阅读说明：本技术 一种纯电动客车车辆扭矩过零时消抖的处理方法 (Processing method for eliminating shake of pure electric passenger vehicle during zero-crossing torque ) 是由 张旭佶 楼佳烽 梅云龙 杨明 于 2021-08-13 设计创作，主要内容包括：本发明涉及车辆设计技术领域,尤其是一种纯电动客车车辆扭矩过零时消抖的处理方法,通过调控正负扭矩切换时的输出延时,使扭矩维持一定时间的零扭矩输出来缓解齿轮的啮合面冲击,以此增加车辆平顺性。本发明根据车辆当前的运行状况,调整车辆转矩输出的大小与时机,在确保纯电动客车驱动有效和制动回收的同时,可有效减少齿轮啮合冲击,提高车辆平顺性。(The invention relates to the technical field of vehicle design, in particular to a method for eliminating shake when the torque of a pure electric bus passes through zero. The invention adjusts the magnitude and the time of the vehicle torque output according to the current running condition of the vehicle, can effectively reduce the gear meshing impact and improve the vehicle smoothness while ensuring the driving effectiveness and the braking recovery of the pure electric motor coach.)

1. A processing method for eliminating shake when the torque of a pure electric bus passes through zero is characterized by comprising the following steps:

(1) the vehicle control unit judges the intention of a driver on the basis of the opening degree of an accelerator pedal, the vehicle speed, the rotating speed of a motor and the state of a brake switch, and sends a control signal of required torque to the motor controller according to a judgment result; the required torque is divided into positive torque and negative torque, the positive torque is used for driving the vehicle to advance, an accelerator pedal is stepped on, the positive torque requirement is increased, and the vehicle enters an acceleration state; the negative torque is used for realizing energy recovery when the vehicle slides or brakes, and when a brake pedal is stepped or an accelerator pedal is loosened, the requirement of the negative torque is increased, and the vehicle enters a deceleration state;

the whole-process collection of the vehicle control unit is that the torque signal actually output by the motor is analyzed to obtain the current torque; comparing the current torque with the required torque, and if the change speed and the change trend of the current torque exceed the change range of the required torque, filtering and adjusting a control signal of the required torque sent to a motor controller by the vehicle controller;

(2) establishing a planar rectangular coordinate system, wherein the horizontal axis is time, the vertical axis is required torque, and the numerical value of the required torque is calibrated in the planar rectangular coordinate system;

in a first quadrant of the rectangular plane coordinate system, the required torque is positive torque, and K1 is the maximum slope in the reduction process of the positive torque under the normal driving state; under normal driving conditions, the positive torque of the vehicle can only be reduced by a value less than or equal to K1 in the smallest time unit;

Δ t1 is the time during which the torque output of 0 is maintained during the transition from positive to negative torque;

if the required torque has a positive increasing change trend within the time of delta t1, the vehicle controller directly sends a control signal that the output torque is positive to the motor controller under the condition that the driving flag bit is effective, the vehicle controller does not continuously keep the 0 torque until the time of delta t1 is finished, wherein the driving flag bit related factors comprise whether the vehicle is high-voltage READY, whether the hand brake is released, whether front and rear doors are closed, whether the front and rear doors are shifted to D or R, whether a triggering braking priority working condition exists, and whether an accelerator mistaken-stepping triggering function exists; the magnitude of the output positive torque is determined by the maximum driving torque of the current allowable request, the state and the opening degree of an accelerator pedal and the power state of the whole vehicle;

if the required torque has no change trend of positive increase within the time of delta t1, after the 0-moment output is maintained within the time of delta t1, the vehicle control unit sends a control signal that the output torque is negative torque to the motor controller, the negative torque is gradually increased, the feedback effect is improved, and the required torque enters the fourth quadrant; k2 is the absolute value of the maximum slope in the negative torque increasing process, and under the normal driving state, the absolute value of the negative torque of the vehicle increased in the minimum time unit can only be less than or equal to K2;

in the fourth quadrant, the required torque is negative torque in a normal driving state, k3 is the absolute value of the maximum slope in the negative torque reduction process, and the absolute value of the reduction value of the negative torque of the vehicle in the minimum time unit in the normal driving state can only be less than or equal to k 3;

