Hardware architecture for a modular autonomous underwater vehicle STARFISH

Abstract

The use of Autonomous Underwater Vehicles (AUVs) in various research, commercial and military applications has significantly increased in the recent years. Most AUVs available commercially tend to be complex and very expensive. With advances in recent technology, sensors with new functionality or lower cost substitutes have become available. Most existing AUV platforms do not facilitate easy integration of new or upgraded sensors. A solution to this problem is to have a modular AUV system with changeable payload sections capable of carrying different sensor to suite different missions. Modular AUVs are exceptionally useful in group mission scenarios with different AUVs carrying different sensor payloads. By having a team of modular AUVs, payloads can be easily interchanged between the AUVs to configure the team for various missions. Modular AUVs require their sections to be electrically and mechanically compatible with one another. At the Acoustic Research Laboratory (ARL) of the National University of Singapore (NUS) we have built one such modular open-architecture AUV called STARFISH. It has both software as well as hardware modularity. The hardware architecture for STARFISH has been designed to achieve a common electrical and mechanical interface between the different sections thus providing a plug and play capability between them. A general electrical architecture has been defined for all AUV sections in order to achieve electrical modularity. Employing this general architecture, individual sections have been tailored according to their functionality. The architecture has been implemented by using a combination of micro-controllers and single board computers which communicate over Ethernet. A distributed power architecture has been defined to allow AUV sections to contain power sources. STARFISH has a power management unit which manages the power distribution, charges batteries and provides emergency power cut offs. By using Ethernet and a common power bus system a common electrical interface between the AUV sections can be achieved. STARFISH also has advanced emergency safety systems consisting of leak sensors, emergency micro-controller capable of operating a GPS/GSM device, a pinger and a strobe. In this paper we describe the detailed architecture of the electronics system for STARFISH AUV. The benefits of modular hardware and its advantages in developing and integrating newer sensor payloads with the base AUV are shown. The modular electronics system for STARFISH AUV has been implemented and currently being tested. © 2008 IEEE.