To improve handling and stability for distributed drive electric vehicles (DDEV), the study on four wheel steering (4WS) systems can improve the vehicle driving performance through enhancing the tracking capability to desired vehicle state. Most previous controllers are either a large amount of calculation, or requires a lot of experimental data, these are relatively time-consuming and laborious. According to the front and rear wheel steering angle of DDEV can be distributed independently, a novel controller named internal model controller with fractional-order filter (IMC-FOF) for 4WS systems is proposed and studied in this paper. The IMC-FOF is designed using the internal model control theory and compared with IMC and PID controller. The influence of time constant and fractional-order parameters which is optimized using quantum genetic algorithms (QGA) on tracking ability of vehicle state are also analyzed. Using a production vehicle as an example, the simulation is performed combining Matlab/Simulink and CarSim. The comparison results indicated that the proposed controller presents performance to distribute the front and rear wheel steering angle for ensuring better tracking capability to desired vehicle state, meanwhile it possesses strong robustness.

为了提高分布式驱动电动汽车 (DDEV) 的操控性和稳定性，四轮转向 (4WS) 系统的研究可以通过增强对所需车辆状态的跟踪能力来提高车辆的行驶性能。以往的控制器要么计算量大，要么需要大量的实验数据，这些都比较费时费力。针对DDEV前后轮转向角可以独立分配的特点，本文提出并研究了一种新型的4WS系统控制器，称为带分数阶滤波器的内模控制器（IMC-FOF）。IMC-FOF 是利用内模控制理论设计的，并与 IMC 和 PID 控制器进行了比较。还分析了使用量子遗传算法(QGA)优化的时间常数和分数阶参数对车辆状态跟踪能力的影响。以生产车辆为例，结合 Matlab/Simulink 和 CarSim 进行仿真。比较结果表明，所提出的控制器具有分配前后轮转向角的性能，以确保对所需车辆状态的更好跟踪能力，同时具有很强的鲁棒性。