Control method for restraining jitter of new energy commercial vehicle

Abstract

The invention relates to a control method for restraining jitter of a new energy commercial vehicle. The current rotating speed and torque of a motor are obtained; performing two-stage filtering processing on the current rotating speed of the motor to obtain a first-stage filtering rotating speed difference value and a second-stage filtering rotating speed difference value, and performing weighting processing on the first-stage filtering rotating speed difference value and the second-stage filtering rotating speed difference value to obtain a target rotating speed difference of the motor; establishing a PI adjusting module taking the target rotating speed difference of the motor as an input signal, outputting a motor compensation torque, introducing the motor compensation torque into a torque control loop, adding the motor compensation torque to the current torque of the motor, processing the original torque, and outputting a control torque; the first-stage filtering rotating speed after low-pass filtering is obtained through calibration of the filtering coefficient, the weighting coefficient is calibrated, and the final filtering rotating speed is obtained; the final compensation torque is obtained by observing the deviation and the allowance of the compensation torque and calibrating the proportion and the integral coefficient, so that the purposes of inhibiting the motor jitter, not increasing the cost, being simple in algorithm and wide in adaptive range and solving the problem of vehicle jitter are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy commercial vehicle control, and particularly relates to a new energy commercial vehicle control method for suppressing jitter. BACKGROUND

[0002] The new energy commercial vehicle is a vehicle that meets the requirements of road traffic and safety regulations and is driven by a motor using a vehicle-mounted power source.

[0003] However, the new energy commercial vehicle may have torque jitter, which may cause the vehicle to jitter and other abnormal phenomena. To address this issue, the prior art CN106183888A discloses a vehicle anti-jitter method, system and motor controller. However, the prior art CN106183888A has the following problems: 1. A filter needs to be installed, which increases the cost; 2. The anti-jitter logic is realized only by the motor controller and external devices, and after engineering, there may be problems such as shift failure or driving abnormality caused by abnormal interaction between the motor and the transmission and the vehicle controller and response delay; and 3. The gain coefficient and other key parameters have no real vehicle calibration link, and there may be deviations between theory and practice, which is not suitable for actual engineering problems.

[0004] The prior art CN113183771A discloses an anti-jitter control method for an electric drive system. However, the prior art CN113183771A also has the following problems: 1. The estimated motor theoretical value has a large error and is not suitable for engineering; 2. The anti-jitter logic is realized only by the motor controller and external devices, and after engineering, there may be problems such as shift failure or driving abnormality caused by abnormal interaction between the motor and the transmission and the vehicle controller and response delay; and 3. The rotational speed filtering adopts a two-stage filtering superposition process, and the rotational speed obtained after the first-stage filtering enters the second-stage filter, which causes a large delay in the signal. For a millisecond-level change system such as motor control, this scheme has the risk of driving abnormality. SUMMARY

[0005] The present application aims to solve the problems of the prior art and provides a new energy commercial vehicle control method for suppressing jitter. The vehicle controller and the motor controller are jointly controlled, the results are weighted after two-stage filtering, the weighted rotational speed difference is converted into torque through PI adjustment, the torque is adjusted to compensate for the torque, and the purpose of suppressing motor jitter is achieved. This method does not increase the cost, has a simple algorithm, has a wide adaptation range, has obvious control effect, and effectively solves the problem of vehicle jitter.

[0006] The present application is implemented by using the following technical solutions:

[0007] A new energy commercial vehicle control method for suppressing jitter, comprising:

[0008] obtaining the current rotational speed and torque of the motor;

[0009] The rotational speed filtering processing module generates two-stage filtered rotational speed difference values by filtering the current rotational speed of the motor, wherein the first-stage filtering is low-pass filtering, and the second-stage filtering is mean filtering;

[0010] The motor target rotational speed difference is obtained by weighting the first-stage filtered rotational speed difference value and the second-stage filtered rotational speed difference value;

[0011] A simulation model is built based on Matlab / Simulink, the motor rotational speed adopts a recorded dithering rotational speed signal of an actual vehicle, a software unit model simulation is performed, and filtering coefficients and weighting coefficients are obtained;

[0012] The weighting coefficients are set as calibration values, the weights of the first-stage filtered rotational speed difference value and the second-stage filtered rotational speed difference value are determined in combination with actual vehicle data, and the filtering coefficients and the weighting coefficients are both reserved for calibration interfaces for actual vehicle calibration;

[0013] The torque adjustment module generates a motor compensation torque signal based on the PID theory by establishing a PI adjustment module with the motor target rotational speed difference as an input signal, and outputs the motor compensation torque signal.

