Control method for brushless direct-current motor in vehicle, storage medium, and vehicle

Abstract

The present invention relates to the technical field of motor control. Disclosed are a control method for a brushless direct-current motor in a vehicle, a storage medium, and a vehicle. The method comprises: acquiring a sensor signal, a position instruction, and a first current signal, wherein the sensor signal is used for determining the current position of a rotor of a brushless direct-current motor, the position instruction is used for determining an expected position of the rotor, and the first current signal is used for controlling the speed and direction of the brushless direct-current motor; processing the sensor signal, the position instruction, and the first current signal to obtain a motor control instruction; and on the basis of the motor control instruction, controlling the brushless direct-current motor to work. The present invention solves the technical problems of low control efficiency and high cost caused by the need for calibrating motor parameters in control methods for brushless direct-current motors provided by the related art.

Description

Control method of brushless DC motor in vehicle, storage medium and vehicle Technical Field

[0001] The present invention relates to the field of motor control technology, and in particular to a control method for a brushless DC motor in a vehicle, a storage medium, and the vehicle. Background Art

[0002] As vehicle functionality demands grow, the trend toward higher-speed and more integrated motors is becoming increasingly evident. Electronic control solutions based on motors, due to their superior response characteristics, are gradually replacing traditional hydraulic control solutions. Motors are widely used in steering, shifting, and other work scenarios that require fast response. Currently, brushless DC motors are commonly used in vehicles to assist with steering, shifting, and other actions. However, existing control methods for brushless DC motors in vehicles require manual calibration of motor parameters, resulting in high labor and test bench resource costs, as well as low motor control efficiency. This, in turn, results in long vehicle response times to user requests for steering and shifting, making it impossible to meet user driving needs.

[0003] From the above analysis, it can be seen that the control methods of brushless DC motors provided by the above-mentioned related technologies require calibration of motor parameters, resulting in low control efficiency and high cost. Currently, no effective solution has been proposed.

[0004] Summary of the Invention

[0005] Embodiments of the present invention provide a control method for a brushless DC motor in a vehicle, a storage medium, and a vehicle, to at least solve the technical problem that the control method for a brushless DC motor provided by the related art requires calibration of motor parameters, resulting in low control efficiency and high cost.

[0006] According to one aspect of an embodiment of the present invention, a method for controlling a brushless DC motor in a vehicle is provided, comprising:

[0007] Acquire a sensor signal, a position command, and a first current signal, wherein the sensor signal is used to determine the current position of the rotor of the brushless DC motor, the position command is used to determine the desired position of the rotor, and the first current signal is used to control the speed and direction of the brushless DC motor; process the sensor signal, the position command, and the first current signal to obtain a motor control command; and control the operation of the brushless DC motor according to the motor control command.

[0008] Optionally, the motor control instruction includes a target modulation instruction and a duty cycle instruction, wherein the target modulation instruction is used to control the rotor rotation of the brushless DC motor or to control the brushless DC motor to enter a safe state, and the duty cycle instruction is used to determine the amplitude and frequency of the inverter output voltage. The sensor signal, position instruction and first current signal are processed to obtain the motor control instruction, including: processing the sensor signal and position instruction to obtain the first current instruction; determining the target modulation instruction according to the first current instruction; and determining the duty cycle instruction according to the first current instruction and the first current signal.

[0009] Optionally, the sensor signal and the position instruction are processed to obtain a first current instruction, including: processing the sensor signal to obtain a first position signal of the rotor, wherein the first position signal is used to characterize the current position of the rotor; limiting the slope of the position instruction to obtain an expected position instruction; and performing operations on the first position signal and the expected position instruction to obtain a first current instruction.

[0010] Optionally, the sensor signal is processed to obtain a first position signal of the rotor, including: inputting the sensor signal into a preset numbering rule to obtain a second position signal; during the rotation of the rotor, determining a position offset value based on a third position signal and a fourth position signal of the rotor, wherein the third position signal is a position signal of the rotor in a current rotation cycle, and the fourth position signal is a position signal of the rotor in a previous rotation cycle; and determining a statistical value of the second position signal based on the third position signal and the position offset value.

[0011] Optionally, the target modulation instruction includes a first modulation instruction, wherein the first modulation instruction is a modulation instruction corresponding to the target modulation mode, and the target modulation instruction is determined based on the first current instruction, including: limiting the slope of the first current instruction to obtain a second current instruction; determining the target modulation mode based on a preset modulation mode mapping table and the sign of the second current instruction; and generating the first modulation instruction corresponding to the target modulation mode.

[0012] Optionally, a duty cycle instruction is determined based on the first current instruction and the first current signal, including: calculating the first current signal to obtain a second current signal, wherein the second current signal is an amplitude signal corresponding to the first current signal; filtering the second current signal to obtain a third current signal; in response to the control mode of the brushless DC motor being a position control mode, limiting the slope of the first current instruction to obtain a second current instruction; and operating the second current instruction and the third current signal to obtain a duty cycle instruction.

[0013] Optionally, the control method of the brushless DC motor in the above vehicle further includes: in response to the control mode of the brushless DC motor being a current control mode, controlling the brushless DC motor to operate according to a preset current instruction.

