Pub Date : 2023-12-22DOI: 10.3390/machines12010007
Adolfo R. Lopez, José M. Sosa, Cristian Sámano, S. D. De Léon-Aldaco, Jesús Aguayo-Alquicira, O. López-Santos
A critical reduction in the total harmonic distortion in the output voltage of multilevel inverters can be obtained with an appropriate selection of the angles to switch the power semiconductors at low frequency. Among the methods used to obtain the required sequence of angles, it is possible to recognize both standard and optimized methods, like the Newton–Raphson method or the genetic algorithm, to mention a few. However, implementing the genetic algorithm implies using several configuration parameters, so it is difficult to know if the best option was chosen. This paper implements the Taguchi design of experiments, the Taguchi method, to obtain the appropriate switching angles for an multilevel inverter producing an output voltage of five and seven levels. Experimental results obtained from a laboratory prototype using the computed angles in the MATLAB GA solver demonstrate the superiority of the proposed method.
通过适当选择低频功率半导体开关的角度，可以显著降低多电平逆变器输出电压的总谐波失真。在用于获得所需角度序列的方法中，既有标准方法，也有优化方法，如牛顿-拉夫逊法或遗传算法等。然而，采用遗传算法需要使用多个配置参数，因此很难知道是否选择了最佳方案。本文采用田口实验设计法（Taguchi method），为产生五级和七级输出电压的多电平逆变器获得合适的开关角度。使用 MATLAB GA 求解器计算出的角度，从实验室原型机获得的实验结果证明了所提方法的优越性。
{"title":"Optimization of the Voltage Total Harmonic Distortion in Multilevel Inverters by Using the Taguchi Method","authors":"Adolfo R. Lopez, José M. Sosa, Cristian Sámano, S. D. De Léon-Aldaco, Jesús Aguayo-Alquicira, O. López-Santos","doi":"10.3390/machines12010007","DOIUrl":"https://doi.org/10.3390/machines12010007","url":null,"abstract":"A critical reduction in the total harmonic distortion in the output voltage of multilevel inverters can be obtained with an appropriate selection of the angles to switch the power semiconductors at low frequency. Among the methods used to obtain the required sequence of angles, it is possible to recognize both standard and optimized methods, like the Newton–Raphson method or the genetic algorithm, to mention a few. However, implementing the genetic algorithm implies using several configuration parameters, so it is difficult to know if the best option was chosen. This paper implements the Taguchi design of experiments, the Taguchi method, to obtain the appropriate switching angles for an multilevel inverter producing an output voltage of five and seven levels. Experimental results obtained from a laboratory prototype using the computed angles in the MATLAB GA solver demonstrate the superiority of the proposed method.","PeriodicalId":48519,"journal":{"name":"Machines","volume":"54 20","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138946381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Rubik’s Cube mechanism (RCM) is a kind of reconfigurable mechanism with multiple characteristics such as multiple configurations, variable topology, strong coupling, and reconfigurability. Crossover research on the RCM with mathematics, chemistry, cryptography, and other disciplines has led to important breakthroughs and progress. It is obvious that the invention and creation of a new RCM can provide important ideological inspiration and theoretical guidance for the accelerated iterative updating of Rubik’s Cube products and the expansion of their applications. This paper investigates the type synthesis method for a regular hexagonal prism (RHP) RCM (RHPRCM). Through analysis of the reconfigurable movement process of the RCM, two mechanism factors are abstracted, a type synthesis process for the RHPRCM is proposed, a symmetry layout method for the RCM’s revolute axis based on the RHP space polyhedron is proposed, and an analysis method for the intersection of the revolute pair contact surfaces (RPCSs) based on the adjacency matrix is proposed. Taking a revolute axis passing through the center of an RHP and having only one RPCS for each revolute axis as an example, an RHPRCM with different topological structures is synthesized. The relevant research in this paper can provide methodological guidance for the synthesis of other spatial RCMs.