Δ t2 is the time to maintain a 0 torque output during the negative to positive torque transition;

if the required torque has a negative increasing change trend within the time of delta t2, the vehicle controller directly sends a control signal that the output torque is negative torque to the motor controller under the condition that a feedback flag bit is effective, the vehicle controller does not continuously keep the 0 torque until the time of delta t2 is finished, wherein the relevant factors of the feedback flag bit comprise whether the vehicle is high-voltage READY, whether a hand brake is released, whether the vehicle is in a forward gear, whether the battery SOC and the allowed maximum charging current meet the feedback condition, whether the ABS is activated, whether the motor has a serious fault, and the magnitude of the output negative torque is determined by the maximum feedback torque of the current allowed request, the current motor rotating speed, the brake pedal state and the opening degree thereof;

if the required torque has no negative increasing change trend within the time of delta t2, after the torque output of 0 is maintained within the time of delta t2, the vehicle control unit sends a control signal that the output torque is positive torque to the motor controller, the positive torque is gradually increased, the driving effect is improved, the required torque enters the first quadrant again, K4 is the maximum slope in the increasing process of the positive torque, and the increasing value of the positive torque within the minimum time unit can only be less than or equal to K4.

2. The method for eliminating the trembling when the torque of the pure electric bus vehicle passes through zero according to claim 1, wherein the range of Δ t1 is 0.3 s-0.5 s, and the range of Δ t2 is 0.1 s-0.3 s.

Technical Field

The invention relates to the technical field of vehicle design, in particular to a method for eliminating shake when the torque of a pure electric bus passes through zero.

Background

At present, the running state of the pure electric passenger car is mainly divided into acceleration driving and deceleration feedback, and the latter can be roughly divided into sliding feedback and braking feedback under the condition of meeting a certain feedback condition. In the driving process of the vehicle, switching between different driving states can often occur based on different road conditions and driving habits of drivers. Practice shows that in certain specific rotating speed regions or moment zero-crossing switching points, meshing surfaces of gear transmission can be changed immediately and are transferred from one side to the other side, when gear gaps are slightly large, noise is generated due to meshing impact in the process of changing the torque driving direction, a vehicle body shakes, and the NVH quality of the whole vehicle is affected.

In order to alleviate or eliminate the zero-crossing moment impact caused by the objective existence of the gear clearance, the conventional common vehicle shake elimination method comprises the following steps: (1) the manufacturing and assembling precision of the gear is improved to reduce the gear clearance; (2) the change slope of the moment is limited, so that the driving wheel is slowly attached to the meshing surface of the driven wheel, and the impact is reduced, so that the moment curve is smooth and mild; (3) the rotating speed signal is filtered to eliminate burrs, so that a stable rotating speed value can be obtained to ensure the stability of the calculated output torque value. The above-mentioned jitter elimination method has the following disadvantages: (1) improving the manufacturing and assembling precision of the gear can greatly improve the production cost and still can not completely solve the impact problem; (2) the limiting moment change slope is limited by axle technical parameters, and the response to large change of the moment in a short time is slow, so that the limiting moment change slope is not beneficial to timely transmitting the intention of a driver; (3) filtering the speed signal reduces the effectiveness and real-time of the data volume.

Disclosure of Invention

The invention aims to overcome the defects in the background technology, and provides a method for processing the pure electric bus to eliminate vehicle shake.

The technical scheme adopted by the invention is as follows: a processing method for eliminating shake when the torque of a pure electric bus passes through zero comprises the following steps:

(1) the vehicle control unit judges the intention of a driver on the basis of the opening degree of an accelerator pedal, the vehicle speed, the rotating speed of a motor and the state of a brake switch, and sends a control signal of required torque to the motor controller according to a judgment result; the required torque is divided into positive torque and negative torque, the positive torque is used for driving the vehicle to advance, an accelerator pedal is stepped on, the positive torque requirement is increased, and the vehicle enters an acceleration state; the negative torque is used for realizing energy recovery when the vehicle slides or brakes, and when a brake pedal is stepped or an accelerator pedal is loosened, the requirement of the negative torque is increased, and the vehicle enters a deceleration state;

the whole-process collection of the vehicle control unit is that the torque signal actually output by the motor is analyzed to obtain the current torque; comparing the current torque with the required torque, and if the change speed and the change trend of the current torque exceed the change range of the required torque, filtering and adjusting a control signal of the required torque sent to a motor controller by the vehicle controller;

(2) establishing a planar rectangular coordinate system, wherein the horizontal axis is time, the vertical axis is required torque, and the numerical value of the required torque is calibrated in the planar rectangular coordinate system;

in a first quadrant of the rectangular plane coordinate system, the required torque is positive torque, and K1 is the maximum slope in the reduction process of the positive torque under the normal driving state; under normal driving conditions, the positive torque of the vehicle can only be reduced by a value less than or equal to K1 in the smallest time unit;

