Steering wheel tremor suppression motor torque control method and system and vehicle

Abstract

The invention discloses a steering wheel tremor suppression motor torque control method and system and a vehicle, and relates to the technical field of vehicle EPS control, and the method comprises the steps that the vehicle speed, the steering wheel torque, the rotating speed and the rotating angle signal in the vehicle driving process are obtained in real time; the real-time vehicle speed, the steering wheel rotating speed and the steering wheel turning angle signal are compared with a set threshold value, and whether the tremor suppression condition is met or not is judged; if yes, performing time-frequency domain conversion on the steering wheel torque signal by using fast Fourier transform, adaptively extracting a time domain torque signal corresponding to a tremor frequency band, calculating a reverse compensation torque according to the time domain torque signal, outputting the reverse compensation torque after limit value processing, and controlling a motor to perform torque compensation on the steering wheel torque; and if not, torque compensation is not carried out. According to the method, the vibration frequency of the steering wheel can be recognized more accurately, the more accurate compensation torque can be obtained through calculation, the control efficiency, precision and robustness are improved, and the control safety is improved through judgment of the vibration suppression condition and an amplitude limiting strategy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle EPS control, and in particular to a steering wheel shake suppression motor torque control method and system and a vehicle. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The automobile steering system has gone through five development stages in turn, namely, mechanical steering system (MS), hydraulic power steering system (HPS), electric hydraulic power steering system (EHPS), electric power steering system (EPS), and steer-by-wire system (SBW). The current electric power steering system (EPS) is the mainstream steering system solution for passenger cars. Compared with the traditional hydraulic steering system, the EPS not only has many advantages such as energy saving and environmental protection, high efficiency, good controllability, precise control, and special functions such as road shock suppression, but also brings better driving experience to the driver. Among them, the EPS system can detect the steering wheel vibration or shaking caused by the uneven road with the help of the torque sensor, and suppress the shaking of the steering wheel by controlling the motor to output a reverse torque, thereby improving the driving comfort.

[0004] For road or steering wheel shake suppression, when the EPS system is working, the steering wheel torque signal is monitored in real time by the torque sensor, the vibration signal of a specific frequency is identified and separated by using a filtering algorithm such as a low-pass or band-pass filter, and a reverse torque is output by the motor according to the vibration characteristics, thereby reducing the shaking of the steering wheel. However, the existing EPS system still has some problems when suppressing road shaking: (1) Robustness: When the extreme road conditions (such as continuous deceleration strips) or the vehicle load changes, high-frequency vibration will be generated, which will increase the noise of the sensor signal. The signal processing algorithm used by the existing EPS system is mostly low-pass / band-pass filtering, which may introduce phase delay when processing the steering wheel torque signal with high noise, and thus may easily cause insufficient compensation or excessive suppression.

[0005] (2) Safety: Considering that excessive suppression of shaking may interfere with the basic assistance function, causing steering delay or loss of control, accurate calculation of the reverse torque according to the vibration characteristics and avoidance of excessive suppression are important prerequisites for ensuring driving safety. However, the filtering and calculation processing of the existing EPS system are not accurate, which cannot avoid excessive suppression and affect driving safety.

[0006] (3) Real-time: Road shock suppression requires that the algorithm completes calculation and execution within milliseconds, and the calculation efficiency of the existing algorithm still needs to be improved. SUMMARY

[0007] To solve the above problems of the prior art, the application provides a steering wheel vibration suppression motor torque control method, system and vehicle, which can more accurately identify the vibration frequency of the steering wheel by using fast Fourier transform for time-frequency domain conversion and vibration frequency band torque signal extraction, calculate more accurate compensation torque, improve the efficiency, accuracy and robustness of control, and improve the safety of control through vibration suppression condition determination and amplitude limiting strategy, thereby solving the problems of unsatisfactory steering wheel vibration suppression effect, low control accuracy and insufficient robustness of the existing EPS system.

[0008] In a first aspect, the application provides a steering wheel vibration suppression motor torque control method.