[0014] Actual vehicle calibration: the first-stage filtered rotational speed after low-pass filtering is obtained by calibrating the filtering coefficients, the data of the first-stage filtered rotational speed and the second-stage filtered rotational speed are analyzed, the weighting coefficients are calibrated, and the final filtered rotational speed is obtained; the final compensation torque is obtained by calibrating the proportional and integral coefficients by observing the deviation and the margin of the compensation torque.

[0015] Preferably, the first-stage filtered rotational speed difference value is obtained by filtering the noise and interference of the current rotational speed of the motor to obtain a first-stage filtered rotational speed, and then subtracting the first-stage filtered rotational speed from the current rotational speed of the motor.

[0016] The first-stage filtered rotational speed = (1-filtering coefficient) x last period rotational speed filtering result + filtering coefficient x current rotational speed of the motor.

[0017] The second-stage rotational speed difference signal is obtained by performing mean filtering on the rotational speed of the motor for 10 periods to obtain a motor rotational speed waveform, i.e., a second-stage filtered rotational speed, and then subtracting the second-stage filtered rotational speed from the current rotational speed of the motor to obtain a second-stage filtered rotational speed difference value.

[0018] Preferably, the PI adjustment module with the motor target rotational speed difference as an input signal outputs a motor compensation torque signal, and the motor compensation torque signal is:

[0019] The compensation torque = proportional part torque + integral part torque.

[0020] The proportional part torque = proportional calibration coefficient KP x motor target rotational speed difference.

[0021] Integral part torque = integral calibration coefficient KI x Sigma motor target rotating speed difference

[0022] When the current gear of the vehicle is forward gear, the driving motor rotates forward; when the motor target rotating speed > the motor actual rotating speed, the rotating speed difference is negative, the compensation torque obtained after PI adjustment is negative, which is used to reduce the control torque of the vehicle output; when the target rotating speed < the actual rotating speed, the rotating speed difference is positive, the compensation torque obtained after PI adjustment is positive, which is used to improve the control torque of the vehicle output, so as to realize the suppression of motor jitter.

[0023] When the current gear of the vehicle is reverse gear, the driving motor rotates reversely; when the motor target rotating speed > the motor actual rotating speed, the rotating speed difference is negative, the torque obtained after PI adjustment is negative, which is inverted to obtain the compensation torque, which is used to reduce the control torque of the vehicle output; when the target rotating speed < the actual rotating speed, the rotating speed difference is positive, the torque obtained after PI adjustment is positive, which is inverted to obtain the compensation torque, which is used to improve the control torque of the vehicle output, so as to realize the suppression of motor jitter.

[0024] Preferably, the rotating speed filtering processing module and the torque adjustment module are integrated in the vehicle controller, and the vehicle controller is connected with the motor controller.

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

[0026] 1. The application adopts the most mature and widely used PID control algorithm in the industry, which is mature and reliable, suitable for engineering problems, and the algorithm is simple and clear.

[0027] 2. The application realizes the effect of vehicle jitter suppression by filtering the motor rotating speed and adjusting the motor torque compensation, greatly enhances the comfort of the driver compared with the ordinary vehicle in the market, and avoids the risk caused by the sudden change of the motor rotating speed to a certain extent.

[0028] 3. The two-stage filtering scheme is adopted to weight the rotating speeds obtained by different filtering systems to obtain the final filtering rotating speed, which enhances the real-time performance of the filtering system. BRIEF DESCRIPTION OF DRAWINGS

[0029] Fig. 1 The flow chart of the rotating speed filtering processing module in the application is shown in the figure.

[0030] Fig. 2 The flow chart of the torque adjustment module in the application is shown in the figure. DETAILED DESCRIPTION

[0031] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the scope of protection of the present application.

[0032] Embodiment one

[0033] As shown in the figure, a new energy commercial vehicle jitter suppression control method, comprising: Figs. 1-2

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

[0035] Generating a speed filtering processing module: two-stage filtering processing is performed on the current speed of the motor to obtain a first-stage filtering speed difference value and a second-stage filtering speed difference value, wherein the first-stage filtering is low-pass filtering, and the second-stage filtering is mean filtering;

[0036] Performing weighted processing on the first-stage filtering speed difference value and the second-stage filtering speed difference value to obtain a motor target speed difference;

[0037] Based on Matlab / Simulink, a simulation model is built, the motor speed uses the jitter speed signal recorded by the real vehicle, the software unit model simulation is performed, the filtering coefficient and the weighting coefficient are obtained;

[0038] The weighting coefficient is set as a calibration quantity, combined with the real vehicle data, the weight of the first-stage filtering speed difference value and the second-stage filtering speed difference value is determined; the weighting coefficient and the filtering coefficient are both reserved for calibration interface for real vehicle calibration;