[0014] Optionally, the control method of the brushless DC motor in the above-mentioned vehicle also includes: generating a second modulation instruction in response to a fault in the control circuit of the brushless DC motor, wherein the second modulation instruction is used to control the brushless DC motor to enter a safe state, and the priority of the second modulation instruction is higher than the priority of the first modulation instruction.

[0015] According to another aspect of an embodiment of the present invention, there is provided a control device for a brushless DC motor in a vehicle, comprising:

[0016] An acquisition module is configured to acquire a sensor signal, a position instruction, and a first current signal, wherein the sensor signal is used to determine the current position of the rotor of the brushless DC motor, the position instruction is used to determine the desired position of the rotor, and the first current signal is used to control the speed and direction of the brushless DC motor; a processing module is configured to process the sensor signal, the position instruction, and the first current signal to obtain a motor control instruction; and a control module is configured to control the operation of the brushless DC motor according to the motor control instruction.

[0017] Optionally, the above-mentioned processing module is also configured as follows: the motor control instruction includes a target modulation instruction and a duty cycle instruction, wherein the target modulation instruction is used to control the rotor rotation of the DC brushless motor or to control the DC brushless motor to enter a safe state, and the duty cycle instruction is used to determine the amplitude and frequency of the inverter output voltage, and the sensor signal, position instruction and first current signal are processed to obtain the motor control instruction, including: processing the sensor signal and position instruction to obtain the first current instruction; determining the target modulation instruction according to the first current instruction; and determining the duty cycle instruction according to the first current instruction and the first current signal.

[0018] Optionally, the above-mentioned processing module is also configured to: process the sensor signal and the position instruction to obtain a first current instruction, including: processing the sensor signal to obtain a first position signal of the rotor, wherein the first position signal is used to characterize the current position of the rotor; limiting the slope of the position instruction to obtain an expected position instruction; performing operations on the first position signal and the expected position instruction to obtain a first current instruction.

[0019] Optionally, the above-mentioned processing module is also configured to: process the sensor signal to obtain a first position signal of the rotor, including: inputting the sensor signal into a preset numbering rule to obtain a second position signal; during the rotation of the rotor, determining a position offset value based on a third position signal and a fourth position signal of the rotor, wherein the third position signal is a position signal of the rotor in a current rotation cycle, and the fourth position signal is a position signal of the rotor in a previous rotation cycle; and determining a statistical value of the second position signal based on the third position signal and the position offset value.

[0020] Optionally, the above-mentioned processing module is also configured to: the target modulation instruction includes a first modulation instruction, wherein the first modulation instruction is a modulation instruction corresponding to the target modulation mode, and the target modulation instruction is determined according to the first current instruction, including: limiting the slope of the first current instruction to obtain a second current instruction; determining the target modulation mode according to a preset modulation mode mapping table and the sign of the second current instruction; and generating the first modulation instruction corresponding to the target modulation mode.

[0021] Optionally, the above-mentioned processing module is also configured to: determine a duty cycle instruction based on the first current instruction and the first current signal, including: calculating the first current signal to obtain a second current signal, wherein the second current signal is an amplitude signal corresponding to the first current signal; filtering the second current signal to obtain a third current signal; in response to the control mode of the DC brushless motor being a position control mode, limiting the slope of the first current instruction to obtain a second current instruction; and operating the second current instruction and the third current signal to obtain a duty cycle instruction.

[0022] Optionally, the control device of the brushless DC motor in the above vehicle further includes: a second control module, configured to control the operation of the brushless DC motor according to a preset current instruction in response to the control mode of the brushless DC motor being a current control mode.

[0023] Optionally, the control device of the brushless DC motor in the above-mentioned vehicle also includes: a third control module, which is configured to generate a second modulation instruction in response to a fault in the control circuit of the brushless DC motor, wherein the second modulation instruction is used to control the brushless DC motor to enter a safe state, and the priority of the second modulation instruction is higher than the priority of the first modulation instruction.

[0024] According to another aspect of an embodiment of the present invention, a storage medium is further provided, the storage medium including a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute any of the aforementioned methods for controlling a brushless DC motor in a vehicle.

[0025] According to another aspect of an embodiment of the present invention, a vehicle is provided, comprising an on-board memory and an on-board processor, wherein a computer program is stored in the on-board memory, and the on-board processor is configured to run the computer program to execute any one of the aforementioned methods for controlling a brushless DC motor in a vehicle.

