ABSTRACT

A laser-based contact less displacement measurement system is used for data acquisition to analyze the mechanical vibrations exhibited by vibrating structures and machines. The analysis of these vibrations requires a number of signal processing operations which include the determination of the system conditions through a classification of various observed vibration signatures and the detection of changes in the vibration signature in order to identify possible trends. This information is also combined with the physical characteristics and contextual data (operating mode, etc.) of the system under surveillance to allow the evaluation of certain characteristics like fatigue, abnormal stress, life span, etc., resulting in a high level classification of mechanical behaviors and structural faults according to the type of application.

Smart sensors or latest generation sensors are now use for vibration measurements. Where the first generation sensors are piezoelectric accelerometers, second generation sensors are modification of piezoelectric accelerometers and latest are the smart sensors. Third-generation smart sensors use mixed mode analogue and digital operations to perform simple unidirectional communication with the condition monitoring equipment.

INTRODUCTION

The study of vibrations generated by mechanical structures and electrical machines are very important. The advent of machines and processes that are more and more complex and the ever increasing exploitation and production costs have favored the emergence of several application fields requiring vibration analysis. Among these application fields, we find machine monitoring, modal analysis, quality control, and environment tests. These functions are used in fields such as aeronautics, space industry, automotive industry, energy production, civil engineering, and audio equipment.

The signal processing application described here uses a laser-based vibrometer in order to analyze the vibrations exhibited by mechanical systems. This technique can be used in the numerous applications mentioned above. The problem is to develop an intelligent system that has the ability to determine the system conditions based on a classification of the possible vibration signatures, detect changes in the vibration signature, and analyze their trends.

The classification of the various possible vibration signatures requires a priori knowledge of the mechanical system under healthy conditions as well as for the various fault conditions; when possible a mathematical model of the system should be provided. The latter is often crucial for the good interpretation of the observations, since it predicts the dynamic behavior of the structure and thus the healthy vibration signature.

Vibration spectra are in general “peaky” due to either the periodic nature of the system’s excitation or to the natural resonance properties of the mechanical system. Changes in a vibration signal can result from a variation of the amplitude, frequency, and/or phase of one or many of the components. Moreover, new peaks may add to the existing spectrum, or some peaks may fade out. Changes can also appear in the form of short transients or spikes in the time domain. At the extreme, if the vibrations become so strong that the structure actually starts to move, then the overall average level of vibration would change, that is, a DC component would appear.

All of the above changes may occur gradually, like fatigue stress slowly deteriorating the material’s properties, or they may occur suddenly, like the rupture of a mechanical part within a machine. They may also occur periodically or in a random fashion depending on the process generating the vibrations. For multiple state systems, changes must be interpreted carefully. For example, if the operating speed of a rotating machine is raised from A to B, the vibration analysis system should not declare the observed changes as being the result of a mechanical failure, but should adapt itself to this new mode of operation.

Download Seminar Report On Mechanical Vibration Analysis.doc

Now the Engineering Seminars Portal or http://techalone.com is fully functional. Now we started uploading the Site with new seminar topics.Here we provide free download feature also for your favorite seminars.We are basically focusing on different streams of engineering like mechanical,computer ,electronics, electrical,civil ,Information Technology and Instrumentation engineering,MCA,BCA etc.We will include basic science seminars soon. However you can also see a few of the Engineering Seminar Topics from the link given below.

ENGINEERING SEMINARS

An Augmented Reality system supplements the real world with virtual (computer-generated) objects that appear to coexist in the same space as the real world. While many researchers broaden the definition of AR beyond this vision, we can generally find Augmented Reality system to have the following properties:
1) Combines real and virtual objects in a real environment;
2) Runs interactively, and in real time;
3) Aligns real and virtual objects with each other.
Augment Reality can be thought of as a “middle ground” between Virtual Environment (completely synthetic) & Tele-presence (completely real).
Augmented Reality Vs Virtual Reality VR was defined as a “computer generated interactive 3-D environment in which a person is immersed”. The user is completely immersed in an aartificial world & is divorced from the real environment.VR – Strives For Totally Immersive Environment.AR – Augmenting Real World Scenes.

