Improving Tracking Performance of Nonlinear Uncertain Bilateral Teleoperation Systems With Time-Varying Delays and Disturbances

• Published in: IEEE/ASME transactions on mechatronics Vol. 25; no. 3; pp. 1171 - 1181
• Main Authors: Shen, Henghua, Pan, Ya-Jun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive control; Computer simulation; Control methods; Controllers; Delays; Disturbances; Friction; IEEE transactions; Mathematical models; Mechatronics; mixed-type feedback; nonlinear bilateral teleoperation; Nonlinear systems; nonsingular terminal sliding mode (NTSM); Numerical methods; phase shift; Robust control; Signal generators; Stability analysis; Teleoperators; time-varying network delays; Time-varying systems; Tracking; Tracking control
• ISSN: 1083-4435; 1941-014X
• DOI: 10.1109/TMECH.2019.2962663

In this article, an adaptive nonsingular terminal sliding-mode (ANTSM) method is proposed for the motion tracking control of a bilateral teleoperation system. Efforts in this article seek to improve the position tracking performance of nonlinear systems subject to time-varying network delays, parametric uncertainties, and unknown external disturbances and frictions. Another issue addressed in this article is the common delay-induced phase shift of tracking profiles in many control methods, which is greatly reduced by introducing a novel mixed type of feedback signals in the ANTSM control design. Furthermore, the proposed adaptive control design with two online-estimated compensatory bounds removes the requirement of exact knowledge of network delays and disturbance bounds as a prior. In the master side, a force predictor is used to estimate the current environmental force for the reference signal generator. Therefore, the direct transmission of force signals is avoided. By comparing with the existing model-based and model-free methods, numerical simulation results with six-degree-of-freedom manipulators illustrate the merits of the developed robust and adaptive controllers. Experimental results with two Phantom Omni devices are also provided to demonstrate the effectiveness and the significant performance improvements of the proposed controllers.