Science Buddies: "Ask an Expert"

Is creating an active vibration control system with piezoelectric materials from scratch plausible in the realm of a high school project? I'm working in a high school environment , so I won't have much access to advanced equipment usually in labs...If it seems like a reasonable idea, can anyone offer any elementary papers or links for a starting point?
Thanks in advance!

I would think that there are several possible experiments that you could design in this area that would be challenging but within the reach of a motivated high school student. You probably would want to keep it pretty simple, perhaps based on a speaker coil to create the vibration in a controlled environment. Piezo actuators have very short travel ranges, and so they aren't good for damping large amplitude vibrations such as you might find in a car or large scale device. The real trick is going to be figuring out how to measure the vibration in a way that can be input to either an electronic circuit or a computer (depending on what your interest and aptitude is), calibrating it to figure out the delay in the control loop, and then actuating the piezo to counter the vibration.

This sounds like a very interesting project to me.

gsjbjt,

I notice that your due date is 11/24/12. A complete vibration control system is likely to take longer to develop, so be sure to choose a simple project that you can finish in time.

WW

Thanks for your informative replies! How long would you estimate is the proper time frame to comfortably finish constructing the system? I'm pretty sure the time frame will not be too restrictive as I can extend it by a month or two as needed.

Would a object whose vibration is being driven (like the speaker coil you mentioned, Mr. Trent) be able to be fully stopped by the piezo actuator? I haven't worked with these hands-on before so I'm not sure what their displacement/force capabilities are. I'm currently trying to detail the experimental setup and running into some confusion--must the actuator be separate but periodically coming into contact with the object as it vibrates, or somehow attached directly to the surface? I imagine that the actuator was fully bound, the whole thing would just vibrate as a unit and the piezo would be exerting some useless force without actually stopping the vibration. Is my understanding of this somehow flawed?

Thanks again!

gsjbjt,

I don't know how much time you have to work on your project nor how fast you can learn and apply. Nevertheless, I think several months would be required to build an effective antivibration system from scratch.

Here are a couple of points to note.

A piezoelectric device generally works best at very high audible to ultrasonic frequencies. If the device you want to control vibrates at lower frequencies, the piezoelectric device is not the best choice to counteract it. Magnetic devices like loudspeakers would be a better choice.

The device that you use to counteract the vibration needs to be attached to the vibrating device as tightly as possible. Even with tight coupling you will likely need an electronic circuit to sense the vibration, compute how to counteract it, and drive the counteracting device at just the right force to reduce the overall vibration.

I think you need to read a bit about vibration control and the fundamental technologies used to implement it. Unfortunately, a quick web search didn't find any articles that were helpful, and suitable books listed on Amazon are quite expensive. If you want to do a more complete search, try phrases like "Active vibration control," or "adaptive control filter."

You can search the Google Scholar database for academic articles. You will find quite a lot of articles on active vibration control. Many of these articles may be too mathematically advanced for you, and you usually have to pay to see the articles. Your local library might be able to obtain the articles for you.

Good luck, WW