Rotating speed pulsation suppression method and system based on active damping, controller and medium

Abstract

The invention relates to the technical field of automobile control, in particular to a rotating speed pulsation suppression method and system based on active damping, a controller and a medium. When the parking heating condition is met, the motor is controlled to enter a parking heating mode, a d-axis exciting current instruction is given, and a real-time rotating speed signal of a motor rotor is obtained; based on the real-time rotating speed signal, active damping torque used for restraining rotor swinging is calculated through a damping control algorithm, and the direction of the active damping torque is opposite to the rotating direction of the rotor; according to the active damping torque and the d-axis exciting current instruction, a final q-axis current instruction is obtained through calculation and used for controlling the motor. By introducing an active damping mechanism based on rotating speed feedback, on the premise that a hardware structure is not changed and heating power is not affected, back-and-forth swinging of a motor rotor near a zero position caused by a gear backlash of a transmission system and tiny disturbance is effectively restrained, rotating speed fluctuation is remarkably reduced, the problem of vehicle body shaking is solved, and the service life of a vehicle is prolonged. And the smoothness of the whole vehicle and the system stability are improved.

Description

Technical Field

[0001] This disclosure relates to the field of automotive control technology, and in particular to a method, system, controller, and medium for suppressing speed pulsation based on active damping. Background Technology

[0002] With the rapid development of new energy vehicle technology, the performance of electric vehicles (including pure electric vehicles and hybrid electric vehicles) in low-temperature environments is receiving increasing attention. In low-temperature environments, the charging and discharging efficiency of the power battery decreases significantly, while the heating needs of vehicle occupants increase. To address this issue, existing electric vehicles are typically equipped with an active parking heating function. The basic principle of this function is that when the vehicle is parked, a DC excitation current (usually the d-axis current Id) is applied to the stator windings of the motor through the motor controller. Due to the internal resistance of the stator windings, Joule heat (Id) is generated when the DC current flows through it. 2 R), thereby heating the coolant inside the motor. The heated coolant flows through the battery pack or cabin heat exchanger, further increasing the battery temperature or heating the cabin.

[0003] In an ideal parking heating mode, the motor only needs to provide a heat source. Theoretically, the motor rotor should remain stationary (i.e., its speed is 0) and not output electromagnetic torque. Therefore, the control strategy typically sets the q-axis current command Iq and applies only the d-axis excitation current.

[0004] However, in practical engineering applications, due to the unavoidable tooth backlash in vehicle transmission systems (such as reducers and differentials), and the nonlinear, uneven distribution of mechanical friction at low speeds, the motor rotor is prone to slight back-and-forth oscillations near zero. Specifically, when only excitation current is applied, even minor disturbances in the current loop or slight changes in the load can cause the rotor to oscillate freely within the tooth backlash. This minute mechanical oscillation can be captured by a high-precision speed sensor (such as a rotary transformer), forming alternating positive and negative speed fluctuation signals (e.g., oscillating between -50 rpm and +50 rpm).

[0005] Such speed fluctuations can have a series of negative effects, not only affecting the overall smoothness of the vehicle and causing body vibration, but also potentially triggering misjudgments by the control system: First, speed fluctuations are transmitted to the vehicle body through the transmission system, causing vehicle vibration and abnormal noises, which seriously reduces the vehicle's smoothness and NVH (noise, vibration, and harshness) performance, affecting the comfort experience of passengers.

[0006] Secondly, fluctuating speed signals may lead to misjudgments by the motor controller or vehicle controller. For example, the controller may mistakenly interpret the vehicle as having a driving intention or a malfunction, thereby triggering unnecessary control mode switching or fault protection logic.

[0007] Finally, if the rotor repeatedly impacts between the teeth, long-term operation may exacerbate mechanical wear and shorten the service life of the transmission system.

