Hung Nguyen

• Australian Maritime College

Computational Fluid Dynamics (CFD) simulations using Reynolds Averaged Navier-Stokes (RANS) equations are increasingly adopted as an analysis tool to predict the hydrodynamic coefficients of underwater vehicles. These simulations have shown to offer both a high degree of accuracy comparable to experimental methods and a greatly reduced computationa...

When an Autonomous Underwater Vehicle (AUV) is operating close to a moving submarine, the hydrodynamic interaction between the two vehicles can prevent the AUV from maintaining its desired trajectory. This can lead to mission failure and, in extreme cases, collision with the submarine. This paper outlines the transient interaction influence on the...

Command governor–based adaptive control (CGAC) is a recent control strategy that has been explored as a possible candidate for the challenging task of precise maneuvering of unmanned underwater vehicles (UUVs) with parameter variations. CGAC is derived from standard model reference adaptive control (MRAC) by adding a command governor that guarantee...

Non-parametric system identification with Gaussian processes for underwater vehicles is explored in this research with the purpose of modelling autonomous underwater vehicle (AUV) dynamics with a low amount of data. Multi-output Gaussian processes and their aptitude for modelling the dynamic system of an underactuated AUV without losing the relatio...

System modelling of the surface ship, which could be regarded as a multi-variable parameter estimation problem, has attracted tremendous interests from researchers since it is of key importance to development of ships’ control system. The aim of this study is to utilize the Particle Swarm Optimization (PSO) algorithm to get the optimized solution o...

The collective and cyclic pitch propeller (CCPP) is a novel concept designed to propel and manoeuvre autonomous underwater vehicles (AUVs). Collective pitch control governs the generated thrust, while through cyclic pitch control a manoeuvring force/side-force is generated. Recent work concluded that new solutions are needed to achieve large side-f...

An array of pressure sensors can be used to correct the drift in inertial navigation systems for underwater vehicles (UVs) in absence of other navigation support systems such as acoustic positioning, GPS and Doppler velocity measurements. To date, multiple pressure sensor arrays have been designed, proposed, and tested to prove the concept. However...

We introduce an adaptive sampling method that has been developed to support the Backseat Driver control architecture of the Memorial University of Newfoundland (MUN) Explorer autonomous underwater vehicle (AUV). The design is based on an acoustic detection and in-situ analysis program that allows an AUV to perform automatic detection and autonomous...

Underwater vehicles are employed in the exploration of dynamic environments where tuning of a specific controller for each task would be time-consuming and unreliable as the controller depends on calculated mathematical coefficients in idealised conditions. For such a case, learning task from experience can be a useful alternative. This paper explo...

Non-parametric system identification with Gaussian Processes for underwater vehicles is explored in this research with the purpose of modelling autonomous underwater vehicle (AUV) dynamics with low amount of data. Multi-output Gaussian processes and its aptitude to model the dynamic system of an underactuated AUV without losing the relationships be...

Challenging frequency control issues, such as the reliability and security of the power system, arise when increasing penetration levels of inverter-interfaced generation are imposed. As a result of the displacement of convention generation in favour of renewable energy sources, the reduction of frequency response capabilities can be seen. A promis...

Due to the nonlinearity and environmental uncertainties, the design of the ship's steering controller is a long-term challenge. The purpose of this study is to design an intelligent autopilot based on Extended Kalman Filter (EKF) trained Radial Basis Function Neural Network (RBFNN) control algorithm. The newly developed free running model scaled su...

We have developed an adaptive sampling algorithm for an Explorer autonomous underwater vehicle (AUV) to conduct in-situ analysis of acoustic measurements to perform autonomous oil plume detection and tracking. The methodology of the tracking phase involves ongoing analysis of the detected plume, assessing target validity and proximity for AUV decis...

Underwater vehicles are employed in the exploration of dynamic environments where tuning of a specific controller for each task would be time-consuming and unreliable as the controller depends on calculated mathematical coefficients in idealised conditions. For such a case, learning task from experience can be a useful alternative. This paper explo...

