JP2021035128A - Motor control deice and motor control method - Google Patents

Abstract

To provide a motor control device and a motor control method which can improve turning performance of a vehicle.SOLUTION: A motor control device according to one aspect of an embodiment comprises a motor control part. The motor control part individually controls motors for rotationally driving attached to left and right driving wheels respectively of a vehicle. Further, the motor control part, when performing turning of the vehicle, executes first turning control by which the motor for an inner wheel is controlled so that first negative torque is applied to the inner wheel which is positioned inside during the turning of the vehicle of the left and right wheels and the motor is controlled so that second negative torque smaller than the first negative torque is applied to the inner wheel after the first negative torque is applied to the inner wheel.SELECTED DRAWING: Figure 1B

Description

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

Conventionally, various motor control devices have been proposed for controlling rotary drive motors attached to the left and right drive wheels of a vehicle (see, for example, Patent Document 1). In the above-mentioned conventional technique, the vehicle is turned by controlling the motors individually.

JP-A-2007-106171

However, there is room for further improvement in the prior art in terms of improving the turning performance of the vehicle.

The present invention has been made in view of the above, and an object of the present invention is to provide a motor control device and a motor control method capable of improving the turning performance of a vehicle.

In order to solve the above problems and achieve the object, the present invention includes a motor control unit in the motor control device. The motor control unit individually controls the rotary drive motors attached to the left and right drive wheels of the vehicle. Further, when the vehicle is turned, the motor control unit controls the motor of the inner wheels so as to apply a first negative torque to the inner wheels of the left and right drive wheels that are inside when the vehicle is turned. After applying the first negative torque to the inner ring, the first turning control is executed, which controls the motor so as to apply a second negative torque smaller than the first negative torque to the inner ring.

According to the present invention, the turning performance of the vehicle can be improved.

FIG. 1A is a diagram showing an outline of a motor control method according to an embodiment. FIG. 1B is a diagram showing an outline of a motor control method according to an embodiment. FIG. 2 is a block diagram showing a configuration of a motor control device according to an embodiment. FIG. 3A is a diagram showing a vehicle before the execution of the first turning control. FIG. 3B is a diagram showing a vehicle after the execution of the first turning control. FIG. 4 is a flowchart showing an example of a processing procedure executed by the motor control device.

Hereinafter, embodiments of the motor control device and the motor control method disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

In the following, first, the outline of the motor control method according to the embodiment will be described with reference to FIGS. 1A and 1B. 1A and 1B are diagrams schematically showing an outline of a motor control method according to an embodiment.

As shown in FIG. 1A, the vehicle C is, for example, a four-wheeled vehicle having four drive wheels 50. In the following, the left front driving wheel 50 of the vehicle C is "left front wheel 50FL", the right front driving wheel 50 is "right front wheel 50FR", the left rear driving wheel 50 is "left rear wheel 50RL", and the right rear driving wheel. 50 may be described as "right rear wheel 50RR". The number of drive wheels 50 is not limited to the example of FIG. 1A. That is, the number of drive wheels 50 may be three or less, or five or more, as long as they are at least on the left and right sides of the vehicle C. Further, it is not necessary that all the wheels provided in the vehicle C are driving wheels, and for example, the driving wheels may be only the front wheels or only the rear wheels.

The motor control device 10 and the motor 60 are mounted on the vehicle C. The motors 60 are attached to the drive wheels 50, respectively, and drive the drive wheels 50 to rotate. That is, there are a plurality of motors 60, and each of the drive wheels 50 of the vehicle C is rotationally driven. In the following, the motor 60 attached to the left front wheel 50FL is referred to as the "left front wheel motor 60FL", the motor 60 attached to the right front wheel 50FR is referred to as the "right front wheel motor 60FR", and the motor 60 attached to the left rear wheel 50RL is referred to as the motor 60. The motor 60 attached to the "left rear wheel motor 60RL" and the right rear wheel 50RR may be referred to as the "right rear wheel motor 60RR".

The motor control device 10 can individually control the motor 60. For example, the motor control device 10 can control each motor 60 by outputting a command value corresponding to an operation amount of an accelerator pedal (not shown) to the motor 60. By the control of the motor 60, the motor 60 is rotationally driven, the drive wheels 50 rotate with the rotation of the motor 60, and the vehicle travels.

