CARess, a Gentle Touch Informs the Driver

A prototype of Human Machine Interface (HMI) used to deliver information to the driver in cars is described in this paper. The delivery of information is based on the Informative Interruptive Cue (IIC) approach. The interface is a matrix of 4\(\,\times \,\)3 vibrating motors, controlled through a real-time algorithm based on apparent motion and phantom illusion to create continuous and discrete tactile patterns. A first experiment was conducted with 22 participants to examine their ability to discriminate the tactile patterns displayed by the interface placed on the back of a chair. Results showed 61.48 % successful recognition of tactile stimuli. A second experiment based on a free categorisation of the haptic stimuli was performed with another set of 20 participants. The goal was to understand the dimensions of the conceptual space chosen by the participants when telling tactile stimuli apart. Outcomes suggest that parameters such as speed, movement continuity and complexity are used for grouping.