Angle Calculation from image of goal

[Jared Russell]

Originally Posted by pipsqueaker

Could you elaborate more on what trig you'd need to use? I've been wondering about this, and it seems to me that the angle the camera is mounted at should only affect the y coordinate, and since the angle calculation only takes x coordinates the mount angle shouldn't affect the result.

I will try to post a more detailed explanation tonight, but for now: it affects both coordinates.

Imagine a camera that is looking straight up. What does the x coordinate mean with respect to the robot? What does the y coordinate mean?

[Camilo86]

We actually took the time to do the trig out for the offset. You can take a look at our function https://github.com/FRC125/NU16/blob/...lator.java#L31 you will just need to now the fov, dimensions of image, height of camera, x,y offset of camera in inches and angle of the camera.

Your offset basically changes based on the distance to the target. You use the y coordinate of the target to calculate this distance.

[cjl2625]

Originally Posted by Rflax40

Basically it is giving out smaller angles than it should right now. Would the camera being offset ~2 inches from our center of rotation be enough to cause these issues?

Our camera is offset ~5" from the shooter wheel and we don't have that problem. If you're using a calculation that uses the camera's field of view, try increasing the value for the field of view until you get angles that look better. (that's what I did, anyway)

The horizontal field of view that you'd find on the camera's data sheet doesn't always agree perfectly with the observed results; it might take a bit of experimental tweaking.

[Rflax40]

Originally Posted by Jared Russell

I will try to post a more detailed explanation tonight, but for now: it affects both coordinates.

Imagine a camera that is looking straight up. What does the x coordinate mean with respect to the robot? What does the y coordinate mean?

I'm not sure this holds true when working with a "flat" image, we just tried rotating the camera and it did not change the x value of the target