Communication delay and jitter influence on bilateral teleoperation

Abstract

One of the most challenging problems during the design of bilateral teleoperation systems implemented over Wide Area Networks is to assure the stability and transparency in the presence of time varying communication delay between the master and the slave. In this work the influence of the delay and jitter on the passivity controller -passivity observer type stabilizers is analyzed. This control design approach does not require the explicit knowledge on the communication delay. In spite of this fact in this work it is shown that time varying the delay influences the teleoperation performances. Firstly, the relation between the delay and the dissipated energy by the controller was studied. Secondly, it was shown that in the presence of jitter the passivity controller can induce undesired oscillations into the received signals, affecting the transparency of the teleoperation. To handle this problem an extended passivity controller was proposed which assures better performances in the presence of jitter. Experimental measurements, including teleoperation experiments between two universities situated in different countries, are performed to validate the theoretical results.

Synchronization between master and slave sites in telerobotic systems: An Internet OWTD jitter prediction approach

“…Periodically, a human operator generates and sends the commands in a packet via a network to the slave system. The slave system then processes the received commands to perform local closed-loop control and returns the system output to the master site by putting sensor measurements into a frame or a packet [18].…”

Internet-based Bilateral Teleoperation Using a Revised Time-Domain Passivity Controller

“…In the case of the time domain passivity control the controller term that assures stability is activated only when an observer indicates that the passivity of the system is compromised [19]. The time domain passivity approach does not necessitate information about the communication lag, but it can be seen that the greater the delay the more energy is dissipated by the passivity controller both on the master and the slave side, as it was discussed in [14]. The paper [2] extends the concept of r-passivity to time domain passivity control schemes to assure precise position tracking and meanwhile to preserve the stability of the teleoperation in the presence of time-varying communication lag.…”

“…the experimental measurements presented in [18] or [19].) The switching is accentuated, when the communication delay is time-varying [14], as in the case of Internet-based teleoperation. To deal with these shortcomings, this paper proposes a modified time domain passivity control which assures enhanced force reflection in the presence of non-constant communication lag with bounded control actions.…”

“…To deal with these shortcomings, this paper proposes a modified time domain passivity control which assures enhanced force reflection in the presence of non-constant communication lag with bounded control actions. Our first attempt to formulate a time domain passivity controller with bounded control signals can be found in the conference paper [14]. Another approach to solve the unbounded control signal problem was proposed in the paper [25].…”

Data transfer regulator for wireless teleoperation

“…The higher is the communication delay, the harder is to guarantee stable and transparent teleoperation. The effect of delay and delay variation on the performances of bilateral teleoperation systems was analyzed in Marton et al (2014). An improved force reflecting teleoperation scheme for transparent teleoperation in the presence of delay was proposed in Jafari et al (2013).…”