A sliding-mode controller for dual-user teleoperation with unknown constant time delays

Mahya Shahbazi, S. Farokh Atashzar, H. A. Talebi, F. Towhidkhah, M. J. Yazdanpanah

Research output: Contribution to journalArticlepeer-review


In this paper, a control methodology is proposed for dual-user teleoperation system in the presence of unknown constant communication time delay. To satisfy dual-user system-desired objectives, three impedance characteristics are defined as the desired closed-loop system. In order to satisfy the desired impedance characteristics, a sliding-mode-based impedance controller is applied. The proposed controller affords unknown communication delay, an issue that is disregarded in the previous studies performed on dual-user systems. The nonlinear gain of the controller is achieved independent of time delay caused by communication channels. Therefore, the necessity of measurement or estimation of the time delay is relaxed. In addition, the stability analysis is presented for the closed-loop system using the passivity theory. The validity of the proposed controller scheme is demonstrated via experimental results performed on a dual-user system in the presence of unknown communication delay. In addition, due to lack of availability of forces corresponding to the operators' hand that are required in the proposed controller, a Kalman Filter-based Force Observer (KFFO) is proposed.

Original languageEnglish (US)
Pages (from-to)589-598
Number of pages10
Issue number4
StatePublished - Jul 2013


  • Dual-user system
  • Multi-master/single- slave system
  • Sliding-mode control
  • Teleoperation
  • Unknown time delay

ASJC Scopus subject areas

  • Software
  • Control and Systems Engineering
  • General Mathematics
  • Computer Science Applications


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