Research On Navigation Control System Of Agricultural Machinery Based On UWB Positioning

With the development of modern agriculture,intelligent agricultural machinery is widely used in facility agriculture.The automatic navigation control of agricultural machinery can effectively improve work efficiency and work accuracy.Position measurement and navigation path tracking control are two important parts of automatic navigation.In this paper,aiming at the automatic navigation control of agricultural machinery in the complex working environment of greenhouse,the ultra wideband positioning system was selected as the agricultural machinery positioning system,and the path tracking control method was studied.The main works were as followsFirstly,the principle and error of UWB positioning were analyzed.This paper studied and compares several common positioning methods of UWB positioning,and selected the time difference of arrival(TDOA)as the positioning method of this paper.In view of the decrease of the accuracy of TDOA affected by the error,this paper proposed to use bivariate cubic polynomials to fit the error,and to correct the measurement point error,which was verified in the actual positioning testSecondly,the paper compared and analyzed several steering driving modes of agricultural machinery,through the research of front wheel steering and rear wheel drive of the production platform studied in this paper,so as to achieve effective control in the process of automatic navigation control The fuzzy controller of path tracking was designed,which took the lateral deviation and heading deviation as the input of the control system,and the front wheel angle as the output.The weight of the input was adjusted dynamically by combining the self-adjusting function analytical formula.The reliability of the fuzzy controller was verified by simulationFinally,the experiment of straight-line path tracking was carried out in the laboratory,and the experiment of automatic navigation was carried out in the greenhouse environment.The experimental data showed that the agricultural machinery based on ultra wideband positioning had high positioning accuracy,and the navigation control method designed in this paper could realize the control of automatic navigation in the greenhouse environment.In this paper,ultra wideband positioning was used to provide the position information for agricultural machinery,and the positioning error was corrected.At the same time,fuzzy control was used as the navigation control method to carry out automatic navigation in the greenhouse.The results showed that the automatic navigation could be completed in the greenhouse,the maximum deviation was 0.61 m,the average deviation was 0.18 m,and the accuracy was high,which could provide some reference for the follow-up research.