Motor speed transmission system and method for vehicle

Abstract

The present invention relates to a motor speed transmission system and method for a vehicle. A motor speed transmission system for a vehicle is disclosed, the vehicle includes a wheel hub motor, and the motor speed transmission system includes: a vehicle control unit; a motor control unit for calculating the motor speed of the wheel hub motor; a bus; and a serial port cable. The vehicle control unit is configured to send first data including a first time to the motor control unit through the serial port cable. The motor control unit is configured to calculate the current motor speed after receiving the first data from the vehicle control unit, and send second data including a second time and the calculated motor speed to the vehicle control unit through the bus, wherein the second time is obtained by adding the motor speed calculation time of the motor control unit to the first time.

Description

Technical Field

[0001] The present invention relates to the technical field of wheel hub motors for vehicles, and more specifically to a motor speed transmission system and method for vehicles. Background Art

[0002] Compared with fuel vehicles, electric vehicles use batteries as their main energy source and are driven by drive motors. Depending on the location of the drive motors, they can be divided into single-motor centralized drive electric vehicles, dual-motor distributed drive electric vehicles, and hub motor driven electric vehicles.

[0003] In the field of autonomous driving, vehicle speed is a key factor in making decisions. In an electric vehicle driven by a hub motor, the vehicle speed is directly related to the motor speed, so the vehicle speed can be calculated based on the motor speed. Usually, for vehicles without wheel speed sensors (such as autonomous vehicles), the vehicle control unit (VCU) needs to obtain the motor speed from the motor control unit (MCU) via the bus. It is expected that the motor speed is accurately and without delay input into the vehicle control unit. However, due to environmental influences such as electromagnetic interference or limitations of bus transmission (such as low data priority), the transmission of the motor speed to the vehicle control unit is often delayed or lost. If the motor speed is transmitted through the bus in a shorter period (such as 1ms), it may cause the bus network to overload, so this does not solve the problem. At the same time, if there are multiple (for example, four) hub motors, the vehicle control unit needs to synchronize all motor speed signals, and the problem becomes more complicated.

[0004] Therefore, a more timely motor speed transmission system and method is needed. Summary of the invention

[0005] One object of the present invention is to provide a more timely motor speed transmission system and method. Another object of the present invention is to provide a motor speed transmission system and method without wheel speed sensors.

[0006] One aspect of the present invention provides a transmission system, a motor speed transmission system for a vehicle, the vehicle including a hub motor, the motor speed transmission system including: a vehicle control unit; a motor control unit for calculating the motor speed of the hub motor; a bus; and a serial port cable, wherein the vehicle control unit is configured to send first data including a first time to the motor control unit via the serial port cable, and the motor control unit is configured to calculate the current motor speed after receiving the first data from the vehicle control unit, and send second data including a second time and the calculated motor speed to the vehicle control unit via the bus, wherein the second time is obtained by adding the first time to the motor speed calculation time of the motor control unit.

[0007] According to an embodiment of the invention, the bus is a Controller Area Network (CAN) bus.

[0008] According to an embodiment of the present invention, the serial port cable is an RS 232 cable.

[0009] According to an embodiment of the present invention, the vehicle control unit is further configured to calculate the vehicle speed based on the second time and the calculated motor speed after receiving the second data from the motor control unit.

[0010] Another aspect of the present invention provides a method for transmitting the motor speed of a vehicle, the vehicle including a hub motor, the motor speed transmission method including: controlling a vehicle control unit of the vehicle to send first data including a first time to a motor control unit of the vehicle via a serial cable; and after the motor control unit receives the first data from the vehicle control unit, controlling the motor control unit to calculate the current motor speed, and controlling the motor control unit to send second data including a second time and the calculated motor speed to the vehicle control unit via a bus, wherein the second time is obtained by adding the first time to the motor speed calculation time of the motor control unit.

[0011] According to an embodiment of the present invention, the second data is sent to the vehicle control unit via a controller area network bus.

[0012] According to an embodiment of the present invention, the first data is sent to the motor control unit through an RS 232 cable.

[0013] According to an embodiment of the present invention, the motor speed transmission method further includes: after receiving the second data from the motor control unit, controlling the vehicle control unit to calculate the vehicle speed based on the second time and the calculated motor speed.