{"title":"Research on the Type Synthesis of a Regular Hexagonal Prism Rubik’s Cube Mechanism","authors":"Dabao Fan, Daxing Zeng, Weijian Tan, Wenjuan Lu, Haitao Liu, Yulei Hou","doi":"10.3390/machines12010006","DOIUrl":"https://doi.org/10.3390/machines12010006","url":null,"abstract":"The Rubik’s Cube mechanism (RCM) is a kind of reconfigurable mechanism with multiple characteristics such as multiple configurations, variable topology, strong coupling, and reconfigurability. Crossover research on the RCM with mathematics, chemistry, cryptography, and other disciplines has led to important breakthroughs and progress. It is obvious that the invention and creation of a new RCM can provide important ideological inspiration and theoretical guidance for the accelerated iterative updating of Rubik’s Cube products and the expansion of their applications. This paper investigates the type synthesis method for a regular hexagonal prism (RHP) RCM (RHPRCM). Through analysis of the reconfigurable movement process of the RCM, two mechanism factors are abstracted, a type synthesis process for the RHPRCM is proposed, a symmetry layout method for the RCM’s revolute axis based on the RHP space polyhedron is proposed, and an analysis method for the intersection of the revolute pair contact surfaces (RPCSs) based on the adjacency matrix is proposed. Taking a revolute axis passing through the center of an RHP and having only one RPCS for each revolute axis as an example, an RHPRCM with different topological structures is synthesized. The relevant research in this paper can provide methodological guidance for the synthesis of other spatial RCMs.","PeriodicalId":48519,"journal":{"name":"Machines","volume":"4 5","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138950658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.3390/machines12010004
Muhammad Iftikhar Faraz, Jana Petru
The current work was undertaken with the research aim of experimental examination of tool wear, surface roughness and burr formation during the micro-milling of Inconel 718 using different coated tools. Inconel 718 is one of the most widely used materials for purpose-oriented utilization owing to its preferred mechanical and physical properties, including high strength and corrosion resistance. On the opposite end, the machining of Inconel 718 poses certain machinability challenges, which significantly elevates tool wear and subsequently surface roughness. Cutting speed, feed rate and depth of cut were selected as variable machining inputs. With reference to tool wear, all input variables were found to be significant, with tool coating having the highest contribution ratio of 36.19%. In case of surface roughness, cutting speed and tool coating were identified as effective input parameters with contribution ratios of 51.24% and 34.27%, respectively. Similarly, depth of cut proved to be an influential factor for burr height formation (in both up-milling and down-milling), whereas feed rate had the highest contribution ratios for burr width formation during up-milling and down-milling, i.e., 39.28% and 36.26%, respectively. Consequently, contour plots for output responses were drawn between significant parameters to analyze machinability. One of the vital research outcomes was the identification of a tool coating parameter that is significant for all four analyzed aspects of burr formation. In addition, regression equations were formulated for machining responses. The best- and worst-case scenarios for individual input parameters, as identified from main effects plots, were validated during confirmatory experimentation. Moreover, effects of input variables on output response were characterized using close-up imagery, and dominant wear mechanisms were also identified. The utility of the research is underlined by the optimization of the sustainability and productivity of the manufacturing process.
