Vehicle control device, vehicle control system, and program

Abstract

To solve the problem that dispersion occurs in control of motors corresponding to respective four wheels.SOLUTION: The vehicle control device 10 includes a controller that controls a motor provided in each of a plurality of wheels of the vehicle 1. The controller transmits, to the inverter corresponding to each of the motors, common data including an ID corresponding to a reference value of the control value and information on distribution of the control value to the plurality of wheels.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device, a vehicle control system, and a program. [Background technology]

[0002] Vehicles equipped with in-wheel motors have been under development. Vehicles equipped with in-wheel motors do not require drive shafts and can rotate and steer all four wheels independently.

[0003] For example, Patent Document 1 describes a configuration in which one inverter is installed for each of four in-wheel motors to independently control the four wheels. A host VCU (Vehicle Control Unit) sends target torque and other information to each inverter via CAN (Controller Area Network) communication. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-196199 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional technology has a problem in that there is variation in the control of the motors corresponding to each of the four wheels.

[0006] For example, if commands are sent to four inverters one by one via CAN communication, the timing at which the commands reach each inverter will differ, resulting in variations in the control of each motor.

[0007] The present invention has been made in view of the above, and has an object to reduce the variation in control of the motors corresponding to each of the four wheels. [Means for solving the problem]

[0008] A vehicle control device according to the present invention includes a controller that controls a motor provided for each of a plurality of wheels of a vehicle. The controller transmits common data to the inverters corresponding to each of the motors, the common data including an ID corresponding to a reference value of a control value and information regarding distribution of the control value to the plurality of wheels. [Effects of the Invention]

[0009] According to the present invention, when controlling four wheels independently, control signals can be sent to the four inverters simultaneously, rather than being sent individually and sequentially to the four inverters, thereby reducing the variation in control of the motors corresponding to each of the four wheels. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a vehicle according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a VCU according to the embodiment. [Figure 3] FIG. 3 is a functional block diagram of the VCU controller. [Figure 4] FIG. 4 is a flowchart showing the flow of processing by the controller of the VCU. [Figure 5] FIG. 5 is a diagram illustrating the structure of a frame. [Figure 6] FIG. 6 is a diagram illustrating the structure of a frame. [Figure 7] FIG. 7 is a diagram illustrating an example of the configuration of the wheel control device according to the embodiment. [Figure 8] FIG. 8 is a functional block diagram of the controller of the wheel control device. [Figure 9] FIG. 9 is a flowchart showing the flow of processing by the controller of the wheel control device. [Figure 10] FIG. 10 is a diagram illustrating an example of a frame. [Figure 11] FIG. 11 is a diagram illustrating an example of a frame. [Figure 12] FIG. 12 is a diagram illustrating an example of a frame. [Figure 13] FIG. 13 is a diagram illustrating the control of the wheels. [Figure 14] FIG. 14 is a diagram illustrating an example of a frame. [Figure 15] FIG. 15 is a diagram illustrating the control of the wheels. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of a vehicle control device, a vehicle control system, and a program disclosed herein will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below. Note that the VCU in the embodiments is an example of a vehicle control device.

[0012] The configuration of a vehicle according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of a vehicle according to an embodiment. A vehicle control system is the whole or a part of the vehicle.

[0013] As shown in FIG. 1, a vehicle 1 includes a VCU 10, a wheel control device 20LF, a wheel 30LF, a wheel control device 20RF, a wheel 30RF, a wheel control device 20LR, a wheel 30LR, a wheel control device 20RR, and a wheel 30RR.

[0014] The alphabetic characters "LF," "RF," "LR," and "RR" included in the reference numerals correspond to the left front wheel, right front wheel, left rear wheel, and right rear wheel, respectively. For example, the wheel control device 20RF controls the right front wheel 30RF. When there is no need to distinguish between the corresponding wheels, the reference numerals may be written without the alphabetic characters. For example, the wheel control devices 20LF, 20RF, 20LR, and 20RR may be written as the wheel control device 20 without distinction. Note that the wheel in this embodiment includes a wheel equipped with an in-wheel motor and a tire.

[0015] In addition, the positive direction of the x-axis in FIG. 1 is the forward direction, and the negative direction of the x-axis is the backward direction. The positive direction of the y-axis is the right direction, and the negative direction of the y-axis is the left direction. The positive direction of the z-axis (toward the viewer in the drawing) is vertically upward, and the negative direction of the z-axis (toward the viewer in the drawing) is vertically downward. The turning and rotation directions will be explained based on the view of vehicle 1 as viewed from above, i.e., vertically downward. For example, a right turn means that vehicle 1 turns to the right.

