Authors: Zakartchouk Junior, Alexis; Morishita, Helio Mitio

Abstract: Dynamic Positioning System (DPS) is a complex control system composed of several algorithms, such as controllers, filters and optimal thrust allocation. The design, analysis and performance prediction of a DPS are normally done by a combination of numerical simulations and tank tests with a reduced model. This paper presents a comparison of numerical and preliminary experimental results of a dynamic-positioned shuttle tanker model, using a backstepping controller.

Keywords: Offshore systems modelling and control; Ship manoeuvring; Surface ship track control

Identifier: 10.3182/20090916-3-BR-3001.00063

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Chaos, Dictino; Moreno Salinas, David; Aranda, Joaquin; de la Cruz, Jesús M

Abstract: Control design for marine autonomous vehicles is a subject of great interest in the control systems. These vehicles are strongly non linear and show complex hydrodynamics effects that make difficult the control design. Besides, the use of underactuated vehicles is very important for different reasons like simplicity, cost, efficiency, etc, so these vehicles and their use for collaborative tasks are main topics of investigation. A non linear control for path following for USVs is presented in this work with an infrastructure capable of performing multiple AUV and ROV in collaborative tasks. So this control law and this infrastructure will be used in future projects for formation control of USVs

Keywords: Navigation, guidance and control of autonomus surface and underwater vehicles; Control of remotely operated vehicles (ROVs); Architectures for teams of robotic marine vehicles

Identifier: 10.3182/20090916-3-BR-3001.00041

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Jensen, Gullik Anthon; Fossen, Thor I.

Abstract: In this paper a robotic approach is taken to develop a dynamic nonlinear model of an offshore pipeline installation. A compact dynamic representation of the pipe and its kinematics, for effective implementation in a computer code is developed. The pipe model is used in simulations to compute the dynamic tension from the pipe on the vessel. The pipe tension is commonly computed by quasi-static methods based on the catenary equation, which lack the dynamic behavior and flexural effects of the pipe. The model can also replace computationally slower finite element models in applications with real-time requirements. The model is suitable for many applications, such as real-time decision support, training simulators, motion prediction systems, Hardware-In-the-Loop (HIL) testing, operability analysis, control applications and pre-design of ships.

Keywords: Offshore systems modelling and control

Identifier: 10.3182/20090916-3-BR-3001.00019

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Ruth, Eivind; Soerensen, Asgeir

Abstract: In oil and gas exploration and exploitation many ships and rigs use dynamic positioning (DP) systems for maintaining a fixed position. The DP system usually contains a thrust allocator, which maps the desired generalized forces into individual actuator commands. For over actuated vessels the solution is usually obtained by some kind of optimization. If the thrust allocation problem constitutes a convex problem, a global solution is found easily. However, this is not always the case in real life, where directional constraints on the azimuthing thrusters imposed by e.g. under water equipment may make the problem nonconvex. This paper presents a mixed integer approach to the nonconvex linearly constrained quadratic thrust allocation problem by switching between convex subproblems. The method is demonstrated by experiments.

Keywords: Thrusters and propulsion systems; Offshore systems modelling and control; Ship manoeuvring

Identifier: 10.3182/20090916-3-BR-3001.00030

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Lampe, Bernhard P.; Korte, Holger; Kurowski, Martin

Abstract: According to their tasks and relations, specialized vessels are equipped with modern steering devices like podded drives or thrusters. Such modern steering concepts substantially increase the manoeuvring capability of the vessels. However, mates are not able to handle those gears efficiently, because the relations between action and reaction are far too complex. Automation is needed to support the steering team. The industrial production of wheelhouse systems within the large spectrum of types of manoeuvring gears and their location on vessel hulls is still a hard problem. Finally, each adaptation for the navigation and track guidance system looks like an individual system production. For an easier prototyping and implementation of different steering concepts in navigation and track guidance systems for vessels, a modular concept has been applied by the University of Rostock, Center for Marine Information Systems (CeMarIS). Supported by the Federal Ministry of Economics and Technology, in the joint project ``Adaptive Navigation System for Ships'' the control of each device was implemented into a new automation strategy for the guidance process to realize an optimal manoeuvrability in motion. At the end of the project, final tests in the Maritime Simulation Center in Warnemuende (MSCW) have demonstrated the efficiency of the developed modular control concepts.

