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5 pages, 191 KiB

Open AccessEditorial

Measurement Methods in the Operation of Ships and Offshore Facilities

by Leszek Chybowski, Arkadiusz Tomczak and Maciej Kozak

Sensors 2021, 21(6), 2159; https://doi.org/10.3390/s21062159 - 19 Mar 2021

Cited by 2 | Viewed by 1381

Abstract

The development of modern measurement methods for ship systems has occurred due to economic changes and increasingly stringent environmental requirements [...] Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

Research

Jump to: Editorial

13 pages, 3507 KiB

Open AccessArticle

Assessment of the Propulsion System Operation of the Ships Equipped with the Air Lubrication System

by Mariusz Giernalczyk and Piotr Kaminski

Sensors 2021, 21(4), 1357; https://doi.org/10.3390/s21041357 - 14 Feb 2021

Cited by 9 | Viewed by 4578

Abstract

This paper is an attempt to evaluate the effectiveness of the ship’s hull air lubrication system in order to reduce the drag leading to fuel consumption reduction by ships. The available papers and reports were analyzed, in which records of the operation parameters [...] Read more.

This paper is an attempt to evaluate the effectiveness of the ship’s hull air lubrication system in order to reduce the drag leading to fuel consumption reduction by ships. The available papers and reports were analyzed, in which records of the operation parameters of the propulsion system of ships equipped with this system were presented. These reports clearly show the advantages of using air lubrication system. On the basis of collected operating parameters of the propulsion system the authors performed analysis of operation effectiveness of the Air Lubrication System on the modern passenger ship was. The results of this analysis do not allow for a clearly positive opinion about its effectiveness. Additionally, the conditions that should be met for the system to be more effective and to significantly increase the propulsion efficiency were indicated. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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18 pages, 10278 KiB

Open AccessArticle

Application of Measurement Sensors and Navigation Devices in Experimental Research of the Computer System for the Control of an Unmanned Ship Model

by Tadeusz Szelangiewicz, Katarzyna Żelazny, Andrzej Antosik and Maciej Szelangiewicz

Sensors 2021, 21(4), 1312; https://doi.org/10.3390/s21041312 - 12 Feb 2021

Cited by 10 | Viewed by 3018

Abstract

Unmanned autonomous transport vessels (MASS) are the future of maritime transport. The most important task in the design and construction of unmanned ships is to develop algorithms and a computer program for autonomous control. In order for such a computer program to properly [...] Read more.

Unmanned autonomous transport vessels (MASS) are the future of maritime transport. The most important task in the design and construction of unmanned ships is to develop algorithms and a computer program for autonomous control. In order for such a computer program to properly control the ship (realizing various functions), the ship must be equipped with a computer system as well as measurement sensors and navigation devices, from which the recorded parameters are processed and used for autonomous control of the ship. Within the framework of conducted research on autonomous ships, an experimental model of an unmanned ship was built. This model was equipped with a propulsion system not commonly used on transport vessels (two azimuth stern thrusters and two bow tunnel thrusters), but providing excellent propulsion and steering characteristics. A complete computer system with the necessary measuring sensors and navigation devices has also been installed in the model of the ship, which enables it to perform all functions during autonomous control. The objective of the current research was to design and build a prototype computer system with the necessary measurement sensors and navigation devices with which to autonomously control the unmanned ship model. The designed computer system is expected to be optimal for planned tasks during control software tests. Tests carried out on open waters confirmed the correctness of the operation of the computer system and the entire measurement and navigation equipment of the built model of the unmanned transport vessel. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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15 pages, 5968 KiB

Open AccessArticle

Spectral Analysis of Torsional Vibrations Measured by Optical Sensors, as a Method for Diagnosing Injector Nozzle Coking in Marine Diesel Engines

by Sebastian Drewing and Kazimierz Witkowski

Sensors 2021, 21(3), 775; https://doi.org/10.3390/s21030775 - 24 Jan 2021

Cited by 6 | Viewed by 2503

Abstract

The study aimed to verify whether it is possible to diagnose the coking of a marine diesel engine injector nozzle by performing a spectral analysis of the crankshaft’s torsional vibrations. The measurements were taken using laser heads, clocked at 16 MHz. The reasons [...] Read more.

