Method and apparatus for categorizing device use case for on foot motion using motion sensor data

A portable device for categorizing a device use case for the portable device comprising:

• a sensor assembly integrated with the portable device, configured to output data representing motion of the portable device, wherein the motion sensor data comprises measurements output by a motion sensor;
• a categorizer configured to perform at least one of the operations of:
• deriving a use case characteristic from the motion sensor data, wherein the use case characteristic relates to a type of interaction between the portable device and a user;
• determining an effective frequency from the motion sensor data;
• and
• determining an Eigen use case;
• wherein the categorizer determines a device use case for the portable device using the motion sensor data and at least one of the use case characteristic, the effective frequency and the Eigen use case, wherein the device use case comprises a type of interaction between the portable device and a user, and wherein categorizing the device use case of the portable device is based on at least two of the following:
• (i) a statistical analysis of an effective orientation component, wherein orientation is three dimensional and wherein the effective orientation component is a component of orientation that is more affected by the on foot motion of the user than other components of orientation;
• (ii) calculating a radius of rotation value;
• (iii) detecting a pattern of peaks in the motion sensor data;
• and
• (iv) calculating a range of peaks in the motion sensor data;
• and
• a processor configured to run the categorizer.