[0026] In an embodiment of the present invention, a sensor signal, a position instruction, and a first current signal are first acquired, wherein the sensor signal is used to determine the current position of the rotor of the brushless DC motor, the position instruction is used to determine the desired position of the rotor, and the first current signal is used to control the speed and direction of the brushless DC motor. Then, the sensor signal, the position instruction, and the first current signal are processed to obtain a motor control instruction. Finally, the brushless DC motor is controlled to operate according to the motor control instruction. By determining the modulation instruction and the duty cycle instruction for controlling the operation of the brushless DC motor based on the acquired sensor signal, position instruction, and current signal, the purpose of controlling the operation of the brushless DC motor without calibrating the motor parameters is achieved, thereby achieving the technical effect of improving the control efficiency of the brushless DC motor and reducing the labor cost and the bench resource cost, thereby solving the technical problem that the control method of the brushless DC motor provided by the related art requires the calibration of the motor parameters, resulting in low control efficiency and high cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] 1 is a hardware structure block diagram of a vehicle terminal for an optional control method of a brushless DC motor in a vehicle according to an embodiment of the present invention;

[0029] FIG2 is a flow chart of a method for controlling a brushless DC motor in a vehicle according to an embodiment of the present invention;

[0030] FIG3 is a schematic diagram of an optional control process of a brushless DC motor in a vehicle according to an embodiment of the present invention;

[0031] FIG4 is a schematic diagram of position numbering of an optional brushless DC motor according to an embodiment of the present invention;

[0032] FIG5 is a schematic diagram of another optional control process of a brushless DC motor in a vehicle according to an embodiment of the present invention;

[0033] 6 is a structural block diagram of a control device for a brushless DC motor in a vehicle according to an embodiment of the present invention;

[0034] 7 is a structural block diagram of another optional control device for a brushless DC motor in a vehicle according to an embodiment of the present invention;

[0035] FIG8 is a structural block diagram of another optional control device for a brushless DC motor in a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] According to an embodiment of the present invention, a method embodiment of a method for controlling a brushless DC motor in a vehicle is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0039] FIG1 is a block diagram of the hardware structure of a vehicle terminal for an optional method of controlling a brushless DC motor in a vehicle according to an embodiment of the present invention. As shown in FIG1 , the vehicle terminal (or a mobile device having a communication association with the vehicle) may include one or more processors 102 (the processor 102 may include, but is not limited to, a processing device such as a microcontroller unit (MCU) or a programmable logic device (FPGA)), a memory 104 configured to store data, and a transmission device 106 configured to implement a communication function. In addition, it may also include: a display device 110, an input / output device 108 (i.e., an IO device), a universal serial bus (USB) port (which may be included as one of the ports of a computer bus, not shown in the figure), a network interface (not shown in the figure), a power supply (not shown in the figure), and / or a camera (not shown in the figure). It will be understood by those skilled in the art that the structure shown in FIG1 is merely illustrative and does not limit the structure of the vehicle terminal 1 described above. For example, the vehicle terminal may also include more or fewer components than those shown in FIG1 , or have a configuration different from that shown in FIG1 .

[0040] It should be noted that the one or more processors 102 and / or other data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuit may be a single independent processing module, or may be fully or partially integrated into any of the other components in the vehicle terminal (or mobile device).

[0041] The memory 104 can be configured to store software programs and modules for application software, such as the program instructions / data storage device corresponding to the control method for a brushless DC motor in a vehicle in an embodiment of the present invention. The processor 102 executes the software programs and modules stored in the memory 104 to perform various functional applications and data processing, thereby implementing the control method for a brushless DC motor in a vehicle. The memory 104 can include a high-speed random access memory and can also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 can further include a memory remotely located relative to the processor 102, and these remote memories can be connected to the vehicle terminal via a network. Examples of the aforementioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0042] The transmission device 106 is configured to receive or transmit data via a network. A specific example of such a network may include a wireless network provided by a communications provider of the vehicle terminal. In one embodiment, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to enable communication with the Internet. In another embodiment, the transmission device 106 may be a radio frequency (RF) module configured to communicate with the Internet wirelessly.

[0043] Under the above operating environment, an embodiment of the present invention provides a control method for a brushless DC motor in a vehicle as shown in Figure 2. Figure 2 is a flow chart of a control method for a brushless DC motor in a vehicle according to an embodiment of the present invention. As shown in Figure 2, the embodiment shown in Figure 2 may include at least the following implementation steps, that is, it may be a technical solution implemented by steps S21 to S23.

[0044] Step S21, acquiring a sensor signal, a position command, and a first current signal, wherein the sensor signal is used to determine a current position of a rotor of the brushless DC motor, the position command is used to determine a desired position of the rotor, and the first current signal is used to control a speed and direction of the brushless DC motor;

[0045] Step S22, processing the sensor signal, the position command and the first current signal to obtain a motor control command;

[0046] Step S23: Control the brushless DC motor to operate according to the motor control instruction.

[0047] In the technical solutions provided in steps S21 to S23 above, the sensor signals may be Hall signals from one or more Hall sensors. It should also be noted that one or more Hall sensors may be installed on the stator of a brushless DC motor, and the Hall sensors determine the rotor position by sensing the magnetic poles on the rotor. The position command may be a position command issued by a controller or microprocessor in the vehicle's brushless DC motor control system, and the position command may include the speed and direction of the brushless DC motor.

[0048] In the technical solution provided in steps S21 to S23 above, the first current signal can be a three-phase current signal of a three-phase brushless DC motor. This three-phase current signal can be transmitted and processed by a brushless DC motor driver. Specifically, the driver can receive commands from a controller and convert these commands into corresponding current signals to drive the brushless DC motor. The motor control commands can act on an inverter in the vehicle's brushless DC motor control system to control parameters such as the inverter output voltage waveform and the time ratio between high and low levels. This can then determine motor parameters such as the speed, torque, amplitude, and frequency of the brushless DC motor to control its operation.

