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Affichage des articles dont le libellé est Reliability. Afficher tous les articles
Affichage des articles dont le libellé est Reliability. Afficher tous les articles

Experts systems and artificial intelligence applied to interpretation and diagnosis in complex mechatronics systems

Hi everybody, as you know I am Electronics engineer with a strong background in control systems, instrumentation and industrial automation and also I am finishing my masters degree in mechanical engineering, you know I love the mechatronics engineering and their role in the actual technical world, 
today I want to show you some of the results that I found in my masters thesis project called, "Design, implementation and evaluation of a expert systems applied for failure analysis in mechanical elements" (Axis, gears, bearings and boilers), in that thesis project I´m comparing three different inference engines as a artificial intelligence strategy for diagnosis and interpretation:

The finish document is here http://www.bdigital.unal.edu.co/45143/
And here there is a paper (you can download for free the pdf for the next 50 days) about this work published in the engineering failure analysis journal Science direct.
http://www.sciencedirect.com/science/article/pii/S1350630715001089

1. Clasic inference engine: based in modus tollens and modus ponens rules.
2. Fuzzy inference engine: Based on a previous comparation between sugeno and mamdani inference engines.
3. Bayesian inference engine, based on bayesian networks.

The system that I developed for axis has got 4 modules:Fracture, corrosion, wear and plastic modules.

Acordding to the different test that I did, I am very surprised because the bayesian inference engine have been the better behavior compares with the clasic and fuzzy inference engine, is amazing how the system solves complex cases of interpretation of evidence in many failure analysis process, Im  using a lot of failure analysis cases from the National University of Colombia (AFIS group have been resolved cases for many industries like Oil & gas, automotive and complex heavy industries).

At the end of my thesis ,probably 2 months, :)I will post the final results, this research project also could be implemented in other engineering fileds (instrumentation, automation and control systems) with amazing results.

I think that in the near future the applied cibernetics as artificial intelligence will be the win ticket for many companies thart spend a lot of money and time designing experts systems for their engineering optimization, honestly I think that artificial intelligence is the future for those industries.

Do you want to see a print screen of my system?

1. An example of bayesian network just for fracture module in axis:


2. Take a look around of the wear module, few questions are necesary to identify the failure mode, based in the knowledge base:  


3. After of the analysis according to the evidence for example for adhesive failure wear mode the system shows the following fault three analysis FTA.(for more information of FTA analsysis read the certified realiability engineer handbook)



The GUI was developed using Matlab/Simulink GUIDE (Bayesian and fuzzy) and C#+Amzi! Prolog (clasic inference). The work has been hard.

The most interesting result in this research masters project is the integration of a lot of my passions in one project as Electronics engineering, mechanical engineering, software develop and control systems, maintenance and reliability knowledge...

Some Oil & Gas companies are interested to implement this system in those industries for interpretation and diagnosis in their specific process (alarm management, Safety Instrumentation systems, control systems), I will be waiting for new challenges :)


Failure is not an option

During my last training and research in failure analysis and reliability engineering program, I found a material from Case Western Reserve University (Mechanical and aerospace department),in this case is a failure analysis podcast... the podcast has got the following description:

"Methods and procedures for determining the basic causes of failures in structures and components. Recognition of fractures and excessive deformations in terms of their nature and origin. Development and full characterization of fractures. Legal ethical, and professional aspects of failures from service."

I think that is an interesting material, due you could to learn any where with this podcast, so I want to give you the link for this interesting podcast.
http://itunes.apple.com/us/itunes-u/emse-511-failure-analysis/id386066906

The picture is just for fun, when I was in Space Center Houston I read a shirt with the message, always I remember it...

Enjoy the podcast.

Rgds.

Articles | 10 Things You Can Do Right Now To Improve Reliability | ReliabilityWeb.com: A Culture of Reliability

Articles | 10 Things You Can Do Right Now To Improve Reliability | ReliabilityWeb.com: A Culture of Reliability

The certified reliability engineer handbook

Today I will recommend you the following book The Certified Reliability Engineer Handbook.