The study aimed to verify whether it is possible to diagnose the coking of a marine diesel engine injector nozzle by performing a spectral analysis of the crankshaft’s torsional vibrations. The measurements were taken using laser heads, clocked at 16 MHz. The reasons for selecting this type of optical sensors are described as well. The tests were carried out under laboratory conditions, using a test stand with a Sulzer 3AL 25/3 engine, operating under a load created by a Domel GD8 500–50/3 electric generator. A unique method is presented in the paper, which enables the measuring and calculation of torsional vibrations of engine crankshafts. The method was developed at the Chair of Marine Power Plants at the Maritime University of Gdynia. It has been proven that the distribution of differences in the values of individual harmonic components depends on the location of a defective injector nozzle in the cylinder. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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15 pages, 3419 KiB

Open AccessArticle

Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials

by Lesław Kyzioł, Katarzyna Panasiuk, Grzegorz Hajdukiewicz and Krzysztof Dudzik

Sensors 2021, 21(1), 145; https://doi.org/10.3390/s21010145 - 28 Dec 2020

Cited by 12 | Viewed by 2549

Abstract

Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). [...] Read more.

Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). Modern measurement methods and tools allow to determine the properties of the composite material, already during its design. The article presents the use of the method of acoustic emission and Kolmogorov-Sinai (K-S) metric entropy to determine the mechanical properties of composites. The tested materials were polyester-glass laminate without additives and with a 10% content of polyester-glass waste. The changes taking place in the composite material during loading were visualized using a piezoelectric sensor used in the acoustic emission method. Thanks to the analysis of the RMS parameter (root mean square of the acoustic emission signal), it is possible to determine the range of stresses at which significant changes occur in the material in terms of its use as a construction material. In the K-S entropy method, an important measuring tool is the extensometer, namely the displacement sensor built into it. The results obtained during the static tensile test with the use of an extensometer allow them to be used to calculate the K-S metric entropy. Many materials, including composite materials, do not have a yield point. In principle, there are no methods for determining the transition of a material from elastic to plastic phase. The authors showed that, with the use of a modern testing machine and very high-quality instrumentation to record measurement data using the Kolmogorov-Sinai (K-S) metric entropy method and the acoustic emission (AE) method, it is possible to determine the material transition from elastic to plastic phase. Determining the yield strength of composite materials is extremely important information when designing a structure. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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16 pages, 6809 KiB

Open AccessArticle

Identification of Gate Turn-Off Thyristor Switching Patterns Using Acoustic Emission Sensors

by Maciej Kozak, Artur Bejger and Arkadiusz Tomczak

Sensors 2021, 21(1), 70; https://doi.org/10.3390/s21010070 - 24 Dec 2020

Cited by 6 | Viewed by 2377

Abstract

Modern seagoing ships are often equipped with converters which utilize semiconductor power electronics devices like thyristors or power transistors. Most of them are used in driving applications such as powerful main propulsion plants, auxiliary podded drives and thrusters. When it comes to main [...] Read more.

Modern seagoing ships are often equipped with converters which utilize semiconductor power electronics devices like thyristors or power transistors. Most of them are used in driving applications such as powerful main propulsion plants, auxiliary podded drives and thrusters. When it comes to main propulsion drives the power gets seriously high, thus the need for use of medium voltage power electronics devices arises. As it turns out, power electronic parts are the most susceptible to faults or failures in the whole electric drive system. These devices require efficient cooling, so manufacturers design housings in a way that best dissipates heat from the inside of the chips to the metal housing. This results in susceptibility to damage due to the heterogeneity of combined materials and the difference in temperature expansion of elements inside the power device. Currently used methods of prediction of damage and wear of semiconductor elements are limited to measurements of electrical quantities generated by devices during operation and not quite effective in case of early-stage damage to semiconductor layers. The article presents an introduction and preliminary tests of a method utilizing an acoustic emission sensor which can be used in detecting early stage damages of the gate turn-off thyristor. Theoretical considerations and chosen experimental results of initial measurements of acoustic emission signals of the medium voltage gate turn-off thyristor are presented. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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16 pages, 4891 KiB

Open AccessArticle

An Ensemble-Based Approach to Anomaly Detection in Marine Engine Sensor Streams for Efficient Condition Monitoring and Analysis

by Donghyun Kim, Sangbong Lee and Jihwan Lee

Sensors 2020, 20(24), 7285; https://doi.org/10.3390/s20247285 - 18 Dec 2020

Cited by 15 | Viewed by 3182

Abstract

This study proposes an unsupervised anomaly detection method using sensor streams from the marine engine to detect the anomalous system behavior, which may be a possible sign of system failure. Previous works on marine engine anomaly detection proposed a clustering-based or statistical control [...] Read more.

