DIM - MAQLAB - Artículos de revistas

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An Artificial Intelligence Approach for Gears Diagnostics in AUVs
(MPDI, 2016-04-01) Nicolas Marichal, Graciliano; Del Castillo Zas, María Lourdes; López López, Jesús; Padrón, Isidro; Artes Gomez, Mariano; Ministerio de Economía y Competitividad (España)
In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised.
Experimental validation of a plier with two retractable fingers
(DYNA, 2016-02) Soriano Heras, Enrique; Rubio Alonso, Higinio; García Prada, Juan Carlos; Carbone, Giuseppe
This paper presents analytical, numerical, and experimental testing models for designing and validating the feasibility of a gripper with two retractable fingers. The proposed gripper is specifically developed for grasping and manipulating objects that should be kept into restricted areas such as explosives, radioactive/ionized materials, and infected biological material specimens. The proposed gripper fingers can be retracted to pass through openings or slots and, once inside the restricted area, can be deployed in order to manipulate the objects without risk for the human operators. Analytical and numerical simulations are used to properly design and build a gripper prototype. Then, experimental tests are carried out to grasp objects of different sizes ranging from 5 to 10 mm. The obtained results are used to validate the gripper"s performance in terms of successful grasp and suitable accelerations and grasp forces.
The Quasi-Passive Quadruped Robot walking: PASIQUAD
(MedCrave Group, LLC, 2017-06-20) Corral Abad, Eduardo; Gómez García, María Jesús; Meneses Alonso, Jesús; García Prada, Juan Carlos
The design of the four legged walking robot "PASIQUAD" is presented in this article. It was designed in the university Carlos III of Madrid. It is a quadruped quasi-passive robot (with only one motor/actuator). The manuscript is focused on how the PASIQUAD walks and the kinematics and dynamics of the movement. In the manuscript the position, velocity and acceleration of each of its parts, as well as all the forces and torques on each of them, motor torque included, will be explain. The PASIQUAD robot copy the movement of animals and it is almost passive. That is a big advantage in energy cost.
Interfacial mechanisms for stability of surfactant-laden films
(PLOS, 2017-05-17) Bhamla, M. Saad; Álvarez Valenzuela, Marco Antonio; Tajuelo, Javier; Fuller, Gerald G.; Ministerio de Educación, Cultura y Deporte (España)
Thin liquid films are central to everyday life. They are ubiquitous in modern technology (pharmaceuticals, coatings), consumer products (foams, emulsions) and also serve vital biological functions (tear film of the eye, pulmonary surfactants in the lung). A common feature in all these examples is the presence of surface-active molecules at the air-liquid interface. Though they form only molecular-thin layers, these surfactants produce complex surface stresses on the free surface, which have important consequences for the dynamics and stability of the underlying thin liquid film. Here we conduct simple thinning experiments to explore the fundamental mechanisms that allow the surfactant molecules to slow the gravity-driven drainage of the underlying film. We present a simple model that works for both soluble and insoluble surfactant systems in the limit of negligible adsorption-desorption dynamics. We show that surfactants with finite surface rheology influence bulk flow through viscoelastic interfacial stresses, while surfactants with inviscid surfaces achieve stability through opposing surface-tension induced Marangoni flows.
Design and test of cryogenic cold plate for thermal-vacuum testing of space components
(MDPI, 2019-08-02) Díez Jiménez, Efrén; Alcover-Sanchez, Roberto; Pereira, Emiliano; Gómez García, María Jesús; Martinez Vian, Patricia; Ministerio de Economía y Competitividad (España)
This paper proposes a novel cryogenic fluid cold plate designed for the testing of cryogenic space components. The cold plate is able to achieve cryogenic temperature operation down to -196 °C with a low liquid nitrogen (LN2) consumption. A good tradeoff between high rigidity and low thermal conduction is achieved thanks to a hexapod configuration, which is formed by six hinge-axle-hole articulations in which each linking rod bears only axial loads. Thus, there is not any stress concentration, which reduces the diameter of rod sections and reduces the rods' thermal conduction. This novel design has a unique set of the following properties: Simple construction, low thermal conduction, high thermal inertia, lack of vibrational noise when cooling, isostatic structural behavior, high natural frequency response, adjustable position, vacuum-suitability, reliability, and non-magnetic. Additionally, the presented cold plate design is low-cost and can be easily replicated. Experimental tests showed that a temperature of at least -190 °C can be reached on the top surface of the cold plate with an LN2 consumption of 10 liters and a minimum vibration frequency of 115 Hz, which is high enough for most vibration tests of space components.
