Patent ID: 8346450

Claim:
A method for controlling slip of a tractor vehicle in which drive wheel slip is determined, the drive wheel slip being determined by simultaneous measuring a drive wheel rotational speed and an actual driving speed of the vehicle over ground and comparing the measured values and, if the actual slip is different from a specified nominal slip, a gear ratio of a controllable transmission in the drivetrain is adjusted in a direction of slip optimization, and the optimization objective being selected by a driver of the vehicle, the method comprising the steps of: regulating the gear ratio such that the drive wheel rotation speed is controlled by adjusting the gear ratio by a geared-neutral process in which a transmission input power branches into first and second power branches, via a branching transmission, and the first and the second power branches are brought together again by a summation gearing such that a speed of the first power branch is varied continuously; and changing a sum of the speeds of the first and the second power branches, which essentially equals an output speed on which the speed of the drive wheel depends; and selecting the optimization objective from either a slip optimization in a sense of maximum traction force, a slip optimization in a sense of a specified ground protection, or adjustment of the slip to values in a range between a point of maximum traction force and a point of maximum ground protection.