Can be prevented.

It is a block diagram which shows the conceptual structure of the vehicle to which the drive control device of the wheel independent drive type vehicle which concerns on one Embodiment of this invention is applied. It is a vertical cross-sectional view of an example of an in-wheel motor drive device of the vehicle. It is a block diagram which shows the conceptual structure of the drive control device of the wheel independent drive type vehicle. It is a flowchart which shows the control of the drive control device of the wheel independent drive type vehicle which concerns on 1st Embodiment. It is a flowchart which shows the control of the drive control device of the wheel independent drive type vehicle which concerns on 2nd Embodiment. It is a flowchart which shows the control of the drive control device of the wheel independent drive type vehicle which concerns on 3rd Embodiment. It is a block diagram which shows the conceptual structure of another wheel independent drive type vehicle to which the drive control device which concerns on one Embodiment of this invention is applied. It is a block diagram which shows the conceptual structure of the other wheel independent drive type vehicle to which the drive control device which concerns on one Embodiment of this invention is applied. It is a graph which shows the relationship example of the rotation speed of a motor, and the maximum torque. It is a graph which shows the relationship example of the rotation speed of a motor, and the maximum torque at the time of controlling a small torque in an extremely low rotation region. It is a graph which shows an example of the relationship between a rotation speed, a maximum torque, and a drive battery voltage.

A drive control device for a wheel-independent drive vehicle according to a first embodiment of the present invention (hereinafter, may be simply referred to as a “drive control device”) will be described with reference to FIGS. 1 to 4. This embodiment corresponds to claims 1, 4, and 6.
As shown in FIG. 1, in this vehicle 1, the left and right rear wheels are driven wheels 2 and 2 individually driven by electric motors 6 and 6, respectively, and the front wheels are steered by a steering device 4. It is a rear-wheel two-wheel drive vehicle with driving wheels 3 and 3. The steering device 4 is operated by a steering operating means 5 such as a steering wheel. Each of the traveling motors 6 and 6 constitutes an in-wheel motor drive device 17 (FIG. 2) described later. Each drive wheel 2 and driven wheel 3 are provided with a brake 19 that generates a braking force by operating a brake command means 16 such as a brake pedal.

FIG. 2 is a cross-sectional view schematically showing the configuration of the in-wheel motor drive device 17. Each in-wheel motor drive device 17 has a motor 6, a speed reducer 12, and a wheel bearing 7, and a part or all of them is arranged in the drive wheel 2. The rotation of the motor 6 is transmitted to the drive wheels 2 via the speed reducer 12 and the wheel bearings 7. A brake rotor 8 constituting the brake 19 is fixed to the flange portion of the hub wheel 7a of the wheel bearing 7, and the brake rotor 8 rotates integrally with the drive wheel 2. The motor 6 is, for example, an embedded magnet type synchronous motor in which a permanent magnet is built in the core portion of the rotor 6a. The motor 6 shown is a motor provided with a radial gap between the stator 6b fixed to the housing 9 and the rotor 6a attached to the rotary output shaft 10. The motor 6 may be an AC motor such as another type of synchronous motor or induction motor.

The control system will be described. As shown in FIG. 1, the vehicle 1 is equipped with a drive control device 20 including an ECU 21 and a motor drive control device 22.
The ECU 21 is a vehicle control ECU that performs integrated control of the entire automobile, and is a higher-level control means that gives a command to the motor drive control device 22. In the case of an electric vehicle, the ECU 21 is also referred to as a VCU (vehicle control unit). The ECU 21 is composed of a microcomputer, a program executed by the microcomputer, an electronic circuit, and the like.
The motor drive control device 22 is a means for applying a drive current to the traveling drive motors 6 and 6 in response to a command torque sent from the ECU 21, and includes an inverter device. The motor drive control device 22 includes motor individual drive units 22b and 22b individually provided for each of the motors 6 and 6, and a common control unit 22a which is an upper control unit of both motor individual drive units 22b and 22b. Become. The ECU 21 and the motor drive control device 22 are connected to each other so that signals can be transmitted to each other by a controller area network (abbreviation: CAN) communication or the like.