On the nonlinear hunting stability of a high-speed train bogie
(Springer, 2023-02) Bustos Caballero, Alejandro; Tomas-Rodriguez, Maria; Rubio Alonso, Higinio; Castejón Sisamón, Cristina; Ministerio de Ciencia e Innovación (España)
The hunting phenomenon is an intrinsic swaying motion appearing in railway vehicles due to the vehicle's forward speed and the wheel-rail contact forces. Hunting motion consists of wheelset and other vehicle's components oscillations that arise above a certain vehicle's speed known as critical or hunting speed. These oscillations are of unstable nature and represent a safety hazard as they could lead to the vehicle's derailment. This article analyses the stability of a bogie nonlinear model for a Spanish high-speed train when this is travelling at speeds near the hunting speed. The vehicle's stability is studied by means of root loci methods, and the value of the critical speed is found. In addition to this, the behaviour of the vehicle is studied in both stable and unstable regions and the existence of limit cycles is discussed in this work. Finally, a sensitivity analysis of the axle load and suspension parameters is performed. The results show that the axle load, the vertical stiffness of the primary suspension and the lateral damping of the secondary suspension have a significant influence on the value of the critical speed.
Optimal selection of the mother wavelet in WPT analysis and its influence in cracked railway axles detection
(MDPI, 2023-04) Zamorano Garzón, Marta; Gómez García, María Jesús; Castejón Sisamón, Cristina; Ministerio de Ciencia e Innovación (España)
The detection of cracked railway axles by processing vibratory signals measured during operation is the focus of this study. The rotodynamic theory is applied to this specific purpose but, in practice and for real systems, there is no consensus on applying the results obtained from theory. Finding reliable patterns that change during operation would have advantages over other currently applied methods, such as non-destructive testing (NDT) techniques, because data between inspections would be obtained during operation. Vibratory signal processing techniques in the time-frequency domain, such as wavelet packet transform (WPT), have proved to be reliable to obtain patterns. The aim of this work is to develop a methodology to select the optimal function associated with the WPT, the mother wavelet (MW), and to find diagnostic patterns for cracked railway axle detection. In previous related works, the Daubechies 6 MW was commonly used for all speed/load conditions and defects. In this work, it was found that the Symlet 9 MW works better, so a comparative study was carried out with both functions, and it was observed that the success rates obtained with Daubechies 6 are improved when using Symlet 9. Specifically, defects above 16.6% of the shaft diameter were reliably detected, with no false alarms. To validate the proposed methodology, experimental vibratory signals of a healthy scaled railway axle were obtained and then the same axle was tested with a transverse crack located close to a section change (where this type of defect typically appears) for nine different crack depths.
Data preprocessing for vibration analysis: Application in indirect monitoring of ship centrifuge lube oil separation systems
(MDPI, 2022-09) Zamorano Garzón, Marta; Avila, Deivis; Nicolas Marichal, Graciliano; Castejón Sisamón, Cristina; Ministerio de Ciencia e Innovación (España)
Air quality can be affected by merchant ships, so it is important to regulate emissions that are produced, as well as to use energy efficiently. In this sense, the cleanliness of the oil used in lubrication is essential to achieve a better use of energy and reduce losses in marine engines. For that, it is vital to carry out good maintenance strategies. Therefore, it is important to develop techniques that allow condition monitoring during engine operation. In order to detect potential problems as soon as possible, it is common to analyze vibratory signals, since sustainable changes in the rotating frequency and its harmonics can be detected, which was the objective of this work, by analyzing the time-frequency domain using wavelet packet transform. A methodology to select the optimal function (mother wavelet) and the best patterns to monitor, in order to determine the state of the purifiers of the marine lube oils, was carried out, including intelligent classification systems. Specifically, this document considers centrifugal oil lubricant separators systems, since the monitoring of these systems can determine the condition of different mechanical systems.