[0008] Existing suppression methods mostly focus on adjusting the PI parameters of the current loop or adding hardware filtering, but they often fail to fundamentally eliminate low-frequency oscillations caused by mechanical gaps, and are complex to calibrate and have poor versatility.

[0009] The following solutions are commonly used in existing technologies: The first approach is to optimize the current loop PI parameters. By adjusting the proportional and integral gain of the current loop, the accuracy and stability of the current response are improved, indirectly suppressing speed fluctuations. However, this method mainly targets disturbances caused by electromagnetic factors, and its suppression effect on low-frequency mechanical oscillations caused by mechanical tooth backlash is very limited. Furthermore, adjusting the PI parameters often requires a difficult trade-off between response speed and system stability, and the calibration process is complex, lacks versatility, and is difficult to adapt to differences in different vehicle models or motor platforms.

[0010] The second approach is to add hardware filtering or damping devices. For example, a hardware low-pass filter can be added to the signal acquisition circuit to filter out speed fluctuation signals; or a physical damper can be added to the mechanical system to dissipate oscillation energy. While these methods can alleviate fluctuations to some extent, they increase hardware costs and system complexity, and hardware filters cannot be dynamically adjusted according to real-time operating conditions, making them less adaptable to intermittent oscillations with randomness and nonlinearity.

[0011] In summary, the existing technology lacks a technical solution that can effectively solve the rotor oscillation and speed fluctuation problems caused by the tooth backlash of the transmission system in the parking heating mode of electric vehicles without increasing hardware costs or affecting heating efficiency. Summary of the Invention

[0012] To address the aforementioned issues, this disclosure provides a method, system, controller, and medium for suppressing speed pulsation based on active damping. Addressing the problem in existing electric vehicles operating in parking heating mode where backlash and minor disturbances in the transmission system cause the motor rotor to oscillate near zero, leading to speed fluctuations and vehicle vibration, this disclosure provides a method for suppressing speed pulsation based on active damping. This method effectively suppresses speed fluctuations and improves overall vehicle smoothness without altering the hardware or affecting the heating power.

[0013] The first aspect is a method for suppressing speed pulsation based on active damping, including: The system acquires vehicle status signals and controls the motor to enter parking heating mode when the parking heating conditions are met. In the parking heating mode, set the initial q-axis current command, give the d-axis excitation current command for generating heat, and obtain the real-time speed signal of the motor rotor. Based on the real-time speed signal, the active damping torque used to suppress rotor oscillation is calculated through a damping control algorithm. The direction of the active damping torque is opposite to the direction of rotor rotation. Substituting the active damping torque and d-axis excitation current command into the torque formula, the final q-axis current command is calculated. The motor is controlled according to the d-axis excitation current command and the final q-axis current command to suppress rotor oscillation near zero position caused by backlash in the transmission system.

[0014] Furthermore, when the parking heating conditions are met, the motor is controlled to enter the parking heating mode, including: When the vehicle controller detects that the ambient temperature is lower than the preset threshold, the vehicle is stationary, and the vehicle safety is met, it sends a command to the motor controller to enter the parking active heating mode.

[0015] Furthermore, based on the real-time speed signal, an active damping torque for suppressing rotor oscillation is calculated using a damping control algorithm, including: Calculate the active damping torque using the following formula: Tdamp ( k ) = Kp · oh ( k ) in, Tdamp ( k () represents the active damping torque in the k-th period. Kp This is the active damping coefficient. oh ( k () represents the real-time speed signal, and the negative sign indicates that the direction of the active damping torque is opposite to the direction of the speed.

[0016] Furthermore, based on the real-time speed signal, an active damping torque for suppressing rotor oscillation is calculated using a damping control algorithm, including: The real-time speed signal is filtered to remove high-frequency noise and obtain the filtered speed signal. Calculate the active damping torque using the following formula: Tdamp ( k ) = Kp · oh ( k ) in, Tdamp ( k () represents the active damping torque with period k. Kp This is the active damping coefficient. oh ( k ) represents the speed signal after k-cycle filtering, and the negative sign indicates that the direction of the active damping torque is opposite to the direction of the speed.

