Fuzzy sliding mode variable structure control of a high-speed parallel PnP robot

This paper presents the analysis and experimental evaluation of robot dynamics and control for a four-limb parallel Schonflies-motion generator dedicating to fast pick-and-place operations, with a different topological architecture from its counterparts for efficient use of shop-floor space. The concise equation of motion is built with principle of virtual work to characterize the robot dynamics, which is integrated into the model-based control design. Fuzzy sliding mode variable structure control is adopted for the design of control scheme, aiming at buffeting suppression of the actuated joints and minimization of pose errors of robot end-effector. Numerical simulations are carried out along a trajectory of an industrial standard testing cycle to evaluate the performance, which is validated experientially by observing the joint dynamics. The results show the effectiveness of the developed dynamic control scheme for fast parallel pick-and-place robots. (c) 2021 Elsevier Ltd. All rights reserved