8轮分布式电驱动车辆AFS和DYC协同控制

Coordinated Control of AFS and DYC for 8-wheel Distributed Electric Drive Vehicle

为提高8轮分布式电驱动车辆动力学综合控制性能,提出一种主动前轮转向系统(AFS)和直接横摆力矩系统(DYC)协同控制方法。首先,基于车辆模型求得考虑垂直载荷转移和侧倾稳定性的期望横摆角速度和质心侧偏角。其次,提出一种联合双线法和横摆角速度法的β-β̇相平面区域划分方法,将车辆状态划分为稳定域、临界稳定域和非稳定域。然后,设计包含决策层、协调控层和转矩分配层的控制器。在决策层,采用改进滑模函数设计附加横摆力矩滑模控制器和附加转角滑模控制器。在协调控制层,根据车辆状态所处的相平面区域设计3种控制策略。在转矩分配层,根据各轴的垂直载荷比例分配各轮转矩。最后,基于MATLAB/Simulink和Trucksim联合仿真平台,进行双移线跟踪试验验证。结果表明,所提控制方法具有较好的轨迹保持精度和车身姿态修正能力,能有效提高车辆的行驶稳定性。

In order to improve the overall dynamic control performance of 8-wheel distributed electric drive vehicle,a coordinated control method of active front-wheel steering system(AFS)and direct yaw moment system(DYC)is proposed.Firstly,the expected yaw velocity and centroid sideslip angle considering vertical load transfer and roll stability are obtained based on the vehicle model.Secondly,a method of phase plane region division method combining the two-line method and yaw method is proposed to divide vehicle states into stable region,critical stable region and unstable region.Then,the controller including the decision-making layer,coordination control layer and torque distribution layer is designed.In the decision-making layer,the improved sliding mode function is used to design additional yaw moment sliding mode controller and additional angle sliding mode controller.In the coordination control layer,three control strategies are designed according to the phase plane region of the vehicle state.In the torque distribution layer,each wheel torque is distributed according to the proportion of the vertical load of each axis.Finally,based on MATLAB/Simulink and Trucksim co-simulation platform,the double-shift tracking experiment is verified.The results show that the proposed control method has good trajectory keeping accuracy and vehicle status correction ability,and can effectively improve the driving stability of the vehicle.