Keywords: Ship manoeuvring; Ship autopilots; Surface ship track control

Identifier: 10.3182/20090916-3-BR-3001.00013

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Carletti, Cristina; Ippoliti, Gianluca; Longhi, Sauro; Orlando, Giuseppe

Abstract: The paper describes an adaptive neural network based sliding mode control for fin roll stabilization of ocean motoryachts. Radial basis function neural networks are used to adaptively learn system uncertainty bounds and network outputs are used to adjust the gain of the sliding mode control. The analysis of the control stability is based on the Lyapunov theory. The proposed controller is tested by a simulation study based on a nonlinear model, describing the dynamics of a vessel in four degrees of freedom. On this manoeuvring model output sea state disturbance are simulated as multisine time series.

Keywords: Roll damping; Ship manoeuvring; High speed vessels

Identifier: 10.3182/20090916-3-BR-3001.00052

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Perez, Tristan

Abstract: This paper presents a framework for the design of a joint motion controller and a control allocation strategy for dynamic positioning of marine vehicles. The key aspects of the proposed designs are a systematic approach to deal with actuator saturation and to inform the motion controller about saturation. The proposed system uses a mapping that translates the actuator constraint sets into constraint sets at the motion controller level. Hence, while the motion controller addresses the constraints, the control allocation algorithm can solve an unconstrained optimisation problem. The constrained control design is approached using a multivariable anti-wind-up strategy for strictly proper controllers. This is applicable to the implementation of PI and PID type of motion controllers.

Keywords: Offshore systems modelling and control

Identifier: 10.3182/20090916-3-BR-3001.00038

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Corradini, Maria Letizia; Monteriù, Andrea; Orlando, Giuseppe

Abstract: This paper presents a preliminary set of results on the design of an Actuator Failure Tolerant Control Systems for an underwater remotely operated vehicle (ROV). The approach consists of two phases. First a model-based approach is applied to the nonlinear model of the ROV for failure detection purposes. Successively, using a Sliding Mode Control based approach, the failure is isolated and the control law is reconfigured using the remaining working actuators.

Keywords: Control of remotely operated vehicles (ROVs); Thrusters and propulsion systems; Operational safety

Identifier: 10.3182/20090916-3-BR-3001.00042

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Yamamoto, Marcio; Morooka, Celso Kazuyuki

Abstract: Offshore Petroleum Industry regularly uses the automatic control to keep the positioning of floating drilling platforms and, in a few exceptions, floating production platforms. This positioning control system is commonly denominated Dynamic Positioning System (DPS). This automatic control measures the platform position through a gyrocompass for the heading, and a Differential Global Positioning System (DGPS) and/or an Acoustic Positioning System for translational displacements. Further, the thrusters installed on the platform hull are the actuators bringing the platform to the reference position. This work presents the dynamics of semi-submersible drilling platform equipped with DPS and coupled with a drilling riser in 3000 m water depth. In addition, a special attention is paid on the drilling operation called well re-entry. During the re-entry, a safety equipment named Blow Out Preventer (BOP) is lowered down attached to the drilling riser, and the BOP shall be connected onto the wellhead. This approaching of the BOP to the wellhead is carried out controlling the floating platform manually, with the help of a camera attached to a Remote Operated Vehicle (ROV) which shows how far the BOP is from the wellhead. Then, the engaged personnel estimates this distance and changes the reference position of the DPS in order to reduce this distance. In this paper, numerical simulation results for the coupled platform and riser dynamics are featured and discussion about an extra feedback loop that could control the BOP approach automatically in the re-entry operation is presented.

Keywords: Offshore systems modelling and control

Identifier: 10.3182/20090916-3-BR-3001.00062

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Perez, Tristan; Steinmann, Paul

Abstract: The use of dedicated spinning wheels that generate gyroscopic forces for reducing the roll motion of ships was considered and tested over 100 years ago. These devices, known as gyrostabilisers, presented a remarkable performance, but they fell into disuse due to their relatively large size and, primarily, due to the inability of the control systems to maintain performance over an extended envelope of sea states and sailing conditions (speed and heading relative to the waves). To date, advances in materials, mechanical design, electrical drives, and computer control systems have resulted in a revitalized interest in gyro-stabilisers for ships. This paper revisits the modelling of the coupled vessel-gyrostabiliser and delves into the associated gyrostabiliser control design problem. It also describes design trade-offs and potential performance limitations. A simulation study based on a navy patrol vessel is presented.