[0014] Another aspect of the present invention provides a computer-readable storage medium storing computer-executable instructions, wherein when the instructions are executed by a processor, a motor speed transmission method according to an embodiment of the present invention is implemented.

[0015] Another aspect of the present invention provides a vehicle, comprising: a wheel hub motor; and a motor speed transmission system according to an embodiment of the present invention.

[0016] According to an embodiment of the present invention, first, a serial cable such as RS 232 is used to send time data from a vehicle control unit to a motor control unit. Since the level signal is sent directly without being restricted by the bus, it can be considered that the first time is sent to the motor control unit without delay. Afterwards, the motor control unit sends the calculated motor speed and the second time back to the vehicle control unit via the bus. Since the second time is composed of the first time and the motor speed calculation time, the vehicle control unit can identify the actual detection time of the received motor speed. Therefore, the vehicle control unit can avoid using the delayed motor speed to calculate the vehicle speed, so that the vehicle speed can be calculated more accurately and applied to vehicle control. At the same time, even in a vehicle without a wheel speed sensor, the motor control unit can provide the vehicle control unit with accurate and timely motor speed. When there are multiple (for example, four) wheel hub motors, the vehicle control unit can send time data to multiple motor control units. Thereby, the vehicle control unit can synchronize the generation time of the motor speed from each motor control unit and control multiple wheel hub motors more conveniently. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a motor speed transmission system according to an embodiment of the present invention.

[0018] Figure 2 is a flow chart of a motor speed transmission method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention are described with reference to the accompanying drawings. The following detailed description and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, and the present invention is not limited to the preferred embodiments described. The scope of the present invention is defined by the claims. The present invention is now described in detail with reference to exemplary embodiments, and some embodiments are illustrated in the accompanying drawings. The following description is made with reference to the accompanying drawings, and unless otherwise indicated, the same reference numerals in different drawings represent the same or similar elements. The schemes described in the following exemplary embodiments do not represent all schemes of the present invention. On the contrary, these schemes are merely examples of systems and methods of various aspects of the present invention involved in the appended claims.

[0020] Figure 1 Schematic diagram of a motor speed transmission system according to an embodiment of the present invention. Figure 1 As shown, the motor speed transmission system according to an embodiment of the present invention comprises: a vehicle control unit (VCU) 10, a motor control unit (MCU) 20, a bus 30 and a serial port cable 40. The motor speed transmission system according to the present invention can be installed on an electric vehicle, in particular, a hub motor driven electric vehicle.

[0021] The vehicle control unit 10 is used to receive the motor speed from the motor control unit 20 and calculate the vehicle speed. The motor control unit 20 is used to obtain the motor speed, such as the speed of the wheel hub motor, and output the motor speed to the vehicle control unit 10. The vehicle control unit 10 and the motor control unit 20 are respectively connected in communication via a bus 30 and a serial cable 40. In an exemplary embodiment, the bus 30 is a controller area network (CAN) bus. In an exemplary embodiment, the serial cable 40 is an RS 232 cable.

[0022] Figure 2 is a flow chart of a motor speed transmission method according to an embodiment of the present invention. Figure 1 and Figure 2 Describe the motor speed transmission method.

[0023] In step S10, the vehicle control unit 10 sends first data including a first time to the motor control unit 20 via the serial port cable 40. The first time is the real time when the vehicle control unit 10 sends the first data. In an exemplary embodiment, the resolution of the first time sent by the vehicle control unit 10 can be 1 second. The first time is in the form of a binary code. In some embodiments, the first time can be expressed as xx hours yy minutes zz seconds, such as 10h 11min 12s. For example, the binary code of the first time can include 8 bits, of which 0-23 hours are 2 bits, 0-59 minutes are 3 bits, and 0-59 seconds are 3 bits.

[0024] The serial port cable 40 is used to transmit a level signal. A high level and a low level represent logic 0 and 1, respectively. In some embodiments, a high level represents a logic 1 and a low level represents a logic 0. In some embodiments, a high level represents a logic 0 and a low level represents a logic 1. The serial port cable 40 can directly send time data from the vehicle control unit to the motor control unit. Since the level signal is directly sent without being limited by the bus, it can be considered that the first time is sent to the motor control unit without delay.

