Tears of the Kingdom
"A Zonai device that automatically heads for monsters. It's believed to have been used by the Zonai as a security measure."
Homing Cart is a type of Zonai Device. When activated, they slowly aim for any enemy within their range - adding an attacking Zonai device, such as a Shock Emitter or Cannon, or other offensive article such as spikes, can turn this into an automatic weapon. Mayachideg Shrine ("Proving Grounds: The Hunt") serves as a tutorial in their use, where Link can beat all the constructs within the shrine using only homing carts with spiked metal plates and assorted zonai devices attached as weapons.
As with all Zonai devices, they can be found in Zonai Capsules from Device Dispensers or Treasure Chests; or lying around in the overworld. If removed from a capsule, they cannot be returned to it, although they can be fused to weapons or shields.