Patent ID: 7421369

Claim:
An activity recognition apparatus for detecting an activity of a subject, the apparatus comprising: a sensor unit including a plurality of linear motion sensors configured to detect linear motions and a plurality of rotational motion sensors configured to detect rotational motions, the linear motions being orthogonal to each other, the rotational motions being orthogonal to each other; and a computational unit configured to receive and process signals from the sensors included in the sensor unit so as to detect an activity of the subject, wherein the sensor unit is configured to be directly or indirectly supported by the subject with an arbitrary orientation with respect to the subject, the computational unit is configured to perform a calculation that uses the signals from the linear motion sensors and rotational motion sensors to determine the activity of the subject independent of the arbitrary orientation of the sensor unit; and the computational unit is further configured to detect a rotation of the sensor unit by calculating a first rotation by integrating the signals from the rotational motion sensors, calculating a second rotation by using a gravitation model and the signals from the linear motion sensors, and performing weighted interpolation of the first rotation and the second rotation.