Constraint-Embedded Velocity Analysis of Lower-DoF Parallel Manipulators to Remove Parasitic Motion .

This work presents a methodology to analyze the constraint and motion of the lower mobility parallel manipulators at the velocity level. The work also introduced a new method to detect the parasitic (dependent) motion at the moving platform. The approach follows the analytic method of obtaining the reciprocal screws for the motion and constrain of the manipulator. Moreover, a new 3 by 3 Jacobian matrix is achieved, parasitic motion is optimized, and a non -parasitic motion improved performance manipulator is introduced. The configuration that removes the parasitic motion from the manipulator workspace has poor performance. In order to enhance the performance of optimal configuration without altering its kinematic characteristics, the spherical joint in one of the limbs is decoupled. So, the performance is improved without allowing the parasitic motion to appear in its workspace. The file can be used independently or with the papers listed in the link below. 1) https://www.sciencedirect.com/science/article/pii/S0094114X21001671 2) https://www.mdpi.com/2076-3417/11/10/4690