In the motor control device 10 according to the present embodiment, the turning performance of the vehicle C is improved by appropriately controlling the motor 60 described above.

More specifically, when the steering wheel 51 is operated by a driver (not shown) to request turning of the vehicle C, for example, the left front wheel 50FL and the right front wheel 50FR are steered in the turning direction. In the example of FIG. 1A, the left front wheel 50FL and the right front wheel 50FR are steered toward the right side of the vehicle C, and the vehicle C makes a right turn indicated by an arrow A. Here, it is assumed that the vehicle C is turned while traveling at a low speed.

The motor control device 10 according to the present embodiment determines whether or not the driver desires (desires) a rapid turn. For example, in the motor control device 10, when the vehicle speed is less than the predetermined speed and the steering operation amount of the steering 51 is operated to the predetermined maximum amount or the vicinity of the predetermined maximum amount, the driver rapidly makes a U-turn or the like. It is determined that a smooth turn is desired.

It should be noted that the above-mentioned condition for determining that the driver desires a rapid turn is merely an example and is not limited. That is, for example, in addition to the above-mentioned conditions, a navigation device, a camera, or the like may be used to make the surroundings of the vehicle a place where a sharp turn such as a U-turn is possible, or other conditions. It may be.

Then, as shown in FIG. 1B, the motor control device 10 determines that the driver desires a sharp turn, and when the vehicle C is turned, the motor control device 10 is inside the left and right drive wheels 50 when the vehicle is turned. The inner ring motor (right rear wheel motor 60RR in the example of FIG. 1B) is controlled so that the first negative torque D1 is applied to the inner ring (right rear wheel 50RR in the example of FIG. 1B).

Here, the first negative torque D1 is a torque in the direction of stopping the inner ring (right rear wheel 50RR), and more specifically, is a negative torque that causes a slip state in the inner ring.

As a result, the inner ring that has been rotated due to the low-speed running of the vehicle C is in a slip state (including a substantially slip state). Then, when the inner ring is in the slip state, the wheel and the road surface are separated from each other, so that the rotation speed of the inner ring rapidly decreases due to the applied negative torque regardless of the traveling speed of the vehicle C. After that, when the rotation speed of the inner ring drops to a certain rotation speed (for example, a rotation speed close to 0 rotation speed), the inner ring shifts from the slip state to the grip state, but when it is at a low rotation speed, it is in a state of gripping with the road surface. Therefore, the inner ring is in a state in which the rotation is stopped (including a state in which the rotation is almost stopped). Therefore, the vehicle C can turn with the inner ring whose rotation has stopped as the fulcrum B, the turning radius of the vehicle C can be reduced, and thus the turning performance of the vehicle C can be improved.

Here, the motor control device 10 can control the motor 60 so that the drive torque (total drive torque) of the vehicle C as a whole does not decrease by applying the first negative torque D1 to the inner ring. ..

Specifically, when the motor control device 10 applies a negative torque (for example, the first negative torque D1) to the inner ring, the outer ring (left in the example of FIG. 1B) which is the outer ring of the left and right drive wheels 50 when the vehicle turns. The outer wheel motor 60 (left rear wheel motor 60RL in the example of FIG. 1B) is controlled so that the positive torque E1 is applied to the rear wheel 50RL). The positive torque E1 is set to, for example, the required torque amount required for the vehicle C. Alternatively, the positive torque E1 may be a value obtained by adding the same torque amount as the absolute value of the negative torque applied to the inner ring to the torque amount previously applied as a positive torque to the outer ring.

As a result, it is possible to suppress a decrease in the drive torque (total drive torque) of the vehicle C as a whole, and it is possible to make it less likely to give a sense of discomfort to the driver, for example, and the drive torque on the outer ring side is the inner ring. Since it is larger than the above, it is possible to increase the turning amount.

Further, the motor control device 10 controls the motor 60 by applying the second negative torque D2 to grip the inner ring whose rotation has stopped or almost stopped on the road surface (in other words, to keep the grip state). be able to.