[0016] The wheel control device 20 controls the wheels 30 in response to the signals received from the VCU 10. The VCU 10 simultaneously transmits signals to the wheel control devices 20LF, 20RF, 20LR, and 20RR. For example, the signals are transmitted as CAN communication frames.

[0017] The wheel control device 20 analyzes the received frame and acquires a control value (for example, a torque command value) corresponding to itself. The wheel control device 20 controls the corresponding wheel 30 according to the acquired control value. Specifically, the wheel control device 20 controls an inverter for driving a motor provided in the wheel 30. In the following description, it is assumed that the wheel control device 20 acquires a torque command value for each wheel as a control value.

[0018] The configuration of a VCU according to an embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the configuration of a VCU according to an embodiment. As shown in Fig. 2, a VCU 10 includes an interface 11, a controller 12, and a memory 13.

[0019] The interface 11 inputs and outputs data between the VCU 10 and other devices. For example, the interface 11 is a port compatible with USB (Universal Serial Bus), Ethernet (registered trademark), CAN (Controller Area Network), etc.

[0020] The controller 12 reads and executes a program stored in the memory 13. The controller 12 is a central processing unit (CPU), a digital signal processor (DSP), a field programmable gate array (FPGA), a graphics processing unit (GPU), a system on a chip (SoC), or the like.

[0021] The controller 12 may be a single processor, a multiprocessor configuration, or a multicore configuration having multiple cores in a single chip connected via a single socket.

[0022] The controller 12 executes a program to realize each processing unit shown in Fig. 2. Fig. 3 is a functional block diagram of the controller of the VCU. As shown in Fig. 3, the controller 12 includes a calculation unit 121 and a transmission control unit 122.

[0023] The calculation unit 121 calculates a value to be written into the frame based on the torque command value of each wheel. The torque command value may be determined by the driver's operation or by processing of the ECU or the like.

[0024] The transmission control unit 122 appropriately adds a header or the like to the value calculated by the calculation unit 121 and transmits it as a frame. At this time, the transmission control unit 122 transmits the same frame to each of the wheel control devices 20 (for example, broadcast).

[0025] Here, a method for transmitting the torque command value for each wheel in this embodiment will be described. In this embodiment, the controller 12 of the VCU 10 transmits the total torque, which is the sum of the torque command values ​​for each wheel, and the torque distribution ratio for each wheel as frame information to the wheel control device 20. Each wheel control device 20 calculates its own torque command value based on the total torque and torque distribution ratio from the received frame information. Therefore, in this embodiment, the total torque for each wheel is expressed by a frame ID common to the wheel control device 20. This allows each wheel control device 20 to identify the total torque from the frame ID when it receives a frame. However, if the total torque and frame ID are associated one-to-one, a large number of IDs would be required. Therefore, in this embodiment, the frame ID is previously associated with a reference value of the total torque (for example, 0 Nm, 20 Nm, etc., in 20 Nm increments), and the amount of total torque that falls short of the reference value is expressed as a torque offset value. For example, if the total torque is 8 Nm, the reference value is set to 0 Nm, and the ID "0x100" corresponding to the reference value is selected. The torque offset value is then set to 8 Nm, which is the difference from the reference value. If the total torque is 22 Nm, the reference value is set to 20 Nm, and the ID "0x120" corresponding to the reference value is selected. The torque offset value is then set to 2 Nm, which is the difference from the reference value. The reference value may be set in 10 Nm increments, such as 0 Nm, 10 Nm, or 20 Nm, or may be set to any other increment.

[0026] In this way, the controller 12 simultaneously transmits information on the total torque of the four wheels using a common frame ID corresponding to a reference value and a torque offset value to each wheel control device 20. If there are a large number of frame IDs, the total torque value may be set as a reference value for each, and there may be a one-to-one correspondence between the total torque and the frame ID. In this case, the torque offset value is not necessary.

[0027] The torque distribution ratio is expressed as the front / rear torque distribution, which indicates the proportion of front wheel torque in the total torque, the front wheel left / right torque distribution, which indicates the proportion of left front wheel torque in the front wheel torque, and the rear wheel left / right torque distribution, which indicates the proportion of left rear wheel torque in the rear wheel torque.

