What self-moving machine did Leonardo da Vinci design that is often called the first robotic vehicle?

Leonardo da Vinci designed a self-propelled cart that is often described as an early programmable machine or the first robotic vehicle.

The cart appears in drawings from around 1478–1480. Coiled springs supplied its motive power, while a system of gears and cams controlled movement. By setting the cams, a builder could determine how far the cart traveled and how it turned.

The machine was probably intended for theatrical or ceremonial use rather than transportation. It may have been able to move across a stage and perform a predetermined action without a person visibly pushing it.

Leonardo's drawings were incomplete, so modern reconstructions have been important in understanding the mechanism. In 2006, a replica was built and tested in Florence. Calling it a robot is useful as a modern comparison, but it did not sense its surroundings or make decisions like a contemporary autonomous robot.