Forward and inverse dynamics of the Biped PASIBOT
(SAGE, 2014-07) Corral Abad, Eduardo; Meneses Alonso, Jesús; Castejón Sisamón, Cristina; García Prada, Juan Carlos
This article addresses the supporting foot slippage of the biped robot PASIBOT and develops its forward and inverse dynamics for simple and double support phases. To address the slippage phenomenon, we consider an additional degree of freedom at the supporting foot and also distinguish between static and kinetic friction conditions. The inverse and forward dynamics, accounting for support foot slippage, are encoded in MATLAB. The algorithm predicts the motion of the biped from the torque function given by the biped's sole motor. Thus, the algorithm becomes an indispensable tool for studying transient states of the biped (for example, the torques required for starting and braking), as well as defining the conditions that prevent or control slippage. Since the developed code is parametric, its output can greatly assist in the design, optimization and control of PASIBOT and similar biped robots. The topology, kinematics and inverse dynamics of the one-degree-of-freedom biped PASIBOT have been previously described, but without regard to slippage between the supporting foot and the ground.
New stopping criteria for crack detection during fatigue tests of railway axles
(Elsevier, 2015-10-01) Gómez García, María Jesús; Castejón Sisamón, Cristina; García Prada, Juan Carlos; European Commission
There are several EN standards that regulate railway axles design, manufacturing, and maintenance since axles are one of the most important elements in a railway vehicle in terms of safety. Fatigue tests are included in the standards, and they are widely used in this area to verify whether fatigue limits surpass certain specified values. Fatigue tests can be performed using test machines in which the axle rotates or more frequently, using Sincotec resonance test machines. For both types of test machines, fatigue tests aim to check if a crack appears in an axle within 107107 loading cycles, thus it is necessary to establish stopping criteria in case a crack appears during the test. In the case of resonance test machines, the axle is determined to have been cracked when the testing frequency drops more than 0.5 Hz. For rotating axle tests, there are alarm levels for the displacement of the center of the axle, axle temperature, and variation of the load applied. However, in both cases, stopping criteria have shown low sensitivity to cracks: when the machine stops, defects are very large. Thus, testing can involve a waste of energy and time, and risk of catastrophic failure of the axle, which raises safety concerns and could lead to serious damage of the machine and its environment. This paper addresses a new methodology based on vibration measurements to establish more precise stopping criteria for crack detection during fatigue testing of railway axles. The use of one of the latest developments of the wavelet transform, the Wavelet Packets Transform, allows a crack to be detected many cycles before the conventional methods. The methodology has been successfully applied to a machine where the axle rotates, with very promising results.
Evaluation of Time and Frequency Condition Indicators from Vibration Signals for Crack Detection in Railway Axles
(MDPI, 2020-06-25) Sánchez, René Vinicio; Lucero, Pablo; Macancela, Jean Carlo; Rubio Alonso, Higinio; Cerrada, Mariela; Cabrera, Diego; Castejón Sisamón, Cristina; Ministerio de Economía y Competitividad (España)
Railway safety is a matter of importance as a single failure can involve risks associated with economic and human losses. The early fault detection in railway axles and other railway parts represents a broad field of research that is currently under study. In the present work, the problem of the early crack detection in railway axles is addressed through condition-based monitoring, with the evaluation of several condition indicators of vibration signals on time and frequency domains. To achieve this goal, we applied two different approaches: in the first approach, we evaluate only the vibrations signals captured by accelerometers placed along the longitudinal direction and, in the second approach, a data fusion technique at the condition indicator level was conducted, evaluating six accelerometers by merging the indicator conditions according to the sensor placement. In both cases, a total of 54 condition indicators per vibration signal was calculated and selecting the best features by applying the Mean Decrease Accuracy method of Random Forest. Finally, we test the best indicators with a K-Nearest Neighbor classifier. For the data collection, a real bogie test bench has been used to simulate crack faults on the railway axles, and vibration signals from both the left and right sides of the axle were measured. The results not only show the performance of condition indicators in different domains, but also show that the fusion of condition indicators works well together to detect a crack fault in railway axles.
