Method and system for suppressing high-frequency jitter of electric vehicle and storage medium

Abstract

The invention discloses a suppression method and system for high-frequency jitter of an electric vehicle and a storage medium, and the suppression method for the high-frequency jitter of the electric vehicle comprises the following steps: S1, collecting the actual rotating speed of a driving motor in real time; s2, noise separation is carried out on the actual rotating speed through an observer, and an acceleration torque estimated value containing a high-frequency disturbance component is generated; s3, performing high-pass filtering on the acceleration torque estimated value, and extracting a compensation signal related to vehicle jitter; s4, multiplying the compensation signal by a preset compensation gain to generate a compensation current value; s5, correcting the original torque current instruction according to the compensation current value to obtain a torque current instruction; and S6, controlling a driving motor to rotate according to the torque current instruction. Noise separation is carried out on the actual rotating speed through the observer technology, the acceleration torque estimated value is calculated, compensation signals related to vehicle jitter can be obtained only through one-time high-pass filtering, and therefore the driving motor is controlled, and jitter of the electric vehicle is restrained.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and particularly relates to a method, a system and a storage medium for suppressing high-frequency jitter of an electric vehicle. Background Art

[0002] During the acceleration and deceleration process of an electric vehicle, if the acceleration changes greatly, it will cause the vehicle to impact and jitter. In the control of an electric vehicle, vehicle jitter (also known as vibration or tremor) not only increases the complexity of the control system, but also makes it difficult to debug the vehicle, resulting in a more complex and time-consuming debugging process, and also affects the driving comfort. Long-term jitter will accelerate the wear of the motor and its related components, shorten the service life of the entire system, and at the same time, frequent maintenance and replacement of components will increase the maintenance cost and affect the economic benefits.

[0003] The prior art CN117183757A discloses a method for controlling jitter of an electric vehicle. By performing second-order filtering on the motor speed and calculating the speed compensation speed component according to the filtered motor speed, and then calculating the motor output torque after anti-jitter suppression, the effect of reducing jitter is achieved. However, the performance of the filter is affected by filter parameters and there is a filtering delay, which will deteriorate the performance of the controller. And it is necessary to judge whether the jitter is caused by the motor torque passing through zero through certain devices, and the application range is relatively limited, or it will increase the vehicle manufacturing cost. Summary of the Invention

[0004] In order to solve the technical problems of filtering delay and deteriorating controller performance in the prior art, the present application provides a method, a system and a storage medium for suppressing high-frequency jitter of an electric vehicle. Among them, the method for suppressing high-frequency jitter of an electric vehicle includes the following steps: S1. Real-time collect the actual speed of the drive motor; S2. Separate the noise of the actual speed signal through an observer to generate an acceleration torque estimate value including a high-frequency disturbance component; S3. Perform high-pass filtering on the acceleration torque estimate value to extract a compensation signal related to vehicle jitter; S4. Multiply the compensation signal by a preset compensation gain to generate a compensation current value; S5. Correct the original torque current command according to the compensation current value to obtain a torque current command; S6. Control the rotation of the drive motor according to the torque current command.

[0005] By using the observer technology to separate the noise of the actual speed and calculate the acceleration torque estimate value, a compensation signal related to vehicle jitter can be obtained only through one high-pass filtering, so as to control the drive motor and suppress the jitter of the electric vehicle.

[0006] Specifically, the step of separating the noise from the actual rotational speed by the observer includes: S21. The observer calculates the estimated rotational speed according to the required torque and the mathematical model of the drive motor; S22. The observer subtracts the estimated rotational speed from the actual rotational speed to generate a rotational speed error; S23. Integrate and dynamically adjust the gain of the rotational speed error to generate an estimated value of the acceleration torque including high-frequency disturbance components.

[0007] Specifically, the observer includes at least a first state variable, a second state variable, and a first input variable. The first state variable is the actual rotational speed, the second state variable is the angle of the drive motor, and the first input variable is the torque current command.

[0008] Specifically, the observer is a Luenberger observer, and the gain matrix of the Luenberger observer realizes dynamic convergence of the error through pole placement.

[0009] The Luenberger observer corrects through the mathematical model and error feedback. When all states cannot be directly obtained by sensors, the missing information is supplemented by an algorithm, reducing the system's dependence on physical sensors and achieving high-precision estimation of the system state. Specifically, the preset compensation gain is obtained by the following method: S41. Generate an initial compensation gain based on preset conditions; S42. Calculate the preset compensation gain according to the initial compensation gain, the actual rotational speed, and the estimated value of the acceleration torque.

[0010] Specifically, the preset conditions include any one or more of the following: stationary state, uniform motion state, constant load state, stable operation state under specific working conditions, start-stop stage under specific working conditions.

[0011] When the vehicle accelerates and decelerates in different initial states, the generated jitters are different. Therefore, when suppressing the jitter, the driving state of the vehicle should be considered and different initial compensation gains should be adopted.

