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Laser Scanner
Anonymous |
16 year
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Hey all
I am currently working on a laser scanner module to map the local enviroment and was wondering if you guys could help me improve the system. I am using Logitech Fusion Webcam. During processing I can only achieve about 6 fps in Roborealm which generally makes the data less accurate and the laser servo has to be run at a slower speed. Is there anyway to improve the frame rate with this camera? (rated at max 30fps i think) I have tried faster CPU's but this is not the problem.
Also i am using a Hi-tec HS-422 servo to move the laserline.
I am using a VBscript extension to increment the servo variable.
What functions are their in vbscript that would help with this, such as a timer function or something? I have already tried one off the link in the documantation page but I couldn't get it to work.
I also tried using the image-count variable as a time reference. This works fine but over a distace of ~500mm, but the servo makes the line unaccurate and slightly jerky. The servo has an accuracy of 0.075deg.
Any feedback would be helpful
Cheers
Toby
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Anonymous |
16 year
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Toby,
Can you include your current robofile so that we can take a look at where the delay might be?
What servo controller are you using? Sometimes the com to the controller is what causes the slowdown. Knowing the controller we can check that the module is functioning correctly.
6 fps does sound very slow. We should be able to improve that performance.
STeven.
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Anonymous |
16 year
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Hi STeven,
The max fps is 6 even when there are no modules used. It seems to be something in the way data is received from Logitech Fusion Webcam. It is connected through USB2.
Do you have any ideas on the issue?
Cheers
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Anonymous |
16 year
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Do you have directX installed? Are you selecting the DirectX driver from Options->Video? It is the one WITHOUT Vfw in the name.
Can you try the camera in a very bright lighting situation?
What resolution are you running the camera in?
Try covering the preview of the camera image and just watch the fps. Does it go up? If so then your graphic card cannot keep up.
STeven.
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Frame rate issues
from Australia [87 posts] |
16 year
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Hi STeven,
Here is the debugging.
"Are you selecting the DirectX driver from Options->Video? It is the one WITHOUT Vfw in the name."
Only options I have under Video are:
Logitech QuickCam Fusion
and Microsoft WDM Image Capture (Win32)
So I selected Logitech QuickCam Fusion
"Can you try the camera in a very bright lighting situation?"
In very bright lighting conditions the frame rate went up from 6 to 14.6 fps for 960x720 pixels. And the frame rate went up from 6 to 25.5 fps for 640x480 pixels.
I don't get it. Why does the frame rate get limited to six for low lighting conditions?
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Anonymous |
16 year
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The lower the light level the longer it takes for the CCD pixel to get enough light to trigger a capture. Thus once the light level decreases the CCD timer will increase in an attempt to compensate. Others have seen this issue to with other cameras. Some have even forced the camera to return a very dark image and then use the Color Balance module to bring the colors back out again. While this does increase frame rate the image quality is never as good as just waiting for the CCD to finish.
Best way around this is to increase the light levels. :-(
STeven.
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from Australia [87 posts] |
16 year
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STeven,
I cannot change the Logitech Fusion exposure time, probably because it is CMOS. Is there a way to specify the integration (acquisition) time. When I go to Video Capture > Advanced, the Automatic Gain Control is grayed out and I cannot vary the Exposure or Gain.
Is there a way to do this?
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Anonymous |
16 year
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Does your interface look like the one below? We have the Fusion and it does seem to allow for this change. By adjusting that we can improve the low light frame rate. Perhaps you have an older model?
STeven.
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from Australia [87 posts] |
16 year
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Not quiet the same.
Here is my one.
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from Australia [87 posts] |
16 year
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Hi Steven,
I got my Logitech Fusion camera few months ago. If you think that it is an older model, can you recommend a newer model as I thought that this one was. Just a web link or anything, so that I can recognize the right one.
Thanks heaps.
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Anonymous |
16 year
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Hmm, that is strange ... we got ours probably a year ago. So I would imagine that if you bought yours new in the last few months that it would have been the newer model.
I suppose your QuickCam program also has that interface disabled? See ours below.
On the label ours reads
M/N: V-UAR33
P/N: 861196-0000
PID: LN54087
If this info is different perhaps you will need to contact Logitech and ask why the exposure settings are not enabled. This comes from the DirectX interface with the camera (so also be sure you have the most recent version of DirectX) or try to download the latest drivers for that camera. Nevertheless, this is beyond our scope of knowledge with that camera ...
STeven.
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from United States [214 posts] |
16 year
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Hi Toby and STeven,
I use a Logitech Fusion and a Quickcam 5000 quite a bit. On my Logitech control panel (shown in the image), you have to turn off "Right-Light" before you can turn off "Automatic Settings" and manually change the exposure. So look for a "Right-Light" or "Right-Light 2" check box on the one of the screens and make sure this is un-checked. On my control panel, the "Right-LIght" check box is on a different tab/screen than the "Automatic Settings" check box.
--patrick
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from United States [214 posts] |
16 year
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Ooops--I captured the wrong screen from the control panel. Here is the correct one.
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from Australia [87 posts] |
16 year
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That's brilliant! It works. It's going 30 fps instead of 6.
Thanks to both of you (STeven and Patrick).
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from United States [214 posts] |
16 year
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Excellent! Glad I could help!
--patrick
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MP CAMERAS
Anonymous |
16 year
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Just an FYI for anyone else reading this thread, these changes also seem to make a large difference using the Logitech MP camera as well!!!
Thanks for the excellent information!
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