Design And Test Of Tractor Unmanned Driving System Based On Electro-hydraulic Integrated Control

Nowadays,the development trend of agricultural machinery is intellectualization and informationization.Unmanned driving technology of tractor is a hot research topic at present,which is of great significance to the realization of precision agriculture.The core goal of precision agriculture technology is to integrate traditional agricultural information,geographic information system,global positioning system,sensor technology and decision support system,to realize the sustainable development strategy of agriculture.Automatic navigation technology is the basis of precision agriculture and the only way to realize modem agriculture.In this paper,aiming at the requirement of tractor automatic navigation,the navigation control method is studied based on the Huanghai Jinma 554 tractor.The software and hardware platform of tractor automatic navigation is built,and the tractor automatic navigation is realized.The main research contents are as follows:(1)Hardware design of tractor automatic navigation.Beidou receiver adopts C201-AT-680 series receiver produced by Beidou Xingtong Navigation Technology Co.,Ltd.The steering column position of steering wheel is modified by adding servo motor,the clutch and brake are automatically controlled by adding push rod motor,and the accelerator is automatically controlled by adding electric oil.The method of door governor has completed the hardware modification of the system.(2)The control system of tractor is studied,including steering and braking control.The software of upper computer and lower computer is compiled.The software of upper computer is based on Windows 7 operating system.In the software of SPIDER,it is developed in Python language.The lower computer is compiled in Keil software in C language.The upper computer processes and calculates the current traveling information of the tractor and the deviation of the predetermined path,and decides the steering angle.The lower computer mainly receives instructions from the upper computer to control different motors,so as to control the lateral and vertical traveling of the tractor.(3)Navigation control algorithm is studied.Tractor kinematics is modeled.Optimal control method,pure tracking model,fuzzy control algorithm and neural network control algorithm are compared.Combining the fuzzy algorithm and pure tracking algorithm,the method based on pure tracking algorithm and fuzzy control is chosen to realize path tracking through adaptive adjustment of forward-looking distance.The simulation model is built in Matlab/Simulink,and the tracking simulation of the predetermined path is carried out under different initial conditions of lateral deviation and heading deviation.(4)The test analysis is mainly to verify the feasibility of the tractor automatic navigation system designed in the front,and to provide a certain data basis for further in-depth research.