Specifically, the motor control device 10 applies a first negative torque D1 to the inner ring (right rear wheel 50RR) and then applies a second negative torque D2 smaller than the first negative torque D1 to the inner ring. Controls the motor 60 (right rear wheel motor 60RR).

As a result, it is possible to prevent the inner ring from rotating in the reverse direction and rotating in the reverse direction from the state where the inner ring is gripped on the road surface and stopped, and the stopped state can be maintained. That is, the state in which the inner ring functions as the fulcrum B can be maintained, so that the vehicle C can be turned more reliably with the inner ring as the fulcrum B.

In the following, when the vehicle C is turned as described above, the first negative torque D1 is applied to the inner ring, the first negative torque D1 is applied, and then the second negative torque D2 is applied to the inner ring. The turning control that controls the motor 60 so as to be performed may be described as "first turning control".

Further, as described above, the motor control device 10 applies the first negative torque D1 to the inner ring when the vehicle C is traveling at a low speed, specifically, when the speed of the vehicle C is less than a predetermined speed. The inner ring motor 60 is controlled in this way, in other words, the first turning control is executed. Conversely, the motor control device 10 prohibits the execution of the first turning control when the speed of the vehicle C is equal to or higher than a predetermined speed. The predetermined speed is a relatively small value that can be determined that the vehicle C is traveling at a low speed, and is an example of the first speed.

As a result, for example, when the vehicle is traveling at a low speed, the turning control according to the present embodiment is performed, so that the occurrence of vehicle spin or the like that may occur when the vehicle makes a sharp turn during the traveling at a high speed is surely prevented. It becomes possible.

Next, the configuration of the motor control device 10 according to the embodiment will be described in detail with reference to FIG. FIG. 2 is a block diagram showing a configuration of the motor control device 10 according to the embodiment. Note that, in FIG. 2, only the components necessary for explaining the features of the present embodiment are represented by functional blocks, and the description of general components is omitted.

In other words, each component shown in FIG. 2 is a functional concept and does not necessarily have to be physically configured as shown in the figure. For example, the specific form of distribution / integration of each functional block is not limited to the one shown in the figure, and all or part of the functional blocks are functionally or physically distributed in arbitrary units according to various loads and usage conditions. -It is possible to integrate and configure.

As shown in FIG. 2, the motor control device 10 is connected to a rotation speed sensor 40, a steering angle sensor 41, a vehicle speed sensor 42, a yaw rate sensor 43, and each motor 60.

The rotation speed sensor 40 is a sensor that detects the rotation speeds of the four motors 60. The steering angle sensor 41 is a sensor that detects the amount of steering operation of the steering 51 (see FIG. 1A). The vehicle speed sensor 42 is a sensor that detects the speed of the vehicle C. The yaw rate sensor 43 is a sensor that detects the turning speed of the vehicle C. The rotation speed sensor 40, the steering angle sensor 41, the vehicle speed sensor 42, and the yaw rate sensor 43 each output a signal indicating a detection result to the motor control device 10.

The motor 60 is connected to the drive wheels 50 (see FIG. 1A) and rotationally drives the drive wheels 50. As the motor 60, an in-wheel motor can be used. Further, the motor 60 is controlled based on a command value input from the motor control device 10.

The motor control device 10 includes a control unit 20 and a storage unit 30. The control unit 20 includes a detection unit 21, a turning determination unit 22, a motor control unit 23, and a notification unit 24.

The control unit 20 includes, for example, a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output port, and various circuits.

The CPU of the computer functions as a detection unit 21, a turning determination unit 22, a motor control unit 23, and a notification unit 24 of the control unit 20, for example, by reading and executing a program stored in the ROM.

Further, at least a part or all of the detection unit 21, the turning determination unit 22, the motor control unit 23, and the notification unit 24 of the control unit 20 are hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). It can also be configured with hardware.

Further, the storage unit 30 is, for example, a rewritable non-volatile memory such as a data flash or an HDD (Hard Disk Drive), or a storage device such as a register, and stores various programs and information.

The detection unit 21 of the control unit 20 detects the rotation speed of the drive wheels 50 based on the signal output from the rotation speed sensor 40. Further, the detection unit 21 detects the steering operation amount of the steering 51 based on the signal output from the steering angle sensor 41. Further, the detection unit 21 detects the vehicle speed based on the signal output from the vehicle speed sensor 42. Further, the detection unit 21 detects the yaw rate based on the signal output from the yaw rate sensor 43.

