Optimum transmission performance of 3-RRR planar parallel manipulators and sensitivity analysis

Abstract

In this paper, a parametric model of 3-RRR planar parallel manipulators (PPMs) is presented, aiming to optimize the overall transmission performance with optimum shapes and sizes of platforms, including the base and the mobile platform. By utilizing the duality of motion and force spaces, an analytical approach is presented through the formalities of linear algebra so as to evaluate transmission performance of planar 3-RRR manipulators, upon which an optimum design is conducted. Moreover, sensitivity analysis is accomplished to reveal the influences of the design parameters on the overall performance of manipulators. With the developed fully parameterized model, optimal configurations of 3-RRR PPMs are studied. In total, six configurations with optimal transmission quality are identified, most of them having mobile platforms of either opened, or folded shape. An optimal design case is finally included to demonstrate further its transmission performance.