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Unread 04-02-2007, 18:28
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Re: Distance to travel once targetted?

For one reason or another the distance we were getting using tangent was close (within a couple feet) but not nearly accurate enough. This could be due to significant figures in many different variables (we tried multiple times to make it as accurate as possible).

Does anyone have any say on this?

For now we are using the tilt angle as the indicator at how close we are to the actual light.
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Unread 04-02-2007, 19:26
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Re: Distance to travel once targetted?

Quote:
Originally Posted by Mitch View Post
For one reason or another the distance we were getting using tangent was close (within a couple feet) but not nearly accurate enough. This could be due to significant figures in many different variables (we tried multiple times to make it as accurate as possible).

Does anyone have any say on this?

For now we are using the tilt angle as the indicator at how close we are to the actual light.
One suggestion would be to mount the camera as low as possible. Also, have a look at this posting for a suggestion.

-Kevin
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Unread 07-02-2007, 09:38
baclaskya baclaskya is offline
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Re: Distance to travel once targetted?

Thanks Kevin. This looks great. I'd like to try and make similar adjustments to our camera. However, I'm not sure about the terms that you are using and how they apply to control the pwm outputs. Is there a document that describes the function of pwm outputs (ie. gain, pulse width, etc.) and how servo motors respond to them? I'd like to get a better picture of how the gain of 70 and calculated pulse width of 2.389 combine to control the camera tilt to reach 90 degrees. Thanks again.
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Unread 07-02-2007, 11:42
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Re: Distance to travel once targetted?

Quote:
Originally Posted by baclaskya View Post
Thanks Kevin. This looks great. I'd like to try and make similar adjustments to our camera. However, I'm not sure about the terms that you are using and how they apply to control the pwm outputs. Is there a document that describes the function of pwm outputs (ie. gain, pulse width, etc.) and how servo motors respond to them? I'd like to get a better picture of how the gain of 70 and calculated pulse width of 2.389 combine to control the camera tilt to reach 90 degrees. Thanks again.
Heres a quick introduction to servos. The center and gain values are in units of 100 ns, so a gain of 70 means the pulse width will increase (or decrease) by 7.0 us for each count above (or below) 127. The absolute pulse width at 127 is defined by the center value, which is nominally 15000, or 1.5 ms.

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