Low cost optical motion sensors: an experimental characterization

Low-cost optical motion sensors commonly used in computer mice are experimentally characterized in view of their use as multiple degree of freedom sensors for industrial applications. Each non-contact optical sensor provides two output channels giving x and y components of the device relative displacement. The experimental activity presented in the paper shows that limitations mainly arise from the device sensitivity to the reference surface texture and from the upper limited working speed. It is shown that, for an effective application, the surface over which the sensor is moving must be cooperative. In case of a typical commercial device working on a white surface, the linearity error evaluated over a single pass trajectory of 200mm is about 0.1% whilst the variability due to the reference surface pattern orientation is of 2%.