Warning Drivers about Impending Collisions Using Vibrotactile Flow

EEG correlates to perceived urgency elicited by vibration stimulation of the upper body

Conveying information effectively while minimizing user distraction is critical to human-computer interaction. As the proliferation of audio-visual communication pushes human information processing capabilities to the limit, researchers are turning their attention to haptic interfaces. Haptic feedback has the potential to create a desirable sense of urgency that allows users to selectively focus on events/tasks or process presented information with minimal distraction or annoyance. There is a growing interest in understanding the neural mechanisms associated with haptic stimulation. In this study, we aim to investigate the EEG correlates associated with the perceived urgency elicited by vibration stimuli on the upper body using a haptic vest. A total of 31 participants enrolled in this experiment and were exposed to three conditions: no vibration pattern (NVP), urgent vibration pattern (UVP), and very urgent vibration pattern (VUVP). Through self-reporting, participants confirmed that the vibration patterns elicited significantly different levels of perceived urgency (Friedman test, Holm-Bonferroni correction, p < 0.01). Furthermore, neural analysis revealed that the power spectral density of the delta, theta, and alpha frequency bands in the middle central area (C1, Cz, and C2) significantly increased for the UVP and VUVP conditions as compared to the NVP condition (One-way ANOVA test, Holm-Bonferroni correction, p < 0.01). While the perceptual experience of haptic-induced urgency is well studied with self-reporting and behavioral evidence, this is the first effort to evaluate the neural correlates to haptic-induced urgency using EEG. Further research is warranted to identify unique correlates to the cognitive processes associated with urgency from sensory feedback correlates.

Vibrotactile Spatiotemporal Pattern Recognition in Two-Dimensional Space Around Hand

This study investigated vibrotactile spatiotemporal pattern recognition in the two-dimensional space around a hand. The participants placed their hands on the medium, and identified the recognized pattern presented in the medium. There were 64 rotational patterns, presented with sequential impulse vibrations. We investigated how well humans recognized the patterns presented around their hand, and identified the pattern factors (e.g., rotational direction) that affected recognition accuracy. The probability of obtaining correct answers was 48.9 %. It was observed that the start and end points, rotational direction, and the number of vibrations affected recognition accuracy. It was also found that patterns starting or ending on the ulnar side ( 0^°) of the hand were difficult to recognize, whereas those starting or ending on the distal ( 90^°) or proximal side ( 270^°) of the hand were easily recognizable. Furthermore, we found a type of the oblique effect. Patterns starting or ending in the oblique direction were more difficult to recognize than those in the cardinal direction. We also found that the clockwise rotational pattern was slightly easier to recognize than the counterclockwise rotational pattern. Finally, the underestimation of the judgment of tactile numerosity explains how the number of vibrations in the patterns affected the recognition accuracy. This result can be used as a baseline when the recognition of spatiotemporal patterns outside the body under other conditions is examined in future studies.

A Sensaptic ADAS Device Using Shape Memory Alloy Wires: Design and Control

This paper presents an active accelerator pedal system based on an integrated sensor and actuator using shape memory alloy (SMA) for speed control and to create haptics in the accelerator pedal. A device named sensaptics is developed with a pair of bi-functional SMA wires instrumented in a synergistic configuration function as an active sensor for positioning the accelerator pedal (pedal position sensing) to control the vehicle speed through electronic throttle and as a variable impedance actuator to generate active force (haptic) feedback to the driver. The reaction force emanated from the pedal alerts the driver and takes appropriate control action by slowing down the vehicle, in harmony with the road’s condition. The design is developed as a proof-of-concept device and is tested and evaluated in a real-time common rail diesel system for rail pressure regulation and over speeding tests, and the responses and performances are found to be promising.