This paper presents an extended adaptive control scheme via terminal sliding mode (TSM) for cable-driven parallel manipulators (CDPM). Compared with linear hyperplane-based sliding mode control, TSM is able to guarantee highprecision and robust tracking performances which arise from its main feature of finite-time convergence. This motivates applying TSM to robotic manipulators in general and, as presented in this paper, to CDPM in particular. The scheme presented in this paper extends early developed TSM control schemes which are based on partial knowledge of system dynamics. Instead, making use of the property that the dynamic models of mechanical manipulators are linear in inertial parameters, an adaptive control law is synthesised based on an appropriate choice of Lyapunov function which guarantees finite-time convergence to neighborhood of sliding mode. A key challenge of the control of CDPM is that cable tensions must be admissible, i.e. lying in a non-negative range of admissible values. As long as cable tensions are admissible, the overall dynamics of CDPM can be easily written in either actuator space or operational space which in turn facilitates control system design. The extended adaptive control scheme has been applied to a large redundantly actuated CDPR prototype, CoGiRo. Simulation results show the effectiveness of the proposed control method.
This paper presents a new adaptive controller based on terminal sliding mode (TSM) control for parallel manipulators. More precisely, the proposed controller is based on a finite-time continuous TSM control scheme. To improve the tracking performance of parallel manipulators, a novel adaptive TSM control scheme is proposed in this paper. Based on the linear-in-the-parameters property of the dynamic model of rigid mechanical manipulators, an adaptive law is proposed to adjust the dynamic parameters of the manipulator in real-time. The proposed controller has the advantages of relying on the desired trajectories instead of measured ones which improves its robustness and efficiency. To demonstrate the effectiveness of the proposed controller, real-time experiments are conducted on a four degree-of-freedom (4-DOF) parallel manipulator called Veloce.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.