Time-Delay Control Using a Novel Nonlinear Adaptive Law for Accurate Trajectory Tracking of Cable-Driven Robots

In this article, we propose a novel adaptive time-delay control (ATDC) for accurate trajectory tracking of cable-driven robots. The designed ATDC utilizes time-delay estimation (TDE) to estimate the lumped dynamics of the system and provides an attractive model-free structure. Then, a robust control is designed for ATDC with fractional-order nonsingular terminal sliding mode (FONTSM) dynamics. Afterward, a novel nonlinear adaptive law is proposed for the control gains to improve the control performance. Thanks to TDE and FONTSM dynamics, the proposed ATDC is model free and highly accurate. Benefiting from the proposed nonlinear adaptive law, suppression of chattering issue and enhanced control performance have been obtained simultaneously. Stability is analyzed based on the Lyapunov approach. Then, practical experiments have been performed to illustrate the advantages of the proposed ATDC.