分布式驱动电动汽车动力转向系统混杂系统动力学及其切换控制

分布式驱动电动汽车是燃油汽车和电动汽车过渡的一种新型新能源汽车,动力转向系统(ECIPS) 作为电动化底盘集成控制系统(ECIS)的主要组成部分,对电动汽车的设计与装配具有重要的影响. 动力转向系统具有典型的不确定性、未建模动态、测量噪声和干扰等非线性动力学特征,是包含离散事件与连续事件的混杂动力学系统. 分析了分布式驱动电动汽车动力转向系统的控制结构、控制功能及其动力学行为,基于动力转向系统的输入/输出功能、控制状态和控制系统实现流程,建立了反映连续和离散控制行为的混杂控制系统模型. 建立了动力转向系统的混杂控制流程和切换控制结构,进行了25km/h和45km/h下的蛇形实验. 结果表明：在25km/h下,转向系统转矩的峰值和平均值分别降低了41.68%和41.79%, 在45km/h下,转向系统转矩的峰值和平均值分别降低了30.92%和30.67%,转向轻便性得到明显改善.混杂系统动力学模型及其混杂控制结构反映了分布式驱动电动汽车动力转向系统的动力学行为及其控制特征,不仅揭示了动力转向系统的连续系统工作行为,也反映了离散事件特征,对分布式驱动电动汽车控制性能的改善、智能化水平的提高提供了理论研究意义和工程研究价值.

Hybrid Control Dynamics and Switching-control of Power Steering System for Distributed Electric Drive Vehicle

Distributed electric drive vehicle is a new type of new energy vehicle which fills the gap between the conventional internal-combustion engine vehicle and the electric vehicle. Power Steering System (ECIPS) system, as a important parts of Electric Chassis Integrated System (ECIS), is one of the key parts of distributed electric drive vehicle in their design and assembly. ECIPS system was not only a complex nonlinear dynamic system with uncertainty, unmodeled dynamics, measurement noise and interference, but a hybrid system including both discrete event and continuous dynamics. The structure, control function and dynamic behavior of ECIPS system was analyzed. Based on its input/output functions, operating conditions and implementation process of control strategy, the implement model structure reflecting both the discrete and continuous dynamic behavior of ECIPS hybrid system was established. The switching-control of ECIPS hybrid system and its stateflow was established. The pylon course slalom test was executed under 25km/h and 45 km/h speed condition respectively. The results show that the peak vaule and standard deviation of steering torque were reduced by 41.68% and 41.79% respectively when 25km/h speed, and by 30.92% and 30.67% respectively when 45km/h speed, the steering portability is improved obviously. ECIPS hybrid control system and its hybrid structure could fully describe the dynamic behavior and operating characteristics of ECIPS system, reflecting not only the continuous dynamic behavior, but the influence of discrete dynamic behavior on its operation, monitoring, security and liability. It was of theoretical significance and engineering application prospect to the Electric Chassis Integrated System for improving control performance, intelligent level and making the system more approachable to users.