The Experts below are selected from a list of 1614 Experts worldwide ranked by ideXlab platform

Vahid Hassani - One of the best experts on this subject based on the ideXlab platform.

  • adaptive boarding control system in Surface Effect Ships
    European Control Conference, 2019
    Co-Authors: Vahid Hassani, Oyvind Fidje Auestad, Snorre Fjellvang, Jan Tommy Gravdahl
    Abstract:

    This paper deals with adaptive regulation of wave induced vertical motion on a Surface Effect Ship (SES) at zero speed. To this end, a SES is equipped with variable vent valves, through which cushion pressure can be controlled by adjusting the air out-flow from the cushion. Model scale test and sea trials have shown Effectiveness of such control system. In this paper, we present an adaptive control system which automatically adjust the tuning parameters for the existing SES Motion Control System. A study of the performance of the control system is demonstrated through numerical simulation using a high fidelity model of SES subject to waves.

  • design and verification of a sway yaw control system for Surface Effect Ships using vent valves
    IFAC-PapersOnLine, 2019
    Co-Authors: Hakon Teigland, Vahid Hassani, Oyvind Fidje Auestad
    Abstract:

    Abstract For an offshore worker in the oil and gas industry, the helicopter transport is the activity associated with the highest risk. An alternative to helicopter crew transfers is to use Surface Effect Ships (SES) to transport the crew. A SES is a catamaran vessel carried in part by a pressurized air cushion. The pressure is maintained by fans and controlled using vent valves. The benefit of these vessels are the high speed to fuel consumption ratio due to decreased wave resistance. During crew transfer from the SES to the offshore installation, the position of the SES needs to be maintained within a safety region using a Dynamic Positioning (DP) system. By mounting the vent valves on the hull sides, the thrust force coming from the air exiting the vent valves can be used to act as an assistance to the DP system. This would reduce required installation power and operational cost of the DP system. Furthermore, combining the thrust from the vent valves with DP thrusters would give a DP system with a high degree of redundancy since thrust force may be generated from two different physical principles. This paper presents a sway-yaw control system for a SES to demonstrate an assisted system that is actuated purely by vent valve thrust from the pressurized cushion. The developed control system is verified using numerical simulations carried out in a high fidelity simulator.

H Oehlmann - One of the best experts on this subject based on the ideXlab platform.

  • COMPARATIVE PARAMETRIC STUDIES OF MONOHULL AND Surface Effect Ships
    1991
    Co-Authors: P Goubault, H Oehlmann
    Abstract:

    Surface Effect Ship and Monohull parametric designs were developed to common standards and common sets of requirements, using whole-ship Design Synthesis Models. The parametric designs were developed to U.S. Coast Guard Patrol-Boat Standards and the requirements included speeds ranging from 30 to 55 knots, payloads from 10 to 50 tons, range from 500 to 1500 nm and design sea-states from 0 to 4. Over 3000 SES and 3000 Monohull computer-generated parametric designs were developed to allow the optimum solutions to be selected for each set of requirements. These optimum solutions were then compared on the basis of platform acquisition cost, ship displacement and installed power. The study was conducted in three phases: Phase-I focused on developing common design standards and assumptions and on the choice of propulsor and engine types. Phase-II focused on seakeeping and the choice of seakeeping criteria. Phase-III focused on the influence of requirements on costs using the subsystem choices and ground rules established in Phases-I and II. Results are presented in the form of cost, weight and power versus requirements which provides a means of ensuring the selection of affordable requirements and, once having established a set of requirements, determining which hullform, Monohull or SES, would be the most suitable choice.

  • the prediction of resistance of Surface Effect Ships
    1991
    Co-Authors: H Oehlmann, J C Lewthwaite
    Abstract:

    MTG Marinetechnik in Hamburg has designed a large SES, called SES-700 Fast Test Craft. A 5 m long model of this design has been extensively tank tested at the David Taylor Research Centre (DTRC) in Washington D.C., USA. In addition, sea-keeping data for a number of UK SES craft have been purchased from Hovermarine International and analysed in order to extend the data-base with respect to differing hullforms and size variations. In this paper, the results of a study into the resistance of various SES in both calm water and in head seas, are presented. Generalised methods of prediction of resistance have been developed which can be applied to new designs. Several theories of the individual resistance components have been incorporated into a computer program named SESDRAG, and examples of the output from this program are given for a new SES design.

