Hill starting control method and system of electric vehicle

Abstract

The invention provides a hill starting control method and a system of an electric vehicle, wherein the hill starting control method comprises the steps of: (S1) acquiring gear signals and brake pedal openness signals of the electric vehicle; (S2) judging if the openness of a brake pedal of the electric vehicle is smaller than a first brake pedal openness threshold when the gear of the electric vehicle is located in the gear D or the gear R; and (S3) controlling a motor of the electric vehicle to enter a torque control model when the openness of the brake pedal of the electric vehicle is smaller than the first brake pedal openness threshold for a preset time. The hill starting control method realizes the functions of hill parking and no-slippage hill starting through the locked-rotor characteristic of the motor of the electric vehicle and through the control to the rotating speed and the torque of the motor, and fully uses the power system characteristic of the electric vehicle.

Description

Technical field [0001] The invention relates to the technical field of electric vehicles, and in particular to a ramp-start control method and system for electric vehicles. Background technique [0002] The hill start assist system can effectively prevent the vehicle from slipping back when starting on a hill. This function has played a great role in the humanization of vehicle driving and the reduction of the number of traffic accidents. Traditional cars generally rely on ABS (Anti-lock Braking System) or ESP (Electronic Stability Program, Body Electronic Stability System) to achieve hill start assistance. These systems can provide braking assistance and control the position The opening and closing of the isolation valve between the brake master cylinder and the wheel cylinder to achieve the hill start assist function. [0003] At present, the main methods for realizing the start assist of the car on the ramp are: [0004] (1) ABS-based semi-automatic ramp start assist system [00...

AI Technical Summary

Problems solved by technology

[0008] However, after analyzing the prior art, the inventor found that there are at least the following problems in the prior art: (1) The semi-automatic hill start assist system based on ABS, this method must be based on the electromechanical automatic transmission technology, which requires driving (2) ABS-based active hill start assist system, this method is more complicated in structure, requires additional sensors and other electronic control units, and cannot Leveraging Electric Vehicle Powertrain Characteristics

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