The detection unit 21 notifies the motor control unit 23 of the detected rotation speed, vehicle speed, yaw rate, etc. of the drive wheels 50. Further, the detection unit 21 notifies the turning determination unit 22 of the detected steering operation amount and the like.

The turn determination unit 22 determines whether or not the driver desires a rapid turn. Such a turn may be a state in which the vehicle C is actually turning, or a state before the vehicle C starts turning, in other words, a state in which the vehicle C is about to start turning. ..

For example, the turning determination unit 22 determines that the driver desires a rapid turning based on the vehicle speed and the amount of steering operation. Specifically, for example, in the turning determination unit 22, when the vehicle speed is less than the predetermined speed and the steering operation amount is equal to or more than the predetermined operation amount (more specifically, the predetermined maximum amount), the driver desires a rapid turn. Is determined. The turning determination unit 22 notifies the motor control unit 23 of the determination result.

The motor control unit 23 individually controls a plurality of motors 60. For example, the motor control unit 23 executes the first turning control when it is determined that the driver desires a rapid turning and the vehicle C is turned. As described above, the motor control unit 23 can turn the vehicle C in a state where the left front wheel 50FL and the right front wheel 50FR (see FIG. 1A) are steered in the turning direction. ..

Specifically, the motor control unit 23 applies the first negative torque D1 to the inner wheels of the left and right drive wheels 50, which are inside when the vehicle turns, when the vehicle C is turned. In addition, the motor 60 of the inner ring is controlled. The first negative torque D1 is calculated by the following equation (1).
1st negative torque = load on inner ring x coefficient of dynamic friction of road surface + moment of inertia of tire
... Equation (1)

As a result, the inner ring is in the slip state, then shifts to the grip state and the rotation is stopped, so that the vehicle C can turn with the inner ring as the fulcrum B (see FIG. 1B). Therefore, in the present embodiment, the turning radius of the vehicle C can be reduced, and thus the turning performance of the vehicle C can be improved.

Further, the motor control unit 23 controls the motor 60 so that the first negative torque D1 is applied to the inner ring at once within a relatively short predetermined time range. That is, if the first negative torque D1 is applied over a long period of time exceeding the predetermined time range, the vehicle C will decelerate, but by applying the first negative torque D1 within the predetermined time range, the inner ring is immediately applied. It can be in a slip state.

Further, the motor control unit 23 can control the motor 60 so as to apply the first negative torque D1 to the inner ring and then apply the second negative torque D2 (see FIG. 1B) to the inner ring. The second negative torque D2 is smaller than the first negative torque D1 and is set to a value capable of continuing the state in which the inner ring is gripped on the road surface. Specifically, since the inner ring is subjected to a force pulled from the vehicle C or the like that is turned by the drive of the drive wheel 50 other than the inner ring, the second negative torque D2 is set to a value that can counter the applied force. For example, the second negative torque D2 is set based on the moment of inertia of the vehicle C and the like.

In this way, by applying the second negative torque D2, the inner ring can continue to be gripped on the road surface, that is, it can maintain the stopped state. Therefore, the state in which the inner ring functions as the fulcrum B can be maintained, and thus the turning of the vehicle C can be performed more reliably with the inner ring as the fulcrum B, and as a result, the turning performance of the vehicle C can be improved. It can be improved further.

Further, the switching from the application of the first negative torque D1 to the application of the second negative torque D2 may be performed, for example, at the timing when it is determined (estimated) that a slip state has occurred in the inner ring.

For example, the motor control unit 23 can determine whether or not a slip state has occurred in the inner ring based on the detected rotation speed of the drive wheel 50 after applying the first negative torque D1 to the inner ring. .. Specifically, the motor control unit 23 calculates the rotation speed acceleration based on the detected rotation speed of the drive wheel 50, and the rotation speed acceleration is equal to or less than a predetermined rotation speed acceleration indicating the occurrence of a slip state (rotation speed). When the deceleration becomes large), it can be determined that a slip state has occurred in the inner ring.

