What wheeled device did Leonardo da Vinci design to move by itself?

Leonardo da Vinci designed a self-propelled cart that could move without being pushed or pulled by a person or animal.

The cart appears in Leonardo’s engineering studies from the late 15th century. Its motion came from coiled springs, which stored mechanical energy and released it through a system of gears. Cams helped control the wheels and determine how far the cart traveled. The design is often described as an early programmable machine because its movement could be set in advance.

The cart was probably intended for theatrical or ceremonial use rather than transportation. It may have been able to roll forward and produce a planned movement, making it useful as a stage effect. Leonardo’s drawings show the mechanism, but they do not establish that he built a full working version.

This cart is sometimes called a robot in popular accounts, although it was not humanoid. It should also be distinguished from Leonardo’s later mechanical lion and mechanical knight, which used different forms and purposes.