[0049] In an embodiment of the present invention, a sensor signal, a position instruction, and a first current signal are first acquired, wherein the sensor signal is used to determine the current position of the rotor of the brushless DC motor, the position instruction is used to determine the desired position of the rotor, and the first current signal is used to control the speed and direction of the brushless DC motor. Then, the sensor signal, the position instruction, and the first current signal are processed to obtain a motor control instruction. Finally, the brushless DC motor is controlled to operate according to the motor control instruction. By determining the modulation instruction and the duty cycle instruction for controlling the operation of the brushless DC motor based on the acquired sensor signal, position instruction, and current signal, the purpose of controlling the operation of the brushless DC motor without calibrating the motor parameters is achieved, thereby achieving the technical effect of improving the control efficiency of the brushless DC motor and reducing the labor cost and the bench resource cost, thereby solving the technical problem that the control method of the brushless DC motor provided by the related art requires the calibration of the motor parameters, resulting in low control efficiency and high cost.

[0050] The above method of the embodiment of the present invention is further introduced below.

[0051] In an optional embodiment, in step S22, the motor control instruction includes a target modulation instruction and a duty cycle instruction, wherein the target modulation instruction is used to control the rotor rotation of the brushless DC motor or to control the brushless DC motor to enter a safe state, and the duty cycle instruction is used to determine the amplitude and frequency of the inverter output voltage. The sensor signal, the position instruction, and the first current signal are processed to obtain the motor control instruction, including:

[0052] Step S221, processing the sensor signal and the position command to obtain a first current command;

[0053] Step S222, determining a target modulation instruction according to the first current instruction;

[0054] Step S223: determining a duty cycle command according to the first current command and the first current signal.

[0055] In the technical solution provided by the above steps S221 to S223, the above-mentioned first current instruction can reduce the error between the actual position of the brushless DC motor determined based on the sensor signal and the desired position of the brushless DC motor determined based on the position instruction, so as to improve the accuracy of the control position of the brushless DC motor. The above-mentioned target modulation instruction can be used to change the waveform of the output voltage of the inverter in the control system of the vehicle brushless DC motor to control the speed and torque of the brushless DC motor. The above-mentioned duty cycle instruction can be used to control the time ratio of the high level and low level of the inverter output voltage. It should also be noted here that the duty cycle instruction can control the amplitude and frequency of the inverter output voltage by changing the duty cycle of the inverter switch tube, thereby affecting the amplitude and frequency of the brushless DC motor.

[0056] In an optional embodiment, in step S221, the sensor signal and the position instruction are processed to obtain a first current instruction, including:

[0057] Step S2211: Process the sensor signal to obtain a first position signal of the rotor, wherein the first position signal is used to represent the current position of the rotor;

[0058] Step S2212, limiting the slope of the position command to obtain the desired position command;

[0059] Step S2213: Calculate the first position signal and the expected position command to obtain a first current command.

[0060] The above method is further described below with reference to FIG3 .

[0061] Figure 3 is a schematic diagram of an optional control process of a brushless DC motor in a vehicle according to an embodiment of the present invention. As shown in Figure 3, the control system of the brushless DC motor in the vehicle includes: a current calculation unit 301, a current filtering unit 302, a position command slope limiting unit 303, a sector number calculation unit 304, a sector position statistics unit 305, a position control PI (Proportional-Integral) unit 306, a current command slope limiting unit 307, a mode control unit 308, a current control PI unit 309, a modulation mode judgment unit 310, a CCW (Counter-Clockwise) modulation unit 311, a CW (Clockwise) modulation unit 312, a fault judgment unit 313, an active short-circuit unit 314, an inverter 315, and a three-phase brushless DC motor 316.

[0062] Still as shown in Figure 3, in the process of controlling the three-phase DC brushless motor 316, the acquired three-phase Hall signal (sensor signal) is first processed to obtain the actual position signal of the motor rotor (first position signal). At the same time, the position instruction slope limiting unit 303 is used to limit the slope of the acquired position instruction to obtain the expected position instruction. Then, the position control PI unit 306 is used to perform proportional link operations and integral link operations on the actual position signal and the expected position instruction to obtain the first current instruction.

[0063] In the technical solution provided by the present invention, it should also be noted that the process of limiting the slope of the position command can be: first, determining the target position and the starting position according to the position command, and calculating the change in the position command, then calculating the change in the position command within each control cycle according to a preset rising slope or a preset falling slope, and then comparing the change in the position command within each control cycle with the actual position to determine the control strategy of the motor. Specifically, when the change in the position command is less than the change in the position command within each control cycle, control is performed according to the preset rising slope or the preset falling slope, and the output of the motor is adjusted in real time; when the change in the position command is greater than the change in the position command within each control cycle, the position command is set to the target position, and the motor outputs the maximum speed. Furthermore, during the control process of the motor, the output of the motor is adjusted in real time according to the feedback information of the actual position to reduce the error between the actual position and the target position.

