While numerous studies have focused on the design of novel controllers and devices to enhance the user experience of teleoperated and virtual environments, our general understanding of what makes a haptic interface acceptable to human operators is limited. The addition of haptic feedback to a computer-mediated task, such as training to perform a surgical procedure in a virtual environment or teleoperating a robot to dispose of explosive ordnance, has been hypothesized to improve the speed, accuracy, and precision of task performance. However, the benefits of haptic feedback have been insufficient to motivate inclusion of haptics in many mission-critical systems. Recent publications in the haptics literature have shown confusing results regarding the role of haptic feedback, such as haptic teleoperators that have high user acceptance and realism ratings but do not have any effect on user performance, as well as haptic teleoperators that are disliked by users yet lead to significant improvements in performance. The PI's goal in this project is to identify the salient parameters of haptic systems leading to haptic realism and haptic utility, their trade-offs, and - hopefully - their complementary features that lead to haptic systems that are realistic and useful, and therefore acceptable to human operators in high-risk scenarios. She plans to approach this problem by examining manipulation and exploration with bilateral teleoperators, where haptic feedback consists of vibrotactile and kinesthetic feedback mediated by a tool. System parameters of interest include feedback gain and frequency content, device mechanical properties, and time delay. For each parameter, the PI will examine its effect on realism and utility, specifically: how users subjectively rate realism and their own performance, and objective measures and theoretical predictions of user perception and performance. In addition, she will survey user acceptance and measure affect, and compare these to measures of realism and utility. Based on these results, she will design and test haptic feedback systems that should maximize user acceptance. This framework will allow her to answer relevant questions such as: What is the spectrum of cost-benefit ratios in bilateral teleoperation, considering the role of device performance in defining the limits of haptic realism and utility? How does the level of risk in a task affect user acceptance of haptic interfaces? Can we design "haptic cartoons" analogous to medical illustrations, which are not completely realistic but display the most important haptic features in order to maximize task performance? And is there a haptic "uncanny valley" in which slightly unrealistic haptic feedback is particularly disturbing to operators?
Broader Impacts: Effective haptic feedback systems will improve human health and well being through applications such as surgery and explosive ordnance disposal. This project will provide the field of computer-mediated haptics with a theoretical and experimental framework to describe the effects of system design choices on user acceptance of tool-based haptic teleoperators. The framework will likely apply to other forms of haptic display (such as sensory substitution and spatially distributed tactile feedback) and in other haptic feedback scenarios (e.g., medical training and the transfer of learning in simulation to real-world tasks). Project outcomes will be disseminated through software and data made publicly available on the PI's laboratory website, a conference workshop, and a new course on haptic design. Outreach programs, public lab tours, and mentoring of female and minority graduate students, undergraduates, and high school students will broaden participation of underrepresented groups in engineering.
