Abstract: To improve braking safety and stability, an optimal braking force distribution strategy for brake-by-wire system of four-wheel independent break based on slip ratio and a real time optimization calculation method for the constrained optimization problem were proposed, and a co-simulation model of Simulink and CarSim was established to simulate and test.The simulation results show that the optimal braking force distribution strategy based on slip ratio may always ensure the front wheel slip ratio greater than the rear wheels' and the rear wheel slip ratio is optimal under different braking conditions,which improves vehicle braking stability and obtains shorter braking distance. At last, the optimal braking force distribution strategy algorithm is verified and it meets the requirements in real-time.

Key words: brake-by-wire system, braking force distribution, slip ratio, co-simulation

摘要： 为提高制动安全性和稳定性，针对四轮独立制动的线控制动系统，提出了基于滑移率的制动力最优分配策略及其约束优化问题的实时求解方法，并建立了Simulink与CarSim的联合仿真实验。仿真结果表明，所提出的制动力最优分配策略在不同的制动工况下始终能保证前轮滑移率大于后轮滑移率且后轮滑移率最优，既提高了汽车制动稳定性又能获得较短的制动距离。最后对最优制动力分配策略算法的实时性进行了实验验证，实验结果表明，所提出算法能够满足控制的实时性要求。

关键词: 线控制动系统, 制动力分配, 滑移率, 联合仿真