New support roller profile design for railway wheel re-profiling process by under-floor lathes with a single cutting tool
(Springer Science and Business Media LLC, 2022-01-07) Corral Abad, Eduardo; Meneses Alonso, Jesús; Gómez García, María Jesús; Castejón Sisamón, Cristina; García Prada, Juan Carlos
The wheel re-profiling is an important part of railway wheelset maintenance. Researchers and railway operators have been very concerned about how to minimize the loss of time during wheel re-profiling without decreasing safety. Avoiding wheelset disassembly means considerable time savings, while reducing wheel damage during operation. Underfloor wheel lathes are the most appropriate tool to achieve this double objective, and therefore the most used nowadays. Multi-cut tool lathes have the disadvantage of being extremely expensive. On the other hand, with single tool lathes, re-profiling is not smooth or safe enough when current convex profile support rollers are used. It is well known by the companies that during reprofiling the wheel suffers impacts/damaged. In this article, a methodology to optimize the profile of the support rollers used in underfloor single tool lathes for railway wheel re-profiling is proposed. This novel profile design will minimize damage and increase the safety of such lathes, since it proposes a greater smoothness in the process. Simulations of re-profiling process have been carried out by the finite element method showing that the designed roller profile reduces drastically the impact/damage during the operation. The impact generated between the re-profiling wheel and the rollers is avoided. Profile-optimized support rollers have been used in a real underfloor wheel lathe, showing good results.
Predictive Suspension Algorithm for Land Vehicles over Deterministic Topography
(MDPI AG, 2022-05) Bustos Caballero, Alejandro; Meneses Alonso, Jesús; Rubio Alonso, Higinio; Soriano Heras, Enrique; Ministerio de Ciencia e Innovación (España)
A good suspension system is mandatory for ensuring stability, comfort and safety in land vehicles; therefore, advanced semi and fully active suspension systems have been developed along with their associated management strategies to overcome the limitations of passive suspensions. This paper presents a suspension algorithm for land vehicles traveling through a deterministic topography. The kinematics of a half-vehicle model and the algorithm are implemented in Simulink. The algorithm’s inputs are the measurements provided by a position scanner located on the front wheel of the vehicle. Based on this input, the algorithm reconstructs the topography in real-time and sends the corresponding command to an actuator located on the rear wheel to compensate for the irregularities of the terrain. The actuation is governed by the parameter “D”, which represents the distance over which the algorithm averages the height of the terrain. Two ground profiles were tested and sensitivity analysis of the parameter “D” was performed. Results show that larger values of “D” usually yield less vibration on the actuated mass, but this value also depends on the irregularities of the terrain.
Modelling multiple-simultaneous impact problems with a nonlinear smooth approach: pool/billiard application
(Springer Nature Ltd., 2022-02) Gismeros Moreno, Raúl; Corral Abad, Eduardo; Meneses Alonso, Jesus; Gómez García, María Jesús; Castejón Sisamón, Cristina; Comunidad de Madrid; Universidad Carlos III de Madrid
Smooth approaches are able to model reasonably well contact/impact events between two bodies, showing some peculiarities when dealing with certain geometries and arising certain issues with the detection of the initial instant of contact. The characterization of multiple-simultaneous interaction systems, considering (or not) energy dissipation phenomena (mainly friction), is always an interesting research topic, addressed from different perspectives. In the present work, the process of design, optimization and verification of a multiple-impact, day-to-day multibody novel model is shown. Specifically, we have decided to focus on a pool/billiard game due to its geometry simplicity. The model involves several balls moving freely and rolling, suffering different kinds of contacts/impacts among them and against the cushions and the cloth. In this system, the proper modelling of both contact and friction forces in the multiple, simultaneous contacts and impacts events is critical to obtain consistent results. In addition, these forces are complicated to model because of its nonlinear behaviour. The different existing approaches when dealing with multiple-contact events are briefly described, along with their most distinctive features. Then, the interactions identified on the model are implemented using several nonlinear contact-force models, following a smooth-based approach and considering friction phenomena, aiming at determining the most suitable set of both contact and friction force models for each of these implemented interactions, which take place simultaneously, thus resulting in a complex system with multiple impacts. Subsequently, the solving method that provides the most accurate results at the minimum computational cost is determined by testing a simple shot. Finally, the different interactions on the model are verified using experimental results and previous works. One of the main goals of this work is to show the some of the issues that arise when dealing with multiple-simultaneous impact multibody systems from a smooth-contact approach, and how researchers can deal with them.
