The Development Of The Position Measurment System Of Soil-bin Testing Platform

Soil-bin testing platform is an important equipment used for performance testing ofagricultural machinery farming components or walking device, including a soil bin and atesting platform working on it. In this paper, the position measurement system which isinstalled on the digital agricultural equipment to measure the absolute displacement is mainlydeveloped. This system can provide accurate displacement coordinates for precise testing ofagricultural machinery in the lab, realizing digitization of space-time of testing data tested byagricultural operation equipment.In this paper used the power inverter soil bin testing vehicle as the research object designthe position measuring system. The main content includes four parts: design the travel agencyof the position measuring system; design the hard ware circuit and select electroniccomponents of the position measuring system; design the software of the position measuringsystem; system simulation and test the performance.Made the following conclusions:(1) According to the performance and the conditions of installation position of thepower inverter soil bin testing vehicle, Using two-dimensional engineering drawing software—CAD making the preliminary design of the mechanical mechanism of measuring wheel.Using Pro/ENGNEER3d drawing software to make the real figure and based on theengineering drawing to simulation assembly.(2) Made the hardware circuit design of the position measuring system completed, choosethe incremental photoelectric encoder as the sensor, choose the distinguishing directioncircuit, single-chip microcomputer, digital tube, etc made of the counting circuit as thedesigning scheme. Choose74hc123and74hc00make a circuit used to determine thedirection, choose Protues software design the circuit diagram, system simulation and drawingthe printed circuit board, finally, carry on the processing.(3) Made the installation and debug of the hardware circuit completed. Take a preliminaryexperiment on the system and test the stability of its performance, the results about the testshows that the system is reliable.(4) Made the design of the software of the position measuring system, using Keil uVision2software programming and debugging. Using STC_ISP_V488software writing program. (5) Made the calibration test completed, the resolution of the system not less than0.3mm,the relative of the system is0.063‰by the proof test.This system has advantages of wide measure range and high precision, and can meet thedemand of position coordinate measurement when the digital agricultural equipment testingdevice was in orbit.