Crash detection apparatus of air bag system
First Claim
1. A crash detection apparatus of an air bag system comprising:
- a detection means for detecting acceleration caused therein by an automobile and outputting electric signals corresponding to the acceleration;
a discrimination means for discriminating, from the signals from said detection means, a crash signal which is outputting on the basis of the acceleration caused by crash of the automobile, said crash signal being inputted into an inflator to inflate an air bag;
wherein said detection means is a capacitance type semiconductor detector comprising a fixed electrode and a movable electrode disposed to oppose said fixed electrode, and a servo control means is electrically connected to said detection means to form a feedback loop for detection of acceleration and to apply electric energy to said detection means so that electrostatic force is applied between said fixed electrode and said movable electrode to maintain an initial position of said movable electrode; and
wherein a diagnostic means is provided for diagnosing said crash detection apparatus on whether or not said crash detection apparatus functions correctly by applying an electric signal for diagnosis to said feedback loop of said servo control means so as to apply electrostatic force between said fixed electrode and said movable electrode for diagnosis.
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Accused Products
Abstract
A crash detection apparatus of an air bag system comprises a detection unit for detecting acceleration caused therein by an automobile and outputting electric signals corresponding to the acceleration, a discrimination unit for discriminating, from the signals from the detection unit, a crash signal which is outputted on the basis of the acceleration caused by crash of the automobile, the crash signal being inputted into an inflator to inflate an air bag. The detection unit is a capacitance type semiconductor detector comprising a pair of fixed electrodes and a cantilevered movable electrode disposed between the fixed electrodes and fixed at an end thereof, and a servo control unit is electrically connected to the detection unit so as to form a negative feedback loop, of a detection signal. The servo control unit serves for applying electric energy temporarily to the detection unit to cause electrostatic force in the detection means for restricting movement of the movable electrode caused by acceleration at an initial position thereof. A diagnostic unit is provided for diagnosing the crash detection apparatus on whether or not the crash detection apparatus functions correctly, the diagnostic unit being electrically connected to the servo control unit to input a diagnostic signal to the negative feedback loop thereby to apply electrostatic force for diagnosis between the fixed electrode and the movable electrode.
32 Citations
16 Claims
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1. A crash detection apparatus of an air bag system comprising:
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a detection means for detecting acceleration caused therein by an automobile and outputting electric signals corresponding to the acceleration; a discrimination means for discriminating, from the signals from said detection means, a crash signal which is outputting on the basis of the acceleration caused by crash of the automobile, said crash signal being inputted into an inflator to inflate an air bag; wherein said detection means is a capacitance type semiconductor detector comprising a fixed electrode and a movable electrode disposed to oppose said fixed electrode, and a servo control means is electrically connected to said detection means to form a feedback loop for detection of acceleration and to apply electric energy to said detection means so that electrostatic force is applied between said fixed electrode and said movable electrode to maintain an initial position of said movable electrode; and wherein a diagnostic means is provided for diagnosing said crash detection apparatus on whether or not said crash detection apparatus functions correctly by applying an electric signal for diagnosis to said feedback loop of said servo control means so as to apply electrostatic force between said fixed electrode and said movable electrode for diagnosis. - View Dependent Claims (2, 3, 4)
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5. A crash detection apparatus of an air bag system comprising:
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a detection means for detecting acceleration caused therein by an automobile and outputting electric signals corresponding to the acceleration; a discrimination means for discriminating, from the signals from said detection means, a crash signal which is outputted on the basis of the acceleration caused by crash of the automobile, said crash signal being inputted into an inflator to inflate an air bag; wherein said detection means is a capacitance type semiconductor detector comprising a pair of fixed electrodes and a movable electrode between said fixed electrodes, and a servo control means is electrically connected to said detection means so as to form a negative feedback loop of a detection signal, said servo control means being for applying electric energy to said detection means to cause electrostatic force in said detection means for restricting movement of said movable electrode caused by acceleration at an initial position thereof; and wherein a diagnostic means is provided for diagnosing said crash detection apparatus on whether or not said crash detection apparatus functions correctly, said diagnostic means being electrically connected to said servo control means to input a diagnostic signal temporarily to said negative feedback loop so as to apply electrostatic force for diagnosis between said fixed electrode and said movable electrode. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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12. An acceleration detection apparatus of an automobile comprising:
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a detection means for detecting acceleration caused therein by an automobile and outputting electric signals corresponding to the acceleration; a discrimination means for discriminating, from the signals from said detection means, a signal which is outputted on the basis of acceleration higher than a predetermined level; wherein said detection means is a capacitance type semiconductor detector comprising a pair of fixed electrodes and a movable electrode disposed between said fixed electrodes, and a servo control means is electrically connected to said detection means so as to form a negative feedback loop of a detection signal, said servo control means being for applying electric energy to said detection means to cause electrostatic force in said detection means for restricting movement of said movable electrode caused by acceleration at an initial position thereof; and wherein a diagnostic means is provided for diagnosing said acceleration detection apparatus on whether or not said detection apparatus functions correctly, said diagnostic means being electrically connected to said servo control means to input a diagnostic signal to said negative feedback loop to apply electrostatic force for diagnosis between said fixed electrode and said movable electrode. - View Dependent Claims (13, 14, 16)
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15. A crash detection apparatus of an air bag system comprising:
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a detection means for detecting acceleration caused therein by an automobile and outputting electric signals corresponding to the acceleration; a discrimination means for discriminating, from the signals from said detection means, a crash signal which is outputted on the basis of the acceleration caused by crash of the automobile, said crash signal being inputted into an inflator to inflate an air bag; wherein said detection means comprises a movable electrode and a servo control means is electrically connected to said detection means so as to form a negative feedback loop of a detection signal, said servo control means applying electric energy to said detection means to cause electrostatic force in said detection means for restricting movement of said movable electrode caused by acceleration at an initial position thereof; and wherein a diagnostic means is provided for diagnosing said crash detection apparatus on whether or not said crash detection apparatus functions correctly, said diagnostic means being electrically connected to said servo control means to input a diagnostic signal temporarily to said negative feedback loop to apply the electrostatic force for diagnosis to said movable electrode.
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Specification