设计一种力与位移耦合控制的前轮主动转向(Active front steering,AFS)系统,使其同时具有主动转向和电动助力转向功能,不仅实现汽车转向轻便性和转向路感的完美融合,而且实现汽车安全性与灵活性的协调统一,是一种理想的汽车动力转向技术。建立新型AFS系统和整车3自由度动力学模型,提出新型AFS系统的性能指标及量化公式,应用协同优化方法,考虑人机工程学、汽车安全性和转向经济性三个子系统,以转向路感为系统级优化目标,对新型AFS系统参数进行协同优化设计。仿真结果表明,基于协同优化的新型AFS系统可在保证系统具有较好的转向稳定性、转向灵敏度和转向能耗基础上,有效提高系统的转向路感,为新型AFS系统的设计和优化提供理论基础。
The dynanaic model of a novel electric power steering（EPS） system integrated with active front steer- ing function and the three-freedom steering model are built. Based on these models, the concepts and the quanti- tative expressions of road feel, sensitivity, and operation stability of the steering are introduced. Then, according to constrained optimization features of multi-variable function, a genetic algorithm is designed. Making the road feel of the steering as optimization objective, and operation stability and sensitivity of the steering as constraints, the system parameters are optimized by the genetic and the coordinate rotation algorithms. Simulation results show that the optimization of the novel EPS system by the genetic algorithm can effectively improve the road feel, thus providing a theoretical basis for the design and optimization of the novel EPS system.
