Relocation detection method and relocation detection unit
View Patent ↗A relocation detection unit includes: an acceleration sensor adapted to detect acceleration generated in the apparatus, an arithmetic section adapted to obtain a first calculation value by performing Nth-order integration on detected value of the acceleration sensor at a predetermined timing, wherein N is a predetermined positive integer, a correction section adapted to obtain a second calculated value by adding/subtracting a specific value to/from the first calculation value at the predetermined timing, and a detection section adapted to detect that the apparatus has been relocated if the second calculated value exceeds a preset reference value.
1. A relocation detection method for detecting relocation of an apparatus comprising the steps of:
providing a relocation detection device comprising an acceleration sensor, a flag setting unit, an arithmetic unit, a correction unit, and a detection unit, wherein the acceleration sensor is attached to the apparatus;
setting a relocation detecting flag in the flag setting unit when the relocation detection device has been turned on;
determining, with the arithmetic unit, in a state that the relocation detecting flag has been cleared, whether the detected values of the acceleration sensor are each within a measuring range, and when the detected values of the acceleration sensor are each within the measuring range, obtaining, with the arithmetic unit, a first calculation value by performing Nth-order integration on the detected values of the acceleration sensor, from which a moving average value obtained from the detected values has been each subtracted for removing an influence of a temperature drift of the acceleration sensor, at a predetermined timing, wherein N is a predetermined positive integer;
obtaining, with the correction unit, a second calculated value by removing an offset value due to an influence of the temperature drift of the acceleration sensor, failed to be removed in the step of obtaining the first calculation value, from the first calculation value at the predetermined timing; and
detecting, with the detection unit, that the apparatus has been relocated if the second calculated value exceeds a preset reference value or any of the detected values of the acceleration sensor is not within the measuring range.
2. The relocation detection method according to claim 1 , wherein the predetermined timing means every time when confirming the detected values of the acceleration sensor, or every predetermined time interval.
3. A relocation detection device to detect relocation of an apparatus, comprising:
an acceleration sensor attached to the apparatus and configured to detect acceleration generated in the apparatus;
a flag setting unit configured to set a relocation detecting flag when power has been turned on;
an arithmetic unit configured to determine, in a state that the relocation detecting flag has been cleared, whether detected values of the acceleration sensor are each within a measuring range and to obtain, when the detected values are each within the measuring range, a first calculation value by performing Nth-order integration on the detected values of the acceleration sensor, from which a moving average value obtained from the detected values has been each subtracted for removing an influence of a temperature drift of the acceleration sensor, at a predetermined timing, wherein N is a predetermined positive integer;
a correction unit configured to obtain a second calculated value by removing an offset value due to an influence of the temperature drift of the acceleration sensor failed to be removed when subtracting the moving average value of the detected values of the acceleration sensor from each of the detected values, from the first calculation value at the predetermined timing; and
a detection unit configured to detect that the apparatus has been relocated if the second calculated value exceeds a preset reference value or any of the detected values of the acceleration sensor is not within the measuring range.
4. The relocation detection device according to claim 3 , wherein the predetermined timing means every time when confirming the detected values of the acceleration sensor, or every predetermined time interval.