Δ t1 is the time during which the torque output of 0 is maintained during the transition from positive to negative torque;

if the required torque has a positive increasing change trend within the time of delta t1, the vehicle controller directly sends a control signal that the output torque is positive to the motor controller under the condition that the driving flag bit is effective, the vehicle controller does not continuously keep the 0 torque until the time of delta t1 is finished, wherein the driving flag bit related factors comprise whether the vehicle is high-voltage READY, whether the hand brake is released, whether front and rear doors are closed, whether the front and rear doors are shifted to D or R, whether a triggering braking priority working condition exists, and whether an accelerator mistaken-stepping triggering function exists; the magnitude of the output positive torque is determined by the maximum driving torque of the current allowable request, the state and the opening degree of an accelerator pedal and the power state of the whole vehicle;

if the required torque has no change trend of positive increase within the time of delta t1, after the 0-moment output is maintained within the time of delta t1, the vehicle control unit sends a control signal that the output torque is negative torque to the motor controller, the negative torque is gradually increased, the feedback effect is improved, and the required torque enters the fourth quadrant; k2 is the absolute value of the maximum slope in the negative torque increasing process, and under the normal driving state, the absolute value of the negative torque of the vehicle increased in the minimum time unit can only be less than or equal to K2;

in the fourth quadrant, the required torque is negative torque under a normal driving state, k3 is the absolute value of the maximum slope in the negative torque reduction process, and the absolute value of the reduction value of the negative torque of the vehicle in the minimum time unit under the normal driving state can only be less than or equal to k 3;

Δ t2 is the time to maintain a 0 torque output during the negative to positive torque transition;

if the required torque has a negative increasing change trend within the time of delta t2, the vehicle controller directly sends a control signal that the output torque is negative torque to the motor controller under the condition that a feedback flag bit is effective, the vehicle controller does not continuously keep the 0 torque until the time of delta t2 is finished, wherein the relevant factors of the feedback flag bit comprise whether the vehicle is high-voltage READY, whether a hand brake is released, whether the vehicle is in a forward gear, whether the battery SOC and the allowed maximum charging current meet the feedback condition, whether the ABS is activated, whether the motor has a serious fault, and the magnitude of the output negative torque is determined by the maximum feedback torque of the current allowed request, the current motor rotating speed, the brake pedal state and the opening degree thereof;

if the required torque has no negative increasing change trend in the time of delta t2, after the output of 0 torque is maintained in the time of delta t2, the required torque outputs positive torque and the positive torque is gradually increased, the driving effect is improved, the required torque enters the first quadrant again, K4 is the maximum slope in the increasing process of the positive torque, and the increasing value of the positive torque in the minimum time unit can only be less than or equal to K4.

Preferably, Δ t1 is in the range of 0.3s to 0.5s and Δ t2 is in the range of 0.1s to 0.3 s.

The invention has the beneficial effects that: the invention enhances the control of the vehicle, effectively weakens and eliminates the vehicle body vibration in the vehicle running process, reduces the loss of the driving axle gear and improves the vehicle running stability by regulating and controlling the required torque output by the vehicle controller and cooperating with the existing vehicle shaking eliminating mode on the basis of ensuring the intention of a driver. In addition, the invention is suitable for various passenger cars such as new energy pure electric vehicles, hybrid power vehicles and the like, and has wide application range.

Drawings

FIG. 1 is a schematic diagram of a rectangular plane coordinate system according to the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples, but the present invention is not limited to the following examples, so that the objects, solutions and advantages of the present invention can be more clearly understood by those skilled in the art.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified and limited, specific meanings of the general terms in the present invention may be specifically understood by those skilled in the art.

In the method for processing shake elimination when the torque of the pure electric bus passes through zero, the vehicle controller judges the intention of a driver on the basis of the opening degree of an accelerator pedal, the speed, the rotating speed of a motor and the state of a brake switch, and sends a control signal of required torque to the motor controller according to a judgment result. The required torque is divided into positive torque and negative torque, the positive torque is used for driving and running the vehicle, for example, a driver steps on an accelerator pedal, the positive torque demand is increased, and the vehicle enters an acceleration state correspondingly; the negative torque is used for realizing energy recovery when the vehicle slides or brakes, and if a brake pedal is stepped on or an accelerator pedal is released, the negative torque demand is increased, and the vehicle enters a deceleration state correspondingly.

The whole-process collection of the vehicle control unit is that the torque signal actually output by the motor is analyzed to obtain the current torque; and comparing the current torque with the required torque, and if the change speed and the change trend of the current torque exceed the change range of the required torque, filtering and adjusting a control signal of the required torque sent to the motor controller by the vehicle controller.

