基于模糊逻辑的EHB系统制动意图识别

Identification of Braking Intention of EHB System Based on Fuzzy Logic

随着汽车电子技术的发展,线控技术日趋成熟。目前,电子机械制动(EMB)系统尚未成熟,电子液压制动(EHB)系统成为线控制动系统的主力产品。EHB系统取消了制动踏板与制动总泵推杆之间的硬连接,通过传感器测量驾驶员踩制动踏板的参数并传输给电子控制单元(ECU);ECU根据已设定的算法决定助力大小,对驾驶员的制动意图进行识别。基于机械解耦电子液压线控制动系统,提出了一种基于模糊逻辑的驾驶员紧急制动意图识别方法。首先,利用NI-PXI的DAQmx采集卡采集制动踏板的位移,将制动踏板位移对时间求导得到制动踏板速度。然后,将制动踏板位移和速度作为模糊模式识别算法的输入,判断是否为紧急制动意图:如果是紧急制动意图,则制动辅助策略介入;否则制动辅助策略不介入,执行常规制动策略。最后,对汽车在典型工况下的紧急制动意图进行硬件在环,通过对比仿真结果,验证了制动意图识别算法的有效性。该算法为今后EHB系统的制动意图识别提供一定依据,有利于该e Booster系统的产品化。

With the development of automotive electronic technology,the technology of wire control technology has become more and more mature. Because the electro mechanical braking （ EMB） system is not yet mature enough, so the electro hydraulic braking （EHB） has become the major product of the wire controlled brake system. In EHB system, the hard connection between the brake pedal and the brake master cylinder push rod is eliminated ; the parameters related to the actions of driver are measured by sensor and sent to the ECU. According to the established algorithm,the force aided is decided by ECU,while it is necessary to identify the intention of driver. Based on the design of the mechanical decoupling electro hydraulic wire collected control system, the identification method based on fuzzy logic is proposed. Firstly,the displacement of brake pedal is collected by using DAQmx acquisition card of NI - PXI,and the time derivative of the brake pedal is conducted to obtain the velocity of the pedal. Then,the displacement and velocity of the pedal are input to the fuzzy identification algorithm to judge if it is the intention for emergency braking or not, thus to select if the braking aids strategy will be involved or not. Finally, the emergency braking intention of the vehicle under the typical operating conditions is carried out in the hardware, and the simulation results are given to verify the effectiveness of the algorithm. The method provides a basis for the identification of braking intention of EHB system in the future, and is conducive to the production of the eBooster system.