Title: High-gain-observer based adaptive output-feedback formation control for underactuated unmanned surface vessels with input saturation and uncertainties

Authors: Meijiao Zhao; Huayan Pu; Yueying Wang; Jun Luo; Shaorong Xie; Yan Peng

Addresses: School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, 200444, China ' School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, 200444, China ' School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, 200444, China ' School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, 200444, China ' School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, 200444, China ' School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, 200444, China

Abstract: An adaptive output feedback formation control strategy based on high gain observer has been developed to solve the problem of underactuated surface vessels formation control with uncertain dynamics, ocean environment disturbance and input saturation. In this strategy, a high gain observer that only depends on position information is used to estimate the unmeasurable velocity, and in order to solve the ‘complex explosion problem’ in the conventional backstepping control algorithm, a first-order low-pass filter is adopted to obtain the derivative of the virtual control signal. In addition, adaptive neural networks (NNs) and minimum learning parameters (MLPs) algorithm are used to approximate environmental disturbances and uncertain dynamics, while reducing online update parameters. Stability analysis proved that all signals in closed-loop are uniformly ultimately bounded and the formation tracking errors are arbitrarily small. Simulation results demonstrate the effectiveness of the controller.

Keywords: output feedback; adaptive; backstepping; neural networks; formation control; high gain observer; underactuated surface vessels; input saturation; uncertainty.

DOI: 10.1504/IJVD.2020.115852

International Journal of Vehicle Design, 2020 Vol.84 No.1/2/3/4, pp.180 - 202

Received: 31 Dec 2019
Accepted: 23 Jun 2020

Published online: 25 Jun 2021 *

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