NonlinearH∞Optimal Control Scheme for an Underwater Vehicle with Regional Function Formulation

A conventional region control technique cannot meet the demands for an accurate tracking performance in view of its inability to accommodate highly nonlinear system dynamics, imprecise hydrodynamic coefficients, and external disturbances. In this paper, a robust technique is presented for an Autonomous Underwater Vehicle (AUV) with region tracking function. Within this control scheme, nonlinearH∞and region based control schemes are used. A Lyapunov-like function is presented for stability analysis of the proposed control law. Numerical simulations are presented to demonstrate the performance of the proposed tracking control of the AUV. It is shown that the proposed control law is robust against parameter uncertainties, external disturbances, and nonlinearities and it leads to uniform ultimate boundedness of the region tracking error.

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Investigation into the Dynamics and Control of an Underwater Vehicle-Manipulator System

Modelling and Simulation in Engineering ◽

10.1155/2013/839046 ◽

2013 ◽

Vol 2013 ◽

pp. 1-13 ◽

Cited By ~ 9

Author(s):

Mohan Santhakumar

Keyword(s):

Autonomous Underwater Vehicle ◽

Underwater Vehicle ◽

Dynamic Coupling ◽

Parameter Uncertainties ◽

External Disturbances ◽

Model Reference Control ◽

Control Scheme ◽

Underwater Manipulator ◽

Dynamics And Control ◽

And Control

This study addresses the detailed modeling and simulation of the dynamic coupling between an underwater vehicle and manipulator system. The dynamic coupling effects due to damping, restoring, and inertial effects of an underwater manipulator mounted on an autonomous underwater vehicle (AUV) are analyzed by considering the actuator and sensor characteristics. A model reference control (MRC) scheme is proposed for the underwater vehicle-manipulator system (UVMS). The effectiveness of the proposed control scheme is demonstrated using numerical simulations along with comparative study between conventional proportional-integral-derivative (PID) control. The robustness of the proposed control scheme is also illustrated in the presence of external disturbances and parameter uncertainties.

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COMPARISON OF AN X4-AUV PERFORMANCE USING A BACKSTEPPING AND INTEGRAL BACKSTEPPING APPROACH

Jurnal Teknologi ◽

10.11113/jt.v78.9178 ◽

2016 ◽

Vol 78 (6-11) ◽

Author(s):

Nur Fadzillah Harun ◽

Zainah Md. Zain

Keyword(s):

Autonomous Underwater Vehicle ◽

Control Method ◽

Underwater Vehicle ◽

Control Technique ◽

Underactuated System ◽

Control Law ◽

Backstepping Approach ◽

Highly Nonlinear ◽

Backstepping Controller ◽

Propose Control System

X4-AUV is a type of an autonomous underwater vehicle (AUV) which has 4 inputs with six degrees of freedoms (6-DOFs) in motion and is classified under an underactuated system. Controlling an underactuated system is difficult tasks because of the highly nonlinear dynamic, uncertainties in hydrodynamics behaviour and mostly those systems fails to satisfy Brockett’s Theorem. It usually required nonlinear control technique and this paper proposed an integral backstepping controller for stabilizing an underactuated X4-AUV. A control law is designed for the system in new state space using integral backstepping. The performance of the proposed control method is examined through simulation and results demonstrate all motion is stabilized and convergence into desired point. We also compared the results with backstepping approach to see the effectiveness of the propose control system.

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H ∞ Based Adaptive Fuzzy Control of a Tower Crane System

Volume 4: Dynamics, Control and Uncertainty, Parts A and B ◽

10.1115/imece2012-86092 ◽

2012 ◽

Author(s):

Mansour Karkoub ◽

Tzu Sung Wu ◽

Chien Ting Chen

Keyword(s):

