Position and Workspace Analyses of 3-SPR and 3-RPS Parallel Manipulators

An analytic approach and a simulation mechanism for solving position and the workspace of a 3-SPR parallel manipulator are proposed. First, a simulation mechanism of the 3-SPR parallel manipulator and a simulation mechanism of the 3-RPS parallel manipulator are created by using the computer aided geometry constraints and dimension-driving techniques. Second, some analytic formulas are derived for inverse and forward solving position and orientation of the 3-SPR parallel manipulator. Third, some available solutions from multi-solutions during deriving analytic formula are determined, and analytic inverse and forward solutions are verified by using simulation mechanisms. Finally, the workspace of the 3-SPR parallel manipulator is created and three key parameters for determining work space of two kinds of parallel manipulators are solved. Calculation results prove that the position working space of the 3-SPR parallel manipulator is much larger than that of the 3-RPS parallel manipulator, and the orientation workspace of the 3-SPR parallel manipulator is less than that of 3-RPS parallel manipulator.