Sonar aided navigation and control of small UUVs

This paper addresses the problem of guiding a simple unmanned underwater vehicle (UUV) from a more capable, sonar equipped, platform, preferably an autonomous underwater or surface vessel (AxV). One application of this concept, considered in this article, is autonomous mine neutralization and disposal. First, a sonar equipped AxV acquires a possible target in the sonar image. Once the target location is known, an expendable UUV is released. The UUV position is determined from sonar imagery onboard the AxV. This minimal information is sent to the UUV via acoustic link so that it can converge towards the desired target. With this approach, complex and expensive sensors are removed from the expendable vehicle, which now becomes a simple actuation system that carries the neutralization payload, and this in turn greatly increases cost efficiency. Although we review the concept in the domain of mine countermeasures (MCM) it is applicable to other problems where navigation aiding between platforms is beneficial. This paper focuses on preliminary results obtained in numerous pool and field experiments during different phases of system development.