This study proposes an unsupervised anomaly detection method using sensor streams from the marine engine to detect the anomalous system behavior, which may be a possible sign of system failure. Previous works on marine engine anomaly detection proposed a clustering-based or statistical control chart-based approach that is unstable according to the choice of hyperparameters, or cannot fit well to the high-dimensional dataset. As a remedy to this limitation, this study adopts an ensemble-based approach to anomaly detection. The idea is to train several anomaly detectors with varying hyperparameters in parallel and then combine its result in the anomaly detection phase. Because the anomaly is detected by the combination of different detectors, it is robust to the choice of hyperparameters without loss of accuracy. To demonstrate our methodology, an actual dataset obtained from a 200,000-ton cargo vessel from a Korean shipping company that uses two-stroke diesel engine is analyzed. As a result, anomalies were successfully detected from the high-dimensional and large-scale dataset. After detecting the anomaly, clustering analysis was conducted to the anomalous observation to examine anomaly patterns. By investigating each cluster’s feature distribution, several common patterns of abnormal behavior were successfully visualized. Although we analyzed the data from two-stroke diesel engine, our method can be applied to various types of marine engine. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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21 pages, 9088 KiB

Open AccessArticle

Marine Diesel Engine Exhaust Emissions Measured in Ship’s Dynamic Operating Conditions

by Artur Bogdanowicz and Tomasz Kniaziewicz

Sensors 2020, 20(22), 6589; https://doi.org/10.3390/s20226589 - 18 Nov 2020

Cited by 10 | Viewed by 3453

Abstract

The paper presents the results of research on measuring the emissions from marine diesel engines in dynamic states. The problem is as follows: How to measure emissions of the composition of exhaust gases on board a ship, without direct measurement of fuel consumption [...] Read more.

The paper presents the results of research on measuring the emissions from marine diesel engines in dynamic states. The problem is as follows: How to measure emissions of the composition of exhaust gases on board a ship, without direct measurement of fuel consumption and an air flow to marine diesel engine, during maneuvering the ship in the port area. The authors proposed a measurement methodology using an exhaust gas analyzer with simultaneous recording of the load indicator, engine speed, inclinometer, and Global Positioning System (GPS) data. Fuel consumption was calculated based on mean indicated pressure (MIP) tests. Recorded data were processed in the LabView systems engineering software. A simple neural network algorithm was used to model the concentrations of ingredients contained in engine exhaust gases during dynamic states. Using the recorded data, it is possible to calculate the emissions of the composition of exhaust gases from the marine diesel engine and calculate the route emissions of the tested vessel. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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27 pages, 21275 KiB

Open AccessArticle

Dimensioning Method of Floating Offshore Objects by Means of Quasi-Similarity Transformation with Reduced Tolerance Errors

by Grzegorz Stępień, Arkadiusz Tomczak, Martin Loosaar and Tomasz Ziębka

Sensors 2020, 20(22), 6497; https://doi.org/10.3390/s20226497 - 13 Nov 2020

Cited by 6 | Viewed by 2064

Abstract

The human activities in the offshore oil and gas, renewable energy and construction industry require reliable data acquired by different types of hydrographic sensors: DGNSS (Differential Global Navigation Satellite System) positioning, attitude sensors, multibeam sonars, lidars or total stations installed on the offshore [...] Read more.

The human activities in the offshore oil and gas, renewable energy and construction industry require reliable data acquired by different types of hydrographic sensors: DGNSS (Differential Global Navigation Satellite System) positioning, attitude sensors, multibeam sonars, lidars or total stations installed on the offshore vessel, drones or platforms. Each component or sensor that produces information, unique to its position, will have a point that is considered as the reference point of that sensor. The accurate measurement of the offsets is vital to establish the mathematical relation between sensor and vessel common reference point in order to achieve sufficient accuracy of the survey data. If possible, the vessel will be put on a hard stand so that it can be very accurately measured using the standard land survey technique. However, due to the complex environment and sensors being mobilized when the vessel is in service, this may not be possible, and the offsets will have to be measured in sea dynamic conditions by means of a total station from a floating platform. This article presents the method of transformation by similarity with elements of affine transformation, called Q-ST (Quasi-Similarity Transformation). The Q-ST has been designed for measurements on such unstable substrates when it is not possible to level the total station (when the number of adjustment points is small (4–6 points)). Such situation occurs, among others, when measuring before the offshore duties or during the jack up or semi-submersible rig move. The presented calculation model is characterized by zero deviations at the adjustment points (at four common points). The transformation concerns the conversion of points between two orthogonal and inclined reference frames. The method enables the independent calculation of the scale factor, rotation matrix and system translation. Scaling is performed first in real space, and then both systems are shifted to the centroid, which is the center of gravity. The center of gravity is determined for the fit points that meet the criterion of stability of the orthogonal transformation. Then, the rotation matrix is computed, and a translation is performed from the computational (centroid) to real space. In the applied approach, the transformation parameters, scaling, rotation and translation, are determined independently, and the least squares method is applied independently at each stage of the calculations. The method has been verified in laboratory conditions as well as in real conditions. The results were compared to other known methods of coordinate transformation. The proposed approach is a development of the idea of transformation by similarity based on centroids. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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17 pages, 4825 KiB

