自动驾驶4WS车辆路径跟踪最优控制算法仿真

针对自动驾驶车辆高速主动转向工况下传统的控制算法的控制效果容易出现较多的超调量和较长调节时间的问题,提出了基于车辆动力学模型的轨迹预测跟踪主动转向控制算法,并基于轮胎侧偏刚度非线性的特性设计了权系数线性最优二次型(LQR)后轮转角控制算法,通过联合仿真对控制算法效果进行了验证。仿真结果表明:自动驾驶四轮转向车辆在低、高速工况下进行自主换道行驶时,算法控制效果满足汽车操纵稳定性要求,且权系数LQR后轮转向算法比定侧偏刚度的LQR线性控制算法有更优越的操控性能。

Simulation of Optimal Control Algorithm for Automatic Driving 4WS Vehicle Path Tracking

Aiming at the problem that the control effect of the traditional control algorithm in the high-speed active steering condition of the self-driving vehicle is prone to overshoot and longer adjustment time, the control algorithm for trajectory prediction and tracking active steering based on the vehicle dynamics model is proposed. Based on the nonlinearity of the tire’s cornering stiffness, the linear optimal quadratic(LQR) rear wheel angle control algorithm was designede. The effect of the control algorithm was verified through joint simulation. The simulation results show that the algorithm control effect satisfies the requirements of vehicle steering stability when the self-driving four-wheel steering vehicle performs autonomous lane change under low and high speed conditions, and the weight coefficient LQR rear wheel steering algorithm has better maneuvering performance than the LQR linear control algorithm of the fixed side stiffness.