Investigating the Usability of a Vibrotactile Torso Display for Improving Simulated Teleoperation Obstacle Avoidance

While unmanned ground vehicle (UGV) teleoperation is advantageous in terms of adaptability and safety, it introduces challenges resulting from the operator\u27s poor perception of the remote environment. Previous literature on the ability of haptic feedback to augment visual displays indicates that UGV obstacle avoidance information may be more meaningfully communicated via vibrotactile torso systems. Presenting this information so that operators can accurately detect the proximity from walls and obstructions could result in a significant reduction in errors, ultimately improving task performance and increasing the usability of teleoperation. The goal of the current study was to determine the degree to which a vibrotactile torso belt could improve UGV teleoperation performance over video feed alone in a simulated environment. Sixty operators controlled a UGV using a simulated video feed, while half also utilized a vibrotactile belt. Results indicated that the vibrotactile display did not improve navigational performance or decrease subjective workload over video feed alone. Possible reasons for this and limitations are discussed

Effects of Interaction with an Immersive Virtual Environment on Near-field Distance Estimates

Distances are regularly underestimated in immersive virtual environments (IVEs) (Witmer & Kline, 1998; Loomis & Knapp, 2003). Few experiments, however, have examined the ability of calibration to overcome distortions of depth perception in IVEs. This experiment is designed to examine the effect of calibration via haptic and visual feedback on distance estimates in an IVE. Participants provided verbal and reaching distance estimates during three sessions; a baseline measure without feedback, a calibration session with visual and haptic feedback, and finally a post-calibration session without feedback. Feedback was shown to calibrate distance estimates within an IVE. Discussion focused on the possibility that costly solutions and research endeavors seeking to remedy the compression of distances may become less necessary if users are simply given the opportunity to use manual activity to calibrate to the IVE

Investigation of Distance to Break Using Compliant Nonlinear and Linear Materials in a Simulated Minimally Invasive Surgery Task

Accurate interpretation of the mediated haptic information in minimally invasive surgery (MIS) is critical for applying appropriate force magnitudes into soft tissue with the aim of minimizing tissue trauma. Force perception in MIS is a dynamic process with surgeon\u27s administration of force into tissue revealing information about the remote surgical site which will further inform the surgeon for additional haptic interaction. The relationship between applied force and material deformation rate has been shown to provide biomechanical information specifying the distance remaining until the tissue would fail, which has been termed distance-to-break (DTB). The current study continues the investigation of whether observers can use DTB to stop before a tissue\u27s failure point. Similar to past results, observers could reliably perceive DTB in simulated nonlinear biological tissues

Aperture passability judgments in novice walker users: The impact of action scaling above and beyond body scaling

Many older adults who use assistive walking devices to improve stability and locomotion also report falls while using their device. The present study investigated how walking devices alter the perception-action system of the user. Specifically, the study assessed how walker users perceive their ability to pass through a doorway. One’s ability to pass through an aperture is constrained by their widest frontal dimension (body-scaling) and the dynamic properties of the individual in motion (action-scaling). In order to compare the unique impacts of body-scaling and action-scaling, novice users of a standard walker, wheeled walker, cane, or no device (control) made static and dynamic judgments of aperture passability while their lateral motion variability was recorded. Hierarchical Linear Modeling revealed that novice users successfully scaled their passability judgments to the width of the walker, and that the introduction of movement for the dynamic judgments resulted in more conservative perceptions of passability. Unexpectedly, motion variability was not a significant predictor of passability judgments, which suggests that the self-motion produced during dynamic judgments revealed additional environmental information (rather than intrinsic dynamic information) and allowed for the application of a margin of safety. Results of this study suggest that experience using the walking device is an important factor in ensuring new users understand their action capabilities and avoid injurious collisions and falls

SPATIAL PERCEPTION AND ROBOT OPERATION: THE RELATIONSHIP BETWEEN VISUAL SPATIAL ABILITY AND PERFORMANCE UNDER DIRECT LINE OF SIGHT AND TELEOPERATION

This dissertation investigated the relationship between the spatial perception abilities of operators and robot operation under direct-line-of-sight and teleoperation viewing conditions. This study was an effort to determine if spatial ability testing may be a useful tool in the selection of human-robot interaction (HRI) operators. Participants completed eight cognitive ability measures and operated one of four types of robots under tasks of low and high difficulty. Performance for each participant was tested during both direct-line-of-sight and teleoperation. These results provide additional evidence that spatial perception abilities are reliable predictors of direct-line-of-sight and teleoperation performance. Participants in this study with higher spatial abilities performed faster, with fewer errors, and less variability. In addition, participants with higher spatial abilities were more successful in the accumulation of points. Applications of these findings are discussed in terms of teleoperator selection tools and HRI training and design recommendations with a human-centered design approach

