The Experts below are selected from a list of 5274 Experts worldwide ranked by ideXlab platform
ThorI I Fossen - One of the best experts on this subject based on the ideXlab platform.
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NONLINEAR MODEL IDENTIFICATION OF A MARINE Propeller OVER FOUR-QUADRANT OPERATIONS
IFAC Proceedings Volumes, 2016Co-Authors: Luca Pivano, ThorI I Fossen, Tor Arne JohansenAbstract:Abstract This paper proposes a nonlinear dynamics model for a marine Propeller able to reproduce the Propeller Thrust over the full four-quadrant range of Propeller shaft speed and vessel speed. A two-state model has been identified from experimental data. The model includes a state equation for the Propeller shaft speed and one that describes the dynamics of the axial flow velocity. The model reproduces accurately Propeller Thrust and torque over a wide range of operation.
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Experimental Validation of a Marine Propeller Thrust Estimation Scheme
Modeling Identification and Control: A Norwegian Research Bulletin, 2007Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:A Thrust estimation scheme for a marine Propeller has been experimentally tested in waves and with a device that simulates the influence of a vessel hull. The scheme is formed by a nonlinear Propeller torque observer and a mapping to generate the Thrust from the observed torque. The mapping includes the estimation of the advance number. This is utilized to improve the performance when the Propeller is lightly loaded. The advance speed is assumed to be unknown, and only measurements of shaft speed and motor torque have been used. Accurate results have been obtained in experimental tests.
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ACC - Nonlinear Thrust Controller for Marine Propellers in Four-Quadrant Operations
2007 American Control Conference, 2007Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:In this paper a nonlinear Thrust controller for a marine Propeller in four-quadrant operations is presented. It is a shaft speed controller where the desired velocity is computed based on the desired Propeller Thrust and on the torque losses, estimated with a nonlinear observer. Experimental results are provided to demonstrate the effectiveness of the controller. The proposed scheme shows improved performance in Thrust production when compared to traditional shaft speed and torque control.
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CDC - Marine Propeller Thrust Estimation in Four-Quadrant Operations
Proceedings of the 45th IEEE Conference on Decision and Control, 2006Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:This paper proposes a scheme for Thrust estimation of a marine Propeller over the full four-quadrant range of Propeller shaft speed and vessel speed. Based on Shaft speed and motor torque measurements, the scheme involves a nonlinear observer for the Propeller torque that shows stability and robustness for bounded modeling and measurement errors. The Propeller Thrust is computed as a static function of the Propeller torque. The performance has been demonstrated in e perimental tests.
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Marine Propeller Thrust Estimation in Four-Quadrant Operations
Proceedings of the 45th IEEE Conference on Decision and Control, 2006Co-Authors: Luca Pivano, Tor Anders Johansen, Øyvind N. Smogeli, ThorI I FossenAbstract:This paper proposes a scheme for Thrust estimation of a marine Propeller over the full four-quadrant range of Propeller shaft speed and vessel speed. Based on shaft speed and motor torque measurements, the scheme involves a nonlinear observer for the Propeller torque that shows stability and robustness for hounded modeling and measurement errors. The Propeller Thrust is computed as a static function of the Propeller torque. The performance has been demonstrated in experimental tests
Luca Pivano - One of the best experts on this subject based on the ideXlab platform.
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NONLINEAR MODEL IDENTIFICATION OF A MARINE Propeller OVER FOUR-QUADRANT OPERATIONS
IFAC Proceedings Volumes, 2016Co-Authors: Luca Pivano, ThorI I Fossen, Tor Arne JohansenAbstract:Abstract This paper proposes a nonlinear dynamics model for a marine Propeller able to reproduce the Propeller Thrust over the full four-quadrant range of Propeller shaft speed and vessel speed. A two-state model has been identified from experimental data. The model includes a state equation for the Propeller shaft speed and one that describes the dynamics of the axial flow velocity. The model reproduces accurately Propeller Thrust and torque over a wide range of operation.
