分布式全线控电动汽车的底盘集成控制

Integrated Chassis Control of Distributed Drive-by-Wire Electric Vehicles

针对分布式全线控电动汽车四轮独立驱动/独立制动/独立转向的结构特点,提出一种基于分层架构的底盘集成控制策略.该策略包括参考目标设定、集成控制层以及控制分配层3个主要部分.参考目标设定主要实现驾驶员操作信息与车辆控制目标的转换,从车辆水平方向上可以划分成纵向加减速特性和侧向操纵稳定性;集成控制层利用具有反馈校正特征的模型预测控制方法实现对整车控制力和力矩的多目标优化;控制分配层以各车轮轮胎负荷率最低为优化目标,实现对各车轮驱动力矩和车轮转角的分配.从仿真分析和实车低速工况验证的结果来看,所提出的底盘集成控制策略能够使车辆在实际行驶时较好地跟踪参考目标,并通过控制各轮胎负荷率近似相等来提高车辆的稳定性.

In view of the characteristics of distributed drive-by-wire electric vehicles with four-wheel drive / brake /steering independently,an integrated chassis control strategy is proposed on the basis of layered architecture. The strategy mainly includes three parts,namely,reference targets setting,integrated control layer and control allocation layer. The reference target setting is aimed to realize the conversions from the driver's operations to the control targets of vehicle,and the control targets in the horizontal direction of vehicle are divided into longitudinal acceleration or deceleration features and lateral handling and stability. The role of integrated control layer is to achieve the multi-objective optimization of vehicle control force and moment by means of model prediction control( MPC),which is a kind of local optimization algorithm of feedback correction features. The control allocation layer is used to realize the allocation of driving forces and the steering angles of wheels by minimizing the tire load ratio of each wheel. The results of the simulations and the validations on the real vehicle at a low speed indicate that the proposed strategy can help the vehicle to track the references quickly and improve the stability of vehicle by adjusting the negative rate of each wheel to be approximately equal.