{"title":"Evaluation of Machining Variables on Machinability of Nickel Alloy Inconel 718 Using Coated Carbide Tools","authors":"Muhammad Iftikhar Faraz, Jana Petru","doi":"10.3390/machines12010004","DOIUrl":"https://doi.org/10.3390/machines12010004","url":null,"abstract":"The current work was undertaken with the research aim of experimental examination of tool wear, surface roughness and burr formation during the micro-milling of Inconel 718 using different coated tools. Inconel 718 is one of the most widely used materials for purpose-oriented utilization owing to its preferred mechanical and physical properties, including high strength and corrosion resistance. On the opposite end, the machining of Inconel 718 poses certain machinability challenges, which significantly elevates tool wear and subsequently surface roughness. Cutting speed, feed rate and depth of cut were selected as variable machining inputs. With reference to tool wear, all input variables were found to be significant, with tool coating having the highest contribution ratio of 36.19%. In case of surface roughness, cutting speed and tool coating were identified as effective input parameters with contribution ratios of 51.24% and 34.27%, respectively. Similarly, depth of cut proved to be an influential factor for burr height formation (in both up-milling and down-milling), whereas feed rate had the highest contribution ratios for burr width formation during up-milling and down-milling, i.e., 39.28% and 36.26%, respectively. Consequently, contour plots for output responses were drawn between significant parameters to analyze machinability. One of the vital research outcomes was the identification of a tool coating parameter that is significant for all four analyzed aspects of burr formation. In addition, regression equations were formulated for machining responses. The best- and worst-case scenarios for individual input parameters, as identified from main effects plots, were validated during confirmatory experimentation. Moreover, effects of input variables on output response were characterized using close-up imagery, and dominant wear mechanisms were also identified. The utility of the research is underlined by the optimization of the sustainability and productivity of the manufacturing process.","PeriodicalId":48519,"journal":{"name":"Machines","volume":"2 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138956083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.3390/machines12010005
Ö. F. Görçün, Sarfaraz Hashemkhani Zolfani, Hande Küçükönder, J. Antuchevičienė, Miroslavas Pavlovskis
Three-dimensional printers (3DPs), as critical parts of additive manufacturing (AM), are state-of-the-art technologies that can help practitioners with digital transformation in production processes. Three-dimensional printer performance mostly depends on good integration with artificial intelligence (AI) to outperform humans in overcoming complex tasks using 3DPs equipped with AI technology, particularly in producing an object with no smooth surface and a standard geometric shape. Hence, 3DPs also provide an opportunity to improve engineering applications in manufacturing processes. As a result, AM can create more sustainable production systems, protect the environment, and reduce external costs arising from industries’ production activities. Nonetheless, practitioners do not have sufficient willingness since this kind of transformation in production processes is a crucial and irrevocable decision requiring vast knowledge and experience. Thus, presenting a methodological frame and a roadmap may help decision-makers take more responsibility for accelerating the digital transformation of production processes. The current study aims to fill the literature’s critical theoretical and managerial gaps. Therefore, it suggests a powerful and efficient decision model for solving 3DP selection problems for industries. The suggested hybrid FF model combines the Fermatean Fuzzy Stepwise Weight Assessment Ratio Analysis (FF–SWARA) and the Fermatean Ranking of Alternatives through Functional mapping of criterion sub-intervals into a Single Interval (FF–RAFSI) approaches. The novel FF framework is employed to solve a critical problem encountered in the automobile manufacturing industry with the help of two related case studies. In addition, the criteria are identified and categorized regarding their influence degrees using a group decision approach based on an extended form of the Delphi with the aid of the Fermatean fuzzy sets. According to the conclusions of the analysis, the criteria “Accuracy” and “Quality” are the most effective measures. Also, the suggested hybrid model and its outcomes were tested by executing robustness and validation checks. The results of the analyses prove that the suggested integrated framework is a robust and practical decision-making tool.
