Gravity axis determination apparatus and mobile terminal apparatus using the same
View Patent ↗A gravity axis determination apparatus which can determine the gravity direction in a short time. The apparatus is low in cost and has a simple construction. Data values of acceleration data trains in a same time zone are mutually compared and one of the three axes is determined as a gravity axis.
1. A gravity axis determination method for determining and detecting one of three axes constructing a three-dimensional space as a gravity axis, comprising:
generating at least two axis acceleration signals each indicating an acceleration in each of directions of at least two axes among said three axes;
and
fetching each of said axis acceleration signals as at least two axis acceleration data trains,
wherein when it is determined a plurality of times consecutively that an axis acceleration data value in one of said axis acceleration data trains is larger than an axis acceleration data value in one of axis acceleration data trains other than said one axis acceleration data train in said same time zone, the axis corresponding to said one axis acceleration data train is determined as said gravity axis.
2. A method according to claim 1 , wherein said plurality of times is at least four times.
3. A method according to claim 2 , wherein each of said acceleration signals is fetched at uniform intervals.
4. A method according to claim 3 , wherein high frequency components of said axis acceleration signal are removed.
5. A method according to claim 2 , wherein high frequency components of said axis acceleration signal are removed.
6. A method according to claim 1 , wherein high frequency components of said axis acceleration signal are removed.