Recent researches on advanced driver-assistance systems (ADASs) indicate great advances in terms of safety and comfort in automated driving. ADASs use control systems to perform most of the maneuvers as performed by the driver in the past. One of the useful ADASs is automatic lane change system in order to avoid accidents. This study designs the controller of an automatic lane change system for an autonomous vehicle. The control law in this study is Adaptive Sliding Mode Control (ASMC). To avoid chattering in ASMC, fuzzy boundary layer is used. Also, adaptive law is used for sliding-based switching gain. This adaptive controlling law is used to avoid the calculation of upper bound of system uncertainties. In this study, based on the boundary conditions, the vehicle lane change path planning and different maneuver periods are evaluated. To simulate the designed controller, CarSim-Simulink joint simulation model is used. This linkage leads to a full nonlinear vehicle model. The results of simulation show excellent tracking for dry road conditions and acceptable tracking in icy and wet roads in some maneuvers of above 4 seconds long.
Keywords: Autonomous vehicle, Adaptive Sliding Mode Control, Fuzzy logic system, Automatic Lane Change