What Leonardo da Vinci device was designed to move itself using springs and gears?

Leonardo da Vinci designed a self-propelled cart powered by springs and gears.

The cart, drawn around 1478 to 1480, is often described as an early ancestor of the automobile or robot. Wound springs supplied energy, while a system of gears controlled the wheels. A steering mechanism could make the cart follow a predetermined path.

Leonardo may have intended the device for theatrical performances or court entertainments rather than transportation. It was not an engine-powered vehicle, and its short operating range would have limited practical use.

Modern reconstructions have demonstrated that versions of the design can move. The cart is distinct from Leonardo's mechanical lion and mechanical knight, which were separate automaton projects.