Monday, December 20, 2010

Vibration Engineer and the Body

I am constantly in awe of the beauty and design of our human body. It never ever fails to surprise me. It tells me almost everything I need to know for my survival and sense-making of the world around me. 

It tells us when we need food. It never fails to tell us when we need love and when we must get up from bed and when we must go to sleep. It informs us of our deepest emotions and feelings and what is going on in our minds and in the mind of others and it tells us what to do and when is the best time to do it. It is a fine piece of instrument cleverly designed over million of years. It deserves a lot of respect and care since it would continue to serve us well only if we care to listen to it and train it.

The design is surprisingly simple. We have 6 senses that connect the outside to the inside. These, which we call inward senses, are sight, touch, hearing, smell, taste and feeling. These senses are all connected to the mind for sense making, processing and action. For action we have 5 outward senses, which are -- move, eliminate, grasp/hold, express and create. In total, we then have, 11 senses and one mind to work with. It is as simple as that. But it creates a world of difference once we learn how to use them effectively. 

What do we often say about the highest class of musicians like Ravi Shankar or artists like Hussain or dancers like Birju Maharaj? We say that they feel their art in their bodies and expresses their art through it. Similarly, good vibration engineers also feel their subject through their bodies and mind. Let us see how the mind-body helps a vibration engineer to develop that great feeling for the subject and makes him/her effective forever. 

Our bones (while in the body) are piezo-electric crystals. Hence they act as accelerometers, which are effective vibration transducers. So, when we receive a shock or a vibration from the surroundings we can immediately feel it. We feel vibrations all over our body. 

We feel the low frequency vibrations (less than 10,000 Cycles Per Minute or CPM) in the lower part of the body (navel downwards right up to the toes).

We feel the medium frequency vibration (10,000 CPM to around 45,000 CPM)  in the middle part of the body (navel up to the shoulders)

And the high frequency vibrations (above 45,000 CPM) are felt in the upper part of the body (neck and the head).

So, different parts of the body have filters (high pass and low pass filters a result of neuron networking) to filter out certain frequencies of the vibration. 

Our index finger can feel a vibration of even 10 microns (really small when we compare that to the diameter of our hair which is around 60/70 microns). I find it so useful to detect soft foots by placing the index finger at the junction of the machine's base plates.

The hand especially the palm of the hand is useful in many ways. Each palm is fitted with a number of pressure sensors. A variation in pressure activates these pressure sensors. Hence if there is a variation in vibration (where pressure is dependent on the acceleration) we can immediately sense it through our fingers and hand. It tells us whether only the fundamental is present or it is present along with other significant frequencies and harmonics. These pressure sensors also inform us about the forces and the direction in which they are acting. Fortunately our hands also sense temperature quite well. If we can keep the palm comfortably on something for about 15 seconds we are more or less certain that the temperature is below 40 degrees C. When we do the same with the other side of the palm we can sense temperature up to 60 degrees C. 

What about our ears? That turns out to be very interesting. It naturally does a Fourier Transform for us. The complex sound waves that enter our brains through our ears are split into its various frequency components along with their amplitudes. That is why in a concert we are able to distinguish between the flute and a violin and between a sitar and a tabla (the difference is created by the frequencies). So through our hearing we can sense amplitudes, frequencies, harmonics, vortices, quality of vibration, i.e. presence or absence of damping etc. It is clear that our ears play a vital role in the understanding of vibration. I call this 'playing by the ear'.

Obviously, our eyes are fascinating too. It takes in a large amount of visual data at any instant of time enabling our brains to process them to make sense of what is going on. But one thing is striking about it. Our vision is sharp and clear at around 8.8 Hz that translates to 528 cycles per minute (CPM). So our eye senses very accurately a problem with low frequency vibrations that are around 500 to 600 CPM. We are fortunate to be thus tuned. This is because low frequency vibrations are the cause of most problems. It loosens nuts and bolts. We can see base plates jumping around and pipelines, ducts and structures vibrating. This has really come to my rescue a number of times. It helped me to understand the source of a problem even before I took vibration measurements or poured over the details of the vibration data that were collected. We can even make a sense of the amount of damping in a system and sense heat transfer mechanisms.  

Of course it is easy to understand that we don't use taste as a tool for understanding vibrations but we do use smell a lot. It tells us about the effect of vibrations on parts of the system. It generally informs us of the after effects of vibration -- we smell the oil, we smell burning, we smell too much friction etc -- most of which are the after effects of vibrations.

What do we do after we have analyzed the vibration patterns? We either 'move' things around like balancing or aligning. Or we 'eliminate' defective parts. Or 'create' better designs. Or modify the structures or tighten loose parts to 'hold' the vibrations. And lastly teach others about what we have learned ('express' our feelings). By teaching others we actually reinforce our own learning for life. Very few realize this great secret and the best secret of learning. It is so cleverly embodied in our Indian saying -- the more you give the more you learn. Knowledge is the only thing in the world that increases with sharing. 

No wonder that visual data taken through all our senses and the mind make up more than 90% of what we need to 'Feel' and analyze vibration related problems. Instruments only help to enhance or clarify our understanding with some certainty. Nothing more than that. It is also not surprising that any actions that we take are only limited by our 5 outward senses. Hence the mind-body complex is the only thing that we really need to solve any problem. The real secret instrument for analyzing and taking action lies hidden in our 11 senses and one mind.

That is the secret I wanted to share. But what are we doing to train our mind-body complex to be razor sharp for sensing and action whenever we want to act?

Posted via email from systemvibes

No comments: