@article {103, title = {Negative Efficacy of Fixed Gain Error Reducing Shared Control for Training in Virtual Environments}, journal = {ACM Transactions on Applied Perception}, volume = {6}, number = {1}, year = {2009}, month = {01/2009}, abstract = {

Virtual reality with haptic feedback provides a safe and versatile practice medium for many manual control tasks. Haptic guidance has been shown to improve performance of manual control tasks in virtual environments; however, the efficacy of haptic guidance for training in virtual environments has not been studied conclusively. This article presents experimental results that show negative efficacy of haptic guidance during training in virtual environments. The haptic guidance in this study is a fixed-gain error-reducing shared controller, with the control effort overlaid on the dynamics of the manual control task during training. Performance of the target-hitting manual control task in the absence of guidance is compared for three training protocols. One protocol contained no haptic guidance and represented virtual practice. Two protocols utilized haptic guidance, varying the duration of exposure to guidance during the training sessions. Exposure to the fixed-gain error-reducing shared controller had a detrimental effect on performance of the target-hitting task at the conclusion of a month-long training protocol, regardless of duration of exposure. While the shared controller was designed with knowledge of the task and an intuitive sense of the motions required to achieve good performance, the results indicate that the acquisition of motor skill is a complex phenomenon that is not aided with haptic guidance during training as implemented in this experiment.

}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/103-Li-Patoglu-O\%27Malley_TAP_6\%281\%29_2009FINAL.pdf}, author = {Yanfang Li and Volkan Patoglu and O{\textquoteright}Malley, M.K.} } @article {102, title = {Passive and Active Discrimination of Natural Frequency of Virtual Dynamic System}, journal = {IEEE Transactions on Haptics}, volume = {2}, number = {1}, year = {2009}, month = {02/2009}, pages = {40-51}, doi = {10.1109/TOH.2008.21}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/102-Israr-Li-Patoglu-O\%27Malley_IEEEToH_2\%281\%29_2009FINAL.pdf}, author = {Ali Israr and Yanfang Li and Volkan Patoglu and O{\textquoteright}Malley, M.K.} } @proceedings {109, title = {Progressive shared control for training in virtual environments}, year = {2009}, month = {03/2009}, pages = {332-337}, publisher = {IEEE}, address = {Salt Lake City, UT, USA}, keywords = {Haptic interface, performance, shared control, training}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/109-LiPSC-WHC.pdf}, author = {Yanfang Li and Joel C. Huegel and Volkan Patoglu and O{\textquoteright}Malley, M.K.} } @proceedings {9872945, title = {Passive and active kinesthetic perception just-noticeable-difference for natural frequency of virtual dynamic systems}, year = {2008}, note = {

active kinesthetic perception;passive kinesthetic perception;just-noticeable-difference;virtual second order dynamic systems;degree-of-freedom haptic device;haptic sensory feedback;virtual resonance task;visual feedback;

}, month = {03/2008}, pages = {25 - 31}, publisher = {IEEE}, address = {Reno, NE, USA}, abstract = {

This paper investigates the just-noticeable-difference (JND) for natural frequency of virtual second order dynamic systems. Using a one degree-of-freedom haptic device, visual and/or haptic sensory feedback were presented during interactions with the system. Participants were instructed to either perceive passively or actively excite the system in order to discriminate natural frequencies. The JND for this virtual resonance task ranged from 3.99 \% to 6.96 \% for reference frequencies of 1 Hz and 2 Hz. Results show that sensory feedback has a significant effect on JND in passive perception, with combined visual and haptic feedback enabling the best discrimination performance. In active perception, there is no significant difference on JND with haptic and combined visual and haptic feedback. There is also no significant difference between active perception and passive perception for this JND experiment. The presentation of systems with equivalent natural frequencies but different spring stiffness resulted in no large bias toward larger stiffness and no significant difference in JND for equivalent systems. This finding indicates that human participants do not discriminate natural frequency based on the maximum force magnitude perceived, as indicated by prior studies.

