Motor control method and device and vehicle

Abstract

The embodiment of the invention provides a motor control method and device and a vehicle, by executing the method, a motor galloping prevention process can be periodically executed in the vehicle running process; in each process, when it is determined that the rotating speed and torque of the motor meet a first condition, the function of preventing the motor from galloping is activated; calculating a torque limit value based on the torque of the motor, the rotating speed change rate and the inertia of the driving wheel train, and limiting the rotating speed of the motor based on the torque limit value; and when determining that the rotating speed of the motor meets a second condition, closing the motor galloping prevention function. Motor control is carried out by periodically executing the motor galloping prevention process, in each period, after the motor galloping prevention function is activated, torque limiting operation can be carried out on the motor through the torque limiting value obtained through calculation to achieve galloping prevention processing on the motor, rapid response of torque control can be achieved, the processing efficiency is improved, and the motor galloping prevention effect is improved. The frequency of vehicle shaking caused by too high motor rotating speed is reduced, and the user driving experience is improved.

Description

Technical Field

[0001] This application relates to the technical field of motor control, and in particular, to a motor control method, device, and vehicle. Background Art

[0002] Currently, some motor controllers prevent the motor from racing by controlling the motor torque output to 0 Nm when the motor speed exceeds the maximum speed of the motor, and restricting the torque output to control the motor speed. In this control mode, the vehicle cannot be suppressed in the transient skidding condition, the response is slow, which may lead to vehicle out of control and poor subjective driving experience. Another control method is to calculate the motor speed change rate. When the motor speed change rate exceeds the threshold, the torque is restricted to control the motor speed. In this way, during the process of torque restriction, the motor speed keeps fluctuating, that is, the motor torque is constantly changing, resulting in vehicle jitter. Summary of the Invention

[0003] An embodiment of this application provides a motor control method, device, and vehicle. Through this method, the motor torque can be restricted based on the motor speed to prevent the motor from racing.

[0004] In a first aspect, an embodiment of this application provides a motor control method, including: during the vehicle driving process, periodically executing an anti-motor-racing process; wherein, the anti-motor-racing process includes: when it is determined that the speed and torque of the motor meet the first condition, activating the anti-motor-racing function; calculating a torque limit value based on the torque, speed change rate, and inertia of the drive train of the motor, and restricting the motor speed based on the torque limit value; when it is determined that the speed of the motor meets the second condition, turning off the anti-motor-racing function.

[0005] In a possible implementation manner, determining that the speed and torque of the motor meet the first condition includes: when it is recognized that the vehicle switches to the forward gear, if it is determined that the actual speed of the motor is greater than the first target speed and the motor requested torque is greater than the first torque, then it is determined that the speed and torque of the motor meet the first condition.

[0006] In a possible implementation manner, the speed and torque of the motor meet the first condition includes: when it is recognized that the vehicle switches to the reverse gear, if it is determined that the actual speed of the motor is greater than the second target speed and the motor requested torque is greater than the second torque, then it is determined that the speed and torque of the motor meet the first condition.

[0007] In a possible implementation manner, calculating the torque limit value based on the torque, speed change rate, and inertia of the drive system includes: calculating a drive system racing torque value according to the speed change rate and the inertia of the drive system; subtracting the torque of the motor from the drive system racing torque value to obtain the torque limit value.

[0008] In a possible implementation, the limiting of the motor speed based on the torque limit value includes: reducing the actual torque of the motor by the torque limit value; matching corresponding target PID parameters based on the speed difference between the target speed and the actual speed of the motor; and dynamically adjusting the battery torque based on the target PID parameters.

[0009] In a possible implementation, the speed differences between different target speeds and different actual speeds of the motor are pre-divided into multiple levels; and corresponding PID parameters are pre-configured based on the speed differences of multiple levels.

[0010] In a possible implementation, the determination that the speed of the motor satisfies the second condition includes: when the absolute value of the speed difference between the actual speed of the motor and the reference speed is less than the preset speed difference, it is determined that the speed of the motor satisfies the second condition.

[0011] In a possible implementation, after the function of preventing the motor from racing is turned off, the anti-motor racing process further includes: restoring the torque limit value of the motor and clearing the integral of the PID controller.

[0012] In a second aspect, an embodiment of the present application further provides a motor control device, which includes: a processor and a memory. The memory is used to store at least one instruction, and when the instruction is loaded and executed by the processor, it implements the motor control method provided in the first aspect.