[0028] For example, if the torque command values ​​for the left front wheel, right front wheel, left rear wheel, and right rear wheel are A, B, C, and D, respectively, the controller 12 calculates the front / rear torque distribution as (A+B) / (A+B+C+D). The controller 12 also calculates the front wheel torque left / right distribution as A / (A+B). The controller 12 also calculates the rear wheel torque left / right distribution as C / (C+D).

[0029] As a result, when the wheel control device 20LF for the left front wheel receives frame information, it calculates the total torque from the frame ID and torque offset value, and calculates its own torque command value using the formula: total torque x front / rear torque distribution x front wheel left / right torque distribution.

[0030] The wheel control device 20RF for the right front wheel calculates its own torque command value using the formula: total torque x front / rear torque distribution x (1 - front wheel torque left / right distribution), since the front wheel torque left / right distribution is the proportion of the front wheel torque accounted for by the left front wheel.

[0031] The wheel control device 20LR for the left rear wheel calculates its own torque command value using the formula total torque x (1 - torque front / rear distribution) x rear wheel torque left / right distribution, since the torque front / rear distribution is the proportion of the total torque that the front wheels account for.

[0032] The wheel control device 20RR for the right rear wheel calculates its own torque command value using the formula: total torque × (1 - front / rear torque distribution) × (1 - rear wheel torque distribution), since the front / rear torque distribution is the proportion of the front wheel in the total torque, and the rear wheel left / right torque distribution is the proportion of the left rear wheel in the rear wheel torque.

[0033] In this way, the controller 12 of the VCU 10 transmits the frame ID corresponding to the reference value, the torque offset value, the front / rear torque distribution, the left / right front wheel torque distribution, and the left / right rear wheel torque distribution. Each wheel control device 20 simultaneously receives the frame information and calculates its own torque command value. Therefore, each wheel control device 20 can simultaneously receive the torque command value without any time lag.

[0034] The front / rear torque distribution may indicate the proportion of rear wheel torque in the total torque. The front wheel left / right torque distribution may indicate the proportion of right front wheel torque in the total front wheel torque. The rear wheel left / right torque distribution may indicate the proportion of right rear wheel torque in the total rear wheel torque.

[0035] The processing flow of the controller 12 will be described using Figure 4. Figure 4 is a flowchart showing the processing flow of the VCU controller. However, here, it is assumed that the vehicle 1 moves forward, and all torque command values ​​are positive. Moving forward means accelerating forward, and includes deceleration while moving backward.

[0036] 4, first, the calculation unit 121 acquires the left front wheel torque, the right front wheel torque, the left rear wheel torque, and the right rear wheel torque (step S101). The calculation unit 121 can acquire each torque from another ECU or the like.

[0037] Next, the calculation unit 121 calculates the total torque of the four wheels, obtains a reference value from the total torque, and obtains a frame ID corresponding to the reference value (step S102). Next, the calculation unit 121 calculates the torque offset value as "four-wheel total torque-reference value" (step S103). Note that the value obtained by subtracting 100 from the numeric portion of the ID corresponds to the reference value.

[0038] Next, calculation unit 121 calculates the front / rear torque distribution as "(left front wheel torque + right front wheel torque) / total torque of four wheels" (step S104). In other words, the front / rear torque distribution indicates the proportion of front wheel torque in the total torque. For example, if the front / rear torque distribution is 60%, it indicates that the front wheel torque is 60% of the total torque and the rear wheel torque is 40% of the total torque. Furthermore, calculation unit 121 calculates the front wheel torque left / right distribution as "left front wheel torque / (left front wheel torque+right front wheel torque)" (step S105). That is, the front wheel torque left / right distribution indicates the proportion of left front wheel torque in the front wheel torque. For example, if the front wheel torque left / right distribution is 60%, this indicates that the left front wheel torque is 60% of the front wheel torque and the right front wheel torque is 40% of the front wheel torque. Furthermore, calculation unit 121 calculates the rear wheel torque left / right distribution as "left rear wheel torque / (left rear wheel torque+right rear wheel torque)" (step S106). That is, the rear wheel torque left / right distribution indicates the proportion of left rear wheel torque in the rear wheel torque. For example, if the rear wheel torque left / right distribution is 60%, this indicates that the left rear wheel torque is 60% of the rear wheel torque and the right rear wheel torque is 40% of the rear wheel torque.

[0039] The transmission control unit 122 places the torque offset value in the first byte, the front / rear torque distribution in the second byte, the front wheel left / right torque distribution in the third byte, and the rear wheel left / right torque distribution in the fourth byte, and transmits a frame with a frame ID and a header attached (step S107).

