What Leonardo da Vinci machine was designed to move under its own power?

Leonardo da Vinci designed a self-propelled cart, a spring-powered vehicle that could move without being pushed by a person or pulled by an animal. He drew the mechanism in the late fifteenth century, probably around 1478 to 1480.

Large coiled springs supplied the energy, while a system of gears transferred that force to the wheels. Adjustable mechanisms could control the cart's route, making it suitable for a theatrical performance or ceremonial display rather than ordinary transport.

The cart is sometimes called a Renaissance robot because it could perform a programmed movement. It was not an automobile in the modern sense: it had no engine, steering wheel, or passenger cabin. Reconstructions have shown that the basic mechanism can work when built from the surviving drawings.