[0009] A steering wheel vibration suppression motor torque control method comprises the following steps: Real-time acquisition of vehicle speed, steering wheel torque, steering wheel speed and steering wheel angle signals during vehicle driving; Comparison of real-time vehicle speed, steering wheel speed, steering wheel angle signals with set threshold values to determine whether the vibration suppression condition is met; If the condition is met, fast Fourier transform is used for time-frequency domain conversion of the steering wheel torque signal, and the time domain torque signal corresponding to the vibration frequency band is adaptively extracted, then the reverse compensation torque is calculated according to the time domain torque signal, and the compensation torque is output after limiting value processing, so that the motor controls the torque compensation of the steering wheel torque; if the condition is not met, no torque compensation is performed.

[0010] In a further technical solution, the condition for triggering vibration suppression is: According to the low-speed working condition of real vehicle calibration, the vehicle speed threshold is determined to determine whether the real-time vehicle speed is less than the vehicle speed threshold; According to the active steering working condition of real vehicle calibration, the steering wheel speed and steering wheel angle threshold values are determined to determine whether the real-time steering wheel speed and steering wheel angle are greater than the real-time steering wheel speed and steering wheel angle threshold values; If the vehicle speed, steering wheel speed and steering wheel angle all meet the corresponding judgment conditions, it is determined that the vibration suppression condition is met, and the vibration suppression function is started; otherwise, the vibration suppression compensation torque is controlled to be 0.

[0011] In a further technical solution, the fast Fourier transform is used for time-frequency domain conversion of the steering wheel torque signal, and the time domain torque signal corresponding to the vibration frequency band is adaptively extracted, which comprises the following steps: Fast Fourier transform is performed on the steering wheel torque signal to obtain the frequency domain torque signal; Based on the frequency domain torque signal, the torque signal corresponding to the vibration frequency band is adaptively extracted; The extracted torque signal is converted into a time domain torque signal by using inverse fast Fourier transform; the time domain torque signal is a time domain vibration torque signal.

[0012] Further technical solutions, the determination of the tremor frequency band comprises: The vehicle load state is identified by using the vehicle-mounted air spring pressure sensor, and a pre-established tremor frequency band-load relationship mapping table is combined to dynamically adjust the tremor frequency band range according to the vehicle load state, so as to determine the tremor frequency band corresponding to the current vehicle load state.

[0013] Further technical solutions, the limit value processing is: If the calculated reverse compensation torque is greater than the maximum compensation torque, the maximum compensation torque is output; otherwise, if the calculated reverse compensation torque is not greater than the maximum compensation torque, the calculated reverse compensation torque is output.

[0014] In a second aspect, the present application provides a steering wheel tremor suppression motor torque control system.

[0015] A steering wheel tremor suppression motor torque control system comprises: A signal acquisition module is configured to acquire the vehicle speed, steering wheel torque, steering wheel speed and steering wheel angle signals in real time during vehicle driving; A torque control module is configured to compare the real-time vehicle speed, steering wheel speed, steering wheel angle signals with the set threshold value to determine whether the tremor suppression condition is met; if so, the steering wheel torque signal is converted from time domain to frequency domain by using fast Fourier transform, the time domain torque signal corresponding to the tremor frequency band is adaptively extracted, the reverse compensation torque is calculated according to the time domain torque signal, and the compensation torque is output after limit value processing, so as to control the motor to compensate the steering wheel torque; if not, no torque compensation is performed.

[0016] Further technical solutions, the condition for triggering tremor suppression is: According to the low-speed working condition calibrated by the real vehicle, the vehicle speed threshold value is determined to judge whether the real-time vehicle speed is less than the vehicle speed threshold value; According to the active steering working condition calibrated by the real vehicle, the steering wheel speed and steering wheel angle threshold values are determined to judge whether the real-time steering wheel speed and steering wheel angle are greater than the real-time steering wheel speed and steering wheel angle threshold values; If the vehicle speed, steering wheel speed and steering wheel angle all meet the corresponding judgment conditions, it is determined that the tremor suppression condition is met, and the tremor suppression function is started; otherwise, the tremor suppression compensation torque is controlled to be 0.

