What self-moving vehicle did Leonardo da Vinci design using springs to power its wheels?

Leonardo da Vinci designed a self-propelled cart powered by coiled springs and concealed mechanical gearing.

The cart appears in drawings from the late 15th century and is often described as an early programmable or autonomous machine. Its springs could store energy, while a system of gears and cams controlled the movement of the wheels. Adjustable pegs allowed the path to be set before the cart moved.

The machine was probably intended for theatrical or ceremonial use rather than transportation. A modern reconstruction built in 2006 showed that the basic mechanism could work, although reconstructions necessarily interpret incomplete historical evidence.

The cart is sometimes called Leonardo’s robot, but that label can mislead. It did not think or respond to its environment. In modern terms, it was a mechanical automaton: a machine whose actions were determined by its preset mechanism.