A new energy commercial vehicle jitter suppression control method

Abstract

The present application relates to a kind of new energy commercial vehicle control method of inhibiting jitter, obtains motor current speed and torque;Motor current speed is filtered with two levels, and the first filter speed difference and the second filter speed difference are obtained, the first filter speed difference is weighted with the second filter speed difference, and motor target speed difference is obtained;PI adjustment module is established with motor target speed difference as input signal, and motor compensation torque is output, motor compensation torque is introduced into torque control loop, and motor current torque is added, to realize the processing of original torque, and output control torque;Low-pass filter is obtained by calibrating filter coefficient, and the first filter speed after filtering, weighting coefficient is calibrated, and the final filter speed is obtained;By observing the deviation and the amount of compensation torque, the proportional and integral coefficient is calibrated, and the final compensation torque is obtained, to realize inhibiting motor jitter, without increasing cost, algorithm is simple and wide adaptation range, solve the problem of vehicle jitter.

Description

Technical Field

[0001] This invention relates to the field of control technology for new energy commercial vehicles, and in particular to a control method for suppressing vibration in new energy commercial vehicles. Background Technology

[0002] New energy commercial vehicles are vehicles that use on-board power sources to drive the wheels with electric motors and meet all requirements of road traffic and safety regulations.

[0003] However, new energy commercial vehicles may experience torque shudder, leading to abnormal phenomena such as vehicle vibration. Based on this, prior art CN106183888A discloses a vehicle anti-shake method, system, and motor controller. However, prior art has the following problems: 1. It requires the addition of a filter, increasing costs; 2. The anti-shake logic is only implemented by the motor controller and external devices. After engineering implementation, there may be problems such as abnormal interaction between the motor, transmission, and vehicle controller, resulting in shift failure or drive abnormalities due to response delay; 3. Key parameters such as the gain coefficient lack actual vehicle calibration, and there may be discrepancies between theory and practice, making it unsuitable for practical engineering problems.

[0004] Existing technology CN113183771A discloses an anti-shake control method for an electric drive system. However, existing technology also has the following problems: 1. The estimated theoretical value of the motor has a large error and is not applicable to engineering; 2. The anti-shake logic is only implemented by the motor controller and external devices. After engineering, there may be problems such as abnormal interaction between the motor, transmission and vehicle controller, and shifting failure or drive abnormality due to response delay; 3. The speed filtering adopts a two-stage filtering superposition process. The speed obtained after the first-stage filtering is then entered into the second-stage filter, resulting in a large delay in the signal. For a system like motor control with millisecond-level changes, this solution has the risk of drive abnormality. Summary of the Invention

[0005] The purpose of this invention is to provide a control method for suppressing vibration in new energy commercial vehicles, addressing the shortcomings of existing technologies. The method involves joint control of the vehicle controller and the motor controller, followed by two-stage filtering and weighted processing to obtain the final speed difference. The weighted speed difference is then converted into torque via PI regulation. By using torque compensation as the adjustment method, the aim is to suppress motor vibration. This method does not increase costs, has a simple algorithm with a wide range of applications, and provides significant control effects, effectively solving the vehicle vibration problem.

[0006] This invention is achieved using the following technical solution:

[0007] A method for controlling vibration suppression in new energy commercial vehicles includes:

[0008] Get the current speed and torque of the motor;

[0009] Speed ​​generation filtering module: Performs two-stage filtering on the current motor speed to obtain the first-stage filtered speed difference and the second-stage filtered speed difference. The first-stage filtering is a low-pass filter and the second-stage filtering is a mean filter.

[0010] The target speed difference of the motor is obtained by weighting the speed difference between the first-level filter and the speed difference between the second-level filter.

[0011] A simulation model was built based on Matlab / Simulink. The motor speed was obtained by using the jitter speed signal recorded from the actual vehicle and performing software unit model simulation to obtain the filtering coefficients and weighting coefficients.

[0012] The weighting coefficients are set to calibration values, and the weights of the first-level filter speed difference and the second-level filter speed difference are determined by combining real vehicle data. Both the weighting coefficients and the filter coefficients have reserved calibration value interfaces for real vehicle calibration.

[0013] Torque regulation module generation: Based on PID theory, a PI regulation module is established with the target speed difference of the motor as the input signal. The output motor compensation torque is introduced into the torque control loop and added to the current torque of the motor to realize the processing of the original torque and output control torque.

