Up Camera Calibration
Posted: Thu Sep 06, 2018 6:00 pm
Recently I found my up camera calibration was off and causing placement problems on parts that were rotated.
While re-calibrating this camera using the "ruler and camera-box" method as described in the instructions, I got to wondering if there was a more accurate way. I am curious if my new method is an improvement or if there is an error in my thinking.
With the present software, the only thing the up facing camera is used for is to measure the wobble of the nozzles. So I put the smallest nozzle on and centered it in the cross-hairs of the up-camera in the down position. This X,Y position is then the base/reference point for the up-camera also used as the nominal value.
Then I jogged the nozzle to the upper right corner of the up camer's box. This gives me a measure in millimeters of both the x & y dimensions of the box. So just subtract the base value from the coordinates and double the result.
This seems to me to be more accurate for a couple of reasons. First, it is measuring the box size at the correct distance from the camera (the same distance that will be used when measuring wobble), so the magnification is the most accurate. Secondly, it is much easier to measure these small distances with the help of the camera's optical image.
Comments ?
While re-calibrating this camera using the "ruler and camera-box" method as described in the instructions, I got to wondering if there was a more accurate way. I am curious if my new method is an improvement or if there is an error in my thinking.
With the present software, the only thing the up facing camera is used for is to measure the wobble of the nozzles. So I put the smallest nozzle on and centered it in the cross-hairs of the up-camera in the down position. This X,Y position is then the base/reference point for the up-camera also used as the nominal value.
Then I jogged the nozzle to the upper right corner of the up camer's box. This gives me a measure in millimeters of both the x & y dimensions of the box. So just subtract the base value from the coordinates and double the result.
This seems to me to be more accurate for a couple of reasons. First, it is measuring the box size at the correct distance from the camera (the same distance that will be used when measuring wobble), so the magnification is the most accurate. Secondly, it is much easier to measure these small distances with the help of the camera's optical image.
Comments ?