Advances in Science and Technology Vol. 165

Abstract: The majority of passengers on sea cruises do not even think that they endanger the environment and human health more with a cruise of at least one week than if they had chosen another way of travel. The large amount of fuel burned during the journey pollutes the atmosphere and thus endangers health, and all kinds of (dangerous) waste and sewage generated daily on ships cannot remain on board. A ship carrying an approx. 3,000 passengers produces an average of nearly 80 m3 of wastewater per day! Newer ships are often capable of carrying 8,000 passengers, so their daily waste water production is obviously larger than this. It is enough to see these huge floating cities with 10-12 floors (Fig. 1.)

Abstract: Predicting the Remaining Useful Life (RUL) of machinery and critical components is crucial for proactive maintenance and operational efficiency in industrial settings. This paper presents an approach to RUL prediction using the AdaBoost algorithm, a technique that iteratively improves prediction accuracy by focusing on difficult-to-predict cases. The AdaBoost algorithm will be extended to handle both binary and multi-class classification, enabling it to distinguish between various stages of degradation. By providing more granular insights into the health status of components, this approach enhances maintenance planning by allowing for more targeted, condition-based interventions. Early detection of varying levels of wear allows maintenance teams to schedule repairs or part replacements precisely when needed, reducing unplanned downtime and optimizing resource allocation. This study demonstrates the adaptability of AdaBoost in handling complex RUL prediction scenarios, thus supporting a more effective and data-driven approach to predictive maintenance in industrial applications.

Abstract: This study details the design, assembly, and measurement processes of a modified test bench for examining sliding ring seals. We designed a test bench suitable for measuring mechanical seals, during which we first developed the concept and the design of the bench, defined the parameters to be measured and the measurement methods, and then implemented these objectives using an existing test bench. After procuring raw materials, I manufactured and assembled the necessary components, including acid-resistant and corrosion-resistant steel parts. Key machining operations were performed, such as drilling and threading, to accommodate the mechanical seals and ensure proper alignment. Following assembly, I conducted three reference measurements with varying compressive spring forces. The system's torque was measured at a consistent rotational speed of 200 RPM. Results from the frictional torque measurements revealed that the seals displayed sensitivity to compressive forces, confirming the effectiveness of the modified test bench for future seal evaluations.

Abstract: As the treat landscape in Operational Technology (OT) cyber security is getting more complicated, there is a general demand in most industries to increase the Target Security Level (SL-T) of Industry Automation and Control Systems (IACS). More sophisticated treat actors with higher motivation are on stage, and treat actors are getting increasingly familiar with IACS. Yet some security controls, widely used in Information Technology, are often hard to implement in IACS. Inability to go away from obsolete Operational System (OS), using shared accounts for operators, limited applicability of security patching, limited applicability of multifactor authentication, Intrusion Prevention Systems (IPS) are specific challenges of IACS security, caused mainly by real time operation and safety requirements. One way to reach SL-T is introducing compensating controls. For instance, if the use of an obsolete, unpatched SCADA system is unavoidable, security monitoring or physical security can be increased to compensate the lack of direct control. This paper aims to elaborate the compensating effect of continuous authentication as a mean of Identification and Authentication (I&A) for the operating room workstations of obsolete SCADA and DCS systems.

Abstract: The study focuses on simulating the current and future value stream of external cable production, identifying bottlenecks, and proposing improvements. It provides a comprehensive overview of production processes, analyzing their current state and modeling future developments. Utilizing Visual Components simulation software, the study evaluates modernization efforts and quantifies their impact. Special attention is given to lean management, Industry 4.0, and robotics. The results guide recommendations for optimizing workstations, workforce, and efficiency, ensuring a more balanced and streamlined production process.

