Study On Multi-mode Switching Of Adaptive Cruise Control And Active Lane Change Of Vehicle

With the continuous upgrading of automotive technology,the Adaptive Cruise Control(ACC)system has gradually moved toward the general public as a longitudinal speed control module for automobiles.However,the conventional ACC system cannot recognize the driver’s intention to change lanes,and cannot change the acceleration of the vehicle during the lane change process for the tracking target.Instead,the original car is still tracked,so that it is impossible to coordinate the two lanes before and after the lane change.Therefore,it is of great significance to carry out research on multi-mode switching of adaptive cruise control and active lane change of vehicle.Firstly,building three degrees of freedom model,the tire model and active steering system model of vehicle for requirements of lane change and ACC control,which lays the foundation for the following chapters.Subsequently,in order to analyze the driver’s lane change behavior,and the intention for lane change was divided.In addition,in order to judge the feasibility and safety of lane change when the driver has the intention of lane change,the safety distance of the front and rear vehicles of the target lane is analyzed.According to the switching of the adaptive cruise tracking target in the course of lane changing,the tracking state of the target before and after lane changing should be different,and the changing state of the target tracking before and after lane changing is divided.And the calculation method of expected acceleration and desired throttle opening is designed for different longitudinal tracking forms.In order to achieve a smooth transition of the tracking target during the lane change process,the acceleration and throttle weight switching methods are designed respectively.After the desired acceleration or throttle opening value is determined from the upper level,the lower controller with longitudinal control is designed to control the vehicle’s longitudinal speed and distance from the vehicle in front.In order to complete the vehicle lane change control,the lane change path is designed first;the desired yaw angle is obtained according to the ideal lane change path,and the sliding mode controller is designed to track the desired yaw angle to obtain the ideal steering wheel angle,so as to track the lane changing path of the vehicle and realize the ACC multi-mode switching control in the process of lane changing.In order to verify the effectiveness of the adaptive cruise control mode switching controller in the process of vehicle lane changing,different working conditions were set by the Carsim and Matlab simulation platforms,and the designed control algorithm was simulated and verified.Finally,the hardware-in-the-loop and real-vehicle test platform is designed and built,and the effectiveness of the adaptive cruise multi-mode switching and active lane change control algorithm is verified through experiments.