[0039] Generating a torque adjustment module: based on the PID theory, a PI adjustment module is established with the motor target speed difference as the input signal, the motor compensation torque is output, the motor compensation torque is introduced into the torque control loop, and the motor current torque is added to realize the processing of the original torque, and the control torque is output;

[0040] Real vehicle calibration: the first-stage filtering speed after low-pass filtering is obtained by calibrating the filtering coefficient, the data of the first-stage filtering speed and the second-stage filtering speed are analyzed, the weighting coefficient is calibrated, and the final filtering speed is obtained; by observing the deviation and the margin of the compensation torque, the proportional and integral coefficients are calibrated, and the final compensation torque is obtained.

[0041] ​The first-stage filtering rotation speed difference is obtained by filtering the noise and interference of the current rotation speed of the motor to obtain a first-stage filtering rotation speed, and then subtracting the current rotation speed of the motor from the first-stage filtering rotation speed.

[0042] The first-stage filtering rotation speed difference is obtained by filtering the noise and interference of the current rotation speed of the motor to obtain a first-stage filtering rotation speed, and then subtracting the current rotation speed of the motor from the first-stage filtering rotation speed.

[0043] The first-stage filtering rotation speed is equal to (1-filtering coefficient) multiplied by the filtering result of the rotation speed of the previous period, plus the filtering coefficient multiplied by the current rotation speed of the motor.

[0044] The second-stage rotation speed difference signal is obtained by performing 10-period mean filtering on the rotation speed of the motor to obtain a motor rotation speed waveform, i.e., a second-stage filtering rotation speed, and then subtracting the current rotation speed of the motor from the second-stage filtering rotation speed.

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

[0046] The compensation torque is equal to the proportional part torque plus the integral part torque.

[0047] The proportional part torque is equal to the proportional calibration coefficient KP multiplied by the motor target rotation speed difference.

[0048] The integral part torque is equal to the integral calibration coefficient KI multiplied by the sum of the motor target rotation speed differences.

[0049] When the current gear of the vehicle is the forward gear, the drive motor rotates forward; when the motor target rotation speed is greater than the actual rotation speed of the motor, the rotation speed difference is negative, and the compensation torque obtained after PI adjustment is negative, which is used to reduce the control torque output by the vehicle; when the target rotation speed is less than the actual rotation speed, the rotation speed difference is positive, and the compensation torque obtained after PI adjustment is positive, which is used to increase the control torque output by the vehicle, thereby achieving suppression of motor jitter.

[0050] When the current gear of the vehicle is the reverse gear, the drive motor rotates in reverse; when the motor target rotation speed is greater than the actual rotation speed of the motor, the rotation speed difference is negative, and the torque obtained after PI adjustment is negative, which is inverted to obtain the compensation torque, which is used to reduce the control torque output by the vehicle; when the target rotation speed is less than the actual rotation speed, the rotation speed difference is positive, and the torque obtained after PI adjustment is positive, which is inverted to obtain the compensation torque, which is used to increase the control torque output by the vehicle, thereby achieving suppression of motor jitter.

[0051] The rotation speed filtering processing module and the torque adjusting module are integrated in the vehicle controller, and the vehicle controller is connected with the motor controller.

[0052] Embodiment two

[0053] A vehicle manufacturer matched a small power motor with a peak power of 160kw, and the vehicle had a problem of obvious shaking during low-speed driving. After adjusting the mechanical structure and replacing the transmission shaft, the vehicle performance did not improve significantly. Based on Matlab / Simulink, a rotation speed filtering processing module and a torque adjusting module were developed.

[0054] First stage: develop a rotation speed filtering processing module, input the current rotation speed of the motor, and perform two-stage filtering processing on the current rotation speed of the motor. The first-stage filtering is low-pass filtering, and the first-stage filtered rotation speed difference is obtained by subtracting the first-stage filtered rotation speed from the current rotation speed of the motor. The second-stage filtering is mean filtering, and the second-stage filtered rotation speed is obtained by performing mean filtering processing on the motor rotation speed for 10 cycles. The second-stage filtered rotation speed difference is obtained by subtracting the second-stage filtered rotation speed from the current rotation speed of the motor. The first-stage filtered rotation speed difference and the second-stage filtered rotation speed difference are weighted to obtain the final motor target rotation speed difference. The filtering coefficients and the weighting coefficients are both reserved for calibration interfaces for real vehicle calibration.