[0017] Further technical solutions, the steering wheel torque signal is converted from time domain to frequency domain by using fast Fourier transform, and the time domain torque signal corresponding to the tremor frequency band is adaptively extracted, comprising: The steering wheel torque signal is subjected to fast Fourier transform to obtain the frequency domain torque signal; Based on the frequency domain torque signal, the torque signal corresponding to the tremor frequency band is adaptively extracted; The extracted torque signal is converted into a time domain torque signal by using an inverse fast Fourier transform.

[0018] Further technical solutions, the determination of the tremor frequency band comprises: The vehicle load state is identified by using the vehicle-mounted air spring pressure sensor, and the tremor frequency band range is dynamically adjusted according to the vehicle load state by combining the pre-established tremor frequency band-load relationship mapping table, so that the tremor frequency band corresponding to the current vehicle load state is determined.

[0019] In a third aspect, the present application also provides a vehicle.

[0020] A vehicle comprises the steering wheel tremor suppression motor torque control system of the second aspect, or implements the steering wheel tremor suppression motor torque control method of the first aspect.

[0021] The above one or more technical solutions have the following beneficial effects: 1. The present application provides a steering wheel tremor suppression motor torque control method, system and vehicle, which can more accurately identify the vibration frequency of the steering wheel by using fast Fourier transform for time-frequency domain conversion and tremor frequency band torque signal extraction, calculate more accurate compensation torque, improve the efficiency, accuracy and robustness of control, and improve the safety of control through the determination of tremor suppression conditions and the limiting strategy, solving the problems of unsatisfactory steering wheel tremor suppression effect, low control accuracy and insufficient robustness of the existing EPS system.

[0022] 2. In the present application, it is first determined whether the tremor suppression is met, and then the torque compensation calculation is performed according to the steering wheel torque signal when it is met, which can effectively prevent the situation that the tremor suppression is mistakenly triggered and interferes with the driver's operation, avoid the situation that the system mistakenly judges the artificial steering torque as road tremor, eliminate the risk of "stealing the steering wheel" caused by sudden change of steering force, avoid the risk of losing control at low speed, avoid the situation that the suppression torque interferes with the stability of the vehicle at high speed, and effectively reduce the invalid action of the motor and avoid invalid compensation.

[0023] 3. Compared with the limited filtering frequency band precision of direct time domain filtering, the present application can more accurately identify the vibration frequency of the steering wheel by using the fast Fourier transform FFT algorithm, improve the accuracy of control and the robustness of the system, and effectively improve the safety of control by introducing the determination of suppression conditions and the limiting strategy, which can effectively avoid excessive suppression and ensure driving safety.

[0024] The advantages of the additional aspects of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The embodiments of the application, and their

[0026] Figure 1 The overall flow chart of the steering wheel shake suppression motor torque control method according to the embodiment of the application is shown in the figure. Figure 2 The schematic diagram of a set of steering wheel torque signals filtered by FFT to extract the shake frequency band signal according to the embodiment of the application is shown in the figure. a ) is the original signal, and ( b ) is the filtered signal. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed description is exemplary only and is intended to provide further description of the specific embodiments in order to provide a further understanding of the application, and is not intended to limit the exemplary embodiments according to the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they refer to the presence of a feature, step, operation, device, component, and / or combinations thereof.

[0028] Embodiment One In view of the problems of the existing EPS system, such as unsatisfactory steering wheel shake suppression effect, low control precision, and insufficient robustness, the present embodiment provides a steering wheel shake suppression motor torque control method, as shown in the figure, which comprises the following steps: Figure 1 Step S1, real-time acquisition of vehicle speed, steering wheel torque, steering wheel speed, and steering wheel angle signals during vehicle driving.

[0029] Specifically, during vehicle driving, the vehicle speed signal is acquired through the vehicle CAN signal, and the steering wheel torque, steering wheel speed, and steering wheel angle signals are acquired through the steering wheel torque and angle sensors.

[0030] Step S2, comparison of the real-time vehicle speed, steering wheel speed, and steering wheel angle signals with the set threshold value to determine whether the shake suppression condition is met.

[0031] Specifically, the conditions for triggering the road surface shake suppression are set in advance, including: (1) According to the low-speed working condition of the real vehicle calibration, the vehicle speed threshold value is determined to judge whether the real-time vehicle speed is less than the vehicle speed threshold value; wherein the vehicle speed threshold value is set to be adjustable in the range of 10-20 km / h.

