Research On Controller With Id Card Function Of Variable Liquid Fertilizer

Variable rate fertilization technology plays an indispensable role in achieving sustainable agricultural development process.Since its appears to the present,it has been widely recognized.After a hundred years of research and development,the variable rate fertilization technology has matured,and has practical value.In some developed countries,the variable rate fertilization research earlier and have achieved remarkable economic benefits and environment benefits by actual agricultural production.In our country,the variable rate fertilization of research later,has yet to gain popularity.However,because of the irrational use of fertilizers leads to the destruction of farmland ecological environment.Therefore,the use of rational and science fertilization methods to solve the problem fundamentally,and controller has a variable rate fertilization function has important significance.Variable rate fertilization controller includes applicable to solid and liquid.Base on analyzing variable rate fertilization technology works and technical requirements to develop design solutions.Controller selects MCU as processor,proportional solenoid valve as executing agency.First,the article on the hardware design of the controller for analysis.The controller consists of the control board,communication module and the drive circuit.While the ID card function is applied to the controller to improve the efficiency of communication between controllers and the host computer and reduce the memory data.Second,the controller’s software has been carefully designed.it is the controller essence.Software design,including the main program,communication program and control algorithms.Use of processor timer interrupt function control valve opening and closing times. The preparation of the corresponding interface function and the development of a fixed communication data format to meet the communication controller and the host computer.Meanwhile,using PC to develop a simulation host computer system which can read the GPS information and velocity information. Through data analysis and processing, to convey instructions to the controller. For proportional solenoid valve control algorithms were studied. There have been slow to respond to the dynamic overshoot phenomenon when using PID and integral separation PID and due to the effects of stress factors, fertilization significant instability. Through in-depth analysis of the problem, is designed with hysteresis characteristics of integral separation PID algorithm. This algorithm is applied to stabilize the output, shortening the time to adjust and improve the control accuracy.After a comprehensive study,designed to a variable rate fertilization controller apply three kinds of liquid fertilizer mixing control which has ID card function and has nanual/automatic control.To test the program rationality and controller performance,static experiment and field experiment are done and the result indicates that the control system reasonable and stable.It has high control accuracy, has strong anti-jamming capability and easy to control.The controller of variable rate fertilization meets the design requirement.