[0040] 5 and 6 are diagrams for explaining the structure of a frame. Byte 1, Byte 2, Byte 3, and Byte 4 shown in FIGS. 5 and 6 are the values ​​of the first byte, second byte, third byte, and fourth byte, respectively. Note that the torque offset value, front / rear torque distribution, front wheel left / right torque distribution, and rear wheel left / right torque distribution are not limited to one byte. The number of bytes can be determined according to the value each can take.

[0041] One byte can represent a decimal integer between 0 and 255. Therefore, the ratio of front / rear distribution, left / right distribution, etc. can be expressed in 1 byte at least from 0% to 100% in 1% increments.

[0042] The ID of the frame is the CAN ID. The ID may correspond to a reference value for calculating the torque offset value. For example, the ID "0x100" corresponds to the reference value "0 Nm." For example, the ID "0x120" corresponds to the reference value "20 Nm."

[0043] 2, the memory 13 is a storage medium such as an embedded multi-media card (eMMC), etc. The memory 13 functions as a read-only memory (ROM) or a random access memory (RAM).

[0044] The configuration of the wheel control device according to the embodiment will be described using Fig. 7. Fig. 7 is a diagram showing an example of the configuration of the wheel control device according to the embodiment. As shown in Fig. 7, the wheel control device 20 has an interface 21, a controller 22, a memory 23, and an inverter 24. The inverter 24 is connected to a motor 31 provided in a wheel 30. The motor 31 is an in-wheel motor.

[0045] The interface 21 inputs and outputs data between the wheel control device 20 and other devices. For example, the interface 21 is a port compatible with USB, Ethernet (registered trademark), CAN, or the like.

[0046] The controller 22 reads and executes a program stored in the memory 23. The controller 22 is a CPU, a DSP, an FPGA, a GPU, an SoC, or the like.

[0047] The controller 22 may be a single processor, a multiprocessor configuration, or a multicore configuration having multiple cores in a single chip connected via a single socket.

[0048] The controller 22 executes a program to realize each processing unit shown in Fig. 8. Fig. 8 is a functional block diagram of the controller of the wheel control device. As shown in Fig. 8, the controller 22 has an analysis unit 221 and an inverter control unit 222.

[0049] The analysis unit 221 analyzes the received frame and obtains a torque command value for controlling the corresponding wheel 30 .

[0050] The inverter control unit 222 controls the inverter 24 based on the torque command value acquired by the analysis unit 221. For example, the inverter control unit 222 transmits the torque command value to the inverter 24. The inverter 24 drives the motor 31 in accordance with the torque command value. The inverter control unit 222 controls the motor 31 indirectly via the inverter 24.

[0051] 7, the memory 23 is a storage medium such as an eMMC, etc. The memory 23 functions as a ROM or a RAM.

[0052] The processing flow of the controller 22 will be described with reference to Fig. 9. Fig. 9 is a flowchart showing the processing flow of the controller of the wheel control device. Here, it is assumed that the wheel control device 20 receives the frame transmitted by the processing described in Fig. 4.

[0053] As shown in Fig. 9, first, the analysis unit 221 receives a frame (step S201). Next, the analysis unit 221 acquires a reference value from the frame ID (step S202). For example, if the frame ID is "0x120", the analysis unit 221 acquires "20Nm" as the reference value. Next, the analysis unit 221 acquires the following value from the frame (step S203): 1st byte value: Torque offset value Second byte value: Torque distribution 3rd byte value: Front wheel torque distribution 4th byte value: Rear wheel torque distribution

[0054] Next, the analysis unit 221 calculates the four-wheel total torque as "reference value + torque offset value" (step S204). Thereafter, the analysis unit 221 performs processing according to the wheel corresponding to the wheel control device 20. It is assumed that the wheel corresponding to the wheel control device 20 is stored in advance in the memory 23.

[0055] If the wheel control device 20 corresponds to the left front wheel (step S205, Yes), the analysis unit 221 calculates the torque command value (left front wheel torque) as "four-wheel total torque × front / rear torque distribution × front wheel torque left / right distribution" (step S206). That is, the front / rear torque distribution acquired in step S203 indicates the proportion of front wheel torque in the four-wheel total torque, and the front wheel torque left / right distribution indicates the proportion of left front wheel torque in the front wheel torque. Therefore, the analysis unit 221 of the wheel control device 20 corresponding to the left front wheel can find the torque command value for itself by calculating four-wheel total torque × front / rear torque distribution × front wheel torque left / right distribution.