An accelerator command output from an accelerator command means 15 such as an accelerator pedal and a brake command output from a brake command means 16 such as a brake pedal are input to the ECU 21. The accelerator command is also called an accelerator opening signal. The accelerator command means 15 and the brake command means 16 may be an automatic driving control device or a driving support device (not shown) provided in the ECU 21 or above the ECU 21.

As shown in FIG. 3, the ECU 21 includes a command torque calculation unit 47 and a torque distribution means 48. The command torque calculation unit 47 calculates the total command torque for driving both the motors 6 and 6 in response to the accelerator command and the brake command. The torque distribution means 48 distributes the command torque calculated by the command torque calculation unit 47 to both motors 6 and 6 according to the set conditions and the detected information. The torque distribution means 48 may have a function of giving a difference to the command torques given to the motors 6 and 6 for turning assistance and spin suppression.

The ECU 21 includes a vehicle speed detecting means 54 that detects the vehicle speed from the detection signal of the vehicle speed sensor 55, a steering angle detecting means 51 that detects the steering angle from the detection signal of the steering angle sensor 50, and a steering angle sensor 52. The steering angle detecting means 53 for detecting the steering angle is connected. The steering angle detecting means 51 constitutes a part of the steering operating means 5 of FIG.
Further, the motor drive control device 22 inputs detection signals such as control torque and motor rotation speed, and other control information to the ECU 21. In addition to the command torque, information such as vehicle speed, steering, and steering is input from the ECU 21 to the motor drive control device 22. The motor drive control device 22 uses the input command torque, vehicle speed, steering and steering information for control. Specific description of the use of steering and steering information will be omitted.

The motor drive control device 22 includes an inverter device as described above, and includes power circuit units 28, 28 provided for each motor 6 and one motor control unit 29 that controls these power circuit units 28, 28. Consists of. The power circuit units 28 and 28 include an inverter 31 that converts the DC current of the battery 18 (see FIG. 1) into an AC current for driving the motor 6 that is an AC motor, a current command output from the motor control unit 29, and the like. It is a driver circuit that controls the power of the inverter 31 according to the drive command of, for example, a PMW driver 32.

The motor control unit 29 has motor drive control units 30 and 30 provided for the individual motors 6 and 6 and the common control unit 22a, and corresponds to each of the motor drive control units 30 and 30. The motor individual control units 22b and 22b are configured by the power circuit units 28 and 28.
Each motor drive control unit 30 is a means for generating a current command for driving the motor 6 according to a given command torque and outputting it to the PWM driver 32 of the power circuit unit 28, and detects the drive current of each motor 6. It has a control function for improving efficiency according to the phase angle of the motor, such as torque control, by using the detected current value of the current sensor 38.

In the drive control device for a wheel-independent drive vehicle having such a configuration, the motor control unit 29 is provided with a maximum torque calculation unit 35 and a torque limit unit 36 as means for forming the common control unit 22a, and both left and right wheels. Left and right rotation speed detection units 34, 34 that detect the motor rotation speed from the detection angles of the rotation angle sensors 33, 33 of the motors 6, 6 and the drive battery detection unit 37 that detects the voltage of the battery 18 (see FIG. 1). And are provided. Since the fluctuation of the rotation speed of the motor 6 is large, the rotation speed detection units 34 and 34 may calculate the average value of the rotation speed for a certain period and output it as the rotation speed.

The torque limiting unit 36 basically has a function of outputting command torques for the left and right motors 6 and 6 commanded by the upper control means ECU 21 to the motor drive control units 30 and 30 of the corresponding left and right wheels. The output of the command torque to the left and right motors 6 and 6 is limited by the maximum torque value calculated by the maximum torque calculation unit 35.

