On the Dynamics and Computed Torque Control of an Asymmetric Four-Limb Parallel Schonflies Motion Generator

Abstract

This paper deals with the dynamic analysis and control of a four-limb parallel Schoenflies-motion generator dedicating to fast pick-and-place operations, with an asymmetric topological architecture for saving mounting space. The concise equation of motion is built with principle of virtual work to characterize robot dynamics. Computed torque control is adopted to design the control scheme, of which the control variables are optimized by minimizing the errors of joint variables. Simulation tests are carried out along a trajectory of pick-and-place testing cycle to evaluate the control design and dynamic performances, which is verified experientially by observing the joint dynamics. The results show the effectiveness of the developed dynamic model and controller for the parallel robot under study.