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Experimental Validation of a Marine Propeller Thrust Estimation Scheme
Modeling Identification and Control: A Norwegian Research Bulletin, 2007Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:A Thrust estimation scheme for a marine Propeller has been experimentally tested in waves and with a device that simulates the influence of a vessel hull. The scheme is formed by a nonlinear Propeller torque observer and a mapping to generate the Thrust from the observed torque. The mapping includes the estimation of the advance number. This is utilized to improve the performance when the Propeller is lightly loaded. The advance speed is assumed to be unknown, and only measurements of shaft speed and motor torque have been used. Accurate results have been obtained in experimental tests.
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ACC - Nonlinear Thrust Controller for Marine Propellers in Four-Quadrant Operations
2007 American Control Conference, 2007Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:In this paper a nonlinear Thrust controller for a marine Propeller in four-quadrant operations is presented. It is a shaft speed controller where the desired velocity is computed based on the desired Propeller Thrust and on the torque losses, estimated with a nonlinear observer. Experimental results are provided to demonstrate the effectiveness of the controller. The proposed scheme shows improved performance in Thrust production when compared to traditional shaft speed and torque control.
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CDC - Marine Propeller Thrust Estimation in Four-Quadrant Operations
Proceedings of the 45th IEEE Conference on Decision and Control, 2006Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:This paper proposes a scheme for Thrust estimation of a marine Propeller over the full four-quadrant range of Propeller shaft speed and vessel speed. Based on Shaft speed and motor torque measurements, the scheme involves a nonlinear observer for the Propeller torque that shows stability and robustness for bounded modeling and measurement errors. The Propeller Thrust is computed as a static function of the Propeller torque. The performance has been demonstrated in e perimental tests.
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Marine Propeller Thrust Estimation in Four-Quadrant Operations
Proceedings of the 45th IEEE Conference on Decision and Control, 2006Co-Authors: Luca Pivano, Tor Anders Johansen, Øyvind N. Smogeli, ThorI I FossenAbstract:This paper proposes a scheme for Thrust estimation of a marine Propeller over the full four-quadrant range of Propeller shaft speed and vessel speed. Based on shaft speed and motor torque measurements, the scheme involves a nonlinear observer for the Propeller torque that shows stability and robustness for hounded modeling and measurement errors. The Propeller Thrust is computed as a static function of the Propeller torque. The performance has been demonstrated in experimental tests
Stephen R. Turnock - One of the best experts on this subject based on the ideXlab platform.
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A Propeller Thrust and torque dynamometer for wind tunnel models
Strain, 2002Co-Authors: A. G. Molland, Stephen R. TurnockAbstract:The design, construction and calibration of a Propeller Thrust and torque dynamometer is described. The dynamometer was constructed primarily for the testing of model ship Propellers when working upstream of a rudder. An outline of the specialised design requirements is given. The basic design concepts are described together with the reasons for the choice of flexures and their dimensions, strain gauges, circuits, bridge voltages and instrumentation. A brief description of the calibration process is given and the calibration results are described and discussed. It was found that there were no interactions between the components, a satisfactory overall measuring accuracy was achieved and the dynamometer had performed well in service. It is concluded that the overall design approach, concept and design details were satisfactory and suitable for this particular application.