[0017] Furthermore, the real-time speed signal is filtered, specifically using a first-order low-pass filter algorithm, the discrete expression of which is: oh ( k )= α · oh ( k )+(1 α )· oh ( k 1) in, oh ( k () represents the real-time rotational speed signal with k periods. oh ( k 1) is the filtered rotational speed signal with a period of k-1, where α is the filtering coefficient, which is determined by the sampling period and the cutoff frequency.

[0018] Furthermore, the active damping coefficient Kp The methods for determining this include: The parking heating mode was operated in a bench environment that included the backlash of the transmission system teeth; Gradually adjust the active damping coefficient Kp The value; Monitor the amplitude of motor speed fluctuations and the q-axis current response; Select a value that ensures the speed fluctuation amplitude is less than a preset threshold and that the q-axis current does not oscillate. Kp The value is used as the final calibration value.

[0019] Furthermore, it also includes exit control steps: Real-time monitoring of ambient temperature, battery temperature, or vehicle status; When the temperature reaches the preset target value, or when a signal indicating the vehicle's intention to drive is received, the motor is controlled to exit the parking heating mode. When exiting the parking heating mode, the active damping torque is set to zero, and the q-axis current command is reset to 0.

[0020] Secondly, a speed pulsation suppression system based on active damping includes: Parking heating start unit, speed signal acquisition unit, active damping torque calculation unit, q-axis current command calculation unit, and suppression control unit; The parking heating start unit is used to acquire vehicle status signals and control the motor to enter the parking heating mode when the parking heating conditions are met. The speed signal acquisition unit is used to set the initial q-axis current command, give the d-axis excitation current command for generating heat, and acquire the real-time speed signal of the motor rotor in the parking heating mode. The active damping torque calculation unit calculates the active damping torque used to suppress rotor oscillation based on the real-time speed signal and through a damping control algorithm. The direction of the active damping torque is opposite to the direction of rotor rotation. The q-axis current command calculation unit is used to substitute the active damping torque and the d-axis excitation current command into the torque formula to calculate the final q-axis current command. The suppression control unit is used to control the motor according to the d-axis excitation current command and the final q-axis current command to suppress rotor oscillation near zero position caused by backlash in the transmission system.

[0021] Thirdly, a motor controller includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, which stores computer programs; When the processor executes the computer program stored in the memory, it implements the above-mentioned method for suppressing speed pulsation based on active damping.

[0022] Fourthly, a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for suppressing rotational speed pulsations based on active damping.

[0023] Fifthly, an electric vehicle including the aforementioned motor controller.

[0024] This disclosure includes at least the following beneficial effects: When the parking heating conditions are met, this disclosure controls the motor to enter the parking heating mode, provides a d-axis excitation current command, and acquires the real-time speed signal of the motor rotor. Based on the real-time speed signal, an active damping torque for suppressing rotor oscillation is calculated through a damping control algorithm. The direction of the active damping torque is opposite to the direction of rotor rotation. According to the active damping torque and the d-axis excitation current command, the final q-axis current command is calculated and used for motor control. This disclosure, by introducing an active damping mechanism based on speed feedback, effectively suppresses the back-and-forth oscillation of the motor rotor near zero position caused by transmission system tooth backlash and minor disturbances, without changing the hardware structure or affecting the heating power. This significantly reduces speed fluctuations, solves the vehicle body vibration problem, and improves overall vehicle smoothness and system stability.

