Model-Based Control and Stability Analysis of Underactuated Autonomous Underwater Vehicles Via Singular Perturbations

2020 ◽  
Vol 15 (6) ◽  
Author(s):  
Ming Lei ◽  
Ye Li
Keyword(s):  
Stability Analysis ◽  
Time Scale ◽  
Control Strategies ◽  
Autonomous Underwater Vehicles ◽  
Path Following ◽  
Underwater Vehicles ◽  
Time Scale Separation ◽  
Independent Analysis ◽  
Effective Performance ◽  
Analysis Of Dynamics

Abstract This paper presents the control design and stability analysis for path-following of underactuated autonomous underwater vehicles (AUVs), with dynamics restricted to the horizontal plane. As illustration, the time-scale separation caused by different rates of numerous variables is exploited via a singular perturbation model formulation. On the basis of that, a time-scale decomposition method is used to decompose the full system into three-time scale subsystems. The three-time scale structure allows independent analysis of dynamics in each time scale. Therefore, control strategies are designed in each subsystem separately, leading to a reduction of control complexity and a relatively simple control law. This paper also demonstrates the asymptotic stability of the closed-loop system with a composite Lyapunov function candidate and provides alternative, simple but generic mathematical bounds on the singularly perturbed parameters. Finally, the simulation results are presented to illustrate the effective performance of proposed controller.

scholarly journals Output-Feedback Control for Path Following of Autonomous Underwater Vehicles via Singular Perturbation Technique

2021 ◽  
Author(s):  
Ming Lei ◽  
Ye Li ◽  
Shuo Pang
Keyword(s):  
Singular Perturbation ◽  
Output Feedback ◽  
Time Scale ◽  
Decomposition Method ◽  
Autonomous Underwater Vehicles ◽  
Path Following ◽  
Underwater Vehicles ◽  
Design Parameters ◽  
External Disturbances ◽  
Time Scale Decomposition

Abstract Autonomous underwater vehicles are needed in many applications such as underwater monitoring and surveillance, marine biology, rescue and search, undersea oil detection. In reality, the unknown external disturbances, and model uncertainties make the motion control of autonomous underwater vehicles a challenging task. With these issues, this paper presents an output-feedback singular perturbation control scheme for the path following of autonomous underwater vehicles, in term of the time scale decomposition method. As illustration, an extended state observer is first devised based on the singular perturbation theory. Then the stabilizing controller is developed by using the time scale decomposition method, in order to obtain a simple, easy-to-implement control law. And the stability analysis of stabilizing control system is conducted by constructing a composite Lyapunov function, which allows to provide mathematical bounds on the design parameters. Finally, simulation results are presented to prove the efficacy of the proposed controller for path following of autonomous underwater vehicles subject to internal and external disturbances.

Path Following of Underactuated Marine Underwater Vehicles in the Presence of Unknown Ocean Currents

2014 ◽  
Author(s):  
Signe Moe ◽  
Walter Caharija ◽  
Kristin Y. Pettersen ◽  
Ingrid Schjølberg
Keyword(s):  
Oil And Gas ◽  
Autonomous Underwater Vehicle ◽  
Autonomous Underwater Vehicles ◽  
Path Following ◽  
Oil And Gas Industry ◽  
Underwater Vehicle ◽  
Underwater Vehicles ◽  
Ocean Currents ◽  
The Arctic ◽  
Ocean Current

The use of autonomous marine vehicles, and especially autonomous underwater vehicles, is rapidly increasing within several fields of study. In particular, such vehicles can be applied for sea floor mapping, oceanography, environmental monitoring, inspection and maintenance of underwater structures (for instance within the oil and gas industry) and military purposes. They are also highly suitable for operations below ice-covered areas in the Arctic. However, there are still many challenges related to making such underwater vehicles autonomous. A fundamental task of an autonomous underwater vehicle vessel is to follow a general path in the presence of unknown ocean currents. There exist several results for underwater vehicles to follow a general path when no ocean currents are present [1] and to follow a geometrically simple path such as a straight line when ocean currents affect the vehicle [2, 3], but the problem of general path following in the presence of unknown ocean currents has not been solved yet. This paper presents a method to achieve this. The results are an extension of the results in [1], and introduce a virtual Serret-Frenet reference frame that is anchored in and propagates along the desired path. The closed-loop system consists of an ocean current observer, a guidance law, a controller and an update law to drive the Serret-Frenet frame along the path, and is shown to be asymptotically stable given that certain assumptions are fulfilled. This guarantees that the autonomous underwater vehicle will converge to the desired path and move along it with the desired velocity. Simulation results are presented to verify and illustrate the theoretical results.

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