How do you aim your shooter?

[Salik Syed]

just wondering how are all you other teams plannign to aim your ball shooting mechanism?

[sanddrag]

We have a custom turntable driven by sprocket, chain, and globe motor. It rides on steel and teflon balls. It has about 160 degrees of rotation. On top of the turntable is a tilt mechanism actuated by the van door motor and driven by sprocket and chain. It can go from 0 to 45 degrees.

Of course, all this is just theoretical. We have not even started building it yet.

[Donut]

For control of the rotator, we will be using a joystick to rotate back and forth manually, or will allow the camera to rotate it to face the goal (we have a switch that allows us to change between manual and automatic control). For the speed (we are adjusting speed not angle), we will use a series of 4 push buttons to change a desired speed by small or large intervals for manual control, and the camera will once again change the speed based on automatic control.

Mechanically, the speed control requires nothing extra than what we already had (one of the big CIM motors driving one flywheel), the rotator control will be done using a van door (or window) motor, driven by either a chain-sprocket connection or a belt drive (not sure which).

[Pat234]

We are using the camera linked to a globe motor to control the tilt through a 30 degree range of motion and the pan angle will be controlled through the drive train to line the robot up accordingly. These both will be controlled through the camera while on offense however the drivers will have some capability to override the camera controls.

[kawelch]

Luck and prayer

[Jared Russell]

Complete auto aim.

[Sachiel7]

We plan to allow the possibility of manual control, but we are focusing on having fully automated aiming utilizing the camera, to shoot on the fly.

[Spindash54]

Aim? Who needs to aim? We just hit the fire button and relax...

[bbehnke]

for our angle adjustment we are using a cam (off-set center circle) to move a plate up and own and for yaw we are using a lazy suzan design and a automatic aim from the camera. the only thing manual is when you want to shoot the balls into the goal and winning the game

[Salik Syed]

So it seems many teams ARE going the automated aiming route...

[Ethulin]

Originally Posted by Salik Syed

So it seems many teams ARE going the automated aiming route...

I have a feeling this is going to be VERY similiar to last year with the green tetras. Many teams try it, may teams fail. One team that half/sorta does it!

Our shooter does not aim. No, I am not being dumb, we really do have a shooter and it really does not aim.

[Madison]

Originally Posted by bbehnke

for our angle adjustment we are using a cam (off-set center circle) to move a plate up and own and for yaw we are using a lazy suzan design and a automatic aim from the camera. the only thing manual is when you want to shoot the balls into the goal and winning the game

How do you compensate for the cams varying radius as it moves? The rate at which your pitch changes is never constant.

[Alan Anderson]

Originally Posted by M. Krass

How do you compensate for the cams varying radius as it moves? The rate at which your pitch changes is never constant.

Many things are nonlinear in this system. Camera tilt angle is not proportional to distance. Distance is not proportional to the required pitch angle. Pitch angle can be, but is not necessarily, proportional to the cam position.

Fortunately, the nonlinearities are all irrelevant if you forego detailed computation and just make a simple lookup table that converts the measured camera tilt directly to the desired pitch adjustment. Creating that table is as easy as moving the robot forward and backwards, measuring the camera tilt, and manually tweaking the pitch adjustment until it works the way you want.

[Parker]

[quote=sanddrag] On top of the turntable is a tilt mechanism actuated by the van door motor and driven by sprocket and chain. It can go from 0 to 45 degrees.

You might run into problems shooting close to the center goal with only 0-45 degrees of rotation. If you want to aim at the lower goal just turn down the speed of your shooter.