Differences with BBB and Galileo/Tre?

Hello everybody. I’m hoping to work on a few Arduino & OpenCV projects with a BBB. I’m hoping to work with some basic robotics in real-time. Is there a big difference between the BBB + an Arduino cape (like Adafruit’s proto cape) and Galileo? They seem to fill a similar niche. Would I have to look towards the Tre to fulfill the real-time requirement?

Hello everybody. I'm hoping to work on a few Arduino & OpenCV projects
with a BBB. I'm hoping to work with some basic robotics in real-time. Is
there a big difference between the BBB + an Arduino cape (like Adafruit's
proto cape) and Galileo?

Huge. BeagleBone Black has more performance alone than Galileo and can do
the real-time stuff using the PRUs eliminating the need for an Arduino cape.

They seem to fill a similar niche. Would I have to look towards the Tre
to fulfill the real-time requirement?

Tre will give you a more familiar programming environment for the real-time
stuff as well as additional analog input support. Tre's power will come
from the simplicity of working with it.