What Leonardo da Vinci invention used clockwork to move a small cart without a driver?

Leonardo da Vinci designed a self-propelled cart that used clockwork to move without a driver.

The cart appears in drawings from around 1478 to 1480. Springs stored energy, while a system of gears and components transferred that energy to the wheels. Adjustable cams could determine the route, allowing the cart to move through a programmed sequence rather than being pushed continuously by a person.

It was not an automobile in the modern sense. The machine had no combustion engine, steering wheel, or passenger cabin, and its range would have been limited by the stored spring energy. It is better understood as a mechanical automaton or programmable vehicle.

In 2006, researchers and museum engineers constructed a full-scale replica based on Leonardo's drawings. The reconstruction demonstrated that the basic mechanism could work. The cart is sometimes connected with Leonardo's theatrical devices, because automated motion could have been useful for court spectacles and stage effects.