When the vehicle speed is equal to or less than a predetermined value, the maximum torque calculation unit 35 calculates the maximum torque value that can be output from the respective rotation speeds of the left and right motors 6 and 6, and the vehicle speed is determined. If it is higher than the value, the maximum torque value common to both the left and right wheels is calculated using the higher rotation speed of the rotation speeds calculated for each of the left and right motors 6 and 6.
Since the maximum torque value also changes depending on the drive battery voltage, the maximum torque calculation unit 35 specifically calculates the maximum torque using the drive battery voltage detected by the drive battery voltage detection unit 37 in addition to the rotation speed. ..
Here, the "certain vehicle speed" is higher than the region where the maximum torque of extremely low rotation (for example, a vehicle speed of 10 km / h or less) is low from the stopped state, for example, in the vicinity of the point (1) in FIG. Set.
The vehicle speed may be a value detected by the vehicle speed sensor 55 or may be calculated from the rotation speed of the motor 6.
In order to calculate the maximum torque value using the rotational speed of the motor 6, information that defines the relationship between the rotational speed, the drive voltage, and the maximum torque (for example, FIGS. 10 and 11) according to the characteristics of the motor 6 is provided. A means (not shown) stored in a map or the like is provided, and the rotation speed and the drive battery voltage are calculated in light of the related information. The same applies hereinafter.

Further, the maximum torque calculation unit 35 determines whether or not the vehicle is traveling straight, and when the vehicle is traveling straight, calculates the maximum torque value of the motors 6 and 6 from the rotation speeds of the left and right motors 6 and 6.

FIG. 4 is a flowchart of processing performed by the maximum torque calculation unit 35.
The maximum torque calculation unit 35 first determines whether or not the vehicle speed is equal to or lower than the "determined vehicle speed" (step S1).
When it is equal to or less than the "determined vehicle speed" (steps S1 and Yes), the maximum torque value of each of the left and right motors 6 and 6 is calculated individually using the respective rotation speeds of the left and right wheel motors 6 and 6 (steps S1, Yes). Step S4).
If the vehicle speed is not less than or equal to the vehicle speed specified in step S1 (steps S1 and No), it is determined whether or not the vehicle is going straight (step S2).
When traveling straight (steps S1 and Yes), the process proceeds to step S4, and the maximum torque values of the left and right motors 6 and 6 are calculated individually using the respective rotation speeds of the left and right motors 6 and 6.
When not going straight (steps S2 and No), the common maximum torque value is calculated by using the larger of the rotation speeds of the left and right wheel motors 6 and 6.

The torque limiting unit 36 of FIG. 3 limits the command torque output to the motor drive control units 30 and 30 of the left and right wheels with the maximum torque value calculated by the maximum torque calculating unit 35 in this way.

According to the configuration of this embodiment, when the vehicle speed is higher than the predetermined vehicle speed, the maximum torque calculation unit 35 is higher than the predetermined vehicle speed even if there is a difference in the rotation speeds of the motors of the left and right drive wheels 2 and 2. The output torque values of both wheels 6 and 6 are limited by the maximum torque calculated by the rotation speed. Therefore, even if the maximum torque command is output to both wheels 6 and 6, there is no difference in the actual driving torque, and the behavior of the vehicle does not become unstable. That is, the torque of the inner ring of turning does not increase unintentionally due to the motor output characteristics. If one wheel slips, the maximum torque values of both wheels 6 and 6 are limited in the downward direction, so that the operation is on the safe side.
When the vehicle speed is less than the specified vehicle speed, the maximum torque is calculated at the rotation speeds of the left and right motors 6 and 6, so the maximum torque that can be originally output is also set for the maximum torque of the motor 6 with a low rotation speed. .. In the prior literature, since the maximum torque is calculated at the higher rotation speed, the maximum torque that cannot be output may be calculated, but in this embodiment, such a maximum torque that cannot be output is calculated. There is nothing to do.
If the vehicle speed is low, the vehicle 1 is unlikely to become unstable even if a torque difference occurs between the left and right, so the maximum torque that both wheels 6 and 6 can originally output can be obtained, and climbing performance and acceleration performance can be ensured. .. Further, it is possible to prevent an excessive load from being applied to a power device such as a switching element constituting the inverter 31.

