US5359836A — Agricultural harvester with closed loop header co…

Claim 1

Independent Claim 247 words

A control system for an agricultural harvester having a cut crop receiving header coupled to a hydraulic cylinder, the header applying a force against the ground which is adjusted by applying fluid under pressure to the cylinder, comprising: first proportional control valve means fluidly coupled to the cylinder responsive to a first input signal for increasing fluid pressure in the cylinder to a setpoint value, when the pressure in the cylinder is less than the setpoint value; second proportional control valve means fluidly coupled to the cylinder responsive to a second input signal for reducing fluid pressure in the cylinder to the setpoint pressure value when the pressure in the cylinder is greater than the setpoint value; means for producing an electrical pressure signal that represents fluid pressure in the cylinder; and means for determining the first and second input signals as a function of the difference between the pressure signal and the setpoint value, for maintaining pressure in the cylinder substantially at the setpoint value, thereby maintaining the force applied against the ground by the header substantially constant, the determining means comprising: (a) means for generating respective first, second and third signal components that are proportional to the difference between the pressure signal and the setpoint value, the integral of the difference with respect to time and the derivative of the difference with respect to time, and (b) means for combining the first, second and third signal components to form the first and second input signals.

Claim 2

Dependent Claim 247 words

A control system for an agricultural harvester having a cut crop receiving header coupled to a hydraulic cylinder, the header applying a force against the ground which is adjusted by applying fluid under pressure to the cylinder, comprising: first proportional control valve means fluidly coupled to the cylinder responsive to a first input signal for increasing fluid pressure in the cylinder to a setpoint value, when the pressure in the cylinder is less than the setpoint value; second proportional control valve means fluidly coupled to the cylinder responsive to a second input signal for reducing fluid pressure in the cylinder to the setpoint pressure value when the pressure in the cylinder is greater than the setpoint value; means for producing an electrical pressure signal that represents fluid pressure in the cylinder; and means for determining the first and second input signals as a function of the difference between the pressure signal and the setpoint value, for maintaining pressure in the cylinder substantially at the setpoint value, thereby maintaining the force applied against the ground by the header substantially constant, the determining means comprising: (a) means for generating respective first, second and third signal components that are proportional to the difference between the pressure signal and the setpoint value, the integral of the difference with respect to time and the derivative of the difference with respect to time, and (b) means for combining the first, second and third signal components to form the first and second input signals.

Claim 3

Dependent Claim 49 words

A control system in accordance with claim 1, wherein the harvester has a frame, further comprising: pivot means for allowing the header to pivot freely to an angle that is substantially equal to an average angle of the ground beneath the header relative to the frame of the harvester.

Claim 4

Dependent Claim 79 words

A control system in accordance with claim 1, wherein the determining means include: gain means responsive to the signal component generating means for applying respective first, second and third gains to modify the respective first, second and third signal components, and for providing the modified first, second and third signal components to the combining means; and means coupled to the gain means for varying the first, second and third gains when a driving condition of the agricultural harvester changes.

Claim 5

Dependent Claim 30 words

A control system in accordance with claim 3, wherein the gain means include means for varying the first, second and third gains when the speed of the agricultural harvester changes

Claim 6

Dependent Claim 94 words

A control system in accordance with claim 1, further comprising: means for interrupting transmission of the first and second input signals to the first and second control valve means, respectively; means for transmitting a raise signal to cause the first valve means to apply sufficient fluid to the cylinder to raise the header to a predetermined position; means for transmitting a lower signal to cause the second valve means to release sufficient fluid from the cylinder to lower the header to the ground; means for resuming transmission of the first and second input signals.

Claim 7

Dependent Claim 240 words

A control system for an agricultural harvester having a frame and a cut crop receiving header, the header having a position which is adjusted by applying fluid under pressure to a hydraulic cylinder, comprising: first proportional control valve means fluidly coupled to the cylinder responsive to a first input signal for applying fluid to the cylinder when the header is below a setpoint position, until the header reaches the setpoint position; second proportional control valve means fluidly coupled to the cylinder responsive to a second input signal for receiving fluid from the cylinder when the header is above the setpoint position, until the header reaches the setpoint position; means for producing an electrical position signal that represents the position of the header; means for determining the first and second input signals as a function of the difference between the value of the position signal and the value of the setpoint position, for maintaining the position of the header substantially at the setpoint value, thereby maintaining the position of the header substantially constant, the determining means comprising: (a) means for generating respective first, second and third signal components that are proportional to the difference between the position signal and the setpoint value, the integral of the difference with respect to time and the derivative of the difference with respect to time, and (b) means for combining the first, second and third signal components to form the first and second input signals.

Claim 8

Dependent Claim 240 words

A control system for an agricultural harvester having a frame and a cut crop receiving header, the header having a position which is adjusted by applying fluid under pressure to a hydraulic cylinder, comprising: first proportional control valve means fluidly coupled to the cylinder responsive to a first input signal for applying fluid to the cylinder when the header is below a setpoint position, until the header reaches the setpoint position; second proportional control valve means fluidly coupled to the cylinder responsive to a second input signal for receiving fluid from the cylinder when the header is above the setpoint position, until the header reaches the setpoint position; means for producing an electrical position signal that represents the position of the header; means for determining the first and second input signals as a function of the difference between the value of the position signal and the value of the setpoint position, for maintaining the position of the header substantially at the setpoint value, thereby maintaining the position of the header substantially constant, the determining means comprising: (a) means for generating respective first, second and third signal components that are proportional to the difference between the position signal and the setpoint value, the integral of the difference with respect to time and the derivative of the difference with respect to time, and (b) means for combining the first, second and third signal components to form the first and second input signals.

