Research On Electronic Control Hydraulic Drive System Of Variable Fertilization In Corn

The excessive and unreasonable use of chemical fertilizers in the process of corn tillage and fertilizer application not only causes fertilizer waste,reduces fertilizer utilization efficiency,but also causes serious environmental pollution.In order to significantly improve the utilization rate of fertilizers and achieve the goal of scientific and rational application of chemical fertilizers,higher requirements are put forward for variable-rate fertilization of maize.However,at present,the domestic variable fertilization mainly adopts the soil testing variable fertilization technology,which has the shortcomings of high technical requirements and cumbersome processes,and there is less research on variable topdressing technology of corn with matching high horsepower tractor.Therefore,this paper proposes a real-time variable fertilization method which is different from the prescription map variable fertilization in order to solve the problems of low fertilizer utilization,poor real-time performance and insufficient driving force of motor driving in maize.In this study,the electric control hydraulic drive system for real-time variable fertilization in large ridge and double row maize with high horsepower tractor was constructed and verified by field experiment.In this paper,the control method of hydraulic motor speed adopts incremental PID control algorithm,and the MATLAB / simulink toolbox is used to simulate and analyze PID control.Building an electronically controlled hydraulic bench test platform,and testing the motor speed control accuracy under no-load conditions,and conducting a preliminary bench test.The PID control parameter range is determined according to the change of the speed curve.After several setting tests,the final PID control parameters are determined to be 0.73,0.47,0.40.A field experiment was carried out to verify the field experiment of 9.4 hm2 on the variable-variable fertilization system of electrically controlled hydraulic drive in corn tillage at Zhaoguang Farm,Bei’an City,Heilongjiang Province.The field test data shows that the minimum control accuracy of the first hydraulic motor speed is 97.71%,and the highest control accuracy is99.99%,so the total control accuracy of the first hydraulic motor speed is 99.13%,the root mean square error RMSE is at least 8.9 and at most 14.5.The second hydraulic motor speed control accuracy is at least 97.87%,the highest control accuracy is 99.99%,so the total control accuracy of the hydraulic motor speed is 99.30%,the root mean square error RMSE is at least 8.9 and atmost 15.6.This paper studies and analyzes the response time of the corn-farming electric control hydraulic drive variable fertilization system.The main reasons that affect the lag of fertilization are the installation position of the spectral sensor,the data collected by the upper computer,the response time of the controller,the response time of the hydraulic motor and the falling time of the fertilizer,etc.In this paper,the response time of the hydraulic motor is calculated by analyzing the speed change rate of the hydraulic motor.The lag time is calculated according to the lag distance and the driving speed of the tractor.The results show that the lag time of variable fertilization in the electronically controlled hydraulic drive system is 0.05 s.