Leonardo da Vinci sketched a self-propelled cart that is often described as an early robot or automobile.
The cart, usually dated to around 1478–1480, used coiled springs to store energy. When released, the springs drove the wheels through a system of gears. Steering could be set in advance, allowing the vehicle to follow a programmed route rather than being continuously directed by a driver.
It was probably intended for theatrical or ceremonial use, such as carrying scenery or appearing to move by itself at a court event. That makes it an automaton more than an automobile in the modern transport sense. Leonardo’s drawing does not provide a complete modern-style set of manufacturing instructions, so reconstructions have been important for testing how the mechanism may have worked.
The cart is also connected with the later design of a mechanical lion that could move during performances, although the two machines were separate projects.