JP6955437B2 - Vehicle control device and vehicle control method - Google Patents

Description

The present invention relates to a vehicle control device and a vehicle control method.

Conventionally, in Patent Document 1 below, when it is determined that the reference time is T0 or more, the drive torque of the motor determined to be the reference time T0 or more is reduced from the reference torque Trq0, and the other motor is used. It is described that the required torque Trqd is satisfied by increasing the driving torque of the above.

Japanese Unexamined Patent Publication No. 2012-95378

However, in the technique described in the above patent document, the driving torque of one of the front motor and the rear motor is reduced and the driving torque of the other motor is increased, so that the front and rear driving force distribution changes significantly. There is a problem that it ends up. Therefore, there is a problem that the driver unexpectedly behaves and the vehicle behavior becomes unstable.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to suppress overload of motors for driving front wheels and rear wheels, and to stabilize vehicle behavior. It is an object of the present invention to provide a new and improved vehicle control device and a vehicle control method which are possible.

In order to solve the above problems, according to a certain viewpoint of the present invention, the first motor that generates the driving force of the front wheels of the vehicle is controlled, and the first motor is limited to the maximum rated torque that can be generated by the first motor. A first motor control unit that can switch between a first mode in which the motor is operated and a second mode in which the first motor is operated with a continuous rated torque lower than the maximum rated torque as the upper limit, and the rear wheels of the vehicle. The first mode in which the second motor that generates the driving force of the above is controlled and the second motor is operated with the maximum rated torque that can be generated by the second motor as the upper limit, and the continuous rated torque that is lower than the maximum rated torque. A second motor control unit capable of switching between a second mode for operating the second motor and a second mode for operating the second motor is provided as an upper limit, and the first motor control unit and the second motor control unit include the first motor and the first motor. When the operation of at least one of the two motors is switched from the first mode to the second mode, the other operation of the first motor and the second motor is also switched from the first mode to the second mode. , Vehicle control device is provided.

The first motor control unit may switch the operation of the first motor from the first mode to the second mode when the operating state of the first motor is overloaded.

Further, when the first motor control unit receives information indicating that the first motor is overloaded from the inverter that controls the first motor, the operation of the first motor is performed from the first mode to the first mode. When the second motor control unit receives the information indicating that the first motor is overloaded from the inverter that controls the first motor, the second motor control unit switches to the second mode. The operation of the two motors may be switched from the first mode to the second mode.

Further, the second motor control unit may switch the operation of the second motor from the first mode to the second mode when the operating state of the second motor is overloaded.

Further, when the second motor control unit receives information indicating that the second motor is overloaded from the inverter that controls the second motor, the operation of the second motor is performed from the first mode to the first mode. When the mode is switched to two modes and the second motor control unit receives the information indicating that the second motor is overloaded from the inverter that controls the second motor, the first motor control unit receives the information indicating that the second motor is overloaded. The operation of one motor may be switched from the first mode to the second mode.

Further, the first motor control unit starts the operation of the first motor from the first mode when the state in which the first motor is operated at the maximum rated torque exceeds a predetermined allowable operation duration. It may be switched to the second mode.

Further, the second motor control unit starts the operation of the first motor from the first mode when the state in which the second motor is operated at the maximum rated torque exceeds a predetermined allowable operation duration. It may be switched to the second mode.

Further, the first motor control unit is in a state where the temperature, current value, or voltage value of the first motor exceeds a predetermined threshold value when the first motor is operated in the first mode. May switch the operation of the first motor from the first mode to the second mode when is continued for a predetermined time or longer.

Further, the second motor control unit is in a state where the temperature, current value, or voltage value of the second motor exceeds a predetermined threshold value when the second motor is operated in the first mode. May switch the operation of the second motor from the first mode to the second mode when is continued for a predetermined time or longer.

Further, it may be provided with a notification control unit that controls to notify that both the first motor and the second motor have been switched from the first mode to the second mode.