Condition monitoring of critical mechanical elements through Graphical Representation of State Configurations and Chromogram of Bands of Frequency
(Elsevier, 2019-03) Bustos Caballero, Alejandro; Rubio Alonso, Higinio; Castejón Sisamón, Cristina; García Prada, Juan Carlos; Ministerio de Economía y Competitividad (España)
Fault detection is a crucial aspect to avoid catastrophic failures on mechanical systems, as well as to save money for companies. Currently, a number of non-destructing tests, signal processing analysis and artificial intelligence techniques are used for processing larger and larger amounts of maintenance data in all industry fields, either independently or combined. This manuscript presents a novel methodology for the condition monitoring of machinery, based on vibration analysis. The methodology is supported on two novel signal processing techniques: Graphical Representation of State Configurations (GRSC) and Chromogram of Bands of Frequency (CBF). These two new techniques apply basic concepts of the machine deterioration theory to the frequency spectrum. In order to prove the successful of the work presented, the methodology is tested against two real examples: vibration signals from the Case Western Reserve University (CWRU) Bearing Data Centre, and vibration signals from a high-speed train in normal operation. The results show that these new techniques can process large amounts of data without using artificial intelligence, identify adequately the operating condition of the tested systems and give precise information about that operating system by means of simple graphs and colours.
Methodology for the integration of a high-speed train in Maintenance 4.0
(Oxford University Press, 2021-12) Bustos Caballero, Alejandro; Rubio Alonso, Higinio; Soriano Heras, Enrique; Castejón Sisamón, Cristina; Ministerio de Ciencia, Innovación y Universidades (España)
The fourth industrial revolution is changing the way industries face their problems, including maintenance. The railway industry is moving to adopt this new industry model. The new trains are designed, manufactured, and maintained following an Industry 4.0 methodology, but most of the current trains in operation were not designed with this technological philosophy, so they must be adapted to it. In this paper, a new methodology for adapting a high-speed train to Industry 4.0 is proposed. That way, a train manufactured before this new paradigm can seize the advantages of Maintenance 4.0. This methodology is based on four stages (physical system, digital twin, information and communication technology infrastructure, and diagnosis) that comprise the required processes to digitalize a railway vehicle and that share information between them. The characteristics that the data acquisition and communication systems must fulfil are described, as well as the original signal processing techniques developed for analysing vibration signals. These techniques allow processing experimental data both in real time and deferred, according to actual maintenance requirements. The methodology is applied to determine the operating condition of a high-speed bogie by combining the signal processing of actual vibration measurements taken during the normal train operation and the data obtained from simulations of the digital twin. The combination of both (experimental data and simulations) allows establishing characteristic indicators that correspond to the normal running of the train and indicators that would correspond to anomalies in the behaviour of the train.
Enhancement of chromatographic spectral technique applied to a high-speed train
(Wiley, 2021-12) Bustos Caballero, Alejandro; Rubio Alonso, Higinio; Castejón Sisamón, Cristina; García Prada, Juan Carlos; Ministerio de Economía y Competitividad (España)
High-speed rail is a key player in people's mobility thanks to its speed and high safety standards. These high safety standards are supported by extensive maintenance (of both rolling stock and track) that applies the latest nondestructive and monitoring techniques. In that context, this work presents the enhanced graphical representation of state configurations (EGRSC) and enhanced chromogram of bands of frequency (ECBF) methods, which are the evolution of the graphical representation of State configurations and chromogram of bands of frequency techniques. A clearer nomenclature is defined for the configuration states of the EGRSC. The ECBF introduces a new variable threshold that allows discarding frequency regions with small power variations and a new color palette. These methods are used in the vibratory study of an in-service high-speed train to identify the operating condition of the train. To conduct that task, a set of accelerometers is installed on the axle box of a trailer axle of the train. Accelerometers are oriented into the three space directions: longitudinal, lateral, and vertical. Vibration signals are taken during the normal operation of the train and transmitted to and stored on a remote database. Vibration measures are collected before and after a major maintenance operation. The application of EGRSC and ECBF allows collecting information from thousands of vibration signals and to display that information intuitively and understandably. The analysis of EGRSC and ECBF results allows identifying several frequency regions with significant spectral power variations that are common to the three vibration directions studied. These patterns should be taken as a reference for future maintenance actions. Any unexpected behavior of these frequency regions would indicate the presence of a fault.
