基于线控转向的差动转向控制策略研究

Research on differential steering control strategy based on steer-by-wire

针对分布式电驱动整车差动转向问题,文章以线控转向机构作为转向执行机构,研究基于横摆角速度和车辆路径的综合反馈控制策略。采用MATLAB/Simulink和CarSim的联合仿真,设计滑模控制器和线性二次型调节器,重新分配四轮转矩,决策出合理的前轮附加转角,以保证汽车的行驶稳定性,并选取典型工况对控制策略进行仿真验证。仿真结果表明,基于横摆角速度的滑模控制器与基于路径的路径跟踪控制器的综合控制策略,相较于传统基于横摆角速度和质心侧偏角的滑模控制器,车辆实际横摆角速度与理想横摆角速度误差大幅下降;车辆路径与期望路径误差亦得到有效控制。

For differential steering control of the distributed electric drive vehicle,an integrated feedback control strategy based on the yaw velocity and vehicle path is studied using steer-by-wire(SBW)mechanism as steering actuator.Through the co-simulation of MATLAB/Simulink and CarSim,the sliding mode controller and linear quadratic regulator(LQR)are designed,and four wheels torques are redistributed.A reasonable additional front wheel angle is determined to ensure the driving stability of the vehicle.To prove the validity of the control strategy,the simulation is conducted under typical working conditions.The simulation results show that under the integrated control strategy of the sliding mode controller based on yaw velocity and the path tracking controller based on path acquisition,the error between actual yaw velocity and ideal yaw velocity decreases greatly,and the error between vehicle path and expected path is controlled effectively,compared with the traditional sliding mode controller based on yaw velocity and sideslip angle.