Workspace Based Controller Design and Performance Evaluation of MDOF Force Sensorless Bilateral System

Abstract

SUMMARY Redundant multi-degree-of-freedom (MDOF) bilateral system in workspace is expected to be a key technology for the development of next-generation robots because of the variety of feasible tasks. Nowadays, four-channel bilateral structures based on acceleration control have been introduced to realize both position and force tracking in a bilateral control system. Additionally, torque observers have been implemented to facilitate force feedback without the use of torque/force sensors. However, differences in controller composition between the joint space and workspace are still unclear. In particular, observer designs in both spaces are important for a realization of torque/force sensorless bilateral control. This paper presents a performance evaluation of an MDOF force sensorless bilateral system performed by considering the design space of observers by numerical and experimental analyses. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 70–80, 2014; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22481