Yaseen Adnan Ahmed - Academia.edu (original) (raw)

Papers by Yaseen Adnan Ahmed

Energies, 2020

The purpose of this paper is to estimate the H-Darrieus wind turbine aerodynamic performance, aer... more The purpose of this paper is to estimate the H-Darrieus wind turbine aerodynamic performance, aerodynamic blade loads, and velocity profiles downstream behind the rotor. The wind turbine model is based on the rotor designed by McDonnell Aircraft Company. The model proposed here consists of three fixed straight blades; in the future, this model is planned to be developed with controlled blades. The study was conducted using the unsteady Reynolds averaged Navier–Stokes (URANS) approach with the k-ω shear stress transport (SST) turbulence model. The numerical two-dimensional model was verified using two other independent aerodynamic approaches: a vortex model and the extended version of the computational fluid dynamics (CFD) code FLOWer. All utilized numerical codes gave similar result of the instantaneous aerodynamic blade loads. In addition, steady-state calculations for the applied airfoils were also made using the same numerical model as for the vertical axis wind turbine (VAWT) to...

WMU Journal of Maritime Affairs

The use of maritime autonomous vessels for the inland waterway (IWW) transport can revolutionise ... more The use of maritime autonomous vessels for the inland waterway (IWW) transport can revolutionise the current logistics supply chain and enable the shifting of the cargo transportation from the less efficient road and rail transport modes. However, the lack of guidelines and requirements for the operation and testing of autonomous vessels must be addressed to enable autonomous operations. This study aims to identify the gaps of the prevailing regulatory, liability and insurance frameworks and propose viable recommendations for the operation and testing of the autonomous IWW vessels. The theoretical case study of a next-generation autonomous ship operating in European IWW along with the required key enabling technologies is considered. A systematic methodological approach is followed focusing on the existing, transition and next-generation stages for developing autonomous vessels. The existing stage deals with classifying the identified gaps considering the categories of high, moderat...

Lecture notes in electrical engineering, 2023

ASEAN Engineering Journal, Aug 31, 2022

Research and development on sustainable alternatives to fossil fuels have become a prime focus fo... more Research and development on sustainable alternatives to fossil fuels have become a prime focus for the last couple of decades. Hydrogen, one of Earth's most abundant elements, holds great potential as a sustainable energy carrier. However, as Hydrogen is lighter than air, it does not exist in pure form in the atmosphere and is often found in compounds, such as water. The abundance of seawater in this regard makes Hydrogen an almost inexhaustible source of energy. Nevertheless, sustainable ways of extracting Hydrogen from water, dealing with its high corrosiveness and significantly lower evaporation point, still pose research challenges. Therefore, this paper aims at providing a comprehensive analysis of sustainable Hydrogen generation by focussing on the application of electrolysis to recover Hydrogen from water rather than using common reforming techniques. Different parameters affecting the efficiency and the overall performance of the electrolyser process have also been discussed and possible solutions to tackle the problems are presented. Later, a case study has been conducted to demonstrate the sustainable alternative for hydrogen production for an alkaline electrolyser using solar energy. MATLAB Simulink platform is used in this regard. This paper concludes that at an irradiation level of 1000W/m2, a PV array with 57 parallel strings with four modules connected in series per string is sufficient to provide enough power for the electrolyser to produce Hydrogen.

ASEAN Engineering Journal

Over the past decades, the attenuation of axial vibration due to propeller excitation has long be... more Over the past decades, the attenuation of axial vibration due to propeller excitation has long been a complex problem due to the coupling dynamics of the propeller-shafting system. As axial vibration is often the cause of fatigue damage to the propulsion shaft components as well as the root cause to acoustical radiation along a hull of a ship, there has been continuous interest in understanding the complex dynamic characteristics of the coupled propeller-shaft system and the methods to suppress the axial vibration in the system. Therefore, several studies have been conducted to solve this vibration problem on the longitudinal axis of the marine propulsion shafting system. This paper aims to provide the theoretical foundations of this problem by reviewing the modelling techniques of this coupled dynamic problem and cover the vibration reduction strategies that are proposed by the cited studies.

