A system for controlling the loading of grain in a grain bag is described. The system includes a grain cart, a tractor attached to the grain cart, and a grain bagger with an attached grain bag. The grain bagger further comprises a steering and steering control systems and a braking and braking control system. A hopper connected to the grain bagger receives grain from an auger connected with the hopper and auger and defines a loading position in which a distal end of the auger is positioned relative to the hopper such that grain transfers from the auger into the hopper. A controller provides velocity and steering commands to the tractor and a coordinated movement system connected to the controller receives position information as to the auger and hopper and provides course adjusting information so as to maintain the auger and hopper in the loading position.
