Development On Control System Of Variable Rate Fertilizer Applicator Based On Optical Sensor

The core of precision agriculture is variable rate management. Thus detecting and monitoring crop growth conditions with non-destructive technology are very important. There are many achievements in research on control system of variable rate fertilizer applicator at home and abroad. In spite of good performance foreign system cost highly and influenced by environmental so as to spread in our country inapplicably.While systems developed by domestic researchers have several shortcomings such as complex mechanical structure and high cost.Based on the above background, this paper developed a fertilizer application system with automatic vaiables which integrated optical sensing and data controller. This system realize the real time variable rate fertilizer by the crop growth. According to the real-time value of NDVI (normalized difference vegetation index) from NDVI equipment and the different fertilization program, the real time variable rate fertilizer was realized. the control system design and specific fertilization program has been introduced in detail.The main achivements of this study are as follows:1) Analyzed the status quo of China's agriculture and the situation of agricultural fertilizer use, discussed the importance of variable rate fertilization and the significance of development of system variables the Fertilization;2) According to the researcher of original algorithm of nitrogen fertilization and the characteristics of winter wheat in China, we suggested an optimal algorithm. Then the fertilizer nitrogen rates (FNR) used in different experimental zones were calculated by nitrogen fertilization optimization algorithm;3) Designed to adopt C8051F020 processor as the core of the control system as an executing agency of variable rate fertilizer applicator controller;4) A NDVI tester was developed to predict the nitrogen content of leaves. Design and prepare for the system hard and software. And after the design of the tester, we conducted several celibration tests, which were standard test, angle test, distance test. Introduced respectively serial communication of the CAN bus and RS-232 interface.This system characterizes by easily extended and operated, friendly human-computer interface.Problems appearing and solved in study, data acquired in experiments, and the like will be based on in further researches latterly.