Keywords: Roll damping; Offshore systems modelling and control

Identifier: 10.3182/20090916-3-BR-3001.00050

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: None

Abstract:

Keywords:

Identifier: 10.3182/20090916-3-BR-3001.90003

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Wilson, Philip

Abstract: This paper briefly introduces a strategy for autonomous homing and docking tasks using an autonomous underwater vehicle. The control and guidance based path following for those tasks are described in this work. A standard sliding mode for controller design is briefly given. The method provides robust motion control efforts for an underwater vehicle’s decoupled system whilst minimising chattering effects. In a guidance system, the vector field based on a conventional artificial potential field method gives a desired trajectory with a use of existing information from sensors in the network. A well structured Line-of-Sight method is used for an AUV to follow the path. It provides guidance for an AUV to follow the predefined trajectory to a required position with the final desired orientation at the dock. Integration of a control and guidance system provides a complete system for this application. Simulation studies are illustrated in the paper.

Keywords: Navigation, guidance and control of autonomus surface and underwater vehicles; Control of remotely operated vehicles (ROVs); Sensors and sensor integration in autonomus robots

Identifier: 10.3182/20090916-3-BR-3001.00049

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Benitez, Jose Maria; Jimenez, Juan F; Giron-Sierra, Jose M

Abstract: A new path planning method with guaranteed trajectory feasibility is proposed for ships. The method follows two steps: the first is based on cellular automata, the second on ant colony optimization. Some succesful examples are shown.

Keywords: Ship manoeuvring; Intelligent marine control systems

Identifier: 10.3182/20090916-3-BR-3001.00032

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Alme, Jon; Breivik, Morten

Abstract: This paper considers aspects related to the problem of automatic tuning (autotuning) of dynamic positioning (DP) controllers for marine surface vessels. Autotuning involves automatic adjustment of controller parameters for shifting vessel operational conditions (VOCs), which encompass changing vessel dynamics and different operational tasks. A controller with fixed gains cannot behave equally well for all VOCs and autotuning can thus be very valuable in practice, saving time for commissioning and improving operational robustness. In this work, we review some previous work and discuss fundamental concepts within the subject area. We also propose a novel performance index for station-keeping purposes and use this index together with an autotuning algorithm which employs data generated from the index. Finally, some simulation results concerning station keeping of an offshore supply vessel operating in challenging sea-state conditions are included.

Keywords: Offshore systems modelling and control; Surface ship track control; Intelligent marine control systems

Identifier: 10.3182/20090916-3-BR-3001.00054

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Paredes Aguilar, Lizbeth Leonor; Donha, Decio Crisol

Abstract: The design and implementation of a control layer architecture used to control the motions of a Semi Autonomous Underwater Vehicle (SAUV) is focused and presented. At first, the main functionalities required for navigation, guidance and collision avoidance during missions of marine robots are drafted to facilitate the understanding of the whole design process. After that, a set of rules are created, seeking to guarantee the consistency and correctness of the control system operation. A modular topology is employed to establish this set of rules, i.e. input-output relationships are clearly defined at each execution level, ruled through constraints established through an algorithm based on fuzzy logic. The control system itself is subdivided into three layers. Extensive simulation studies are then performed using the configuration of a vehicle under construction. The main advantages of the proposed navigation control architecture lies in its simplicity, modularity and flexibility, leading to a high performance of the control system.

Keywords: Navigation, guidance and control of autonomus surface and underwater vehicles; Intelligent marine control systems; Control of remotely operated vehicles (ROVs)

Identifier: 10.3182/20090916-3-BR-3001.00035

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Cutipa Luque, Juan Carlos; Donha, Decio Crisol

Abstract: An extended Kalman filter is used to tackle the problem of parameter identification of an autonomous underwater vehicle (AUV). Since a large number of parameters must be identified, two alternative sub-approaches are investigated. A classical approach seems to have a better performance in cases where a specific parameter will be identified. However, a modified approach guarantees a better identification when dealing with multiple parameters. A sway/yaw mathematical model for an AUV is obtained considering motions in the horizontal plane. Circular and zig-zag maneuvers are tested to assess the identification approaches employed. Results are presented and analysed.

