Adaptive impedance control in haptic teleoperation to improve transparency under time-delay

Abstract

This paper proposes the application of an adaptive impedance control scheme to alleviate some of the problems associated with the presence of time delays in a haptic teleoperation system. Continuous on-line estimation of the remote environment's impedance is performed, and is then used as a local model for haptic display control. Lyapunov stability of the proposed impedance adaptation law is demonstrated. A series of experiments is performed to evaluate the performance of this teleoperation control scheme. Two performance measures are defined to assess transparency and stability of the teleoperator. Simulation results show the superior performance of the proposed adaptive scheme, with respect to direct teleoperation, particularly in terms of increasing the stability margin and of significantly ameliorating transparency in the presence of large time delays. Experimental results, using a Phantom Omni as the haptic master device, support this conclusion.

Point-cloud-based model-mediated teleoperation

“…One of the main tasks of a MMT system is to estimate the environment parameters [16][17][18][19][20][21][22][23][24]. In [16], a damper-spring model is adopted to approximate the environment, and a sliding average least-square algorithm is proposed to estimate the dynamic parameters of the environment on the slave side for online updating of the virtual model parameters on the master side in the presence of large communication delay.…”

Transparent and Shaped Stiffness Reflection for Telesurgery

“…However, from such plots, it is difficult to analyse what the human operator feels. For this purpose, it is more useful to present the experimental data on force versus position plots, as done by De Gersem et al (2005a); Mahvash & Okamura (2007); Tzafestas et al (2008); Willaert et al (2008b). Both ways of plotting the experimental data in the time-domain are employed in this chapter.…”

“…Doarn et al, 2007;Lum et al, 2009;Rayman et al, 2006), although the current practice is that both the master and the slave are located in the same surgical room. As mentioned in the introduction, different controllers of the third concept have been presented in order to provide useful haptic feedback for time-delayed systems (Funda & Paul, 1991;Hashtrudi-Zaad & Salcudean, 1996;Ji et al, 2005;Kuan & Young, 2003;Mitra & Niemeyer, 2008;Tzafestas et al, 2008). Note that the estimatesk e andf o are transferred from the slave to the master through the communication channel.…”

“…As mentioned by Funda & Paul (1991); Hashtrudi-Zaad & Salcudean (1996); Ji et al (2005); Kuan & Young (2003); Mitra & Niemeyer (2008); Tzafestas et al (2008), a teleoperation system with model-based haptic feedback is more robust with respect to communication time delay. The increased robustness is even not restricted to the problem of communication time delay.…”

On autonomous and teleoperated aerial service robots

“…Although impedance reflection has been used in classical teleoperation schemes [41], [114], its application in the context of aerial robotics is new. The main goal of reflecting the impedance of the remote environment is to bypass the coupling between the master and the slave that suffers from the network-induced imperfections.…”