[0013] In a third aspect, an embodiment of the present application provides a vehicle, which may include the motor control device provided in the second aspect.

[0014] Through the above technical solutions, the motor is controlled by periodically executing the anti-motor racing process. In each cycle, after the anti-motor racing function is activated, the torque of the motor can be limited by the calculated torque limit value to achieve the anti-motor racing process for the motor, which can achieve fast response of torque control, improve the processing efficiency, reduce the frequency of problems caused by too high motor speed resulting in vehicle jitter, and improve the user driving experience. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is the basic flowchart of the motor control method provided by an embodiment of the present application; Figure 2The specific flowchart of motor control provided by an embodiment of the present application; Figure 3 The schematic structural diagram of the motor control device provided by an embodiment of the present application. Specific implementation manners

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0018] Figure 1 The basic flowchart of the motor control method provided by an embodiment of the present application.

[0019] Referring to Figure 1 as shown, the motor control method may include: During the vehicle driving process, the anti-motor runaway process is periodically executed; wherein, the anti-motor runaway process includes: S101: When it is determined that the rotational speed and torque of the motor satisfy the first condition, the anti-motor runaway function is activated.

[0020] S102: Calculate the torque limit value based on the torque, rotational speed change rate of the motor, and the inertia of the drive train, and limit the rotational speed of the motor based on the torque limit value.

[0021] S103: When it is determined that the rotational speed of the motor satisfies the second condition, the anti-motor runaway function is turned off.

[0022] By periodically executing the anti-motor runaway process, it is possible to determine whether the motor satisfies the first condition by obtaining the rotational speed and torque of the motor, and when the first condition is satisfied, activate the anti-motor runaway function to achieve rapid function activation. After the function is activated, calculate the torque limit value based on the torque, rotational speed change rate of the motor, and the inertia of the drive train, and perform torque limitation to achieve rapid processing of torque control. After the rotational speed of the motor satisfies the second condition, control the function to be turned off. By periodically executing the above process, it is possible to achieve anti-motor runaway processing of the motor, realize rapid response of torque control, improve processing efficiency, reduce the problem of vehicle jitter caused by too high rotational speed of the motor, and improve the user driving experience.

[0023] Figure 2 The specific flowchart of motor control provided by an embodiment of the present application.

[0024] Referring to Figure 2 as shown, the specific process may beFigure 1 Specific implementation steps of the method shown

[0025] During the vehicle driving process, it is possible to determine how to determine whether the rotational speed and torque of the motor meet the first condition by obtaining the current gear information of the vehicle.

[0026] S201: Determine the vehicle gear information. When in the forward gear (D gear), execute S202a. If currently in the reverse gear (R gear), execute S202b.

[0027] S202a: Determine whether the actual rotational speed of the motor is greater than the first target rotational speed, and whether the motor requested torque is greater than the first torque. If so, execute S203. If not, control the end of this process.

[0028] S202b: Determine whether the actual rotational speed of the motor is greater than the second target rotational speed, and whether the motor requested torque is greater than the second torque. If so, execute S203. If not, control the end of this process.

[0029] In some embodiments, determining that the rotational speed and torque of the motor meet the first condition includes: When it is recognized that the vehicle switches to the forward gear, if it simultaneously satisfies that the actual rotational speed of the motor is greater than the first target rotational speed and the motor requested torque is greater than the first torque, then it is determined that the rotational speed and torque of the motor meet the first condition.

[0030] In some embodiments, determining that the rotational speed and torque of the motor meet the first condition includes: When it is recognized that the vehicle switches to the reverse gear, if it simultaneously satisfies that the actual rotational speed of the motor is greater than the second target rotational speed and the motor requested torque is greater than the second torque, then it is determined that the rotational speed and torque of the motor meet the first condition.

[0031] In some embodiments, if the actual rotational speed of the motor is not greater than the second target rotational speed, and / or the motor requested torque is not greater than the second torque, then it is determined that the rotational speed and torque of the motor do not meet the first condition.

[0032] In some embodiments, at the beginning of each anti-motor runaway process, the first target rotational speed and the second target rotational speed to be applied in this process can be calculated first, and the first torque and the second torque can be set. Among them, the first target rotational speed or the second target rotational speed can be obtained through corresponding calculations based on the reference rotational speed. Specifically, the reference rotational speed can be calculated based on the non-driving wheel rotational speed, tire radius, reduction gear ratio, and gear signal to obtain the reference rotational speed corresponding to the motor. Further, by magnifying the reference rotational speed according to the corresponding preset ratio, the first target rotational speed and the second target rotational speed can be calculated. It should be noted that the preset ratios used to calculate the first target rotational speed and the second target rotational speed respectively can be set based on the vehicle motor parameters and user requirements, and the present application does not limit this.

