基于MPC的车道保持系统转向控制策略

针对汽车的自动车道保持系统,研究了基于模型预测控制(MPC)的转向控制策略.对车辆的侧向动力学和轮胎的侧偏特性进行分析,研究了以位移偏差、横摆角偏差和两者微分项为状态变量、前轮转向角为控制输入的侧向动力学模型;在该模型的基础上,建立了车道自动保持控制的优化性能指标和系统约束,引入了平滑的期望参考轨迹,设计了基于MPC的转向控制策略.仿真试验证明,在不同车速下,该控制策略均能迅速消除侧向位移偏差和横摆角偏差,保证车辆沿着车道中心线行驶,并有效平滑系统的动态响应,具有较好的适应性和鲁棒性.

Steering Control for Lane Keeping System Based on MPC

In this paper, steering control based on the model predictive control (MPC) framework was investigated for vehicle automatic lane keeping system (ALKS). First, vehicle lateral dynamics and tire cornering properties were analyzed. The lateral distance error, yaw angle error and the derivates were chosen as the state vector, the steering angle for the front wheel was considered as the control input, and the state space model was developed. Based on the model, the performance index and system constraints for ALKS were established, the smooth desired reference trajectories were introduced, and the MPC control strategy was designed for steering control. Simulation experiments show that the control algorithm eliminates the lateral distance error and yaw angle error quickly, guarantees that the vehicle moves along the center of the lane, smoothes the dynamical responses, and performs well in adaptability and robustness at different speeds.