Optimal Actuator Placement for Real-Time Hybrid Model Testing Using Cable-Driven Parallel Robots

In real-time hybrid model testing, complex ocean structures are emulated by fusing numerical modelling with traditional hydrodynamic model testing. This is done by partitioning the ocean structure under consideration into a numerical and a physical substructure, coupled in real time via a measurement and control interface. The numerically computed load vector is applied to the physical substructure by means of multiple actuated winches so that the resulting experimental platform becomes a type of cable-driven parallel robot. In this context, the placement of the actuated winches is important to ensure that the loads can be accurately and robustly transferred to the physical substructure. This paper addresses this problem by proposing a performance measure and an associated actuator placement procedure that enables accurate force tracking and ensures that the numerically calculated loads can be actuated throughout the testing campaign. To clarify the application of the proposed procedure, it is applied to the design of a test setup for a moored barge. Overall, the paper represents a guideline for robust and beneficial actuator placement for real-time hybrid model testing using cable-driven parallel robots for load-actuation.

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Hybrid Model Tests for Floating Offshore Wind Turbines

ASME 2019 2nd International Offshore Wind Technical Conference ◽

10.1115/iowtc2019-7575 ◽

2019 ◽

Author(s):

Maxime Thys ◽

Alessandro Fontanella ◽

Federico Taruffi ◽

Marco Belloli ◽

Petter Andreas Berthelsen

Keyword(s):

Wind Tunnel ◽

Real Time ◽

Hybrid Model ◽

Wind Turbines ◽

Ocean Basin ◽

Model Testing ◽

Model Tests ◽

Offshore Wind ◽

Offshore Wind Turbines ◽

Floating Offshore Wind Turbines

Abstract Model testing of offshore structures has been standard practice over the years and is often recommended in guidelines and required in certification rules. The standard objectives for model testing are final concept verification, where it is recommended to model the system as closely as possible, and numerical code calibration. Model testing of floating offshore wind turbines is complex due to the response depending on the aero-hydro-servo-elastic system, but also due to difficulties to perform model tests in a hydrodynamic facility with correctly scaled hydrodynamic, aerodynamic and inertial loads. The main limitations are due to the Froude-Reynolds scaling incompatibility, and the wind generation. An approach to solve these issues is by use of hybrid testing where the system is divided in a numerical and a physical substructure, interacting in real-time with each other. Depending on the objectives of the model tests, parts of a physical model of a FOWT can then be placed in a wind tunnel or an ocean basin, where the rest of the system is simulated. In the EU H2020 LIFES50+ project, hybrid model tests were performed in the wind tunnel at Politecnico di Milano, as well as in the ocean basin at SINTEF Ocean. The model tests in the wind tunnel were performed with a physical wind turbine positioned on top of a 6DOF position-controlled actuator, while the hydrodynamic loads and the motions of the support structure were simulated in real-time. For the tests in the ocean basin, a physical floater with tower subject to waves and current was used, while the simulated rotor loads were applied on the model by use of a force actuation system. The tests in both facilities are compared and recommendations on how to combine testing methodologies in an optimal way are discussed.

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Method for Real-Time Hybrid Model Testing of ocean structures: Case study on horizontal mooring systems

Ocean Engineering ◽

10.1016/j.oceaneng.2018.10.042 ◽

2019 ◽

Vol 172 ◽

pp. 46-58 ◽

Cited By ~ 3

Author(s):

S.A. Vilsen ◽

T. Sauder ◽

A.J. Sørensen ◽

M. Føre

Keyword(s):

Real Time ◽

Hybrid Model ◽

Model Testing

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Comparison of Real-Time Hybrid Model Testing of a Braceless Semi-Submersible Wind Turbine and Numerical Simulations

Volume 10: Ocean Renewable Energy ◽

10.1115/omae2017-61121 ◽

2017 ◽

Cited By ~ 2

Author(s):