[0014] Vehicle calibration: The speed of the first-stage filter after low-pass filtering is obtained by calibrating the filter coefficients. The data of the first-stage filter speed and the second-stage filter speed are analyzed, the weighting coefficients are calibrated, and the final filter speed is obtained. By observing the deviation and margin of the compensation torque, the proportional and integral coefficients are calibrated to obtain the final compensation torque.

[0015] Preferably, the first-level filtered speed difference is obtained by filtering the noise and interference at the current motor speed to get the first-level filtered speed, and then subtracting it from the current motor speed to get the first-level filtered speed difference value.

[0016] Where, the first-level filter speed = (1 - filter coefficient) × the speed filter result of the previous cycle + filter coefficient × the current motor speed;

[0017] The secondary speed difference signal is obtained by performing a 10-cycle mean filtering process on the motor speed to obtain the motor speed waveform, i.e., the secondary filtered speed. The difference between the secondary filtered speed and the current motor speed is obtained as the secondary filtered speed difference value.

[0018] Preferably, the PI control module, which uses the target speed difference of the motor as the input signal, outputs a motor compensation torque signal as follows:

[0019] Compensated torque = proportional torque + integral torque;

[0020] Wherein, the proportional torque = proportional calibration coefficient KP × motor target speed difference;

[0021] Integral torque = Integral calibration coefficient KI × Σ motor target speed difference;

[0022] When the vehicle is currently in forward gear, the drive motor rotates forward. When the target speed of the motor is greater than the actual speed of the motor, the speed difference is negative, and the compensation torque obtained after PI adjustment is negative, which is used to reduce the control torque output of the whole vehicle. When the target speed is less than the actual speed, the speed difference is positive, and the compensation torque obtained after PI adjustment is positive, which is used to increase the control torque output of the whole vehicle and suppress motor vibration.

[0023] When the vehicle is currently in reverse gear, the drive motor reverses direction. When the target speed of the motor is greater than the actual speed, the speed difference is negative, and the torque obtained after PI adjustment is negative. This negative value is then inverted to obtain a compensation torque, which is used to reduce the control torque output by the entire vehicle. When the target speed is less than the actual speed, the speed difference is positive, and the torque obtained after PI adjustment is positive. This positive value is then inverted to obtain a compensation torque, which is used to increase the control torque output by the entire vehicle and suppress motor vibration.

[0024] Preferably, the speed filtering module and the torque adjustment module are integrated into the vehicle controller, which is connected to the motor controller.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] 1. This invention adopts the most mature and widely used PID control algorithm in the industrial field, which is mature and reliable, suitable for engineering problems, and the algorithm is simple and clear;

[0027] 2. This invention achieves the effect of suppressing vehicle vibration by filtering the motor speed and compensating for the motor torque. Compared with ordinary models on the market, it greatly enhances the driver's comfort and avoids the risks caused by sudden changes in motor speed to a certain extent.

[0028] 3. A two-stage filtering scheme is adopted to process the rotational speeds obtained from different filtering systems simultaneously, and the final filtered rotational speed is obtained by weighting the processing, thereby improving the real-time performance of the filtering system. Attached Figure Description

[0029] Figure 1 This is a flowchart of the speed filtering processing module in this invention;

[0030] Figure 2 This is a flowchart of the torque adjustment module in this invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0032] Example 1

[0033] like Figures 1-2 As shown, a method for controlling vibration suppression in a new energy commercial vehicle includes:

[0034] Get the current speed and torque of the motor;

[0035] Speed ​​generation filtering module: Performs two-stage filtering on the current motor speed to obtain the first-stage filtered speed difference and the second-stage filtered speed difference. The first-stage filtering is a low-pass filter and the second-stage filtering is a mean filter.

[0036] The target speed difference of the motor is obtained by weighting the speed difference between the first-level filter and the speed difference between the second-level filter.

[0037] A simulation model was built based on Matlab / Simulink. The motor speed was obtained by using the jitter speed signal recorded from the actual vehicle and performing software unit model simulation to obtain the filtering coefficients and weighting coefficients.

[0038] The weighting coefficients are set to calibration values, and the weights of the first-level filter speed difference and the second-level filter speed difference are determined by combining real vehicle data. Both the weighting coefficients and the filter coefficients have reserved calibration value interfaces for real vehicle calibration.

[0039] Torque regulation module generation: Based on PID theory, a PI regulation module is established with the target speed difference of the motor as the input signal. The output motor compensation torque is introduced into the torque control loop and added to the current torque of the motor to realize the processing of the original torque and output control torque.