Further, the maximum rated torque may be a torque whose duration is limited when the first motor or the second motor is operated at the maximum rated torque.

Further, the continuous rated torque may be a torque whose duration is not limited when the first motor or the second motor is operated at the continuous rated torque.

Further, in order to solve the above problems, according to another viewpoint of the present invention, the first motor that generates the driving force of the front wheels of the vehicle and the second motor that generates the driving force of the rear wheels of the vehicle are The step of determining whether or not there is an overload, and the maximum rated torque that can be generated by the one motor when at least one of the first motor and the second motor is determined to be overloaded. The step of switching from the first mode in which the one motor is operated with the upper limit to the second mode in which the one motor is operated with the continuous rated torque lower than the maximum rated torque as the upper limit, and the first motor and the first When the other of the two motors is also operated in the first mode in which the maximum rated torque that can be generated is used as the upper limit, the step of switching to the second mode in which the continuous rated torque lower than the maximum rated torque is used as the upper limit is used. And, a vehicle control method is provided.

As described above, according to the present invention, it is possible to suppress the overload of the motors that drive the front wheels and the rear wheels, and to stabilize the vehicle behavior.

It is a schematic diagram which shows the structure of the vehicle which concerns on one Embodiment of this invention. It is a schematic diagram which shows the structure of a control device and its surroundings in detail. It is a schematic diagram which shows the output characteristic of the motor of a front wheel. It is a schematic diagram which shows the output characteristic of the motor of a rear wheel. It is a flowchart which shows the process procedure in the control device of this embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

First, the configuration of the vehicle 500 according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic view showing a configuration of a vehicle 500 according to an embodiment of the present invention. As shown in FIG. 1, in the vehicle 500, the four tires (wheels) 12, 14, 16, 18 of the front wheels and the rear wheels, the control device (controller) 100, the outside world recognition unit 200, and the tires 12, 14 of the front wheels rotate. The driving force of the motor 20, the motor 22 that controls the rotation of the rear wheel tires 16 and 18, the inverter 19 that controls the motor 20, the inverter 21 that controls the motor 22, and the driving force of the motor 20 to the tires 12 and 14. The wheel speed (vehicle speed) is detected from the rotations of the gearbox 23 and the drive shaft 24 to be transmitted, the gearbox 25 and the drive shaft 26 to transmit the driving force of the motor 22 to the tires 16 and 18, and the tires 12 and 14 of the front wheels. Wheel speed sensors 40, 42, wheel speed sensors 28, 30 that detect wheel speed (vehicle speed) from the rotation of each tire 16, 18 of the rear wheels, accelerator opening sensor 32, steering wheel 34 that steers front wheels 12, 14. , Steering angle sensor 35 that detects the steering angle δ of the steering wheel, power steering mechanism 36, display device 38, speaker 39, temperature sensor 44 that detects the temperature of the front wheel motor 20, and detects the temperature of the rear wheel motor 22. It is configured to have a temperature sensor 46.

The configuration shown in FIG. 1 includes one motor 20 for driving the front wheels and one motor 22 for driving the rear wheels, but the configuration is not limited to this, and each of the four wheels is provided. A driving motor and a gearbox corresponding to each motor may be provided.

In the present embodiment, the control device 100 calculates the control driving force of the motors 20 and 22, and the control device 100 instructs the motors 20 and 22 to control the motors 20 and 22 in a coordinated manner.

FIG. 2 is a schematic diagram showing in detail the configuration of the control device 100 and its surroundings. As shown in FIG. 2, the control device 100 includes a traveling control unit 150 that controls the front and rear motors 20 and 22, and a notification control unit 160 that controls to notify an occupant such as a driver of a warning. .. The travel control unit 150 includes a first motor control unit 110, a second motor control unit 120, and a driving force distribution unit 140.