Oyvind Fidje Auestad - One of the best experts on this subject based on the ideXlab platform.

  • adaptive boarding control system in Surface Effect Ships
    European Control Conference, 2019
    Co-Authors: Vahid Hassani, Oyvind Fidje Auestad, Snorre Fjellvang, Jan Tommy Gravdahl
    Abstract:

    This paper deals with adaptive regulation of wave induced vertical motion on a Surface Effect Ship (SES) at zero speed. To this end, a SES is equipped with variable vent valves, through which cushion pressure can be controlled by adjusting the air out-flow from the cushion. Model scale test and sea trials have shown Effectiveness of such control system. In this paper, we present an adaptive control system which automatically adjust the tuning parameters for the existing SES Motion Control System. A study of the performance of the control system is demonstrated through numerical simulation using a high fidelity model of SES subject to waves.

  • design and verification of a sway yaw control system for Surface Effect Ships using vent valves
    IFAC-PapersOnLine, 2019
    Co-Authors: Hakon Teigland, Vahid Hassani, Oyvind Fidje Auestad
    Abstract:

    Abstract For an offshore worker in the oil and gas industry, the helicopter transport is the activity associated with the highest risk. An alternative to helicopter crew transfers is to use Surface Effect Ships (SES) to transport the crew. A SES is a catamaran vessel carried in part by a pressurized air cushion. The pressure is maintained by fans and controlled using vent valves. The benefit of these vessels are the high speed to fuel consumption ratio due to decreased wave resistance. During crew transfer from the SES to the offshore installation, the position of the SES needs to be maintained within a safety region using a Dynamic Positioning (DP) system. By mounting the vent valves on the hull sides, the thrust force coming from the air exiting the vent valves can be used to act as an assistance to the DP system. This would reduce required installation power and operational cost of the DP system. Furthermore, combining the thrust from the vent valves with DP thrusters would give a DP system with a high degree of redundancy since thrust force may be generated from two different physical principles. This paper presents a sway-yaw control system for a SES to demonstrate an assisted system that is actuated purely by vent valve thrust from the pressurized cushion. The developed control system is verified using numerical simulations carried out in a high fidelity simulator.

Miroslav Krstic - One of the best experts on this subject based on the ideXlab platform.

  • adaptive wave cancelation by acceleration feedback for ramp connected air cushion actuated Surface Effect Ships
    Automatica, 2013
    Co-Authors: Halil I. Basturk, Miroslav Krstic
    Abstract:

    We solve the problem of cargo transfer in high sea states over a ramp from a large, medium-speed, roll-on/roll-off (LMSR) vessel to a smaller connector vessel of a Surface Effect ship (SES) type. Our aim is to reduce ramp motion between the LMSR and SES in order to provide a safer environment for cargo transfer. We design an air cushion actuated controller to estimate and cancel the wave disturbance and stabilize the heave of the SES via heave acceleration feedback with actuation of the louver area for the case where the hydrodynamic and other parameters of the SES are not known a priori and the pressure dynamics of the air cushion contains nonlinearly parameterized unknown terms. We demonstrate the Effect of our control design in simulations in a time-domain seakeeping code, named AEGIR.

Jan Tommy Gravdahl - One of the best experts on this subject based on the ideXlab platform.

  • adaptive boarding control system in Surface Effect Ships
    European Control Conference, 2019
    Co-Authors: Vahid Hassani, Oyvind Fidje Auestad, Snorre Fjellvang, Jan Tommy Gravdahl
    Abstract:

    This paper deals with adaptive regulation of wave induced vertical motion on a Surface Effect Ship (SES) at zero speed. To this end, a SES is equipped with variable vent valves, through which cushion pressure can be controlled by adjusting the air out-flow from the cushion. Model scale test and sea trials have shown Effectiveness of such control system. In this paper, we present an adaptive control system which automatically adjust the tuning parameters for the existing SES Motion Control System. A study of the performance of the control system is demonstrated through numerical simulation using a high fidelity model of SES subject to waves.