The wheeled Renaissance vehicle commonly linked to Leonardo da Vinci’s programmed-motion designs is the self-propelled cart.
Leonardo’s drawing shows a three-wheeled vehicle powered by coiled springs rather than by an animal or a person pushing it. A system of gears transferred the springs’ energy to the wheels. The steering arrangement also suggests that the cart could follow a preselected path.
Because the original machine has not survived, historians cannot know every detail of its intended operation. The design is often called a robot or an early automobile, but those labels can be misleading. It was a mechanical cart, not a gasoline-powered car, and its movement was limited by spring power.
A full-scale reconstruction made for a 2006 television documentary demonstrated that the design could move. The cart’s mechanisms also helped inspire later interpretations of Leonardo as an early pioneer of programmable machines.