Robust adaptive control of underactuated ships on a linear course with comfort

K. D. Do, J. Pan, Z. P. Jiang

Research output: Contribution to journalArticlepeer-review


This paper addresses an important problem in ship control application-the robust stabilization of underactuated ships on a linear course with comfort. Specifically, we develop a multivariable controller to stabilize ocean surface ships without a sway actuator on a linear course and to reduce roll and pitch simultaneously. The controller adapts to unknown parameters of the ship and constant environmental disturbances induced by wave, ocean current and wind. It is also robust to time-varying environmental disturbances, time-varying change in ship parameters and other motions of the ship such as surge and heave. The roll and pitch can be made arbitrarily small while the heading angle and sway are kept to be in reasonably small bounds. The controller development is based on Lyapunov's direct method and backstepping technique. A Lipschitz continuous projection algorithm is used to update the estimate of the unknown parameters to avoid the parameters' drift due to time-varying environmental disturbances. Simulations on a full-scale catamaran illustrate the effectiveness of our proposed controller.

Original languageEnglish (US)
Pages (from-to)2201-2225
Number of pages25
JournalOcean Engineering
Issue number17
StatePublished - Dec 2003


  • Linear course tracking
  • Pitch
  • Robust adaptive control
  • Roll
  • Underactuated ships

ASJC Scopus subject areas

  • Environmental Engineering
  • Ocean Engineering


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