A common argument as to why scenarios in zombie stories like World War Z and the remake of Dawn of the Dead go to hell as quickly as they do is because people are unwilling to open fire on seemingly unarmed civilians until it is too late, leading to police and military people being overwhelmed and becoming zombies themselves. Unmanned vehicles and robots, on the other hand, even those odds pretty quickly.
Imagine a situation where a town or city, or even a particular building has started with some peculiar behaving people. This is very standard from most zombie-themed entertainment. In WWZ, it was in a town in China, one kid was infected, in the original Dawn of the Dead, an entire apartment building was filled with dead people, and in Resident Evil (the movie, anyway), the lower levels of the Hive complex was filled with hungry corpsey types. Sending people into those situations is a great way to increase the population of walking cadavers by exactly the number of people you sent in.
Now, instead of sending in a SWAT team or some soldiers, imagine instead you roll a few of these in:
The stakes change dramatically when you aren’t putting actual humans in harm’s way.The robots would allow people to really roll right up to the undead and check to see if they are actually dead people or humans. Imagine setting it up with an infrared camera; switch to IR, it’s the same temperature as the room, so we can assume that it’s not Aunt Molly out for a hallway stroll but her reanimated cannibalistic remains, so pop a hole in her head and check the next one. Suddenly, instead of a group of potentially tasty snacks and future zombies, you have a machine (or machines) that will likely go ignored by the walking dead and give you the time to analyze them to ensure that before you decide to start killing them, they are actually the enemy; something a human would likely not have time to do without being at extreme risk.
And that is just one scenario. Drones could be used to patrol the perimeter of the Zombarcology. UAVs provide much the same advantage they do now; the ability to surveil and attack from above without placing any undue risk on human pilots. Imagine if something like the Rage virus from 28 Days Later was infecting the countryside and you have a pilot flying around watching a full-on concert-crowd-sized group of infected when a goose smashes into his windshield and he crashes into the middle of it. Hope to hell he doesn’t have any family, because that is a face-to-face meeting I don’t want to be a part of.
On the other hand, if you are using reaper or a Firescout and it goes down, well it sucks to lose equipment, but at least no one died. Ground-based unmanned vehicles provide you with an even cheaper, easier way of clearing out undead; take a Ripsaw or a Crusher and just start driving it through a crowd of zombies. With the crusher, you would end up with a field of pulped up, smashed dead people, many completely out of commission or broken to the point that they just sit there smelling awful and being scary, but otherwise harmless to all but the most dim-witted.
The Ripsaw would probably shred them to pieces. Just park it on top of a few and gun the engine; the treads would spin out, sending zombie parts every which way. Sure, coating a hillside with infected blood and body parts is a bad idea if there are living people around, but far less of a concern when you are just rolling through the area with robots. Mount one of the vehicles with a flamethrower, or send in a UAV with napalm, and now you have a localized ecological disaster that smells awful, but cleanly cleared out a healthy dose of the walking dead menace.
The Zombarcology would not only feature a fleet of unmanned aerial rotorcraft, but a cavalry of unmanned ground vehicles and robots to patrol the area to keep it secure, and also allow for the rabid rescue of survivors. The US Army has played with the idea of unmanned evacuation robots for this exact scenario; why risk human lives when you can roll in a robot and have them take the risk? You don’t have to worry about a robot succumbing to PTSD or getting infected. Plus, a nice boiling hot shower with bleach should kill any pathogens stuck to the drones, lessening the risk that someone performing maintenance accidentally becomes infected.
Last and certainly not least, small constellations of micro drones could be used to scout for survivors, or actively hunt the undead. Arm them with small silenced guns, and you could take out entire zombie swarms by floating up to them and shooting then right in the head. You could have automated swarms patrolling several square miles around the Arcology, ensuring that they are noticed long before they ever get close enough to be a danger.
The advantages don’t stop with the land and air, however. Submersible drones could be used with Zombarcologies near coasts, lakes and rivers, searching the waters for submerged undead and either terminating them or sending warnings to the air and land based drones to prepare an attack. They could be lowered into wells and watch for any shambling corpses to make sure water supplies aren’t contaminated, or at least warn that they are so that filtering/cleaning efforts can be increased.
Drone boats could stay on the lookout for boats over run with zombies or even snipe ones crawling up on shorelines. If the Zombarcology in question is using a moat, then you have another home for yet another layer of perimeter defense. With a little existing technology, we could easily distance ourselves from the zombies just using existing technology. Also, I call dibs on the idea, so anyone deciding to make this into a video game, i would appreciate at least a shout-out. (I don’t expect a shout-out)