[0025] Other features and advantages of this disclosure will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the disclosure. The objects and other advantages of this disclosure may be realized and obtained by means of the structures pointed out in the description and the accompanying drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the suppression method according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram illustrating the principle of the suppression method in the embodiments of this disclosure; Figure 3 This is a schematic diagram of the suppression system architecture according to an embodiment of the present disclosure; Figure 4 This is a schematic diagram of the motor controller structure according to an embodiment of the present disclosure. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0029] like Figure 1 As shown, the speed pulsation suppression method based on active damping includes: S101: Obtain vehicle status signal; when parking heating conditions are met, control the motor to enter parking heating mode. S102, in the parking heating mode, set the initial q-axis current command, give the d-axis excitation current command for generating heat, and obtain the real-time speed signal of the motor rotor. S103, based on the real-time speed signal, calculates the active damping torque used to suppress rotor sway through a damping control algorithm. The direction of the active damping torque is opposite to the direction of rotor rotation. S104: Substitute the active damping torque and d-axis excitation current command into the torque formula to calculate the final q-axis current command. S105 controls the motor according to the d-axis excitation current command and the final q-axis current command to suppress rotor oscillation near zero position caused by backlash in the transmission system.

[0030] In specific implementation, such as Figure 2 As shown, the process is as follows: Enter parking heating mode and initialize parameters: When the vehicle controller detects that the ambient temperature is below a preset threshold (e.g., -10℃), the vehicle is stationary, and other safety conditions are met, it sends a command to the motor controller to enter the active parking heating mode. The motor controller responds to the command, sets the basic q-axis command Iq=0, and provides a preset excitation current command Id (e.g., -285A), while activating the active damping control module disclosed herein.

[0031] Real-time motor speed acquisition: The motor rotor position is acquired in real time using a resolver sensor or other position sensor, and the actual rotational speed ω(k) for the current control cycle is calculated. The rotational speed value includes a positive or negative sign to indicate the direction of rotation.

[0032] (Optional) Perform low-pass filtering on the speed signal: To prevent sensor noise or high-frequency interference from being introduced into the damping torque, the original rotational speed ω(k) is low-pass filtered to obtain the filtered rotational speed ω. f (k). The filter can be a first-order low-pass digital filter, with the cutoff frequency set according to the system bandwidth and fluctuation frequency, for example, 100Hz. Its discretization expression is: oh ( k )= α · oh ( k )+(1 α )· oh ( k 1) Where α is the filter coefficient, which is determined by the sampling period and the cutoff frequency.

[0033] Calculate the active damping torque: The filtered speed oh ( k Input a preset damping control model. This disclosure uses the simplest proportional controller (P controller) to generate active damping torque: Tdamp ( k ) = Kp · oh ( k ) in: Tdamp ( k ) represents the active damping torque (in Nm or corresponding current value) for the current k-cycle. Kp The active damping coefficient needs to be pre-calibrated and is a positive real number; the negative sign indicates that the damping torque direction is always opposite to the rotational speed direction, forming negative feedback.

[0034] The physical meaning of this formula: when the rotor rotates in the forward direction ( oh ( k When the rotor rotates in the opposite direction ( )>0), a reverse torque is applied to try to pull it back to zero; when the rotor rotates in the opposite direction ( ) oh ( k When () < 0), a positive torque is applied. This effect is equivalent to adding a viscous damping term to the mechanical system, with a damping coefficient of . Kp .

[0035] Command to add damping torque to the q-axis: The calculated active damping torque Tdamp ( k Based on the basic d-axis current command Id, and according to the torque formula, the final q-axis current command is calculated.

[0036] Then we can obtain:

[0037] Perform current closed-loop control: Based on the final q-axis current command and excitation current command Id, the required d-axis and q-axis voltages are calculated by a current regulator (such as a PI controller), and then generated by PARK inverse conversion and SVPWM modulation to drive the motor.

[0038] Loop execution until exit mode: Repeat the above steps in each control cycle until the vehicle controller issues a command to exit the parking heating mode (e.g., the temperature reaches the target, the vehicle intends to drive, etc.). At this time, the active damping control module is turned off and the q-axis command is reset to 0.