Fuzzy Control ◽

Time Delays ◽

Adaptive Fuzzy Control ◽

Tracking Performance ◽

Control Technique ◽

Control Law ◽

External Disturbances ◽

Adaptive Fuzzy ◽

Tower Crane ◽

Highly Nonlinear

Tower cranes are very complex mechanical systems and have been the subject of research investigations for several decades. Research on tower cranes has focused on the development of dynamical models (linear and nonlinear) as well as control techniques to reduce the swaying of the payload. Inherently, the dynamical model of the tower crane is highly nonlinear and classified as under-actuated. The crane system has potentially six degrees of freedom but only three actuators. Also, the actuators are far from the payload which makes the system non-colocated. The dynamic model describing the motion of the payload from point to point is affected by uncertainties, time delays and external disturbances which may lead to inaccurate positioning, reduce safety and efficacy of the overall system. It is proposed here to use an H∞ based adaptive fuzzy control technique to control the swaying motion of a tower crane. This technique will overcome modeling inaccuracies, such as drag and friction losses, effect of time delayed disturbances, as well as parameter uncertainties. The proposed control law for payload positioning is based on indirect adaptive fuzzy control. A fuzzy model is used to approximate the dynamics of the tower crane; then, an indirect adaptive fuzzy scheme is developed for overriding the nonlinearities and time delays. The advantage of employing an adaptive fuzzy system is the use of linear analytical results instead of estimating nonlinear system functions with an online update law. The adaptive fuzzy scheme fuses a Variable Structure (VS) scheme to resolve the system uncertainties, and the external disturbances such that H∞ tracking performance is achieved. A control law is derived based on a Lyapunov criterion and the Riccati-inequality to compensate for the effect of the external disturbances on tracking error so that all states of the system are uniformly ultimately bounded (UUB). Therefore, the effect can be reduced to any prescribed level to achieve H∞ tracking performance. Simulations are presented here to illustrate the performance of the proposed control design.

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Adaptive output feedback integral sliding mode attitude tracking control of spacecraft without unwinding

Advances in Mechanical Engineering ◽

10.1177/1687814017710406 ◽

2017 ◽

Vol 9 (7) ◽

pp. 168781401771040 ◽

Cited By ~ 8

Author(s):

Anuchit Jitpattanakul ◽

Chutiphon Pukdeboon

Keyword(s):

Output Feedback ◽

Tracking Control ◽

Sliding Mode ◽

Control Technique ◽

Control Law ◽

Parameter Uncertainties ◽

External Disturbances ◽

Integral Sliding Mode ◽

Attitude Tracking ◽

Attitude Tracking Control

This article studies an output feedback attitude tracking control problem for rigid spacecraft in the presence of parameter uncertainties and external disturbances. First, an anti-unwinding attitude control law is designed using the integral sliding mode control technique to achieve accurate tracking responses and robustness against inertia uncertainties and external disturbances. Next, the derived control law is combined with a suitable tuning law to relax the knowledge about the bounds of uncertainties and disturbances. The stability results are rigorously proved using the Lyapunov stability theory. In addition, a new finite-time sliding mode observer is developed to estimate the first time derivative of attitude. A new adaptive output feedback attitude controller is designed based on the estimated results, and angular velocity measurements are not required in the design process. A Lyapunov-based analysis is provided to demonstrate the uniformly ultimately bounded stability of the observer errors. Numerical simulations are given to illustrate the effectiveness of the proposed control method.

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An Adaptive Hierarchical Sliding Mode Controller for Autonomous Underwater Vehicles

Electronics ◽

10.3390/electronics10182316 ◽

2021 ◽

Vol 10 (18) ◽

pp. 2316

Author(s):

Quang Van Vu ◽

Tuan Anh Dinh ◽

Thien Van Nguyen ◽

Hoang Viet Tran ◽

Hai Xuan Le ◽

...

Keyword(s):

Adaptive Learning ◽

Autonomous Underwater Vehicle ◽

Sliding Mode ◽

Autonomous Underwater Vehicles ◽

Lyapunov Theory ◽

Control Technique ◽

External Disturbances ◽

Control Scheme ◽

Hierarchical Sliding Mode ◽

Over Time

The paper addresses a problem of efficiently controlling an autonomous underwater vehicle (AUV), where its typical underactuated model is considered. Due to critical uncertainties and nonlinearities in the system caused by unavoidable external disturbances such as ocean currents when it operates, it is paramount to robustly maintain motions of the vehicle over time as expected. Therefore, it is proposed to employ the hierarchical sliding mode control technique to design the closed-loop control scheme for the device. However, exactly determining parameters of the AUV control system is impractical since its nonlinearities and external disturbances can vary those parameters over time. Thus, it is proposed to exploit neural networks to develop an adaptive learning mechanism that allows the system to learn its parameters adaptively. More importantly, stability of the AUV system controlled by the proposed approach is theoretically proved to be guaranteed by the use of the Lyapunov theory. Effectiveness of the proposed control scheme was verified by the experiments implemented in a synthetic environment, where the obtained results are highly promising.

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Dynamic Neural Network-Based Adaptive Tracking Control for an Autonomous Underwater Vehicle Subject to Modeling and Parametric Uncertainties

Applied Sciences ◽

10.3390/app11062797 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2797

Author(s):

Filiberto Muñoz ◽

Jorge S. Cervantes-Rojas ◽

Jose M. Valdovinos ◽

Omar Sandre-Hernández ◽

Sergio Salazar ◽

...

