Patent ID: 7632179

Claim:
A method to sense incipient slugging in a combine having a rotor for threshing crop material, an internal combustion engine configured to be coupled to the rotor to drive the rotor; and a hydraulic motor configured to be coupled to the rotor to drive the rotor, the method comprising the steps of: sensing a first motor speed with a motor speed sensor; sensing an engine speed with an engine speed sensor; sensing a rotor speed with a rotor speed sensor; a controller combining the engine speed and the rotor speed to provide a second motor speed; the controller determining incipient slugging based upon the first motor speed and the second motor speed; wherein if slugging is determined, disengaging the rotor from both the engine and the motor; wherein if slugging is not determined, determining rates of change of a signal from the motor speed sensor, a signal from the engine speed sensor and a signal from the rotor speed sensor; and determining incipient slugging based upon the three rates of change.