Center for Embedded Network Sensing

While cameras have the potential to enable many applications in sensor networks, to be effective they must first be externally calibrated. In prior systems, cameras, identified by controllable light sources, utilized angular measurements amongst themselves to determine their relative positions and orientations. However, the typical camera’s narrow field of view makes such systems susceptible to failures in the presence of occlusions or non-ideal configurations. Actuation-assistance helps to overcome such issues by essentially broadening each camera’s view. In this paper we discuss and implement a prototype system that uses actuation to aid in the external calibration of camera networks. We evaluate our system using simulations and a testbed of MicaZ nodes, equipped with Cyclops camera modules mounted on custom pan-tilt platforms. Our results show that actuation-assistance can dramatically reduce node density requirements.