General thoughts, like. This could be land, sea, air, or space.

  • There'd be different classes/sizes of robots.

  • These would be something like a Pareto distribution, with lots of small robots, and few big motherships.

  • After doing some worldbuilding thinking, I concluded 5 classes is perfect (or 4-6 if you don't like being given prescriptions)

So a swarm of 1000 land-based killer-robots might consist of:

827 dog-sized scouts

118 man-sized robots

35 car-sized robotic vehicles

16 robotic tanks

4 lorry-sized carriers

Or in the air:

827 miniature UAVs (to use the military term)

118 medium UAVs 

35 full-sized UAVs like the notorious Predator

16 plane-sized drones

4 cargo planes

The whole point is for big robotic vehicles to carry smaller ones, kinda like this Amazon concept where an airship has quadcopter children. Or imagine a huge haul truck rocking up and 200 robotic humanoid soldiers piling out.

I'm gonna use the terminology 'mother' and 'child' for this.

  • Large vehicles are useful because they have longer range, can carry more powerful antennæ, can carry either payloads or children. Large vehicles don't always have to carry smaller ones; they could be just carrying their own payload. A mission like blowing up a big building would require a big vehicle with its own payload; it can't be done with pesky swarms.

  • Children depend on mothers for long-distance transport in and out of battle, for long-range comms, and for fuel. (For short-range missions, you could get the job done with just small robots.)

AIR

  • Tiny, insect-sized drones are useless and run into engineering problems, validating my thing above about five classes being best: https://en.wikipedia.org/wiki/Micro_air_vehicle

  • Miniature UAVs would be the smallest class in the robot swarm (and would make up the >80% of the robot swarm). This would be something like the AeroVironment Switchblade, which weighs 2.7kg and has a 10km range, or the ZALA Lancet. The AeroVironment Switchblade "attacks at a 115 mph (185 km/h) dash speed" – imagine 1000 of these these armed with blades and AI flying into people like spears (I never said this was nicey worldbuilding)

  • Medium UAVs weighing tens of kilograms, with ranges about 100km, like this, this, this. These could only carry 3-4 miniature UAVs, but that might be very useful for a job like taking out a small team/squad from 100km away.

  • Full-size UAVs are a big tool of real-world warfare in the 21st century. These weigh half a tonne to a few tonnes. Could deploy 200 miniature UAVs or 10-20 medium ones. Most notorious example is the Predator. The Turkish Bayraktar has a 4000km range.

  • The next size up are like planes. I couldn't find many examples of military drones this size, but the Northrop Grumman X-47B can carry a 14 tonne payload at 1000km/h. This could airdrop robotic ground soldiers (robot paratroopers), like 111 man-sized ones or 1000 scouts, enough to capture a town in one drop.

  • The biggest aircraft ever aren't robotic, but could be in worldbuilding if you like. The Airbus A380 has a range of 14,800km, payload 84 tonnes, ceiling 13km, cruise speed 903km/h. That's enough payload to drop 600-700 robot soldiers or about 80 Predator-type drones.

LAND

Could have wheels, legs (hexapod robots are a research area) or treads like a tank.

  • The smallest class I've taken to calling the Scout. The 9kg Dragon Runner runs on treads. The PackBot weighs 14.3kg and can go 9.3km/h. This one can carry a 2.7kg payload. This would make up >80% of the robots in the swarm.

  • The next class up are man-sized (but not necessarily humanoid/bipedal). Some humanoid examples are Atlas and BEAR. The iRobot Warrior weighs 129kg, can carry 227kg, and can go at 15km/h on treads. THeMIS and TALON are in this class too.

  • Then you've got car-sized ones like the Guardium (3m long, weighs 1.4 tonnes, 80km/h) which could be used to deploy smaller robots.

  • Then you've got tank-sized ones like the rIPSAW, Type-X, or SYRANO. These could be on wheels or treads (or hexapods if you want to be weird about it).

  • The largest class is comparable to haul trucks. The 'ultra' class of haul trucks starts at 300 tonnes payload capacity – https://en.wikipedia.org/wiki/Haul_truck – though armour-weight might force that down.

NAVAL and SPACE

I didn't go into detail, but the same principles apply: five classes. Big classes can carry small swarms, In the sea, you have to think about both submarines and surface craft. (The Royal Netherlands Navy has published a report that robo-subs might be useless.

PAYLOADS

  • Percussion/swordlike weapons like the R9X that has done assassinations in Syria.
  • Missiles
  • Armour-piercer: https://en.wikipedia.org/wiki/Kinetic_energy_penetrator
  • Machine gun
  • Laser weapon (1km range max)
  • Nonlethals: microwave heating, loud sound, tear gas, nets
  • Cameras and sensors for a surveillance/recon mission
  • Sniper drones/UAVs have been considered: https://en.wikipedia.org/wiki/Autonomous_Rotorcraft_Sniper_System
  • Bomber plane things

COMMUNICATIONS

  • The robots, big and small, would have pre-shared decryption keys. They would go into battle with a list of targets, and could update the list when their AI recognises something considered an enemy. They gossip this information to any comrades within range (gossip is a computer science term meaning passing on information to neighbours so they build up their computer. If robot A tells robot B some information, robot B then knows that to tell it to every robot it comes into communication with.

  • The information will be kept as small as possible, ideally kilobytes not megabytes. The timestamped GPS location and velocity of a chess piece is less than 100 bytes. Every robot gossips this to every other robot when it establishes a link.

  • Assume communications will be jammed/damaged occasionally. The robots must able to act autonomously then, seeking out evacuation, maybe hunting targets.

  • The small, cheap swarming robots would therefore use low-power wide-area network which has some interesting properties: it can run on just AA batteries for years, has a range of 10km unencumbered, maybe 3-5km with buildings/trees/weather, is light (these robots are small, they can't carry much). The tradeoff is that its bandwidth is shitty, maybe a few kbps. Fun paper on jamming these networks and counterjamming measures here: https://sci-hub.se/10.1109/INFOCOM42981.2021.9488774

  • Occasionally on the battlefield, a robot will come within 30-50m of its comrade. This gives them a chance to establish a WiFi connection. They can now exchange gigabytes of information, not just the positions of chess pieces. Jamming isn't a problem because the enemy is unlikely to have a jamming device within such a small radius. WiFi as we know is light and small; we all carry battery-powered light WiFi transceivers around all day.

  • I haven't given as much thought to the comms of larger classes. Maybe free-space optical communication that it can beam to its children. Maybe 5G small cells. Willing to hear input on this from Hexbear.