[0040] Vehicle calibration: The speed of the first-stage filter after low-pass filtering is obtained by calibrating the filter coefficients. The data of the first-stage filter speed and the second-stage filter speed are analyzed, the weighting coefficients are calibrated, and the final filter speed is obtained. By observing the deviation and margin of the compensation torque, the proportional and integral coefficients are calibrated to obtain the final compensation torque.

[0041] The data of the first-stage and second-stage filtered speeds are analyzed, and the weighting coefficients are calibrated to obtain the final filtered speed. Specifically, the first-stage and second-stage filtered speeds are compared with the motor speed before processing. The motor jitter frequency, signal delay, and distortion under the two-stage filtering are analyzed. The filter weights with better jitter suppression and weaker signal distortion are amplified. After comprehensively analyzing the above two-stage filtered signals, the weighting coefficients are calibrated to obtain the final filtered speed.

[0042] The first-level filtered speed difference is obtained by filtering the noise and interference at the current motor speed to get the first-level filtered speed, and then subtracting it from the current motor speed to get the first-level filtered speed difference value.

[0043] Where, the first-level filter speed = (1 - filter coefficient) × the speed filter result of the previous cycle + filter coefficient × the current motor speed;

[0044] The secondary speed difference signal is obtained by performing a 10-cycle mean filtering process on the motor speed to get the motor speed waveform, i.e., the secondary filtered speed. The difference between the secondary filtered speed and the current motor speed is obtained as the secondary filtered speed difference value.

[0045] A PI control module is established with the target speed difference of the motor as the input signal, and the output motor compensation torque signal is:

[0046] Compensated torque = proportional torque + integral torque;

[0047] Wherein, the proportional torque = proportional calibration coefficient KP × motor target speed difference;

[0048] Integral torque = Integral calibration coefficient KI × Σ motor target speed difference;

[0049] When the vehicle is currently in forward gear, the drive motor rotates forward. When the target speed of the motor is greater than the actual speed of the motor, the speed difference is negative, and the compensation torque obtained after PI adjustment is negative, which is used to reduce the control torque output of the whole vehicle. When the target speed is less than the actual speed, the speed difference is positive, and the compensation torque obtained after PI adjustment is positive, which is used to increase the control torque output of the whole vehicle and suppress motor vibration.

[0050] When the vehicle is currently in reverse gear, the drive motor reverses direction. When the target speed of the motor is greater than the actual speed, the speed difference is negative, and the torque obtained after PI adjustment is negative. This negative value is then inverted to obtain a compensation torque, which is used to reduce the control torque output by the entire vehicle. When the target speed is less than the actual speed, the speed difference is positive, and the torque obtained after PI adjustment is positive. This positive value is then inverted to obtain a compensation torque, which is used to increase the control torque output by the entire vehicle and suppress motor vibration.

[0051] The speed filtering module and torque regulation module are integrated into the vehicle controller, which is connected to the motor controller.

[0052] Example 2

[0053] When a car manufacturer matched a low-power motor with a peak power of 160kW, the vehicle experienced significant vibration during low-speed driving. After adjusting the mechanical structure and replacing the drive shaft, the vehicle performance did not improve significantly. Based on Matlab / Simulink, a speed filtering module and a torque adjustment module were developed.

[0054] Phase 1: Develop a speed filtering module. Input the current motor speed and perform two-stage filtering. The first stage is a low-pass filter, yielding the first-stage filtered speed. This first-stage filtered speed is then subtracted from the current motor speed to obtain the first-stage filtered speed difference. The second stage is a mean filter, applying a 10-cycle mean filter to the motor speed to obtain the second-stage filtered speed. This second-stage filtered speed difference is also subtracted from the current motor speed. The first-stage and second-stage filtered speed differences are then weighted to obtain the final target motor speed difference. Both the filtering coefficients and weighting coefficients have reserved calibration interfaces for real-vehicle calibration.

[0055] Phase 2: Develop a torque regulation module and establish a classic PI regulation module with the target motor speed difference as the target, outputting compensation torque; after inputting the target motor speed difference, proportional regulation and integral regulation are performed respectively to obtain the compensation torque, which is superimposed with the actual torque to output the final control torque; the proportional regulation coefficient and integral regulation coefficient are both reserved with calibration interfaces for actual vehicle calibration;

[0056] The speed filtering module and torque adjustment module are integrated into the vehicle controller. The vehicle controller combines the torque required by the driver, the torque requested by the transmission, and the vehicle operating conditions to make a comprehensive judgment and then sends the target torque to the motor controller. The motor controller, based on its own motor drive capability, outputs control torque to drive the motor.