{"title":"3D Printer Selection for the Sustainable Manufacturing Industry Using an Integrated Decision-Making Model Based on Dombi Operators in the Fermatean Fuzzy Environment","authors":"Ö. F. Görçün, Sarfaraz Hashemkhani Zolfani, Hande Küçükönder, J. Antuchevičienė, Miroslavas Pavlovskis","doi":"10.3390/machines12010005","DOIUrl":"https://doi.org/10.3390/machines12010005","url":null,"abstract":"Three-dimensional printers (3DPs), as critical parts of additive manufacturing (AM), are state-of-the-art technologies that can help practitioners with digital transformation in production processes. Three-dimensional printer performance mostly depends on good integration with artificial intelligence (AI) to outperform humans in overcoming complex tasks using 3DPs equipped with AI technology, particularly in producing an object with no smooth surface and a standard geometric shape. Hence, 3DPs also provide an opportunity to improve engineering applications in manufacturing processes. As a result, AM can create more sustainable production systems, protect the environment, and reduce external costs arising from industries’ production activities. Nonetheless, practitioners do not have sufficient willingness since this kind of transformation in production processes is a crucial and irrevocable decision requiring vast knowledge and experience. Thus, presenting a methodological frame and a roadmap may help decision-makers take more responsibility for accelerating the digital transformation of production processes. The current study aims to fill the literature’s critical theoretical and managerial gaps. Therefore, it suggests a powerful and efficient decision model for solving 3DP selection problems for industries. The suggested hybrid FF model combines the Fermatean Fuzzy Stepwise Weight Assessment Ratio Analysis (FF–SWARA) and the Fermatean Ranking of Alternatives through Functional mapping of criterion sub-intervals into a Single Interval (FF–RAFSI) approaches. The novel FF framework is employed to solve a critical problem encountered in the automobile manufacturing industry with the help of two related case studies. In addition, the criteria are identified and categorized regarding their influence degrees using a group decision approach based on an extended form of the Delphi with the aid of the Fermatean fuzzy sets. According to the conclusions of the analysis, the criteria “Accuracy” and “Quality” are the most effective measures. Also, the suggested hybrid model and its outcomes were tested by executing robustness and validation checks. The results of the analyses prove that the suggested integrated framework is a robust and practical decision-making tool.","PeriodicalId":48519,"journal":{"name":"Machines","volume":"55 7","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138954745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-20DOI: 10.3390/machines12010003
Carlos A. Reusser, Matías Parra, Cristina Stamulis, Argel Vega, Gerardo Mino
The present work deals with the design of a traction system for a hybrid vehicle using a PMSM-type motor, including an energy regeneration stage, using a Neutral Point Piloted (NPP) inverter. Optimal operation allows the motor to be supplied in the traction stage with the correct energy in such a way that it operates properly; on the other hand, during braking, it facilitates the transfer of energy in regenerative mode to the DC bus, storing the greatest amount of energy in the storage elements, which, in this case, refers to a battery bank. It also includes a DC-DC bidirectional boost interleaved converter to regulate the DC voltage levels both in traction and in braking. Its fundamental characteristic is that with a reduced number of switching devices, it allows for the reduction in DC voltage of the DC bus with adequate characteristics, constant and stable, regardless of abrupt changes in the output voltage reference value. Also, other features include oscillation control, that is, reducing or increasing oscillations according to operating conditions. Its transient operation is excellent, since the settling time is considerably reduced, which implies that the voltage of the DC bus does not cause mishaps in the operation of the motor. In its operation as a boost converter, in the event of any voltage value of the DC bus, the converter raises the voltage value according to the reference conditions. Similarly, control allows the voltage to be held at a stable value regardless of changes in the set point. This work presents a novel energy management scheme for permanent magnet electric drive based on a Model Predictive Control strategy, thus contributing to the effective energy management of a standard hybrid electric vehicle driving cycle. Results obtained using a real-time Hardware-in-the-Loop (HIL) platform showed the effectiveness of Model Predictive Control in dealing with power flow management while ensuring control of electric drive in all the required speed–torque profiles.
