Torque control method for electric creeping starting of pure electric vehicle

Abstract

The invention discloses a torque control method for electric creeping starting of a pure electric vehicle. The torque control method for electric creeping starting of the pure electric vehicle comprises the following steps that S1, a vehicle controller receives a vehicle speed signal, a longitudinal acceleration signal, and a brake master cylinder pressure signal; S2, benchmark electric creeping torque N<1>is obtained according to vehicle speed table look-up, and the vehicle controller calculates the current road grade beta based on the longitudinal acceleration signal; S3, based on the road grade, and combined with a current vehicle speed, road grade compensation torque N<2> is obtained through torque analysis software; S4, change rate of the brake master cylinder pressure within time iscalculated for judgment to determine an electric creeping starting torque coefficient K; and S5, according to the benchmark electric creeping torque N<1>, the road grade compensation torque N<2> and the electric creeping torque coefficient K, the real-time electric creeping torque N of the pure electric vehicle is calculated, and N is equal to (N<1>+N<2>)* K. Decision-making and judgment can be made in a more humanized mode, the vehicle starting is more controllable, the vehicle starting is smooth and predictable, the problem of rotor-locking and heating of a driving motor during the electriccreeping starting is solved, and the driving comfort is improved.

Description

technical field [0001] The invention relates to the technical field of pure electric vehicles, in particular to a method for controlling electric creep starting torque of pure electric vehicles. Background technique [0002] After nearly 10 years of research and development of new energy vehicles in my country, great progress has been made, and the market acceptance is getting higher and higher. At present, new energy sources mainly include pure electric, hybrid and plug-in hybrid. When a traditional vehicle starts, the torque is transmitted to the wheel ends through the hydraulic torque converter, and the hydraulic torque converter has the effect of energy absorption and shock absorption, so that the driver can control the starting of the vehicle better, and the starting response of the vehicle is smooth And it is predictable, starting on a slope will avoid slipping to a certain extent. [0003] However, ordinary pure electric vehicles transmit torque through a simple sin...

AI Technical Summary

Problems solved by technology

The disadvantage of this approach is that the vehicle does not have electric creep torque while the driver releases the brake pedal

After the brake pedal is released, the response of the electric creep torque is lagging, the acceleration is relatively abrupt, and the driver's controllability is poor

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