[0032] ​(2) According to the active steering working condition of real vehicle calibration, the steering wheel speed and the steering wheel angle threshold are determined, and it is judged whether the real-time steering wheel speed and the steering wheel angle are greater than the real-time steering wheel speed and the steering wheel angle threshold; wherein the steering wheel speed threshold is set to 30-70 deg / s adjustable range, and the steering wheel angle threshold is set to 60-120 deg adjustable range.

[0033] (3) If the vehicle speed, steering wheel speed and steering wheel angle all meet the corresponding judgment conditions, it is judged that the vibration suppression condition is met, and the vibration suppression function is started; otherwise, the vibration suppression compensation torque is controlled to be 0.

[0034] In this embodiment, the thresholds of vehicle speed, steering wheel speed and steering wheel angle are determined according to the real vehicle calibration, including: (1) The vehicle speed threshold is set to 15km / h, when the real-time vehicle speed is less than the set vehicle speed threshold, it is in the low-speed driving state at this time, the driver is sensitive to the steering feel at low speed, and the road excitation frequency is low, by limiting the vehicle speed to be less than the threshold to ensure that the low-speed sensitive working condition cannot trigger the vibration suppression; (2) The steering wheel speed threshold is set to 50 deg / s, when the real-time steering wheel speed is greater than the set steering wheel speed threshold, it means that the driver is active steering at this time, and the vibration suppression function can be closed; (3) The steering wheel angle threshold is set to 90 deg, when the absolute value of the real-time steering wheel angle is greater than the steering wheel angle threshold, it means that the driver is active steering at this time, and the vibration suppression function can be closed; When any signal meets the above conditions, the road vibration suppression function is closed, and the vibration suppression compensation torque output is 0 at this time.

[0035] Through the above-mentioned way of first judging whether the vibration suppression is met, and then performing the next step of torque compensation calculation according to the steering torque signal, this way can effectively prevent the vibration suppression from being triggered by mistake and interfering with the driver's operation, avoid the system from misjudging the human steering torque as road vibration, eliminate the risk of "stealing the steering wheel" caused by sudden change of steering force, avoid the risk of losing control at low speed, avoid the situation that the suppression torque interferes with the stability of the vehicle at high speed, and effectively reduce the invalid action of the motor and avoid invalid compensation.

[0036] Step S3, if it is met, the steering torque signal is converted from time domain to frequency domain by using fast Fourier transform, the time domain torque signal corresponding to the vibration frequency band is adaptively extracted, and then the reverse compensation torque is calculated according to the time domain torque signal, and after limit processing, it is output, and the motor is controlled to compensate the steering torque; if it is not met, no torque compensation is performed.

[0037] Step S3.1, when the tremor suppression condition is met, start the tremor suppression function. First, the steering wheel torque signal is subjected to a fast Fourier transform (FFT) to obtain a frequency domain torque signal, the torque signal corresponding to the tremor frequency band is adaptively extracted, and the extracted torque signal is converted into a time domain torque signal using an inverse fast Fourier transform, which is the time domain tremor torque signal.

[0038] Specifically, the fast Fourier transform is improved based on the discrete Fourier transform (DFT), wherein the discrete Fourier transform can be represented as: ; The matrix expression is: ; In the above formula, is the n th sampling point of the time domain signal; is the k th calculation result of the frequency domain signal; N is the total number of sampling points; k is the frequency index, taking a value from 0 to N-1; is a complex exponential function (i.e., a rotation factor), represents the value of the complex exponential function with a frequency of n at k , and the calculation complexity of the DFT is .

[0039] Further, using the property of the complex exponential function (i.e., the rotation factor), (symmetry), the operation efficiency of the DFT can be improved, and the calculation complexity is optimized to , i.e., the fast Fourier transform FFT.

