What machine did Leonardo da Vinci design to move without a horse, often called his self-propelled cart?

Leonardo da Vinci designed a self-propelled cart that could move without a horse.

The machine appears in drawings from around 1478 to 1480 and is powered by coiled springs hidden inside its body. As the springs unwind, gears transfer their motion to the cart's wheels. A programmable steering mechanism, using pegs on a drum, could make the cart follow a set route and turn.

The vehicle may have been intended for theatrical displays at court rather than for practical transportation. Leonardo's notes do not provide a complete modern construction manual, so later reconstructions have had to interpret missing dimensions and mechanical details. In 2006, an Italian team built and demonstrated a working replica based on the surviving drawings.

It is often called a robot because it could perform a programmed movement, but it was not an autonomous robot in the modern electronic sense. It had no computer, sensors, or artificial intelligence. The cart is better described as an early programmable mechanical automaton and an important example of Leonardo's interest in springs, gears, steering, and stage technology.