[0012] Specifically, the original torque current command includes a quadrature-axis current command and a direct-axis current command. The compensation current value corrects the quadrature-axis current command, and the torque current command includes the corrected quadrature-axis current command and the direct-axis current command.

[0013] Specifically, the drive motor is controlled by the following steps: S61. Obtain the three-phase current feedback by the drive motor; S62. Perform Clarke transformation and Park transformation on the three-phase current to obtain the feedback quadrature-axis current and the feedback direct-axis current; S63. Correct the feedback quadrature-axis current and the feedback direct-axis current according to the corrected quadrature-axis current command and the direct-axis current command; S64. Generate the bridge arm switch signal through inverse Park transformation and PWM conditioning, and output the three-phase drive voltage.

[0014] This application also provides a system for suppressing high-frequency jitter of an electric vehicle, including a processor and a memory. The memory is used to store program codes, and the processor calls the program codes stored in the memory to execute the method according to any one of claims 1-8.

[0015] This application also provides a computer-readable storage medium, in which instructions are stored. When the instructions run on a computer, the computer is made to execute the method according to any one of claims 1-8.

[0016] Technical effects and advantages of the present invention: Utilize the observer technology to separate the noise from the actual rotational speed, and calculate the estimated value of the acceleration torque. Only through one high-pass filter can a compensation signal related to the vehicle jitter be obtained, so as to control the drive motor, suppress the jitter of the electric vehicle, reduce the compensation delay caused by filtering, improve the response speed of the compensation action, and improve the comfort of driving the electric vehicle. Description of the drawings

[0017] Figure 1 It is a schematic flowchart of the method for suppressing high-frequency jitter of the electric vehicle of the present invention. Detailed implementation manners

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] Refer to Figure 1 , the embodiments of the present invention provide a method for suppressing high-frequency jitter of an electric vehicle, including the following steps: S1. Real-time collect the actual rotational speed of the drive motor; S2. Separate the noise from the actual rotational speed through an observer to generate an estimated value of the acceleration torque including a high-frequency disturbance component; S3. Perform high-pass filtering on the estimated value of the acceleration torque to extract a compensation signal related to the vehicle jitter; S4. Multiply the compensation signal by a preset compensation gain K to generate a compensation current value; S5. Correct the original torque current command according to the compensation current value to obtain a torque current command; S6. Control the rotation of the drive motor according to the torque current command.

[0020] Utilize the observer technology to separate the noise from the actual speed, calculate the estimated value of the acceleration torque, and obtain the compensation signal related to the vehicle jitter through only one high-pass filter, so as to control the drive motor and suppress the jitter of the electric vehicle.

[0021] Specifically, the steps of separating the noise from the actual speed by the observer include: S21. The observer calculates the estimated speed according to the required torque and the mathematical model of the drive motor; S22. The observer subtracts the estimated speed from the actual speed to generate a speed error; S23. Integrate and dynamically adjust the gain of the speed error to generate an estimated value of the acceleration torque including high-frequency disturbance components.

[0022] The observer technology is a closed-loop control method based on the system mathematical model to estimate the system state and error. Currently, commonly used observers include the Luenberger observer, the sliding mode observer, the extended state observer, etc. In this application, the Luenberger observer is adopted to estimate the operating state of the drive motor. Specifically, the Luenberger state observer of the drive motor is as follows: In the formula, A is the state matrix of the drive motor, B is the input matrix, C is the output matrix, L is the observer gain matrix, is the observed system state vector, u is the scalar control signal, and y is the scalar output signal.

[0023] The gain matrix of the Luenberger observer realizes the dynamic convergence of the error through pole placement.

[0024] The Luenberger observer, through the mathematical model and error feedback correction, when it is impossible to directly obtain all states through sensors, supplements the missing information through algorithms, reduces the system's dependence on physical sensors, and realizes high-precision estimation of the system state.

[0025] The system state vector includes at least a first state variable, a second state variable, and a first input variable. The first state variable is the actual speed of the drive motor, the second state variable is the angle of the drive motor, and the first input variable is the torque current command.

[0026] The torque current command of this application is divided into a quadrature-axis current command Iq and a direct-axis current command Id. After the vehicle-mounted system issues a demand torque command, the current distributor generates an original torque current command according to the demand torque command, including the quadrature-axis current command Iq and the direct-axis current command Id. Subsequently, the current controller controls the power devices according to these two current commands to provide three-phase electricity Ua, Ub, and Uc to the drive motor. The system then acquires the three-phase currents ia, ib, and ic, the actual rotational speed, and the rotational angle of the drive motor. The observer calculates a compensation signal according to the actual rotational speed of the drive motor, generates a compensation current value, corrects the quadrature-axis current command Iq according to the compensation current value, and the current controller controls the power devices to change the three-phase electricity Ua, Ub, and Uc according to the feedback three-phase currents, the corrected quadrature-axis current command Iq, and the direct-axis current command Id.

