[Kruuzr]

One method that does not rely on the size of the blobs is to calibrate your robot so that it knows the distance using the y-offset of the target. The closer you are, the higher the blobs are in the image. You need to be consistent as to which color data you are getting the info from (such as always the bottom one). We will be calibrating ours by setting out a tape measure and moving the target trailer right next to the robot. Record the y-offset. Move the target 3-4 inches (whatever resolution you want) and record the y-offset again. Keep going until you have the makings of a look-up table. Our tests at about 10 feet gave us 2-3 inch distance resolution.

Steve C