Natural Speed Planning and Control of the Autonomous Vehicle within Social Norm

The tradeoff between strict regulation of autonomous vehicle-driving rules and natural behavior is sufficient to realize autonomous driving technology. However, most autonomous vehicles' control logic is designed to strictly satisfy the driving rules that can sometimes cause car accidents and unnatural behavior. In this study, by relaxing the constraints in the optimization problem, we propose the controller, which makes the autonomous vehicle natural behavior, even though it slightly violates the social norm. The autonomous vehicle sometimes exceeds the road speed limit to pass the traffic light by adding the slack variables to the state and control constraints in the optimization problem, which is similar to the human driver's behavior in front of the traffic light. Our approach shows that autonomous vehicle behaves more natural than conventional techniques. In addition, the overall trip time is decreased, thus minimizing fuel consumption.