What vehicle did Leonardo da Vinci design to move by itself using wound springs?

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

The cart appears in drawings from around 1478 to 1480 and is often described as an early automobile or robotic vehicle. Two symmetrical leaf springs stored energy, while a system of gears transferred that energy to the wheels. A steering mechanism could be set in advance, allowing the cart to follow a predetermined path.

Because it moved without someone pushing or pulling it, the device is also considered an early programmable automaton. It may have been intended for theatrical performances or court events rather than transportation. The cart had no engine, passenger compartment, or means of continuous powered travel.

A working reconstruction was made in 2006 by Italian researchers and was displayed at the Clos Lucé in France. The reconstruction showed that the mechanism could operate, although interpretations of the original drawings differ in some details.