Advanced Maritime Technologies and Applications, 2022

Agriculture, 2021

Assessment of possible changes in crops water stress due to climate alteration is essential for a... more Assessment of possible changes in crops water stress due to climate alteration is essential for agricultural planning, particularly in arid regions where water supply is the major challenge for agricultural development. This study aims to project climatic water availability (CWA) and crop water demand (CWD) to outline the possible future agricultural water stress of Iraq for different radiative concentration pathways (RCPs). The ensemble means of downscaled precipitation and temperature projections of the selected global climate models (GCMs) were used in a simple water balance model for this purpose. The modified Mann–Kendall (mMK) trend test was employed to estimate the tendency in CWA and the Wilcoxon rank test to evaluate CWD alteration in three future time horizons compared to the base period (1971–2000). The results revealed a decrease in CWA at a rate of up to −34/year during 2010–2099 for RCP8.5. The largest declination would be in summer (−29/year) and an insignificant decr...

Lecture Notes in Mechanical Engineering, 2019

The investigation on the strain value for flexural sandwich panel syntactic foam were also carrie... more The investigation on the strain value for flexural sandwich panel syntactic foam were also carried out using the FEA approach to predict the properties’ behaviour in this study. It was found that the micro strain for SG1 for FEA was 17% higher than the experimental value, even though they were at the same loading setting. However, the prediction for the micro strain of SG2 was only 2.7% different, which was considered a good agreement to predict the properties of syntactic foam core sandwich panel for different loading values.

Lecture Notes in Mechanical Engineering, 2019

The drag or the resistance contribution of appendages such as brackets, skegs, shafts, rudders an... more The drag or the resistance contribution of appendages such as brackets, skegs, shafts, rudders and fin stabilizers fitted to R/V Athena were investigated. The issue in estimating the appendage drag is that laminar flows occurred at lower Reynolds number typically in ship model used for ship hydrodynamic testing in a towing tank. In full-scale ship, the flow is usually turbulent. Uncertainties when scaling the model result to full-scale may arise as the flow regime in both cases are not similar, hence the full-scale estimate will be inaccurate. One method to resolve this issue is to scale the appendage drag using a fixed fraction which is known as the ‘Beta’ approach. The aim of this investigation was to determine the value of beta. R/V Athena was chosen as the case study in this investigation. The results obtained from SHIPFLOW 6.3 shows that the drag in model scale increased at 14% when fully appended. The drag in full-scale increased at 11% when fully appended. It was observed tha...

Offshore vessels (OVs) often requires precise station-keeping and some vessels, for example, vess... more Offshore vessels (OVs) often requires precise station-keeping and some vessels, for example, vessel involves in geotechnical drilling generally use Spread Mooring (SM) or Dynamic Positioning (DP) systems. Most of these vessels are equipped with both systems to cover all ranges of water depths. However, determining which systems to use for a particular operational scenario depends on many factors and requires significant balancing in terms of cost-benefit. Therefore, this research aims to develop a platform that will determine the cost factors for both the SM and DP station keeping systems. Operational information and cost data are collected for several field operations, and Artificial Neural Networks (ANN) is trained using those data samples. After that, the trained ANN is used to predict the components of cost for any given environmental situation, fieldwork duration and water depth. Later, the total cost is investigated against water depth for both DP and SM systems to determine t...

Volume 7A: Ocean Engineering, 2018

This paper focuses on getting optimised ship trajectories in narrow waterways under wind disturba... more This paper focuses on getting optimised ship trajectories in narrow waterways under wind disturbances considering time as an objective function, i.e. the ship tends to sail by taking the optimised rudder output for minimum time manoeuvre. Non-linear programming (NLP) has been proposed to use with weighted sigmoid function as non-equality constraints to follow up the reference line if it is necessary. Problems with different boundary conditions and disturbance values have been investigated to justify the effectiveness of the proposed method. The problem regarding the initial value for the start-up of the optimisation process has also been resolved by applying a systematic technique for this method.