Then, when the motor control unit 23 determines that a slip state has occurred in the inner ring, the motor control unit 23 switches from the application of the first negative torque D1 to the application of the second negative torque D2. As a result, the motor control unit 23 can switch from the application of the first negative torque D1 to the application of the second negative torque D2 at an appropriate timing when the slip state occurs in the inner ring. The timing of switching described above is merely an example and is not limited.

Further, when a negative torque is applied to the inner ring, the motor control unit 23 can control the motor 60 of the outer ring so as to apply a positive torque E1 (see FIG. B) to the outer ring which is the outer side when the vehicle turns. For example, the positive torque E1 is set according to the required torque amount required for the vehicle C. The required torque amount is set according to the operation amount of the accelerator pedal (not shown).

Specifically, the motor control unit 23 controls the motor 60 of the outer ring so as to increase the positive torque E1 applied to the outer ring. Specifically, the motor control unit 23 controls the motor 60 of the outer ring so that the total amount of torque applied to all the drive wheels 50 is the required torque amount required for the vehicle C.

More specifically, the motor control unit 23 applies a positive torque E1 to the outer ring by adding the same torque amount as the absolute value of the negative torque applied to the inner ring to the torque amount previously applied to the outer ring as a positive torque. As a result, when a negative torque (for example, the first negative torque D1) is applied to the inner ring, it is possible to suppress a decrease in the drive torque of the vehicle C as a whole.

Further, the motor control unit 23 executes the first turning control when the speed of the vehicle C is less than a predetermined speed (first speed) and the vehicle C is traveling at a low speed. The inner ring motor 60 is controlled so as to apply the negative torque of 1. As a result, for example, since the first turning control is performed during low-speed driving, it is possible to reliably prevent the occurrence of vehicle spin or the like that may occur when making a sharp turn during high-speed driving. It becomes.

Here, with reference to FIGS. 3A and 3B, the turning of the vehicle C before and after the execution of the first turning control described above will be described in detail. FIG. 3A is a diagram showing the vehicle C before the execution of the first turning control, and FIG. 3B is a diagram showing the vehicle C after the execution.

In FIGS. 3A and 3B, the vector of the front wheels such as the left front wheel 50FL and the right front wheel 50FR is indicated by "vector Hf", and the vector of the rear wheels such as the left rear wheel 50RL and the right rear wheel 50RR is indicated by "vector Hrx, Hr". ing. Then, the vector of the moving direction of the vehicle C, which is a combination of the vector of the front wheels and the vector of the rear wheels, is indicated by "vectors Hcx, Hc". Further, in FIGS. 3A and 3B, "x" is added to the end of the sign of the vector before execution of the vector changed by the execution of the first turning control. Further, in FIG. 3B, the vector Hcx in the moving direction before execution is shown by a broken line in order to facilitate understanding by comparison.

As described above, when the first turning control (motor control) in which the first negative torque D1 is applied to the inner ring (right rear wheel 50RR in the example of FIG. 3B) is executed, the inner ring slips and then grips. Since it is in a state, the rotation is stopped. In the inner ring, the friction coefficient changes from the dynamic friction coefficient to the static friction coefficient, so that the frictional force acting on the inner ring increases. As a result, the vehicle C is turned with the inner wheel (right rear wheel 50RR) as the fulcrum B, and as shown in FIG. 3B, the vector Hr of the rear wheels transitions to the inside of the turn. Along with the transition of the vector Hr of the rear wheels, the vector Hc in the moving direction after the execution of the first turning control also shifts to the inside of the turning, and the turning performance of the vehicle C is improved.

Returning to the description of FIG. 2, the motor control unit 23 applies the above-mentioned first negative torque to the inner ring, for example, when the vehicle C turns while the vehicle C is not traveling at low speed or is stopped. The motor control to be performed, that is, the motor control different from the first turning control may be executed.

For example, the motor control unit 23 may prohibit the execution of the first turning control when the speed of the vehicle C is equal to or higher than the predetermined speed (first speed). Specifically, the first negative torque is applied to the inner ring. The applied motor control may be prohibited.