}, keywords = {Haptic interfaces, visual perception}, issn = {978-1-4244-2005-6}, doi = {10.1109/HAPTICS.2008.4479908}, url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4479908}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/58-HapticSymposium2008_Li.pdf}, author = {Yanfang Li and Ali Israr and Volkan Patoglu and O{\textquoteright}Malley, M.K.} } @proceedings {073510787453, title = {Towards just noticeable differences for natural frequency of manually excited virtual dynamic systems}, year = {2007}, note = {

Graphical displays;Virtual mass spring systems;Dynamic properties;

}, month = {03/2007}, pages = {569 - 570}, publisher = {IEEE}, address = {Tsukuba, Japan}, abstract = {

This paper explores the experiment design to determine a human{\textquoteright}s ability to discriminate the natural frequency of manually excited virtual dynamic systems. We use a one degree-of-freedom haptic interface with a coupled graphical display to render a virtual mass-spring system, which is excited by the human operator using his/her dominant hand. The results from the preliminary experiment indicate a JND value of approximately 8\%. However, results also indicate that excitation strategies have a significant effect on the discrimination threshold determination of this dynamic property. In this paper, along with a discussion of the preliminary results, a refined experiment design that accounts for different factors influencing the discrimination of manually excited natural frequency is presented. {\textcopyright} 2007 IEEE.

}, keywords = {Display devices, Dynamical systems, Natural frequencies}, doi = {10.1109/WHC.2007.118}, url = {http://dx.doi.org/10.1109/WHC.2007.118}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/59-00\%20-\%20Towards\%20Just\%20Noticeable\%20Differences\%20for\%20Natural\%20Frequency\%20of\%20Manually\%20Excited\%20Virtual\%20Dynamic\%20Systems.pdf}, author = {Yanfang Li and Volkan Patoglu and Huang, Deborah and O{\textquoteright}Malley, M.K.} } @proceedings {li_shared_2006, title = {Shared Control for Training in Virtual Environments: Learning Through Demonstration?}, year = {2006}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/73-00\%20-\%20Li_Patoglu_OMalley_Eurohaptics06.pdf}, author = {Yanfang Li and Volkan Patoglu and O{\textquoteright}Malley, M.K.} } @article {06199869875, title = {Shared control in haptic systems for performance enhancement and training}, journal = {Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME}, volume = {128}, number = {1}, year = {2006}, note = {

Virtual environments;Mass-spring-damper;System dynamics;Shared control;

}, pages = {75 - 85}, chapter = {75}, abstract = {

This paper presents a shared-control interaction paradigm for haptic interface systems, with experimental data from two user studies. Shared control, evolved from its initial telerobotics applications, is adapted as a form of haptic assistance in that the haptic device contributes to execution of a dynamic manual target-hitting task via force commands from an automatic controller. Compared to haptic virtual environments, which merely display the physics of the virtual system, or to passive methods of haptic assistance for performance enhancement based on virtual fixtures, the shared-control approach offers a method for actively demonstrating desired motions during virtual environment interactions. The paper presents a thorough review of the literature related to haptic assistance. In addition, two experiments were conducted to independently verify the efficacy of the shared-control approach for performance enhancement and improved training effectiveness of the task. In the first experiment, shared control is found to be as effective as virtual fixtures for performance enhancement, with both methods resulting in significantly better performance in terms of time between target hits for the manual target-hitting task than sessions where subjects feel only the forces arising from the mass-spring-damper system dynamics. Since shared control is more general than virtual fixtures, this approach may be extremely beneficial for performance enhancement in virtual environments. In terms of training enhancement, shared control and virtual fixtures were no better than practice in an unassisted mode. For manual control tasks, such as the one described in this paper, shared control is beneficial for performance enhancement, but may not be viable for enhancing training effectiveness. Copyright \© 2006 by ASME.

}, keywords = {Control equipment, Damping, Data reduction, Haptic interfaces, Robotics, Robots}, issn = {0022-0434}, doi = {10.1115/1.2168160 }, url = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal\&id=JDSMAA000128000001000075000001\&idtype=cvips\&gifs=yes}, attachments = {https://mahilab.rice.edu/sites/default/files/publications/52-00\%20-\%20JDSMC\%20Shared\%20control.pdf}, author = {O{\textquoteright}Malley, M.K. and Abhishek Gupta and Gen, Matthew and Yanfang Li} } @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.} }