Design And Experiment Of Variable Fertilization Sowing Control System

Precision agriculture is the general direction of the development of agriculture in the world today and in the future.It is a system supported by electronic information technology based on spatial variability,including precise geographical positioning,timing of working conditions,and input of resources to implement a full range of modern farm field operations management.Variable-rate fertilization sowing control technology is one of the most important aspects of precision agriculture.It is mainly the use of electronic computers to guide field fertilization and sowing operations in real time,in order to achieve variable inputs for the resources necessary for the overall growth cycle of crops.The rational distribution of sowing and reduction of chemical fertilizer input can not only achieve great economic benefits,but also have important historical significance for the sustainable development of the natural environment.In order to meet the needs of precision agriculture in combination with the current China's fertilizer sowing machine,this paper has designed two variable fertilizer sowing controllers,mainly composed of the core controller,human-machine interaction module,real-time sensing detection and drive actuators.Not only can it meet the basic requirements of field variable-rate fertilization sowing operations,but it also incorporates wireless transmission measurement and control and intelligent decision-making algorithms.Through the collection of variable factors affecting fertilization sowing operations,a reasonable and effective adjustment method can be judged.For the fertilization sowing operation,the speed of the implement,the standard of the preset displacement,the real-time spreading conditions and other factors will affect the accuracy of the operation,in order to detect these influencing factors,and make appropriate adjustment and control.This paper proposes two sets of variable-rate fertilization sowing control schemes,with 51 single-chip microcomputer as the core control system and ARM11 as the core intelligent control system.Both programs include two parts: the upper and the lower machines.The upper computer mainly performs man-machine interaction,calculation decisions,and command-issuing tasks.The lower computer mainly completes sensor acquisition and instruction execution tasks.Because there are multiple information acquisitions in the control system and the sensor distribution is relatively dispersed,in order to simplify the layout,the overall communication method of the system adopts wireless two-way transceiving and avoids a complicated wiring structure.The single-chip microcomputer controller can satisfy the simple variable-variable fertilization sowing operation control.Due to the limitation of its own function,it cannot develop too many additional functions.The ARM controller can meet the overall system intelligence,the background program adopts the multi-thread synchronous operation mode,and is equipped with an LCD touch screen for human-computer interaction,expansion of external storage devices,and the like.The implementing agency controls the speed of the stepper motor to drive the sowing variable of the row fertilizer.In order to improve the precision of the stepping motor control,this paper studies the PID closed-loop regulation based on the fuzzy control and uses the fuzzy control toolbox in the matlab math software to complete the fuzzy control.The design of the device and the derivation of the stepper motor transfer function model create a simulation model of the control system in the simulink library.By comparing the simulation results,the adaptive PID response time of the fuzzy PID is reduced by nearly one time compared to the conventional PID.The fuzzy PID is used for C language programming to achieve controller fuzzy adjustment.In order to verify the control effect of the field fertilization and sowing of the controller,it was connected with the fertilizer sowing machine to form an overall system,and a series of tests were completed according to the relationship among the sowing rate,the machine parameters and the control signals.Including each part of the sensor information test,fertilizer seed calibration and field operation test.After several sets of test results,the overall control system operation is stable,and the amount of fertilizer used is effectively controlled,and the seeding effect is even and appropriate.