Operational Space Control: A Theoretical and Empirical Comparison

Dexterous manipulation with a highly redundant movement system is one of the hallmarks of human motor skills. From numerous behavioral studies, there is strong evidence that humans employ compliant task space control, i.e. they focus control only on task variables while The International Journal of Robotics Research Vol. 27, No. 6, June 2008, pp. 737–757 DOI: 10.1177/0278364908091463 c SAGE Publications 2008 Los Angeles, London, New Delhi and Singapore Figures 1, 3–7 appear in color online: http://ijr.sagepub.com keeping redundant degrees-of-freedom as compliant as possible. This strategy is robust towards unknown disturbances and simultaneously safe for the operator and the environment. The theory of operational space control in robotics aims to achieve similar performance properties. However, despite various compelling theoretical lines of research, advanced operational space control is hardly found in actual robotics implementations, in particular new kinds of robots like humanoids and service robots, which would strongly profit from compliant dexterous manipulation. To analyze the pros and cons of different approaches to operational space control, this paper focuses on a theoretical and empirical evaluation of different methods that have been suggested in the literature, but also some new variants of op-