Experimental system identification of force reflecting hand controller

TitleExperimental system identification of force reflecting hand controller
Publication TypeConference Proceedings
Year of Conference2006
AuthorsZumbado, F, McJunkin, S, O'Malley, MK
Conference NameAmerican Society of Mechanical Engineers, Dynamic Systems and Control Division (Publication) DSC
Pagination9 -
Conference LocationChicago, IL, United States
KeywordsDegrees of freedom (mechanics); Force measurement; Frequency domain analysis; Identification (control systems); Remote control; Robotics

This paper describes the combined time and frequency domain identification of the first three degrees-of-freedom (DOF) of a six degree-of-freedom force reflecting hand controller (FRHC). The FRHC is used to teleoperate Robonaut, a humanoid robotic assistant developed by NASA, via a bilateral teleoperation architecture. Three of the six DOF of the FRHC are independently identified due to the decoupled nature of the manipulator design. The frequency response for each axis is acquired by coupling a known environmental impedance to the joint axis and then applying a sinusoidal sweep torque input. Several data sets are averaged in the frequency domain to obtain an averaged frequency response. A coherence analysis is then performed and data with low coherence values are ignored for subsequent analysis and model fitting. The paper describes the use of coherence data to ensure acceptable model fits for transfer function estimation. Results of the identification experiments are presented, including implications of assumptions of decoupling and linearity. In addition, frequency and time domain validations for each axis model are performed using data sets excluded from the parameter estimation, with strong correlation. Copyright © 2006 by ASME.