Improving mobile robot control — Negative feedback for touch interfaces

Touch screen technology has become pervasive in the consumer product arena over the last decade. It offers some distinct advantages over traditional interfaces, including the removal of space consuming peripherals such as mice, keyboards, and joysticks from a system's design. However, there are significant drawbacks to these devices that have limited their adoption by so-called power users. Most notably, touch screens demand the user's visual attention and require them to look at the input device to avoid pressing the wrong button. Based on these observations we propose a simple system that augments an existing touch screen device to provide the user with negative feedback for touch interfaces (NFTI). This is accomplished by vibrotactile feedback that is triggered when an inactive part of the screen is accidentally touched. The goal is to simulate a touch-typing experience that could traditionally be found on a hard keyboard interface, while simultaneously retaining many of the benefits of touch screen technology. The primary contribution of this paper is to present the results of a usability study, which considers a benchmark task of tele-operation that demands the user's visual attention. We found that in nearly all cases, performance improved with NFTI. Perhaps more importantly, the addition of negative feedback did not adversely impact the user's workload. In fact, according to the exit survey, nearly 90% users prefer NFTI over conventional touch screen devices.