Dynamic Vibrotactile Signals for Forward Collision Avoidance Warning Systems

Abstract

Objective:Four experiments were conducted in order to assess the effectiveness of dynamic vibrotactile collision-warning signals in potentially enhancing safe driving.Background:Auditory neuroscience research has demonstrated that auditory signals that move toward a person are more salient than those that move away. If this looming effect were found to extend to the tactile modality, then it could be utilized in the context of in-car warning signal design.Method:The effectiveness of various vibrotactile warning signals was assessed using a simulated car-following task. The vibrotactile warning signals consisted of dynamic toward-/away-from-torso cues (Experiment 1), dynamic versus static vibrotactile cues (Experiment 2), looming-intensity- and constant-intensity-toward-torso cues (Experiment 3), and static cues presented on the hands or on the waist, having either a low or high vibration intensity (Experiment 4).Results:Braking reaction times (BRTs) were significantly faster for toward-torso as compared to away-from-torso cues (Experiments 1 and 2) and static cues (Experiment 2). This difference could not have been attributed to differential responses to signals delivered to different body parts (i.e., the waist vs. hands; Experiment 4). Embedding a looming-intensity signal into the toward-torso signal did not result in any additional BRT benefits (Experiment 3).Conclusion:Dynamic vibrotactile cues that feel as though they are approaching the torso can be used to communicate information concerning external events, resulting in a significantly faster reaction time to potential collisions.Application:Dynamic vibrotactile warning signals that move toward the body offer great potential for the design of future in-car collision-warning system.

Tactile warning signals for in-vehicle systems

“…Fiel et al, 1991), whose motion direction was congruent with the direction of the potential rear-end collision. Meng et al (2014a) (in press) compared the effectiveness of static tactile cues presented to the hands, static tactile cues presented to the waist, static tactile cues presented simultaneously on the hands and waist, a dynamic toward-torso tactile cue, and a dynamic awayfrom-torso tactile cue in the forward collision avoidance (see Fig. 2).…”

To Beep or Not to Beep?

“…Gray, Ho & Spence [13] however found decreased response times in the tactile modality compared to constant pulses, when looming intensity was combined with apparent motion towards the drivers' head, created by a vertical array of three tactors attached on the abdomen and activated in an upward manner. A variation of apparent motion was tested by Meng et al [26] by activating vibrotactile cues first on participants' hands and then on their torso, creating a sense of cues moving towards the torso. This intervention produced lower response times compared to static cues, while looming intensity of vibration showed again no additional benefits.…”

Informative Collision Warnings: Effect of Modality and Driver Age

“…When the rate of apparent motion was linked to the closing velocity and the direction of apparent motion was towards the head, this warning resulted in significantly shorter BRTs (see also Gray, Ho & Spence, 2014). Similarly, Meng et al (2015a) presented drivers with a FWCS which consisted of vibrotactile signals presented sequentially first at the hands and then immediately to the torso. These dynamic or informative warnings revealed a significant advantage in reducing driver reaction times in contrast to signals that were activated simultaneously or signals that simulated motion away from the driver (see also Meng et al, 2015b).…”