Torque control method and device for an electronic power-assisted braking system

Abstract

The embodiment of the present invention discloses a torque control method and device of an electronic power-assisted braking system. The system includes an electric control unit, a motor, a braking demand input unit and a braking force generating unit, the electric control unit is connected with the motor; the braking demand input unit includes a brake pedal and a pedal stroke sensor connected with the electric control unit; the braking force generation unit The unit includes a rack, a piston and brake fluid, and the rack is connected to the motor and the piston, respectively. The method includes: receiving pedal opening information, and calculating a basic target torque of the motor according to the pedal opening information; acquiring an actual ambient temperature, and determining a compensation target torque of the motor according to the actual ambient temperature; calculating the motor's compensation target torque according to the basic target torque and the compensation target torque Final target torque; send a torque control signal to the motor according to the final target torque, and control the motor to drive the rack to push the piston to move according to the torque control signal. This solution realizes that the actual braking deceleration of the vehicle is consistent with the braking deceleration requirement at different temperatures.

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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