[0056] If the wheel control device 20 corresponds to the right front wheel (step S207, Yes), the analysis unit 221 calculates the torque command value (right front wheel torque) as "four wheel total torque × front / rear torque distribution × (1 - front wheel torque left / right distribution)" (step S208). That is, since the front wheel torque left / right distribution indicates the proportion of left front wheel torque in the front wheel torque, the proportion of right front wheel torque in the front wheel torque is obtained as (1 - front wheel torque left / right distribution). Therefore, the analysis unit 221 of the wheel control device 20 corresponding to the right front wheel can obtain the torque command value for itself by calculating four wheel total torque × front / rear torque distribution × (1 - front wheel torque left / right distribution).

[0057] If the wheel control device 20 corresponds to the left rear wheel (step S209, Yes), the analysis unit 221 calculates the torque command value (left rear wheel torque) as "four wheel total torque × (1 - torque front / rear distribution) × rear wheel torque left / right distribution" (step S210). That is, since the torque front / rear distribution indicates the proportion of front wheel torque in the four wheel total torque, the proportion of rear wheel torque in the four wheel total torque is obtained as (1 - torque front / rear distribution). Furthermore, the rear wheel torque left / right distribution indicates the proportion of left rear wheel torque in the rear wheel torque. Therefore, the analysis unit 221 of the wheel control device 20 corresponding to the left rear wheel can obtain a torque command value for itself by calculating the four wheel total torque × (1 - torque front / rear distribution) × rear wheel torque left / right distribution.

[0058] If the wheel control device 20 corresponds to the right rear wheel (step S211, Yes), the analysis unit 221 calculates the torque command value (right rear wheel torque) as "four wheel total torque × (1 - torque front / rear distribution) × (1 - rear wheel torque left / right distribution)" (step S212). That is, since the rear wheel torque left / right distribution indicates the proportion of left rear wheel torque in rear wheel torque, the proportion of right rear wheel torque in rear wheel torque is obtained as (1 - rear wheel torque left / right distribution). Therefore, the analysis unit 221 of the wheel control device 20 corresponding to the right rear wheel can obtain the torque command value for itself by calculating four wheel total torque × (1 - torque front / rear distribution) × (1 - rear wheel torque left / right distribution).

[0059] The inverter control unit 222 transfers the torque command value to the inverter 24 (step S213).

[0060] In this way, each wheel control device 20 simultaneously receives frames from the VCU 10 and calculates the torque command value for itself, so that the torque command value for each wheel control device 20 can be calculated at the same time, preventing variations in the control of each motor.

[0061] It is assumed that the wheel control device 20 receives the frame shown in Fig. 10. Fig. 10 is a diagram showing an example of the frame, but the header is omitted in Fig. 10.

[0062] When the calculation unit 121 acquires "1 Nm," "3 Nm," "2 Nm," and "4 Nm" as the left front wheel torque, right front wheel torque, left rear wheel torque, and right rear wheel torque, respectively, a frame like that shown in FIG. 10 is transmitted. Specifically, since the total torque is 1 + 3 + 2 + 4 = 10.0 Nm, the calculation unit 121 determines 0 Nm as the reference value and the corresponding frame ID "0x100." The calculation unit 121 calculates an offset value of 10.0 Nm using the formula "total torque - reference value." This becomes the data in Byte 1.

[0063] The calculation unit 121 calculates the front / rear torque distribution as 40% using the formula "(left front wheel torque + right front wheel torque) / total torque of four wheels." This becomes the data of Byte 2.

[0064] The calculation unit 121 calculates the front wheel torque left / right distribution as 25% using the formula "left front wheel torque / (left front wheel torque+right front wheel torque)". This becomes the data of Byte3.

[0065] The calculation unit 121 calculates the rear wheel torque left / right distribution as 33% using the formula "left rear wheel torque / (left rear wheel torque+right rear wheel torque)". This becomes Byte 4 data.

[0066] Based on the frame of Fig. 10, the analysis unit 221 of each wheel control device 20 can calculate the left front wheel torque, right front wheel torque, left rear wheel torque, and right rear wheel torque as "1 Nm," "3 Nm," "2 Nm," and "4 Nm," respectively, using the calculation formulas explained in Fig. 9. However, the analysis unit 221 only needs to calculate the torque command value of the wheel corresponding to the wheel control device 20.

