An autonomous self-propelled grain cart for short-coupled operation with a grain harvesting combine includes a frame and an operator's cab affixed to the frame. The operator's cab includes interactive controls for steering, regulating propulsion, and utility operation by an operator. A plurality of drive units propel the cart over the surface of an agricultural field. A grain hopper includes a grain bin and an unloading apparatus. A power system is electrically communicative with the drive units and the grain hopper unloading apparatus. The grain cart also includes a position sensing system, and a control system. The control system includes a central processing unit having an associated memory, a display, a user input device, and an instruction set resident in the memory. The instruction set, when executed and integrated with the position sensing system, functions to autonomously maintain a close-coupled position with respect to an operating combine.
