PROBLEM TO BE SOLVED: To provide an awakening degree calculation device capable of improving the detection accuracy of sleepiness.SOLUTION: The awakening degree calculation device sets a circadian variation in each driver and executes weight function calculation processing in which a weight function for correcting an awakening degree estimated on the basis of a photographed image shows a correspondence relation between a time since a mounted vehicle starts traveling and a correction coefficient and a calculation is made so that influence on an awakening degree due to low reliability of a reference value may be reduced until a second regulated time passes and so that influence exercised on a corrected awakening degree from the weight coefficient may be always constant after the second regulated time passes (S110). Then, an estimation index and a reference value are set (S150), and an awakening degree is calculated according to the estimation index and the reference value (S160). A corrected awakening degree obtained by multiplying the calculated awakening degree by the correction coefficient at the present time is calculated (S170), and warning processing based on the corrected awakening degree is executed (S180).COPYRIGHT: (C)2008,JPO&INPIT【課題】眠気の検知精度を向上させることが可能な覚醒度算出装置の提供。【解決手段】覚醒度算出装置では、運転者毎の日内変動を設定すると共に、撮影画像に基づいて推定される覚醒度を補正するための重み関数を、搭載車両が運転を開始されてからの時間と、補正係数との対応関係を示し、かつ第二規定時間が経過するまでは、基準値の信頼性が低いことによる覚醒度への影響が低減されたものとなり、第二規定時間が経過した以降では、重み係数から補正覚醒度が受ける影響が常に一定となるように算出する重み関数算出処理を実行する(S110)。そして、撮影画像に基づいて、推定指標、及び基準値を設定し(S150)、それらに従って覚醒度を算出する(S160)。さらに、算出された覚醒度に、現在の時刻における補正係数を乗じた補正覚醒度を算出し(S170)、補正覚醒度に基づく警告処理を実行する(S180)。【選択図】図2