[0067] [When vehicle 1 is moving other than forward] In addition to moving forward, the vehicle 1 can also move backward, turn on the spot, and move laterally. The forward, backward, turn on the spot, and lateral movement of the vehicle 1 are controlled by a mode and a torque command value. The VCU 10 transmits information indicating the mode (forward, backward, turn on the spot, or lateral movement) to each of the wheel control devices 20 in advance, and then transmits a torque command value. The wheel control device 20 stores information indicating the current mode in the memory 23.

[0068] The processing described using Figures 4 and 9 is processing in forward mode. Forward movement means acceleration forward, and includes deceleration during reverse movement. In forward mode, all torque command values ​​are positive. A positive torque command value means that the motor 31 rotates so that the wheels 30 rotate in the direction in which the vehicle 1 moves forward.

[0069] In this way, the controller 12 transmits common data including an ID corresponding to the reference value of the torque command value and information regarding distribution of the torque command value to the plurality of wheels to the inverters 24 corresponding to each of the motors 31. The data is transmitted as a frame.

[0070] In this case, each inverter 24 can simultaneously receive a torque command value, thereby reducing variations in the control of the motors 31 corresponding to each of the four wheels.

[0071] For example, when one frame is transmitted in 8 ms, according to this embodiment, transmission of torque command values ​​to the four inverters 24 is completed in 8 ms. Moreover, the four inverters 24 obtain the torque command values ​​at the same timing.

[0072] With conventional technology, to complete the transmission of torque command values ​​in the same amount of time, it is necessary to transmit frames to the four inverters sequentially at 2 ms intervals. This poses the problem of increased CAN communication traffic. Furthermore, the timing at which the four inverters obtain the torque command values ​​is offset by 2 ms.

[0073] In this way, this embodiment has the effect of reducing the amount of communication traffic and enabling each inverter to receive command values ​​at the same time. Furthermore, the reduction in traffic speeds up the detection of an interruption in CAN communication and the recovery from the interruption.

[0074] Furthermore, the controller 12 transmits data including a correction value for the reference value, that is, an offset value, which allows the total torque to be expressed with fewer types of IDs, thereby reducing the number of IDs.

[0075] The controller 12 transmits data including the distribution ratio of the torque command value between the front wheels and the rear wheels, the distribution ratio of the torque command value between the right front wheel and the left front wheel, and the distribution ratio of the torque command value between the right rear wheel and the left rear wheel. In this way, control is achieved without transmitting information for all four wheels, thereby reducing the amount of data transmission.

[0076] 10, the controller 12 transmits data including the distribution ratio of the torque command value to either the front wheels or the rear wheels, the distribution ratio of the torque command value to either the right front wheel or the left front wheel, and the distribution ratio of the torque command value to either the right rear wheel or the left rear wheel. For example, the distribution ratio of the rear wheels can be obtained by subtracting the distribution ratio of the front wheels from 1. Therefore, by transmitting only one of the paired distribution ratios, the amount of data transmission can be reduced.

[0077] Specifically, as shown in Fig. 5 etc., the controller 12 transmits data including a predetermined byte (e.g., 1 byte) value indicating a correction value relative to a reference value, a predetermined byte value indicating a distribution ratio of the torque command value between the front wheels and the rear wheels, a predetermined byte value indicating a distribution ratio of the torque command value between the right front wheel and the left front wheel, and a predetermined byte value indicating a distribution ratio of the torque command value between the right rear wheel and the left rear wheel. In this way, the controller 12 can achieve efficient communication by storing each piece of information in a predetermined byte. In particular, by storing each piece of information in one byte, all information can be stored in, for example, 8 bytes, which is the length of the data portion of a typical CAN (Controller Area Network) frame, and the memory area in which each piece of information is stored can be limited to an area (1 byte) corresponding to one address.

[0078] (reverse mode) In the reverse mode, the VCU 10 transmits a frame as shown in Fig. 11 to the wheel control unit 20. Fig. 11 is a diagram showing an example of the frame.

[0079] 11, in the reverse mode, the front / rear torque distribution (Byte2) of the frame is negative. Note that the wheel control device 20 may determine whether the mode is the forward mode or the reverse mode depending on whether the front / rear torque distribution is positive or negative.

[0080] In the forward drive mode, the left front wheel torque, right front wheel torque, left rear wheel torque, and right rear wheel torque are all positive values ​​in step S101 of Fig. 4. On the other hand, in the reverse drive mode, the left front wheel torque, right front wheel torque, left rear wheel torque, and right rear wheel torque are all negative values ​​in step S101 of Fig. 4.