{"title":"Novel Energy Management Scheme for a Permanent Magnet Electric Drive-Based Hybrid Vehicle Using Model Predictive Control","authors":"Carlos A. Reusser, Matías Parra, Cristina Stamulis, Argel Vega, Gerardo Mino","doi":"10.3390/machines12010003","DOIUrl":"https://doi.org/10.3390/machines12010003","url":null,"abstract":"The present work deals with the design of a traction system for a hybrid vehicle using a PMSM-type motor, including an energy regeneration stage, using a Neutral Point Piloted (NPP) inverter. Optimal operation allows the motor to be supplied in the traction stage with the correct energy in such a way that it operates properly; on the other hand, during braking, it facilitates the transfer of energy in regenerative mode to the DC bus, storing the greatest amount of energy in the storage elements, which, in this case, refers to a battery bank. It also includes a DC-DC bidirectional boost interleaved converter to regulate the DC voltage levels both in traction and in braking. Its fundamental characteristic is that with a reduced number of switching devices, it allows for the reduction in DC voltage of the DC bus with adequate characteristics, constant and stable, regardless of abrupt changes in the output voltage reference value. Also, other features include oscillation control, that is, reducing or increasing oscillations according to operating conditions. Its transient operation is excellent, since the settling time is considerably reduced, which implies that the voltage of the DC bus does not cause mishaps in the operation of the motor. In its operation as a boost converter, in the event of any voltage value of the DC bus, the converter raises the voltage value according to the reference conditions. Similarly, control allows the voltage to be held at a stable value regardless of changes in the set point. This work presents a novel energy management scheme for permanent magnet electric drive based on a Model Predictive Control strategy, thus contributing to the effective energy management of a standard hybrid electric vehicle driving cycle. Results obtained using a real-time Hardware-in-the-Loop (HIL) platform showed the effectiveness of Model Predictive Control in dealing with power flow management while ensuring control of electric drive in all the required speed–torque profiles.","PeriodicalId":48519,"journal":{"name":"Machines","volume":"94 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139170261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.3390/machines12010002
Konstantin Novikov, P. Hořejší, Jan Kubr, Matěj Dvořák, Miroslav Bednář, David Krákora, Matěj Krňoul, M. Šimon
This article deals with the rationalization of manufacturing processes within the product life cycle with emphasis on the pre-production phase of production. A new methodology for evaluating the applicability of modern visualization tools in manufacturing processes is presented. This methodology includes a modified Z-score for categorizing manufacturing processes and has been validated by the successful implementation of 10 real projects. Ultimately, the methodology provides a practical decision-making aid for manufacturing companies in deploying such Computer Aided Instruction tools. For the pre-production phase of products and their development, the possibilities of using modern visualization tools to support CAD instructions and assembly instructions are being explored. These modern visualization tools are video tutorials, augmented reality tutorials and virtual reality tutorials. This paper explores the use of these tools for rationalization of pre-production processes. A methodology was designed to select the most appropriate tool for rationalizing process execution in preparation for production. The functionality of the methodology was verified by applying the methodology in industrial practice and subsequent implementation of the recommended solutions. The methodology was validated by testing key combinations that can arise based on the methodology directly in the operations of manufacturing companies. A total of 10 implementations in real production processes were tailored to this study and carried out over 2 years and the functionality of the methodology was confirmed (that consisted also of a new software development). It was found that there is a dependency between the visualization tools chosen to create the instructions in the context of organizational production preparation and the nature of the production processes.
