졸음운전자의 각성을 위한 햅틱 경고신호의 설계 및 평가

Abstract

Objective: This study is to design optimal haptic warning signal to secure awareness of drowsy driver and evaluate its alertness compared with the auditory signal. Background: As drowsy driving is one of the causes of fatal traffic accidents, the vehicle needs an assistant system that can monitor the driver's drowsiness and give warnings to arouse in case of drowsy driving. It is important to design and utilize effective warning signals in a drowsy driving warning system (DDWS) for fast and clear response of the driver. Under certain circumstances like public transportations, haptic display is more appropriate for silent and private communication between the system and the driver. Method: Experiments were conducted to evaluate alertness of warning signals in terms of response rate and time in a simulated driving environment. Subjects participated in the experiments for comparing the alertness for 3 haptic signals with 1 auditory signal. Different haptic signals modulated by its frequencies of 2, 5, and 8Hz were given in random order when a valid DDWS identified the subjects' drowsiness defined in two levels (light and heavy). Results: The response rate of the haptic signals (90%) was significantly lower than that of the auditory signal (97%) under light drowsy condition, but haptic signal of 2Hz got fastest response time (1,390msec) among the signals. The difference in the response time was statistically significant among the haptic signals but it is not for auditory signal. The response time of 2Hz haptic signal was found as competitive in heavy drowsy condition. Conclusion: It is found that haptic signals with different design parameters can make differences in alertness of drowsy driver and in case of this study the best option was of 2Hz. Application: The Haptic signal is going to be implemented in a DDWS and tested for its alertness in real vehicle conditions.