[0039] Key technical details and principle analysis are introduced below: 1. Active damping mechanism for suppressing jitter: During shutdown heating, due to the tooth flank backlash, the rotor will oscillate freely within the backlash under slight disturbances. This oscillation can be considered as an underdamped second-order mechanical system. When a damping torque proportional to the rotational speed is applied... Tdamp = Kp · oh Then, the mechanical equations of motion of the system become:

[0040] Summarized as follows:

[0041] Where J is the moment of inertia and B is the original mechanical damping coefficient. This represents the load torque (including friction, etc.). It can be seen that by introducing... Kp The system's equivalent damping coefficient increases from B to B+. Kp The damping ratio is significantly improved, thereby rapidly damping the oscillation and quickly stabilizing the rotor at the tooth surface contact position.

[0042] 2. Parameters Kp Calibration method: Kp The magnitude of the vibration damping effect and system stability are directly affected. Kp If the value is too small, the damping will be insufficient; if it is too large, it may introduce noise amplification or cause current saturation. The following calibration procedure is recommended: Simulate the load (including gaps) of a real vehicle on a test bench and run the parking heating mode.

[0043] Gradually increase Kp The value is used to monitor the speed fluctuation amplitude and q-axis current response.

[0044] Select the option that minimizes speed fluctuations (e.g., less than ±5 rpm) and prevents significant oscillations in the q-axis current. Kp The value is used as the final calibration value.

[0045] It can be calibrated separately for different motors / vehicle platforms and stored in the controller.

[0046] 3. The necessity of the filtering stage: Without filtering, high-frequency noise in the speed signal (such as components near the switching frequency) will be amplified by the proportional controller, generating high-frequency torque ripple, which may cause additional vibration or losses. Therefore, adding a low-pass filter is the preferred solution, with a cutoff frequency higher than the dominant frequency of speed fluctuations (usually a few Hz to tens of Hz) and lower than the electrical noise frequency.

[0047] 4. Compatibility with existing control systems: This disclosure superimposes the current loop outside the existing current loop without altering the internal current regulator structure. The excitation current Id remains at its original setting, therefore the heating power is unaffected. The average value of the damping torque is zero, so no average torque is generated, thus it does not affect zero-speed holding.

[0048] like Figure 3 As shown, the speed pulsation suppression system based on active damping includes: The parking heating start unit 301, the speed signal acquisition unit 302, the active damping torque calculation unit 303, the q-axis current command calculation unit 304, and the suppression control unit 305 are included. The parking heating start unit 301 is used to acquire vehicle status signals and control the motor to enter the parking heating mode when the parking heating conditions are met. The speed signal acquisition unit 302 is used to set the initial q-axis current command, give the d-axis excitation current command for generating heat in the parking heating mode, and acquire the real-time speed signal of the motor rotor. The active damping torque calculation unit 303 calculates the active damping torque for suppressing rotor oscillation based on the real-time speed signal and through a damping control algorithm. The direction of the active damping torque is opposite to the direction of rotor rotation. The q-axis current command calculation unit 304 is used to substitute the active damping torque and the d-axis excitation current command into the torque formula to calculate the final q-axis current command. The suppression control unit 305 is used to control the motor according to the d-axis excitation current command and the final q-axis current command to suppress the rotor oscillation near zero position caused by the tooth backlash of the transmission system.

[0049] Compared with the prior art, this disclosure has the following innovative features: First, in terms of control strategy, this disclosure breaks through the traditional parking heating mode that only applies excitation current and introduces an active damping mechanism based on speed feedback for the first time. By converting the speed fluctuation signal into reverse damping torque in real time and injecting it into the q-axis current closed loop, the active suppression of mechanical oscillation is achieved.

[0050] Secondly, in terms of physical model, this disclosure deeply analyzes the root cause of parking heating vibration, identifies the tooth backlash in the transmission system as the key factor causing the speed to fluctuate at zero speed, and proposes an active damping scheme that directly addresses the essence of the problem, eliminating the back-and-forth oscillation within the backlash from the root cause.

