I absolutely love the idea of being a general in battle. That is what has always drawn me to Total War games (that sadly I cannot run) and other titles that allow some form of control over another being. Call me a control freak. In Fallout, this involves companions. But what I have always wanted to do, is to be able to turn robots to my side and use them against an enemy.
So for the Robotics Expert Perk I can see:
Rank 1: You deal more damage against robots, and gives you the ability to stealthy disable robots from behind.
Rank 2: Allows the construction of basic turrets to defend your settlements
Rank 3: Allows the construction of simple robotics to defend your caravans
Rank 4: Gives you the ability to sneak up on robots and turn them to your side (not necessarily as companions, just makes them mute to you as a hostile)
Rank 5: Allows the construction of advanced robotics to defend your settlements and caravans and also allows you to upgrade any of your current robots with more advanced weaponry. This includes the upgrading of any of your robotic companions (this may slide into a 6th rank but I have no clue how many ranks on average there will be on some perks).
It is also possible that there will be a separate perk altogether to build new defenses but apparently there are not any more perks than there were in previous games so we won't know until release or before.
Any other robotic related perks anybody can think of? Or if you care to dispute the above one.