一种附着系数实时可调的汽车制动模拟试验台 设计、分析与实验研究

为了实现车辆制动模拟试验中附着系数的准确模拟和实时可调,设计了一种汽车制动模拟试验台,通过控制磁粉离合器励磁电流,实时模拟不同路面附着系数;搭建了基于路面识别的单轮车辆制动系统仿真模型,进行了单一路面和跃变路面下的制动仿真;研制了车辆制动模拟实验系统,开展了单一路面下汽车制动模拟实验和跃变路面下附着系数跟踪控制实验。研究结果表明,在湿沥青路面上以120 km/h初速度制动时,相比于基于固定目标滑移率,基于路面识别的最佳滑移率下的制动距离缩短了3.1%,且在低附着路面下更为明显;单一路面下制动时车速和轮速的实验值与仿真值基本吻合;跃变路面下附着系数最大跟踪误差仅为6.2%,跟踪控制效果良好。

Design, analysis and experiment of an automobile braking simulation test-bench with real-time adjustable adhesion coefficient

In order to realize accurate simulation and real-time adjustment of the road surface adhesion coefficient (RSAC) during vehicle braking simulation test, an automobile braking simulation test-bench (ABSTB) was designed which is capable of simulating different RSACs in real time by controlling the excitation current of an magnetic powder clutch. Then, a simulation model of a single-wheel automobile braking system based on road surface recognition (RSR) was built, and braking simulations were performed under the single road surface and the jumping road surface, respectively. An experimental system for the automobile braking simulation was developed to carry out the automobile braking simulation experiment on a single road surface and the tracking control experiment of the RSAC under the jumping road surface, respectively. Research results show that the braking distance reduces by 3. 1% under the RSR-based optimal slip ratio condition compared with that under the fixed target slip ratio condition for braking on the wet asphalt road surface at an initial speed of 120 km/ h. The phenomenon becomes more obvious under the road surface with a low RSAC. Moreover, experimental values of vehicle speed and wheel speed basically consist with simulation values under the single road surface. The maximum tracking error of the RSAC is only 6. 2% , which proves that the tracking control effect is satisfactory under the jumping road surface condition.