CFD Letters, 2021

The use of fossil fuels on commercial ships significantly contributes to the increase of carbon d... more The use of fossil fuels on commercial ships significantly contributes to the increase of carbon dioxide emission, and adaptation of renewable energy can help control that emission efficiently. Historically, the extraction of wind energy is found to be the best renewable energy solution for commercial ships; and recently, with renewed interest in this area, various wind energy extraction devices are proposed in the literature. This study investigates the effectiveness of one such technology, wing-sail, on a tanker ship. The NACA 4412 series is adopted to design the sail in this regard, and a fowler flap is added to aid the sail in low wind speed. ANSYS Fluent is used to carry out this CFD simulation-based study. The effects of onboard wing-sails under various apparent wind angles, wind speeds, and wing-sail orientations have been examined. The impact of wing-sail on the stability of the ship is also analyzed. It is concluded that the ship can save fuel and reduce carbon dioxide emiss...

International Journal of Innovative Technology and Exploring Engineering, 2019

An Artificial Neural Network is a well-known AI technique for replicating human brain and offerin... more An Artificial Neural Network is a well-known AI technique for replicating human brain and offering suitable solution for any unpredictable complicated problem. Taking the advantage of it, this research will analyse the applicability of Neural Network Controller for ship manoeuvring, such as course changing. To train the controller, optimized teaching data are used to keep the consistency in the data as it could enhance the learning ability of the controller while training. A double layered feed-forward neural network and back propagation method are found suitable for this purpose. Later-on, simulations are done to justify the effectiveness of the trained controller for unknown situations.

International Journal of Innovative Technology and Exploring Engineering, 2019

Post Swirl Stator (PSS), also known as the 'Energy Saving Device (ESD) Behind the Propeller&#... more Post Swirl Stator (PSS), also known as the 'Energy Saving Device (ESD) Behind the Propeller' operates within the slip stream of the propeller. The aim of this project is to investigate the powering performance of a JAPAN Bulk Carrier (JBC) upon the installation of PSS. The prediction of resistance and propulsive factors were conducted using CFD simulation using SHIPFLOW CFD code. In order to find the optimised design of the ESD, three parameters were laid out and studied. The parameters are the left side fin length, right side fin length and the orientation of the fins.The aim of this study are to improvise the thrust fin design by changing the parameters to get the optimum powering performance result, and to quantify the powering performance of the JBC upon the installation of PSS in model and full scale. There were 27 different post-swirl stator configurations. All the 27 different configurations were compared in terms of its performance in model and full scale. All the 27...

TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation, 2015

In this paper, consistently trained Artificial Neural Network controller for automatic ship berth... more In this paper, consistently trained Artificial Neural Network controller for automatic ship berthing is discussed. Minimum time course changing manoeuvre is utilised to ensure such consistency and a new concept named 'virtual window' is introduced. Such consistent teaching data are then used to train two separate multi-layered feed forward neural networks for command rudder and propeller revolution output. After proper training, several known and unknown conditions are tested to judge the effectiveness of the proposed controller using Monte Carlo simulations. After getting acceptable percentages of success, the trained networks are implemented for the free running experiment system to judge the network's real time response for Esso Osaka 3-m model ship. The network's behaviour during such experiments is also investigated for possible effect of initial conditions as well as wind disturbances. Moreover, since the final goal point of the proposed controller is set at some distance from the actual pier to ensure safety, therefore a study on automatic tug assistance is also discussed for the final alignment of the ship with actual pier. http://www.transnav.eu the International Journal on Marine Navigation and Safety of Sea Transportation Volume 9 Number 3

IFAC-PapersOnLine, 2016

Guidance systems usually calculate the ship's desired course based on given waypoints or trajecto... more Guidance systems usually calculate the ship's desired course based on given waypoints or trajectory. In this paper, a fuzzy reasoned waypoint controller is discussed. The control laws considered here is similar to collision avoidance rules. However, instead of collision risk, nearness is reasoned by the fuzzy controller based on human operator's manipulating experience. Depending on the nearness of next and second next waypoint one at a time, fuzzy controller decides the desired heading. By this way, the necessity of calculating the circle of acceptance radius or path curvature separately at each turning point is eliminated. After getting the desired heading, as a course keeping controller, PD is used to correct the instantaneous heading. The proposed controller simplifies the total control design process and easily applicable to practical navigation path planning. Simulations with different sets of waypoints are carried out to justify the effectiveness of the proposed controller. Several experiment results are also included in this paper which validates the proposed control algorithm.

