Research On Obstacle Avoidance Planning And Tracking Control Of Mine Vehicle Based On Spatial MPC

Automation of coal mining and transportation is the development trend of coal mine in the future,and also an important link to realize intelligent and green mines.Efficient,convenient,reliable and fast personnel and cargo transport capacity is an important basis for improving coal mine safety production efficiency.Therefore,this paper focuses on the key control technology of unmanned mine vehicle-automatic steering control.First,a deviation model based on space domain s is established in Frenet coordinate system.Then the prediction equation based on mine vehicle deviation model is derived by Taylor linearization and Euler method.On the one hand,it can guarantee the accuracy and real-time control,on the other hand,it can ignore the shape influence of the road in Cartesian coordinate system.A path tracking controller based on spatial model predictive control algorithm(SMPC)was designed to solve the problem of the unsmooth curve of the steering Angle of the output front wheel in the course of mine vehicle path tracking.The first and second derivatives of vehicle steering curvature and the lateral displacement deviation are optimized by using the principle of gyroscope,which guarantees the accuracy of vehicle tracking process and the smoothness of output front wheel Angle.Through the simulation experiment,the influence of the parameters of the controller on the tracking performance is analyzed,and the performance difference between the improved SMPC control algorithm and the linear model predictive control algorithm in the doublemoving road and the simulated real roadway is compared.In order to ensure that vehicles can re-plan a barrier-free smooth path according to the reference road in case of emergency in the roadway,a new obstacle avoidance method is proposed,and a local path planning controller based on SMPC is designed on this basis.The design objective function optimizes the transverse deviation value and its first and second derivatives,and sets the boundary function for discrete obstacle information and roadway boundary information,so as to ensure that the planned curve can avoid obstacles and meet the two important features of continuous curvature conductibility and early vehicle steering.Finally,the vehicle obstacle avoidance planning and tracking controller is established to solve the problems of autonomous obstacle avoidance and automatic vehicle fault when the mine vehicle is driving underground.The joint simulation platform was built to verify the performance of the controller's autonomous obstacle avoidance.The results show that in real time obstacle avoidance,no matter in the case of a single obstacle or a series of obstacles,the vehicle can avoid the obstacle and get a smooth steering input and a smooth driving path.