Real Desk with Virtual Lamp and Two Virtual Chairs

• It shows a real desk with a real phone.
• Inside this room are also a virtual lamp and two virtual chairs.
• objects are combined in 3-D, so that the virtual lamp covers the real table, and the real table covers parts of the two virtual chairs

Milgram’s Reality Virtuality Continuum

Taxonomy for Mixed Reality
Reproduction Fidelity
Extent To Present Metaphor
Extent To World Knowledge

Characteristics of Augmented Reality

• Augmentation
• Optical vs. Visual
• Focus and Contrast
• Portability
• Comparison Against Virtual Environments

Application of Augmented Reality

1. Medical
1.1 Virtual fetus inside womb of pregnant patient.
1.2 Mockup of tumor biopsy.
2. Military Training
2.1 Two Views Of A Combined Augmented Reality Virtual System
3. Maintenance & Repair
3.1 Prototype laser printer maintenance application, displaying how to remove the paper tray
3.2 Printer maintenance application
4. Robot and Telerobotics
4.1 Virtual lines show a planned motion of a robot arm.

CONCLUSION

Augmented Reality is far behind VE in maturity. The first deployed HMD-based Augmented Reality systems will probably be in the application of aircraft-manufacturing. For example, Boeing has made several trial runs with workers using a prototype system but has not yet made any deployment decisions. The next generation of combat aircraft will have Helmet – Mounted Signals with graphics registered to targets in the environment. These displays combined with short – range steerable missiles that can shoot at target off-boresight, give a tremendous combat advantage to pilots in dogfight. One area where a break-through is required is tracking an HMD outdoors at the accuracy required by Augmented Reality. If this is achieved several interesting applications will become possible.

Techalone has many categories for the Seminar topics, especially for the Engineering Seminars. Civil Engineering is one of our popular catagory. You will get a lot of Civil Engineering related topics and Civil Engineering Seminars from our Techalone. It will also include the topics from the Transportation Engineering, Construction Engineering, Structural Engineering, Environmental Engineering, Survayig, Hydraulic, etc…

You will get a lot of Civil Engineering topics from the link given below also.

Civil Engineering Seminar Topics

ENGINEERING SEMINARS

Techalone.com contains the Seminars Paper Presentation Topics from the different Engineering Branches like the Mechanical Seminar Topics, Electrical Seminar Topics, Electronics Seminar Topics, Civil Engineering Seminar Topics, Computer Seminar Topics, IT Seminar Topics, Chemical Engineering Seminar Topics, Instrumentation Engineering Seminar Topics, Communication Engineering Seminar Topics, etc… This Seminar Topics Website will also discuss with the other Technical Topics like the Engineering Project Topics, New Technology and also the other latest Technical Topics, Latest Technology news and the Technical related news. This Technical Seminar Topics Website has a subsidiary Website called Techalone.blogspot.com. This Website is also discussing with the latest seminar topics and all the other Technical Topics. And also we are looking for the suggestions and comments for our Online Seminar Portal.

The Information We Collect

The Information We Collect

We use statcounter, google analytics and other hosting service tools to collect the information. This includes internet protocol (IP) addresses, browser type, internet service provider (ISP), referring/exit pages, platform type, date/time stamp, and number of clicks to analyze trends, administer the site, track user’s movement in the aggregate, and gather broad demographic information for aggregate use. IP addresses, etc. are not linked to personally identifiable information. The name and website URl are displayed on comments, but email address is secure with us. We do not share it with outside parties

Cookies

Cookies

A cookie is a piece of data stored on the user’s computer tied to information about the user. Our site don’t use cookies. However, Some of our business partners use cookies on our site (for example, advertisers). However, we have no access to or control over these cookies, once we have given permission for them to set cookies for advertising.

Google’s use of the DART cookie enables it to serve ads to you based on your visit to this site and other sites on the Internet. You may opt out of the use of the DART cookie by visiting the Google ad and content network privacy policy.

Newsletter

Newsletter

If a user wishes to subscribe to our newsletter (powered by Feedburner), we ask for contact information such as name and email address. Out of respect for our users privacy we provide a way to opt-out of these communications.

Links

This

Copy Limitations

Please don’t copy the whole post. A short paragraph with content in quotes is acceptable with a link-back to the post at techalone.com

Credit the Source

You need to clearly highlight the fact that the content was derived from techalone.com

Link Back

You need to link back to the article from which you derived the excerpt.

Advertisers

We use outside ad companies to display ads on our site. These ads may contain cookies and are collected by our ad companies, and we do not have access to this information. We work with the ad companies: Google Adsense,

Kontera,Infolinks,chitika, Adbrite etc. Please check their websites for respective privacy policies.

Contact Information

If users have any questions or suggestions regarding our privacy policy, please Contact us.