What self-moving invention did Leonardo da Vinci design in the form of a spring-powered cart?

Leonardo da Vinci’s spring-powered cart was a self-propelled cart.

Leonardo designed the machine in the late 15th century as a vehicle that could move without being pushed by a person or pulled by an animal. Large coiled springs stored energy, while a system of gears transferred that energy to the wheels. Steering could be set in advance, allowing the cart to follow a programmed route.

The cart is sometimes called a robot because it could perform a movement sequence automatically. It was not an automobile: it had no internal-combustion engine, electric motor, brakes, or driver’s controls. Its likely uses included theatrical performances and court spectacles.

Modern reconstructions have helped researchers understand the mechanism. In 2006, a replica was built and tested in Italy. The design is important in the history of automata because it shows Leonardo applying clockwork ideas to a larger moving machine.