@article {071210493824, title = {Design of a haptic arm exoskeleton for training and rehabilitation}, journal = {IEEE/ASME Transactions on Mechatronics}, volume = {11}, number = {3}, year = {2006}, note = {

Arm exoskeletons;Apparent inertia;Design methodology;

}, pages = {280 - 289}, abstract = {

A high-quality haptic interface is typically characterized by low apparent inertia and damping, high structural stiffness, minimal backlash, and absence of mechanical singularities in the workspace. In addition to these specifications, exoskeleton haptic interface design involves consideration of space and weight limitations, workspace requirements, and the kinematic constraints placed on the device by the human arm. These constraints impose conflicting design requirements on the engineer attempting to design an arm exoskeleton. In this paper, the authors present a detailed review of the requirements and constraints that are involved in the design of a high-quality haptic arm exoskeleton. In this context, the design of a five-degree-of-freedom haptic arm exoskeleton for training and rehabilitation in virtual environments is presented. The device is capable of providing kinesthetic feedback to the joints of the lower arm and wrist of the operator, and will be used in future work for robot-assisted rehabilitation and training. Motivation for such applications is based on findings that show robot-assisted physical therapy aids in the rehabilitation process following neurological injuries. As a training tool, the device provides a means to implement flexible, repeatable, and safe training methodologies. \© 2006 IEEE.

}, keywords = {Damping, Degrees of freedom (mechanics), Joints (anatomy), Patient rehabilitation, Robot applications, Sensory perception, Stiffness}, url = {http://dx.doi.org/10.1109/TMECH.2006.875558}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/47-IEEEASME_HapticArmExoskeleton.pdf}, author = {Abhishek Gupta and O{\textquoteright}Malley, M.K.} } @proceedings {04278244649, title = {Comparison of human haptic size discrimination performance in simulated environments with varying levels of force and stiffness}, year = {2004}, note = {

Size discrimination experiments;Machine quality;Haptic devices;

}, pages = {169 - 175}, address = {Chicago, IL, United States}, abstract = {

The performance levels of human subjects in size discrimination experiments in virtual environments with varying levels of stiffness and force saturation are presented. The virtual environments are displayed with a Phantom desktop three degree-of-freedom haptic interface. Performance was measured at below maximum machine performance levels for two machine parameters: maximum endpoint force and maximum virtual surface stiffness. The tabulated scores for the size discrimination in the sub-optimal virtual environments, except for those of the lowest stiffness, 100 N/m, were found to be comparable to that in the highest-quality virtual environment. This supports previous claims that haptic interface hardware may be able to convey, for this perceptual task, sufficient perceptual information to the user with relatively low levels of machine quality in terms of these parameters, as long as certain minimum levels, 1.0 N force and 220 N/m stiffness, are met.

}, keywords = {Computer simulation, Computer software, Degrees of freedom (mechanics), Feedback, Haptic interfaces, Human engineering, Stiffness}, url = {http://dx.doi.org/10.1109/HAPTIC.2004.1287193}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/upperman2004haptics.pdf}, author = {Gina Upperman and Suzuki, Atsushi and O{\textquoteright}Malley, M.K.} } @proceedings {05239144488, title = {Design of a haptic arm exoskeleton for training and rehabilitation}, volume = {73}, number = {2 PART B}, year = {2004}, note = {

Haptic arm exoskeleton;Inertia;Structural stiffness;Kinesthetic feedback;

}, pages = {1011 - 1018}, address = {Anaheim, CA, United States}, abstract = {

A high-quality haptic interface is typically characterized by low apparent inertia and damping, high structural stiffness, minimal backlash and absence of mechanical singularities in the workspace. In addition to these specifications, exoskeleton haptic interface design involves consideration of additional parameters and constraints including space and weight limitations, workspace requirements and the kinematic constraints placed on the device by the human arm. In this context, we present the design of a five degree-of-freedom haptic arm exoskeleton for training and rehabilitation in virtual environments. The design of the device, including actuator and sensor selection, is discussed. Limitations of the device that result from the above selections are also presented. The device is capable of providing kinesthetic feedback to the joints of the lower arm and wrist of the operator, and will be used in future work for robot-assisted rehabilitation and training. Copyright {\textcopyright} 2004 by ASME.

}, keywords = {Actuators, Bandwidth, Damping, Degrees of freedom (mechanics), Friction, Human computer interaction, Kinematics, Robotic arms, Robots, Sensors, Stiffness}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/gupta2004asme.pdf}, author = {Abhishek Gupta and O{\textquoteright}Malley, M.K.} } @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} }