The vehicle control unit collects a torque signal output by the motor, analyzes the torque signal to obtain a current torque signal of the motor, compares the current torque with a required torque, and performs filtering adjustment on a control signal of the required torque sent to the motor controller by the vehicle control unit if the change speed and the change trend of the current torque exceed the change range of the required torque, so that a torque output curve of the vehicle control unit is changed, and the torque output by the motor more meets the requirements of a driver.

As shown in fig. 1, the vehicle control unit establishes a planar rectangular coordinate system, the horizontal axis is time, the vertical axis is required torque, and the value of the required torque is calibrated in the planar rectangular coordinate system.

In the first quadrant of the rectangular plane coordinate system, the required torque is the positive torque for driving the vehicle to move under the normal driving state. K1 is the maximum slope during positive torque reduction in the normal driving state. In normal driving conditions, the positive torque of the vehicle can only be reduced by a value less than or equal to K1 in the smallest time unit.

Δ t1 is the time during which a torque output of 0 is maintained during the positive to negative torque transition.

If the vehicle controller detects that the required torque has a positive increasing change trend within the time of delta t1, the vehicle controller directly sends a control signal that the output torque is positive to the motor controller under the condition that the driving flag bit is effective, the vehicle controller does not continuously maintain the torque of 0 until the time of delta t1 is over, wherein the driving flag bit related factors comprise whether the vehicle is high-voltage READY, whether the hand brake is released, whether front and rear doors are closed, whether the front and rear doors are shifted to D or R, whether a braking priority working condition is triggered, and whether an accelerator mistaken-stepping triggering function is triggered. The magnitude of the output positive torque is determined by the maximum driving torque of the current allowable request, the state and the opening degree of an accelerator pedal and the power state of the whole vehicle.

If the vehicle control unit does not detect the positive increasing change trend of the required torque within the time delta t1, after the 0-moment output is maintained within the time delta t1, the vehicle control unit sends a control signal that the output torque is negative torque to the motor controller, the negative torque is gradually increased, the feedback effect is improved, and the required torque enters the fourth quadrant. K2 is the absolute value of the maximum slope during negative torque increase, and the absolute value of the value at which the negative torque of the vehicle increases in the minimum time unit under normal driving conditions can only be less than or equal to K2.

In the fourth quadrant, the required torque is a negative torque in a normal driving state, k3 is an absolute value of a maximum slope in a negative torque reduction process, and an absolute value of a reduction value of the negative torque of the vehicle in a minimum time unit in the normal driving state can only be less than or equal to k 3.

If the vehicle controller detects that the required torque has a negative increasing change trend within the time of delta t2, the vehicle controller directly sends a control signal that the output torque is negative torque to the motor controller under the condition that a feedback flag bit is effective, the vehicle controller does not continuously maintain the 0 torque until the time of delta t2 is finished, wherein the relevant factors of the feedback flag bit comprise whether the vehicle is in high voltage READY, whether a hand brake is released, whether the vehicle is in a forward gear, whether the battery SOC and the allowed maximum charging current meet the feedback condition, whether the ABS is activated, and whether the motor has a serious fault. The output negative torque is determined by the maximum feedback torque allowed to be requested currently, the current motor speed, the brake pedal state (for judging whether the brake feedback or the sliding feedback is performed) and the opening degree of the brake pedal state.

If the vehicle control unit does not detect the change trend of the negative increase of the required torque within the time delta t2, after the 0-moment output is maintained within the time delta t2, the vehicle control unit sends a control signal that the output torque is the positive torque to the motor controller, the positive torque is gradually increased, the driving effect is improved, and the required torque enters the first quadrant again. K4 is the maximum slope during the increase of positive torque, which can only increase by a value less than or equal to K4 in the smallest time unit.

In the above, the time setting of Δ t1 and Δ t2 needs to comprehensively consider the parameters of motors and axles equipped for different vehicle types, and the optimal values are selected through multiple experiments, wherein Δ t1 is between 0.3s and 0.5s, and Δ t2 is between 0.1s and 0.3 s. In the present invention, an increase in negative torque means an increase in the absolute value of negative torque, and a decrease in negative torque means a decrease in the absolute value thereof.

The processing method provided by the invention is not only suitable for the driver operation in the normal running process of the vehicle, but also suitable for the condition that the vehicle has an abnormal state, such as serious failure and common failure of a power system in the running process, and the vehicle correspondingly executes active parking power-off, zero-power running and stopping and the like.

According to the invention, the zero torque output of the torque for a certain time is maintained to relieve the meshing surface impact of the gear by regulating and controlling the output delay during the switching of the positive torque and the negative torque, so that the smoothness of the vehicle is improved.

The above description is only a preferred embodiment of the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.