Vibration stimulus of seat belt motor retractor for keeping drivers awake

This paper presents a safety driving system that uses a seat belt motor retractor as a stimulating device for awakening the driver. When the driver becomes drowsy, the motor retractor applies additional tension repetitively in the seat belt to alert the driver. In the experiments using a driving simulator, the driver´s drowsiness was detected by changes in the driver´s eye movements measured by electro-oculography (EOG) and/or changes in facial expression of the driver monitored by the examiners through a video camera and lane deviation. Magnitude, duration, and repetition rate of the additional tension were the major parameters that determined the awakening effect of the stimulus. Exerting additional tension of 130 (N) for three cycles at duration and interval of 100 ms was the most effective pattern for awakening the driver without causing discomfort