What self-moving device did Leonardo da Vinci design around 1478 that is often called the first robot?

Leonardo da Vinci designed a self-propelled cart around 1478 that is often called the first robot.

The cart was a spring-powered mechanical device capable of moving without being pushed or pulled by a person. Its internal system used coiled springs, gears, and a programmable control arrangement involving pegs. The mechanism could set the cart on a predetermined path rather than giving it independent intelligence.

Leonardo’s drawing does not survive as a complete, fully explained construction plan, so modern reconstructions rely on careful study of his notebooks. In 2006, an Italian team built a working reconstruction that demonstrated the basic movement of the design.

The word “robot” can be misleading because modern robots usually sense their environment or execute electronic programs. Leonardo’s cart was an automaton: a machine that performed preset actions through mechanical control. It is still important because it shows his interest in automation, springs, gearing, and programmable movement.