@article {1718, title = {Position Synchronization in Bilateral Teleoperation Under Time-Varying Communication Delays}, year = {2014}, keywords = {adaptive control, Communication channels, Delay effects, delay systems, delays, Force, Force measurement, Ports (Computers), robust stability, Synchronization, telerobotics, time-varying systems}, doi = {10.1109/TMECH.2014.2317946}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/TMECH_Chawda2014_press.pdf}, author = {Chawda, V. and O{\textquoteright}Malley, M.K.} } @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.} } @proceedings {072310640927, title = {Vision based force sensing for nanorobotic manipulation}, year = {2006}, note = {

Nanomanipulation;Nanoassembly;

}, pages = {10 -}, address = {Chicago, IL, United States}, abstract = {

Over the last decade, considerable interest has been generated in building and manipulating nanoscale structures. Applications of nanomanipulation include study of nanoparticles, molecules, DNA and viruses, and bottom-up nanoassembly. We propose a Nanomanipulation System using the Zyvex S100 nanomanipulator, -which operates within a scanning electron microscope (SEM), as its primary component. The primary advantage of the S100 setup over standard scanning probe microscopy based nanomanipulators is the ability to see the object during manipulation. Relying on visual feedback alone to control the nanomanipulator is not preferable due to perceptual limitations of depth and contact within the SEM. To improve operator performance over visual feedback alone, an impedance-controlled bilateral teleoperation setup is envisioned. Lack of on-board force sensors on the S100 system is the primary hindrance in the realization of the proposed architecture. In this paper, we present a computer vision based force sensing scheme. The advantages of this sensing strategy include its low cost and lack of requirement of hardware modifications). Force sensing is implemented using an atomic force microscopy (AFM) probe attached to the S100 end-effector. Deformation of the cantilever probe is monitored using a Hough transform based algorithm. These deformations are mapped to corresponding end-effector forces following the Euler-Bernoulli beam mechanics model. The forces thus sensed can be used to provide force-feedback to the operator through a master manipulator. Copyright {\textcopyright} 2006 by ASME.

}, keywords = {Atomic force microscopy, Force measurement, Manipulators, Nanoparticles, Nanotechnology, Scanning electron microscopy}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/49-IMECE2006-15111-Gupta-small.pdf}, author = {Abhishek Gupta and Volkan Patoglu and O{\textquoteright}Malley, M.K.} }