Observer based output feedback tracking control of dynamically positioned surface vessels

Abstract

Abstract-This work concentrates on tracking control of dynamically positioned surface vessels where only position and orientation measurements are available. Specifically, in order to remove the velocity measurement dependency of the control formulation, we designed a nonlinear, model-free observer which enables the observer-controller couple to achieve asymptotic tracking. Stability of the closed-loop system is ensured by Lyapunov-based arguments. Simulation studies are also presented to illustrate the effectiveness of the proposed method.

Robust control synthesis for dynamic vessel positioning

“…In practice, some trade-offs should be made if a system designer aims to obtain the design objectives at the desired frequencies using sensitivity functions given in equations (8) and (9). For example, the disturbance and noise rejection cannot be achieved in the same frequency range.…”

“…where this LFT interconnection is well-posed if (I À P 33 K) is invertible. As described in equations (11) and (12), the matrix F l (P, K) = M can be expressed by various combinations of (weighted) sensitivity functions defined in equations (8) and (9). In addition, the closed-loop system via upper LFT is given by the transfer function from w to z, that is…”

“…The LQG with observer provides useful techniques for designing DP controller. 9 Here, the observer is needed to reconstruct the LF motions from the position and heading measurements. However, the optimal controls with Kalman filtering have fundamental problems in which modeling errors and uncertainties are not explicitly taken into account.…”

Observer-based adaptive output feedback tracking control of dynamically positioned surface vessels

“…The proposed controller achieved semi-global exponential stability provided the exact knowledge of the system parameters. Recently, in [4], we utilized an exact model knowledge observer-controller couple for tracking control of dynamically positioned surface vessels where only position and orientation measurements were available. A nonlinear model-free observer was designed to remove the velocity dependency of the control formulation.…”

A robust tracking controller for dynamically positioned surface vessels with added mass

“…In [9], a class of nonlinear proportional derivative control laws for position regulation were developed without guaranteeing their robustness against parametric uncertainties, and in [11], a robust nonlinear control law using singular perturbation theory that takes parametric uncertainties and external disturbances into account was presented. Some other past research has focused on designing output feedback control algorithms [7], [8], [13], [14]. In [7], a nonlinear output feedback controller utilizing an observer backstepping method was designed.…”