What Renaissance machine did Leonardo da Vinci design to move without being pushed by a person or animal?

Leonardo da Vinci designed a self-propelled cart that could move without being pushed by a person or animal.

The machine, described in Leonardo's Codex Atlanticus and usually dated to the late fifteenth century, used coiled springs to store energy. When released, the springs turned the cart's wheels through a system of gears and cables. A steering mechanism could be set in advance, allowing the cart to follow a predetermined route.

Because its movement was controlled rather than continuously powered by a driver, the cart is often called an early robot or a precursor of the automobile. It was not an automobile in the modern sense: it had no engine, fuel tank, brakes, or steering wheel for a driver.

The reconstruction of Leonardo's cart has shown that the basic mechanism can work, although scholars debate its intended purpose. It may have been designed for theatrical performances, court spectacles, or engineering demonstrations. Leonardo's plans were incomplete, so modern reconstructions necessarily interpret some details.