[0064] In an optional embodiment, in step S2211, processing the sensor signal to obtain a first position signal of the rotor includes:

[0065] Step S22111, inputting the sensor signal into a preset numbering rule to obtain a second position signal;

[0066] Step S22112: During the rotation of the rotor, determine a position offset value based on a third position signal and a fourth position signal of the rotor, wherein the third position signal is a position signal of the rotor in a current rotation cycle, and the fourth position signal is a position signal of the rotor in a previous rotation cycle;

[0067] Step S22113: Determine a statistical value of the second position signal according to the third position signal and the position offset value.

[0068] The above method will be further described below with reference to FIG3 , FIG4 and FIG5 .

[0069] Still as shown in FIG3 , in the technical solution provided by the present invention, the sector number calculation unit 304 can input the acquired three-phase Hall signal into a preset numbering rule to obtain a corresponding sector number value and display the sector number (second position signal) of the motor rotor. FIG4 is a schematic diagram of an optional position numbering of a brushless DC motor according to an embodiment of the present invention. As shown in FIG4 , as an optional implementation, the position of the brushless DC motor rotor can be divided into six sectors, and each sector can be numbered in a clockwise direction as follows: 1, 2, 3, 4, 5, 6.

[0070] Still as shown in FIG3 , the sector position statistics unit 305 can further calculate the total number of sectors that the brushless DC motor has rotated through, thereby representing the actual position of the brushless DC motor. Specifically, after each low-voltage power supply to the system, the current sector position is recorded as 0. When the rotor rotates in a preset positive direction (clockwise or counterclockwise), the position signal is increased by 1 each time a sector is passed. Conversely, when rotating in the reverse direction, the position signal is decreased by 1 each time a sector is passed.

[0071] FIG5 is a schematic diagram of another optional control process of a brushless DC motor in a vehicle according to an embodiment of the present invention. As shown in FIG5 , as an optional implementation, the positive direction is preset to be clockwise. During the rotation of the motor rotor, the sector signal section_input (third position signal) of the current rotation cycle and the sector signal section_input_z (fourth position signal) of the previous rotation cycle are collected. When section_input is 6 and section_input_z is 1, it indicates that the motor rotor rotates in the counterclockwise direction. At this time, the position offset value offset is reduced by 1; when section_input is 1 and section_input_z is 6, it indicates that the motor rotor rotates in the clockwise direction. At this time, the position offset value offset is increased by 1; when the above two conditions are not met, the position offset value offset is not changed. Finally, the statistical value counter_output of the sector number where the motor rotor is currently located is determined according to the sector signal section_input and the position offset value offset of the current rotation cycle. It can be shown in the following formula (1):

[0072] counter_output=section_input+6×offset formula (1)

[0073] In an optional embodiment, in step S222, the target modulation instruction includes a first modulation instruction, wherein the first modulation instruction is a modulation instruction corresponding to the target modulation mode, and determining the target modulation instruction according to the first current instruction includes:

[0074] Step S2221, limiting the slope of the first current command to obtain a second current command;

[0075] Step S2222, determining a target modulation mode according to a preset modulation mode mapping table and the sign of the second current instruction;

[0076] Step S2223: Generate a first modulation instruction corresponding to the target modulation mode.

[0077] Still as shown in Figure 3, the current command slope limiting unit 307 limits the slope of the first current command obtained by the position control PI unit 306 to obtain a limited current command (a second current command). Based on the sign of the limited current command, the corresponding target modulation mode is determined from the preset modulation mode mapping table. As an optional embodiment, in the preset modulation mode mapping table, when the sign of the limited current command is positive, the target modulation mode is CCW modulation; when the sign of the limited current command is negative, the target modulation mode is CW modulation.

[0078] Still as shown in FIG3 , in the technical solution provided by the present invention, a modulation mode flag can be set to represent the target modulation mode. After determining the modulation mode flag corresponding to the sign of the limited current command, the CCW modulation unit 311 or CW modulation unit 312 is determined based on the modulation mode flag, and the corresponding modulation command (first modulation command) is generated. Specifically, the CCW modulation unit 311 can control the motor rotor to rotate in a counterclockwise direction, and the CW modulation unit 312 can control the motor rotor to rotate in a clockwise direction.

[0079] In the technical solution provided by the present invention, it should also be noted that when the rotor of the brushless DC motor is in the six different sectors of the hexagon shown in Figure 4, it can correspond to different modulation methods, and the target modulation method of the rotor in each sector can be adjusted according to actual needs, thereby improving the flexibility of the control method of the brushless DC motor.

[0080] In an optional embodiment, in step S223, determining a duty cycle instruction according to the first current instruction and the first current signal includes:

[0081] Step S2231, calculating the first current signal to obtain a second current signal, wherein the second current signal is an amplitude signal corresponding to the first current signal;

[0082] Step S2232, filtering the second current signal to obtain a third current signal;

[0083] Step S2233: In response to the control mode of the brushless DC motor being the position control mode, limiting the slope of the first current command to obtain a second current command;

[0084] Step S2234: Calculate the second current command and the third current signal to obtain a duty cycle command.

