Bilateral teleoperation using unknown input observers for force estimation

Teleoperation systems that are distributed over large physical distances where time delays become non-negligible are becoming popular in areas such as remote medicine and operating in hazardous environments. This work proposes a new approach to the bilateral control problem that extends an earlier approach [1] based on a sliding mode controller. The existing approach requires full state and force measurements at both the master and slave sides. Here, we propose the use of unknown input sliding mode observers to estimate the states and forces and use the estimates in the controllers. This significantly reduces the difficulty of implementation and the cost of such a system, as one need only measure positions in the system. The velocity and force signals are then estimated. A proof of stability for this new approach is given. As well, the approach is verified through a numerical simulation study as a precursor to ongoing experimental verification.

[1]  Thomas B. Sheridan,et al.  Space teleoperation through time delay: review and prognosis , 1993, IEEE Trans. Robotics Autom..

[2]  Dale A. Lawrence.  Stability and transparency in bilateral teleoperation , 1993, IEEE Trans. Robotics Autom..

[3]  T. Floquet,et al.  A sliding mode approach of unknown input observers for linear systems , 2004, 2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601).

[4]  Y.B. Shtessel,et al.  Multi-rate digital design for sliding-mode-observer-based feedback control , 2005, Proceedings of the 2005, American Control Conference, 2005..

[5]  M. Hou,et al.  Design of observers for linear systems with unknown inputs , 1992 .

[6]  I. Haskara.  On sliding mode observers via equivalent control approach , 1998 .

[7]  Kyunghwan Kim,et al.  Sliding-mode-based impedance controller for bilateral teleoperation under varying time-delay , 2001, Proceedings 2001 ICRA. IEEE International Conference on Robotics and Automation (Cat. No.01CH37164).

[8]  M. Moallem,et al.  Enhanced Transparency in Haptics-Based Master-Slave Systems , 2007, 2007 American Control Conference.

[9]  Christopher Edwards,et al.  Advances in variable structure and sliding mode control , 2006 .

[10]  V. Utkin,et al.  Sliding mode observers. Tutorial , 1995, Proceedings of 1995 34th IEEE Conference on Decision and Control.

[11]  Jean-Jacques E. Slotine,et al.  Telemanipulation with Time Delays , 2004, Int. J. Robotics Res..

[12]  J. Barbot,et al.  Sliding mode observer for triangular input form , 1996, Proceedings of 35th IEEE Conference on Decision and Control.

[13]  Jong Hyeon Park,et al.  Sliding-mode controller for bilateral teleoperation with varying time delay , 1999, 1999 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (Cat. No.99TH8399).