Therefore, the first motor control unit 110 acquires an overload protection flag from the inverter 19 indicating that the operating state of the motor 20 is an overload state and protection of the motor 20 is required. Similarly, the second motor control unit 120 acquires an overload protection flag from the inverter 21 indicating that the operating state of the motor 22 is an overload state and protection of the motor 22 is required. The first motor control unit 110 and the second motor control unit 120 so as to operate both the motors 20 and 22 in the continuous rated mode when the overload protection flag is issued for any of the motors 20 and 22. Take control.

Hereinafter, the control performed by the control device 100 will be specifically described. When the driving force distribution unit 140 of the control device 100 acquires the accelerator opening from the accelerator opening sensor 32, it calculates the total required driving force of the vehicle 500 and transfers the total driving force to the front wheel motor 20 and the rear wheel motor 22. Allocate. The first motor control unit 110 sends a command value of the required driving force to the inverter 19 that controls the front wheel motor 20. The inverter 19 controls the front wheel motor 20 based on the command value of the required driving force of the front wheel motor 20. The second motor control unit 120 sends a command value of the required driving force to the inverter 21 that controls the rear wheel motor 22. The inverter 21 controls the rear wheel motor 22 based on the command value of the required driving force of the rear wheel motor 22. As a result, each of the motors 20 and 22 is controlled according to the required driving force.

FIG. 3 is a schematic view showing the output characteristics of the front wheel motor 20. Further, FIG. 4 is a schematic view showing the output characteristics of the rear wheel motor 22. 3 and 4 show the relationship between the driving force (vertical axis: torque) and the speed (horizontal axis: rotation speed) of the front wheel motor 20 or the rear wheel motor 22.

The operation modes of the motors 20 and 22 include a maximum rated mode and a continuous rated mode. In the maximum rated mode, the maximum torque value (maximum rated torque) that the motor can exert can be output, but the duration of the maximum torque value is limited. When the motor is used in the maximum rated mode, the amount of heat generated inside increases, which affects the deterioration of the motor and the like. Therefore, in the maximum rated mode, the duration (allowable time) of the maximum torque value is defined. On the other hand, in the continuous rated mode, the torque value is limited as compared with the maximum rated mode, and the torque value (continuous rated torque) capable of continuously outputting for a long time is set as the upper limit. 3 and 4 show the torque characteristics for each of the maximum rated mode and the continuous rated mode.

Here, in a situation where the motors 20 and 22 are overloaded, for example, when the driver wants to enjoy sports driving, the motors 20 and 22 may overheat. In such a case, for example, the heat generation of the motors 20 and 22 can be suppressed by switching to the control in the continuous rating mode based on the temperatures of the motors 20 and 22 detected by the temperature sensors 44 and 46. However, if the maximum rated mode is switched to the continuous rated mode in this way, the outputs of the motors 20 and 22 will suddenly go down, and the driver will not be able to perform the expected operation, or unexpectedly. There is a concern that vehicle behavior will occur and the behavior of the vehicle 500 will become unstable. In particular, if the specifications of the front and rear motors 20 and 22 are different, or if the loads applied to the front and rear motors 20 and 22 are not equal, one of the motors tends to overheat and the output may suddenly drop. .. Further, it is assumed that the vehicle behavior becomes unstable when one of the motors is switched from the maximum rated mode to the continuous rated mode and then returned to the maximum rated mode again.

In the present embodiment, since the motors 20 and 22 can be controlled independently, the stability of the vehicle 500 can be improved by optimally controlling the front-rear distribution of torque between the front wheel motor 20 and the rear wheel motor 22. Can be done. In particular, in the present embodiment, when one of the front wheel motor 20 and the rear wheel motor 22 falls from the maximum rated mode to the continuous rated mode, the other of the front wheel motor 20 and the rear wheel motor 22 also shifts from the maximum rated mode. Control to drop to continuous rated mode.

