Application Research Of Virtual Instruments And Image Processing Technique On Seedmeter's Performance Test

The performance test of precision seeder is an important component of farm machine quality test; while the performance test of the seedmeter is especially important in developing and designing a new type precision seeder. Our research follows the work of "Research of a New Type Multi-purpose Seeder Test-bed", one of the fundamental construction items originated by Shandong Wheat Engineering Center's Agriculture and Farm Mechanization Lab. Based on a former achievement, this research applied some new research methods, like using the advanced VI(virtual instruments)technique and Image Processing technique, a program project of precision seeder performance test system was finally developed.This research work includes five parts: The first part is the Pulse Signal Detecting System, which is a velocity test system based on digital signal processing technique. This system can detect the pulses, which are generated from the sensor on the wheel and can also calculate and show the data like distance, velocity and pluses on the interface. The detecting and progressing have higher precision and the error is less than 1%. This part can also save the result data, which can be listed or printed.The second part of our research is the Image-acquiring System. The needed hardware for an Image-acquiring System and series of acquisition types are introduced in this part. This system realizes starting and controlling the hardware by the program. By combining with Signal Detecting System, this part can automatically acquire images by kinds of acquisition types.The third part is the Image Precision Processing System. This part introduces the main concept and methods of digital image processing. IMAQVision is used in this part, which provides lots of processing methods and makes the design easier. This system adopts some advanced processing methods; so it can process different types of images and makes the processing have accurate results. The processing results can also be saved to be used. The values that are needed in the program can be inputted in conveniently, which makes this part suitable for variable images.The fourth part is Dynamic Image-processing System. This part mainly processes staved images and real time acquired images. It has the same processing methods as Precision Image Processing System. By combining with Signal Detecting System, this system can acquire and process the images of sowed wheat seeds, after which, the system can get the seeds' really-space distances and then calculates the seeder's Qualification Index A, Overlapping Seeding Index D, Missing Seeding Index M and Variation Coefficient C on-line. This system can also acquire and process the images of dropping seeds, which can store the processing results. Microsoft Excel can analyze the result data and show the seed-dropping contrail.The fifth part is Image-Displaying System. The main purpose of setting up this system is to display acquired images one by one for selecting clear images. Some image processing methods, like image threshold, noise filtrates, grayscale reverse, are also used in this system for image selecting.In conclusion, the application of VI technique and Image processing technique on the precision seeder test-bed has enhanced the automatic and the intelligence of farm machine detecting level, at the same time improved the test efficiency and precision, also shortened the exploitation period.