Very high speed real-time image detect and process.

[yijing fu]

hi, my problem is:
I need to use CCD camera to detect the motion of a laser beam spot, with possible oscillate frequency arround 5k or a bit lower.
Since i donot need the whole frame captured by the CCD camera and the frame speed will be much lower than that. Is that possible that i can build a system like that with IMAQ board and progressive scan CCD camera?

[BruceAmmons]

Yijing,

I don't really understand what you are trying to accomplish. I need more information to answer your questions.

What are you trying to detect or measure? Do you want to know the frequency and amplitude of the motion? Do you just want to know if it is moving? Is the laser beam shining on a target, or directly into the camera? Will it always oscillate on a single axis, or is the direction random?

If you want to measure the frequency, you need to sample at about 10kHz, which is too fast for most area cameras. If it is oscillating on a fixed axis, you could do it with a line scan camera. In any case, you will end up using a digital camera with a digital interface (PCI-1422 or 1424).

Bruce

[PdB]

My suggestion has nothing to do with a vision solution (if vision is a camera, a board and software).
Can't you use one of those optical sensors with 4 or more sectors? Their application is mainly in aiming or alingment use, but you could connect the 4 optical sensor-area's (via some electronics/) to a daq-board.
You will have no info on the actual position, but you know when the spot leaves a particular area, thus you will know the frequency and something on the way the spot travels.
It's just an idea.

[Ben]

Hi Viling,

I agree with the other posts that this is too fast for a vision solution.

If I understand what you are trying to do, then I have been involved in two groups that have done similar work.

In both cases a "split-photodiode" was used as the sensing device.

In one application, the output was monitored by a lock-in amplifier do to the high frequency of the "Carrier" (we where interested in the FM component of the signal Note: This scheme was developed by Dr. Jeremy Levy of the University of Pittsburgh, the inventor of Aperatureless Near-field Scanning Optical Microscopy ANSOM ). In the other case, a standard DAQ card was able to monitor the signal.

I hope this gives you some ideas,

Ben