@proceedings {1705, title = {Adaptive control of a serial-in-parallel robotic rehabilitation device}, year = {2013}, month = {June}, keywords = {absolute error performance, Adaptation models, adaptive control, closed form dynamic model, control system synthesis, Equations, Feedback, feedback gain, forearm rehabilitation, generalized coordinates, Manipulators, Mathematical model, medical robotics, model-based adaptive controller implementation, movement-based wrist, neurological injuries, Patient rehabilitation, RiceWrist, Robot kinematics, sensorimotor training, serial-in-parallel robot rehabilitation mechanism, serial-in-parallel robotic rehabilitation device, Trajectory, trajectory control, trajectory tracking performance, upper extremity robotic rehabilitation, Vectors}, doi = {10.1109/ICORR.2013.6650412}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/Pehlivan_AAN_ICORR2013.pdf}, author = {Pehlivan, A.U. and Sergi, F. 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.} } @proceedings {8529772, title = {Human-machine admittance and transparency adaptation in passive user interaction with a haptic interface}, year = {2005}, note = {

human-machine admittance;transparency adaptation;passive user interaction;haptic interface;force amplitude;passive user induced interactions;event-based haptic interactions;virtual environments;force amplitudes;transparency bandwidth;

}, month = {03/2005}, pages = {283 - 9}, address = {Pisa, Italy}, abstract = {

This paper addresses human adaptation to changes in coupling impedance and force amplitude during passive user induced (PUI) interactions with a haptic interface. PUI interactions are characterized as event-based haptic interactions or haptic recordings that are replayed to the user. In the study, virtual environments are displayed to passive users with variable coupling stiffness and force amplitudes, and transparency bandwidth and human-machine admittance are measured. Results indicate that transparency bandwidth and the human-machine admittance do not change significantly for permutations of force amplitudes and coupling impedances, nor do they vary significantly across users. The reason for this invariance is that, during a PUI interaction, users tend approach a similar displacement profile. As a result, all users will have similar apparent admittance and transparency. The findings give sufficient justification for the use of universal compensators that improve transparency bandwidth, and that can be designed based solely on a priori transparency measurements for a typical user

}, keywords = {Haptic interfaces, Human computer interaction, Manipulators, Virtual reality}, doi = {10.1109/WHC.2005.76}, url = {http://www2.computer.org/portal/web/csdl/doi/10.1109/WHC.2005.76}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/64-00\%20-\%20Human-machine\%20admittance\%20and\%20transparency\%20adaptation\%20in\%20passive\%20user\%20interaction\%20with\%20-\%20mcjunk.pdf}, author = {McJunkin, Samuel and Yanfang Li and O{\textquoteright}Malley, M.K.} } @proceedings {06169823659, title = {Transparency extension in haptic interfaces via adaptive dynamics cancellation}, volume = {74 DSC}, number = {2 PART B}, year = {2005}, note = {

Transparency extension;Robotic manipulators;Transparency transfer function (TTF);Model cancellation techniques;

}, pages = {1581 - 1587}, address = {Orlando, FL, United States}, abstract = {

Haptic interfaces are a class of robotic manipulators that display force feedback to enhance the realism of virtual environment displays. However, these manipulators often fail to effectively replicate the real world environment due to dynamic limitations of the manipulator itself. The ratio of the simulated to transmitted environment impedance is defined as the transparency transfer function (TTF), and can be used to quantify the effectiveness of a haptic device in displaying the simulated environment. The TTF is ideally equal to one for the bandwidth of human proprioception. In this work, a method is presented that increases TTF bandwidth via cancellation of dynamics with an adaptive model. This adaptive model is based on the kinematics and dynamics of a PHANToM haptic interface with assumed joint stiffness and damping added. The Lagrangian of the PHANToM is reformulated into a regressor matrix containing the state variables multiplied by a parameter vector. A least-squares approach is used to estimate the parameter vector by assuming that errors in force output are due to the manipulator dynamics. The parameter estimate is then used in the original model to provide a feed-forward cancellation of the manipulator dynamics. Software simulation using data from passive user interactions shows that the model cancellation technique improves bandwidth up to 35 Hz versus 7 Hz without compensation. Finally, this method has a distinct advantage when compared with other compensation methodsfor haptic interactions because it does not rely on linear assumptions near a particular operating point and will adapt to capture unmodeled features. Copyright {\textcopyright} 2005 by ASME.

}, keywords = {Adaptive control systems, Computer simulation, Linear systems, Manipulators, Mathematical models, Transfer functions}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/mcjunkin2005asme.pdf}, author = {McJunkin, Samuel and Speich, John E. and O{\textquoteright}Malley, M.K.} } @proceedings {05359336514, title = {Transparency of a phantom premium haptic interface for active and passive human interaction}, volume = {5}, year = {2005}, note = {

Active user induced (AUI);Phantom manipulators;Human operators;

}, pages = {3060 - 3065}, address = {Portland, OR, United States}, abstract = {

This paper compares two methods for determining the transparency bandwidth of an impedance based haptic interface with a Phantom 1.0A haptic device. Active user induced (AUI) interaction tests, where the system excitation is generated by a human user, show that transparency bandwidth is limited to approximately 2 Hz. Passive user induced (PUI) interaction tests, where the system excitation is generated by the haptic device with a passive human operator, show that bandwidth can extend up to 50 Hz. Experimental results show that the apparent bandwidth limitations for the AUI interaction tests are dependent on the human user{\textquoteright}s inability to excite higher frequencies. Consequently, this measurement approach is insufficient for determining system bandwidth of the human operator-haptic interface system. Furthermore, data seem to indicate that there is no appreciable difference in the ability of the Phantom manipulator to display environmental impedances in either AUI or PUI interactions regardless of the user. {\textcopyright} 2005 AACC.

}, keywords = {Acoustic impedance, Bandwidth, Manipulators}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/60-Full\%20Text.pdf}, author = {McJunkin, Samuel and O{\textquoteright}Malley, M.K. and Speich, John E.} } @article {04338307919, title = {The effect of virtual surface stiffness on the haptic perception of detail}, journal = {IEEE/ASME Transactions on Mechatronics}, volume = {9}, number = {2}, year = {2004}, note = {

Virtual surface stiffness;Haptic perception;Design specifications;Haptic interface hardware;

}, pages = {448 - 454}, abstract = {

This brief presents a quantitative study of the effects of virtual surface stiffness in a simulated haptic environment 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. Test results indicate that performance, measured as a percent correct score in the perception experiments, improves in a nonlinear fashion as the maximum level of virtual surface stiffness in the simulation increases. Further, test subjects appeared to reach a limit in their perception capabilities at maximum stiffness levels of 300 to 400 N/m, while the hardware was capable of 1000 N/m of maximum virtual surface stiffness. These results indicate that haptic interface hardware may be able to convey sufficient perceptual information to the user with relatively low levels of virtual surface stiffness. \© 2004 IEEE.

}, keywords = {Computer aided design, Computer hardware, Computer simulation, Degrees of freedom (mechanics), Manipulators, Object recognition, Sensory perception, Specifications, Stiffness, Surface properties, Virtual reality}, url = {http://dx.doi.org/10.1109/TMECH.2004.828625}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/44-09tmech02omalley-print.pdf}, author = {O{\textquoteright}Malley, M.K. and Michael Goldfarb} }