六轮分布式驱动无人车直驶稳定性仿真研究

Simulation Study on the Direct Driving Stability of Six-wheel Distributed Drive Unmanned Vehicle

依据六轮分布式驱动无人车的驱动轮转矩单独可控特点,为降低无人车由于装配误差、各驱动电机驱动差异及不同行驶工况对六轮无人车直线行驶稳定性的影响,设计了六轮无人车直驶稳定控制系统。该系统包含基于滑模控制的附加横摆力矩决策和基于PI控制的驱动防滑系统,确保无人车在保持直线行驶的同时各驱动轮的滑转率不超过最优滑转率。为验证所设计系统的有效性,利用MATLAB/Simulink搭建9自由度无人车模型和直驶稳定性控制系统模型,在对开路面进行仿真验证。结果表明,与无控制的车辆直驶相比,所设计直驶稳定控制系统加入后,无人车的横摆角速度能够控制在理想范围内,且各轮的滑转率都控制在最优滑转率以内,表明该直驶稳定性控制系统能够很好地提高无人车的直驶稳定性。

In order to reduce the influence of assembly error,driving difference of each driving motor and different driving conditions on the straight driving stability of six-wheel distributed driving unmanned vehicle,a straight driving stability control system of six-wheel driverless vehicle is designed according to the individually controllable characteristics of driving wheel torque of six-wheel driverless vehicle.The system includes the additional yaw moment decision based on sliding mode control and the driving anti-skid system based on PI control,which ensures that the slip rate of each driving wheel does not exceed the optimal slip rate while maintaining straight driving.In order to verify the effectiveness of the designed system,the 9-DOF unmanned vehicle model and the straight driving stability control system model are built by using Matlab/Simulink,and the simulation verification is carried out on the opposite road surface.The results show that,compared with the straight driving without control,the yaw angular velocity of the unmanned vehicle can be controlled within the ideal range and the slip rate of each wheel can be controlled within the optimal slip rate after the addition of the designed straight driving stability control system,indicating that the straight driving stability control system can improve the straight driving stability of unmanned vehicle.