[0033] S203: Activate the function to prevent motor runaways.

[0034] When it is determined that the rotational speed and torque of the motor meet the first condition, the function to prevent the motor from running away can be activated.

[0035] S204: Calculate the torque limit value based on the torque, rotational speed change rate of the motor, and the inertia of the drive train.

[0036] In some embodiments, the specific calculation method of the torque limit value includes: calculating the runaway torque value of the drive system according to the rotational speed change rate and the inertia of the drive system; subtracting the torque of the motor from the runaway torque value of the drive system to obtain the torque limit value.

[0037] In one implementation, calculating the runaway torque value of the drive system according to the rotational speed change rate and the inertia of the drive system includes: 1. Calculate the angular acceleration of the motor shaft (unit: rad / s^2) = rotational speed change rate (unit: rpm / s) * 2Pi / 60; 2. Calculate the inertia of the drive system. According to the speed ratio relationship, convert the inertia of the tire, drive shaft, differential, reduction gear set, etc. to the equivalent inertia of the drive system on the motor shaft; 3. Calculate the runaway torque value of the drive system according to the angular acceleration of the motor shaft and the equivalent inertia of the drive system, and perform maximum / minimum value limitation.

[0038] Subtracting the torque of the motor from the runaway torque value of the drive system to obtain the torque limit value includes: Estimate the current road load torque by subtracting the runaway torque value of the drive system from the current actual torque of the motor, and use it as the feedforward torque value for closed-loop control.

[0039] In some embodiments, after calculating the torque limit, the rotational speed of the motor can be limited based on the torque limit value. In one implementation, limiting the rotational speed of the motor based on the torque limit value includes: S205: Reduce the actual torque of the motor by the torque limit value.

[0040] In some embodiments, the torque that causes the rotational speed of the motor to increase can be calculated according to the actual torque of the motor, the rotational speed change rate, and the inertia of the drive train, and the calculated torque can be used as the torque reduction value to control the motor, thereby achieving feedforward control of the torque of the motor.

[0041] S206: Match the corresponding target PID parameters based on the rotational speed difference between the target rotational speed and the actual rotational speed of the motor.

[0042] In some embodiments, the speed differences between different target speeds and different actual speeds of the motor are pre-divided into multiple levels, and the corresponding PID parameters are pre-configured based on the speed differences of multiple levels.

[0043] In some embodiments, the speed difference between the target speed and the actual speed of the motor can be calculated, and the PID parameters corresponding to the speed difference level are obtained by matching according to the corresponding level of the speed difference.

[0044] S207: Dynamically adjust the battery torque based on the target PID parameters.

[0045] In some embodiments, based on the PID parameters corresponding to the speed difference level, dynamic PID control can be performed on the motor to suppress the motor speed and prevent the motor from running away.

[0046] S208: Determine whether the absolute value of the speed difference between the actual speed of the motor and the reference speed is less than the preset speed difference. If so, execute S209; if not, return to S204.

[0047] S209: Turn off the function of preventing the motor from running away.

[0048] In some embodiments, when the absolute value of the speed difference between the actual speed of the motor and the reference speed is less than the preset speed difference and it is determined that the speed of the motor meets the second condition, S209 can be continued to be executed.

[0049] In some embodiments, when the absolute value of the speed difference between the actual speed of the motor and the reference speed is not less than the preset speed difference, it is determined that the current speed of the motor does not meet the second condition. Then, the motor needs to be continuously suppressed and return to S204 to continue executing the subsequent steps until it is determined that the speed of the motor meets the second condition, and then the function of preventing the motor from running away is turned off.

[0050] In some embodiments, in one anti-motor runaway process, after turning off the function of preventing the motor from running away, it further includes: restoring the torque limit value of the motor and clearing the integral of the PID controller. By clearing the integral of the anti-windup integrator, it is prevented that the integral term overshoots and affects the PID controller.

[0051] In some embodiments, periodically executing the anti-motor runaway process can include executing the anti-motor runaway process once every 1 ms, so as to achieve a fast response to the anti-motor runaway processing of the motor and reduce torque fluctuations at the same time.

