IMEKO Event Proceedings Search

Page 142 of 977 Results 1411 - 1420 of 9762

Zsolt János Viharos, Richárd Jakab
Reinforcement Learning for Statistical Process Control in Manufacturing

The main concept of the paper is to place Reinforcement Learning (RL) into various fields of manufacturing. As a first attempt, RL for Statistical Process Control (SPC) in production is introduced in the paper; it is a promising approach owing to the adaptability and continuous application capability of reinforcement learning. The well-known Q-Table method was applied for get more stable, predictable and easy to overview results, therefore, quantization of the values of the time series to stripes was required. The formulated goal was to predict the time series value in a certain number of production steps ahead as manufacturing trend forecast. The recent values of the analysed time series were selected as states for the RL and the future probabilities of its values being in the formulated stripes were defined as RL actions. For action update, the Bellman equation was applied and the RL reward depends on how accurate the predicting is. Furthermore, two concepts were introduced, the Reusing Window (RW) and the Measurement Window (MW). The RW is a sliding window that determines how many times one measured value of the time series will be reused during the RL repeatedly, while the MW is defined for enabling the comparison of learnings with different RWs by sampling them with the same evaluation frequency.

Antonio Vasilijevic, Nadir Kapetanović, Nikola Mišković
Inspection of Submerged Structures

Very common motivation for the inspection of underwater infrastructures is to measure and estimate their degradation status. Measurements required for this estimation could vary for different inspections but often include the size of the gap between the underwater structure and the seabed, between two structures or openings or cracks on the structure itself. Marine environment is very challenging for accurate spatial measurements because it is GPS-denied environment due to very high attenuation of the radio waves and because of very limited penetration of visual and laser signals, methods that are commonly used in terrestrial applications. Alternatives generally applied underwater are acoustic instruments for range measurement. The most appropriate instrument for multiple simultaneous range measurement is multibeam profiling sonar. In this paper, we describe the use case related to the inspection and monitoring of the degradation status of the steel hull of the ship that sunk one hundred years ago. The profiling multi-beam sonar attached to an Autonomous Surface Vehicle was used to inspect the degradation status i.e. to measure the gap along the ship side. These sea trials have showed that reliable estimation of submerged gaps/cracks and openings could be obtained utilizing this methodology.

Bartosz Połok, Piotr Bilski
Diagnostics of the ratchet mechanism using the acoustic analysis

The paper presents the measurement system for the diagnostics of the ratchet mechanisms based on the acoustic signal analysis. Such mechanisms are common in such devices, as drive elements in bicycles, safe locks or socket wrenches. Their exploitation may lead to wearing out teeth in gears, which is significant in the sport bicycles. To ensure safety of their user, the mechanism’s state has to be evaluated. Based on the symptoms extracted from the audio recordings the Artificial Intelligence-based classifier can be used to detect and locate faults related with the pawl degradation. Experiments were performed to verify the system’s efficiency during the analysis of the selected gears in the sport (BMX-type) bicycle. They included determining the ability to operate in the noisy conditions and identifying faults by the decision tree, both in the standalone and boosted version. The system’s accuracy above 90% proves its applicability to analyze the real-world objects.

Sergey V Muravyov, Liudmila I Khudonogova, Dai Minh Ho
Precise Measurand Value Estimating by Interval Fusion with Preference Aggregation: Heteroscedasticity Case

It is considered the problem of determination of a reference value for heteroscedastic interval data. For this aim, the newly proposed by the authors interval fusion with preference aggregation (IF&PA) procedure is used. The procedure, modified to improve the accuracy of the fusion result, is presented and applied to process the heteroscedastic data of a real experiment. The experiment consisted in determination of the reference value of DC voltage based on the readings of five different models of multimeters. For comparison, the same data were processed by the method of weighted mean. For two methods, an absolute deviations of the obtained reference values from the nominal value (which is a high-precision calibrator output) and reference value uncertainties were estimated. It is shown that the IF&PA procedure allows to obtain a reference value very close to nominal value and with considerably reduced uncertainty in comparison with traditional method based on weighted mean calculation.

Ildikó Bölkény
AI Based Detection of Gas Hydrate Formation

In the production process of natural gas one of the major problems is the formation of hydrate crystals creating hydrate plugs in the pipeline. The hydrate plugs increase production losses, because the removal of the plugs is a high cost, time consuming procedure. One of the solutions used to prevent hydrate formation is the injection of modern compositions to the gas flow, helping to dehydrate the gas. Dehydratation obviously means that the size of hydrate crystals does not increase. The substances used in low concentrations, have to be locally injected at the gas well sites. Inhibitor dosing depends on the amount of gas hydrate present. In the article two Artificial Neural Network (ANN)-based predictive detection solutions are presented. In both cases the goal is to predict hydrate formation. Data used come from two solutions. In the first one measurements were performed by a self-developed and -produced equipment (in this case, differential pressure was used as input). In the second solution data are used from the measurement system of a motorised chemical-injector device (pressure, temperature, quantity and type of inhibitor were used as inputs). Both systems are presented in the article.