2014 13th International Conference on Control Automation Robotics & Vision (ICARCV), 2014

Manoeuvring ship during berthing has always required vast experience, skill and knowledge to prov... more Manoeuvring ship during berthing has always required vast experience, skill and knowledge to provide desired necessary actions. Presence of environmental disturbances as well as decreased manoeuvrability in low speed often makes the whole procedure so sophisticated that even slight mistake may results catastrophic disaster. By knowing the fact that Artificial Neural Network (ANN) has the ability to replicate human brains and good enough for controlling such multi-input multi-out nonlinear system, at the beginning of this research, consistent teaching data are created using Non Linear Programing (NPL) method and a new concept named 'virtual window' is introduced. Later on, considering gust wind disturbances, two separate multilayer feed forward networks are trained using back propagation technique for command rudder and propeller revolution output. After being successful in simulation works, real time berthing experiments are carried out for Esso Osaka 3-m model where the ship is planned to successfully stop within a distance of 1.5L from actual pier to ensure safety. Finally, as a current status, PD controlled side thrusters are included in order to shake hand with current controller to align the ship with pier considering wind up to 1.5 m/s for model ship.

IFAC Proceedings Volumes, 2014

Experiment results are often worthy and would be a great topic of discussion. Since many years, r... more Experiment results are often worthy and would be a great topic of discussion. Since many years, research on automatic ship berthing had already been going on to make it actually possible so that one can minimize the annual cost of dock damage as well to ensure safe operation for such sophisticated multi input-multi output phenomenon. But, success up to the extent to execute it in real cases not yet possible. Recently upon developing the unique concept named 'virtual window', the authors of this paper had already challenged the automatic ship berthing for Esso Osaka 3-m model even considering wind disturbances up to 1.5 m/s which is 15 m/s for full scale ship and considered as dead end for most ports in Japan. After getting success, for the first time using this concept, automatic ship berthing is planned and executed for free running experiment. This paper is aimed to publish some of valuable experiment results in categorised way depending on behavior of Artificial Neural Network which is used as a controller during the berthing manoeuvre.

Energies, 2020

The purpose of this paper is to estimate the H-Darrieus wind turbine aerodynamic performance, aer... more The purpose of this paper is to estimate the H-Darrieus wind turbine aerodynamic performance, aerodynamic blade loads, and velocity profiles downstream behind the rotor. The wind turbine model is based on the rotor designed by McDonnell Aircraft Company. The model proposed here consists of three fixed straight blades; in the future, this model is planned to be developed with controlled blades. The study was conducted using the unsteady Reynolds averaged Navier–Stokes (URANS) approach with the k-ω shear stress transport (SST) turbulence model. The numerical two-dimensional model was verified using two other independent aerodynamic approaches: a vortex model and the extended version of the computational fluid dynamics (CFD) code FLOWer. All utilized numerical codes gave similar result of the instantaneous aerodynamic blade loads. In addition, steady-state calculations for the applied airfoils were also made using the same numerical model as for the vertical axis wind turbine (VAWT) to...

WMU Journal of Maritime Affairs

The use of maritime autonomous vessels for the inland waterway (IWW) transport can revolutionise ... more The use of maritime autonomous vessels for the inland waterway (IWW) transport can revolutionise the current logistics supply chain and enable the shifting of the cargo transportation from the less efficient road and rail transport modes. However, the lack of guidelines and requirements for the operation and testing of autonomous vessels must be addressed to enable autonomous operations. This study aims to identify the gaps of the prevailing regulatory, liability and insurance frameworks and propose viable recommendations for the operation and testing of the autonomous IWW vessels. The theoretical case study of a next-generation autonomous ship operating in European IWW along with the required key enabling technologies is considered. A systematic methodological approach is followed focusing on the existing, transition and next-generation stages for developing autonomous vessels. The existing stage deals with classifying the identified gaps considering the categories of high, moderat...

