Wakefulness estimating apparatus and method
First Claim
1. An apparatus for estimating wakefulness of a driver comprising:
- a frequency analyzing process unit, for calculating an average value of a quantities of the frequency power components as a quantity of high frequency components, wherein the quantities of the frequency power components are calculated by a frequency transformation of displacements of a vehicle in the width direction detected as a time series, and for calculating a maximum value of the quantities of frequency power components within a predetermined frequency range as a quantity of low frequency components, wherein the predetermined frequency range includes a stagger frequency exposed when the driver is at a low level of wakefulness;
an estimated wakefulness value calculation unit for calculating an estimated value of wakefulness from the ratio of the quantity of high frequency components to the quantity of low frequency components; and
an alarm control unit for setting an imaginary deviation line between a lane marking extending on a side the vehicle and the vehicle with a predetermined interval from the lane marking according to the estimated value of wakefulness and issues an alarm when a deviation from the imaginary deviation line occurs.
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Accused Products
Abstract
An estimated value of wakefulness is calculated from the ratio between the quantity of high frequency components and the quantity of low frequency components obtained by performing frequency transformation of vehicle displacements (S51). An imaginary deviation line is set between a lane marking and the vehicle according to the estimated value of wakefulness (S55, S59, S62, S66), and an alarm is issued when the vehicle deviates from the imaginary deviation line. Since the alarm is issued when the vehicle is at a predetermined distance from the lane marking, alarming can be performed at substantially constant timing.
20 Citations
12 Claims
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1. An apparatus for estimating wakefulness of a driver comprising:
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a frequency analyzing process unit, for calculating an average value of a quantities of the frequency power components as a quantity of high frequency components, wherein the quantities of the frequency power components are calculated by a frequency transformation of displacements of a vehicle in the width direction detected as a time series, and for calculating a maximum value of the quantities of frequency power components within a predetermined frequency range as a quantity of low frequency components, wherein the predetermined frequency range includes a stagger frequency exposed when the driver is at a low level of wakefulness;
an estimated wakefulness value calculation unit for calculating an estimated value of wakefulness from the ratio of the quantity of high frequency components to the quantity of low frequency components; and
an alarm control unit for setting an imaginary deviation line between a lane marking extending on a side the vehicle and the vehicle with a predetermined interval from the lane marking according to the estimated value of wakefulness and issues an alarm when a deviation from the imaginary deviation line occurs. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of estimating wakefulness of a driver based on a calculated level of wakefulness comprising:
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a first step for calculating quantities of frequency power components by a frequency transformation of displacements of a vehicle in the width direction detected as a time series;
a second step for calculating an average value of the quantities of frequency power components calculated in the first step as a quantity of high frequency components;
a third step for calculating a maximum value of the quantities of frequency power components within a predetermined frequency range as a quantity of low frequency components, wherein the predetermined frequency range includes a stagger frequency exposed when the driver is at a low level of wakefulness;
a fourth step for calculating an estimated value of wakefulness from the ratio of the quantity of high frequency components to the quantity of low frequency components; and
a fifth step for setting an imaginary deviation line between a lane marking extending on a side of the vehicle and the vehicle according to the estimated value of wakefulness and issuing an alarm when a deviation from the imaginary deviation line occurs. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification