Control method and control system based on hill descent control system and electric vehicle

Abstract

The invention relates to the field of motor control, and discloses a control method based on a hill descent control (HDC) system, the HDC system and an electric vehicle. The control method comprises:judging the state of the HDC system; under the condition that the HDC system is in a triggered state, determining a target braking torque based on a current speed of the electric vehicle and a targetspeed; comparing a target braking torque with a current maximum braking torque of a motor; and controlling the electric vehicle to brake through a motor feedback brake mode or a motor feedback and hydraulic hybrid brake mode according to a comparison result, and determining that the HDC system is in a trigger state under the condition that a trigger condition is met, wherein the HDC system is in astandby state, the depth signals of the accelerator pedal and the brake pedal are 0, the vehicle speed is within a preset speed range, and the electric vehicle is in an acceleration downhill state. According to the control method, the gradient sensor is not needed to collect the gradient, so that the abnormal HDC function caused by the abnormal signals collected by the gradient sensor can be prevented, and the stability of the braking system and the braking safety of the whole vehicle are greatly improved.

Description

technical field [0001] The invention relates to the field of motor control, in particular to a control method based on a steep slope descent control system, a control system and an electric vehicle. Background technique [0002] The basic principle of the steep slope descent function of traditional engine models is to combine the engine brake and the anti-lock braking system (ABS) to make the vehicle maintain a low speed when going down a steep slope without losing the grip of the tires. Gear box down to 1 gear, can reach low speed driving state. Taking the Land Rover car series as an example, the upper limit speed set for steep slope descent is 9km / h. [0003] But at present, when triggering the steep slope descent function, mainly rely on the electronically controlled hydraulic braking system for friction braking. This braking method has the following problems: (1) Due to the excessive wear of the braking system, the maintenance cost increases High and harmful dust gener...

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Problems solved by technology

[0003] However, at present, when triggering the steep slope descent function, the electronically controlled hydraulic braking system is mainly used for friction braking. This braking method has the following problems: (1) Due to the excessive wear of the braking system, the maintenance cost increases High and harmful dust generation; (2) long-term braking causes thermal decay of the brake disc, resulting in reduced braking performance or even failure; and (3) inertia of the brake medium and complex brake pipelines make the brake response sluggish

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