[0025] In step S20 , after receiving the first data from the vehicle control unit 10 , the motor control unit 20 calculates the current motor speed and sends second data including the second time and the calculated motor speed to the vehicle control unit 10 through the bus 30 .

[0026] In an exemplary embodiment, the resolution of the second time sent by the motor control unit 20 can be 1 millisecond. The second time is in binary code form. In some embodiments, the second time can be expressed as xx hours yy minutes zz seconds aaa milliseconds, such as 10h 11min 12s 123ms. For example, the binary code of the second time can include 17 bits, of which 0-23 hours is 2 bits, 0-59 minutes is 3 bits, 0-59 seconds is 3 bits, 0-999 milliseconds is 9 bits, and 2 bits are reserved.

[0027] It should be noted that the second time includes two parts, the first part is the first time from the vehicle control unit 10 (eg xx hours yy minutes zz seconds), and the second part is the time used by the motor control unit 20 to calculate the motor speed, ie the motor speed calculation time.

[0028] According to an embodiment of the present invention, the motor speed transmission method may further include: after the vehicle control unit 10 receives the second data from the motor control unit 20 , the vehicle control unit 10 calculates the vehicle speed based on the second time and the calculated motor speed.

[0029] In the case where there are multiple (for example, four) wheel hub motors and multiple motor control units, the vehicle control unit 10 can send the first data including the first time to the multiple motor control units through the serial port cable 40. Thus, the vehicle control unit 10 can synchronize the generation time of the motor speed from each motor control unit through the first time, and control the multiple wheel hub motors more conveniently.

[0030] An embodiment of the present invention provides a computer-readable storage medium storing a computer program, which implements any of the methods described in the above embodiments when executed by a processor.

[0031] It should be understood that the various parts of the present invention can be implemented with hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented with software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented with hardware, it can be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0032] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0033] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the configuration and method of the above-described embodiments. On the contrary, the present invention is intended to cover various modifications and equivalent configurations. In addition, although the various elements and method steps of the disclosed invention are shown in various exemplary combinations and configurations, other combinations including more or less elements or methods also fall within the scope of the present invention.

Claims

1. A motor speed transmission system for a vehicle, the vehicle comprising a wheel hub motor, the motor speed transmission system include: Vehicle control unit; A motor control unit, used for calculating the motor speed of the wheel hub motor; bus; and Serial cable, The vehicle control unit is configured to send first data including a first time to the motor control unit through the serial port cable, and The motor control unit is configured to calculate the current motor speed after receiving the first data from the vehicle control unit, and send second data including a second time and the calculated motor speed to the vehicle control unit via the bus, wherein the second time is obtained by adding the first time to the motor speed calculation time of the motor control unit.

2. The motor speed transmission system according to claim 1, in, The bus is a Controller Area Network (CAN) bus.

3. The motor speed transmission system according to claim 1 or 2, in, The serial port cable is an RS 232 cable.

4. The motor speed transmission system according to claim 3, in, The vehicle control unit is further configured to calculate a vehicle speed based on the second time and the calculated motor speed after receiving the second data from the motor control unit.

5. A method for transmitting the motor speed of a vehicle, wherein the vehicle includes a wheel hub motor, and the motor speed transmission method include: A vehicle control unit controlling the vehicle sends first data including a first time to a motor control unit of the vehicle through a serial port cable; and After the motor control unit receives the first data from the vehicle control unit, the motor control unit is controlled to calculate the current motor speed, and the motor control unit is controlled to send second data including a second time and the calculated motor speed to the vehicle control unit through a bus, wherein the second time is obtained by adding the first time to the motor speed calculation time of the motor control unit.

6. The motor speed transmission method according to claim 5, in, The second data is sent to the vehicle control unit via a controller area network bus.

7. The motor speed transmission method according to claim 5 or 6, in, The first data is sent to the motor control unit through an RS 232 cable.

8. The motor speed transmission method according to claim 7, further comprising: include: After receiving the second data from the motor control unit, the vehicle control unit is controlled to calculate the vehicle speed based on the second time and the calculated motor speed.

9. A computer-readable storage medium storing computer-executable instructions, in, When the instructions are executed by a processor, the motor speed transmission method according to any one of claims 5 to 8 is implemented.

10. A vehicle, include: Hub motor; and A motor speed transmission system according to any one of claims 1 to 4.

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