What self-propelled machine did Leonardo da Vinci design that is often described as an early robot or car?

Leonardo da Vinci designed a self-propelled cart that is often described as an early robot or car.

The machine, drawn around 1478 to 1480, used coiled springs to store energy. The springs drove the wheels through a system of gears, allowing the cart to move without being pushed continuously by a person or animal. A steering mechanism could be set in advance through adjustable components.

Leonardo may have intended the cart for theatrical performances or court celebrations rather than transportation. Its movement would have been limited and preprogrammed, so it was not an automobile in the modern sense.

The design was reconstructed in the early 21st century by researchers and museum specialists. Those reconstructions demonstrated that the basic mechanism could work, while also showing why the cart should be understood as a programmable mechanical device rather than a powered road vehicle.