[0055] Second stage: develop a torque adjusting module, establish a classic PI adjusting module with the motor target rotation speed difference as the target, and output the compensation torque. After inputting the motor target rotation speed difference, proportional adjustment and integral adjustment are performed respectively to obtain the compensation torque. The final control torque is obtained by superimposing the compensation torque and the actual torque. The proportional adjustment coefficient and the integral adjustment coefficient are both reserved for calibration interfaces for real vehicle calibration.

[0056] The rotation speed filtering processing module and the torque adjusting module are integrated into the vehicle controller. The vehicle controller sends the motor controller target torque after adjusting and comprehensively judging the driver demand torque, the transmission request torque, and the vehicle operating conditions. The motor controller outputs the control torque to drive the motor based on the driving ability of the motor itself.

[0057] Third stage, real vehicle calibration, respectively, vehicle low-speed driving, high-speed driving, small door starting, large throttle starting, free driving and other conditions of driving feeling verification, combined with the actual running state of the vehicle to adjust the calibration quantity, by observing the two filtering results to adjust the weighting coefficient, combined with the classic PID adjusting idea to calibrate the compensation torque, and finally complete the vehicle shaking suppression.

Claims

1. A control method for suppressing jitter of a new energy commercial vehicle, characterized in that, The method comprises the following steps: acquiring the current speed and torque of the motor; generating a speed filtering processing module: two-stage filtering processing is performed on the current speed of the motor to obtain a first-stage filtering speed difference value and a second-stage filtering speed difference value, wherein the first-stage filtering is low-pass filtering, and the second-stage filtering is mean filtering; performing weighted processing on the first-stage filtering speed difference value and the second-stage filtering speed difference value to obtain a motor target speed difference value; building a simulation model based on Matlab / Simulink, using a recorded dithering speed signal of an actual vehicle as the motor speed, performing software unit model simulation to obtain filtering coefficients and weighted coefficients; setting the weighted coefficients as calibration values, combining the actual vehicle data to determine the weights of the first-stage filtering speed difference value and the second-stage filtering speed difference value; the weighted coefficients and the filtering coefficients are both provided with calibration value interfaces for actual vehicle calibration; generating a torque adjusting module: based on the PID theory, a PI adjusting module is established with the motor target speed difference value as an input signal, and a motor compensation torque is outputted; the motor compensation torque is introduced into a torque control loop and added to the current torque of the motor to realize processing on the original torque and output a control torque; actual vehicle calibration: the first-stage filtering speed after low-pass filtering is obtained through calibration of the filtering coefficients; the data of the first-stage filtering speed and the second-stage filtering speed are analyzed to calibrate the weighted coefficients and obtain the final filtering speed; the final compensation torque is obtained by observing the deviation and margin of the compensation torque and calibrating the proportional and integral coefficients.

2. The control method for suppressing jitter of a new energy commercial vehicle according to claim 1, characterized in that, The first-stage filtering speed difference value is obtained by filtering the noise and interference of the current speed of the motor to obtain a first-stage filtering speed, and then subtracting the first-stage filtering speed from the current speed of the motor; wherein the first-stage filtering speed = (1-filtering coefficient)×previous period speed filtering result + filtering coefficient×current speed of the motor; The second-stage speed difference signal is obtained by performing mean filtering on the motor speed for 10 periods to obtain a motor speed waveform, i.e. a second-stage filtering speed, and then subtracting the second-stage filtering speed from the current speed of the motor to obtain a second-stage filtering speed difference value.

3. The control method for suppressing jitter of a new energy commercial vehicle according to claim 1, characterized in that, The PI adjusting module with the motor target speed difference value as an input signal outputs a motor compensation torque signal, which is: compensation torque = proportional part torque + integral part torque; wherein the proportional part torque = proportional calibration coefficient KP×motor target speed difference value; the integral part torque = integral calibration coefficient KI×Σmotor target speed difference value; when the current gear of the vehicle is the forward gear, the driving motor rotates in the positive direction; when the motor target speed > 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 by the vehicle; when the target speed < 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 by the vehicle, thereby realizing suppression of the motor dithering. When the current gear of the vehicle is in reverse, the drive motor is reversed; when the target speed of the motor is greater than the actual speed of the motor, the speed difference is negative, the torque obtained after PI adjustment is negative, the compensation torque obtained by taking the inverse is used to reduce the control torque of the vehicle output; when the target speed is less than the actual speed, the speed difference is positive, the torque obtained after PI adjustment is positive, the compensation torque obtained by taking the inverse is used to increase the control torque of the vehicle output, so as to realize the suppression of motor jitter.

4. The control method for suppressing jitter of a new energy commercial vehicle according to claim 3, characterized in that, The speed filtering processing module and the torque adjusting module are integrated in the vehicle controller, and the vehicle controller is connected with the motor controller.

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