CN103522915A

CN103522915A - Torque control method for preventing backward slipping of blade electric vehicle on slope

Info

Publication number: CN103522915A
Application number: CN201310532701.5A
Authority: CN
Inventors: 冯超; 刘宇; 王艳静
Original assignee: 重庆长安汽车股份有限公司; 重庆长安新能源汽车有限公司
Priority date: 2013-10-31
Filing date: 2013-10-31
Publication date: 2014-01-22
Also published as: CN103522915B

Abstract

A torque control method for preventing backward slipping of a blade electric vehicle on a slope comprises the steps of first simulating the low-speed creeping process of a traditional car, wherein the speed of a controlled target on a ramp or a plain road is 8km/h; utilizing closed-loop PI control, calibrating P and I parameters at different motor rotating speeds, accordingly enabling the electric vehicle to obtain torque required by driving when a brake pedal is loosened within 0.3s, rapidly achieving ideal driving vehicle speed and avoiding the backward slipping after a driver loosens a brake.

Description

A kind of pure electric automobile prevents the torque control method slipping after hill start

Technical field

The invention belongs to new-energy automobile electric control system controls field, relate to the torque control method to new-energy automobile.

Background technology

Enter 21 century global climate and warm gradually, the exhaustion of the soaring and oil resources of oil price, energy-saving low-carbon trip becomes people's common recognition gradually, and new-energy automobile is the effective measures of alleviating Pressure on Energy and reducing environmental pollution.Along with popularizing of new-energy automobile, except the effect of riding instead of walk of automobile, more pursued the comfort property of automobile.New-energy automobile majority has adopted motor and single reduction gear scheme, thereby the resistance of driving system is little with respect to the resistance of traditional vehicle driving engine and multi-stage speed reducer; The closed-center system of electronlmobil is power brick, causes the car weight of battery-driven car to improve a lot compared with orthodox car.Because the heavier while resistance of vehicle is less, thereby cause vehicle more obvious compared with orthodox car when hill start is slipped slope (cycling start of Ji Po road be occur slipping slope).

Conventional gasoline machine automobile is in order to address this problem, conventionally adopted with the brake system of upward slope additional function (HAC) and slipped the problem on slope to eliminate hill start, but this brake system has not only changed the brake system of orthodox car, also to car load, increased higher cost simultaneously.

Application publication number is that the patent documentation of CN 101817313A discloses a kind of " ramp safe starting control system of electric vehicle ", the problem of its existence is: 1,, due to road surface situation, car load situation difference, control system cannot calculate various ramps grade information accurately by vehicle speed signal; 2, after only having and slipping, can carry out correlated judgment after car.

Summary of the invention

The present invention is the torque control method slipping after a kind of pure electric automobile prevents, object is in the situation that not changing brake system structure, by a kind of more advanced mode, solves hill start and slips the problem on slope.

Technical solution of the present invention comprises following content:

The speed of a motor vehicle that entire car controller (VCU) first provides according to Das Gaspedal aperture, brake pedal information, gear information, motor speed, ABS and complete vehicle fault state, judging whether the residing state of car load should enter prevents from slipping slope master mode, and enables torque arithmetic module.Judgement enters the condition that this pattern need possess and comprises: motor speed does not enable during from slow speed of revolution rising 1400rpm, from high rotating speed, declines, and during lower than 1200rpm, enables; Brake pedal is not stepped on; Shift signal is D gear or R gear; Do not have car load to forbid the fault of moment of torsion output; There is no cell safety fault.

When whole vehicle state allows to enter while preventing from slipping slope master mode, entire car controller (VCU) starts to calculate target vehicle speed, in starting, target vehicle speed V_Target is constantly 0-8km/h, being certain slope (as 2s) increases, to 8km/h, be stable objects value, to guarantee the steady of the speed of a motor vehicle of starting to walk.The actual vehicle speed V_Act of ABS feedback sends to entire car controller (VCU); Entire car controller calculates the difference (Delta_V) of target vehicle speed and actual vehicle speed, thereby carries out the closed loop PI control of moment of torsion.

The torque Tq=P*Delta_V+I*Delta_V of the actual output of vehicle control unit controls electric system; Wherein P, I item are reconcilable parameter, need under different operating modes, demarcate design, according to the speed of a motor vehicle, proofread and correct, and under D blend stop part, when the speed of a motor vehicle is less or be negative value, P item parameter is larger; When the speed of a motor vehicle approaches with target vehicle speed, P, I item parameter are less.Reverse gear principle is consistent.

First this programme is the process of having simulated the low speed crawling of orthodox car, at chaufeur take-off the brake, under the condition of step on the accelerator, can not move ahead slowly.So the control target of this programme is that the speed of a motor vehicle on ramp or level road equals 8km/h, but not the control program that target vehicle speed in above-mentioned patent is 0.

For conventional gasoline machine, due to electric system utilization is that electric energy conversion is energy controlling torque output, and conventional engines utilization is that moment of torsion output is adjusted in throttle opening and oil spout igniting, make conventional gasoline machine when hill start, have the long slope process of slipping.The method has been brought into play the advantage that pure electric vehicle electric system is different from regular price gasoline driving engine, and Motor torque speed of response will be much larger than the response characteristic of driving engine.Thereby the torque rate of rise maximum of motor output can arrive 800Nm/s, therefore utilize PI to control, can drive needed moment of torsion so that electronlmobil reaches in the 0.3s of loosen the brake, and reach rapidly the desirable driving speed of a motor vehicle, avoid after chaufeur take-off the brake after slip process.