Keyword(s):

Degrees Of Freedom ◽

Neural Control ◽

Autonomous Underwater Vehicle ◽

Parametric Uncertainty ◽

Underwater Vehicle ◽

Added Mass ◽

Parametric Estimation ◽

Parameter Uncertainties ◽

External Disturbances ◽

Adaptive Tracking Control

This research presents a way to improve the autonomous maneuvering capability of a four-degrees-of-freedom (4DOF) autonomous underwater vehicle (AUV) to perform trajectory tracking tasks in a disturbed underwater environment. This study considers four second-order input-affine nonlinear equations for the translational (x,y,z) and rotational (heading) dynamics of a real AUV subject to hydrodynamic parameter uncertainties (added mass and damping coefficients), unknown damping dynamics, and external disturbances. We proposed an identification-control scheme for each dynamic named Dynamic Neural Control System (DNCS) as a combination of an adaptive neural controller based on nonparametric identification of the effect of unknown dynamics and external disturbances, and on parametric estimation of the added mass dependent input gain. Several numerical simulations validate the satisfactory performance of the proposed DNCS tracking reference trajectories in comparison with a conventional feedback controller with no adaptive compensation. Some graphics showing dynamic approximation of the lumped disturbance as well as estimation of the parametric uncertainty are depicted, validating effective operation of the proposed DNCS when the system is almost completely unknown.

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Backstepping active disturbance rejection control for trajectory tracking of underactuated autonomous underwater vehicles with position error constraint

International Journal of Advanced Robotic Systems ◽

10.1177/1729881420909633 ◽

2020 ◽

Vol 17 (2) ◽

pp. 172988142090963

Author(s):

Tianqi Xie ◽

Ye Li ◽

Yanqing Jiang ◽

Li An ◽

Haowei Wu

Keyword(s):

Trajectory Tracking ◽

Disturbance Rejection ◽

Autonomous Underwater Vehicle ◽

Underwater Vehicle ◽

Time Varying ◽

Active Disturbance Rejection Control ◽

Parameter Uncertainties ◽

External Disturbances ◽

Active Disturbance Rejection ◽

Disturbance Rejection Control

In this article, the three-dimensional trajectory tracking control of an autonomous underwater vehicle is addressed. The vehicle is assumed to be underactuated and the system parameters and the external disturbances are unknown. First, the five degrees of freedom kinematics and dynamics model of underactuated autonomous underwater vehicle are acquired. Following this, reduced-order linear extended state observers are designed to estimate and compensate for the uncertainties that exist in the model and the external disturbances. A backstepping active disturbance rejection control method is designed with the help of a time-varying barrier Lyapunov function to constrain the position tracking error. Furthermore, the controller system can be proved to be stable by employing the Lyapunov stability theory. Finally, the simulation and comparative analyses demonstrate the usefulness and robustness of the proposed controller in the presence of internal parameter uncertainties and external time-varying disturbances.

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Path Following Control of Fully Actuated Autonomous Underwater Vehicle Based on LADRC

Polish Maritime Research ◽

10.2478/pomr-2018-0130 ◽

2018 ◽

Vol 25 (4) ◽

pp. 39-48 ◽

Cited By ~ 3

Author(s):

Habib Choukri Lamraoui ◽

Zhu Qidan

Keyword(s):

Real Time ◽

Tracking Control ◽

Autonomous Underwater Vehicle ◽

Path Following ◽

Underwater Vehicle ◽

Control Law ◽

External Disturbances ◽

Path Following Control ◽

State Measurement ◽

Full State

Abstract This paper presents an active disturbances rejecter controller (ADRC) for position and path following control of a fully actuated autonomous underwater vehicle (AUV). The unmodeled, undesirable dynamics and disturbances reduce the performances of classical controllers and complicate the design of appropriate and efficient controllers. In the proposed approach, the different modeling complexities; such as uncertain parameters, non-linearities, and external disturbances are considered all as a part of disturbance which is estimated in real-time by the extended state observer ESO, and effectively compensated from the control law. The ESO is also able to estimate the position and velocity of the system in real-time, in case where the full state measurement of the AUV is not possible during experiments. Computer simulations demonstrate the high ability of the AUV tracking control based on ADRC, to follow the desired trajectory in the horizontal plane and space with high precision, and showed high robustness and efficiency in rejecting the external and internal disturbances caused by significant changes in parameters of the system, and the added position disturbances.

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