Open AccessArticle

Analysis of the Dynamic Height Distribution at the Estuary of the Odra River Based on Gravimetric Measurements Acquired with the Use of a Light Survey Boat—A Case Study

by Krzysztof Pyrchla, Arkadiusz Tomczak, Grzegorz Zaniewicz, Jerzy Pyrchla and Paulina Kowalska

Sensors 2020, 20(21), 6044; https://doi.org/10.3390/s20216044 - 23 Oct 2020

Cited by 4 | Viewed by 1956

Abstract

This article presents possible applications of a dynamic gravity meter (MGS-6, Micro-g LaCoste) for determining the dynamic height along the Odra River, in northwest Poland. The gravity measurement campaign described in this article was conducted on a small, hybrid-powered survey vessel (overall length: [...] Read more.

This article presents possible applications of a dynamic gravity meter (MGS-6, Micro-g LaCoste) for determining the dynamic height along the Odra River, in northwest Poland. The gravity measurement campaign described in this article was conducted on a small, hybrid-powered survey vessel (overall length: 9.5 m). We discuss a method for processing the results of gravimetric measurements performed on a mobile platform affected by strong external disturbances. Because measurement noise in most cases consists of signals caused by non-ideal observation conditions, careful attempts were made to analyze and eliminate the noise. Two different data processing strategies were implemented, one for a 20 Hz gravity data stream and another for a 1 Hz data stream. A comparison of the achieved results is presented. A height reference level, consistent for the entire estuary, is critical for the construction of a safe waterway system, including 3D navigation with the dynamic estimation of under-keel clearance on the Odra and other Polish rivers. The campaign was conducted in an area where the accuracy of measurements (levelling and gravimetric) is of key importance for shipping safety. The shores in the presented area of interest are swampy, so watercraft-based measurements are preferred. The method described in the article can be successfully applied to measurements in all near-zero-depth areas. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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24 pages, 10121 KiB

Open AccessArticle

The Effect of Deflections and Elastic Deformations on Geometrical Deviation and Shape Profile Measurements of Large Crankshafts with Uncontrolled Supports

by Krzysztof Nozdrzykowski, Stanisław Adamczak, Zenon Grządziel and Paweł Dunaj

Sensors 2020, 20(19), 5714; https://doi.org/10.3390/s20195714 - 08 Oct 2020

Cited by 10 | Viewed by 2470

Abstract

This article presents a multi-criteria analysis of the errors that may occur while measuring the geometric deviations of crankshafts that require multi-point support. The analysis included in the paper confirmed that the currently used conventional support method—in which the journals of large crankshafts [...] Read more.

This article presents a multi-criteria analysis of the errors that may occur while measuring the geometric deviations of crankshafts that require multi-point support. The analysis included in the paper confirmed that the currently used conventional support method—in which the journals of large crankshafts rest on a set of fixed rigid vee-blocks—significantly limits the detectability of their geometric deviations, especially those of the main journal axes’ positions. Insights for performing practical measurements, which will improve measurement procedures and increase measurement accuracy, are provided. The results are presented both graphically and as discrete amplitude spectra to make a visual, qualitative comparison, which is complemented by a quantitative assessment based on correlation analysis. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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16 pages, 21448 KiB

Open AccessArticle

An Attitude Prediction Method for Autonomous Recovery Operation of Unmanned Surface Vehicle

by Yang Yang, Ping Pan, Xingang Jiang, Shuanghua Zheng, Yongjian Zhao, Yi Yang, Songyi Zhong and Yan Peng

Sensors 2020, 20(19), 5662; https://doi.org/10.3390/s20195662 - 03 Oct 2020

Cited by 3 | Viewed by 2645

Abstract

The development of launch and recovery technology is key for the application to the unmanned surface vehicle (USV). Also, a launch and recovery system (L&RS) based on a pneumatic ejection mechanism has been developed in our previous study. To improve the launch accuracy [...] Read more.

