DYNAMIC MODELING ANALYSIS OF A 4-RRR REDUNDANT PARALLEL MANIPULATOR

In this paper, a 4-RRR parallel manipulator with a square platform end effector was designed, which effectively avoiding the second kind of singularity. Firstly, A kinetic equation of a single loop was established by virtue of Lagrange equation. The complete closed chain constraint equation can be derived by establishing four branch chains and end operating stations. Subsequently, the kinematic and dynamic performance under redundant actuation and non-redundant actuation was compared and analysed It is found that the peak torque required by redundant actuation is about one sixth of that by non-redundant actuation. Moreover the active torque of each branch chain is distributed more evenly, which achieving better dynamic performance. The addition of an end effector not only enhances the mechanism's degree of freedom to execute more intricate movements, but also elevates its stability.