Since the torque maximum value calculation unit 35 calculates the maximum torque value of each of the motors 6 and 6 from the rotation speeds of the left and right motors 6 and 6 when traveling straight, the following effects can be obtained. In other words, when going straight, the vehicle is unlikely to become unstable even if there is a difference in drive torque between the left and right, so by calculating the maximum torque value from the rotation speed of each motor 6 and 6 when going straight, both wheels can originally output. Maximum torque can be produced.
The above-mentioned "straight ahead" includes the case of traveling on a curved road having a minute curvature such as an expressway.

The drive control device according to the second embodiment will be described with reference to FIGS. 1, 3, and 5. The second embodiment corresponds to claims 2, 4, and 6.
In this embodiment, how the maximum torque value calculation unit 35 in FIG. 3 determines to calculate the maximum torque value is determined by using the vehicle speed in the first embodiment. As described above, the determination is made based on the rotation speed of the motor, and the other aspects are the same as those of the drive control device according to the first embodiment.
In the second embodiment, the maximum torque calculation unit 35 is
If at least one of the rotation speeds of the left and right motors 6 and 6 is equal to or less than a predetermined value, the maximum torque value that can be output is calculated from the rotation speeds of the left and right motors 6 and 6. death,
When the rotation speeds of both the left and right motors 6 and 6 are higher than the specified values, the maximum common to both the left and right wheels is used by using the higher rotation speed of the rotation speeds calculated for each of the left and right motors 6 and 6. Calculate the torque value.

Also in this embodiment, the maximum torque calculation unit 35 determines whether or not the vehicle is going straight, and when the vehicle is going straight, calculates the maximum torque value of the motors 6 and 6 from the rotation speeds of the left and right motors 6 and 6. do.

FIG. 5 is a flowchart of processing performed by the maximum torque calculation unit 35.
The maximum torque calculation unit 35 first determines whether or not the condition that "at least one of the left and right motors 6 and 6 is equal to or less than a predetermined rotation speed" is satisfied (step R1).
When the rotation speed is equal to or lower than the specified rotation speed (steps R1 and Yes), the maximum torque value of each of the left and right motors 6 and 6 is calculated individually using the respective rotation speeds of the left and right wheel motors 6 and 6 (step). R4).
When the condition is not satisfied in step R1 (steps R1 and No), it is determined whether or not the vehicle is going straight (step R2).
When traveling straight (steps R2 and Yes), the process proceeds to step S4, and the maximum torque values of the left and right motors 6 and 6 are calculated individually using the respective rotation speeds of the left and right motors 6 and 6.
When not going straight (steps R2 and No), the common maximum torque value is calculated by using the higher rotation speed of the left and right wheel motors 6 and 6.

In the case of this embodiment, what was determined by the vehicle speed condition in the first embodiment is controlled as the rotation speed condition. That is, when the rotation speeds of the motors 6 and 6 of both wheels both exceed the specified rotation speeds, the maximum torque is calculated using the higher rotation speed, and one of them is equal to or less than the specified rotation speed. At the time of, the maximum torque is calculated by the rotation speed of each of the two wheels.
In this case as well, the same effect as that of the first embodiment can be obtained.

The drive control device according to the third embodiment will be described with reference to FIGS. 1, 3, and 6. The third embodiment corresponds to claims 3, 4, and 6.
In this embodiment, the maximum torque value calculation unit 35 in FIG. 3 calculates the maximum torque value as follows, and other than that, it is the same as the drive control device according to the first embodiment. ..
In this embodiment, the maximum torque calculation unit 35 in FIG. 3 is
The maximum torque value is calculated at the rotation speed calculated by each of the left and right motors 6 and 6, and the smaller maximum torque value of these two maximum torque values is set as the maximum torque value common to both the left and right wheels.

