| US 7,571,847 B2 | ||
| Apparatus for measuring number of footsteps and method thereof | ||
| Woo-jong Lee, Suwon-si (Korea, Republic of); and Sang-on Choi, Suwon-si (Korea, Republic of) | ||
| Assigned to Samsung Electro-Mechanics Co., Ltd, Suwon-si (Korea, Republic of) | ||
| Filed on Oct. 18, 2005, as Appl. No. 11/251,887. | ||
| Claims priority of application No. 10-2004-0094963 (KR), filed on Nov. 19, 2004. | ||
| Prior Publication US 2006/0111843 A1, May 25, 2006 | ||
| Int. Cl. G01C 22/00 (2006.01) | ||
| U.S. Cl. 235—105 [235/375] | 22 Claims |
| 1. An apparatus for measuring a number of footsteps, the apparatus comprising:
a terrestrial magnetism sensing unit which outputs digital values of at least two of an X-axis, a Y-axis and a Z-axis, within
a predetermined sampling time interval according to movement of a body;
a reference digital value generator which generates a reference digital value based on N digital values of each axis output
from the terrestrial magnetism sensing unit, (N−1) digital values of each axis output from the terrestrial magnetism sensing
unit in one sampling time interval before the N digital values are output, and (N−2) digital values of each axis output from
the terrestrial magnetism sensor in one sampling time interval before the (N−1) digital values output;
a reference axis selector which searches for an N digital value of an axis having a maximum amplitude in a predetermined period
among the N digital values of each axis output and selects an axis having the maximum amplitude as a reference axis;
a digital value determiner which determines whether the N digital value of the reference axis is larger than a reference digital
value of the reference axis by a predetermined value; and
a controller which determines the movement of the body is an ascending movement of one footstep, if the N digital value is
larger than the reference digital value by a predetermined value.
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