Trajectory Planning Method for Tractor-trailer System Based on Nonlinear Model Predictive Control

The tractor-trailer system has the characteristics of high state dimension, complex constraints and poor internal stability in trajectory planning. Therefore, this paper proposed a trajectory planning method for tractor-trailer system based on nonlinear model predictive control(NMPC) in static and dynamic environments. Firstly, an NMPC optimization problem is formulated by constructing performance indicators and integrating the constraints of the system. Secondly, an approximate optimal path is found as a reference solution for the warm start of the optimization problem by RRT* sampling in high dimensional state space. Thirdly, the NMPC problem is solved by Optimization Engine (OpEn) efficiently. Finally, simulation in different scenarios demonstrated the effectiveness and efficiency of the proposed method.