As shown in FIG. 3, the front wheel motor 20 is driven in the maximum rated mode, and is driven by the torque (maximum rated torque) and the rotation speed indicated by the point A. Further, as shown in FIG. 4, the rear wheel motor 20 is driven in the maximum rated mode, and is driven by the torque (maximum rated torque) and the rotation speed indicated by the point A. In this case, if the operation of the front wheel motor 20 in the maximum rated mode exceeds the allowable range (allowable operation duration), the front wheel motor 20 is overloaded. In this case, the inverter 19 sends information (overload protection flag) indicating that an overload is applied to the first motor control unit 110.

Whether or not the motors 20 and 22 are in an overloaded state is determined based on the allowable operation duration described above, as well as various parameters (temperature, current value, voltage value, etc.) indicating the operating state of the motors 20 and 22. Can be determined according to the duration. For example, when the temperature of the motors 20 and 22 exceeds a predetermined threshold value exceeds the allowable duration, it is determined that the motors 20 and 22 are in an overloaded state. Further, when the state in which the current values of the motors 20 and 22 exceed a predetermined threshold value exceeds the allowable duration, it is determined that the motors 20 and 22 are in an overloaded state. Similarly, when the state in which the voltage values of the motors 20 and 22 exceed a predetermined threshold value exceeds the allowable duration, it is determined that the motors 20 and 22 are in an overloaded state. In either case, the overload protection flag is sent to the first motor control unit 110 or the second motor control unit 120.

In the determination based on the various parameters described above, the determination may be performed using any one parameter, or the determination may be performed by combining a plurality of parameters. Further, by sending these parameters to the control device 100 via CAN (Control Area Network) or the like, the control device 100 may make a determination.

When the first motor control unit 110 receives the overload protection flag from the inverter 19, the first motor control unit 110 controls to lower the front wheel motor 20 from the maximum rated mode to the continuous rated mode. As a result, the front wheel motor 20 is driven by the torque (continuous rated torque) and the number of revolutions indicated by the point B in FIG. Further, the first motor control unit 110 sends information to the second motor control unit 120 that the front wheel motor 20 has been dropped from the maximum rated mode to the continuous rated mode.

When the second motor control unit 120 receives information from the first motor control unit 110 that the front wheel motor 20 has been dropped from the maximum rated mode to the continuous rated mode, the second motor control unit 120 changes the rear wheel motor 22 from the maximum rated mode to the continuous rated mode. Drop it in. As a result, the rear wheel motor 22 is driven by the torque (continuous rated torque) and the number of revolutions indicated by the point B in FIG.

In the above description, when the front wheel motor 20 is dropped from the maximum rated mode to the continuous rated mode, the rear wheel motor 22 is dropped from the maximum rated mode to the continuous rated mode as an example. Similarly, when the rear wheel motor 22 is dropped from the maximum rated mode to the continuous rated mode, control is performed so that the front wheel motor 20 is dropped from the maximum rated mode to the continuous rated mode.

If the overload protection flag is not issued from any of the inverters 19 and 21, the operation of the motors 20 and 22 is continued without changing the operation modes of the front and rear motors 20 and 22.

As described above, when the motor 20 is driven with the maximum rated torque, the amount of heat generated inside the motor 20 increases, which causes deterioration of the motor. Therefore, deterioration of the motor 20 can be suppressed by changing the operation mode of the motor 20 from the maximum rated mode to the continuous rated mode in response to the acquisition of the overload protection flag from the inverter 19.

In particular, when the specifications of the front wheel motor 20 and the rear wheel motor 22 are different, or when the front and rear torque distribution is not evenly controlled, an overload protection flag may be issued for one of the motors 20. In such a case, if only one of the motors 20 is dropped from the maximum rated mode to the continuous rated mode, the front and rear torque distribution will change, the driver will not be able to drive as expected, or unexpected vehicle behavior will occur. there's a possibility that.