Madjid Karimirad ◽

Erin E. Bachynski ◽

Petter Andreas Berthelsen ◽

Harald Ormberg

Keyword(s):

Wind Turbine ◽

Real Time ◽

Hybrid Model ◽

Low Frequency ◽

Ocean Basin ◽

Model Testing ◽

Second Order ◽

Experimental Results ◽

Scaled Model ◽

Approximate Methods

In this paper, integrated analyses performed in SIMA are compared against experimental results obtained using real-time hybrid model testing (ReaTHM®) carried out in the ocean basin facilities of MARINTEK in October 2015. The experimental data is from a 1:30 scaled model of a semi-submersible wind turbine. Coupled aero-hydro-servo-elastic simulations are performed in MARINTEK’s SIMA software. The present work extends previous results from Berthelsen et al. [1] by including a blade element/momentum (BEM) model for the rotor forces in SIMA and comparing the coupled responses of the system to the experimental results. The previously presented hydrodynamic model is also further developed, and the importance of second order loads (and applicability of approximate methods for their calculations) is examined. Low-frequency hydrodynamic excitation and damping are seen to be important, but these loads include a combination of viscous and potential forces. For the selected concept, the second order potential flow forces have limited effects on the responses.

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Real-Time Hybrid Model Testing of Moored Floating Structures Using Nonlinear Finite Element Simulations

Dynamics of Coupled Structures, Volume 4 - Conference Proceedings of the Society for Experimental Mechanics Series ◽

10.1007/978-3-319-54930-9_8 ◽

2017 ◽

pp. 79-92 ◽

Cited By ~ 4

Author(s):

Stefan A. Vilsen ◽

Thomas Sauder ◽

Asgeir J. Sørensen

Keyword(s):

Finite Element ◽

Real Time ◽

Hybrid Model ◽

Model Testing ◽

Finite Element Simulations ◽

Nonlinear Finite Element ◽

Floating Structures

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Real-time Hybrid Model Testing of Floating Wind Turbines: Sensitivity to Limited Actuation

Energy Procedia ◽

10.1016/j.egypro.2015.11.400 ◽

2015 ◽

Vol 80 ◽

pp. 2-12 ◽

Cited By ~ 16

Author(s):

Erin E. Bachynski ◽

Valentin Chabaud ◽

Thomas Sauder

Keyword(s):

Real Time ◽

Hybrid Model ◽

Wind Turbines ◽

Model Testing

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Sensitivity Analysis of Limited Actuation for Real-time Hybrid Model Testing of 5MW Bottom-fixed Offshore Wind Turbine

Energy Procedia ◽

10.1016/j.egypro.2017.10.331 ◽

2017 ◽

Vol 137 ◽

pp. 14-25

Author(s):

Madjid Karimirad ◽

Erin E. Bachynski

Keyword(s):

Sensitivity Analysis ◽

Wind Turbine ◽

Real Time ◽

Hybrid Model ◽

Model Testing ◽

Offshore Wind ◽

Offshore Wind Turbine

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Application of PLC and HMI in the measurement and control platform of single-tube heat transfer experiment rig

Advances in Mechanical Engineering ◽

10.1177/1687814020971162 ◽

2020 ◽

Vol 12 (11) ◽

pp. 168781402097116

Author(s):

Wanying Chang ◽

Jing Xie ◽

Jinfeng Wang ◽

Wenqiang Teng ◽

Yuyao Sun ◽

...

Keyword(s):

Heat Transfer ◽

Real Time ◽

Parameter Change ◽

Transfer Experiment ◽

Single Tube ◽

Control Interface ◽

Separate Control ◽

Automatic Acquisition ◽

And Control ◽

Measurement And Control

The single-tube heat transfer experiment rig is composed of various equipment and devices connected through pipelines. This paper adopts Siemens PLC as the main controller and cooperates with WEINVIEW HMI MT6000 series HMI to design the experimental measurement and control platform of a single-tube heat transfer experiment rig. In the single-tube heat transfer experiment measurement and control platform, the PLC communicates with the HMI through an RS-485 cable, and the HMI can display the experimental data changes in real-time and has a separate control interface. The-single tube heat transfer experiment measurement and control platform is safe and reliable, with functions such as real-time monitoring and acquisition, real-time fault alarm, parameter change, and remote control, which simplifies the steps of data acquisition, reduces the difficulty of equipment control, and realizes the automatic acquisition and control.

