Research On Adaptive Cruise Control Strategy With Lane Change Function

Vehicle adaptive cruise control system is one of the key technologies of intelligent vehicles.With the development of intelligent vehicles,autonomous decision making with lane change function of horizontal and vertical integrated ACC control has become an important development direction in the future.This paper studies the adaptive cruise control strategy with lane change function,aiming at realizing the horizontal and vertical integrated ACC system function with lane change function under the condition of urban expressway and expressway.The specific research and work contents of this paper are as follows:Firstly,the horizontal and vertical integrated ACC control system framework with lane change function is determined,and the ACC vehicle controller is designed with a hierarchical structure.In the upper controller,the vehicle longitudinal kinematics model is established,and the MPC controller is designed based on the model predictive control theory to solve the expected acceleration of the vehicle.In addition,the control modes of ACC vehicle are divided into three kinds: constant speed cruise,following cruise and lane changing cruise,and the corresponding switching strategy is designed;In the lower controller,the vehicle driving inverse model and braking inverse model are established to solve the desired throttle opening and braking pressure,and the throttle / braking switching logic is designed.To ensure the stability and accuracy of the lower controller,the simulation test is carried out based on Car Sim / Simulink simulation platform.Then,the lane change decision-making mechanism of ACC vehicles is explained.The cumulative degree of dissatisfaction with speed is used as the reference value to judge whether there is lane change intention,and the minimum safe distance is used as the reference value to judge whether there is a lane change condition.In addition,to effectively carry out relevant research,the vehicle lane change scene is simplified,and the lane change decision mechanism of ACC vehicles is designed.Then,various trajectory planning methods are analyzed and compared,and the fifthdegree polynomial with smooth curvature and simple structure is selected for ACC vehicle lane changing trajectory planning.The vehicle two degree of freedom dynamic model is established,and the MPC trajectory tracking controller is designed based on the model prediction theory.To ensure the stability and accuracy of trajectory tracking,four working conditions are designed and simulated based on Car Sim / Simulink simulation platform.Finally,the autopilot simulation test is briefly summarized,and three types of test conditions are designed.Based on VTD / Car Sim / Matlab / Simulink and NI PXI real-time system,the virtual simulation test platform and semi-physical verification platform are built respectively,and the functions developed in this paper are simulated and verified.The results show that the horizontal and vertical ACC control algorithm and strategy designed in this paper are stable and efficient.