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Flow straightening effects on a ship rudder due to upstream Propeller and hull
International Shipbuilding Progress, 2002Co-Authors: A. G. Molland, Stephen R. TurnockAbstract:A description is given of an investigation into the flow straightening effects on a ship rudder of an upstram Propeller and hull. In order to quantify these effects an experimental investigation was carried out using a 3.5 m x 2.5 m wind tunnel. The tests were carried out with an all-movable rudder and a representative Propeller for drift angles up to ±15°. Three different lengths of centreboards were tested upstream of the rudder-Propeller combination, together with a representative hull. Flow straightening effects were found to be dependent on the type of upstream body, drift angle and Propeller Thrust loading. The effects of the three centreboards upstream of the Propeller were found to be significantly greater than the effect of the Propeller on its own. The straightening effects of the hull were found to be less than those for the centreline boards. There was an increase in flow straightening with increase in Propeller Thrust loading at a drift angle of 15° but at 7.5° drift this effect was less apparent and sometimes reversed. The overall results provide a better understanding of flow straightening effects and data for improving the prediction of manoeuvring rudder forces. The data for the centreline boards are likely to have applications for vessels with a relatively thin upstream skeg, whilst the data for the rudder plus Propeller combination in isolation should be suitable for vessels with open water sterns, such as twin screw vessels.
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Influence of Propeller loading on ship rudder performance
1992Co-Authors: A. G. Molland, Stephen R. TurnockAbstract:The results of wind tunnel experiments on typical ship rudders and Propeller combinations are presented. The experiments simulated the condition of a rudder operating aft of a Propeller but without the influence of the hull. Three rudder types were tested, a semi-balanced skeg rudder 'th taper ratio 0.8 and all movable rudders with taper ratios of 0.8 and 1.0. The Propeller was modelled on a Wageningen B4.40. The longitudinal separation of rudder and Propeller was varied, and by extending the span of the rectangular rudder an insight into the influence of Propeller diameter/rudder span was provided. Results are presented for each rudder as lift and drag coefficients and centre of pressure for selected angles of attack and changes in Propeller Thrust loading. Surface pressure distributions over the rudder were also obtained in order to provide a detailed knowledge of the distribution of forces over the rudder. The results demonstrate the controlling influence of Propeller Thrust loading on basic rudder forces and on the movement of rudder centre of pressure. The changes in stall characteristics and stall angle due to Propeller action were also identified. The results provide force data for use in manoeuvring calculations and detailed data for- the validation of numerical modelling of the interaction problem.
Øyvind N. Smogeli - One of the best experts on this subject based on the ideXlab platform.
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Experimental Validation of a Marine Propeller Thrust Estimation Scheme
Modeling Identification and Control: A Norwegian Research Bulletin, 2007Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:A Thrust estimation scheme for a marine Propeller has been experimentally tested in waves and with a device that simulates the influence of a vessel hull. The scheme is formed by a nonlinear Propeller torque observer and a mapping to generate the Thrust from the observed torque. The mapping includes the estimation of the advance number. This is utilized to improve the performance when the Propeller is lightly loaded. The advance speed is assumed to be unknown, and only measurements of shaft speed and motor torque have been used. Accurate results have been obtained in experimental tests.
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ACC - Nonlinear Thrust Controller for Marine Propellers in Four-Quadrant Operations
2007 American Control Conference, 2007Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:In this paper a nonlinear Thrust controller for a marine Propeller in four-quadrant operations is presented. It is a shaft speed controller where the desired velocity is computed based on the desired Propeller Thrust and on the torque losses, estimated with a nonlinear observer. Experimental results are provided to demonstrate the effectiveness of the controller. The proposed scheme shows improved performance in Thrust production when compared to traditional shaft speed and torque control.
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CDC - Marine Propeller Thrust Estimation in Four-Quadrant Operations
Proceedings of the 45th IEEE Conference on Decision and Control, 2006Co-Authors: Luca Pivano, Øyvind N. Smogeli, Tor Arne Johansen, ThorI I FossenAbstract:This paper proposes a scheme for Thrust estimation of a marine Propeller over the full four-quadrant range of Propeller shaft speed and vessel speed. Based on Shaft speed and motor torque measurements, the scheme involves a nonlinear observer for the Propeller torque that shows stability and robustness for bounded modeling and measurement errors. The Propeller Thrust is computed as a static function of the Propeller torque. The performance has been demonstrated in e perimental tests.
