Electronic combine head float control system

In an agricultural vehicle including a moveable implement for operation on a surface and including a positioner for moving the implement in response to pulse-width modulated signals at velocities dependent on the duration of pulses of the signals, an electronic implement float control system comprising:

• transducer means for producing a force signal representative of the support force at which the surface supports the implement;
• conversion means for producing digital force data representative of the force signal;
• and
• digital processing means for storing digital setpoint data representative of a desired support force, comparing the digital force data to the digital setpoint data, applying first pulse-width modulated signals having pulse durations dependent on the comparison to the positioner such that the implement is raised from the surface at velocities dependent on the comparison when the support force is greater than the desired support force, and applying second pulse-width modulated signals having pulse durations dependent on the comparison to the positioner such that the implement is lowered toward the surface at velocities dependent on the comparison when the support force is less than the desired support force.

A combine comprising:

• a support structure for supporting the components of the combine;
• at least four wheels for movably supporting the combine on a surface and mechanically coupled to the support structure, at least one of the wheels being powered to move the combine in a first direction;
• an implement configured to harvest plant related matter when the combine moves in the first direction, the implement being movably supported by the support structure at the front-most end of the combine relative to the first direction;
• an implement positioner coupled to the support structure to move the implement relative to the combine in response to electronic control signals;
• a force transducer coupled to the implement to produce a force signal representative of the support force at which the surface supports the implement;
• a conversion circuit coupled to the force transducer to produce digital force data representative of the force signal;
• and
• a digital processing circuit coupled to the conversion circuit to store digital setpoint data representative of a desired support force, compare the digital force data to the digital setpoint data, apply first pulse-width modulated control signals to the positioner, the control signals having pulse durations dependent on the comparison, such that the implement is raised from the surface at a velocity dependent on the comparison when the support force is greater than the desired support force, and apply second pulse-width modulated control signals to the positioner, the control signals having pulse durations dependent on the comparison, such that the implement is lowered toward the surface at velocities dependent on the comparison when the support force is less than the desired support force.