(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, 2002-06)
Munir, Saghir; Book, Wayne J.
Wave-based teleoperation has been previously attempted over the Internet, however, performance rapidly deteriorates with increasing delay. This paper focuses on the use of a modified Smith predictor, a Kalman filter and an energy regulator to improve the performance of a wave-based teleoperator. This technique is further extended for use over the Internet, where the time delay is varying and unpredictable. It is shown that the resulting system is stable even if there are large uncertainties in the model of the remote system (used in prediction). Successful experimental results using this technique for teleoperation in a master-slave arrangement over the Internet, where the control signal is streamed between Atlanta (Georgia) and Tokyo (Japan), are also given
(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)