基于特殊工况制动失效的摩擦片间隙自动补偿控制方法研究

Research on Automatic Compensation Control Method of Friction Liner Clearance on Brake Failure Issue un⁃der Special Operating Conditions

车辆经过特殊行驶工况后易出现制动效能下降或“一脚无制动”问题,其发生机理是车辆制动器卡钳活塞在特殊行驶工况受侧向振动加速度作用出现回退,制动主缸随制动过程所提供的制动液量不足以弥补消除卡钳活塞与摩擦片、摩擦片与制动盘间隙所需液量而引发,其根本原因是卡钳活塞滑动阻力偏小。区别于常规控制活塞滑动阻力措施,提出一种基于轮胎半径与轮胎频谱分析、工况识别及周期性主动加压的消除卡钳活塞、摩擦片及制动盘间隙的自动补偿控制方法,使制动卡钳处于正常或有利于紧急制动的位置,抑制因工况恶劣导致的卡钳活塞回退量大、空行程长引发的制动失效问题。

Certain vehicles encounter decreased braking efficiency or"brake failure at first pedal press"issue after undergoing special driving conditions.The mechanism is that the caliper pis⁃tons of the vehicle's brake system may retract under the influence of lateral vibration acceleration dur⁃ing special driving conditions.The amount of brake fluid provided by the master cylinder during the braking process is insufficient to compensate for the fluid required to eliminate the gap between the caliper piston and the friction pad,as well as the gap between the friction pad and the brake disc,leading to the root cause of the issue which is low sliding resistance of the caliper piston.Different from conventional measures to control the sliding resistance of the piston,a method for automatic compensation control based on tire radius and tire frequency spectrum analysis,driving condition rec⁃ognition,and periodic active pressurization is proposed to eliminate the gap between the caliper pis⁃ton,friction pad,and brake disc.This method ensures that the brake caliper is in a normal position or in a position favorable for emergency braking,suppressing brake failure issues caused by large caliper piston retraction and long free stroke due to harsh driving conditions.