Shooter Aiming Methods

[stingray27]

For vision processing, I believe I am going to setup a system that uses vision processing, but at a minimal level. Last year, we wrote some code to attempt and follow the targets at all times. This didn't seem to fit to the game and so this year we are going to revise that method. The labview code for vision targeting from last year is a really good reference for those of you trying to figure it out. The only change you have to make is when determining the aspect ratio subscore, you have to compare it to the targets aspect ratio this year instead of the aspect ratio from last year (18 by 24). I am just going to divide the width and the height and then later use that number to determine what target the camera is currently looking at. I can then throw out the aspect ratio subscore when determining if the camera is looking at a target or not and use the other 3 subscores as the determining factor (convex hull operation score, or the rectangle coverage %, and the vetical and horizontal line scores).

As for actually using the vision information, I believe that we may go with just a single button that activates a vertical alignment of the shooter. Since the target is so wide and just limited in height, the shooter then would line up vertically and then hand over control to the operator. The horizontal alignment would just be from the driver. This allows for just a quick rough alignment of the robot and then the operator would only have to perform quick slight fine tuning.

Any thoughts?

[ctccromer]

Here's my PLANS for this year (final results may vary):

1) Auto-aiming system with a shooting system that does NOT move on a turret or anything. It can aim up/down slightly, but that's the only axis it moves on and only to an extent

2) I'm switching to a controller this year and my very first idea for coding the robot was to not only make the joysticks turn and move the robot, but also code it so that while I have the left trigger held down, make the joysticks turn and move the robot at 0.25 normal speed. This way you don't have to JUUUUUST BARELY NUDGE the turning joystick a bunch of times to line up the shot -- you can manually aim the whole ROBOT (not the shooter on a turret) at the goal, then use an algorithm to aim the shooter's motor speed and vertical height, NOT horizontal angle

[fb39ca4]

Last year, we had a slow mode button on our controller as well.

[falconmaster]

We had a great deal of success last year by locating landmarks on the field and then lining up with them and then launching the balls. We think we can do the same this year. To assist us though we are going to use a "photon cannon" aka flashlight http://www.amazon.com/8066-T6-Rechar...ts+1000+lumens
Like the three days robot builders guys. From our experience this is much faster and more reliable than computer vision processing. There are too many variables to account for that a human can adapt to that a computer without an extensive vision processing program can do as well or fast. Just my two cents...

[stingray27]

For anyone wanting a explanation of what the example code for vision processing is doing, I put up a youtube video here: https://www.youtube.com/watch?v=m2Pwdq30eSI last year where I explained to my mentor what it was doing. Please bear with it as it is toned down, slow and probably all not incorrect (and long). But I have gotten some good feedback in that my explanation made a lot of sense to even non-programmers. Check it out if your interested.

[jesusrambo]

Our plan for this year is to have extensive auto-targeting to align the turret on the fly as we move, but with only movable elevation. Azimuth will be handled by actual driving, though we're planning on having that automatically align too. The image processing will be offloaded to the driver station, though we're looking into using an onboard computer.

[PhantomPhyxer]

Originally Posted by nathan_hui

Decreasing the speed of the shooter will decrease the range of the frisbee. As to what it will do to the accuracy, that will require testing of a different sort. We initially used a table and a pool noodle to test shooting - different amounts of accelaration cause different ranges

Aiming at the goals will most likely be done via manual aim (the targets are large enough). Auto aim is doable, but may not be of any advantage (you're driving towards the darned thing, might as well take the time to slew the turret). Not sure about range, but then we were thinking of raising the shooter, so there's that too.

I did not know there were other former Tanker on this site. The "Slew" term related to Turrets makes me think there are. I worked on the Bradley Fighting Vehicle several years. We used an aim able Turret last year.

[ttldomination]

Originally Posted by androb4

I would like to know if anyone is thinking about making a turret or having a variable angle shooter, like last year.

What would be your method of aiming at the goals?

Also, will just lowering the speed of the shooter wheel, decrease the range or trajectory of the frisbee? Has anyone done any testing with this?

(1) A turret is feasible, but I don't think it's necessary. We're still grappling with the adjustable angle. We're trying to find the sweet angle.

(2) We're determined that if we can do a full-ish auto aim that the driver is comfortable with, then we'll go there. In the mean time, we'll just be looking for that sweet spot for manual aim.

(3) We have done some preliminary testing, and what you have said seems to follow, however, we will do more testing in round two to back up what you have said.

- Sunny G.

[gabrielau23]

Two words:
Photon Cannon

[Mongai]

After dedicating a week of design time to a turret last year and hardly using it, we immediately crossed out that idea. Something along the principles of K.I.S.S. (Keep It Simple Stupid)

[mdrouillard]

We plan in auto to aim the whole robot.