[0085] Still as shown in Figure 3, in the current calculation unit 301, the obtained three-phase current signal (first current signal) is calculated to determine the current amplitude signal (second current signal). As an optional embodiment, the control system of the vehicle DC brushless motor can use three Hall sensors to perform six-step control. In each modulation cycle, two phases of the three-phase DC brushless motor are in the on state. Thus, the current amplitude signal can be half of the sum of the absolute values ​​of the three-phase current signals. Furthermore, the calculated current amplitude signal is filtered in the current filtering unit 302. The filtering method may include but is not limited to: first-order low-pass filtering, weighted average filtering, to obtain the actual current signal (third current signal).

[0086] Still as shown in FIG. 3 , the technical solution provided by the present invention can switch the control mode of the brushless DC motor according to the switching instruction of the mode control unit 308 . The control mode may include, but is not limited to, a position control mode and a current control mode. As an optional embodiment, when switching to the position control mode, the slope of the first current instruction is limited to obtain a limited current instruction as the desired current instruction. Subsequently, the current control PI unit 309 performs proportional and integral operations on the desired current instruction and the actual current signal to obtain a duty cycle instruction. Thus, the first modulation instruction and the duty cycle instruction are used to control the inverter 315.

[0087] In the technical solution provided by the present invention, it should also be noted that the six-step control process of the three Hall sensors can include: Step 1: Initialization, setting the parameters of the Hall sensor (such as working mode, resolution, gain) to initial values; Step 2: Reading data, reading the current Hall signal of the Hall sensor; Step 3: Data processing, processing the read Hall signal (such as filtering, calibration, compensation); Step 4: Judgment condition, judging whether the processed Hall signal exceeds the preset threshold or preset numerical range; Step 5: Control action, executing the corresponding control action according to the judgment result (such as triggering an alarm when exceeding the preset numerical range); Step 6: Loop control, cyclically executing steps 1 to 5 to monitor and control the Hall sensor in real time, improve the accuracy of the Hall signal and the stability of the system.

[0088] In an optional embodiment, the control method of the brushless DC motor in the vehicle further includes:

[0089] Step S24 , in response to the control mode of the brushless DC motor being the current control mode, controlling the brushless DC motor to operate according to a preset current instruction.

[0090] Still as shown in FIG3 , when the mode control unit 308 switches the control mode of the brushless DC motor to the current control mode, a preset current command can be obtained. This preset current command is input as the desired current command to the current control PI unit 309. Proportional and integral operations are performed on this preset current command and the actual current signal processed by the current filter unit 302 to obtain a duty cycle command. It should also be noted that this preset current command can be set by a technician based on the control requirements of the three-phase brushless DC motor, thereby increasing the flexibility of the control method for the brushless DC motor in a vehicle provided by the present invention.

[0091] In an optional embodiment, the control method of the brushless DC motor in the vehicle further includes:

[0092] Step S25 : In response to a fault in the control circuit of the brushless DC motor, a second modulation instruction is generated, wherein the second modulation instruction is used to control the brushless DC motor to enter a safe state, and a priority of the second modulation instruction is higher than a priority of the first modulation instruction.

[0093] As shown in Figure 3 , during the control process of the three-phase brushless DC motor 316, the fault determination unit 313 can detect in real time whether the motor has a fault. When it is determined that the motor has a fault, the fault flag can be set to a high level, thereby activating the active short-circuit function to control the motor to enter a safe state. Specifically, when the fault flag is high, the active short-circuit unit 314 generates a modulation instruction (a second modulation instruction) corresponding to the active short-circuit. Then, the modulation instruction is input to the inverter 315. The inverter 315 controls the three-phase brushless DC motor 316 to enter a safe state based on the received modulation instruction and duty cycle instruction.

[0094] Still as shown in FIG3 , in the technical solution provided by the present invention, it should be noted that the inverter 315 receives one of the modulation instructions corresponding to the three units, namely, the active short-circuit unit 314, the CCW modulation unit 311, and the CW modulation unit 312, at each moment, and the second modulation instruction corresponding to the active short-circuit unit 314 has a higher priority than the first modulation instructions corresponding to the CCW modulation unit 311 and the CW modulation unit 312, so that when a fault is detected in the three-phase DC brushless motor 316, the motor rotor is stopped from rotating. Moreover, the duty cycle instruction changes according to the second modulation instruction to cooperate with the second modulation instruction to control the three-phase DC brushless motor 316 to enter a safe state. It should be noted that the duty cycle instruction corresponding to the motor fault can be pre-set to a fixed value or a value that changes according to a preset rule.

[0095] The control method of the brushless DC motor in the vehicle provided by the present invention can achieve the following technical effects:

[0096] (1) Without calibrating the motor parameters, the DC brushless motor is controlled by using the modulation command and duty cycle command obtained by processing the three-phase Hall signal, position command and three-phase current signal, which improves the control efficiency of the DC brushless motor and reduces the labor cost and bench resource cost;

[0097] (2) The switching process of multiple control modes of the brushless DC motor is realized, which improves the flexibility of the motor control method;

[0098] (3) When the motor fails, an active short-circuit method is adopted to quickly protect the system, which further improves the flexibility of the motor control method and enhances the reliability and safety of the control system.