Keywords: Navigation, guidance and control of autonomus surface and underwater vehicles; Offshore systems modelling and control

Identifier: 10.3182/20090916-3-BR-3001.00010

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Caccia, Massimo; Bibuli, Marco; Bono, Riccardo; Bruzzone, Gabriele; Bruzzone, Giorgio; Spirandelli, Edoardo

Abstract: This paper, that surveys the characteristic of the Charlie USV, is the first one of the proposed special session "Experimental research on USVs: the Charlie experience". The Charlie USV, originally developed for the sampling of sea surface microlayer and exploited in the Italian Antarctic expedition 2003-'04, in the last four years has been supporting research in the field of unmanned marine vehicles. In particular, this prototype vehicle allowed the experimental validation of algorithms and methodologies proposed and developed by different research groups cooperating on the basis of heterogeneous programs. The supported research mainly focused on embedded real-time platforms for robotics and industrial automation; modelling and identification; basic navigation, guidance and control; straight line and generic path following; cooperative mission control and path-following. This paper, after a brief description of the electro-mechanical design and general software, control and communication architecture of the vehicle, discusses the critical aspects, in the authors' opinion, in facilitating its use as a testbed supporting cooperation between different research groups: light logistics, integration with a hardware-in-the-loop simulator, execution control level automatically handling task dependencies and conflicts, task description in terms of I/O and state variables, standard and free tools for developing application code.

Keywords: Intelligent marine control systems; Navigation, guidance and control of autonomus surface and underwater vehicles; Sensors and sensor integration in autonomus robots

Identifier: 10.3182/20090916-3-BR-3001.00014

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Alves, Joao; Brignone, Lorenzo; Schneider, Matthias; Kalwa, Joerg

Abstract: -

Keywords: Cooperative control under severe communication constraints; Cooperative navigation and control of Multiple Marine Vehicle Systems

Identifier: 10.3182/20090916-3-BR-3001.00059

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Burger, Mernout; Pavlov, Alexey; Pettersen, Kristin Y.

Abstract: The problem of controlling a vessel in the presence of unknown, constant disturbances requires employment of robust or adaptive control methods, like control with integral action, sliding mode control or adaptive control. All these methods have their benefits and drawbacks. In this paper we propose the use of conditional integrators in the field of marine control. Conditional integrators have the robustness of integral action and sliding mode control, while avoiding their inherent drawbacks like chattering and integrator wind-up. An application of conditional integrator to path following and formation control problems for marine vessels affected by external disturbances is discussed. The effectiveness of the obtained controller is shown by simulations.

Keywords: Cooperative navigation and control of Multiple Marine Vehicle Systems; Navigation, guidance and control of autonomus surface and underwater vehicles; Intelligent marine control systems

Identifier: 10.3182/20090916-3-BR-3001.00027

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Aguiar, A. Pedro; Almeida, João; Bayat, Mohammadreza; Cardeira, Bruno Miguel; Cunha, Rita; Häusler, Andreas Johannes; Maurya, Pramod; Pascoal, Antonio M.; Pereira, Arvind; Rufino, Manuel; Sebastiao, Luis; Silvestre, Carlos; Vanni, Francesco

Abstract:

Keywords: Cooperative navigation and control of Multiple Marine Vehicle Systems; Architectures for teams of robotic marine vehicles; Cooperative control under severe communication constraints

Identifier: 10.3182/20090916-3-BR-3001.00066

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Briere, Yves; Ribeiro, Flavio Luiz Cardoso

Abstract: The design of a sailing robot controller is addressed. Based on a simulation model, and validated by experiments with a real sailing robot, three controllers are compared: the classical fuzzy controller, the state machine controller and the fuzzy state machine controller. The fuzzy controller shows poor results because the robot is, like any sailboat, subject to dramatic change in its internal state (tacking, jibe, etc.) The "natural" approach is to describe the transitions between states as a classical state machine with transitions. We improve the concept with fuzzy transition, obtaining the same results in term of behavior but using effectiveness of fuzzy design to transpose human expertise in fuzzy rules. Although our controllers show good results in a wide range of wind force we conclude by the need of some adaptive