The roll motions of ships advancing in heavy seas have severe impacts on the safety of crews, vessels, and cargoes; thus, it must be damped. This study presents the design of a rudder roll damping autopilot by utilizing the dual extended Kalman filter (DEKF)–trained radial basis function neural networks (RBFNN) for the surface vessels. The autopilo...

This paper explores the use of Gaussian Process based unscented Kalman filter Algorithm (GP-UKF) for position estimation of underwater vehicles. GP-UKF has number of advantages over parametric UKFs and Bayesian filters such as improved tracking quality and graceful degradation with the increase of model uncertainty. The advantage of GP over paramet...

A novel propulsion and manoeuvring system for Autonomous Underwater Vehicles (AUVs), the collective and cyclic pitch propeller (CCPP), has been the focus of recent (numerical) research efforts. The CCPP offers advanced control of the blade pitch to provide effective and efficient propulsion and manoeuvring forces at both highand low forward velocit...

Unmanned Underwater Vehicles (UUVs) are increasingly being used in advanced applications that require them to operate in tandem with human divers and around underwater infrastructure and other vehicles. These applications require precise control of the UUVs which is challenging due to the non-linear and time varying nature of the hydrodynamic force...

Estimation and analysis of the uncertainty introduced by using a numerical model for the investigation and study of any type of flow problem have become common industry practice. Through understanding and evaluation of the uncertainty introduced by a numerical model, the accuracy and applicability of the model itself are evaluated. In this paper, t...

In the recent decades, the application and research of unmanned surface vessels are experiencing considerable growth, which have caused the demands of intelligent autopilots to grow along with the ever-growing requirements. In this study, the design of an autopilot based on Unscented Kalman Filter (UKF) trained Radial Basis Function Neural Networks...

Propulsion and maneuvering of autonomous underwater vehicles require a combination of effective and efficient operation at both high and low speeds. The collective and cyclic pitch propeller (CCPP) is a novel system designed to provide the required operational flexibility through control of the propeller’s blade pitch. Collective pitch control gove...

The global shipping fleet is vital to world trade with billions of tonnes of cargo being transported annually by merchant vessels. This activity however results in large volumes of carbon emissions and airborne particulate matter being released into the atmosphere due to the burning of fossil fuels for propulsion and on-board power. Recently, there...

A series of experimental studies of the innovative propulsor named Collective and Cyclic Pitch Propeller (CCPP) applied to an underwater vehicle were designed and performed at the Australian Maritime College, University of Tasmania. The bollard pull and captive model tests were conducted to investigate the characteristics of CCPP and to examine the...

This paper investigates the impact of adding tidal energy on the size of battery energy storage (BES) required to absorb power fluctuations present in a standalone microgrid with wind, solar and diesel engine is driven generation sources. The Flinders Island power system is chosen as the standalone microgrid for the case study. In addition to the b...

In the rapid growing of the green energy technology, microgrid systems with renewable energy sources (RESs) such as solar, wind and fuel cells are becoming a prevalent and efficient way to control and manage these renewable sources. Moreover, owing to the intermittency and the frequent irregular responses of the RESs, battery energy storages have b...

In today's underwater environment, complex missions, such as underwater repair and docking operations, require precise control to maneuver unmanned underwater vehicles (UUVs) in extremely demanding operating conditions. Although numerous control methodologies have been used for UUVs, adaptive control is considered a promising solution due to its in...

Microgrids are increasingly being used as a platform to integrate distributed generation such as renewable energy sources and (RESs) conventional sources in both grid-connected and isolated power systems. Due to the inherent intermittent nature of RESs, energy storage systems (ESSs) that can absorb fluctuations have become inevitable. Nevertheless,...

A novel application of non-parametric system identification algorithm for a surface ship has been employ on this study with the aim of modelling ships dynamics with low quantity of data. The algorithm is based on multi-output Gaussian processes and its ability to model the dynamic system of a ship without losing the relationships between coupled ou...

