What self-moving machine did Leonardo da Vinci design around 1478, often considered an early robot?

Leonardo da Vinci designed a self-propelled cart around 1478, a machine often described as an early robot or programmable automaton.

The cart was powered by coiled springs hidden inside its body. When released, the springs turned the wheels, allowing the machine to move without being pushed. A system of cams controlled its steering, so the path could be set in advance rather than guided continuously by a driver.

The surviving drawings do not provide every construction detail, and scholars have debated how the original mechanism worked. Modern reconstructions have shown that the concept is mechanically plausible. In 2006, researchers and engineers associated with the Institute and Museum of the History of Science in Florence built a working reconstruction based on Leonardo's sketches.

The cart is not a robot in the modern electronic sense. It had no sensors, software, or feedback system. Its significance lies in programmable mechanical motion: cams and springs could produce a predetermined sequence of actions. It may have been intended for theatrical or ceremonial use, perhaps to move across a stage or into a court presentation.