Leonardo da Vinci’s self-propelled cart was a spring-powered vehicle designed to move without a driver.
Leonardo drew the machine around 1478–1480. Its movement came from coiled leaf springs, while a system of cams controlled the distance and direction it traveled. The design could therefore perform a prearranged movement rather than simply roll freely.
The cart is often described as an early ancestor of the automobile, although it was not an engine-powered car. It had no internal-combustion engine and was intended more as a theatrical or ceremonial device than as practical transport. A modern reconstruction demonstrated that the mechanism could work.
The cart is sometimes called a robot or automobile, but “self-propelled cart” is the clearest name. Leonardo’s related studies of gears, springs, and cams show how closely his mechanical designs connected engineering with stage entertainment.