Claim 9

Dependent Claim 79 words

A control system in accordance with claim 6, wherein the determining means include: gain means responsive to the signal component generating means for applying respective first, second and third gains to modify the respective first, second and third signal components, and for providing the modified first, second and third signal components to the combining means; and means coupled to the gain means for varying the first, second and third gains when a driving condition of the agricultural harvester changes.

Claim 10

Dependent Claim 101 words

A control system in accordance with claim 6, further comprising: means for interrupting transmission of the first and second input signals to the first and second valve means, respectively; raising means for generating and transmitting a raise signal to cause the first valve means to apply sufficient fluid to the cylinder to raise the header to a raised position; lowering means for generating and transmitting a lower signal to cause the second valve means to release sufficient fluid from the cylinder to lower the header to a predetermined transition position; means for resuming transmission of the first and second input signals.

Claim 11

Dependent Claim 58 words

A control system in accordance with claim 8, wherein the lowering means include: means for storing velocity profile data including respective velocity and time coordinates; and means for adjusting the lower signal, so that the header is lowered at a velocity substantially equal to each respective velocity coordinate at respective times that are related to the time coordinates.

Claim 12

Dependent Claim 34 words

A control system in accordance with claim 8, further comprising a plurality of ground sensors having a maximum working height, wherein the predetermined transition position is the maximum working height of the ground sensors.

Claim 13

Dependent Claim 237 words

A control system for an agricultural harvester having a frame, a feeder house pivotally mounted on the frame and a cut crop receiving header, the header having a position which is adjusted by applying fluid under pressure to a hydraulic cylinder, comprising: first proportional control valve means fluidly coupled to the cylinder responsive to a first input signal for applying fluid to the cylinder when the header is below a setpoint position, until the header reaches the setpoint position; second proportional control valve means fluidly coupled to the cylinder responsive to a second input signal for receiving fluid from the cylinder when the header is above the setpoint position, until the header reaches the setpoint position; means for producing an electrical position signal that represents the position of the header; means for determining the first and second input signals as a function of the difference between the value of the position signal and the value of the setpoint position, for maintaining the position of the header substantially at the setpoint value, thereby maintaining the position of the header substantially constant; a plurality of ground sensors attached to the header, for measuring the position of the header, the ground sensors having a maximum working height; and means for measuring an angle between the feeder house and the frame and for computing the position of the header from the angle when the header is above the maximum working height.

Claim 14

Dependent Claim 237 words

A control system for an agricultural harvester having a frame, a feeder house pivotally mounted on the frame and a cut crop receiving header, the header having a position which is adjusted by applying fluid under pressure to a hydraulic cylinder, comprising: first proportional control valve means fluidly coupled to the cylinder responsive to a first input signal for applying fluid to the cylinder when the header is below a setpoint position, until the header reaches the setpoint position; second proportional control valve means fluidly coupled to the cylinder responsive to a second input signal for receiving fluid from the cylinder when the header is above the setpoint position, until the header reaches the setpoint position; means for producing an electrical position signal that represents the position of the header; means for determining the first and second input signals as a function of the difference between the value of the position signal and the value of the setpoint position, for maintaining the position of the header substantially at the setpoint value, thereby maintaining the position of the header substantially constant; a plurality of ground sensors attached to the header, for measuring the position of the header, the ground sensors having a maximum working height; and means for measuring an angle between the feeder house and the frame and for computing the position of the header from the angle when the header is above the maximum working height.

Claim 15

Dependent Claim 209 words

A control system for an agricultural harvester having a frame and a feeder house pivotally mounted oil the frame and a cut crop receiving header coupled to the feeder house, the header having a plurality of ground sensors, comprising: means for measuring an angle between the feeder house and the frame and for computing the position of the header from the angle; means for monitoring a plurality of feedback signals from the ground sensors while lowering the header from a raised position to the ground; means for identifying the highest position at which the respective feedback signal from each respective ground sensor changes in response to further lowering of the header as the maximum working height of that ground sensor; means for identifying the highest position below the maximum working height at which the respective feedback signal from each respective ground sensor does not change in response to further lowering of the header as the minimum working height of that ground sensor; means for correlating the respective values of the feedback signal from each sensor at its respective maximum and minimum working heights with respective measurements of the positions determined by the angle measuring means at the maximum and minimum working heights, thereby calibrating each of the ground sensors.

Claim 16

Dependent Claim 209 words

A control system for an agricultural harvester having a frame and a feeder house pivotally mounted oil the frame and a cut crop receiving header coupled to the feeder house, the header having a plurality of ground sensors, comprising: means for measuring an angle between the feeder house and the frame and for computing the position of the header from the angle; means for monitoring a plurality of feedback signals from the ground sensors while lowering the header from a raised position to the ground; means for identifying the highest position at which the respective feedback signal from each respective ground sensor changes in response to further lowering of the header as the maximum working height of that ground sensor; means for identifying the highest position below the maximum working height at which the respective feedback signal from each respective ground sensor does not change in response to further lowering of the header as the minimum working height of that ground sensor; means for correlating the respective values of the feedback signal from each sensor at its respective maximum and minimum working heights with respective measurements of the positions determined by the angle measuring means at the maximum and minimum working heights, thereby calibrating each of the ground sensors.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1997-10-31	1998-05-02	1998-11-01	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2001-10-31	2002-05-02	2002-11-01	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2005-10-31	2006-05-02	2006-11-01	$7700.00	Window Closed / Lapsed

Agricultural harvester with closed loop header control

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