In the revolution of green energy development, microgrids with renewable energy sources such as solar, wind and fuel cells are becoming a popular and effective way of controlling and managing these sources. On the other hand, owing to the intermittency and wide range of dynamic responses of renewable energy sources, battery energy-storage systems h...

Autonomous Underwater Vehicle (AUV) is a growing technology with a great potential to both military and civilian applications. Extensive developments and advanced innovations of AUV have been introduced in recent years from various research centres around the world. Among the fundamental modules of an AUV, the propulsion system strongly affects the...

This article presents the open water propeller characteristics and the four-quadrant propeller models as applied to a torpedo-shaped underwater vehicle. A series of experiments with a Gavia autonomous underwater vehicle propeller were conducted in the towing tank using a rotor testing apparatus. The purpose of these tests was to measure the propell...

The control of unmanned underwater vehicles (UUV) is a complex problem mainly due to the nonlinear dynamics, uncertainty in model parameters, and external disturbances. Adaptive control is a promising solution to address these issues. Nevertheless, its full potential is yet to be realized, especially in underwater vehicle applications, mainly due t...

The large roll motion of ships sailing in the seaway is undesirable because it may lead to the seasickness of crew and unsafety of vessels and cargoes, thus it needs to be reduced. The aim of this study is to design a rudder roll stabilization system based on Radial Basis Function Neural Network (RBFNN) control algorithm for ship advancing in the s...

In recent years, the problem of rogue waves has been a topical issue among oceanographers because of their dangerous and unpredictable properties, leading to safety demands for ships and offshore platforms. Even with efforts to physically quantify the mechanism of rogue wave generation within the last two decades, rogue wave events are still unpred...

The collective and cyclic pitch propeller (CCPP) is a propulsion and manoeuvring system for Autonomous Underwater Vehicles (AUVs). Through control of the pro-peller's blade pitch the CCPP is capable of generating propulsion and manoeuvring forces in an effective and efficient manner at both high and low speeds. Recent studies identified the need fo...

The collective and cyclic pitch propeller (CCPP) is a novel efficient and effective propulsion and manoeuvring alternative for Autonomous Underwater Vehicles (AUVs). A two-dimensional numerical model was developed to investigate the hydrodynamic performance of the CCPP, simplifying the three-dimensional CCPP’s blade operation to that of two-dimensi...

Approximately 12% of the world's oceans are covered by ice. Understanding the physical processes, ecosystem structure, mixing dynamics and the role of these inaccessible environments in the context of global climate change is extremely important. Autonomous Underwater Vehicles (AUVs) play a major role in the potential exploration of these water sys...

This article presents the development of a novel artificial potential field technique for a haptic controller of an underwater remotely operated vehicle to assist the pilot to avoid obstacles. The artificial potential field technique is used to replicate potential risks presented by underwater obstacles in the vicinity of the remotely operated vehi...

This paper presents the identification of mathematical models governing dynamics in both the vertical and horizontal planes for a axisymmetric, torpedo-shaped Gavia class Autonomous Underwater Vehicle (AUV), based on a least squares optimisation algorithm. Rather than using the least squares algorithm to roughly estimate the mathematical models in...

Unmanned Underwater Vehicles (UUVs) are being deployed in advanced applications that require precise manoeuvring close to complex underwater structures such as oilrigs and subsea installations or moving objects such as submarines. The effect of vehicle hydrodynamic parameter variations is significant in such scenarios and in extreme conditions the...

This paper presents the development of a heading angle observer for Underwater Remotely Operated Vehicles (ROVs) during dynamic conditions in the presence of roll/pitch oscillation and acceleration disturbances. Unlike previous algorithms, which focused on deep water working environments where the external accelerations and oscillation were rather...

The control of unmanned underwater vehicles (UUVs) is challenging due to the non-linear and time-varying nature of the hydrodynamic forces from the surrounding fluid. In addition, the presence of external disturbances makes the control even more difficult. Model reference adaptive control (MRAC) is an adaptive control technique that performs well i...

