Development and evaluation of driving speed controller for lane merging considering surrounding driver's intention toward stress-free driving

A model predictive controller to perform a lane-merging task is proposed. We consider a hierarchical control structure that consists of an inner and outer control loop. The inner loop is an adaptive cruise controller that gives the acceleration command to the autonomous merging car to follow the designated speed and maintain a relative distance from the preceding vehicle while satisfying the constraints based on explicit optimal control. The outer loop determines the car in the main lane that the autonomous car should follow to maximize the acceptance and clarity of the decision-making of the human drivers in the main lane. The proposed system is implemented on the merging car in a driving simulator, and the human driver evaluates the merging car while driving in the main lane. The validity of the proposed system was determined through objective and subjective evaluations by human drivers.