[0081] In the reverse mode, the calculation of the torque offset value in S103 of Fig. 4 is replaced with "-4-wheel total torque-reference value." Also, in the reverse mode, "1-front / rear torque distribution" in S210 and S212 of Fig. 9 is replaced with "-1-front / rear torque distribution."

[0082] For example, in the reverse mode, assume that the calculation unit 121 acquires "-1 Nm," "-3 Nm," "-2 Nm," and "-4 Nm" as the left front wheel torque, right front wheel torque, left rear wheel torque, and right rear wheel torque, respectively. In this case, the total torque is -10 Nm, so the reference value is "0 Nm." In this case, the calculation unit 121 calculates the torque offset value as "-(-1 Nm-3 Nm-2 Nm-4 Nm)-0 Nm = 10 Nm" (a modification of S103 in FIG. 4).

[0083] Based on the frame of FIG. 11, the analysis unit 221 calculates the torque command value (left front wheel torque) as "10 Nm × (-0.4) × 0.25 = -1 Nm." Based on the frame of FIG. 11, the analysis unit 221 also calculates the torque command value (right front wheel torque) as "10 Nm × (-0.4) × 0.75 = -3 Nm." Based on the frame of FIG. 11, the analysis unit 221 also calculates the torque command value (left rear wheel torque) as "10 Nm × (-1 - (-0.4)) × 0.33 = -2 Nm." Based on the frame of FIG. 11, the analysis unit 221 also calculates the torque command value (right rear wheel torque) as "10 Nm × (-1 - (-0.4)) × (1 - 0.33) = -4 Nm."

[0084] In this way, each inverter 24 drives the corresponding motor 31 in accordance with the torque command value obtained by analyzing the received frame in a manner according to the position of the wheel corresponding to the inverter 24 among the plurality of wheels. Furthermore, the controller 12 can transmit a frame including a torque command value whose absolute value indicates the torque command value and whose sign indicates the rotation direction of the wheel.

[0085] Therefore, the controller 12 does not need to send a control signal in an individual manner to each of the inverters 24. Furthermore, the controller 12 can realize not only forward movement of the vehicle 1 but also reverse movement of the vehicle 1 by transmitting a common frame.

[0086] (In-place turning mode) In the turn-in-place mode, the VCU 10 transmits a frame as shown in Fig. 12 to the wheel control device 20. Fig. 12 is a diagram showing an example of the frame.

[0087] As shown in Fig. 12, in the turn-on-the-spot mode, each value is positive. Also, as shown in Fig. 13, in the turn-on-the-spot mode, separate steering control is performed on the wheels 30. In the example of Fig. 13, if the direction parallel to the x-axis is set to 0 degrees, the left front wheel rotates about 60 degrees to the right, the right front wheel rotates about 60 degrees to the left, the left rear wheel rotates about 60 degrees to the left, and the right rear wheel rotates about 60 degrees to the right.

[0088] 13, the left front wheel and the left rear wheel 30 are controlled to rotate in the same direction as in the forward mode (the torque command value is in the positive direction). Also, the right front wheel and the right rear wheel 30 are controlled to rotate in the opposite direction to that in the forward mode (the torque command value is in the negative direction). As a result, the vehicle 1 turns to the right about an axis parallel to the z-axis.

[0089] Specifically, in the turn-in-place mode, the analysis unit 221 inverts the positive and negative signs of the torque command values ​​for the wheels depending on the turning direction in steps S206, S208, S210, and S212 of Fig. 9. For example, when the vehicle 1 turns right as shown in Fig. 13, the analysis unit 221 inverts the positive and negative signs of the right front wheel torque and the right rear wheel torque. Furthermore, when the vehicle 1 turns left, for example, the analysis unit 221 inverts the positive and negative signs of the left front wheel torque and the left rear wheel torque.

[0090] (Horizontal movement mode) In the lateral movement mode, the VCU 10 transmits a frame as shown in Fig. 14 to the wheel control device 20. Fig. 14 is a diagram showing an example of the frame.

[0091] As shown in Fig. 14, in the lateral movement mode, each value is positive. Also, as shown in Fig. 15, in the lateral movement mode, separate steering control is performed on the wheels 30. In the example of Fig. 15, if the direction parallel to the x-axis is set to 0 degrees, the left front wheel rotates about 90 degrees to the right, the right front wheel rotates about 90 degrees to the left, the left rear wheel rotates about 90 degrees to the left, and the right rear wheel rotates about 90 degrees to the right.

