Study on TTC-based optimal lane change algorithm in adaptive cruise control

Abstract

The advanced driver assistance system for autonomous vehicles is being researched and developed for driving stability and driver convenience. Autonomous driving systems, such as adaptive cruise control(ACC), lane keeping assistance(LKA), and lane change system(LCS), have been developed, and they are being applied to many vehicles. The most important goal of these advanced control systems is to improve safety. In this paper, we propose an optimal lane change controller while considering the crash risk by using the information of the preceding vehicle and the side lane vehicle for a safe lane change. The optimal controller for the lane change is designed by using the vehicle state space model. Furthermore, the time-to-collision(TTC), which is a risk index, is applied to the optimal controller. We compared the simulation result of the TTC-based optimal controller with that of the optimal controller by using a constant weighting factor. The optimal controller was developed in Matlab/Simulink, and the vehicle dynamics simulator, CarSim, was used for controller verification and comparison of results.