[0057] The third stage involves real-vehicle calibration, which verifies the driving experience under various conditions such as low-speed driving, high-speed driving, small-scale start-up, large-scale start-up, and free driving. The calibration parameters are adjusted based on the actual operating conditions of the vehicle. The weighting coefficient is adjusted by observing the two filtering results, and the compensation torque is calibrated using the classic PID control approach, ultimately achieving vehicle vibration suppression.

Claims

1. A control method for suppressing vibration in new energy commercial vehicles, characterized in that, include: Get the current motor speed and torque; Speed ​​generation filtering module: Performs two-stage filtering on the current motor speed to obtain the first-stage filtered speed difference and the second-stage filtered speed difference. The first-stage filtering is a low-pass filter and the second-stage filtering is a mean filter. The target speed difference of the motor is obtained by weighting the speed difference between the first-level filter and the speed difference between the second-level filter. A simulation model was built based on Matlab / Simulink. The motor speed was obtained by using the jitter speed signal recorded from the actual vehicle and performing software unit model simulation to obtain the filtering coefficients and weighting coefficients. The weighting coefficients are set to calibration values, and the weights of the first-level filter speed difference and the second-level filter speed difference are determined by combining real vehicle data. Both the weighting coefficients and the filter coefficients have reserved calibration value interfaces for real vehicle calibration. Torque regulation module generation: Based on PID theory, a PI regulation module is established with the target speed difference of the motor as the input signal. The output motor compensation torque is introduced into the torque control loop and added to the current torque of the motor to realize the processing of the original torque and output control torque. Vehicle calibration: The speed of the first-stage filter after low-pass filtering is obtained by calibrating the filter coefficients. The data of the first-stage filter speed and the second-stage filter speed are analyzed, the weighting coefficients are calibrated, and the final filter speed is obtained. By observing the deviation and margin of the compensation torque, the proportional and integral coefficients are calibrated to obtain the final compensation torque.

2. The control method for suppressing vibration in new energy commercial vehicles according to claim 1, characterized in that, The first-level filtered speed difference is obtained by filtering the noise and interference at the current motor speed to get the first-level filtered speed, and then subtracting it from the current motor speed to get the first-level filtered speed difference value. Where, the first-level filter speed = (1 - filter coefficient) × the speed filter result of the previous cycle + filter coefficient × the current motor speed; The secondary speed difference signal is obtained by performing a 10-cycle mean filtering process on the motor speed to obtain the motor speed waveform, i.e., the secondary filtered speed. The difference between the secondary filtered speed and the current motor speed is obtained as the secondary filtered speed difference value.

3. The control method for suppressing vibration in new energy commercial vehicles according to claim 1, characterized in that, The PI control module, which uses the target speed difference of the motor as the input signal, outputs a motor compensation torque signal as follows: Compensated torque = proportional torque + integral torque; Wherein, the proportional torque = proportional calibration coefficient KP × motor target speed difference; Integral torque = Integral calibration coefficient KI × Σ motor target speed difference; When the vehicle is currently in forward gear, the drive motor rotates forward. When the target speed of the motor is greater than the actual speed of the motor, the speed difference is negative, and the compensation torque obtained after PI adjustment is negative, which is used to reduce the control torque output of the whole vehicle. When the target speed is less than the actual speed, the speed difference is positive, and the compensation torque obtained after PI adjustment is positive, which is used to increase the control torque output of the whole vehicle and suppress motor vibration. When the vehicle is currently in reverse gear, the drive motor reverses direction. When the target speed of the motor is greater than the actual speed, the speed difference is negative, and the torque obtained after PI adjustment is negative. This negative value is then inverted to obtain a compensation torque, which is used to reduce the control torque output by the entire vehicle. When the target speed is less than the actual speed, the speed difference is positive, and the torque obtained after PI adjustment is positive. This positive value is then inverted to obtain a compensation torque, which is used to increase the control torque output by the entire vehicle and suppress motor vibration.

4. The control method for suppressing vibration in new energy commercial vehicles according to claim 3, characterized in that, The speed filtering module and torque adjustment module are integrated into the vehicle controller, which is connected to the motor controller.

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