| “Made in China 2025” plan puts the research and breakthough of intelligent agricultural machinery in the list of ten key relams.As the hottest research field of intelligent agricultural machinery,auto-guidence technology has aroused the interest of many universities and scientific research institutions and enterprises in China.Based on the project of making science and technology bring along agriculture in Shanghai,this paper focuses on the study and analysis of agricultural automatic guidance technology and seeks to design and implement an agricultural navigation management system.With the help of a high-precision paddy field path tracking controller and a precision seeding controller the system can control the rice hill-drop drilling machinery to perform a precise and automatic seeding operation.This is of greate practical significance for Shanghai to set up a state-level modern agricultural demonstration area and optimize modern agricultural machinery equipment market.The main research work of this paper is as follows:Firstly,the hardware modules of the agricultural navigation system are studied.The trator and implement runing parameters are extracted from the input and output information of these modules,which are to be monitored by the agricultural machinery navigation management system.Secondly the vehicle kinematics model and the pure persuit model of the agricultural machinery navigation are derived.And the GPS location data correction method is discussed.Then the automatic guidance system parameters are summarized.Thirdly the system is divided into seven submodules according to the requirement analysis and each submodule’s detailed scheme is carried out.The navigation system database is designed,and an adaptive path planning algorithm for paddy field seeding is presented.A reliable and reliable communication message exchange mechanism between Android terminal and vehicle controller is designed.A reliable and stable communication message exchange mechanism between Android terminal and vehicle controller is designed.Then the Android-based navigation management system application was programmed and tested.By the use of a single case model and a counter the database concurrent access exception was handled.And by using a static inner class and weak references the memory leakage problem of multithread message handler was solved.The message package sticking phenomenon disppeared after uitilizing the new message unwrapping algorithm.Finally,the field application testing of the navigation system was carried out at many times and each submodule fo the system functioned well.The software performed smoothly and presented a concise and friendly interface.The communication between the android terminal and the vehicle controller was stable and reliable,and the response of their interactive operation was timely.The navigation and monitoring interface dynamically drawed the tractor’s walking trajectory and displayed the running state parameters of the tractor in real time.Under the control of the vehicle controller the tactor tracked the planned path in a minute lateral deviance.The experiment result showed that the navigation system is of great pratical value. |
