Abstract:The current domestic integration of a variable rate fertilization system and a fertilizer feeder fault alarming system has a low level, and there is less research on dynamic response of a motor driving fertilization system. A variable rate fertilizing control system supporting seeding and fertilizing monitoring was designed based on a motor driving method. The system mainly included a touch screen, a central controller and a data collector. The central controller was designed based on an MCU, which monitored both the vehicle speed by using a GPS module and the fertilization motor speed in real time. The touch screen was used to set or read the operation parameters by communicating with the controller. The data collector monitored the working status of the multiple seed metering or fertilizer feeder. An experimental platform was built to evaluate the monitoring accuracy. When the sowing axle speed was 12.5~125r/min and the monitoring sensitivity was set to 3s, the accuracy of the fault alarming system was 100%. A test was conducted to find the system response time with different fertilization rates, the test results showed that the maximum system response time was 0.75s when fertilization rate was from 0g/min to 11500g/min.The prototype machine test result showed that when the fertilization rate was from 75kg/hm2 to 450kg/hm2 with an increment of 75kg/hm2, the average system response time was 1.08s. When the fertilization rates were 450kg/hm2, 600kg/hm2 and 750kg/hm2 with different vehicle speeds, the average accuracies of fertilizer ejecting were 95.92%, 95.24% and 98.26%, and the variances were 3.01%, 1.39% and 1.36%, respectively. The field test results showed that when the fertilization rates were set to 450kg/hm2, 600kg/hm2 and 750kg/hm2, the average accuracies of fertilizer ejecting was 94.69% with variance of 2.23%, and the accuracy of the fault alarm for multiple feeders was 100%.
