VEHICLE STEERING REVERSAL RATE ALARM SYSTEM
First Claim
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1. In a vehicle having a steering member, automatic driver alertness apparatus comprising:
- reversal sensing means for generating a first signal that is a function of the number of reversals of said steering member;
memory means responsive to said first signal for generating and storing a substantially constant reversal rate signal that is a function of the steering member reversal rate occurring during a first time period; and
alarm means responsive to said first signal and said reversal rate signal subsequent to said first time period for providing an alarm signal when the time averaged rate of said reversals substantially falls below the stored reversal rate.
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Abstract
Pulses, generated by every reversal of a vehicle'"'"''"'"'s steering wheel are counted during a fixed time period to determine a reversal rate when the vehicle exceeds a minimum speed. That rate is stored and a voltage proportional to the rate is used to control the pulse width of subsequent reversal pulses that are applied to a capacitor charging circuit having a long time constant. A high capacitor voltage activates a high reversal rate alarm and a low capacitor voltage activates a low reversal rate alarm.
32 Citations
12 Claims
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1. In a vehicle having a steering member, automatic driver alertness apparatus comprising:
- reversal sensing means for generating a first signal that is a function of the number of reversals of said steering member;
memory means responsive to said first signal for generating and storing a substantially constant reversal rate signal that is a function of the steering member reversal rate occurring during a first time period; and
alarm means responsive to said first signal and said reversal rate signal subsequent to said first time period for providing an alarm signal when the time averaged rate of said reversals substantially falls below the stored reversal rate.
- reversal sensing means for generating a first signal that is a function of the number of reversals of said steering member;
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2. Apparatus according to claim 1 further comprising means responsive to said first signal and said reversal rate signal subsequent to said first time period for providing an alarm signal when the time averaged rate of said reversals substantially exceeds the stored reversal rate.
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3. In a vehicle having a steering member, a speedometer linkage and a brake light circuit, automatic driver alertness apparatus comprising means for generating a pulse train signal in response to the reversals of said steering member, means responsive to said speedometer linkage for providing a signal when said vehicle exceeds a predetermined speed, means initiated by said speed signal and responsive to said reversal signal for determining the steering member reversal rate during a predetermined time period, storing said reversal rate, and providing a signal representative to said reversal rate, and means operative subsequent to said time period and responsive to said reversal signal and said stored reversal rate signal for providing a first alarm signal when the rate of said reversals substantially exceeds said stored reversal rate and a second alarm signal when the rate of said reversals is substantially less than said stored reversal rate.
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4. The apparatus of claim 3 further comprising means connected to said brake light circuit and responsive to said speed signal for providing a reset signal to said rate determining means when said brake light circuit is activated in the absence of a speed signal.
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5. The apparatus of claim 3 wherein said rate determining means includes clock means responsive to said speed signal for providing a signal a predetermined time after the initial receipt of said speed signal, counter means initiated by said speed signal and responsive to said reversal signal and timing signal for counting the pulses in said pulse train until said timing signal is received, and means for generating a control signal proportional to the count in said counter.
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6. The apparatus of claim 5 wherein said alarm means includes means responsive to said control signal and said reversal signal for generating a second train of pulses having pulse widths proportional to said control signal, means responsive to said second train of pulses for integrating said pulse train over a predetermined time period to provide an output signal, means responsive to a predetermined high level of said output signal to provide said first alarm signal, and means responsive to a predetermined low level of said output signal to provide said second alarm signal.
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7. Apparatus according to claim 3 wherein said rate determining circuit includes. left-right shift register means having a pulse initially centrally located therein, up/down counter means activated by said speed signal, clock generator means for providing clock pulses to said counter means, means for applying up count pulses to said counter means when said pulse is in the left hand portion of said counter means, means for applying down count pulses to said counter means when said pulse is in the right hand portion of said counter means, oscillator means responsive to said counter for providing a pulse train having a repetition rate dependent on the count in said counter, means for applying said reversal signal to the left shifting input of said shift register means, means for applying said oscillator pulse train to the right shifting input of said shift register means, and timer means for inhibiting further counting in said counter means after the lapse of a predetermined time period.
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8. The apparatus of claim 6 wherein said alarm means includes means operative subsequent to said time period and connected to said shift register means for activating said first alarm when said pulse is at the one end of said shift register means, and means operative subsequent to said time period and connected to said shift register means for activating said second alarm when said pulse is at the opposite end of said shift register means.
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9. In a vehicle having a steering member, automatic driver alertness apparatus comprising:
- means for generating a signal that is a function of steering member reversals;
means for selectively storing a reversal rate;
means responsive to said signal and to said stored reversal rate for generating pulses in response to said signal, said pulses having a pulse width proportional to the magnitude of said stored reversal rate;
capacitor means receiving said pulses for providing a capacitor charge voltage; and
means for providing an alarm signal when said voltage becomes less than a predetermined value.
- means for generating a signal that is a function of steering member reversals;
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10. A combination of claim 9 further comprising:
- means for providing an alarm signal when said voltage exceeds a predetermined value.
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11. The combination of claim 1 wherein the first signal generated by said reversal sensing means comprises a pulse train having a rate proportional to the number of steering member reversals and said memory means comprises means for counting the pulses in said pulse train during said first time period and for holding said count to provide said stored reversal rate signal.
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12. The combination of claim 11 wherein said alarm means comprises means fOr altering the width of the pulses in said pulse train in accordance with the magnitude of said stored reversal rate signal;
- and further comprising capacitor means receiving said pulses for providing a capacitor charge voltage; and
means for providing said alarm signal when said voltage becomes less than a predetermined value.
- and further comprising capacitor means receiving said pulses for providing a capacitor charge voltage; and
Specification