Disturbance observer based closed loop force control for haptic feedback

TitleDisturbance observer based closed loop force control for haptic feedback
Publication TypeConference Proceedings
Year of Conference2007
AuthorsGupta, A, O'Malley, MK, Patoglu, V
Conference NameASME International Mechanical Engineering Congress and Exposition, Proceedings
Volume9 PART B
Pagination1343 - 1349
Conference LocationSeattle, WA, United States
KeywordsComputer simulation; Force control; Haptic interfaces; Robotics; Robustness (control systems)

Most commonly used impedance-type haptic interfaces employ open-loop force control under the assumption of pseudostatic interactions. Advanced force control in such interfaces can increase simulation fidelity through improvement of the transparency of the device, and can further improve robustness. However, closed loop force-feedback is limited both due to the bandwidth limitations of force sensing and the associated cost of force sensors required for its implementation. In this paper, we propose the use of a nonlinear disturbance observer for estimation of contact forces during haptic interactions. This approach circumvents the traditional drawbacks of force sensing while exhibiting the advantages of closed-loop force control in haptic devices. The feedback of contact force information further enables implementation of advanced robot force control techniques such as robust hybrid impedance and admittance control. Simulation and experimental results, utilizing a PHANToM Premium 1.0A haptic interface, are presented to demonstrate the efficacy of the proposed approach. Copyright © 2007 by ASME.

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