{"title":"Methodology for Rationalization of Pre-Production Processes Using Virtual Reality Based Manufacturing Instructions","authors":"Konstantin Novikov, P. Hořejší, Jan Kubr, Matěj Dvořák, Miroslav Bednář, David Krákora, Matěj Krňoul, M. Šimon","doi":"10.3390/machines12010002","DOIUrl":"https://doi.org/10.3390/machines12010002","url":null,"abstract":"This article deals with the rationalization of manufacturing processes within the product life cycle with emphasis on the pre-production phase of production. A new methodology for evaluating the applicability of modern visualization tools in manufacturing processes is presented. This methodology includes a modified Z-score for categorizing manufacturing processes and has been validated by the successful implementation of 10 real projects. Ultimately, the methodology provides a practical decision-making aid for manufacturing companies in deploying such Computer Aided Instruction tools. For the pre-production phase of products and their development, the possibilities of using modern visualization tools to support CAD instructions and assembly instructions are being explored. These modern visualization tools are video tutorials, augmented reality tutorials and virtual reality tutorials. This paper explores the use of these tools for rationalization of pre-production processes. A methodology was designed to select the most appropriate tool for rationalizing process execution in preparation for production. The functionality of the methodology was verified by applying the methodology in industrial practice and subsequent implementation of the recommended solutions. The methodology was validated by testing key combinations that can arise based on the methodology directly in the operations of manufacturing companies. A total of 10 implementations in real production processes were tailored to this study and carried out over 2 years and the functionality of the methodology was confirmed (that consisted also of a new software development). It was found that there is a dependency between the visualization tools chosen to create the instructions in the context of organizational production preparation and the nature of the production processes.","PeriodicalId":48519,"journal":{"name":"Machines","volume":" 51","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138961056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-19DOI: 10.3390/machines12010001
Fernando Gómez-Bravo, Alejandro Garrocho-Cruz, Olga Marín-Cañas, I. Pulido-Calvo, J. C. Gutiérrez-Estrada, Antonio Peregrín-Rubio
This article introduces a control architecture designed for the development of Hybrid Remotely Operated Underwater Vehicles. The term ”Hybrid” characterizes Remotely Operated systems capable of autonomously executing specific operations. The presented architecture maintains teleoperation capabilities while enabling two fully autonomous applications. The approach emphasizes the implementation of reactive navigation by exclusively utilizing data from a Mechanical Scanned Imaging Sonar for control decisions. This mandates the control system to solely react to data derived from the vehicle’s environment, without considering other positioning information or state estimation. The study involves transforming a small-scale commercial Remotely Operated Underwater Vehicle into a hybrid system without structural modifications, and details the development of an intermediate Operational Control Layer responsible for sensor data processing and task execution control. Two practical applications, inspired by tasks common in natural or open-water aquaculture farms, are explored: one for conducting transects, facilitating monitoring and maintenance operations, and another for navigating toward an object for inspection purposes. Experimental results validate the feasibility and effectiveness of the authors’ hypotheses. This approach expands the potential applications of underwater vehicles and facilitates the development of Hybrid Remotely Operated Underwater Vehicles, enabling the execution of autonomous reactive tasks.
{"title":"A Control Architecture for Developing Reactive Hybrid Remotely Operated Underwater Vehicles","authors":"Fernando Gómez-Bravo, Alejandro Garrocho-Cruz, Olga Marín-Cañas, I. Pulido-Calvo, J. C. Gutiérrez-Estrada, Antonio Peregrín-Rubio","doi":"10.3390/machines12010001","DOIUrl":"https://doi.org/10.3390/machines12010001","url":null,"abstract":"This article introduces a control architecture designed for the development of Hybrid Remotely Operated Underwater Vehicles. The term ”Hybrid” characterizes Remotely Operated systems capable of autonomously executing specific operations. The presented architecture maintains teleoperation capabilities while enabling two fully autonomous applications. The approach emphasizes the implementation of reactive navigation by exclusively utilizing data from a Mechanical Scanned Imaging Sonar for control decisions. This mandates the control system to solely react to data derived from the vehicle’s environment, without considering other positioning information or state estimation. The study involves transforming a small-scale commercial Remotely Operated Underwater Vehicle into a hybrid system without structural modifications, and details the development of an intermediate Operational Control Layer responsible for sensor data processing and task execution control. Two practical applications, inspired by tasks common in natural or open-water aquaculture farms, are explored: one for conducting transects, facilitating monitoring and maintenance operations, and another for navigating toward an object for inspection purposes. Experimental results validate the feasibility and effectiveness of the authors’ hypotheses. This approach expands the potential applications of underwater vehicles and facilitates the development of Hybrid Remotely Operated Underwater Vehicles, enabling the execution of autonomous reactive tasks.","PeriodicalId":48519,"journal":{"name":"Machines","volume":" 12","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138961704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-16DOI: 10.3390/machines11121091
P. Martinez‐Rodriguez, Gerardo Vázquez-Guzman, Gerardo O. Perez-Bustos, J. M. Sosa-Zuniga, Dalyndha Aztatzi-Pluma, Adolfo R. Lopez-Nuñez, Christopher J. Rodríguez-Cortés
Transformerless inverters have an important role in the electrical energy market. The high-efficiency and reliable inverter concept is one of the most widely used inverters in single-phase photovoltaic systems because of its high efficiency, low cost, and reduced leakage ground current. However, the leakage ground current behavior depends on the power and weather conditions, which can increase the parasitic capacitance value, thus producing an increase in the leakage ground current magnitude. In this paper, it is proposed to add a passive inductive–capacitive output filter to the inverter structure in order to reduce the dependency of the leakage ground current on the system power and weather conditions. The inductive–capacitive output filter is designed in such a way that it can provide a low impedance path for the leakage ground current, different from the ground path. The proposed system was evaluated both through simulations and experimentally in a 1 kW laboratory prototype.