[0027] Specifically, it includes the following steps: S61. Obtain the three-phase currents feedback from the drive motor; S62. Perform Clarke transformation and Park transformation on the three-phase currents to obtain the feedback quadrature-axis current and the feedback direct-axis current; S63. Correct the feedback quadrature-axis current and the feedback direct-axis current according to the corrected quadrature-axis current command and the direct-axis current command; S64. Generate leg switch signals through inverse Park transformation and PWM conditioning, and output three-phase drive voltages.

[0028] When the vehicle accelerates and decelerates under different initial states, the generated jitters are not the same. Therefore, when suppressing the jitter, the driving state of the vehicle should be considered, and different initial compensation gains should be adopted.

[0029] Specifically, the preset compensation gain is obtained through the following method: S41. Generate an initial compensation gain based on preset conditions; S42. Calculate the preset compensation gain K according to the initial compensation gain, the actual rotational speed, and the estimated value of the acceleration torque.

[0030] The preset conditions include any one or more of the following: stationary state, uniform motion state, constant load state, stable operation state under specific working conditions, start-stop stage under specific working conditions.

[0031] This application also provides a system for suppressing high-frequency jitter of an electric vehicle, including a processor and a memory. The memory is used to store program codes, and the processor calls the program codes stored in the memory to execute the above method for suppressing high-frequency jitter of the electric vehicle.

[0032] The present application also provides a computer-readable storage medium. Instructions are stored in the computer-readable storage medium, and when they run on a computer, the computer is caused to execute the above-mentioned method for suppressing high-frequency jitter of an electric vehicle.

[0033] The specific implementation manners of the above system and computer-readable storage medium are all well-known technologies to those skilled in the art, and will not be elaborated herein.

[0034] Finally, the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for suppressing high-frequency jitter of an electric vehicle, characterized in that, It includes the following steps: S1. Collect the actual speed of the drive motor in real time; S2. Separate the noise of the actual speed through an observer to generate an acceleration torque estimation value including a high-frequency disturbance component; S3. Perform high-pass filtering on the acceleration torque estimation value to extract a compensation signal related to vehicle jitter; S4. Multiply the compensation signal by a preset compensation gain to generate a compensation current value; S5. Correct the original torque current command according to the compensation current value to obtain a torque current command; S6. Control the rotation of the drive motor according to the torque current command.

2. The method for suppressing high-frequency jitter of an electric vehicle according to claim 1, wherein The step of separating the noise of the actual speed through an observer includes: S21. The observer calculates an estimated speed according to the required torque and the mathematical model of the drive motor; S22. The observer subtracts the estimated speed from the actual speed to generate a speed error; S23. Integrate and dynamically adjust the gain of the speed error to generate an acceleration torque estimation value including a high-frequency disturbance component.

3. The method for suppressing high-frequency jitter of an electric vehicle according to claim 2, wherein, The observer includes at least a first state variable, a second state variable, and a first input variable. The first state variable is the actual speed, the second state variable is the angle of the drive motor, and the first input variable is the torque current command.

4. The method for suppressing high-frequency jitter of an electric vehicle according to claim 2, characterized in that, The observer is a Luenberger observer, and the gain matrix of the Luenberger observer realizes error dynamic convergence through pole placement.

5. The method for suppressing high-frequency jitter of an electric vehicle according to claim 1, characterized in that The preset compensation gain is obtained through the following method: S41. Generate an initial compensation gain based on preset conditions; S42. Calculate the preset compensation gain according to the initial compensation gain, the actual speed, and the acceleration torque estimation value.

6. The method according to claim 5, characterized in that, The preset conditions include any one or more of the following: stationary state, uniform speed state, constant load state, stable operation state under specific working conditions, start-stop stage under specific working conditions.

7. The method for suppressing high-frequency jitter of an electric vehicle according to claim 1, wherein The original torque current command includes a quadrature-axis current command and a direct-axis current command. The compensation current value corrects the quadrature-axis current command, and the torque current command includes the corrected quadrature-axis current command and the direct-axis current command.

8. The method for suppressing high-frequency jitter of an electric vehicle according to claim 7, characterized in that, The drive motor is controlled through the following steps: S61. Obtain the three-phase current fed back by the drive motor; S62. Perform Clarke transformation and Park transformation on the three-phase current to obtain a feedback quadrature-axis current and a feedback direct-axis current; S63. Correct the feedback quadrature-axis current and the feedback direct-axis current according to the corrected quadrature-axis current command and the direct-axis current command; S64. Generate a leg switch signal through inverse Park transformation and PWM conditioning and output a three-phase drive voltage.

9. A suppression system for high-frequency jitter of an electric vehicle, characterized in that, It includes a processor and a memory. The memory is used to store program codes, and the processor calls the program codes stored in the memory to execute the method according to any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, Instructions are stored in the computer-readable storage medium. When it runs on a computer, it causes the computer to execute the method according to any one of claims 1-8.

Images