As a result, the turning of the vehicle C can be stabilized. That is, if the first negative torque is applied to the inner ring when the speed of the vehicle C is equal to or higher than a predetermined speed and the vehicle is not traveling at a low speed, the behavior of the vehicle C during turning tends to be unstable. Therefore, as described above, the turning of the vehicle C can be stabilized by prohibiting the motor control (first turning control) that applies the first negative torque. The motor control unit 23 may prohibit the first turning control for applying the first negative torque to the inner ring even when the steering operation amount is less than the predetermined maximum amount.

Further, when the speed of the vehicle is equal to or higher than a predetermined speed and the first turning control is not prohibited, the motor control unit 23 may execute the normal motor control or turn, which is different from the first turning control. Motor control of the time may be performed. Hereinafter, the motor control at the time of turning may be described as "second turning control".

As the second turning control, the motor control unit 23 controls the motor 60 so that, for example, a negative torque is applied to the inner ring within a range in which a slip state does not occur. As a result, the motor control unit 23 can prevent the inner ring of the vehicle C from being slipped during turning and the behavior from becoming unstable.

The motor control unit 23 may apply a positive torque corresponding to the negative torque applied to the inner ring to the outer ring when executing the second turning control.

Next, turning with the vehicle C stopped will be described. When the vehicle C turns while the vehicle is stopped, the inner ring is already stopped. Therefore, when the speed of the vehicle C is equal to or lower than the second speed, the motor control unit 23 prohibits the first turning control that applies the first negative torque to the inner ring, and has a turning radius smaller than that of the first turning control. A third turning control that enables turning may be performed. The above-mentioned second speed is a speed lower than the first speed, and is set to, for example, 0 speed or almost 0 speed. Therefore, when the speed of the vehicle C is equal to or lower than the second speed, it means that the vehicle C is in a stopped state or is almost stopped.

Specifically, the third turning control will be described specifically. When the speed of the vehicle C is equal to or lower than the second speed, for example, the motor control unit 23 steers each of the four drive wheels 50 in the desired turning direction, and in that state. Drive the four drive wheels in the direction you want to turn. As a result, the vehicle C is turned around the center point of the vehicle, and the turning performance of the vehicle C can be further improved.

As the third turning control, the inner ring is stopped by using the mechanical brake without applying the negative torque to the inner ring in the first turning control, and the inner ring is used as the fulcrum B of the vehicle C. Control to make a turn may be performed.

Further, in the above-mentioned third turning control, the turning amount of the vehicle C with respect to the steering operation amount is larger than that in the normal turning control such as the second turning control. Therefore, unless the driver is made aware that the third turning control is performed, the driver may feel uncomfortable due to the large turning amount. Further, since the third turning control is basically performed in a stopped state, it is not necessary to immediately execute the turning control.

Therefore, the motor control unit 23 may execute the third turning control when it receives a special execution instruction instructing the execution of the third turning control different from the normal steering steering from the driver or the like. Good. Specifically, for example, a predetermined operation button provided in the vehicle interior is operated by the driver, or there is an utterance of the driver instructing the execution (for example, "turn right at this place"). If so, the motor control unit 23 may receive the execution instruction and execute the third turning control.

As a result, since the driver recognizes that the third turning control is performed, it is possible to make it difficult for the driver to feel a sense of discomfort due to the large turning amount due to the third turning control. The motor control unit 23 executes the first turning control when it receives a special execution instruction instructing the execution of the first turning control to which the first negative torque is applied, not limited to the third turning control. You may do so.

Further, the motor control unit 23 may execute the third turning control after a predetermined time set in advance has elapsed after receiving the execution instruction. The predetermined time is set to a value that allows the driver to prepare for the third turning control with a margin, but is not limited to this. That is, it can be said that the predetermined time is a predetermined waiting time.

As a result, the driver can perform the third turning control with a large turning amount with a margin.

The notification unit 24 can notify the occupant of information regarding the motor control. For example. When executing the first turning control or the third turning control that makes a steeper turn than the normal turning control such as the second turning control, the notification unit 24 executes a predetermined notification control to the occupants of the vehicle. The predetermined notification control is, for example, a control for notifying the occupants of the vehicle that the predetermined motor control such as the first turning control and the third turning control is executed. It should be noted that such notification is performed by visual notification such as sound (voice) notification or lighting of an indicator lamp, but the notification method is not limited to these.

