Performance evaluation of parallel manipulators: Force transmissibility of planar parallel manipulators

This paper concerns the problem of performance evaluation of parallel manipulators. Although parallel manipulators have been extensively studied for more than twenty years, unfortunately, the concepts of manipulability and condition number were, in general, directly transposed from serial robots from the very beginning. Recently, both theoretical analysis and experiences indicate that these concepts, especially the local conditioning index (LCI), seem defective when they are applied in parallel manipulators. Compared with serial robots, parallel manipulators are better in force transmission. This paper tries to evaluate the performance of parallel manipulators from the view of force transmissibility. This concept is proposed, in this paper, from the investigation of planar parallel manipulators. It shall be said to be extended to other parallel manipulators.