This programme is for the operating mode of uphill starting, for the different speed of a motor vehicle and motor speed, carried out adaptive design, by demarcating P, the I parameter under different motor speeds, when the speed of a motor vehicle is less or be negative value, P, I parameter are larger, so that moment of torsion can be climbed to target vehicle speed required torque.When the speed of a motor vehicle approaches after target vehicle speed, P, I parameter are less, so that moment of torsion is comparatively steady, finally reach the operating mode of the speed of a motor vehicle smooth operation of target.

By the technical program, under the operating mode of ramp, can actv. solve hill start and slip the problem on slope.Through actual verification, on 30% ramp, utilize this programme can avoid ramp to slip slope problem, thereby make do not increasing under the prerequisite of cost at battery-driven car, meet European relevant criterion, improved safety and the traveling comfort of product.

Accompanying drawing explanation

Fig. 1 electronlmobil prevents that hill start from slipping slope control system figure

Fig. 2 prevents that hill start from slipping slope control principle drawing

Fig. 3 enables condition judgment diagram of circuit

The specific embodiment:

Below in conjunction with accompanying drawing 1, Fig. 2 and Fig. 3, describe specific embodiment of the invention process in detail:

Referring to Fig. 1, the control system figure that slips from electronlmobil prevents hill start can find out, entire car controller is to be risen respectively and obtained corresponding signal from abs controller, Das Gaspedal, brake pedal, shift handle by various sensings, then by following judgement method of calculating, finally send motor torque command to electric machine controller, control motor operation.

Referring to Fig. 1 and Fig. 3, specifically control step as follows:

1, entire car controller (VCU) first provides according to Das Gaspedal aperture, brake pedal information, gear information, motor speed, ABS the speed of a motor vehicle and complete vehicle fault state, judging whether the residing state of car load should enter prevents from slipping slope master mode, and enables torque arithmetic module; Be that entire car controller (VCU) receives after signal, according to the various sensor signals of car load, the condition that judgement enters this pattern comprises:

A, motor speed do not enable during from slow speed of revolution rising 1400rpm, from high rotating speed, decline, and during lower than 1200rpm, enable;

B, brake pedal are not stepped on;

C, shift signal are D gear or R gear;

D, do not have car load to forbid the fault of moment of torsion output;

E, there is no cell safety fault.

2, when whole vehicle state allows to enter while preventing from slipping slope master mode, entire car controller (VCU) starts to calculate target vehicle speed, in starting, target vehicle speed V_Target is constantly 0-8km/h, being certain slope (as 2s) increases, to 8km/h, be stable objects value, to guarantee the steady of the speed of a motor vehicle of starting to walk.

3, the actual vehicle speed V_Act of ABS feedback sends to entire car controller (VCU).

4, entire car controller calculates the difference (Delta_V) of target vehicle speed and actual vehicle speed, thereby carries out the closed loop PI control of moment of torsion.

5, the torque Tq=P*Delta_V+I*Delta_V of actual output.

Wherein, P item is reconcilable parameter, according to the speed of a motor vehicle, proofreaies and correct, and under D blend stop part, when the speed of a motor vehicle is less or be negative value, P item parameter is larger; When the speed of a motor vehicle approaches with 8km/h, P item parameter is less.

I item is reconcilable parameter, according to the speed of a motor vehicle, proofreaies and correct, and under D blend stop part, when the speed of a motor vehicle is less or be negative value, I item parameter is larger; When the speed of a motor vehicle approaches with 8km/h, I item parameter is less.

Claims

1. pure electric automobile prevents the torque control method slipping after hill start, and it comprises the following steps:

(1) entire car controller (VCU) first provides according to Das Gaspedal aperture, brake pedal information, gear information, motor speed, ABS the speed of a motor vehicle and complete vehicle fault state, judging whether the residing state of car load should enter prevents from slipping slope master mode, and enables torque arithmetic module;

Judgement enters and prevents from slipping slope master mode and need possess following condition simultaneously:

A, motor speed do not enable when slow speed of revolution rises to rotating speed A, from high rotating speed, decline, and during lower than rotating speed B, enable;

B, brake pedal are not stepped on;

C, shift signal are D gear or R gear;

D, do not have car load to forbid the fault of moment of torsion output;

E, there is no cell safety fault;

(2) when whole vehicle state allows to enter while preventing from slipping slope master mode, entire car controller (VCU) starts to calculate target vehicle speed, and in starting, target vehicle speed V_Target is constantly 0-8km/h, and be slope and increase up, to 8km/h, be stable objects value;

(3) by ABS feedback actual vehicle speed V_Act, send to entire car controller (VCU);

(4) entire car controller calculates the difference Delta_V of target vehicle speed and actual vehicle speed, thereby carries out the closed loop PI control of moment of torsion;

(5) actual output torque Tq=P*Delta_V+I*Delta_V; P, I parameter by demarcating and obtain under different motor speeds.

2. pure electric automobile according to claim 1 prevents the torque control method slipping after hill start, it is characterized in that: described rotating speed A is 1400rpm, and rotating speed B is 1200rpm.

3. pure electric automobile according to claim 1 and 2 prevents the torque control method slipping after hill start, it is characterized in that: described P item is reconcilable parameter, according to the speed of a motor vehicle, proofread and correct, under D blend stop part, when the speed of a motor vehicle is less or be negative value, P item parameter is larger, and when the speed of a motor vehicle approaches with 8km/h, P item parameter is less; I item is reconcilable parameter, according to the speed of a motor vehicle, proofreaies and correct, and under D blend stop part, when the speed of a motor vehicle is less or be negative value, I item parameter is larger, and when the speed of a motor vehicle approaches with 8km/h, I item parameter is less.