Patent ID: 7034697
Filing Date: 2006-04-25
Classification: G08B

Abstract:
1. An awakening level estimation apparatus for vehicle comprising: a signal processing part for calculating each frequency component power by making frequency conversion of a displacement amount of a vehicle in a direction of vehicle width detected in a time series manner; a frequency component amount calculation part for calculating an average value of the frequency component powers calculated by the signal processing part as a high frequency component amount and also calculating a maximum value of the frequency component powers within a predetermined frequency domain including a stagger frequency to become apparent in a state in which an awakening level of a driver decreases as a low frequency component amount; a correction factor calculation part for calculating a high frequency percentile value in which the proportion of the total sum to the sum of incidences counted from the lower frequency component powers results in a predetermined proportion in a histogram of the high frequency component amount and calculating a low frequency percentile value in which the proportion of the total sum to the sum of incidences counted from the lower frequency component powers results in a predetermined proportion in a histogram of the low frequency component amount and calculating a correction factor based on the high frequency percentile value and the low frequency percentile value; an evaluation value calculation part for calculating an evaluation value by correcting a ratio between the high frequency component amount and the low frequency component amount by the correction factor; and a decision part for deciding an awakening level of a driver based on the evaluation value.