an earthquake seismograph

[aemre]

hi... i am a new user of edaboard.com...so i don t know that here is the truest part for this request...i have to do a project.. that is seismograph....it has 3 vibration sensers..for example in a room,we will put the sensers to the corners of room...and electronic circuit will measure the distance of shake,to the sensers with microcontroler...so by this way we will find the shock centre...but now we coludn t find the electronic circuit or software for microcontroler...and i don t have enough time...i need this...if you can t understand,because of my english,you can send mail to me... from aemretasdemir@hotmail.com i give you much info...thank you very much...

 

[mupd]

I think you have a problem. I used to be an earthquake seismologist and did something like this in the mid 70s. Talk man-years of effort. You have a scaling problem too if you want to do it in a room not country-wide. In my case a few km of precision was ok and I did it with an MC6802, you would need 10^4 higher speed - that means a 40 GHz DSP! Do the physics calculations first to roughly assess the feasability of your project.
Mike

 

[echo47]

This sounds like a student lab project, so maybe he doesn't mean "earthquake" as in the planet Earth. Maybe he wants to locate a person stamping his foot on the floor.

 

[artem]

As far as i understand (i am amateur in seismics) ) the basic principle is about microcontrollers have to be time synchronised so when earth quake (what ever producing mechanical signal) signal will be received the time for the signal will be catched and if signal propagation speed is known it is possible to get distance to center where it is happened. Or may be distance calculation is based on earthequake signal streght ?

I dont think that there is need for 40 GHz if data is to be catched into ring buffer and processing starts at detection of signal. Mechanical vibration propagation in earth does not have high speed and vibration frequency are located in infrasonic frequency spectr . As this link says (dot know whether it is right or not **broken link removed**):
"... the speed of a horizontal wave-like vibration starting from a centre and spreading in ellipsoid circles of vibration generally at 5 to 7 geographical miles per minute."That means wave propagation speed is about 266 meters per second and to get at least 1 meter resolution we will need 266 Hz sampling of data . I do not refer to complex calculation for vibration processing but to input data rate .

What is needed : some vibration sensors , normalizaing circuit - amplifier with wide input signal dynamic range , may be with some kind of compression, detection logic implemented on software, one mcu ( PC for tests wil be OK) with 3 input switched adc capable of sampling rate up to few dozens of kilosamples per second.

mupd, I dont know method used for scientific calculations , may be you can explain or give some references .

 

[Tohu]

Hi,
you have a problem, but not with the cpu speed, the problem is dinamic range, several years agoo i start project with one university, then we can contract the price, but i start the research, different specialist have a different point of view about the dinamic range. But the final requariments was be for a 24 chanel 24bits resolution. The frecuency is not very High, 1000 is more that enought, the real input frequency is not highest that 20 Hz. But ADC with true 24 bits resolution is a very difficult to find. ........my plane take off .. i will write leter.

 

[MichelM]

you can see

h**p://www.infiltec.com/seismo/

 

[unmonje]

to do software need time and you dont have.
Sorry.

 

[buntheun]

hi
i know u want to protect ur room u can make it so easy !!!