@proceedings {072310640904, title = {Experimental system identification of force reflecting hand controller}, year = {2006}, note = {

Manipulator design;Environmental impedance;Sinusoidal sweep torque input;

}, pages = {9 -}, address = {Chicago, IL, United States}, abstract = {

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 {\textcopyright} 2006 by ASME.

}, keywords = {Degrees of freedom (mechanics), Force measurement, Frequency domain analysis, Identification (control systems), Remote control, Robotics}, author = {Zumbado, Fernando and McJunkin, Samuel and O{\textquoteright}Malley, M.K.} } @article {02427145860, title = {The effect of force saturation on the haptic perception of detail}, journal = {IEEE/ASME Transactions on Mechatronics}, volume = {7}, number = {3}, year = {2002}, note = {Force saturation effect;Haptic perception;Force feedback;}, pages = {280 - 288}, abstract = {

This paper presents a quantitative study of the effects of maximum capable force magnitude of a haptic interface on the haptic perception of detail. Specifically, the haptic perception of detail is characterized by identification, detection, and discrimination of round and square cross-section ridges, in addition to corner detection tests. Test results indicate that performance, measured as a percent correct score in the perception experiments, improves in a nonlinear fashion as the maximum allowable level of force in the simulation increases. Further, all test subjects appeared to reach a limit in their perception capabilities at maximum-force output levels of 3-4 N, while the hardware was capable of 10 N of maximum continuous force output. These results indicate that haptic interface hardware may be able to convey sufficient perceptual information to the user with relatively low levels of force feedback. The data is compiled to aid those who wish to design a stylus-type haptic interface to meet certain requirements for the display of physical detail within a haptic simulation.

}, keywords = {Computer control systems, Computer simulation, Feedback control, Haptic interfaces, Identification (control systems), Nonlinear control systems, Virtual reality}, url = {http://dx.doi.org/10.1109/TMECH.2002.802725}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/omalley2002ieee.pdf}, author = {O{\textquoteright}Malley, M.K. and Michael Goldfarb} }