Agricultural harvester ground tracking control system and method using fuzzy logic

A control system for an agricultural harvester having a frame, a feeder house coupled to a hydraulic cylinder, and a cut crop receiving header, the header having a height relative to the frame that is adjusted by applying fluid under pressure to the cylinder, comprising:

• first control valve means fluidly coupled to the cylinder responsive to a first input signal for supplying fluid to the cylinder to raise the header;
• second control valve means fluidly coupled to the cylinder responsive to a second input signal for removing fluid from the cylinder to lower the header;
• means for receiving and storing an input value that is used to control the rate of change of header acceleration while raising or lowering the header;
• means for producing an electrical feeder house angle signal that varies as a function of an angle between the feeder house and the frame;
• fuzzy inferring means for determining the first and second input signals by fuzzy inference based on the input value and the feeder house angle signal.

A control system for an agricultural harvester having a frame and a cut crop receiving header coupled to a hydraulic cylinder, the header having a cutter pivotably mounted on a bottom thereof, the header having a height relative to the frame that is adjusted by applying fluid under pressure to the cylinder, comprising:

• first control valve means fluidly coupled to the cylinder responsive to a first input signal for supplying fluid to the cylinder to raise the header;
• second control valve means fluidly coupled to the cylinder responsive to a second input signal for removing fluid from the cylinder to lower the header;
• means for producing an electrical flex angle signal that represents a flex angle between the bottom of the header and the cutter;
• means for identifying and storing recent values of the flex angle signal which are measured as the cutter passes over the ground;
• means for receiving and storing an operator defined value, and
• means for determining the first and second input signals by fuzzy inference based on the stored values of the flex angle signal and the operator defined value.