When an Autonomous Underwater Vehicle (AUV) operates close to a submarine, interaction with the flow and pressure fields of the submarine can adversely affect the motion of the AUV. These interactions can result in uncontrollable motions of the AUV, which in extreme cases can lead to mission failure due to collision with the submarine or the inabil...

This paper presents the design and simulation of a command governor based adaptive controller (CGAC) for a remotely operated underwater vehicle. The command governor modification is applied for the first time to an underwater vehicle simulation of the actual vehicle for improved transient performance and disturbance rejection. The vehicle dynamics...

This paper presents the development of a haptic driving system for underwater Remotely Operated Vehicles (ROVs). Unlike conventional ROV driving systems, which only transmit commands from the pilots to the vehicle controller, the proposed haptic device has the ability to provide information about the working environment back to the operator via tac...

This paper presents the development of a low cost Remotely Operated Vehicle (ROV) which consists of open source hardware and has three thrusters. First, the hardware of the vehicle, including the actuators, sensors, and control structure, is described. Second, to study the relationship between the thrust forces and the performance of the ROV, a mat...

Computational Fluid Dynamics (CFD) simulations using Reynolds Averaged Navier-Stokes (RANS) equations are increasingly adopted as an analysis tool to predict the hydrodynamic coefficients of underwater vehicles. These simulations have shown to offer both a high degree of accuracy comparable to experimental methods and a greatly reduced computationa...

When an Autonomous Underwater Vehicle (AUV) is operating close to a moving submarine, the hydrodynamic interaction between the two vehicles can prevent the AUV from maintaining its desired trajectory. This can lead to mission failure and, in extreme cases, collision with the submarine. This paper outlines the transient interaction influence on the...

Increasing fuel costs and regulation of emissions are encouraging operators, shipbuilders and researchers to seek improvements in marine vessel efficiency. In the area of vessel electrical systems, there are increasing choices as a result of research and development over the past decade giving rise to a number of promising new technologies. Promisi...

Continuing the previously published study [4], this paper focuses on hardware and Virtual Reality (VR) model development of a three-thruster Remotely Operated Vehicle (ROV). The paper included setting up an on-board electronic system with the associated suite of sensors and the required communication protocol. This system utilizes a master-slave st...

The hydrodynamic interaction effects on an Unmanned Underwater Vehicle (UUV) operating in close proximity to a moving submarine can adversely affect the safety and handling of the former. This paper outlines the steady-state interaction forces and moments acting on an UUV at relative longitudinal locations along the submarine, as well as varying th...

This paper presents modelling and simulation of an underwater vehicle equipped with a collective and cyclic propeller (CCPP). A CCPP has been applied in helicopters and it generates both axial and side thrusts that move a helicopter in all directions. If axial and side thrusts of the CCPP are controlled as desired it is possible to apply the CCPP t...

An Autonomous Underwater Vehicle (AUV) operating closer to a larger vessel experiences significant hydrodynamic forces requiring an adaptive control mechanism to maintain acceptable trajectory. It is therefore important that the designer understands the hydrodynamic characteristics of the vehicle in this scenario in order to develop appropriate con...

This paper presents a new approach to design a multitask automatic manoeuvring system by using recursive identification and optimal control algorithms. The shippsilas manoeuvring dynamics is described by an appropriate multivariable auto-regressive exogenous (MARX) model with unknown parameters. A recursive estimation algorithm is applied to estima...

This article presents new applications of recursive identification methods to estimation of ship manoeuvring dynamics and hydrody-namics. A vessel operated in sea water can be represented by a mathe-matical model with unknown coefficients called ship manoeuvring dy-namic coefficients or hydrodynamic coefficients. Computer simulation and full scale...

The ideas of developing recursive optimal manoeuvring systems are based on the author's recent research results related to applications of the recursive estimation procedures and modern control theory in marine control systems. The manoeuvring is a trajectory tracking control system. The adopted method is combination of a recursive estimation proce...