Stiffness Study Of2-RPS&PSR Parallel Mechanisms

Parallel Robot with less DOF is one of hot research fields recently, and whoseapplication also shows good prospects in different fields.When parallel mechanism is used, many problems will be appearing for the casesthat how to avoid and correct the unknown things. We can analyze the position ofinstitutions firstly, and then to analyze the workspace and rigidity of structure, so as todraw relevant conclusions. The position analysis of structure is the basis of theworkspace analysis, and workspace is one important indicator of the performances formeasuring the machine stiffness. Strengthening the study of rigidity analysis is animportant factor for the parallel mechanism when it is used in the practical application.These performance indicators are core contents for the structural design and severalapplication.In this chapter, a variant agency2-RPS&PSR of3-RPS parallel mechanism ischoose d to be the subject, which uses the analysis from the position and stiffness. Italso shows the simulation and finite element analysis.The research work is as follows: The vector algebra of analytical methods isadopted to solve the inverse problem of the positions, and the orientation of parallelmechanism is also be described, which can solve the workspace. The screwed theoryis used to solve the entire organization Jacobian matrix in the stiffness analysis, whichcan deduce the stiffness matrix organization, and then uses the analytical method toanalysis the structural stiffness. These singularities can be avoided by the localcoordinate system, which greatly simplifies the process of analyzing institutions.The paper analyzes the position and stiffness firstly, and then the simulation ofMatlab is obtained. It shows the visual picture, which can prove the feasibility of theparallel robot that achieves the expected movement. They are very helpful for thedesign, checking and debugging.The natural pattern of parallel mechanism (2-RPS&PSR) is constructed by thesoftware of Crea.2, which can help us see the operation method more intuitively.The force analysis at different positions are used by the software of ANSYS that is reflected by the variation of cloud picture. It can shows the factors that changed thestiffness, and reflects the places of weakness.