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Real-Time Hybrid Model Testing of a Semi-Submersible 10MW Floating Wind Turbine and Advances in the Test Method

ASME 2018 1st International Offshore Wind Technical Conference ◽

10.1115/iowtc2018-1081 ◽

2018 ◽

Cited By ~ 2

Author(s):

Maxime Thys ◽

Valentin Chabaud ◽

Thomas Sauder ◽

Lene Eliassen ◽

Lars O. Sæther ◽

...

Keyword(s):

Wind Turbine ◽

Real Time ◽

Physical Model ◽

Hybrid Model ◽

Parallel Robot ◽

Ocean Basin ◽

Model Tests ◽

Test Method ◽

Load Application ◽

Floating Wind Turbine

This article presents the Real-Time Hybrid Model (ReaTHM®) tests that were performed on a 10-MW semi-submersible floating wind turbine in the Ocean Basin at SINTEF Ocean in March 2018. The ReaTHM test method was used for the model tests to circumvent the limitations encountered when performing model tests with wind and waves. The physical model was subject to physical waves, while the rotor and tower loads were simulated in real-time and applied on the model by use of a cable-driven parallel robot. Recent advances in the ReaTHM test method allowed for extended testing possibilities and load application up to the 3p frequency and the first tower bending frequency.

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Force Actuated Real-Time Hybrid Model Testing of a Moored Vessel: A Case Study Investigating Force Errors

IFAC-PapersOnLine ◽

10.1016/j.ifacol.2018.09.472 ◽

2018 ◽

Vol 51 (29) ◽

pp. 74-79

Author(s):

Einar S. Ueland ◽

Roger Skjetne ◽

Stefan A. Vilsen

Keyword(s):

Real Time ◽

Hybrid Model ◽

Model Testing

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Real-Time Hybrid Model Testing of a Braceless Semi-Submersible Wind Turbine: Part I — The Hybrid Approach

Volume 6: Ocean Space Utilization; Ocean Renewable Energy ◽

10.1115/omae2016-54435 ◽

2016 ◽

Cited By ~ 19

Author(s):

Thomas Sauder ◽

Valentin Chabaud ◽

Maxime Thys ◽

Erin E. Bachynski ◽

Lars Ove Sæther

Keyword(s):

Wind Turbine ◽

Real Time ◽

Physical Model ◽

Hybrid Model ◽

Hybrid Approach ◽

Physical Modelling ◽

Short Review ◽

Ocean Basin ◽

Model Testing ◽

Aerodynamic Load

This article presents a method for performing Real-Time Hybrid Model testing (ReaTHM testing) of a floating wind turbine (FWT). The advantage of this method compared to the physical modelling of the wind in an ocean basin, is that it solves the Froude-Reynolds scaling conflict, which is a key issue in FWT testing. ReaTHM testing allows for more accurate testing also in transient conditions, or degraded conditions, which are not feasible yet with physical wind. The originality of the presented method lies in the fact that all aerodynamic load components of importance for the structure were identified and applied on the physical model, while in previous similar projects, only the aerodynamic thrust force was applied on the physical model. The way of applying the loads is also new. The article starts with a short review (mostly references) of ReaTHM testing when applied to other fields than marine technology. It then describes the design of the hybrid setup, its qualification, and discusses possible error sources and their quantification. The second part of the article [1] focuses on the performance of a braceless semi-submersible FWT, tested with the developed method. The third part [2] describes how the experimental data was used to calibrate a numerical model of the FWT.

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