Research On The Path Planning And Lateral Control Of The Intelligent Vehicle’s High-speed Lane-changing

With the continuous development of automobile technology,automobile intelligence has gradually become a new trend of industry development.Intelligent driving technology has received extensive attention in recent years,and more and more research work has been carried out around it.Lane change is the most common behavior in vehicle driving.There are many traffic accidents caused by changing lanes in the process of driving vehicles,so how to use intelligent driving technology to make vehicle traffic change more efficient and safe has gradually become a hot issue in recent years.In this paper,the path planning and lateral tracking control of driverless vehicles in expressway scene are studied.For different change of roads An effective path planning method is proposed,and a path tracking controller is designed to complete the lane change control of the vehicle.This paper mainly includes the following five aspects of research:(1)According to the main characteristics of expressway and the basic characteristics of driver’s lane change behavior,the strategy of lane change is formulated from the point of view of lane change intention,and the minimum safe distance of lane change effective space is given.(2)On the premise of having lane change space,the vehicle lane change path is planned by using the fifth polynomial.By optimizing the setting of the objective function and introducing the vehicle dynamics constraint,the optimization problem is solved to obtain the shortest lane change path under the vehicle dynamics constraint.(3)Combined with the characteristics of the vehicle in the highway scene,and based on the reasonable assumption,the vehicle monorail model and the magic formula tire model are established,which lays the foundation for the design of the subsequent model prediction controller.(4)The nonlinear vehicle dynamics model is linearized and the optimization objective function is set.In order to improve the stability of vehicle tracking control at high speed,vehicle dynamics constraints are introduced.Furthermore,a model predictive controller for high speed channel switching transverse tracking control is designed.The CarSim/Simulink joint simulation platform is built to verify the effectiveness of the algorithm,which is based on the multinomial switching path as the reference path.The results show that the path tracking controller based on model predictive control can complete the lane change and maintain the stability of the vehicle under different pavement attachment conditions and different vehicle speeds.(5)The obstacle avoidance principle of repulsive force field based on artificial potential field algorithm is used to model the changing space and road in the decision mechanism of high speed lane change.The safe distance of the changing lane is introduced into the design range of the repulsive force field,which ensures that there is enough space for the vehicle to change lanes.The road potential field modeling ensures the rationality of the vehicle path in the process of changing lanes.The established potential field function is brought into the framework of the simplified model prediction algorithm to solve,and the path information is passed into the control layer for switching control.It is solved in the simulation platform of CarSim/Simulink,and the feasibility of the algorithm is verified and analyzed.The results show that the algorithm can be used.On the premise of considering the collision avoidance with adjacent vehicles in the process of changing lanes,and the process of changing lanes is stable,compared with the method based on quintic multinomial,the safety and reliability of lane switching are improved.