Design And Experimental Research Of Fertilizer Tank Material Level Detection Device Based On Single Chip Microcomputer

Effective completion of fertilization operations is one of the important conditions to ensure the crops yield well and adequately.The yield of crops is greatly related to the reasonable use of chemical fertilizer,Once the condition of fertilizer-leakage and less-application happen,it will be bound to lead to crop reduction,So in the fertilization process,it is hard important to realize the on-line detection of the level of fertilizer box and the supplement of fertilizer in season.In this paper,we develop and design a rational detection device of the material level in the fertilizer box by MCU based on the research of the height of the material level in the fertilizer box,which instead of manual,real-time acquisition and analysis of the fertilizer surplus in the fertilizer box,and reduce the injection of human and material resources,and improve the informatization level of fertilizer applicator meanwhile.As follows are the main research contents of this paper:In the first place,we read some information related to the structural design of the detection device,and then combined with the characteristics of granular fertilizer in the fertilization process in China recently,we determined a kind of mechanical structure of parallel and adjacent bipolar plates;The device adopts the principle of capacitance detection method,the capacitance signal collected by the capacitance plate of the detection device is so small and weak that is at the PF level is one of the difficulties.Therefore,the device uses the capacitance / frequency conversion integrated circuit for the detection of small capacitance,which converts the external invisible capacitance analog quantity into the visible frequency digital signal,and the accuracy is very high.The hardware circuit design is completed by analyzing the hardware system needed for the level-detection device of the fertilizer tank,which mainly consists of capacitance measurement and acquisition module,C/F conversion module,display module and serial communication module,and use Altium Designer software to draw the hardware circuit schematic diagram,and then the system software programming is completed by computer language programming,which mainly includes capacitance data processing program,nixie tube display program,serial port communication program and main program,then compile it with keil uvisin4 software,and conducted joint simulation debugging of software and hardware in combination with Proteus ISIS,and the last,CAN-bus communication protocol is used to connect with upper-computer.Using the indoor-constructing test platform to verify that the self-made detection device can carry out real-time online detection and display the measured value of the fertilizer tank material level,and use the least square method to carry out linear fitting of the collected experimental data to calculate the sensitivity of the device is 0.1931pF/mm,and the linearity is ± 3.09%;We can prove that the equipment based on MCU can adapt to the complex field environment by the field experiment of JianShan-farm.And do an on-line measurement of the material level of the fertilizer box;At last,we tested the influence of temperature factors on the detection device,and increased the use of temperature sensor,compensated and corrected the field operation temperature.The equipment for detecting fertilizer bin material level based on MCU has good performance,and it can meet the requirements for material level detection in the process of general agricultural production,which lays a foundation for the development of intelligent control system of fertilizer applicator.