What Renaissance vehicle did Leonardo da Vinci design to move automatically using coiled springs?

Leonardo da Vinci designed a self-propelled cart to move automatically using coiled springs.

The cart, usually dated to around 1478–1480, used two large springs concealed beneath its body. When wound, the springs supplied mechanical power to the wheels. Cams and other components controlled the cart’s movement, allowing it to travel along a predetermined path rather than being pushed by a person or pulled by an animal.

The design is often described as an early robot or programmable machine, although Leonardo did not call it either term. It may have been intended for theatrical performances or court ceremonies, where a moving object could create a dramatic effect.

A full-scale reconstruction was built in the early 21st century from Leonardo’s drawings. The vehicle is not the same as his armored military wagon: the self-propelled cart was a transport and spectacle machine powered by springs, while the armored vehicle was designed for warfare.