This paper proposes a body posture recognition
system. A portable acceleration sensor module has
been designed and implemented to measure human
body motion. A wavelet-based algorithm has been
proposed to exbstract features from 2-D motion
signals for recognizing human postures. The presented
system can recognize five postures including upstairs,
downstairs, walking, sitting and standing.
Experimental resuls collected from five testers reveal
satisfactory recognition rate except fro the cases of
upstairs and downstairs motion. However, several
limitations are also observed for the system. Firstly,
the motion needs to be smooth. For rapid posture
change and sudden jumps, the recognition rate will
decrease significantly. Secondly, signal transmission
distances are not sufficient. A more powerful RF
module needs to be employed. There also several
places for future improvement. On one hand, the
proceessing time needs to be reduced. For the present
system, it takes about 8 seconds for one cycle. It can
be reduced if less data samples are needed for
recognitiog or a faster data transmission can be used.
On the other hand, dynamic posture recognition can
be achieved if combining more sensors, such as
gyroscopes and accelerometers.