Lecture notes in electrical engineering, 2023

ASEAN Engineering Journal, Aug 31, 2022

Research and development on sustainable alternatives to fossil fuels have become a prime focus fo... more Research and development on sustainable alternatives to fossil fuels have become a prime focus for the last couple of decades. Hydrogen, one of Earth's most abundant elements, holds great potential as a sustainable energy carrier. However, as Hydrogen is lighter than air, it does not exist in pure form in the atmosphere and is often found in compounds, such as water. The abundance of seawater in this regard makes Hydrogen an almost inexhaustible source of energy. Nevertheless, sustainable ways of extracting Hydrogen from water, dealing with its high corrosiveness and significantly lower evaporation point, still pose research challenges. Therefore, this paper aims at providing a comprehensive analysis of sustainable Hydrogen generation by focussing on the application of electrolysis to recover Hydrogen from water rather than using common reforming techniques. Different parameters affecting the efficiency and the overall performance of the electrolyser process have also been discussed and possible solutions to tackle the problems are presented. Later, a case study has been conducted to demonstrate the sustainable alternative for hydrogen production for an alkaline electrolyser using solar energy. MATLAB Simulink platform is used in this regard. This paper concludes that at an irradiation level of 1000W/m2, a PV array with 57 parallel strings with four modules connected in series per string is sufficient to provide enough power for the electrolyser to produce Hydrogen.

ASEAN Engineering Journal

Over the past decades, the attenuation of axial vibration due to propeller excitation has long be... more Over the past decades, the attenuation of axial vibration due to propeller excitation has long been a complex problem due to the coupling dynamics of the propeller-shafting system. As axial vibration is often the cause of fatigue damage to the propulsion shaft components as well as the root cause to acoustical radiation along a hull of a ship, there has been continuous interest in understanding the complex dynamic characteristics of the coupled propeller-shaft system and the methods to suppress the axial vibration in the system. Therefore, several studies have been conducted to solve this vibration problem on the longitudinal axis of the marine propulsion shafting system. This paper aims to provide the theoretical foundations of this problem by reviewing the modelling techniques of this coupled dynamic problem and cover the vibration reduction strategies that are proposed by the cited studies.

Advanced Maritime Technologies and Applications, 2022

Agriculture, 2021

Assessment of possible changes in crops water stress due to climate alteration is essential for a... more Assessment of possible changes in crops water stress due to climate alteration is essential for agricultural planning, particularly in arid regions where water supply is the major challenge for agricultural development. This study aims to project climatic water availability (CWA) and crop water demand (CWD) to outline the possible future agricultural water stress of Iraq for different radiative concentration pathways (RCPs). The ensemble means of downscaled precipitation and temperature projections of the selected global climate models (GCMs) were used in a simple water balance model for this purpose. The modified Mann–Kendall (mMK) trend test was employed to estimate the tendency in CWA and the Wilcoxon rank test to evaluate CWD alteration in three future time horizons compared to the base period (1971–2000). The results revealed a decrease in CWA at a rate of up to −34/year during 2010–2099 for RCP8.5. The largest declination would be in summer (−29/year) and an insignificant decr...

Lecture Notes in Mechanical Engineering, 2019

The investigation on the strain value for flexural sandwich panel syntactic foam were also carrie... more The investigation on the strain value for flexural sandwich panel syntactic foam were also carried out using the FEA approach to predict the properties’ behaviour in this study. It was found that the micro strain for SG1 for FEA was 17% higher than the experimental value, even though they were at the same loading setting. However, the prediction for the micro strain of SG2 was only 2.7% different, which was considered a good agreement to predict the properties of syntactic foam core sandwich panel for different loading values.

Lecture Notes in Mechanical Engineering, 2019

The drag or the resistance contribution of appendages such as brackets, skegs, shafts, rudders an... more The drag or the resistance contribution of appendages such as brackets, skegs, shafts, rudders and fin stabilizers fitted to R/V Athena were investigated. The issue in estimating the appendage drag is that laminar flows occurred at lower Reynolds number typically in ship model used for ship hydrodynamic testing in a towing tank. In full-scale ship, the flow is usually turbulent. Uncertainties when scaling the model result to full-scale may arise as the flow regime in both cases are not similar, hence the full-scale estimate will be inaccurate. One method to resolve this issue is to scale the appendage drag using a fixed fraction which is known as the ‘Beta’ approach. The aim of this investigation was to determine the value of beta. R/V Athena was chosen as the case study in this investigation. The results obtained from SHIPFLOW 6.3 shows that the drag in model scale increased at 14% when fully appended. The drag in full-scale increased at 11% when fully appended. It was observed tha...