[0099] In this embodiment, a control device for a brushless DC motor in a vehicle is also provided. The device is configured to implement the above-described embodiments and preferred embodiments, and details already described are omitted. As used below, a "module" refers to a combination of software and / or hardware that can implement a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0100] FIG6 is a structural block diagram of a control device for a brushless DC motor in a vehicle according to an embodiment of the present invention. As shown in FIG6 , the device includes:

[0101] an acquisition module 601 configured to acquire a sensor signal, a position command, and a first current signal, wherein the sensor signal is used to determine a current position of a rotor of the brushless DC motor, the position command is used to determine a desired position of the rotor, and the first current signal is used to control a speed and direction of the brushless DC motor;

[0102] The processing module 602 is configured to process the sensor signal, the position command and the first current signal to obtain a motor control command;

[0103] The control module 603 is configured to control the operation of the brushless DC motor according to the motor control instruction.

[0104] Optionally, the above-mentioned processing module 602 is also configured as follows: the motor control instruction includes a target modulation instruction and a duty cycle instruction, wherein the target modulation instruction is used to control the rotor rotation of the DC brushless motor or to control the DC brushless motor to enter a safe state, and the duty cycle instruction is used to determine the amplitude and frequency of the inverter output voltage, and the sensor signal, position instruction and first current signal are processed to obtain the motor control instruction, including: processing the sensor signal and position instruction to obtain the first current instruction; determining the target modulation instruction according to the first current instruction; and determining the duty cycle instruction according to the first current instruction and the first current signal.

[0105] Optionally, the above-mentioned processing module 602 is also configured to: process the sensor signal and the position instruction to obtain a first current instruction, including: processing the sensor signal to obtain a first position signal of the rotor, wherein the first position signal is used to characterize the current position of the rotor; limiting the slope of the position instruction to obtain an expected position instruction; and performing operations on the first position signal and the expected position instruction to obtain a first current instruction.

[0106] Optionally, the processing module 602 is further configured to: process the sensor signal to obtain a first position signal of the rotor, including: inputting the sensor signal into a preset numbering rule to obtain a second position signal; during the rotation of the rotor, determining a position offset value based on a third position signal and a fourth position signal of the rotor, wherein the third position signal is a position signal of the rotor in a current rotation cycle, and the fourth position signal is a position signal of the rotor in a previous rotation cycle; and determining a statistical value of the second position signal based on the third position signal and the position offset value.

[0107] Optionally, the above-mentioned processing module 602 is also configured to: the target modulation instruction includes a first modulation instruction, wherein the first modulation instruction is a modulation instruction corresponding to the target modulation mode, and the target modulation instruction is determined according to the first current instruction, including: limiting the slope of the first current instruction to obtain a second current instruction; determining the target modulation mode according to a preset modulation mode mapping table and the sign of the second current instruction; and generating the first modulation instruction corresponding to the target modulation mode.

[0108] Optionally, the above-mentioned processing module 602 is also configured to: determine a duty cycle instruction based on the first current instruction and the first current signal, including: calculating the first current signal to obtain a second current signal, wherein the second current signal is an amplitude signal corresponding to the first current signal; filtering the second current signal to obtain a third current signal; in response to the control mode of the brushless DC motor being a position control mode, limiting the slope of the first current instruction to obtain a second current instruction; and operating the second current instruction and the third current signal to obtain a duty cycle instruction.

[0109] Optionally, Figure 7 is a structural block diagram of another optional control device for a DC brushless motor in a vehicle according to an embodiment of the present invention. As shown in Figure 7, in addition to all the modules shown in Figure 6, the device also includes: a second control module 604, which is configured to control the operation of the DC brushless motor according to a preset current instruction in response to the control mode of the DC brushless motor being a current control mode.

[0110] Optionally, Figure 8 is a structural block diagram of another optional control device for a brushless DC motor in a vehicle according to an embodiment of the present invention. As shown in Figure 8, in addition to all the modules shown in Figure 7, the device also includes: a third control module 605, which is configured to generate a second modulation instruction in response to a fault in the control circuit of the brushless DC motor, wherein the second modulation instruction is used to control the brushless DC motor to enter a safe state, and the priority of the second modulation instruction is higher than the priority of the first modulation instruction.

[0111] It should be noted that the above modules can be implemented through software or hardware. For the latter, it can be implemented in the following ways, but not limited to: the above modules are all located in the same processor; or the above modules are located in different processors in any combination.

[0112] According to another aspect of an embodiment of the present invention, a storage medium is further provided, the storage medium including a stored program, wherein when the program is running, the device where the storage medium is located is controlled to execute any of the aforementioned methods for controlling a brushless DC motor in a vehicle.

[0113] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0114] Step S1, acquiring a sensor signal, a position command, and a first current signal, wherein the sensor signal is used to determine a current position of a rotor of a brushless DC motor, the position command is used to determine a desired position of the rotor, and the first current signal is used to control a speed and direction of the brushless DC motor;

[0115] Step S2, processing the sensor signal, the position command and the first current signal to obtain a motor control command;

[0116] Step S3: Control the brushless DC motor to operate according to the motor control instruction.

