Study On Motion Law Of Materials In Air-and-Screen Cleaning Mechanism Based On High-speed Imaging System

Air-and-Screen Cleaning Mechanism has been used in cleaning agriculture materials for a long time and its basic theory of mechanical vibration has already established, however, there remains many troubles: For example, high lossing rate for humid materials; low cleaning efficiency unappeaseable for the needs of modern combine harvester. All these means: The theory of material motion is still unripe, so making an in-depth study is necessary.In this thesis, with proper assumption, a new theory of material motion on the vibration sieve was established based on collision and force theory, the full narration is as follows: During the total process of their motion, materials follow stationary motion law and nonlinear motion law. From the time they fall from the dithering plate to that they stop jumping on the vibration sieve, the materials will follow the nonlinear motion law. While sliding on the vibration sieve, they will follow the stationary motion law and when jumping from the vibration sieve again, they will follow the nonlinear motion law.Thenceforth an experiment was conducted to verify the theory. firstly, the characteristics of the materials related to cleaning performance were measured; the experiment plan was made, then motion processing system was designed : 1) The acquirement of 2-D materials moving track based on digital image processing technique; 2) The acquirement of 3-D materials moving track based on digital image processing technique ; 3) The processing software was developed with the combination of VB and Matlab, by utilizing excellent computing capacity of Matlab and the friendly user interface of VB.In the part of experimental verification, by using monocular stereo vision system and binocular stereo vision system, a conclusion was drawn: material's moving track follows stationary motion law and nonlinear motion law approximately.In this study, some instructive gropes were acquired: theory of material motion, design of motion processing system and experimental verification.To sum up, a favorable basis for more researches was made and a better reference for optimizing of the Air-and-Screen cleaning mechanism was provided .