Offshore vessels (OVs) often requires precise station-keeping and some vessels, for example, vess... more Offshore vessels (OVs) often requires precise station-keeping and some vessels, for example, vessel involves in geotechnical drilling generally use Spread Mooring (SM) or Dynamic Positioning (DP) systems. Most of these vessels are equipped with both systems to cover all ranges of water depths. However, determining which systems to use for a particular operational scenario depends on many factors and requires significant balancing in terms of cost-benefit. Therefore, this research aims to develop a platform that will determine the cost factors for both the SM and DP station keeping systems. Operational information and cost data are collected for several field operations, and Artificial Neural Networks (ANN) is trained using those data samples. After that, the trained ANN is used to predict the components of cost for any given environmental situation, fieldwork duration and water depth. Later, the total cost is investigated against water depth for both DP and SM systems to determine t...

Volume 7A: Ocean Engineering, 2018

This paper focuses on getting optimised ship trajectories in narrow waterways under wind disturba... more This paper focuses on getting optimised ship trajectories in narrow waterways under wind disturbances considering time as an objective function, i.e. the ship tends to sail by taking the optimised rudder output for minimum time manoeuvre. Non-linear programming (NLP) has been proposed to use with weighted sigmoid function as non-equality constraints to follow up the reference line if it is necessary. Problems with different boundary conditions and disturbance values have been investigated to justify the effectiveness of the proposed method. The problem regarding the initial value for the start-up of the optimisation process has also been resolved by applying a systematic technique for this method.

CFD Letters, 2021

The use of fossil fuels on commercial ships significantly contributes to the increase of carbon d... more The use of fossil fuels on commercial ships significantly contributes to the increase of carbon dioxide emission, and adaptation of renewable energy can help control that emission efficiently. Historically, the extraction of wind energy is found to be the best renewable energy solution for commercial ships; and recently, with renewed interest in this area, various wind energy extraction devices are proposed in the literature. This study investigates the effectiveness of one such technology, wing-sail, on a tanker ship. The NACA 4412 series is adopted to design the sail in this regard, and a fowler flap is added to aid the sail in low wind speed. ANSYS Fluent is used to carry out this CFD simulation-based study. The effects of onboard wing-sails under various apparent wind angles, wind speeds, and wing-sail orientations have been examined. The impact of wing-sail on the stability of the ship is also analyzed. It is concluded that the ship can save fuel and reduce carbon dioxide emiss...

International Journal of Innovative Technology and Exploring Engineering, 2019

An Artificial Neural Network is a well-known AI technique for replicating human brain and offerin... more An Artificial Neural Network is a well-known AI technique for replicating human brain and offering suitable solution for any unpredictable complicated problem. Taking the advantage of it, this research will analyse the applicability of Neural Network Controller for ship manoeuvring, such as course changing. To train the controller, optimized teaching data are used to keep the consistency in the data as it could enhance the learning ability of the controller while training. A double layered feed-forward neural network and back propagation method are found suitable for this purpose. Later-on, simulations are done to justify the effectiveness of the trained controller for unknown situations.

International Journal of Innovative Technology and Exploring Engineering, 2019

Post Swirl Stator (PSS), also known as the 'Energy Saving Device (ESD) Behind the Propeller&#... more Post Swirl Stator (PSS), also known as the 'Energy Saving Device (ESD) Behind the Propeller' operates within the slip stream of the propeller. The aim of this project is to investigate the powering performance of a JAPAN Bulk Carrier (JBC) upon the installation of PSS. The prediction of resistance and propulsive factors were conducted using CFD simulation using SHIPFLOW CFD code. In order to find the optimised design of the ESD, three parameters were laid out and studied. The parameters are the left side fin length, right side fin length and the orientation of the fins.The aim of this study are to improvise the thrust fin design by changing the parameters to get the optimum powering performance result, and to quantify the powering performance of the JBC upon the installation of PSS in model and full scale. There were 27 different post-swirl stator configurations. All the 27 different configurations were compared in terms of its performance in model and full scale. All the 27...

TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation, 2015

In this paper, consistently trained Artificial Neural Network controller for automatic ship berth... more In this paper, consistently trained Artificial Neural Network controller for automatic ship berthing is discussed. Minimum time course changing manoeuvre is utilised to ensure such consistency and a new concept named 'virtual window' is introduced. Such consistent teaching data are then used to train two separate multi-layered feed forward neural networks for command rudder and propeller revolution output. After proper training, several known and unknown conditions are tested to judge the effectiveness of the proposed controller using Monte Carlo simulations. After getting acceptable percentages of success, the trained networks are implemented for the free running experiment system to judge the network's real time response for Esso Osaka 3-m model ship. The network's behaviour during such experiments is also investigated for possible effect of initial conditions as well as wind disturbances. Moreover, since the final goal point of the proposed controller is set at some distance from the actual pier to ensure safety, therefore a study on automatic tug assistance is also discussed for the final alignment of the ship with actual pier. http://www.transnav.eu the International Journal on Marine Navigation and Safety of Sea Transportation Volume 9 Number 3

IFAC-PapersOnLine, 2016

Guidance systems usually calculate the ship's desired course based on given waypoints or trajecto... more Guidance systems usually calculate the ship's desired course based on given waypoints or trajectory. In this paper, a fuzzy reasoned waypoint controller is discussed. The control laws considered here is similar to collision avoidance rules. However, instead of collision risk, nearness is reasoned by the fuzzy controller based on human operator's manipulating experience. Depending on the nearness of next and second next waypoint one at a time, fuzzy controller decides the desired heading. By this way, the necessity of calculating the circle of acceptance radius or path curvature separately at each turning point is eliminated. After getting the desired heading, as a course keeping controller, PD is used to correct the instantaneous heading. The proposed controller simplifies the total control design process and easily applicable to practical navigation path planning. Simulations with different sets of waypoints are carried out to justify the effectiveness of the proposed controller. Several experiment results are also included in this paper which validates the proposed control algorithm.

2014 13th International Conference on Control Automation Robotics & Vision (ICARCV), 2014

Manoeuvring ship during berthing has always required vast experience, skill and knowledge to prov... more Manoeuvring ship during berthing has always required vast experience, skill and knowledge to provide desired necessary actions. Presence of environmental disturbances as well as decreased manoeuvrability in low speed often makes the whole procedure so sophisticated that even slight mistake may results catastrophic disaster. By knowing the fact that Artificial Neural Network (ANN) has the ability to replicate human brains and good enough for controlling such multi-input multi-out nonlinear system, at the beginning of this research, consistent teaching data are created using Non Linear Programing (NPL) method and a new concept named 'virtual window' is introduced. Later on, considering gust wind disturbances, two separate multilayer feed forward networks are trained using back propagation technique for command rudder and propeller revolution output. After being successful in simulation works, real time berthing experiments are carried out for Esso Osaka 3-m model where the ship is planned to successfully stop within a distance of 1.5L from actual pier to ensure safety. Finally, as a current status, PD controlled side thrusters are included in order to shake hand with current controller to align the ship with pier considering wind up to 1.5 m/s for model ship.

IFAC Proceedings Volumes, 2014

Experiment results are often worthy and would be a great topic of discussion. Since many years, r... more Experiment results are often worthy and would be a great topic of discussion. Since many years, research on automatic ship berthing had already been going on to make it actually possible so that one can minimize the annual cost of dock damage as well to ensure safe operation for such sophisticated multi input-multi output phenomenon. But, success up to the extent to execute it in real cases not yet possible. Recently upon developing the unique concept named 'virtual window', the authors of this paper had already challenged the automatic ship berthing for Esso Osaka 3-m model even considering wind disturbances up to 1.5 m/s which is 15 m/s for full scale ship and considered as dead end for most ports in Japan. After getting success, for the first time using this concept, automatic ship berthing is planned and executed for free running experiment. This paper is aimed to publish some of valuable experiment results in categorised way depending on behavior of Artificial Neural Network which is used as a controller during the berthing manoeuvre.