# Robot vision distance sensing & launch tube design

1. Jan 8, 2012

### physicsofme

So, For FIRST FRC robotics, We have made 3 different objectives to research, and I decides to start with the projectile.

We need to launch an 8" diameter foam basketball into a goal that's 18" diameter. We can be anywhere from 3feet to 54 feet away.

We had an idea of using the classic catapult style but then making the stopping point moveable to take the range calculations and compute them with a varying force of the arm.

However, this can be very unreliable in a sense if we want to actually score. Now I've been researching but I just cannot determine this: would pneumatic pistons offer a more precise force with a calculated air pressure instead of a springy force that would be in the catapult that would deteriorate?

As well, are there any other methods of launching this projectile up between 2' and 8'?

2. Jan 8, 2012

### physicsofme

Sensors?

Here is the known facts:

Mounted around 5 foot off of the floor.
"see" objects anywhere from 3 feet to 54 feet away that are anywhere from 2 feet to 8 feet tall.
Will then take a distance feedback and use that information to calculate a needed arch and force to make a basket.

Basically, its a foam basketball shooting robot, but our design team is having problems deciding what sensors we want to put on the robot so that it can pick up "A retro-reflective Vision Target (Reflexite GP020, 50mm; Pro Gaff Tape, “black”, 2 in.) mounted behind each Hoop".

Any ideas on exactly what sensors to use? We were looking at using a time of flight one, but we aren't sure how that would work. Also, could we actually use the time of flight, rotate it to map points in 3D then have an executing algorithmic sequence to determine what we're actually looking at and then shoot? or would that take too much time? Any other sensors you might suggest I research?