Keywords: Navigation, guidance and control of autonomus surface and underwater vehicles; Ship autopilots; Ship manoeuvring

Identifier: 10.3182/20090916-3-BR-3001.00008

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Martiny, Nora; Sosnowski, Stefan; Kuehnlenz, Kolja; Hirche, Sandra; Nie, Yimin; Franosch, Jan-Moritz Peter; van Hemmen, J. Leo

Abstract: In an ongoing research project an autonomous underwater vehicle is to be built that will detect, localize, and avoid objects by means of a fully passive sensory system. Using hot-wire anemometry it measures local water velocities at the vehicle's hull and thus mimics the lateral-line system of fish and many amphibians. Fish often use the lateral-line system as their only means for navigation, especially under poor visual conditions. Simulations and theoretical calculations of the flow around an underwater vehicle show that velocity measurements with hot-wire anemometers enable an underwater vehicle to detect surfaces, so that no clear sight or active scanning is necessary for collision avoidance. A first series of experiments validates theoretical calculations and shows that a vehicle can detect parallel movement to a wall.

Keywords: Sensors and sensor integration in autonomus robots; Navigation, guidance and control of autonomus surface and underwater vehicles; Intelligent marine control systems

Identifier: 10.3182/20090916-3-BR-3001.00047

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Rebello de Souza, Jessé; Tannuri, Eduardo Aoun; Oshiro, Anderson Takehiro; Morishita, Helio Mitio

Abstract: This paper reports on two case studies making use of a digital simulator to investigate the manoeuvring motions of ships in canals with shallow and restricted waters. The first case study corresponds to a manoeuvring analysis conducted for the Port of Rio Grande (RS - Brazil), whose aim was to assess the potential impact upon manoeuvres of the presence of a large offshore platform (the Petrobras P-53) which is to remain docked for several months at the Port to complete its construction. The second study made use of the simulator to evaluate the manoeuvring conditions along the approach route and manoeuvring basin of the Port of Ponta do Félix (PR – Brazil). The simulator includes a complete mathematical model of the ship dynamics in the horizontal plane when subjected to wind and current forces. It also comprises detailed models for the action of thrusters and propellers, both fixed and azimuth, employed to control manoeuvres and dynamically position ships, as well as rudders and tugboats. The models used by the simulator allow for the effects of shallow and restricted waters, including the increase in resistance and lateral forces, increase in additional mass and the appearance of lateral and vertical suction (squatting). The simulator is implemented via an interactive interface through which the user is able to apply control actions (rudder angle, main engine, thrusters and tugboats) in real time during manoeuvres, thereby reproducing to some extent the action of a pilot.

Keywords: Ship manoeuvring; Thrusters and propulsion systems; Operational safety

Identifier: 10.3182/20090916-3-BR-3001.00004

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Queiroz Filho, Asdrubal do Nascimento; Tannuri, Eduardo Aoun

Abstract: The propose of this paper is to discuss the advantages obtained by the simulations of offloading operations in the presence of waves, detailing the effects that arise when body’s interactions are taken into account. Effects are sensed in the equilibrium position, on the drift’s forces and the necessary power to dynamic position system. On this paper a simulation of a real offloading operation is presented. Results are shown with and without the shielding effect.

Keywords: Offshore systems modelling and control; Thrusters and propulsion systems; Operational safety

Identifier: 10.3182/20090916-3-BR-3001.00061

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009

Authors: Samyn, Leandro; Cunha, Jose Paulo V. S.

Abstract: This paper describes a six degrees of freedom dynamic model for the development of ballast control systems for semi-submersible platforms. The dynamic model includes the effects of the ballast tanks such as weights, moments and inertias. The parameters of the dynamic model are computed from geometric data and from experimental results obtained with a small semi-submersible platform. The hull of the platform is represented by a mesh of tetrahedrons to allow the computation of the displacement and the center of buoyancy, which are important for the evaluation of the stability of the platform.

Keywords: Offshore systems modelling and control; High speed vessels; Roll damping

Identifier: 10.3182/20090916-3-BR-3001.00022

Conference: 8th IFAC International Conference on Manoeuvring and Control of Marine Craft

Location: Casa Grande Hotel, Brazil

Start Date: Wed Sep 16 2009 - End Date: Fri Sep 18 2009