Usb camera

[euhlmann]

The quick and easy way to align is to just turn until the target is in the center of the frame.
I'm not familiar with GRIP, but there should be a function that gives you the center of the object you are looking at.
Initially we tried using PID for alignment but the inherent issues with our robot's large drive dead zone and the lag in vision processing drove us to ditch pid and do our own two-phase constant rate turn.
First, we turn quickly until the target is within 20% around the center. Then, we turn slowly until we just pass the target and immediately stop there. This results in pretty decent alignment.

Here's some psuedocode for you

slow_zone = 0.2
slow_speed = 0.5
fast_speed = 1
repeat until (error = abs(target_center - image_width / 2)) < acceptable_error
  sign = target_center > image_width / 2 ? -1 : 1 // which direction to turn
  if error < slow_zone
    arcadedrive(0, slow_speed * sign)
  else
    arcadedrive(0, fast_speed * sign)
end

Good luck implementing this!