[0117] Optionally, in this embodiment, the above-mentioned storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store computer programs.

[0118] According to another aspect of an embodiment of the present invention, a vehicle is provided, comprising an on-board memory and an on-board processor, wherein a computer program is stored in the on-board memory, and the on-board processor is configured to run the computer program to execute any one of the aforementioned methods for controlling a brushless DC motor in a vehicle.

[0119] Optionally, in this embodiment, the vehicle-mounted processor may be configured to execute the following steps via a computer program:

[0120] Step S1, acquiring a sensor signal, a position command, and a first current signal, wherein the sensor signal is used to determine a current position of a rotor of a brushless DC motor, the position command is used to determine a desired position of the rotor, and the first current signal is used to control a speed and direction of the brushless DC motor;

[0121] Step S2, processing the sensor signal, the position command and the first current signal to obtain a motor control command;

[0122] Step S3: Control the brushless DC motor to operate according to the motor control instruction.

[0123] Optionally, specific examples in this embodiment may refer to the examples described in the above embodiment and its optional implementation manners, and this embodiment will not be described in detail here.

[0124] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0125] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0126] In the several embodiments provided herein, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units described may be based on logical functions. In actual implementation, other divisions may be employed, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through interfaces, or indirect coupling or communication connection between units or modules, which may be electrical or otherwise.

[0127] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0128] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0129] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, magnetic disk or optical disk, etc., various media that can store program code.

[0130] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for controlling a brushless DC motor in a vehicle, comprising: Acquire a sensor signal, a position command, and a first current signal, wherein the sensor signal is used to determine a current position of a rotor of a brushless DC motor, the position command is used to determine a desired position of the rotor, and the first current signal is used to control a speed and a direction of the brushless DC motor; Processing the sensor signal, the position command and the first current signal to obtain a motor control command; The brushless DC motor is controlled to operate according to the motor control instruction.

2. The control method according to claim 1, wherein: The motor control instruction includes a target modulation instruction and a duty cycle instruction, wherein the target modulation instruction is used to control the rotor rotation of the DC brushless motor or to control the DC brushless motor to enter a safe state, and the duty cycle instruction is used to determine the amplitude and frequency of the inverter output voltage. The sensor signal, the position instruction and the first current signal are processed to obtain the motor control instruction, including: Processing the sensor signal and the position command to obtain a first current command; determining the target modulation instruction according to the first current instruction; The duty cycle command is determined according to the first current command and the first current signal.

3. The control method according to claim 2, wherein: Processing the sensor signal and the position instruction to obtain the first current instruction includes: Processing the sensor signal to obtain a first position signal of the rotor, wherein the first position signal is used to represent a current position of the rotor; Limiting the slope of the position command to obtain a desired position command; The first position signal and the expected position command are operated to obtain the first current command.

4. The control method according to claim 3, wherein: Processing the sensor signal to obtain the first position signal of the rotor includes: Inputting the sensor signal into a preset numbering rule to obtain a second position signal; During the rotation of the rotor, a position offset value is determined based on a third position signal and a fourth position signal of the rotor, wherein the third position signal is a position signal of the rotor in a current rotation cycle, and the fourth position signal is a position signal of the rotor in a previous rotation cycle; A statistical value of the second position signal is determined according to the third position signal and the position offset value.

5. The control method according to claim 2, wherein: The target modulation instruction includes a first modulation instruction, wherein the first modulation instruction is a modulation instruction corresponding to a target modulation mode, and determining the target modulation instruction according to the first current instruction includes: Limiting the slope of the first current command to obtain a second current command; Determining the target modulation mode according to a preset modulation mode mapping table and the sign of the second current instruction; Generate the first modulation instruction corresponding to the target modulation mode.

6. The control method according to claim 2, wherein: Determining the duty cycle instruction according to the first current instruction and the first current signal includes: Calculating the first current signal to obtain a second current signal, wherein the second current signal is an amplitude signal corresponding to the first current signal; filtering the second current signal to obtain a third current signal; In response to the control mode of the brushless DC motor being a position control mode, limiting the slope of the first current instruction to obtain a second current instruction; The second current command and the third current signal are operated to obtain the duty cycle command.

7. The control method according to claim 1, wherein: The method further comprises: In response to the control mode of the brushless DC motor being a current control mode, the brushless DC motor is controlled to operate according to a preset current instruction.

8. The control method according to claim 1, wherein: The method further comprises: In response to a fault in the control circuit of the brushless DC motor, a second modulation instruction is generated, wherein the second modulation instruction is used to control the brushless DC motor to enter a safe state, and a priority of the second modulation instruction is higher than a priority of the first modulation instruction.

9. A storage medium comprising a stored program, wherein: When the program is running, the device where the storage medium is located is controlled to execute the control method of the brushless DC motor in a vehicle as claimed in any one of claims 1 to 8.

10. A vehicle, comprising an on-board memory and an on-board processor, wherein the on-board memory stores a computer program, and the on-board processor is configured to run the computer program to execute the control method of the brushless DC motor in the vehicle according to any one of claims 1 to 8.

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