This makes it possible for the driver to recognize that a predetermined motor control such as the first turning control and the third turning control is performed, and makes it difficult for the driver to feel a sense of discomfort due to the predetermined motor control. be able to. In particular, when the vehicle C is in the traveling state, it is possible to prevent the traveling state of the vehicle C from becoming unstable due to the turning control that the driver does not recognize.

Next, a processing procedure executed by the motor control device 10 according to the embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing an example of a processing procedure executed by the motor control device 10.

As shown in FIG. 4, the control unit 20 of the motor control device 10 determines whether or not the yaw rate of the vehicle C is equal to or higher than a predetermined yaw rate (step S10). The predetermined yaw rate is set to a value that can be determined, for example, that the vehicle C is skidding. That is, in step S10, it is determined whether or not the vehicle C is in a skid state.

When it is determined that the yaw rate of the vehicle C is not equal to or higher than the predetermined yaw rate (steps S10, No), the control unit 20 determines whether or not the steering operation amount is equal to or more than the predetermined operation amount (for example, the predetermined maximum amount) (step S10, No). Step S11).

When it is determined that the steering operation amount is equal to or more than the predetermined operation amount (step S11, Yes), the control unit 20 determines whether or not the speed of the vehicle C is less than the first speed (predetermined speed) (step). S12). That is, steps S11 and S12 are processes for determining whether or not the driver desires a rapid turn while the vehicle C is in a low-speed running state or a stopped state.

When it is determined that the speed of the vehicle C is less than the first speed (step S12, Yes), the control unit 20 determines whether or not the speed of the vehicle C is lower than the first speed and is equal to or less than the second speed. (Step S13). That is, step S13 is a process of determining whether or not the vehicle C is in the stopped state.

When the control unit 20 determines that the speed of the vehicle C is not equal to or lower than the second speed (steps S13, No), that is, when the vehicle C is not in a stopped state but in a low-speed running state, the control unit 20 has a first inner ring. The first turning control, which controls the motor 60 so as to apply a negative torque, is executed (step S14). Subsequently, the control unit 20 controls the motor 60 of the outer ring so as to apply a positive torque to the outer ring, specifically, to increase the positive torque applied to the outer ring (step S15).

Next, the control unit 20 determines whether or not a slip state has occurred in the inner ring (step S16). Specifically, in step S16, the control unit 20 determines whether or not the rotation speed acceleration of the motor 60 of the inner ring is equal to or less than the predetermined rotation speed acceleration.

Next, when it is determined that a slip state has occurred in the inner ring (step S16, Yes), the control unit 20 executes a first turning control that controls the motor 60 so as to apply a second negative torque to the inner ring. (Step S17). That is, the control unit 20 switches from the application of the first negative torque D1 to the application of the second negative torque D2.

On the other hand, the control unit 20 determines that the slip state has not occurred in the inner ring (steps S16, No), that is, the rotation speed acceleration of the motor 60 of the inner ring is not equal to or less than the predetermined rotation speed acceleration. If so, the process of step S17 is skipped.

When it is determined that the yaw rate of the vehicle C is equal to or higher than the predetermined yaw rate (steps S10, Yes), the control unit 20 executes the second turning control (step S18). Further, the control unit 20 determines that the steering operation amount is not equal to or more than the predetermined operation amount (steps S11, No), or that the speed of the vehicle C is not less than the first speed (step S12). , No), that is, if the driver does not want a rapid turn, the process proceeds to step S18 and the second turn control is executed. In other words, when the speed of the vehicle C is equal to or higher than the first speed, the control unit 20 prohibits the execution of the first turning control and executes the second turning control.

When the control unit 20 determines that the speed of the vehicle C is equal to or lower than the second speed (steps S13, Yes), that is, when it is determined that the vehicle C is in a stopped state, has the preset predetermined time elapsed? Whether or not it is determined (step S19). When it is determined that the predetermined time has not elapsed (steps S19, No), the control unit 20 repeats the process of step S19.

When it is determined that the predetermined time has elapsed (step S19, Yes), the control unit 20 performs the third turning control (step S20).