FIG. 6 is a flowchart in which the maximum torque calculation unit 35 calculates the maximum torque value in this embodiment.
First, it is determined whether or not the vehicle is going straight (step T1).
When traveling straight (steps T1 and Yes), the maximum torque value is calculated individually using the respective rotation speeds of the left and right wheel motors 6 and 6.
When the vehicle is not traveling straight in step T1 (steps T1 and No), the smaller of the two maximum torque values calculated from the rotation speeds of the left and right wheel motors 6 and 6 is set as the common maximum torque value.

In the case of this configuration, as described above, the smaller maximum torque value of the maximum torques calculated at the left and right rotation speeds is set as the common maximum torque value. In this case, the maximum torque that cannot be output is not set even in the region of extremely low rotation from the stopped state. Therefore, it is possible to prevent an excessive load from being applied to the power device.

In each of the above-described embodiments, the torque maximum value calculation unit 35 has any of the above information based on the information communicated from the higher-level control means 21 for the motor drive control device or the information on the traveling condition detected by the detection means of the vehicle. The function of calculating the maximum torque value may also be disabled, and the maximum torque value may be calculated based on the rotation speeds of the left and right motors 6 and 6.
The information communicated from the upper control means 21 is, for example, information that the torque commands of the inner ring and the outer ring are different for turning assistance and spin suppression, and the torque commands of the inner ring and the outer ring are different. This is information that prohibits the calculation of the maximum torque value common to all. The detected running condition information is information such as slip of the drive wheel 2 and skidding of the vehicle.

In a left-right independent drive type vehicle, if the command torque is the maximum torque or a torque close to the maximum torque when turning, the torque on the outer ring side unintentionally drops below the torque on the inner ring side due to the difference in rotation speed, and the vehicle becomes unstable. It is the purpose of this embodiment to prevent this from happening. If the command torque is sufficiently smaller than the maximum torque required from the rotation speed, the torque as commanded can only be output, and even if the command is smaller than the torque on the outer ring side than the torque on the inner ring side. Even if it is, there is no problem because it is the intended torque difference.

Further, in the left and right independent drive type vehicles, the torque commands of the inner ring and the outer ring may be intentionally different for turning assistance and spin suppression. The torque command on the inner ring side may be larger than the torque command on the outer ring side, and as in this embodiment, the common maximum torque is calculated at the higher rotation speed, or the torque is limited by the lower maximum torque. In some cases, it is conceivable that the torque that can be originally output is limited and these functions are affected. Therefore, it is preferable to have a function of invalidating the calculation of the common maximum torque in each of the above-described embodiments depending on communication, running conditions, and the like. When performing turning assistance or spin control as described above, the function of calculating the maximum torque in each of the above embodiments is invalidated, the maximum torque is calculated according to the rotation speeds of the left and right motors, and the command torque is calculated at each maximum torque. To limit.

In each of the above embodiments, the case where the vehicle is applied to a rear-wheel two-wheel drive vehicle has been described. However, the vehicle may be applied to a front-wheel two-wheel drive vehicle as shown in FIG. 7, or a four-wheel drive vehicle as shown in FIG. May be applied to cars.

Further, in each of the above embodiments, the maximum torque calculation unit 35 and the torque limit unit 36 are provided in the motor drive control device 22, but the maximum torque calculation unit 35 and the torque limit unit 36 may be provided in the ECU 21.
The vehicle 1 has been described with respect to an example in which the in-wheel motor drive device 17 is mounted, but the vehicle may be a wheel-independent drive type vehicle and may be a two-motor on-board type vehicle.

Although the embodiments for carrying out the present invention have been described above based on the embodiments, the embodiments disclosed this time are exemplary in all respects and are not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 ... Vehicle, 2 ... Drive wheel, 3 ... Drive wheel, 4 ... Steering device, 5 ... Steering operation means, 6 ... Motor, 7 ... Wheel bearing, 12 ... Reducer, 17 ... In-wheel motor drive device, 18 ... Battery, 19 ... Brake, 20 ... Drive control device, 21 ... ECU, 22 ... Motor drive control device, 28 ... Power circuit unit, 29 ... Motor control unit, 30 ... Motor drive control unit, 31 ... Inverter, 32 ... PMW Driver, 33 ... Rotation angle sensor, 34 ... Rotation angle detection unit, 35 ... Maximum torque calculation unit, 36 ... Torque limit unit, 38 ... Current sensor, 47 ... Command torque calculation unit, 48 ... Torque distribution means, 50 ... Steering angle Sensor, 51 ... Steering angle detecting means, 52 ... Steering angle sensor, 53 ... Steering angle detecting means, 54 ... Vehicle speed detecting means, 55 ... Vehicle speed sensor

