Re: Drag coefficient of 2012 Game Piece
 

Alright, well if we go the way of a look up table, is there some way you can put a "line of best fit" equation to the data points, but using three variables, x,y, AND z for distance angle and exit velocity. Just get all of your data points then fit a equation to it? Does anyone know of any software or method to do this? Or is it even possible? (As I am not too fimilar with 3-Dimentional graphing)?

This way, the robot can plug in ANY distance and pick an angle that gives a good entry angle to the basket, then get a initial velocity back.

Re: Drag coefficient of 2012 Game Piece
 

This is what we've done for the most part. We have a program that takes an angle and tells you the hang time, ball velocity as it leaves the launcher, and the entrance angle to the hoop. We then took that and did some logic to determine that the steepest angle entrance angle to the hoop with the shortest hang time within the capabilities of the robot is likely the best shot. It seems to produce excellent results but it's tough to say for sure. We're adding code to plot the results next to see if visibly they look good.

Honestly, now that we have this simulation running I'm waiting for one of you pros to produce a really good equation for ball trajectory that takes into account drag and I'll toss it in there to see if it produces better results.

I'm not sure how much farther to take it though as I gather most everyone on my team thinks the better approach is to build the robot and fire a million shots through it to calibrate what it can do. I don't disagree with that approach but I do feel the math is very helpful is us understanding what velocities and angles are appropriate, etc.

Re: Drag coefficient of 2012 Game Piece
 

I didn't read most of the thread, but as for the original query -

Air resistance for this piece is close to negligible. For a regular basketball, it would be negligible, but the mass of this game piece is a bit light, so air resistance may play some role. If so, you merely need to increase the initial velocity slightly. Because Air resistance decreases time in the air when the movement is horizontal in 3D space, while increasing time in the air when moving vertically downward in 3D space.

So you should use simple kinematics of projectile motion and fine-tune it by adding a small number to the initial velocity.