Research On The Key Technology Of High Precision Autonomous Farming For Wheeled Tractor

In order to improve the developing level of automation,information and intelligence of the agricultural machinery,minimize the error of manual operation,increase efficiency and save the farmland,the navigation control technology of automatic farming machinery that based on YSH-504 D wheeled tractor was studied.Carrier wave phase differential GPS positioning technology assisted by inertial navigation system was adopted in the research,various data were fused in Kalman filter which can deal with the navigation parameters smoothly.The GPS positioning error caused by inclined landform and nonuniform hardness of soil can be corrected,so the traveling track of the tractor would be smoother.Through analyzing different ways of path planning,a steering strategy determined by distance difference between current point and target point is designed.The steering PID controller can control the turning direction by steering mechanism which uses the angle deviation between nose wheel actual steering angle and target angle as input variable.The project stemmed from practical situation,a large amount of domestic and abroad literatures were referenced for the study,the overall scheme mainly includes embedded microcontroller module,GPS receive module,LCD module,relay control module and so on.The hardware platform was built by selecting appropriate microcontroller and sensors.The navigation control algorithm is simulated,path tracking real vehicle test and GPS track revising test were implemented at last.The testing results show that the tractor can trace the target track with calibrated GPS navigation parameters smoothly and work automatically on complicated landform.,and the navigation precision can reach centimeter level.