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Marine Propeller Thrust Estimation in Four-Quadrant Operations
Proceedings of the 45th IEEE Conference on Decision and Control, 2006Co-Authors: Luca Pivano, Tor Anders Johansen, Øyvind N. Smogeli, ThorI I FossenAbstract:This paper proposes a scheme for Thrust estimation of a marine Propeller over the full four-quadrant range of Propeller shaft speed and vessel speed. Based on shaft speed and motor torque measurements, the scheme involves a nonlinear observer for the Propeller torque that shows stability and robustness for hounded modeling and measurement errors. The Propeller Thrust is computed as a static function of the Propeller torque. The performance has been demonstrated in experimental tests
A. G. Molland - One of the best experts on this subject based on the ideXlab platform.
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A Propeller Thrust and torque dynamometer for wind tunnel models
Strain, 2002Co-Authors: A. G. Molland, Stephen R. TurnockAbstract:The design, construction and calibration of a Propeller Thrust and torque dynamometer is described. The dynamometer was constructed primarily for the testing of model ship Propellers when working upstream of a rudder. An outline of the specialised design requirements is given. The basic design concepts are described together with the reasons for the choice of flexures and their dimensions, strain gauges, circuits, bridge voltages and instrumentation. A brief description of the calibration process is given and the calibration results are described and discussed. It was found that there were no interactions between the components, a satisfactory overall measuring accuracy was achieved and the dynamometer had performed well in service. It is concluded that the overall design approach, concept and design details were satisfactory and suitable for this particular application.
-
Flow straightening effects on a ship rudder due to upstream Propeller and hull
International Shipbuilding Progress, 2002Co-Authors: A. G. Molland, Stephen R. TurnockAbstract:A description is given of an investigation into the flow straightening effects on a ship rudder of an upstram Propeller and hull. In order to quantify these effects an experimental investigation was carried out using a 3.5 m x 2.5 m wind tunnel. The tests were carried out with an all-movable rudder and a representative Propeller for drift angles up to ±15°. Three different lengths of centreboards were tested upstream of the rudder-Propeller combination, together with a representative hull. Flow straightening effects were found to be dependent on the type of upstream body, drift angle and Propeller Thrust loading. The effects of the three centreboards upstream of the Propeller were found to be significantly greater than the effect of the Propeller on its own. The straightening effects of the hull were found to be less than those for the centreline boards. There was an increase in flow straightening with increase in Propeller Thrust loading at a drift angle of 15° but at 7.5° drift this effect was less apparent and sometimes reversed. The overall results provide a better understanding of flow straightening effects and data for improving the prediction of manoeuvring rudder forces. The data for the centreline boards are likely to have applications for vessels with a relatively thin upstream skeg, whilst the data for the rudder plus Propeller combination in isolation should be suitable for vessels with open water sterns, such as twin screw vessels.
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Influence of Propeller loading on ship rudder performance
1992Co-Authors: A. G. Molland, Stephen R. TurnockAbstract:The results of wind tunnel experiments on typical ship rudders and Propeller combinations are presented. The experiments simulated the condition of a rudder operating aft of a Propeller but without the influence of the hull. Three rudder types were tested, a semi-balanced skeg rudder 'th taper ratio 0.8 and all movable rudders with taper ratios of 0.8 and 1.0. The Propeller was modelled on a Wageningen B4.40. The longitudinal separation of rudder and Propeller was varied, and by extending the span of the rectangular rudder an insight into the influence of Propeller diameter/rudder span was provided. Results are presented for each rudder as lift and drag coefficients and centre of pressure for selected angles of attack and changes in Propeller Thrust loading. Surface pressure distributions over the rudder were also obtained in order to provide a detailed knowledge of the distribution of forces over the rudder. The results demonstrate the controlling influence of Propeller Thrust loading on basic rudder forces and on the movement of rudder centre of pressure. The changes in stall characteristics and stall angle due to Propeller action were also identified. The results provide force data for use in manoeuvring calculations and detailed data for- the validation of numerical modelling of the interaction problem.
