Study On Precise Seed-meter Of Loss Testing And Compensation Technique Based On Virtual Instrument

Precise and efficient test system is very important to study and design precision seed-metering device. But our current test techniques and instruments for precision seed-metering device are still in low level, which impedes the development of quality precision seed-metering device. With the development of computer science, computer is entering test and measurement functions that used to be acquired by hardware can be realized through software. Thus, the "Virtual Instrumentation (VI)" is produced.The virtual instrumentation has many merits compared with conventional instrument. It has been used in many fields. But it is still in experimental phase to use in precision drills. Based on above reasons, our study goal is to develop quality test system that can give the rate of multiples accurately. The main tasks are as following:(1) Has selected appropriate trough type electro-optical sensor E3S-GS15N, designed sensor to measure the rotate speed in the pulse cycle method. The experiment indicated this sensor can satisfy the request of the seeding performance examination.(2) To study and develop the test system of dropping performance based on Virtual Instrumentation. According to the design thought of Virtual Instrumentation .and using the way that the software is key and combining with hardware, and the developing platform is Lab view, I developed the leaking sow testing and compensation system software.(3) Carried on the mark of the system ,to check the piece of the whereabouts seed that the system examine each time whether fit or not.Experimented confirmed that the design of the examination system is dependable and accurate.(4) To analyze the grain of distance sample test result, obtained the seed-meter estimating indexes: qualified, rebroadcast ,loss .average .standard deviation and variance modulus etc . Drew up a row of exponential curve on the qualified index and leaked broadcasts under a different seeding frequency ,this curve indicated seed-meter leaked rate increase with the frequency of seed-meter increasing, and the qualified rate reduces. It matched with the rule of actual seed-meter, thus confirmed more the accuracy and the reliability on seed-meter leaking test system.(5) Designed the electric circuit to actuate the leaking and compensating electromagnetic valve and the compensation set. When a grain of tested distance was bigger than a theory grain of 1.5 times distance, regarded it as leaking broadcasts, this system will feedback the tested signal for the data acquisition card PCI-6040E counter...