In the present embodiment, when one of the front wheel motor 20 and the rear wheel motor 22 is switched from the maximum rated mode to the continuous rated mode, the other of the front wheel motor 20 and the rear wheel motor 22 is also continuously rated from the maximum rated mode. Controls to switch to the mode. As a result, even if one motor switches from the maximum rated mode to the continuous rated mode, the other motor also switches from the maximum rated mode to the continuous rated mode at the same time, so that the front and rear torque distribution does not change significantly. , It is possible to maintain the behavioral stability of the vehicle 500.

Further, when one of the front wheel motor 20 and the rear wheel motor 22 is switched from the maximum rated mode to the continuous rated mode, the other of the front wheel motor 20 and the rear wheel motor 22 is also switched from the maximum rated mode to the continuous rated mode. Then, the total driving force of the vehicle 500 decreases. Therefore, the notification control unit 160 displays a warning on the display device 38 indicating that the total driving force is reduced when both the motors 20 and 22 are dropped from the maximum rated mode to the continuous rated mode. Take control. Further, the notification control unit 160 controls the speaker 39 to sound a warning indicating that the total driving force is decreasing.

As a result, the driver can recognize that the total driving force of the vehicle 500 decreases, so that the vehicle 500 can be driven in an optimum driving state according to the decrease in the driving force.

The warning can be displayed on the display device 38 by any display method. Further, the warning sound from the speaker 39 can be sounded by any voice. For example, by displaying "Operating in motor protection mode" or the like on the display device 38 and pronouncing that fact from the speaker 39, the driver is informed that the total driving force is reduced and the driver is alerted. Can be done.

As described above, the present embodiment is not limited to the configuration including one motor 20 for driving the front wheels and one motor 22 for driving the rear wheels, and each of the four wheels is included. A driving motor may be provided. Even in this case, when the motor driving the front wheels is switched from the maximum rated mode to the continuous rated mode, the behavior of the vehicle 500 is stabilized by switching the motor driving the rear wheels from the maximum rated mode to the continuous rated mode. Can be made to.

Next, the processing procedure in the control device 100 of the present embodiment will be described based on the flowchart of FIG. The process of FIG. 5 is performed at predetermined control cycles. First, in step S10, the state of the overload protection flag sent from the inverter 19 and the inverter 21 is confirmed. In the next step S11, it is determined whether or not the overload protection flag has been sent from at least one of the inverter 19 and the inverter 21. Then, if the overload protection flag is sent, the process proceeds to step S12. On the other hand, if the overload protection flag is not sent, the process waits in step S11.

In step S12, it is determined whether or not any of the front and rear motors 20 and 22 is operating in the maximum rated mode, and if any motor is operating in the maximum rated mode, the process proceeds to step S14. .. In step S14, both the front and rear motors 20 and 22 are operated in the continuous rated mode.

After step S14, the process proceeds to step S16, a warning indicating that the total driving force is decreasing is displayed on the display device 38, and the warning is sounded from the speaker 39. After step S16, the process is temporarily terminated.

If any motor is not operating in the maximum rated mode in step S12, the process is temporarily terminated without changing the operation modes of the motors 20 and 22.

As described above, according to the present embodiment, when one of the front wheel motor 20 and the rear wheel motor 22 exceeds the allowable range of the maximum rated mode and falls from the maximum rated mode to the continuous rated mode, the other motor Also controls to drop from the maximum rated mode to the continuous rated mode. As a result, it is possible to suppress deterioration of the motor exceeding the permissible range of the maximum rated mode, and to maintain the steering stability of the vehicle 500 without causing a large change in the torque distribution in the front-rear direction.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

19, 21 Inverter 20, 22 Motor 100 Control device 110 1st motor control unit 120 2nd motor control unit 106 Driving force distribution control unit 500 Vehicle

Claims (13)