Antonella Gaspari, Emanuela Natale, Armando De Silvestri , Giulio D’Emilia
Effect Of Measurement Uncertainty On Artificial Vision Methods, For Quality Control On Composite Components

In this work, an inspection strategy by a vision system is analysed, for the identification of surface and aesthetical defects, with reference to composite components for automotive and aeronautical industrial sectors. Attention is paid to the background identification, since the specificity of the application requires particular care in order to avoid misunderstandings and false negatives during the detection phase. The evaluation of the parameters setup effects is used for the identification of the main uncertainty contributions, which is a strong support for the most suitable choice of the monitoring strategy. The robustness of the approach is studied with reference to several laboratory datasets, representing some commonly found issues for an easy in-field transfer. To this aim, some commercial tools available in Matlab ® environment have been used. The obtained results encourage to monitor the variability of the performances rates, depending on the qualitative levels to be achieved during the operating conditions and on the desired reliability of the approach.

Grzegorz Makarewicz, Piotr Bilski
Diagnostics of the RIAA Equalizer in a Turntable Using Artificial Neural Network

The following paper presents the methodology of RIAA equalizer condition analysis based on measurements of its amplitude and phase characteristics. The RIAA equalizer is used during the signal recording and is an integral part of modern turntables. It’s parameters determine the quality of the music being played. The task is to determine the critical values of electronic components (capacitors) based on the characteristics of signals observed at the circuit’s output. It is considered difficult due to the presence of noise, elements’ tolerances, and simultaneous drift of several system’s parameters. The presented methodology uses the Artificial Intelligence (AI) module that implements the task of parameter identification. The knowledge exploited by the AI-based module is extracted during machine learning, based on the dataset obtained during the simulations of the equalizer’s computer model. For the decisionmaking module, the standard tool for the regression tasks, i.e. RBF-type Artificial Neural Network (ANN) was used. The obtained results allow for considering the potentially high usefulness of the presented approach for the parameters identification in electronic circuits used in audio technology.

Vicki J. Barwick
Ensuring the quality of analytical measurements – current support and future challenges

Established in 1989, the aim of Eurachem is to provide a focus for analytical chemistry and qualityrelated issues in Europe. The main objectives are establishing a system for the international traceability of chemical measurement results and the promotion of good quality practices. Eurachem currently has 36 member countries and is effectively a ‘network of networks’. A requirement of membership is the establishment of a national Eurachem network which supports the dissemination of Eurachem’s aims and outputs. Eurachem also has liaison arrangements with a number of European and international organisations. In 2019, Eurachem marked its 30th anniversary. While the network is ‘badged’ as a focus for analytical chemistry in Europe, in recent years the audience for Eurachem activities has become much broader than analytical chemists making measurements in a laboratory setting. Interest in quality assurance now extends across a broad range of disciplines and measurement environments. This paper will review Eurachem’s achievements over the past 30 years and look forward to some of the challenges ahead.

Yukio Hiranaka, Koichi Tsujino
VAE Deviation for Detecting Bearing Anomalies

Anomaly of rotating machines are usually inferred from vibration measurements. However, it is not easy to determine the normal range for conventional crest factor or primary component analysis. In this paper, we try to use the Artificial Neural Network technique to make judgments based on the degree of deviation from the learned normal range. Specifically, we evaluated VAE which compresses the measured sensor data into the latent space of smaller number of dimensions with standard normal distributions. We propose an anomaly score which indicates the deviation from the center of the normal distribution using linear VAE calculation and dimensionality compensation. The proposed anomaly score shows good performance with several test data sets and measured real data sets.

Somil Joshi, Girish Pathak
Testing, diagnosis and rectification of high dissipation factor in large power transformer

Power transformer are high-priced and major device in electrical power system. Their overall healthiness and operating life is primarily dependent on insulation system. Insulation system of transformer is complex electrical network comprising series and shunt capacitance. These capacitance comprises of insulating components like oil, wood, paper and pre compressed boards (PCBs). As these materials are hygroscopic and moisture prone. Hence fault identification and rectification in insulation system becomes critical. There are several methods available for accessing the power transformer insulation. This paper demonstrates a practical experience, methodology of testing and diagnosis. Through testing components responsible for high dissipation factor were identified. The diagnostic technique helped in swift and economical replacement of faulty insulation components. Thus, high dissipation factor problem rectified and transformer was restored back to service

Page 142 of 977 Results 1411 - 1420 of 9762