Claims (6)

It is a drive control device for a wheel-independent drive vehicle equipped with a plurality of motors capable of independently driving left and right for at least one of the left and right drive wheels of the front and rear wheels and a motor drive control device for controlling these motors.
The motor drive control device uses the rotation speed of the motor to calculate the maximum torque value that can be output by the motor, and the maximum torque value calculated by the maximum torque calculation unit to calculate the maximum torque value of the motor. Equipped with a torque limiter that limits the torque of
The maximum torque calculation unit is
If the vehicle speed is below a certain value, the maximum torque value that can be output is calculated from the rotation speeds of the left and right motors.
When the vehicle speed is higher than the specified value, the maximum torque value common to both the left and right wheels is calculated using the higher rotation speed of the rotation speeds calculated for each of the left and right motors.
A drive control device for a wheel-independently driven vehicle. It is a drive control device for a wheel-independent drive vehicle equipped with a plurality of motors capable of independently driving left and right for at least one of the left and right drive wheels of the front and rear wheels and a motor drive control device for controlling these motors.
The motor drive control device uses the rotation speed of the motor to calculate the maximum torque value that can be output by the motor, and the maximum torque value calculated by the maximum torque calculation unit to calculate the maximum torque value of the motor. Equipped with a torque limiter that limits the torque of
The maximum torque calculation unit is
If at least one of the rotation speeds of the left and right motors is equal to or less than a predetermined value, the maximum torque value that can be output is calculated from the rotation speeds of the left and right motors.
When the rotation speeds of both the left and right motors are higher than the predetermined values, the maximum torque value common to both the left and right wheels is calculated using the higher rotation speed of the rotation speeds calculated for each of the left and right motors.
A drive control device for a wheel-independently driven vehicle. It is a drive control device for a wheel-independent drive vehicle equipped with a plurality of motors capable of independently driving left and right for at least one of the left and right drive wheels of the front and rear wheels and a motor drive control device for controlling these motors.
The motor drive control device uses the rotation speed of the motor to calculate the maximum torque value that can be output by the motor, and the maximum torque value calculated by the maximum torque calculation unit to calculate the maximum torque value of the motor. Equipped with a torque limiter that limits the torque of
The maximum torque calculation unit is
The maximum torque value of each is calculated at the rotation speed calculated by each of the left and right motors, and the smaller maximum torque value of these two maximum torque values is set as the maximum torque value common to both the left and right wheels.
A drive control device for a wheel-independently driven vehicle. In the motor drive control device according to any one of claims 1 to 3, the torque maximum value calculation unit determines the maximum torque value of each of the left and right motors from the rotation speeds of the left and right motors when traveling straight. Wheel independent drive vehicle drive control device to calculate. In the drive control device for the wheel-independent drive vehicle according to any one of claims 1 to 4, the torque maximum value calculation unit is the information communicated from the higher-level control means for the motor drive control device, or Wheel independent drive that disables the function of calculating any of the above maximum torque values based on the information on the driving conditions detected by the detection means of the vehicle, and calculates the maximum torque value based on the respective rotation speeds of the left and right motors. Drive control device for type vehicles. In the motor drive control device for a wheel-independent drive vehicle according to any one of claims 1 to 5, the motor includes the motor, wheel bearings that support the drive wheels, and the motor. A drive control device for a wheel-independent drive vehicle that constitutes an in-wheel motor drive device that includes a speed reducer that reduces rotation and transmits the speed to the wheel bearings.

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