Method and apparatus for detecting free fall of mobile device and recording medium storing computer program for executing the method
A method, an apparatus and a computer readable recording medium storing a program for correctly detecting a free fall by referring to an acceleration and an integration of the acceleration. The method includes sensing an acceleration of the mobile device; integrating the sensed acceleration with respect to time; and determining the free fall by comparing the result of the integrating with a predetermined area threshold.
1 . A method of detecting a free fall of a device, the method comprising:
sensing an acceleration of the device;
integrating a sensed acceleration with respect to time; and
detecting the free fall by comparing a result of the integrating with a predetermined area threshold.
2 . The method of claim 1 , wherein the integrating the sensed acceleration is performed if the sensed acceleration is less than a predetermined acceleration threshold.
3 . The method of claim 2 , wherein the integrating the sensed acceleration is initiated if the sensed acceleration is greater than a predetermined acceleration threshold.
4 . The method of claim 1 , wherein the detecting the free fall further comprising generating a free fall alarm if the result of the integrating is greater than a predetermined area threshold.
5 . The method of claim 4 , wherein the detecting the free fall comprises comparing the result of the integrating for a predetermined time threshold with a predetermined area threshold.
6 . The method of claim 1 , wherein the sensed acceleration is an acceleration vector obtained by performing a square root operation on the acceleration.
7 . An apparatus for detecting a free fall of a device, the apparatus comprising:
an acceleration sensor which senses an acceleration of the device;
an integrating unit which integrates the acceleration sensed by the acceleration sensor; and
an free fall detecting unit which detects the free fall by comparing an output of the integrating unit with a predetermined area threshold;
8 . The apparatus of claim 7 , wherein the integrating unit starts to integrate the output of the acceleration sensor if the acceleration is less than a predetermined acceleration threshold.
9 . The method of claim 8 , wherein the integrating unit is initiated to integrate the output of the acceleration sensor if the acceleration is greater than a predetermined acceleration threshold.
10 . The apparatus of claim 7 , wherein the free fall detecting unit begins to detect the free fall if a predetermined time threshold has elapsed after the integrating unit started integrating the acceleration.
11 . The apparatus of claim 7 , wherein the integrating unit integrates an acceleration vector obtained by performing a square root operation on the acceleration.
12 . A computer readable recording medium storing a program to execute a method of detecting a free fall of a device, the method comprising:
sensing an acceleration of the device;
integrating a sensed acceleration if the sensed acceleration is less than a predetermined acceleration threshold;
comparing a result of the integrating with a predetermined area threshold; and
generating a free fall alarm based on a result of the comparing.