Nonlinear Image Based Visual Servoing Using Parallel Robots

This paper considers the control problem of an eye-in-hand type of parallel robot based precision pointing system (PRBPPS) in which the visual sensor is mounted on the platform of the parallel robot. The aim of the control is to move the platform of the parallel robot such that the image feature points reach the desired locations. An adaptive supervisory fuzzy logic controller (ASFLC) is first designed to compensate for the uncertainties of the parallel robot and uncertainty of the image Jacobian, then a hybrid controller (HC) including the image-based nonlinear controller (IBNC) and the ASFLC is derived by using the Lyapunov direct method to realize the precision position regulation (PPR). The stability of the closed-loop system in the Lyapunov sense is proven theoretically. The simulation results demonstrate that the PRBPPS realizes PPR with very good robustness to parameter uncertainties.