Study On The Test System Of Virtual Instrumentation For Precision Seed-metering Device

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. On the other hand, with the development of computer science, computer is entering test and measurement field, more and more 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 mutiples accurately. The main tasks are as following:1. Developed a new kind of sensor testing seeds dropping. Traditional seeding testing sensors have shortcomings in photoelectric units and its arrangement. Selecting right photoelectric units and right arranging mode developed the new sensor. The experimental research results show that the new sensor can give precise rate of multiples.2. The "Virtual Instrumentation"-based test system of precision seed-metering device is developed. In this research, a virtual test system is developed based on Delphi software platform, according to the design thought of Virtual instrumentation. The test system precisely measures seed spacing. The data was transferred to RAM of PC through DMA and presented by means of graph and digit on screen. In the same time, the data was sent to data files or text files. The experimental research results show that the system can give each measurement items accurately.3. The laboratory table for precision seed-metering device was designed. The laboratory table was designed with feasible speed ratios, drive and reduction device. Experiments show the laboratory table performances well.These results lay the foundation for research on the precision drills automatization, and provided important reference for using virtual instrumentation in agricultural machinery.