[0092] 15, the left front wheel and the right rear wheel 30 are controlled to rotate in the same direction as in the forward mode (the torque command value is in the positive direction). Also, the right front wheel and the left rear wheel 30 are controlled to rotate in the opposite direction to that in the forward mode (the torque command value is in the negative direction). As a result, the vehicle 1 moves laterally to the right (the positive direction of the y axis) while facing forward (the positive direction of the x axis).

[0093] Specifically, in the lateral movement mode, the analysis unit 221 inverts the positive and negative signs of the torque command values ​​for the wheels in the turning direction in steps S206, S208, S210, and S212 of Fig. 9. For example, when the vehicle 1 moves laterally to the right as shown in Fig. 15, the analysis unit 221 inverts the positive and negative signs of the right front wheel torque and the left rear wheel torque. Also, when the vehicle 1 moves laterally to the left, for example, the analysis unit 221 inverts the positive and negative signs of the left front wheel torque and the right rear wheel torque.

[0094] Each inverter 24 drives the corresponding motor 31 according to the torque command value obtained by analyzing the received frame in a manner that depends on the position of the wheel corresponding to the inverter 24 among the multiple wheels and whether the vehicle is in forward, reverse, turn-in-place, or lateral movement mode.

[0095] This allows the controller 12 to realize complex controls such as not only forward and reverse movement but also turning on the spot and lateral movement by transmitting a common frame.

[0096] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0097] 1 vehicle 10. VCU 11, 21 Interface 12, 22 Controller 13, 23 memory 20, 20LF, 20RF, 20LR, 20RR Wheel control device 24 inverters 30, 30LF, 30RF, 30LR, 30RR wheels 31 Motor 121 Calculation Department 122 Transmission control section 221 Analysis Department 222 Inverter control unit

Claims

1. A controller for controlling a motor provided on each of a plurality of wheels of a vehicle, The controller common data including an ID corresponding to a reference value of the control value and information regarding distribution of the control value to the plurality of wheels is transmitted to the inverters corresponding to each of the motors; Vehicle control device.

2. The controller Transmitting the data including a correction value for the reference value The vehicle control device according to claim 1 .

3. The controller Transmit the data including the distribution ratio of the control value between the front wheels and the rear wheels, the distribution ratio of the control value between the right front wheel and the left front wheel, and the distribution ratio of the control value between the right rear wheel and the left rear wheel. The vehicle control device according to claim 1 .

4. The controller transmit the data including the distribution ratio of the control value between the front wheels and the rear wheels, the distribution ratio of the control value between the right front wheel and the left front wheel, and the distribution ratio of the control value between the right rear wheel and the left rear wheel; The vehicle control device according to claim 3.

5. The controller The data includes a control value whose absolute value indicates a torque command value and whose sign indicates the rotation direction of the wheels. The vehicle control device according to claim 1 .

6. The controller transmit the data including a predetermined byte value indicating a correction value for the reference value, a predetermined byte value indicating a distribution ratio of the control value between the front wheels and the rear wheels, a predetermined byte value indicating a distribution ratio of the control value between the right front wheel and the left front wheel, and a predetermined byte value indicating a distribution ratio of the control value between the right rear wheel and the left rear wheel; The vehicle control device according to claim 1 .

7. a controller that controls a motor provided on each of a plurality of wheels of a vehicle; a motor provided on each of the plurality of wheels; an inverter provided corresponding to each of the plurality of wheels; A vehicle control system comprising: The controller transmitting common data to the inverter, the common data including an ID corresponding to a reference value of the control value and information regarding distribution of the control value to the plurality of wheels; Each of the inverters The motor corresponding to the wheel corresponding to the inverter is driven in accordance with a control value obtained by analyzing the received data in a manner according to the position of the wheel corresponding to the inverter among the plurality of wheels. Vehicle control system.

8. Each of the inverters The motor corresponding to the inverter is driven in accordance with a control value obtained by analyzing the received data in a manner according to the position of the wheel corresponding to the inverter among the plurality of wheels and whether the vehicle is in a forward, reverse, turn-on-the-spot, or lateral movement mode. The vehicle control system of claim 7.

9. A controller that controls a motor provided on each of a plurality of wheels of a vehicle, common data including an ID corresponding to a reference value of the control value and information regarding distribution of the control value to the plurality of wheels is transmitted to the inverters corresponding to each of the motors; A program that executes a process.

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