Development of an Autonomous Driving Controller for Articulated Bus Using Model Predictive Control Algorithm with Inner Model

This research suggests an autonomous driving control algorithm for Bus Rapid Transit (BRT, articulated bus). The control algorithm is composed of an integration of MPC (model Predictive Control) and PI control algorithms because vehicles have a lot of delayed systems. Specifically, an MPC algorithm is used as a lateral controller, and a PI control algorithm is used as a longitudinal controller in parallel. To develop the MPC algorithm, path information (path planning) and an inner model is necessary. Thus, the path information is defined as the road center since the BRT is traveling a certain path, and the inner model is defined from the bicycle model of vehicle dynamics. The wheel steering input is controlled based on the predicted lateral movement using the inner model. To develop the PI algorithm, brake pressure and throttle position inputs are controlled based on the longitudinal velocity error. As a result, the integrated control algorithm of MPC and PI is developed in commercial tool Matlab/Simulink with a plant model which is developed in commercial tool TruckSim. In conclusion, the integrated control algorithm is verified in the simulation environment with a standard of ISO-11270 which is to test a Lane Keeping Assist System (LKAS).