Cooperative Manipulation on the Water Using a Swarm of Autonomous Tugboats

Abstract

In this paper we present a strategy that allows a swarm of autonomous tugboats to cooperatively move a large object on the water. The two main challenges are: (1) the actuators are unidirectional and experience saturation; (2) the hydrodynamics of the system are difficult to characterize. The primary theoretical contribution of the paper addresses the first challenge. We present a tracking controller and force allocation strategy that, despite actuator limitations, result in asymptotically convergent tracking for a certain class of reference trajectories. The primary practical contribution is the introduction of a set of adaptive control laws that address the second challenge by compensating for unknown, and difficult to measure, hydrodynamic parameters. Experimental verification of the controllers is presented using a 1:36 scale model of a U.S. Navy ship, inside the Naval Academy's unique 380 ft testing tank.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 2008
Accession Number
ADA535042

Entities

People

  • Erik Smith
  • Joel Esposito
  • M. Feemster

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Actuators
  • Coefficients
  • Drag
  • Dynamics
  • Engineering
  • Mechanical Equipment
  • Models
  • Naval Architecture
  • Offshore Structures
  • Optimization
  • Orientation (Direction)
  • Robots
  • Simulations
  • Systems Engineering
  • Test Beds
  • Trajectories
  • United States Naval Academy

Readers

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  • Marine Hydrodynamics