The Control System Design Of Vehicular Fertilizer Spreader

Agricultural mechanization is the main content and the important symbol ofagricultural modernization. The degree of a country’s agricultural mechanization representsthe modernized agriculture in this country. At present,the improvement of food production inour country, because the improvement of crop varieties, production technology has beenimproved and the technology of scientific fertilization. Reasonable use of fertilizer and thetechnology of fertilization has a positive meaning to agricultural development of our country.The mechanisation of fertilizer application technology relates to the development of ourcountry’s food security and agricultural production and the development of the ecologicalenvironment is coordinated. A variable fertilization is guaranteed to meet the requirements offertilizer per unit area, improve the utilization rate of fertilizer, reducing fertilizer nutrientlosses and reduce the pollution to the environment. Because the foreign advanced fertilizerspreader can not adapt to our country’s basic national conditions and our fertilizer spreader isnot accurate, uneven, and it is not easy to control; There is rarely used computer technologyand the low level of control. So I want to design the control system design of vehicularfertilizer spreader. This system will according to the operation of fertilizer spreader’s speed tochange the quantity of fertilizer per unit time, make the fertilizer rate of per unit area remainsthe same, realize variable fertilization.（1）Determine the overall design scheme of system. According to the generalrequirements of project design, the control system should be able to realize variable control.By studying the plan, we will according to the speed of the fertilizer spreader, and bychanging the size of the spreader’s mouth where the fertilizer came out to adjust the numberof fertilizers.（2）Study on the parameters which affecting the number of fertilizers，and build thecontrol model of fertilizer consumption The results show that the height of the fertilizer whichin the box can not affect the number of the fertilizers which can be spread; There is thefunction between the size of the spreader’s mouth where the fertilizer came out and thenumber of fertilizers. System of fertilizer consumption is taken control of the closed loopfeedback control. （3）The hardware design of control system. According to the system, we has chosethe system components, testing parts and other hardware devices; we choose the single-chipmicrocomputer named STM32F103R8T6as the controller to this system, we use the chipsnamed OH44E and L9110to design the acquisition circuit of the speed, and the driver circuitof the motor drive. Integration of various modules to complete the PCB. Design a set of testdevice，which is used to the conrol system of vehicular fertilizer spreader.（4）The software design of control system. There are the Motion motor driverprogram of the fertilizer spreader, the fertilization motor driver program of the fertilizerspreader, the driver program of the Speed detection module, the driver program of the Patrolinspection module, the driver program of the detection alarm module and so on. Using thePID control algorithm in fertilizer spilling adjustment module,and the fertilizer consumptionof PID control system response time is1s.（5）Debugging and test of the system. The results show that the human-computerinteraction interface can display the system parameters properly. We can use the keyboard toset the system parameters.The system of speed measurement and infrared tube patrol workswell, and velocity measurement error is within1.77%, If the fertilizer spreader has speedchange, the Stepper motors would adjust the angle automatically to control the number offertilizers, and the number can be control, the maximum error is less than11.50%. The systemcan be used for the control of the fertilizer spreader.