What type of vehicle did Leonardo da Vinci design with four wheels and a rotating drum for movement?

Leonardo da Vinci designed a self-propelled cart with four wheels and a rotating drum mechanism.

The cart’s driving energy came from coiled springs housed inside the mechanism. As the springs unwound, gears transferred torque to the wheels. A rotating drum helped control the timing and direction of the motion, while a preset steering arrangement could guide the vehicle along a chosen path.

The design dates to the late fifteenth century and is often presented as an ancestor of the automobile. That comparison is useful only in a broad historical sense: the cart had no internal-combustion engine, fuel tank, or modern steering system.

It is also frequently called a robot because it could perform a programmed movement. In modern terms, however, it was an automaton or mechanical vehicle, not an autonomous robot capable of sensing its environment.