摘要
为提高分布式驱动电动汽车的横向稳定性,提出了一种新的直接横摆力矩控制方案。该方案采用分层控制结构,由上层控制器和下层控制器组成。在上层控制器设计了一种改进指数趋近律的滑模控制器,用于计算维持车辆横向稳定性所需的附加横摆力矩。改进的指数趋近律通过添加关于滑模面函数的方式,在远离滑模面时,增加趋近速度;接近滑模面时,减小趋近速度,以此来抑制抖振现象。在下层控制器中提出了一种基于优化的转矩分配方式,采用多元宇宙优化算法,以最小化轮胎利用率为目标函数,对转矩进行计算并最优地分配到各个轮内电机。Carsim和Simulink联合仿真表明,高速高附着路面,横摆角速度跟踪误差由6.4%降低到2.7%,质心侧偏角范围在0.018 rad以内;低速低附着系数路面,横摆角速度跟踪误差由5.2%降低到3.8%左右,质心侧偏角范围在0.0085 rad以内。与基于规则分配的策略相比,所提出的策略有更好的稳定性。
A novel direct yaw-moment control scheme is proposed to improve the lateral stability of distributed-drive electric vehicles(DDEV).The scheme adopts a hierarchical control structure that consists of an upper controller and a lower controller.An enhanced sliding mode controller(ESMC)with improved exponential reaching law is designed to calculate the additional yaw-moment to maintain the lateral stability of the vehicle in the upper controller.By adding the function about the sliding mode surface,the approach speed is increased when it is far away from the sliding mode surface,and the approach speed is reduced when it is close to the sliding mode surface,so as to suppress chattering.An optimized method of torque distribution is proposed in the lower controller,which uses a multi-verse optimizer(MVO)to minimize the tire utilization rate as the objective function to calculate the torque and optimally distribute it to each in-wheel motor.The co-simulation of Carsim and Simulink shows that under the conditions of high speed and high-adhesion road,the tracking error of the yaw rate is reduced from 6.4%to 2.7%,and the sideslip angle is within 0.018 rad;under the conditions of low speed and low-adhesion road,the tracking error of the yaw rate is reduced from 5.2%to 3.8%,and the sideslip angle is within 0.0085 rad.The proposed strategy has better stability compared with the rule-based distribution strategy.
作者
黄亚东
武小兰
白志峰
HUANG Yadong;WU Xiaolan;BAI Zhifeng(School of Mechanical and Electrical Engineering,Xi’an University of Architecture and Technology,Xi’an 710311,China)
基金
National Natural Science Foundation of China(No.51405367)。
关键词
分布式驱动电动汽车
横向稳定性
滑模控制
多元宇宙优化算法
转矩分配
distributed-drive electric vehicles(DDEV)
lateral stability
sliding mode controller(SMC)
multi-verse optimizer(MVO)
torque distribution
