  This work explores the application of nonlinear oscillators coupled by
electric field in water for collective tasks in underwater robotics. Such
coupled oscillators operate in clear and colloidal (mud, bottom silt) water and
represent a collective electrochemical sensor that is sensitive to global
environmental parameters, geometry of common electric field and spatial
dynamics of autonomous underwater vehicles (AUVs). Implemented in hardware and
software, this approach can be used to create global awareness in the group of
robots, which possess limited sensing and communication capabilities. Using
oscillators from different AUVs enables extending the range limitations related
to electric dipole of a single AUV. Applications of this technique are
demonstrated for detecting the number of AUVs, distances between them,
perception of dielectric objects, synchronization of behavior and
discrimination between 'collective self' and 'collective non-self' through an
'electrical mirror'. These approaches have been implemented in several research
projects with AUVs in fresh and salt water.
