(Georgia Institute of Technology, 2003-06)
Munir, Saghir; Book, Wayne J.
This article focuses on Internet-based real time control, such as remote bilateral teleoperation. In such applications it is required that the control loop be closed around a time delayed network. Although various researchers have worked on this problem, this paper focuses on two control strategies (based on wave variables and a time forward observer), bandwidth issues, and some related programming details. Experimental results of bilateral teleoperation via the Ethernet between Atlanta and Tokyo are given. The system used was a two degree of freedom haptic interface, bilaterally coupled to simulation (implemented on a windows NT based computer) of a similar system.
(Georgia Institute of Technology, 2001-06)
Munir, Saghir; Book, Wayne J.
Wave variables based on passivity and scattering theory provide a good tool for establishing bilateral teleoperation in the presence of a constant time delay. Recently, these techniques have been extended to be used for a varying time delay, as in the case of Internet-based teleoperation. Although stability is guaranteed for virtually any time delay, performance rapidly degrades for larger delays. In this paper, a predictor derived from a modified Smith predictor along with a Kalman estimator and an energy regulator is used to enhance the performance of a wave-based teleoperator in the presence of a constant delay. Also, the current wave transformation equations are extended to a more general case (better suited for systems with multiple degrees of freedom)