Research On Dynamic Obstacle Avoidance Local Path Planning And Control Of Semi-Truck Train

Semi-trailer trains have made great contributions to the economic development of our country,and will continue to be the main carrier of long-distance cargo transportation in the long future.However,with the increase of the number of semitrailer trains,the number of road traffic accidents of semi-trailer trains has also increased significantly.At present,there is still a lack of research on active driving safety of semi-trailer trains.The main contents of this paper are as follows:1.Build the point mass model and dynamics model of semi-trailer train as the prediction model of model predictive control theory,verify the dynamics model of semi-trailer train by using Trucksim and Simulink software under the conditions of step-angle input and sinusoidal input of steering wheel respectively,and analyze the causes of error.2.For scenes with dynamic obstacles,a design idea of local path planner based on the theory of Nonlinear Model Predictive Control(NMPC)is proposed.Taking the lateral acceleration as the rollover limit condition,the driving paths of semi-trailer cars and obstacle cars are predicted,and the cost function with "far from obstacles","near global path" and "vehicle driving stability" as the optimization objective is constructed.The local path planning of semi-trailer cars is completed by solving the cost function.3.In order to ensure the tracking accuracy of the path tracking controller,the lateral dynamics model of the semi-trailer train with higher accuracy is adopted as the predictive model,and the design idea of the path tracking controller based on the theory of Linear Time Varying Model Predictive Control(LTV MPC)is proposed.4.The local path planner and path tracking controller are integrated,and the real accident cases participated by semi-trailer trains in the national vehicle accident indepth investigation system are simulated and reproduced.The accident simulation scene is constructed by using Trucksim and Simulink software,and the accident is successfully avoided by using the dynamic collision avoidance system established in this paper.Finally,two kinds of road conditions are selected to carry out the test again,which proves the feasibility of the semi-trailer dynamic active collision avoidance system.