Strategies for simultaneous multiple autonomous underwater vehicle operation and control

Abstract

Undersampling of the coastal oceans remains a persistent problem for standard oceanographic measurement practice wherein an instrument package is tethered to a research vessel. The overhead costs associated with operating a large research vessel impose a strict minimum on the cost of data collected. Owing to the overheads, significant improvements in sampling technology on the tethered platform can only produce modest gains in the cost effectiveness. In contrast. untethered vehicles if operated simultaneously have the potential to increase cost effectiveness significantly by distributing the overhead costs over several sampling platforms. Furthermore, synoptic and pseudosynoptic data can be collected with multiple autonomous underwater vehicles (A UVs). thereby providing the type of information critical to dynamic process modeling unattainable with non-synoptic data. While the goal of simultaneous multiple-vehicle operation has been espoused over the last few years. A UV technology and practice have until recently been too immature to realize that potential. Recently, Florida Atlantic University (FA U) has developed a new series of modular A UVs with the express purpose of supporting multiple sensors and multiple-vehicle operation. This series of vehicle is called the Ocean Explorer of which three have been produced so far. This paper will explore some of the associated navigation, tracking, control and deployment problems associated with multiple-vehicle operation in coastal applications. In addition, the characteristics of the component level intelligent distributed control system. integrated data logger and vehicle control system will be discussed. In particular this paper will discuss how FA U has applied the concepts ofelastic constraint propagation and the symmetric fuzzy decision-making model /0 A UV control systems. Some results of early experiments ill synoptic data collection with a conductivity, temperature and depth (CTD) sensor using multiple A UVs for the determination of horizontal structure will be described.

A two-level, protocol-based approach to controlling autonomous oceanographic sampling networks

“…This allows any changes in the composition of the AOSN since deployment (or last re-formation) 00:16:40.0 (SIM) ******************************** 00:16:40.0 (SIM) **Event: (agent-exit mooring-Epsilon). 00:16:40.0 (SIM) ******************************** 00: 16 to be taken into account. In future work, we will investigate the benefits of allowing the MLO to remain active in some form while the TLO is working.…”

Command, control, and navigation experimental results with the NPS ARIES AUV

“…The use of AUVs for Ocean Survey and military mine countermeasures is well documented, [1], [2], and [3] among many others. The continuing problems facing further commercial use of such systems include accurate underwater navigation and communications links.…”

Enhancement of the inertial navigation system for the Morpheus autonomous underwater vehicles

“…To further capitalize on this output, operations that involve a fleet of small (communicative) AUVs become financially possible [23].…”

“…In addition, the performance of this externally aided positioning depends largely on the sound-speed profile in the water column. For multiple AUV operations, independent sets of beacons must be installed, and this rapidly increases the logistical complexity of a mission [23].…”