{"title":"Analysis and Improved Behavior of a Single-Phase Transformerless PV Inverter","authors":"P. Martinez‐Rodriguez, Gerardo Vázquez-Guzman, Gerardo O. Perez-Bustos, J. M. Sosa-Zuniga, Dalyndha Aztatzi-Pluma, Adolfo R. Lopez-Nuñez, Christopher J. Rodríguez-Cortés","doi":"10.3390/machines11121091","DOIUrl":"https://doi.org/10.3390/machines11121091","url":null,"abstract":"Transformerless inverters have an important role in the electrical energy market. The high-efficiency and reliable inverter concept is one of the most widely used inverters in single-phase photovoltaic systems because of its high efficiency, low cost, and reduced leakage ground current. However, the leakage ground current behavior depends on the power and weather conditions, which can increase the parasitic capacitance value, thus producing an increase in the leakage ground current magnitude. In this paper, it is proposed to add a passive inductive–capacitive output filter to the inverter structure in order to reduce the dependency of the leakage ground current on the system power and weather conditions. The inductive–capacitive output filter is designed in such a way that it can provide a low impedance path for the leakage ground current, different from the ground path. The proposed system was evaluated both through simulations and experimentally in a 1 kW laboratory prototype.","PeriodicalId":48519,"journal":{"name":"Machines","volume":"36 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138967844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-15DOI: 10.3390/machines11121090
Didem Tekgun
The shaft eddy currents cause a significant saturation in two-pole induction machines (IMs) as they generate an opposing field and repulse the main flux, thus tightening the flux path. This results in inaccurate performance estimations with the magnetizing inductance measured in no-load conditions when the machine is loaded. This article presents a modified IM equivalent circuit considering the rotor back iron saturation effects caused by the solid shaft eddy currents using experimental measurements and recursive parameter estimation techniques. The classical equivalent circuit (CEC) parameters are determined with the standard test techniques followed by the parameter estimation of the newly introduced modified equivalent circuit (MEC) parameters. The proposed modified equivalent circuit is benchmarked with CEC and finite element analysis (FEA) simulations with and without considering eddy effects. The proposed MEC model and the FEA that consider eddy effects performed better than the other models and yielded a negligibly small error over a wide range of loading conditions. Compared to the FEA, the proposed MEC estimates the IM performance much faster, which makes it more appealing for IM performance estimations.