[0040] The fast Fourier transform FFT is used to transform the steering wheel torque signal from the time domain to the frequency domain, including the following 3 steps: (1) Decompose the signal, and divide the sampled steering wheel torque signal according to the index into even and odd parts, such as for the signal , which can be decomposed as: Even part: ; Odd part: ; Then ; Wherein: ; Wherein, ; ; Wherein, ; ; wherein, ; ; wherein, ; ; wherein, ; The DFT result of N points can be obtained by the above calculation, which can be calculated by the DFT results of two N / 2 point odd and even inputs.

[0041] (2) Recursive call, continue to decompose the DFT of N / 2 points, until the decomposition is the DFT of 2 points, and finally the calculation complexity can be reduced from to , which can be represented as: ; ;

[0042] (3) Merge the results, merge the FFT results of the even and odd parts to get the final frequency domain signal. In this embodiment, the signal waveforms before and after the fast Fourier transform processing are shown in Figure 2 .

[0043] After that, the torque signal corresponding to the tremor frequency band is adaptively extracted from the frequency domain torque signal obtained above. Generally, the tremor frequency band is a fixed frequency band, which is often calibrated according to the actual vehicle performance, and is usually set to 8-30Hz. However, considering that the fixed frequency band (8-30Hz) cannot adapt to vehicles with different axle loads, such as a difference of ±5Hz in the empty / full load tremor frequency, in order to ensure that the subsequent calculation of the reverse torque compensation value based on the tremor frequency band torque signal is more accurate, in this embodiment, the vehicle load state is identified by using the on-board air spring pressure sensor, and a pre-established tremor frequency band-load relationship mapping table is combined to dynamically adjust the tremor frequency band range according to the vehicle load state, to determine the tremor frequency band corresponding to the current vehicle load state, and on this basis, the torque signal of the corresponding tremor frequency band is extracted.

[0044] Finally, after extracting the tremor frequency band torque signal, inverse fast Fourier transform IFFT is performed on it to transform the frequency domain signal into a time domain signal. IFFT can be realized by FFT, and the conjugate of the frequency domain signal is taken, the FFT is performed on the conjugate signal, and the conjugate is taken again and normalized, which can be represented as: .

[0045] Compared with the limited filtering band precision of direct time domain filtering, the embodiment can more accurately identify the steering wheel vibration frequency through the fast Fourier transform (FFT) algorithm, thereby improving the control precision and system robustness.

[0046] Step S3.2. Calculate the reverse compensation torque according to the time domain torque signal, perform limit value processing, and output the control motor to compensate the steering wheel torque.

[0047] Specifically, after obtaining the steering wheel tremor time domain torque signal, the reverse torque compensation is calculated according to the signal, that is, the time domain torque signal is divided by the transmission ratio of the EPS system transmission mechanism , multiplied by -1, and the motor compensation torque value (i.e., the reverse compensation torque) is obtained, which can be expressed as: .

[0048] Further, the motor compensation torque value calculated above is subjected to limit value processing, that is, if the calculated reverse compensation torque is greater than the maximum compensation torque, the maximum compensation torque is output; otherwise, if the calculated reverse compensation torque is not greater than the maximum compensation torque, the calculated reverse compensation torque is output.

[0049] In the embodiment, the maximum compensation torque is limited, which is limited to: the absolute value of the tremor suppression torque is not more than 30% of the basic boost torque, which can be expressed as: ; wherein, is the compensation torque, is the basic boost torque.

[0050] Through the determination of the suppression condition and the limiting strategy, the safety of the control can be effectively improved, and the over-suppression situation can be effectively avoided to ensure the driving safety.

[0051] Step S3.3. If the tremor suppression condition is not met, the tremor suppression function is not started, and the torque compensation is not performed, that is, the output compensation torque is 0.

[0052] Based on the above method, the embodiment can more accurately identify the steering wheel vibration frequency through the time-frequency domain conversion and tremor frequency band torque signal extraction by using the fast Fourier transform, calculate more accurate compensation torque, improve the efficiency, precision and robustness of the control, and improve the safety of the control through the determination of the tremor suppression condition and the limiting strategy, thereby solving the problems of the existing EPS system, such as the unsatisfactory steering wheel tremor suppression effect, low control precision, and insufficient robustness.

