Torque control method and device of electronic power-assisted braking system

Abstract

The embodiment of the invention discloses a torque control method and device of an electronic power-assisted braking system. The system involves an electric control unit, a motor, a brake demand inputunit and a brake force generation unit, wherein the electric control unit is connected with the motor, the brake demand input unit comprises a brake pedal and a pedal travel sensor connected with theelectric control unit, the brake force generation unit comprises a rack, a piston and a brake fluid, and the rack is connected with the motor and the piston. The method comprises the steps that pedalopening information is received, and basic target torque of the motor is calculated according to pedal opening degree information; the actual environment temperature is obtained, and the compensationtarget torque of the motor is determined according to the actual environment temperature; the final target torque of the motor is calculated according to the basic target torque and the compensationtarget torque; and a torque control signal is sent to the motor according to the final target torque, and the motor is controlled to drive the rack to push the piston to move according to the torque control signal. According to the scheme, the actual brake deceleration and the braking deceleration requirement of the vehicle at different temperatures are consistent.

Description

technical field [0001] Embodiments of the present invention relate to automotive electronic power-assisted braking technology, in particular to a torque control method and device for an electronic power-assisted braking system. Background technique [0002] The automobile electronic power-assisted braking system realizes automobile braking by controlling the torque of the motor, which has a better braking effect. [0003] The principle of realizing vehicle braking through torque control is: the controller of the electronic braking system obtains the driver's braking deceleration demand according to the driver's pedaling state transmitted by the pedal sensor in real time, and calculates the target of the motor according to the braking deceleration demand Torque, by sending a target torque control command to the motor, the motor drives the rack to push the piston to move, thereby realizing the output and return of the brake fluid, that is, to realize the pressure building and ...

AI Technical Summary

Problems solved by technology

[0004] However, when the ambient temperature changes, the friction between the rack and the motor shaft changes, and the resistance changes caused by the fluidity of the brake fluid at different temperatures make the actual brake pressure different from the required target brake pressure. As a result, the actual braking deceleration of the vehicle is inconsistent with the driver's braking deceleration demand, which makes the driver's pedal feel worse

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