轴涡流会在两极感应电机（IM）中造成显著的饱和，因为它们会产生相反的磁场并排斥主磁通，从而收紧磁通路径。这导致在空载条件下测量的磁化电感与机器负载时的性能估计不准确。本文利用实验测量和递归参数估计技术，提出了一种改进的 IM 等效电路，其中考虑到了由实心轴涡流引起的转子背铁饱和效应。先用标准测试技术确定经典等效电路 (CEC) 参数，然后对新引入的修正等效电路 (MEC) 参数进行参数估计。在考虑和不考虑涡流效应的情况下，用 CEC 和有限元分析 (FEA) 模拟对提出的修正等效电路进行了基准测试。建议的 MEC 模型和考虑了涡流效应的有限元分析比其他模型性能更好，在各种负载条件下产生的误差小到可以忽略不计。与有限元分析相比，所提出的 MEC 估算 IM 性能的速度更快，这使其在 IM 性能估算方面更具吸引力。
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Pub Date : 2023-12-14DOI: 10.3390/machines11121089
Tarek Berghout, Toufik Bentrcia, Wei Hong Lim, Mohamed Benbouzid
The deep learning diagnosis of aircraft engine-bearing faults enables cost-effective predictive maintenance while playing an important role in increasing the safety, reliability, and efficiency of aircraft operations. Because of highly dynamic and harsh operating conditions of this system, such modeling is challenging due to data complexity and drift, making it difficult to reveal failure patterns. As a result, the objective of this study is dual. To begin, a highly structured data preprocessing strategy ranging from extraction, denoising, outlier removal, scaling, and balancing is provided to solve data complexity that resides specifically in outliers, noise, and data imbalance problems. Gap statistics under k-means clustering are used to evaluate preprocessing results, providing a quantitative estimate of the ideal number of clusters and thereby enhancing data representations. This is the first time, to the best of authors’ knowledge, that such a criterion has been employed for an important step in a preliminary ground truth validation in supervised learning. Furthermore, to tackle data drift issues, long-short term memory (LSTM) adaptive learning features are used and subjected to a learning parameter improvement method utilizing recursive weights initialization (RWI) across several rounds. The strength of such methodology can be seen by application to realistic, extremely new, complex, and dynamic data collected from a real test-bench. Cross validation of a single LSTM layer model with only 10 neurons shows its ability to enhance classification performance by 7.7508% over state-of-the-art results, obtaining a classification accuracy of 92.03 ± 0.0849%, which is an exceptional performance in such a benchmark.
{"title":"A Neural Network Weights Initialization Approach for Diagnosing Real Aircraft Engine Inter-Shaft Bearing Faults","authors":"Tarek Berghout, Toufik Bentrcia, Wei Hong Lim, Mohamed Benbouzid","doi":"10.3390/machines11121089","DOIUrl":"https://doi.org/10.3390/machines11121089","url":null,"abstract":"The deep learning diagnosis of aircraft engine-bearing faults enables cost-effective predictive maintenance while playing an important role in increasing the safety, reliability, and efficiency of aircraft operations. Because of highly dynamic and harsh operating conditions of this system, such modeling is challenging due to data complexity and drift, making it difficult to reveal failure patterns. As a result, the objective of this study is dual. To begin, a highly structured data preprocessing strategy ranging from extraction, denoising, outlier removal, scaling, and balancing is provided to solve data complexity that resides specifically in outliers, noise, and data imbalance problems. Gap statistics under k-means clustering are used to evaluate preprocessing results, providing a quantitative estimate of the ideal number of clusters and thereby enhancing data representations. This is the first time, to the best of authors’ knowledge, that such a criterion has been employed for an important step in a preliminary ground truth validation in supervised learning. Furthermore, to tackle data drift issues, long-short term memory (LSTM) adaptive learning features are used and subjected to a learning parameter improvement method utilizing recursive weights initialization (RWI) across several rounds. The strength of such methodology can be seen by application to realistic, extremely new, complex, and dynamic data collected from a real test-bench. Cross validation of a single LSTM layer model with only 10 neurons shows its ability to enhance classification performance by 7.7508% over state-of-the-art results, obtaining a classification accuracy of 92.03 ± 0.0849%, which is an exceptional performance in such a benchmark.","PeriodicalId":48519,"journal":{"name":"Machines","volume":"24 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138974755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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