Patent ID: 8720170

Claim:
An agricultural harvester ( 100 ), comprising: a self-propelled vehicle ( 102 ) having a front; a feederhouse ( 106 ) pivotally mounted on the front of the self-propelled vehicle ( 102 ); pneumatic tires ( 116 ) supporting the vehicle ( 102 ) for movement over the ground; a header ( 104 ) mounted on the front of the self-propelled vehicle ( 102 ); hydraulic cylinders ( 202 ) coupled to and between the self-propelled vehicle ( 102 ) and the feederhouse ( 106 ) to raise and lower the feederhouse ( 106 ) when the hydraulic cylinders ( 202 ) are extended and retracted; a valve ( 214 ) coupled to the hydraulic cylinders ( 202 ) to control hydraulic fluid flow to the hydraulic cylinders ( 202 ) from a source of hydraulic fluid under pressure, and to conduct hydraulic fluid from the hydraulic cylinders ( 202 ) to a reservoir; a header height control circuit ( 208 ) further comprising an electronic control unit ( 210 ) coupled to the valve ( 214 ) wherein the electronic control circuit is configured to drive the valve ( 214 ) to raise and lower the header ( 104 ), a tire compression sensor ( 212 ) coupled to the electronic control circuit ( 210 ) wherein the tire compression sensor is configured to provide the electronic control unit ( 210 ) with a signal indicative of compression of the pneumatic tires ( 116 ), and a header height sensor ( 108 ) disposed to generate a signal indicative of the height of the header ( 104 ) with respect to the ground and wherein the electronic control unit ( 210 ) is configured to receive the signal indicative of compression of the pneumatic tires ( 116 ), and to receive the signal indicative of the height of the header ( 104 ) with respect to the ground, and to combine the two signals to create a compensated header height signal.