A novel approach to 6-DOF adaptive trajectory tracking control of an AUV in the presence of parameter uncertainties

F. Rezazadegan*, K. Shojaei, F. Sheikholeslam, A. Chatraei

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

68 Citations (Scopus)


In this paper, the trajectory tracking control of an autonomous underwater vehicle (AUVs) in six-degrees-of-freedom (6-DOFs) is addressed. It is assumed that the system parameters are unknown and the vehicle is underactuated. An adaptive controller is proposed, based on Lyapunov's direct method and the back-stepping technique, which interestingly guarantees robustness against parameter uncertainties. The desired trajectory can be any sufficiently smooth bounded curve parameterized by time even if consist of straight line. In contrast with the majority of research in this field, the likelihood of actuators' saturation is considered and another adaptive controller is designed to overcome this problem, in which control signals are bounded using saturation functions. The nonlinear adaptive control scheme yields asymptotic convergence of the vehicle to the reference trajectory, in the presence of parametric uncertainties. The stability of the presented control laws is proved in the sense of Lyapunov theory and Barbalat's lemma. Efficiency of presented controller using saturation functions is verified through comparing numerical simulations of both controllers.

Original languageEnglish
Pages (from-to)246-258
Number of pages13
JournalOcean Engineering
Publication statusPublished - 1 Oct 2015
Externally publishedYes


  • Adaptive controller
  • Autonomous underwater vehicle
  • Barbalat's lemma
  • Lyapunov theory
  • Saturation functions

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