servo doesn't reacts for small increment
Hi...i like to ask about my problem regarding to the servo..i used PSC to position the servo, however the servo doen't move·if i changed the value a little bit (i.e. from 760 to 766)..since i need high precision, a small change will be significant...
Comments
is what causes this. In other words an acceptable margin of error from servo to servo. Sometimes this can be minimized
by over shooting the desired position and then backing up, but with this method you should be aware that consistency is very
important. What I mean is that through out the full travel of the servo, you should always overshoot in the same direction
by the same amount, and then backtrack by the same amount as well. This effectively takes up any slack that might be
mechanically linked with the servo. There are "high(er) precision" servos that will give you what you want, but first you must
define how much precision will meet your needs.
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
For your information, i use GWS servos (SO4 BBM)...in my project, i built a custom-made pan-tilt mechanism with a camera on top of it...this camera will be used to tracked a desired object...the program that i built will command to servo to pan the camera step-by-step until the centroid of the object is at the center of the field of view of the camera (with tolerence up to two pixels)...due to limited budget, i don't think that i can afford for more sophisticated and accurate servo...
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Chris Savage
Parallax Tech Support
csavage@parallax.com
trying to do. It might be better to use a stepper motor with a gear reduction to get your desired resolution OR a continuous rotation servo with a gear reduction.
Either way you will need an external mechanism such as a wheel encoder for determining position.
As something to compare to... With this project, the best resolution that I could get with a beam distance of only 9ft on the opposite wall is about 1cm
http://forums.parallax.com/showthread.php?p=549166
To obtain a two pixel resolution at any distance with a hobby servo without any kind of gear reduction would be next to impossible.
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
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·1+1=10
thinking ahead, what will happen next