The first mode in which the first motor that generates the driving force of the front wheels of the vehicle is controlled and the first motor is operated with the maximum rated torque that can be generated by the first motor as the upper limit, and the continuous lower than the maximum rated torque. A first motor control unit that can switch between a second mode in which the first motor is operated with the rated torque as the upper limit, and a first motor control unit that can switch between the first motor and the second mode.
The first mode in which the second motor that generates the driving force of the rear wheels of the vehicle is controlled and the second motor is operated with the maximum rated torque that can be generated by the second motor as the upper limit, and the maximum rated torque It is provided with a second motor control unit that can switch between a second mode in which the second motor is operated with a low continuous rated torque as an upper limit.
The first motor control unit and the second motor control unit perform the first mode when the operation of at least one of the first motor and the second motor is switched from the first mode to the second mode. A vehicle control device, characterized in that the operation of the motor and the other of the second motor is also switched from the first mode to the second mode. 1. The first motor control unit is characterized in that, when the operating state of the first motor is overloaded, the operation of the first motor is switched from the first mode to the second mode. The vehicle control device described in. When the first motor control unit receives information indicating that the first motor is overloaded from the inverter that controls the first motor, the operation of the first motor is performed from the first mode to the second mode. Switch to,
When the first motor control unit receives the information indicating that the first motor is overloaded from the inverter that controls the first motor, the second motor control unit operates the second motor. The vehicle control device according to claim 2, wherein the first mode is switched to the second mode. The second motor control unit is characterized in that, when the operating state of the second motor is overloaded, the operation of the second motor is switched from the first mode to the second mode. The vehicle control device described in. When the second motor control unit receives information indicating that the second motor is overloaded from the inverter that controls the second motor, the operation of the second motor is performed from the first mode to the second mode. Switch to,
When the first motor control unit receives the information indicating that the second motor is overloaded from the inverter that controls the second motor, the first motor control unit operates the first motor. The vehicle control device according to claim 4, wherein the first mode is switched to the second mode. The first motor control unit performs the operation of the first motor from the first mode to the first mode when the state in which the first motor is operated at the maximum rated torque exceeds a predetermined allowable operation duration. The vehicle control device according to any one of claims 1 to 5, wherein the vehicle is switched to two modes. The second motor control unit performs the operation of the first motor from the first mode to the first mode when the state in which the second motor is operated at the maximum rated torque exceeds a predetermined allowable operation duration. The vehicle control device according to any one of claims 1 to 5, wherein the vehicle is switched to two modes. The first motor control unit determines a state in which the temperature, current value, or voltage value of the first motor exceeds a predetermined threshold value when the first motor is operated in the first mode. The vehicle control device according to any one of claims 1 to 7, wherein the operation of the first motor is switched from the first mode to the second mode when the operation of the first motor is continued for a certain period of time or longer. The second motor control unit determines a state in which the temperature, current value, or voltage value of the second motor exceeds a predetermined threshold value when the second motor is operated in the first mode. The vehicle control device according to any one of claims 1 to 8, wherein the operation of the second motor is switched from the first mode to the second mode when the operation of the second motor is continued for a certain period of time or longer. 15. The vehicle control device according to any one. The maximum rated torque according to any one of claims 1 to 10, wherein the maximum rated torque is a torque whose duration is limited when the first motor or the second motor is operated at the maximum rated torque. Vehicle control device. The continuous rated torque according to any one of claims 1 to 11, wherein the continuous rated torque is a torque whose duration is not limited when the first motor or the second motor is operated at the continuous rated torque. Vehicle control device. A step of determining whether or not the first motor that generates the driving force of the front wheels of the vehicle and the second motor that generates the driving force of the rear wheels of the vehicle are overloaded.
A first mode in which when at least one of the first motor and the second motor is determined to be overloaded, the one motor is operated up to the maximum rated torque that can be generated by the one motor. To the step of switching to the second mode in which one of the motors is operated with the continuous rated torque lower than the maximum rated torque as the upper limit.
When the first motor and the other of the second motors are also operated in the first mode in which the maximum rated torque that can be generated is the upper limit, the operation is performed with the continuous rated torque lower than the maximum rated torque as the upper limit. And the step to switch to the second mode
A vehicle control method, characterized in that the vehicle is provided with.

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