Research On Motion Law Of Partical In Cleaning Sieve Based On Image Analysis

With increasing of high-qualified grain's requirement on the market and spreading of grain growth's area, it's imperative to develop high-efficient harvesting machinery which is suitable for grain reaping, threshing separating and cleaning. And, the grain cleaning mechanism, which is a very important part of the combine harvester, directly influences the working performance of the machine. At present, almost all the improvement of grain cleaning mechanism is only cursorily changing the structure of machine, and the extended study for the airflow parameters and working parameters during the cleaning process, is limited. Therefore, it is very significant to deeply research the grain cleaning mechanism.This paper collected lots of documents about the methods used on measuring particle velocity in stream-solid flow and applied condition of high-speed photography in agriculture, and determined image analysis was used in this research.First of all, analyzing the movement as well as the movement differential equations of threshes materials in the airflow, the movement model was built, and by the software of ADAMS, the airflow parameter's influence on the state of the thresh materials was studied, and based on the simulated results, the airflow parameters were chosen scientifically. Meanwhile, after the movement rule of the thresh materials on the sieve is analyzed, the formulas which meet all the movement circumstance were built, and the movement models of the thresh materials were built.Secondly, an experiment system was built, which was composed by small test-bed and image acquisition system. The small test-bed included cleaning sieve, electric motor, blower and transducer. Image acquisition system consisted of CMOS camera, lens, transmission line and PC. And by meaning of calibrating camera, the recessive parameters was determined.Finally, using CMOS camera , a lot of pictures about particle moving condition under different parameters were taken .These parameters include vibration frequency of sieve , obliquity of sieve , velocity and angle of stream. Processing the pictures, the track diagrams and velocity diagrams were made .This experiment confirms that the method which was used to analyzed the moving law of particle was feasible. Through analyzing the track and velocity diagrams, this paper worked out the stream velocity influenced the moving conditions most, and the effect of sieve obliquity was also obvious.Above all, this paper made instructive endeavor on establishing particle moving law, designing image acquisition and doing experiment, and provide foundations for future research.