What self-propelled device did Leonardo da Vinci design for theatrical movement around 1490?

Leonardo da Vinci designed a self-propelled cart around 1490.

The compact vehicle used coiled springs to store energy, with gears and mechanisms transferring that energy to the wheels. Its steering could be set in advance, allowing the cart to follow a programmed path rather than being driven continuously by a person.

The cart is often associated with theatrical spectacles at Renaissance courts. It may have been intended to move on its own during performances or ceremonies, although the exact original purpose is not certain. Leonardo’s surviving drawings do not provide a complete modern construction manual.

A full-scale reconstruction made in the early 21st century demonstrated that the basic mechanism could work. The cart is sometimes called an early robot, but it was a programmable mechanical vehicle, not an autonomous machine in the modern electronic sense.