Research And Apply On The Structure Synthesis Of Parallel Mechanism Based On POC Set

The research of type synthesis of parallel mechanism has veryimportant theoretical and practical significance,and always gains theattention of researchers at home and abroad. This paper use the theory andmethod of type synthesis of parallel mechanisms based on POC (Positionand Orientation Charateristic) to research the type synthesis, positionanalysis and application of the new type. At first, it presents the basictheory and general steps of type synthesis method based on POC; Then,based on this method,13kinds of (3T-0R) and15kinds of (3T-3R) parallelmechanism types are synthesized, and analysis and classification oftopological structure types about the new synthesis of mechanism areengaged in, which perfect the parallel mechanism type base. After that,according to the optimization principle of the main mechanism of theparallel vibration sieve, some types which meet the requirement ofvibration sieve’s sifter motion are selected from numerous existing andnewly discovered3DOF types, and8single types are obtained byoptimizing and improving. Furthermore,{-R-R-S-}+{-S-S-}+{-S-},a optimized type selected from this, is progressed for kinematicssimulation analysis and model design. Finally, according to the forwarddisplacement analysis method based on analysis of coupling degree oftopological mechanism, the forward displacement analysis problems ofthe6dof parallel mechanism:6-31-2-3SPS,2-2-2SPS and6-42-2-1-1SPS, are solved respectively, which establishs the motion consistencycondition based on the analytic solutions of1-2-3-SPS parallel mechanism,and obtains8groups,16groups,32groups numerical solutions of positivesolutions by singlevariable optimization respectively, and validates thecorrectness of the forward and inverse displacement analysis by examples.