[0051] Furthermore, in terms of implementation, this solution is entirely based on software algorithms, requiring no additional hardware costs. It only requires embedding an active damping control module into the existing motor controller, offering advantages such as short development cycle, strong portability, and ease of engineering.

[0052] Finally, in terms of parameter design, the active damping coefficient Kp is designed based on classical control theory, with a clear physical meaning. It can be quickly calibrated through a simple bench sweep frequency experiment, avoiding the complex trade-off process in traditional PI parameter adjustment.

[0053] Compared with the prior art, this disclosure has the following beneficial effects: First, engine speed fluctuations are significantly suppressed, resulting in a substantial improvement in overall vehicle smoothness. Experimental data shows that after adopting the solution disclosed in this paper, the engine speed fluctuation amplitude in parking heating mode is reduced from more than ±50 rpm to within ±5 rpm, and the vehicle vibration phenomenon is completely eliminated.

[0054] Secondly, it does not affect the original heating function, and the heating power remains unchanged. The active damping torque is a dynamic compensation amount with an average value of zero, which will not increase the additional effective value of the q-axis current. While suppressing vibration, it ensures that the battery heating or cabin heating effect is not affected in any way.

[0055] Third, it requires no hardware modifications, resulting in a significant cost advantage. This solution is a pure software algorithm that can be directly applied to the controllers of existing mass-produced vehicles without changing the hardware design or increasing material costs, offering extremely high cost-effectiveness and widespread application value.

[0056] Fourth, parameter calibration is simple and highly adaptable. The physical meaning of the active damping coefficient Kp is clear, the calibration process is simple and quick, and it is highly adaptable to different motor parameters and different vehicle platforms, significantly shortening the development cycle.

[0057] Fifth, improve system stability and avoid control misjudgments. By suppressing speed fluctuations, problems such as speed over-limit and repeated mode switching caused by zero-crossing fluctuations are avoided, thus improving the stability and reliability of the vehicle control system.

[0058] like Figure 4 As shown, this disclosure provides an electronic device, including a processor 401, a communication interface 402, a memory 403, and a communication bus 404, wherein the processor 401, the communication interface 402, and the memory 403 communicate with each other through the communication bus 404. Memory 403 stores computer programs; The processor 401 implements the above method when executing a computer program stored in the memory 403.

[0059] This disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0060] The computer-readable storage medium may be included in the device / apparatus described in the above embodiments; or it may exist independently and not assembled into the device / apparatus. The computer-readable storage medium carries one or more programs that, when executed, implement the method according to the embodiments of this disclosure.

[0061] According to embodiments of this disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0062] An electric vehicle includes the aforementioned motor controller.

[0063] Although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for suppressing rotational speed pulsation based on active damping, characterized in that, include: The system acquires vehicle status signals and controls the motor to enter parking heating mode when the parking heating conditions are met. In the parking heating mode, set the initial q-axis current command, give the d-axis excitation current command for generating heat, and obtain the real-time speed signal of the motor rotor. Based on the real-time speed signal, the active damping torque used to suppress rotor oscillation is calculated through a damping control algorithm. The direction of the active damping torque is opposite to the direction of rotor rotation. Substituting the active damping torque and d-axis excitation current command into the torque formula, the final q-axis current command is calculated. The motor is controlled according to the d-axis excitation current command and the final q-axis current command to suppress rotor oscillation near zero position caused by backlash in the transmission system.

2. The method for suppressing speed pulsation based on active damping as described in claim 1, characterized in that, When the parking heating conditions are met, the control motor enters the parking heating mode, including: When the vehicle controller detects that the ambient temperature is lower than the preset threshold, the vehicle is stationary, and the vehicle safety is met, it sends a command to the motor controller to enter the active parking heating mode.

