Vibrotactile "On-Thigh" Alerting System in the Cockpit

BACKGROUND Alerts in the cockpit must be robust, difficult to ignore, and easily recognized. Tactile alerts can provide means to direct the pilot's attention in the already visual-auditory overloaded cockpit environment. OBJECTIVE This research examined the thigh as a placement for vibrotactile display in the cockpit. The authors (a) report initial findings concerning the loci and properties of the display, (b) evaluate the added value of tactile cuing with respect to the existing audiovisual alerting system, and (c) address the issue of tactile orienting--whether the cue should display "flight" or "fight" orienting. The tactor display prototype was developed by a joint venture of Israel Aerospace Industries, Lahav Division, and the Ben Gurion University of the Negev (patent pending 11/968,405). A vibrotactile display mounted on the thigh provided directional cues in the vertical plane. Two vibrotactile display modes (eight and four tactors) and two response modes (compatible, i.e., fight [toward vibrotactile cue], and inverse, i.e., flight [away from vibrotactile cue]) were evaluated. RESULTS Vertical directional orienting can be achieved by a vibrotactile display assembled on the thigh. The four-tactor display mode and the compatible response mode produced more accurate results. CONCLUSION Tactile cues can provide directional orienting in the vertical plane. The benefit of adding compatible tactile cues compared with visual and auditory cues alone has yet to be reinforced. Nevertheless, fight mode, that is, directing the way to escape from hazardous situations, was preferred. APPLICATION Potential applications include providing directional collision alerts within the vertical plane, assisting pilot's elevation control, or navigation.