[gnunes]

Yes, drag is complicated, but also important. If your launcher spins the ball, then lift is important too.

If you don't want this complication, then your best approach is empirical. Get a lot of data on distance vs. your launch parameters and make a table. Then, the robot can use interpolation to work the other way: given a distance, it can get values for the launch parameters. If you are varying two things (launch angle and ball velocity), then this could get complicated. You will have several tables, and will need an algorithm to determine which one to use.

Even though I wrote the trajectory calculator, our team is going to use the interpolation approach!