Workspace Analysis Of A 6-DOF 3-RRRS Parallel Manipulator

The design of a spatial parallel robot is governed by two factors: volume of the workspace and shape of the workspace. In this paper, we subject a 6-DOF 3RRRS parallel manipulator having symmetric link lengths, under research. The most commonly used method to solve robot kinematics based on the Denavit-Hartenberg (D-H) notation. Since its inverse kinematics involves complicated calculations and solutions, there has been a need to develop a new method which can meet the demands of real-time applications. Derived from the basis of screw theory, a new improved inverse kinematic approach, which improves the efficiency of the inverse kinematics, is used. Along with Paden-Kahan sub-problems, a new and improved subproblem is used to counter the aforementioned problems. In order to arrive at a robust design, the required volume is taken as input while all parameters relating to a manipulator design, such as the link lengths, the moving plate and base plate radius, the orientation, the home angle configuration are all treated as variables while computing the inverse kinematics. In each case, the corresponding geometric relationship between the parameters of the manipulators is established. The configuration which satisfies the user requirements as well as with the least amount of singularities is provided as the result.