Abstract: Methods and systems for characterizing actual tool usage based on measurements of tool activity are presented herein. In some embodiments, a power tool usage auditor (PTUA) includes a sound measuring device offset from the surface of a power tool. The sound measuring device senses sound waves emitted from the surface of power tool and generates an electrical signal indicative of the sound emitted from the surface of the power tool. In some other embodiments, a PTUA includes a magnetic field measuring device that senses changes in magnetic field induced by motion generated by the power tool. A processor is configured to receive electrical signals indicative of tool activity and generate a signal indicative of actual tool usage. Furthermore, methods and systems for communicating an indication of actual tool usage to a user or another computing system without interfering with the operation of the tool are also presented.

Abstract: Methods and systems for accurately determining a reference orientation of a hand-held object with respect to a reference surface, measuring subsequent movements with respect to the reference orientation, and providing guidance to a user manipulating the object are described herein. A detection device includes a planar, external surface physically located such that the surface is coplanar with a planar, reference surface, such as a work piece. A repeatable reference orientation is established when the external surface is coplanar with the planar surface of the work piece. Subsequent orientation measurement signals are referenced to this orientation for purposes of determining the orientation of the detection device with respect to the work piece. Furthermore, the detection device is coupled to the hand-held object. In this manner, changes in orientation measured by the detection device are indicative of changes in orientation of the hand-held tool relative to the work piece.