3. The method for suppressing speed pulsation based on active damping as described in claim 1, characterized in that, Based on the real-time speed signal, the active damping torque used to suppress rotor oscillation is calculated through a damping control algorithm, including: Calculate the active damping torque using the following formula: Tdamp ( k ) = Kp · ω ( k ) in, Tdamp ( k () represents the active damping torque in the k-th period. Kp This is the active damping coefficient. ω ( k () represents the real-time speed signal, and the negative sign indicates that the direction of the active damping torque is opposite to the direction of the speed.

4. The method for suppressing speed pulsation based on active damping as described in claim 1, characterized in that, Based on the real-time speed signal, the active damping torque used to suppress rotor oscillation is calculated through a damping control algorithm, including: The real-time speed signal is filtered to remove high-frequency noise and obtain the filtered speed signal. Calculate the active damping torque using the following formula: Tdamp ( k ) = Kp · ωf ( k ) in, Tdamp ( k () represents the active damping torque with period k. Kp This is the active damping coefficient. ωf ( k ) represents the speed signal after k-cycle filtering, and the negative sign indicates that the direction of the active damping torque is opposite to the direction of the speed.

5. The method for suppressing speed pulsation based on active damping as described in claim 4, characterized in that, The real-time speed signal is filtered using a first-order low-pass filter algorithm, the discrete expression of which is as follows: ωf ( k )= α · ω ( k )+(1 α )· ωf ( k 1) in, ω ( k () represents the real-time rotational speed signal with k periods. ωf ( k 1) is the filtered rotational speed signal with a period of k-1, where α is the filtering coefficient, which is determined by the sampling period and the cutoff frequency.

6. The method for suppressing rotational speed pulsation based on active damping as described in claim 3 or 4, characterized in that, Active damping coefficient Kp The methods for determining this include: The parking heating mode was operated in a bench environment that included the backlash of the transmission system teeth. Gradually adjust the active damping coefficient Kp The value; Monitor the amplitude of motor speed fluctuations and the q-axis current response; Select a value that ensures the speed fluctuation amplitude is less than a preset threshold and that the q-axis current does not oscillate. Kp The value is used as the final calibration value.

7. The method for suppressing speed pulsation based on active damping as described in claim 1, characterized in that, It also includes exit control steps: Real-time monitoring of ambient temperature, battery temperature, or vehicle status; When the temperature reaches the preset target value, or when a signal indicating the vehicle's intention to drive is received, the motor is controlled to exit the parking heating mode. When exiting the parking heating mode, the active damping torque is set to zero, and the q-axis current command is reset to 0.

8. A speed pulsation suppression system based on active damping, characterized in that, include: Parking heating start unit, speed signal acquisition unit, active damping torque calculation unit, q-axis current command calculation unit, and suppression control unit; The parking heating start unit is used to acquire vehicle status signals and control the motor to enter the parking heating mode when the parking heating conditions are met. The speed signal acquisition unit is used to set the initial q-axis current command, give the d-axis excitation current command for generating heat, and acquire the real-time speed signal of the motor rotor in the parking heating mode. The active damping torque calculation unit calculates the active damping torque used to suppress rotor oscillation based on the real-time speed signal and through a damping control algorithm. The direction of the active damping torque is opposite to the direction of rotor rotation. The q-axis current command calculation unit is used to substitute the active damping torque and the d-axis excitation current command into the torque formula to calculate the final q-axis current command. The suppression control unit is used to control the motor according to the d-axis excitation current command and the final q-axis current command to suppress rotor oscillation near zero position caused by backlash in the transmission system.

9. A motor controller, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, which stores computer programs; When a processor executes a computer program stored in a memory, it implements the active damping-based speed pulsation suppression method according to any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the speed pulsation suppression method based on active damping as described in any one of claims 1-7.

11. An electric vehicle, characterized in that, Includes the motor controller as described in claim 9.

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