FEELING FOR FAILURE: HAPTIC FORCE PERCEPTION OF SOFT TISSUE CONSTRAINTS IN A SIMULATED MINIMALLY INVASIVE SURGERY TASK

In minimally invasive surgery (MIS), the ability to accurately interpret haptic information and apply appropriate force magnitudes onto soft tissue is critical for minimizing bodily trauma. Force perception in MIS is a dynamic process in which the surgeon\u27s administration of force onto tissue results in useful perceptual information which guides further haptic interaction and it is hypothesized that the compliant nature of soft tissue during force application provides biomechanical information denoting tissue failure. Specifically, the perceptual relationship between applied force and material deformation rate specifies the distance remaining until structural capacity will fail, or indicates Distance-to-Break (DTB). Two experiments explored the higher-order relationship of DTB in MIS using novice and surgeon observers. Findings revealed that observers could reliably perceive DTB in simulated biological tissues, and that surgeons performed better than novices. Further, through calibration feedback training, sensitivity to DTB can be improved. Implications for optimizing training in MIS are discussed

Perceiving Soft Tissue Break Points in the Presence of Friction

In minimally invasive surgery (MIS), surgeons face several perceptual challenges due to the remote interaction with the environment, such as distorted haptic feedback through the instruments due to friction produced from the rubber trocar sealing mechanisms at the incision site. As a result, surgeons sometimes unintentionally damage healthy tissues during MIS due to excessive force. Research has demonstrated that useful information is available in the haptic array regarding soft tissues, which allows novices to successfully perceive the penetration distance remaining until a material will fail based on displacement and reactionary forces of simulated tissues using a haptic invariant, Distance-to-Break (DTB). Attunement and calibration training was used in the current study to investigate whether observers are able to identify material break points in nonlinear compliant materials through haptic force application, while ignoring haptic stimulation not lawfully related to the properties specifying DTB, including friction. A pretest, feedback, posttest, and transfer-of-training phase design allowed participants to probe four virtually simulated materials at varying levels of friction: no friction, low friction, and high friction in the first experiment, and pull the simulated tissues in the second experiment to investigate if perception of DTB generalizes to other tasks used in MIS. Experiment 1 revealed that sensitivity to DTB can be improved through training, even in the presence of friction, and that friction may assist observers to perceive fragile tissues that otherwise would be below perceptual threshold. Experiment 2 revealed that attunement and calibration to DTB also transfers to pulling motions

Just Around the Corner: The Impact of Instruction Method and Corner Geometry on Teleoperation of Virtual Unmanned Ground Vehicles

Teleoperated robots have proven useful across various domains, as they can more readily search for survivors, survey collapsed and structurally unsound buildings, map out safe routes for rescue workers, and monitor rescue environments. A significant drawback of these robots is that they require the operator to perceive the environment indirectly. As such, camera angles, uneven terrain, lighting, and other environmental conditions can result in robots colliding with obstacles, getting stuck in rubble, and falling over (Casper & Murphy, 2003). To better understand how operators remotely perceive and navigate unmanned ground vehicles, the present work investigated operators’ abilities to negotiate corners of varying widths. In Experiment 1, we evaluated how instruction method impacts cornering time and collisions, looking specifically at the speed-accuracy tradeoff for negotiating corners. Participants navigated a virtual vehicle around corners under the instruction to focus on accuracy (i.e., avoiding collisions) or speed (i.e., negotiating the corners as quickly as possible). We found that as the task became more difficult, subjects’ cornering times increased, and their probability of successful cornering decreased. We also demonstrated that the Fitts’ law speed-accuracy tradeoff could be extended to a cornering task. In Experiment 2, we challenged two of the assumptions of Pastel et al.’s (2007) cornering law and assessed how corner angle and differences in path widths impacted cornering time. Participants navigated a virtual vehicle around corners of varying angles (45°, 90°, and 135°) and varying path widths. We found that increases in corner angle resulted in increased cornering times and a decreased probability of successful cornering. The findings from these experiments are applicable to contexts where an individual is tasked with remotely navigating around corners (e.g., video gaming, USAR, surveillance, military operations, training)

Data visualization in the first person

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, February 2013.Cataloged from PDF version of thesis. "February 2013."Includes bibliographical references (p. 103-107).This dissertation will examine what a first person viewpoint means in the context of data visualization and how it can be used for navigating and presenting large datasets. Recent years have seen rapid growth in Big Data methodologies throughout scientific research, business analytics, and online services. The datasets used in these areas are not only growing exponentially larger, but also more complex, incorporating heterogeneous data from many sources that might include digital sensors, websites, mass media, and others. The scale and complexity of these datasets pose significant challenges in the design of effective tools for navigation and analysis. This work will explore methods of representing large datasets as physical, navigable environments. Much of the related research on first person interfaces and 3D visualization has focused on producing tools for expert users and scientific analysis. Due to the complexities of navigation and perception introduced by 3D interfaces, work in this area has had mixed results. In particular, considerable efforts to develop 3D systems for more abstract data, like file systems and social networks, have had difficulty surpassing the efficiency of 2D approaches. However, 3D may offer advantages that have been less explored in this context. In particular, data visualization can be a valuable tool for disseminating scientific results, sharing insights, and explaining methodology. In these applications, clear communication of concepts and narratives are often more essential than efficient navigation. This dissertation will present novel visualization systems designed for large datasets that include audio-video recordings, social media, and others. Discussion will focus on designing visuals that use the first person perspective to give a physical and intuitive form to abstract data, to combine multiple sources of data within a shared space, to construct narratives, and to engage the viewer at a more visceral and emotional level.by Philip DeCamp.Ph.D