Braking force distribution method of electromobile

Abstract

The invention discloses a braking force distribution method of an electromobile, and belongs to the field of electromobiles. In order to solve the problems that when the electromobile brakes on a pavement of a low attachment coefficient, a motor is controlled to reduce energy recovery, the control complexity is increased, and the safety of the electromobile is reduced, the method is provided. Themethod comprises the following steps that according to braking intensity, the brake force of front and back wheels is distributed; the brake intensity, battery SOC and the total demand brake force aretaken as input, and the proportion of regenerated braking force to front-wheel braking force is output through a fuzzy controller; the regenerated braking force is subtracted from the front-wheel braking force, and friction braking force born by front wheels is obtained; a slip rate threshold value is set, the actual slip rate is taken as input, through backstepping control, the proportion of theregenerated braking force is reduced, and when the actual slip rate exceeds a required slip rate, the braking quota distributed to a driving motor is reduced through backstepping control; according to the method, on the pavement of the low attachment coefficient, energy recovery can be provided as much as possible, and the safety of the electromobile can be kept.

Description

technical field [0001] A method for distributing braking force of an automobile belongs to the field of electric vehicles, and in particular relates to a method for distributing braking force of an electric vehicle. Background technique [0002] Because existing automobiles use mechanical friction for mechanical braking, electric vehicles can use inertial drive to make the motor work in the power generation state. In this state, the braking torque provided by the motor can reduce part of the mechanical braking. Although the braking torque provided by the motor is not a mechanical brake, it can also form the friction between the wheel tire and the ground and provide the effect of deceleration braking force to the electric vehicle. At present, the energy recovery control strategy mainly adopts fuzzy controller, which takes the battery state of charge SOC, total demand braking force and braking intensity as input, and the output is the ratio of regenerative braking. The distri...

AI Technical Summary

Problems solved by technology

However, when electric vehicles brake on roads with low adhesion coefficient (water, ice and snow), since most of the braking force is provided by regenerative braking force, the wheels are prone to lock-up, and the traditional anti-lock braking system of electric vehicles will reduce mechanical braking. Power, at this time, control the motor to reduce energy recovery, which increases the complexity of control and reduces the safety of electric vehicles

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