Reliability engineers are professionals who understand the principles of performance evaluation and prediction to improve product/systems safety, reliability, and maintainability. This handbook’s chapters and sections match the Body of Knowledge (BOK) specified for ASQ’s Reliability Engineer certification, which includes design review and control; prediction, estimation, and apportionment methodology; failure mode effects and analysis; the planning, operation, and analysis of reliability testing and field failures, including mathematical modeling; understanding human factors in reliability; and the ability to develop and administer reliability information systems for failure analysis, design and performance improvement, and reliability program management over the entire product life cycle.

http://www.asq.org/quality-press/display-item/index.html?item=H1304

Right now I'm reading this book and I think is a good choise whom loves the maintenance and reliability engineering.

Interaccion entre ingenieria de confiabilidad e ingenieria de calidad

Leyendo un material de la AMERICAN SOCIETY FOR QUALITY especificamente dirigido a ingenieros que se quiere certificar como CERTIFIED RELIABILITY ENGINEER (CRE), encontre algunos items interesantisimos con respecto a la interaccion entre la calidad y la confiabilidad que quiero compartir con ustedes.

Lo que escribire a continuacion es un pequeño resumen de los puntos 2
que me parecieron interesantes.

1. Otra forma de ver diferencias e interacciones entre calidad y confiabilidad, es la forma como los datos son recolectados.
En el caso de la manufactura los datos para ingenieria de calidad son recolectados generalmente en el proceso de manufactura. Entradas como voltajes, temperaturas, parametros de material y salidas como dimensiones, PH, peso y niveles de contaminacion son medidos.

Mientras que la ingenieria de confiabilidad adquiere datos generalmente despues de que el producto fue producido, por ejemplo, el el numero de toggles (cambio de off y on en un interruptor) antes de que este falle.

2. Los ingenieros de calidad y confiabilidad proporcionan diferentes entradas dentro del proceso de diseño de un producto. Los ingenieros de calidad sugieren cambios que permitiran que el producto pueda ser producido entre la tolerancia requerida y a un costo razonable, mientras que los ingenieros de confiabilidad hacen recomendaciones que permitiran que ese item o funcion, opere correctamente por un largo periodo de tiempo.
---


Es algo basico, un producto que cumple con estandares de calidad, generalmente es confiable , la ingenieria de mantenimiento y confiabilidad son geniales.. las garantias, las pruebas... todo!!!

La certificacion como ingeniero de confiabilidad es muy interesante, aunque en mi caso estoy en la busqueda y preparacion de la certificacion como CMRP (certified maintenance and reliability professional) de la SMRP que desde mi corta experiencia es la que cumple con las mayores expectativas que tengo.

Espero que esta entrada les sirva para algo, nos vemos.

Distribucion Exponencial e ing. de confiabilidad

Hoy quisiera compartir un ejercicio clasico de confiabilidad , pero antes, recordemos que cuando la tasa de fallo es constante la distribucion a usar es la exponencial ,pero cuando la tasa de fallo no es constante se utilizaran modelos diferentes como el de weibull del cual tambien mostrare un ejemplo mas adelante.


Una compañía del sector industrial durante el último año ha recopilado los datos de fallas de 50 motores habiendo fallado 2 de ellos durante el periodo mencionado. Nuestra tarea consiste en reprogramar el mantenimiento de manera tal que se satisfagan las necesidades operativas de la compañía, pero para eso queremos saber:

  1. La tasa de fallos.
  2. La probabilidad de falla que tiene un motor antes de alcanzar un tiempo de funcionamiento de 4 meses.
  3. La probabilidad de que un motor este en funcionamiento al cabo de 6 meses.

Ahora veamos como se solucionarían cada uno de los ítems.


Desarrollo.

1. Tasa de fallo: Relación de elementos que presentaron falla sobre el total de elementos, para este ejemplo seria



2. Recordemos que una definición básica de confiabilidad R(t) es: probabilidad de que un sistema, subsistema o elemento del mismo opere satisfactoriamente dentro de un tiempo definido, como se busca es la probabilidad de falla entonces se debe encontrar la infiabilidad F(t) (opuesto a la confiabilidad) su expresión es:

F(t)=1-R(t)

Reemplazando R(t) por su expresion matematica para esta distribucion queda





Resultando así que la probabilidad de falla antes del 4 es del 1.324%


3. Hallamos la confiabilidad R(t) teniendo en cuenta que seis meses es 1/2 años


Por lo cual se puede decir que la probabilidad de que un motor no se dañe antes de 6 meses es del 98%


Con estos datos el departamento de mantenimiento podria fijar con mas criterio el cronograma de mantenimiento para la sección de motores, sabiendo aproximadamente cual es el tiempo de buen funcionamiento o falla de los mismos.