The development of launch and recovery technology is key for the application to the unmanned surface vehicle (USV). Also, a launch and recovery system (L&RS) based on a pneumatic ejection mechanism has been developed in our previous study. To improve the launch accuracy and reduce the influence of the sea waves, we propose a stacking model of one-dimensional convolutional neural network and long short-term memory neural network predicting the attitude of the USV. The data from experiments by “Jinghai VII” USV developed by Shanghai University, China, under levels 1–4 sea conditions are used to train and test the network. The results show that the stabilized platform with the proposed prediction method can keep the launching angle of the launching mechanism constant by regulating the pitching joint and rotation joint under the random influence from the wave. Finally, the efficiency and effectiveness of the L&RS are demonstrated by the successful application in actual environments. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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18 pages, 7465 KiB

Open AccessArticle

Remanufacturing System with Chatter Suppression for CNC Turning

by Karol Miądlicki, Marcin Jasiewicz, Marcin Gołaszewski, Marcin Królikowski and Bartosz Powałka

Sensors 2020, 20(18), 5070; https://doi.org/10.3390/s20185070 - 07 Sep 2020

Cited by 6 | Viewed by 2188

Abstract

The paper presents the concept of a support system for the manufacture of machine spare parts. The operation of the system is based on a reverse engineering module enabling feature recognition based on a 3D parts scan. Then, a CAD geometrical model is [...] Read more.

The paper presents the concept of a support system for the manufacture of machine spare parts. The operation of the system is based on a reverse engineering module enabling feature recognition based on a 3D parts scan. Then, a CAD geometrical model is generated, on the basis of which a machining strategy using the CAM system is developed. In parallel, based on the geometric model, a finite element model is built, which facilitates defining technological parameters, allowing one to minimize the risk of vibrations during machining. These parameters constitute input information to the CAM module. The operation of the described system is presented on the example of machining parts of the shaft class. The result is a replacement part, the accuracy of which was compared by means of the iterative closest point algorithm obtaining the RMSE at the level of scanner accuracy. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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21 pages, 6971 KiB

Open AccessArticle

Full-Scale Maneuvering Trials Correction and Motion Modelling Based on Actual Sea and Weather Conditions

by Bin Mei, Licheng Sun and Guoyou Shi

Sensors 2020, 20(14), 3963; https://doi.org/10.3390/s20143963 - 16 Jul 2020

Cited by 4 | Viewed by 2460

Abstract

Aiming at the poor accuracy and difficult verification of maneuver modeling induced by the wind, waves and sea surface currents in the actual sea, a novel sea trials correction method for ship maneuvering is proposed. The wind and wave drift forces are calculated [...] Read more.

Aiming at the poor accuracy and difficult verification of maneuver modeling induced by the wind, waves and sea surface currents in the actual sea, a novel sea trials correction method for ship maneuvering is proposed. The wind and wave drift forces are calculated according to the measurement data. Based on the steady turning hypothesis and pattern search algorithm, the adjustment parameters of wind, wave and sea surface currents were solved, the drift distances and drift velocities of wind, waves and sea surface currents were calculated and the track and velocity data of the experiment were corrected. The hydrodynamic coefficients were identified by the test data and the ship maneuvering motion model was established. The results show that the corrected data were more accurate than log data, the hydrodynamic coefficients can be completely identified, the prediction accuracy of the advance and tactical diameters were 93% and 97% and the prediction of the maneuvering model was accurate. Numerical cases verify the correction method and full-scale maneuvering model. The turning circle advance and tactical diameter satisfy the standards of the ship maneuverability of International Maritime Organization (IMO). Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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21 pages, 16325 KiB

Open AccessArticle

Energy Optimization of the ‘Shore to Ship’ System—A Universal Power System for Ships at Berth in a Port

by Sergey German-Galkin and Dariusz Tarnapowicz

Sensors 2020, 20(14), 3815; https://doi.org/10.3390/s20143815 - 08 Jul 2020

Cited by 14 | Viewed by 3042

Abstract

One of the most effective methods of limiting air pollution emissions by ships at a berth in a port is the power connection of ships to the on-shore system. “Shore to Ship” (STS)—A universal system for the connection of the ship’s electrical power [...] Read more.

