Alarm system and method for sensing a stand-by state in a driver drowsiness detection system
First Claim
1. An alarm system for a drowsy vehicle driver comprising:
- a first detector for measuring a first period of time in which vehicle steering is substantially absent, said first detector being responsive to a first period of time longer than a first threshold to produce a first detector signal;
a second detector for detecting a steering adjustment in a single direction, said second detector being responsive to steering adjustments through an angle exceeding a second threshold in the presence of said first detector signal to switch the alarm system to a stand-by state;
a third detector for detecting a preselected steering operational condition while the system is in said stand-by state, and producing an alarm signal in response thereto; and
an alarm means responsive to said alarm signal to produce an alarm to keep the driver awake.
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Accused Products
Abstract
A drowsiness alarm system and method for use in automotive vehicles is set to a stand-by state in response to a specific sequence of steering wheel maneuvers which may reflect driver drowsiness, for example, a relatively long period during which the steering wheel is not turned followed by an abrupt steering adjustment. From the standby state, an alarm or display alerting the driver will be generated in response to another sequence of steering maneuver confirming driver drowsiness. The second sequence of maneuvers may be selected from among a number of conventional steering behavior criteria. If driver drowsiness is not confirmed within a predetermined period of time after initiation of the stand-by state, the system is reset to its initial state.
63 Citations
24 Claims
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1. An alarm system for a drowsy vehicle driver comprising:
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a first detector for measuring a first period of time in which vehicle steering is substantially absent, said first detector being responsive to a first period of time longer than a first threshold to produce a first detector signal; a second detector for detecting a steering adjustment in a single direction, said second detector being responsive to steering adjustments through an angle exceeding a second threshold in the presence of said first detector signal to switch the alarm system to a stand-by state; a third detector for detecting a preselected steering operational condition while the system is in said stand-by state, and producing an alarm signal in response thereto; and an alarm means responsive to said alarm signal to produce an alarm to keep the driver awake. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An alarm system for notifying vehicle driver of drowsiness comprising:
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a first sensor for detecting steering adjustments and producing a first signal including a sensor pulse whenever the steering wheel angular position is adjusted through a given unit angle, said sensor signal being indicative of the direction in which the steering adjustment occurs; a second detector for measuring the period of time between consecutive sensor pulses and producing a second signal indicative of the measured period of time, a third detector responsive to said second signals having a value exceeding a first threshold to produce a third signal; a fourth detector for counting first signals indicative of steering adjustment in the same direction and separated in time by less than a second threshold, said fourth detector producing a fourth signal to switch the system to a stand-by state when its counter value exceeds a third threshold; a fifth detector for detecting a steering operation satisfying a predetermined alarm condition in the presence of said fourth signal to produce an alarm signal; and an alarm means, responsive to said alarm signal, for producing an alarm to keep the vehicle driver awake. - View Dependent Claims (8, 9, 10, 11)
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12. An alarm system for a vehicle driver for producing an alarm in order to prevent the driver from dozing at the wheel, comprising:
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a first detector detecting steering adjustments through an angle exceeding a first threshold and producing a first signal when the steering adjustment is performed in a first direction and a second signal when the steering adjustment is performed in a second direction opposite said first direction, said first detector producing one of said first and second signals whenever the angle of adjustment of the steering wheel exceeds said first threshold; a second detector receiving said first and second signals, measuring intervals between consecutive first and/or second signals to produce an interval-indicative signal indicative of the measured intervals; a third detector which produces a third signal when the interval-indicative signal value exceeds a second threshold; a fourth detector responsive to the interval-indicative signal value being less than a third threshold by counting occurrences of one of said first and second signals as long as the intervals between consecutive occurrences of said one of said first and second signals remain less than said third threshold, said fourth detector comparing its counter value with a fourth threshold and producing a fourth signal indicating a stand-by state when the counter value exceeds said fourth threshold in the presence of said third signal; a fifth detector which produces an alarm signal when a steering operational condition satisfies a predetermined alarm condition in the presence of said stand-by state indicated by said fourth signal; and means for producing an alarm in response to said alarm signal. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A method for detecting the drowsiness of a vehicle driver comprising the steps of:
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detecting occurrences of steering adjustments to detect intervals between occurrences in excess of a first given threshold; detecting occurrences of steering adjustments through angles exceeding a second threshold within a given period of time after the occurrence of intervals exceeding said first given threshold thereby initiating a stand-by state; detecting a specific steering operation in said stand-by state within a period of time less than a third threshold after initiation of said stand-by state; and producing an alarm in response to said specific steering operation occurring after the steering adjustment exceeding said second threshold, whereby a steering adjustment alarm is produced in response to occurrence of said specific steering operation within said third threshold from initiation of a stand-by state. - View Dependent Claims (19, 20, 21, 22)
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23. A method for detecting the drowsiness of a vehicle driver comprising the steps of:
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detecting occurrences of steering adjustments to detect intervals between occurrences in excess of a first given threshold; detecting occurrences of steering adjustments through angles exceeding a second threshold within a given period of time after the occurrence of intervals exceeding said first given threshold thereby initiating a stand-by state; detecting a specific steering operation in said stand-by state; and producing an alarm in response to said specific steering operation occurring after the steering adjustment exceeding said second threshold, whereby a steering adjustment alarm is produced in response to occurrence of said specific steering operation within said third threshold from initiation of a stand-by state. - View Dependent Claims (24)
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Specification