Bilateral control with time-varying delay including communication blackout

Abstract

We have already proposed a bilateral control scheme with energy balance monitoring under time-varying communication delay. In this paper, experimental results using the proposed control scheme over the computer network are shown. In the previous work, we dealt with a situation when the communication is in breakdown. However, we did not discuss how to recover the system after the communication line comes back. In this paper, we also propose a way to recover the system from the communication blackout. Experimental results show the validity of the proposed methods.

Transparent Data Reduction in Networked Telepresence and Teleaction Systems. Part II: Time-Delayed Communication

“…The underlying idea is to observe the energy balance of the communication subsystem including data reconstruction online; similar ideas of energy monitoring have been applied for the case of time-varying delay (Niemeyer & Slotine, 1998, Yokokohji et al, 2000 and packet loss (Yokokohji et al, 2002). As the standard case a transparent, but potentially energy generating reconstruction strategy ζ np is applied.…”

“…In sum-mary, the major control challenges for networked haptic telepresence systems induced by the communication are: 1) time delay due to data transmission, 2) limited communication resources, and 3) loss of data. Sophisticated stabilizing control methods have been developed in the past for time delay (Anderson & Spong, 1989;Niemeyer & Slotine, 1991;Kosuge et al, 1996;Niemeyer & Slotine, 1998;Yokokohji, Imaida, & Yoshikawa, 2000;Lozano, Chopra, & Spong, 2002;Munir & Book, 2002Stramigioli, 2002) and the data loss problem (Secchi, Stramigioli, & Fantuzzi, 2003;Berestesky, Chopra & Spong, 2004;Hirche & Buss, 2004;Yokokohji, Tsujioka, & Yoshikawa, 2002). The challenge of limited communication resources is poorly treated in the known telepresence literature.…”

Sampled data systems passivity and discrete port-Hamiltonian systems

“…Scattering theory has been also used in [19], [20] to build bilateral telemanipulation systems, in [21] for dealing with the variable delay problem and in [22] to build a passive position controlled teleoperator. A very suitable tool to solve the second problem is passivity theory and the control of the energy exchange between the interacting systems using IPCs [11].…”

“…A definition of passivity based on scattering variables can be given. If is the power port by means of which a system interacts with the rest of the world and if is its scattering representation, we have that a system is passive iff such that (20) Loosely speaking, a system is passive iff the outcoming energy bounded by the incoming energy, namely iff there is no internal production of energy.…”

“…Proof: Since the nondelayed system is passive we have that condition (20) holds and therefore that (27) Let us now consider the delayed output . We have that…”