Fall detection device
AssigneeHitachi Metals, Ltd.
InventorsMasaru Noda, Yasunori Abe
Life of this patent
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Abstract
A fall detection device is provided, which accomplishes a fall judgment on acceleration by a simple calculation and improves uniformity of effective threshold value for the acceleration judgment as to a direction of an applied acceleration vector. The fall detection device produces a fall detection signal when an absolute value of each axis component of an acceleration measured by a three-axis acceleration sensor is less than a first threshold value, and when a sum of the absolute values of the axis components of the acceleration is less than a second threshold value that is 1.5 times to twice the first threshold value.
Claims4
A fall detection device comprising:
- a three-axis acceleration sensor for measuring each axis component of an applied acceleration and generating each of axis components of measured acceleration,
- a first comparison means that compares an absolute value of each of the axis components of the measured acceleration with a first threshold value and produces a first output when the absolute value is less than the first threshold value,
- a second comparison means that compares a sum of the absolute values of the axis components of the measured acceleration with a second threshold value and produces a second output when the sum is less than the second threshold value, and
- a fall detection means that produces a fall detection signal when the first comparison means produces the first output and when the second comparison means produces the second output.
Dependencies are inferred from the claim text.