Some Design Considerations for a Solar Powered AUV; Energy Management and its Impact on Operational Characteristics

The Autonomous Undersea Systems Institute (AUSI) is currently working on the development of a solar powered Autonomous Underwater Vehicle (AUV) in cooperation with the Institute of Marine Technology Problems of the Russian Academy of Sciences. This technology development program is investigating those technologies that will enable the use of solar energy to power autonomous vehicles. This paper will discuss some of the technologies under investigation. This will include discussion of solar module performance, energy transfer issues to include charge control device technology, and energy monitoring devices such as fuel gauges. It will also consider energy management strategies being developed. A Sampling System For The 21st Century Ocean environmental monitoring has gained increased importance as the effect of mankind's activities on the world’s oceans becomes apparent. There is world-wide concern by research organizations over the inability to collect sufficient data with which to better understand the dynamics of chemical, biological and physical characteristics and processes within the earth's lakes, seas and oceans. Issues such as physical and biological coupling, biogeochemical processes and cycles both natural and human induced, fisheries, and ecosystem modeling must be better understood. The concerns vary from the enormous size of the data and sampling requirements, to the reliability and affordability of the systems presently used to collect data. Spatial and temporal undersampling in the oceans is generally recognized as one of the more important problems associated with current sampling systems. Although more detailed monitoring of the ocean is necessary, current instrumentation does not provide sufficient capability to collect the required data from the ocean on a continuous basis. This paper considers some of the issues associated with the development and utilization of a solar powered autonomous sampling system. The work described in this paper focuses on some the energy management strategies associated with a solar powered AUV system to address the needs of ocean sampling in the 21st century. The results reported here are preliminary, but they help define the unique constraints to be considered in the design of a solar powered AUV. The results of this and other investigations [Jal,1997] over the past few months have allowed the establishment of a technology database focused on the technologies and components important to the future utilization of solar energy as an energy source for autonomous sampling platforms. Work is currently underway to simulate, fabricate and evaluate a solar powered AUV testbed prototype detailed in figure 2. In water testing and evaluation experiments are scheduled to begin at the end of 1997.