By probing at the PES(position error signal) and look at the frequency under power spectrum analysis, I tried to understand how to relate the frequency observed to the source of resonance. Understand that resonance could be contributed by motor, head, windage, VCM, environment, is there anyway to figure out or further evaluate the source of the noise?

In a nutshell : you want to see if you can find a motor/VCM/mechanical problem by analising the PES signal ?

I will give you some pointers.
Whilst not exactly implementing your research, Zhimin et al. look at the problem from a different perspective.(which is always useful, as is the list of references).. .good luck it sounds an interesting project.

DOI: 10.1016/j.jsv.2007.09.042
Zhimin, H., Chunling, D., Jianqiang, M. & Eng, H.O. (2008) Reducing position error signal (PES) due to disk vibration using an air shroud. Journal of Sound and Vibration, 311(3-5), 874 - 885.


Personally I would not have performed the experiment this way , since it does not correctly simulate the drive enclosure.

You might also consider using the additional sources of "voltage"/"current" measurements to further enhance your research.(possible non-rotation? )

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Yes... that is correct. Any clue?

Where to get the source on the material you suggest? Is it a free copy?

The way of probing PES from the HDD board will keep the whole drive intact, so that is the way I am looking for.

Nothing can replace visual and mechanical analysis. Only in few case you can pinpoint the problem.
Ah, BTW, in theory it is correct, but to perform what you want, you need access to PES data and know also how servo is configured. So all this is useless , it's only theory.
Every drive brand / family have different servo structure and there is also adaptives that play a role.

Hi,
The material "may" be available on the internet from "other" sources, I cannot post the article because it is keyed to my personal library
I guess with the title you should be able to easily find a secondary source, but if you contact the author directly and ask nicely, usually they will send you a copy.

With the DOI , it will point you to the reference material and an introduction.

The text is interesting because it gives an in-depth review of reducing induced noise/vibration onto the PES system.(this may be an insight into evaluating the suitability of using it)

dig about on the following databases :

Science Direct
ACM
Springerlink

Also if you 'dig' around in the world patent database , there is lots of interesting material on this subject area.

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