Improving the learning of engineering students with interactive teaching applications
(Wiley, 2021-11) Corral Abad, Eduardo; Gómez García, María Jesús; Díez Jiménez, Efrén; Moreno-Marcos, Pedro Manuel; Castejón Sisamón, Cristina
Over decades, Mechanical Engineering students often find some difficulties to grasp some contents and/or struggle with some parts of the course. With the increasing development of new technologies, promising innovations can be implemented enhancing learning and improving success rates. In this study, a new learning interactive method is proposed and evaluated using the experience of over 600 students of Mechanical Engineering. This study describes a 4-year experiment based on new interactive applications for education. The experiment has been implemented using E-learning techniques and new technologies (a combination of remote and virtual examples, videos, quizzes, and theory). Specifically, several applications have been programmed to be executed on different devices, such as mobile phones and PC/laptops (Android and Windows). The experiment is applied using small applications that help the students identify the most challenging contents and guide them throughout step-by-step. The main objective of this interactive method is to help students find their lack of knowledge and offer them contents to cover it. These didactic applications are portable and intuitive. Thanks to these interactive applications, it is possible to accomplish better practices of “E-learning” and “Computer Simulation and Animation” together. Since they are portable applications, they allow the student to interact and check conceptual understandings at any place. Students really appreciate this aspect. The results of the course titled Mechanism and Machine Theory have been analyzed during these four last years in which these interactive applications have been offered to the students.
Mathematical analysis of the process forces effect on collet chuck holders
(MDPI, 2021-03-01) Soriano Heras, Enrique; Rubio Alonso, Higinio; Bustos Caballero, Alejandro; Castejón Sisamón, Cristina
Chuck holders are widely used for jobs with high precision. A chuck holder consists of a nut with a tapered surface and a thin-slotted clamping sleeve typically made of hardened steel and named a collet. Chuck holders are, essentially, wedge mechanisms. In this paper, we investigated the reactions and strains due to the forces during the chip removal process in the contact elements or jaws of the collet by means of mathematical analysis. Deflections in the jaws of the collet arise with a high influence from the precision of the workpieces. The cutting or process forces cause an axial force, a radial force, a torsional moment, and a bending moment on the chuck collet, and, consequently, displacements and inclinations of the clamping system are caused. Therefore, the proposed analytical models are based on elasticity and contact theories. The mathematical model for determining the deflections of the clamping system force was developed and implemented using MATLAB. The results showed that the variation in the clamping force during rotation in a collet chuck holder mainly depends on the stiffness of the collet chuck holder and the stiffness of the workpiece. The results indicated that the collet should be vulcanized to minimize the deformations that affect the final product. The deflections of a collet chuck holder due to process forces depend strongly on the clearances, wedge angle, and stiffness of the collet.
Wavelet packets transform processing and genetic neuro-fuzzy classification to detect faulty bearings
(SAGE journals, 2019-08-12) Hernández, Ángela; Castejón Sisamón, Cristina; García Prada, Juan Carlos; Padrón, Isidro; Nicolas Marichal, Graciliano; Ministerio de Economía y Competitividad (España)
A great investment is made in maintenance of machinery in any industry. A big percentage of this is spent both in workers and in materials in order to prevent potential issues with said devices. In order to avoid unnecessary expenses, this article presents an intelligent method to detect incipient faults. Particularly, this study focuses on bearings due to the fact that they are the mechanical elements that are most likely to break down. In this article, the proposed method is tested with data collected from a quasi-real industrial machine, which allows for the measurement of the behaviour of faulty bearings with incipient defects. In a second phase, the vibrations obtained from healthy and defective pieces are processed with a multiresolution analysis with the purpose of extracting the most interesting characteristics. Particularly, a Wavelet Packets Transform processing is carried out. Finally, these parameters are used as Genetic Neuro-Fuzzy inputs; this way, once it has been trained, it will indicate whether the analyzed mechanical element is faulty or not.

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