FALL DETECTION DEVICE, MAGNETIC DISK DEVICE, AND PORTABLE ELECTRONIC APPARATUS
First Claim
1. A fall detection device for detecting a fall on the basis of an output signal of an acceleration sensor, the fall detection device, comprising:
- a fall start monitoring unit to monitor and determine whether or not the fall detection device is in a fall start state in which a signal indicating a differentiation value of the absolute value of acceleration is lower than a given negative threshold value in a negative direction or is within a given negative range;
a low-gravity transition detection unit to detect whether or not the fall detection device is in a period of transition from the fall start state to a low gravity state in which the signal indicating the absolute value of acceleration is lower than a given threshold value or falls within a given range lower than a value of the stationary state within a given period of time; and
a falling state detection unit to detect a falling state in which the low gravity state continues for a given period of time or longer.
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Accused Products
Abstract
By detecting that a differentiation value of the absolute value of acceleration is lower than a negative threshold value DAth1 in a negative direction from a first stage (S1: Stationary state) where the differentiation value of the absolute value of acceleration is approximately 0, it is considered that the stage is in a second stage (S2: Fall start state). When the absolute value of acceleration after that has become lower from a threshold value Ath1, it is considered that the fall detection device has entered a third stage (S3: Low gravity state). When the low gravity state has continued for a given time T3, it is considered that the stage is in a fourth stage (S4: Falling state), and a fall detection signal is output. Thus, the processing load when the determination is performed by software is reduced and the prediction of a fall can be performed.
23 Citations
16 Claims
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1. A fall detection device for detecting a fall on the basis of an output signal of an acceleration sensor, the fall detection device, comprising:
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a fall start monitoring unit to monitor and determine whether or not the fall detection device is in a fall start state in which a signal indicating a differentiation value of the absolute value of acceleration is lower than a given negative threshold value in a negative direction or is within a given negative range; a low-gravity transition detection unit to detect whether or not the fall detection device is in a period of transition from the fall start state to a low gravity state in which the signal indicating the absolute value of acceleration is lower than a given threshold value or falls within a given range lower than a value of the stationary state within a given period of time; and a falling state detection unit to detect a falling state in which the low gravity state continues for a given period of time or longer. - View Dependent Claims (5, 9, 13)
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2. A fall detection device for detecting a fall on the basis of an output signal of an acceleration sensor, the fall detection device, comprising:
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a fall start monitoring unit to monitor and determine whether or not the fall detection device is in a fall start state in which a signal indicating the absolute value of a differentiation value of acceleration exceeds a given threshold value or is within a given range; a low-gravity transition detection unit to detect whether or not the fall detection device is in a period of transition from the fall start state to a low gravity state in which the signal indicating the absolute value of acceleration is lower than a given threshold value or falls within a given range lower than a stationary state within a given period of time; and a falling state detection unit to detect a falling state in which the low gravity state continues for a given period of time or longer. - View Dependent Claims (6, 10, 14)
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3. A fall detection device for detecting a fall on the basis of an output signal of an acceleration sensor, the fall detection device, comprising:
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a fall start monitoring unit to monitor and determine whether or not the fall detection device is in a fall start state in which a signal indicating a differentiation value of the absolute value of acceleration is lower than a given negative threshold value in a negative direction or is within a given negative range; a low-gravity transition detection unit to detect whether or not the fall detection device is in a period of transition from the fall start state to a low gravity state in which the signal indicating a differentiation value of the absolute value of acceleration is close to 0 relative to a given threshold value within a given period of time; and a falling state detection unit to detect a falling state in which the low gravity state continues for a given period of time or longer. - View Dependent Claims (7, 11, 15)
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4. A fall detection device for detecting a fall on the basis of an output signal of an acceleration sensor, the fall detection device, comprising:
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a fall start monitoring unit to monitor and determine whether or not the fall detection device is in a fall start state in which a signal indicating the absolute value of a differentiation value of acceleration exceeds a given threshold value or is within a given range; a low-gravity transition detection unit to detect whether or not the fall detection device is in a period of transition from the fall start state to a low gravity state in which the signal indicating the absolute value of a differentiation value of acceleration is close to 0 relative to a given threshold value within a given period of time; and a falling state detection unit to detect a falling state in which the low gravity state continues for a given period of time or longer. - View Dependent Claims (8, 12, 16)
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Specification