Abstract: One of the critical aspects in performance optimization of energy efficiency for a Brushless DC (BLDC) motor applied to hedge cutters is that of cutting force versus current consumption. The mechanical cutting force produced during the hedge cutting operation will be presented, here, in a manner relating to the electrical current drawn by the BLDC motor. It indicates that the cutting forces depend on the blade's sharpness, the density of the material, the speed of cutting; and that the current consumed by the motor is directly proportional to the value of this cutting force. The outcome of this study reveals that motor current monitoring performs favorably as an alternative measurement of the resistance of cut and mechanical load in real-time, seeking to enable the implementation of intelligent systems for performance optimization and predicting maintenance. The findings from this will also be beneficial in designing energy-efficient motors for custom-made cutting conditions and thus increase the overall robustness and cost-effective aspects related to operation of hedge cutters. A more accurate representation of this relationship can be refined through further research focusing on material properties and motor control algorithms, allowing for better use of energy and more precise control of horticultural implements. The aim of this paper is to investigate the relation between the different cutting forces occurring during the hedge trimming process and the current consumption of the BLDC motor. The paper will approach this question from a theoretical (calculation and simulation) point of view.

Abstract: This study contributes to the development of more resilient and responsive control systems for industrial robotics. Industrial robot arms are subject to various vibrational forces during various operations, which can limit their accuracy and response time. This paper studies the vibration characteristics of a robotic arm through real world measurement and Finite Element Analysis (FEA). The robot arm is the MELFA RV-2SDB15. In this paper, the authors determine the dynamic parameters of the examined manipulator. Experimental measurement is carried out with a modal approach. Optimization techniques are employed to develop an accurate CAD model of the robotic arm.

Abstract: This paper shows the application of discrete wavelet transform in the analysis of ECG signals to detect R-peaks of the QRS complex. The proper analysis of the ECG signal is crucial to reveal the changes in the waveform to detect heart related diseases. The detection of the P-wave, T-wave, QRS complex is important and the wavelet transform offers a good possibility to recognize the abnormalities. Three different wavelets, Symlet, Coiflet and Daubechies are used for the detection and are compared to choose the most efficient one to identify the R-peaks. Multiresolution analysis (MRA) is used to determine the sufficient level of decomposition. MIT-BIH Arrhythmia Database is used as a dataset for the experiment.

Abstract: X-ray computed tomography (CT) is becoming more commonly used in industry, in addi-tion to material testing, it is also suitable for dimensional measurements for metrological purposes.A great advantage of CT is that it is appropriate for evaluating dimensional characteristics of outerand inner surfaces in a non-destructive manner. But due to the complexity of CT dimensional mea-surements, several influencing factors affect the accuracy of the method. It is also a complicatingaspect that the metrological traceability of CT measurements is not fully developed. The precisionand accuracy of dimensional measurements by CT are affected by several factors including the objectof investigation and the measurement parameters. These factors may contribute to the difference be-tween the true value and the measured value of the length of a certain workpiece when measured byCT. It is yet an unsolved issue to determine all the effects to reduce measurement error and uncertainty.One particularly significant factor related to the measured object is its surface quality, which plays acritical role in affecting the reliability of CT measurements. Since the dependence of such deviationsfrom surface morphology has not yet been thoroughly examined, our aim is to study the influence ofsurface roughness on CT dimensional measurements by looking for correlation between the precisionof the length of 3D-printed workpieces measured by CT and the surface roughness of the sides ofthe workpieces. A slight negative correlation (with correlation coefficients −0.35 < r < −0.4) hasbeen shown between measurement errors and the average values of Ra, Rz and Rp, contrary to theprevious literature, where linear relationships have been found instead and the relationship with Rahas not been examined. It highlights the fact that this topic is not yet worked out in detail due to thecomplexity and unstandardized processes of CT measurements.

Abstract: Injection moulding is the most diverse and dynamically developing polymer processing technology. Conventional injection moulding is economically viable only in large-volume part production. However, there is an ever-growing demand for more customised, low-volume plastic products, which is called mass customization. This need can be served by the hybridisation of injection moulding with additively manufactured, low-volume injection moulds (produced for example from thermoset resins by PolyJet technology). In our work, we elaborated a novel state-monitoring and modelling method to analyse the mechanical and thermal characteristics (strains and temperature distribution) of these polymeric injection mould inserts during operation. The results of the modelling method were successfully validated by the actual injection moulding experiments, proving the adequacy of the modelling method.