[0053] Embodiment Two The embodiment provides a steering wheel tremor suppression motor torque control system, which comprises: a signal acquisition module, configured to acquire a vehicle speed and steering wheel torque, speed and angle signals in real time during vehicle driving; a torque control module, configured to compare the real-time vehicle speed, steering wheel speed and steering wheel angle signals with set threshold values, to determine whether the tremor suppression condition is met; if so, to perform time-frequency domain conversion on the steering wheel torque signal using fast Fourier transform, to adaptively extract the time-domain torque signal corresponding to the tremor frequency band, to calculate the reverse compensation torque according to the time-domain torque signal, to perform limit value processing, and to output the limit value processed torque signal to control the motor to compensate the steering wheel torque; if not, to not perform torque compensation.

[0054] Further, the condition for triggering tremor suppression is that: according to the low-speed working condition calibrated by the real vehicle, the vehicle speed threshold value is determined to determine whether the real-time vehicle speed is less than the vehicle speed threshold value; according to the active steering working condition calibrated by the real vehicle, the steering wheel speed and angle threshold values are determined to determine whether the real-time steering wheel speed and angle are greater than the real-time steering wheel speed and angle threshold values; if the vehicle speed, steering wheel speed and steering wheel angle all meet the corresponding determination conditions, it is determined that the tremor suppression condition is met, and the tremor suppression function is started; otherwise, the tremor suppression compensation torque is controlled to be 0.

[0055] Further, the time-frequency domain conversion on the steering wheel torque signal using fast Fourier transform, adaptively extracting the time-domain torque signal corresponding to the tremor frequency band, includes: performing fast Fourier transform on the steering wheel torque signal to obtain a frequency domain torque signal; adaptively extracting the torque signal corresponding to the tremor frequency band based on the frequency domain torque signal; converting the extracted torque signal into a time-domain torque signal using inverse fast Fourier transform; the time-domain torque signal is a time-domain tremor torque signal.

[0056] Further, the determination of the above-mentioned tremor frequency band includes: identifying the vehicle load state using the vehicle-mounted air spring pressure sensor, combining the pre-established tremor frequency band-load relationship mapping table, dynamically adjusting the tremor frequency band range according to the vehicle load state, and determining the tremor frequency band corresponding to the current vehicle load state.

[0057] Further, the limit value processing is: if the calculated reverse compensation torque is greater than the maximum compensation torque, the maximum compensation torque is output; otherwise, if the calculated reverse compensation torque is not greater than the maximum compensation torque, the calculated reverse compensation torque is output.

[0058] Embodiment three The embodiment provides a vehicle including the steering wheel tremor suppression motor torque control system proposed in embodiment two, or implementing the steering wheel tremor suppression motor torque control method proposed in embodiment one.

[0059] The steps involved in the above embodiments 2 to 3 correspond to the method of embodiment 1, and the specific implementation can refer to the relevant description part of embodiment 1.

[0060] The above only describes the preferred embodiments of the present application, and the specific embodiments of the present application are described in conjunction with the drawings, but are not a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications or changes made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. A steering wheel vibration suppression motor torque control method, characterized in that: include: Real-time acquisition of vehicle speed, steering wheel torque, speed and angle signals during driving; Compare the real-time vehicle speed, steering wheel speed, and steering wheel angle signals with the set thresholds to determine whether the tremor suppression conditions are met; If the conditions are met, the steering wheel torque signal is converted into the time-frequency domain using fast Fourier transform, and the time-domain torque signal corresponding to the vibration frequency band is adaptively extracted. The reverse compensation torque is then calculated based on the time-domain torque signal, and the output is processed by limiting the value to control the motor to compensate for the steering wheel torque. If not satisfied, no torque compensation is performed.

2. The steering wheel vibration suppression motor torque control method according to claim 1, characterized in that: The conditions for triggering tremor suppression are: Determine the vehicle speed threshold based on the low-speed operating condition calibrated by the actual vehicle, and judge whether the real-time vehicle speed is less than the vehicle speed threshold; Determine the steering wheel speed and angle thresholds based on the active steering working conditions calibrated by the actual vehicle, and judge whether the real-time steering wheel speed and angle are greater than the real-time steering wheel speed and angle thresholds; If the vehicle speed, steering wheel speed, and steering wheel angle all meet the corresponding judgment conditions, it is determined that the tremor suppression conditions are met and the tremor suppression function is activated; otherwise, the tremor suppression compensation torque is controlled to 0.

