A Decoupling Control Scheme for Path Tracking with Model Predictive Path Integral and Output Regulator

The coupling and nonlinearity of vehicle dynamics present considerable challenges to path tracking of autonomous vehicles. In this paper, a necessary condition is derived to decouple the translational motion from yawing motion based on the time-scale separation. Consequently, the translational motion is regulated over an extended control horizon to generate a human-like tracking trajectory. The yawing motion is regulated based on a high-fidelity control model. In addition, model predictive path integral (MPPI) is developed to mitigate the computational burden of nonlinear motion planning through sampling-based optimization. A predictive output regulator is developed to solve the underactuated problem in the 2-DOF lateral dynamics with only 1-DOF of control input. Simulation results show that the proposed method enhances computing efficiency and reduces the lateral jerk by an average of 50% with only one set of parameters.