As described above, the motor control device 10 according to the embodiment includes the motor control unit 23. The motor control unit 23 individually controls the rotary drive motors 60 attached to the left and right drive wheels 50 of the vehicle C, respectively. Further, when the vehicle C is turned, the motor control unit 23 controls the motor 60 of the inner ring so as to apply the first negative torque to the inner ring which is the inner ring of the left and right drive wheels 50 when the vehicle is turned, and the inner ring. After applying the first negative torque to the inner ring, the first turning control is executed, which controls the motor 60 so as to apply a second negative torque smaller than the first negative torque to the inner ring. Thereby, the turning performance of the vehicle C can be improved.

In the above-described embodiment, the motor control device 10 executes the first turning control and the third turning control when the driver desires a rapid turning and turns the vehicle C. For example, the first turning control may be executed when a normal turning other than a rapid turning is performed.

Further, in order to enhance safety during rapid turning, the positive torque applied to the outer ring in the first turning control may be as follows. For example, the positive torque applied to the outer ring in the first turning control is a torque amount smaller than the absolute value of the negative torque applied to the inner ring, or a torque amount smaller than the positive torque applied to the outer ring in the second turning control. You may.

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the spirit or scope of the general concept of the invention as defined by the appended claims and their equivalents.

10 Motor control device 20 Control unit 21 Detection unit 22 Swivel judgment unit 23 Motor control unit 24 Notification unit 50 Drive wheel 60 Motor

Claims (11)

Equipped with a motor control unit that individually controls the rotary drive motors attached to the left and right drive wheels of the vehicle.
The motor control unit
When turning the vehicle, the motor of the inner ring is controlled so as to apply a first negative torque to the inner ring which is inside when the vehicle turns among the left and right drive wheels, and the first negative torque is applied to the inner ring. A motor control device, characterized in that a first turning control is executed, which controls the motor so as to apply a second negative torque smaller than the first negative torque to the inner ring. The motor control unit
The first aspect of claim 1, wherein the second negative torque is applied to the inner ring when it is determined that a slip state has occurred in the inner ring after the first negative torque is applied to the inner ring. Motor control device. The motor control unit
The claim is characterized in that when a negative torque is applied to the inner ring, the motor of the outer ring is controlled so as to increase the positive torque applied to the outer ring which is the outer side of the left and right drive wheels when the vehicle turns. The motor control device according to 1 or 2. The motor control unit
The motor control device according to claim 3, wherein the motor of the outer ring is controlled so that the total amount of torque applied to all the drive wheels is the required torque amount required for the vehicle. .. The motor control unit
The motor control device according to any one of claims 1 to 4, wherein when the speed of the vehicle is the first speed or higher, the execution of the first turning control is prohibited. The motor control unit
A claim characterized in that when the speed of the vehicle is equal to or higher than the first speed, a second turning control is executed, which controls the motor so as to apply a negative torque to the inner ring within a range in which a slip state does not occur. Item 4. The motor control device according to any one of Items 1 to 5. The motor control unit
Claims 1 to 1, characterized in that, when the speed of the vehicle is lower than the first speed and is equal to or lower than the second speed, the third turning control that enables turning with a turning radius smaller than the first turning control is executed. 6. The motor control device according to any one of 6. The motor control unit
The motor control device according to claim 7, wherein the third turning control is executed when an execution instruction for instructing the execution of the third turning control, which is different from the normal steering steering, is received. The motor control unit
The motor control device according to claim 8, wherein the third turning control is executed after a predetermined time set in advance has elapsed after receiving the execution instruction. The invention according to any one of claims 7 to 9, wherein when the first turning control or the third turning control is executed, a notification unit for executing a predetermined notification control to the occupant of the vehicle is provided. Motor control device. Includes a motor control process that individually controls the rotary drive motors attached to the left and right drive wheels of the vehicle.
The motor control process is
When turning the vehicle, the motor of the inner ring is controlled so as to apply a first negative torque to the inner ring which is inside when the vehicle turns among the left and right drive wheels, and the first negative torque is applied to the inner ring. A motor control method, characterized in that a first turning control is executed, in which the motor is controlled so as to apply a second negative torque smaller than the first negative torque to the inner ring.

Images