Research On Multi-objective Optimal Control Of Agricultural Automatic Navigation Vehicle

With the gradual advancement of agricultural modernization,the automatic navigation technology of agricultural machinery has become a research hotspot.The automatic navigation technology of agricultural machinery can effectively relieve human labor and reduce labor costs,which is of great significance to solve social problems such as population aging and agricultural labor shortage.In order to make the agricultural machinery achieve the comprehensive optimization of stability,accuracy and rapidity in the process of automatic navigation,the study on the optimal control of agricultural automatic navigation vehicle is conducted in this paper.The specific research content is as follows:(1)Based on the improved pure tracking algorithm,a quantitative analysis model on the pose error of navigation vehicle was proposed.On the basis of the analysis model,a dynamic forward-looking distance controller was designed;through the optimization of the path switching scheme,it proposed a method to switch paths in advance at a suitable distance.The results showed that the average stable distance of optimized linear test was 124.75 cm less than that before optimization,and the average time before optimization was 7.4 s less than that before optimization.(2)Through the improvement of the traditional bug algorithm,and combined the obstacle avoidance algorithm with the path tracking algorithm,the obstacle avoidance process of the traditional bug algorithm can be divided into three stages: tracking,avoiding and detouring;in the avoidance phase,the index map of obstacle avoidance advance turning distance and steering angle was established to make the navigation vehicle use the maximum steering angle to avoid obstacles at the appropriate time;in the bypass phase,the fuzzy controller with self-adjusting function was in the control of the navigation vehicle to move around the edge of the obstacle.The test results showed that the navigation vehicle can avoid obstacles accurately and stably,besides,the redundancy of obstacle avoidance track was relatively short.(3)The optimal control evaluation system was constructed according to the three driving performance indexes,and the optimal control evaluation formula of navigation vehicle was obtained by the weight ratio of each performance index collected through questionnaire survey.The double deviation speed controller was designed to confirm the optimal value and minimum speed by simulation test.In the straight-line path and broken-line path tests,the overall optimality of the transmission control was optimized by 15.79% and 34.43%,respectively.In this paper,the navigation control of the vehicle was optimized at the navigation algorithm level and the integrated control level,so that the navigation vehicle can achieve the comprehensive optimization of stability,accuracy and rapidity in the operation process,and further provide certain reference to improve the efficiency of agricultural machinery navigation.