[0052] Through the motor control method provided by the embodiments of the present application, feedforward control and dynamic PID control can be performed on the motor, which not only realizes fast response, reduces torque fluctuations at the same time, maximally maintains the torque output of the motor, improves the user driving experience, and ensures safe driving of the customer in this scenario.

[0053] Figure 3 Schematic structural diagram of a motor control device provided by an embodiment of the present application.

[0054] Referring to Figure 3 As shown, the motor control device may include a processor 301 and a memory 302. The memory 302 is used to store at least one instruction, and when the instruction is loaded and executed by the processor 301, it implements the motor control method provided by any embodiment of the present application.

[0055] An embodiment of the present application further provides a vehicle, which may include Figure 3 the motor control device provided by the embodiment shown, and the vehicle can also implement the motor control method provided by any embodiment of the present application based on the motor control device.

[0056] It should be noted that the terminals involved in the embodiments of the present application may include, but are not limited to, personal computers (PCs), personal digital assistants (PDAs), wireless handheld devices, tablet computers, mobile phones, MP3 players, MP4 players, etc.

[0057] It can be understood that the application may be a native application installed on the terminal, or it may also be a web application of a browser on the terminal. The embodiments of the present application do not limit this.

[0058] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the above-described systems, devices, and units can refer to the corresponding processes in the foregoing method embodiments, and will not be described herein again.

[0059] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0060] The unit described as a separation component may or may not be physically separated. The component displayed as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0061] In addition, each functional unit in various embodiments of the present application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a hardware plus software functional unit.

[0062] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit stored in a storage medium includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute some steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0063] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of protection of the present application.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present application.

Claims

1. A motor control method, characterized in that: The method comprises: During the driving process of the vehicle, the anti-motor runaway process is periodically executed; Wherein, the anti-motor runaway process includes: When it is determined that the speed and torque of the motor meet the first condition, activating the function of preventing the motor from running away; Calculating a torque limit value based on the torque of the motor, the speed change rate, and the inertia of the drive train, and limiting the motor speed based on the torque limit value; When it is determined that the rotation speed of the motor meets the second condition, the function of preventing the motor from running away is turned off.

2. The method according to claim 1, characterized in that Determining that the speed and torque of the motor meet the first condition includes: When it is recognized that the vehicle is switched to a forward gear, if it is determined that the actual speed of the motor is greater than the first target speed and the motor request torque is greater than the first torque, it is determined that the speed and torque of the motor meet the first condition.

3. The method according to claim 1, characterized in that Determining that the speed and torque of the motor meet the first condition includes: When it is recognized that the vehicle is switched to the reverse gear, if it is determined that the actual speed of the motor is greater than the second target speed and the motor request torque is greater than the second torque, it is determined that the speed and torque of the motor meet the first condition.

4. The method according to claim 1, characterized in that: The calculation of the torque limit value based on the torque of the motor, the speed change rate and the inertia of the drive system includes: Calculate the flying torque value of the drive system according to the speed change rate and the inertia of the drive system; The torque limit value is obtained by subtracting the torque of the motor from the overspeed torque value of the drive system.

5. The method according to claim 1 or 4, characterized in that: The limiting the motor speed based on the torque limit value comprises: reducing the actual torque of the motor by the torque limit value; Match the corresponding target PID parameters based on the speed difference between the target speed and the actual speed of the motor; The battery torque is dynamically adjusted based on the target PID parameter.

6. The method according to claim 5, characterized in that The speed difference between different target speeds and different actual speeds of the motor is divided into multiple levels in advance; The corresponding PID parameters are pre-configured based on multiple levels of speed differences.

7. The method according to claim 1, characterized in that Determining that the rotation speed of the motor satisfies the second condition includes: When the absolute value of the speed difference between the actual speed of the motor and the reference speed is less than the preset speed difference, it is determined that the speed of the motor meets the second condition.

8. The method according to claim 1, characterized in that After the motor runaway prevention function is turned off, the motor runaway prevention process further includes: Restore the motor's torque limit value and clear the integral of the PID controller.

9. A motor control device, characterized in that: The device comprises: A processor and a memory, wherein the memory is used to store at least one instruction, and when the instruction is loaded and executed by the processor, the motor control method according to any one of claims 1 to 8 is implemented.

10. A vehicle, characterized in that: The vehicle includes the motor control device according to claim 9.

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