Search

This paper proposes to investigate the performance of a path planning controller for a search-classify mission using multiple cooperative underwater vehicles. We present a control strategy for multi-agent cooperative systems, namely the Grid-based Multi-Objective Optimal Problem (GMOOP) solving technique, to find the optimal solutions for a search-classify mission using an action determination map subject to certain constraints and objectives. This technique is based on an Interval Programming (IvP) algorithm introduced in for representing and optimizing over multiple competing objective functions. We made improvements in this GMOOP technique to suit the harsh underwater acoustic communication environment by taking advantages of the Location-Aware Source Routing (LASR) protocol for underwater Mobile Ad hoc Network (MANET). Preliminary simulation trials based on two simplified scenarios have been carried out. Results show that the demanded cooperative search task could be finished satisfactorily under harsh acoustic constraints, and the performance of the GMOOP model are studied in various aspects.

A new generation of high-speed, high-frequency acoustic modem, named HERMES, has been developed. The acoustic communications link consists of a topside component and an underwater (wet-side) component. Together these components implement two underwater acoustic communication channels: a very high bit rate broadband data uplink and a low bit rate command downlink. The experimental results, obtained with the high-speed high-frequency acoustic uplink, demonstrate the system's ability to transmit high-resolution, uncompressed acoustic images with sufficient quality for any practical purposes. At the fastest data rate (mode 5), HERMES can transmit an uncompressed, high-resolution 400000-bit sonar image in 4.6 seconds. The results presented in this paper demonstrate that these data can be transmitted at a range of 120 m.