3. The steering wheel vibration suppression motor torque control method according to claim 1, characterized in that: The steering wheel torque signal is converted into the time-frequency domain using fast Fourier transform, and the time-domain torque signal corresponding to the vibration frequency band is adaptively extracted, including: Perform fast Fourier transform on the steering wheel torque signal to obtain the frequency domain torque signal; Based on the frequency domain torque signal, the torque signal corresponding to the tremor frequency band is adaptively extracted; The extracted torque signal is converted into a time-domain torque signal by using inverse fast Fourier transform; the time-domain torque signal is a time-domain tremor torque signal.

4. The steering wheel vibration suppression motor torque control method according to claim 3, characterized in that: Determining the tremor frequency band includes: The vehicle load state is identified by using the on-board air spring pressure sensor. Combined with the pre-established vibration frequency band-load relationship mapping table, the vibration frequency band range is dynamically adjusted according to the vehicle load state to determine the vibration frequency band corresponding to the current vehicle load state.

5. The steering wheel vibration suppression motor torque control method according to claim 1, characterized in that: The limit processing is: If the calculated reverse compensation torque is greater than the maximum compensation torque, the maximum compensation torque is output; conversely, if the calculated reverse compensation torque is not greater than the maximum compensation torque, the calculated reverse compensation torque is output.

6. A steering wheel vibration suppression motor torque control system, characterized in that: include: The signal acquisition module is used to obtain the vehicle speed, steering wheel torque, speed and angle signals in real time during driving; The torque control module is used to compare the real-time vehicle speed, steering wheel speed, and steering wheel angle signals with the set thresholds to determine whether the vibration suppression conditions are met; If the conditions are met, the steering wheel torque signal is converted into the time-frequency domain using fast Fourier transform, and the time-domain torque signal corresponding to the vibration frequency band is adaptively extracted. The reverse compensation torque is then calculated based on the time-domain torque signal, and the output is processed by limiting the value to control the motor to compensate for the steering wheel torque. If not satisfied, no torque compensation is performed.

7. The steering wheel vibration suppression motor torque control system according to claim 6, characterized in that: The conditions for triggering tremor suppression are: Determine the vehicle speed threshold based on the low-speed operating condition calibrated by the actual vehicle, and judge whether the real-time vehicle speed is less than the vehicle speed threshold; Determine the steering wheel speed and angle thresholds based on the active steering working conditions calibrated by the actual vehicle, and judge whether the real-time steering wheel speed and angle are greater than the real-time steering wheel speed and angle thresholds; If the vehicle speed, steering wheel speed, and steering wheel angle all meet the corresponding judgment conditions, it is determined that the tremor suppression conditions are met and the tremor suppression function is activated; otherwise, the tremor suppression compensation torque is controlled to 0.

8. The steering wheel vibration suppression motor torque control system according to claim 6, characterized in that: The steering wheel torque signal is converted into the time-frequency domain using fast Fourier transform, and the time-domain torque signal corresponding to the vibration frequency band is adaptively extracted, including: Perform fast Fourier transform on the steering wheel torque signal to obtain the frequency domain torque signal; Based on the frequency domain torque signal, the torque signal corresponding to the tremor frequency band is adaptively extracted; The extracted torque signal is converted into a time-domain torque signal by using inverse fast Fourier transform; the time-domain torque signal is a time-domain tremor torque signal.

9. The steering wheel vibration suppression motor torque control system according to claim 8, characterized in that: Determining the tremor frequency band includes: The vehicle load state is identified by using the on-board air spring pressure sensor. Combined with the pre-established vibration frequency band-load relationship mapping table, the vibration frequency band range is dynamically adjusted according to the vehicle load state to determine the vibration frequency band corresponding to the current vehicle load state.

10. A vehicle, characterized in that: The invention comprises the steering wheel vibration suppression motor torque control system according to any one of claims 6 to 9, or implements the steering wheel vibration suppression motor torque control method according to any one of claims 1 to 5.

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