Design and Evaluation of a Driving Mode Decision Algorithm for Automated Driving Vehicle on a Motorway

This paper describes design and evaluation of a driving mode decision algorithm for automated driving on a motorway circumstance. For the development of a highly automated driving control algorithm on a motorway, driving mode decision is necessary to manage the driving condition in various road traffic situations. There are two driving modes; lane keeping and lane change. Desired driving mode is determined by a cost function that considers lane change or deceleration time, acceleration magnitude, and desired speed. A safety driving envelope is defined based on the desired driving mode using information of surrounding vehicles behaviors. To obtain the desired steering angle and longitudinal acceleration for maintaining the subject vehicle in the safe driving envelope, motion planning controller is designed using a model predictive control (MPC) with constraints. The proposed control algorithm has been evaluated via computer simulation studies. Simulation results show that the host vehicle changes its lane with safety guaranteed.