One of the most effective methods of limiting air pollution emissions by ships at a berth in a port is the power connection of ships to the on-shore system. “Shore to Ship” (STS)—A universal system for the connection of the ship’s electrical power network with the on-shore network—ensures the adoption of the voltage and frequency of the on-shore network for the exploitation of various types of ships in the port. The realization of such a system is possible due to the use of semiconductor technologies during the construction of mechatronic systems (i.e., systems that ensure the maintenance of electricity parameters). The STS system ensures energy efficiency for high-power ship systems through the use of an active semiconductor converter. This article presents an analysis of steady state electromagnetic and energy processes, allowing the determination of the active and reactive power and losses in the STS system. The presented analytical research enables the development of a control algorithm that optimizes the system energy efficiency. In the article, the control methods allowing the optimization of the energy characteristics of the system are considered and investigated. On the basis of theoretical studies, a model was developed in the Matlab-Simulink environment, which allowed us to study steady and transient processes in the STS system in order to reduce losses in power lines and semiconductor converters. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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30 pages, 7176 KiB

Open AccessArticle

Evaluation of Model-Based Control of Reaction Forces at the Supports of Large-Size Crankshafts

by Leszek Chybowski, Krzysztof Nozdrzykowski, Zenon Grządziel and Lech Dorobczyński

Sensors 2020, 20(9), 2654; https://doi.org/10.3390/s20092654 - 06 May 2020

Cited by 7 | Viewed by 2439

Abstract

A support control automation system employing force sensors to a large-size crankshaft main journals’ flexible support-system was studied. The current system was intended to evaluate the geometric condition of crankshafts in internal combustion diesel engines. The support reaction forces were changed to minimize [...] Read more.

A support control automation system employing force sensors to a large-size crankshaft main journals’ flexible support-system was studied. The current system was intended to evaluate the geometric condition of crankshafts in internal combustion diesel engines. The support reaction forces were changed to minimize the crankshaft elastic deflection as a function of the crank angle. The aim of this research was to verify the hypothesis that the mentioned change can be expressed by a monoharmonic model regardless of a crankshaft structure. The authors’ investigations have confirmed this hypothesis. It was also shown that an algorithmic approach improved the mathematical model mapping with the reaction forces due to faster and more accurate calculations of a phase shift angle. The verification of the model for crankshafts with different structural designs made it possible to assess how well the model fits the coefficients of determination that were calculated with the finite element analysis (FEA). For the crankshafts analyzed, the coefficients of determination R² were greater than 0.9997, while the maximum relative percentage errors δ_max were up to 1.0228%. These values can be considered highly satisfactory for the assessment of the conducted study. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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12 pages, 1955 KiB

Open AccessArticle

Data-Driven Prediction of Vessel Propulsion Power Using Support Vector Regression with Onboard Measurement and Ocean Data

by Donghyun Kim, Sangbong Lee and Jihwan Lee

Sensors 2020, 20(6), 1588; https://doi.org/10.3390/s20061588 - 12 Mar 2020

Cited by 20 | Viewed by 3133

Abstract

The fluctuation of the oil price and the growing requirement to reduce greenhouse gas emissions have forced ship builders and shipping companies to improve the energy efficiency of the vessels. The accurate prediction of the required propulsion power at various operating condition is [...] Read more.

The fluctuation of the oil price and the growing requirement to reduce greenhouse gas emissions have forced ship builders and shipping companies to improve the energy efficiency of the vessels. The accurate prediction of the required propulsion power at various operating condition is essential to evaluate the energy-saving potential of a vessel. Currently, a new ship is expected to use the ISO15016 method in estimating added resistance induced by external environmental factors in power prediction. However, since ISO15016 usually assumes static water conditions, it may result in low accuracy when it is applied to various operating conditions. Moreover, it is time consuming to apply the ISO15016 method because it is computationally expensive and requires many input data. To overcome this limitation, we propose a data-driven approach to predict the propulsion power of a vessel. In this study, support vector regression (SVR) is used to learn from big data obtained from onboard measurement and the National Oceanic and Atmospheric Administration (NOAA) database. As a result, we show that our data-driven approach shows superior performance compared to the ISO15016 method if the big data of the solid line are secured. Full article

(This article belongs to the Special Issue Measurement Methods in the Operation of Ships and Offshore Facilities)

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