System and method for controlling a hydrostatic drive unit of a work vehicle

A system for controlling a hydrostatic drive unit of a work vehicle, the system comprising:

• a hydraulic pump including a swashplate;
• a sensor associated with the hydraulic pump, the sensor being configured to monitor an actual swashplate position of the swashplate;
• a valve configured to regulate a pressure of a hydraulic fluid supplied to the hydraulic pump, the pressure of the hydraulic fluid being related to the actual swashplate position;
• and
• a controller communicatively coupled to the sensor and the valve, the controller being configured to both determine a reference swashplate position for the swashplate based on operator inputs and determine a valve current adjustment based at least in part on the actual and reference swashplate positions, the controller being further configured to generate an adjusted valve current command for the valve based on the current compensation, the adjusted valve current command being associated with moving the swashplate to an adjusted swashplate position that is defined between the reference swashplate position and the actual swashplate position, the controller being configured to control the valve based on the adjusted current command such that the swashplate is moved to the adjusted swashplate position,
• wherein, at the adjusted swashplate position, the hydrostatic drive unit drives the work vehicle at a vehicle speed that is less than a vehicle speed associated with the reference swashplate position.

A method for controlling a hydrostatic drive unit of a work vehicle, the method comprising:

• determining a reference swashplate position for a swashplate of a hydraulic pump of the hydrostatic drive unit, the reference swashplate position being associated with an unadjusted valve current command;
• monitoring an actual swashplate position of the swashplate, the actual swashplate position differing from the reference swashplate position due to a loading condition of the work vehicle;
• determining a proportional gain based on the difference between the actual swashplate position and the reference swashplate position;
• generating an adjusted valve current command by modifying the unadjusted valve current command based on the proportional gain, the adjusted valve current command being associated with moving the swashplate to an adjusted swashplate position that differs from the reference swashplate position;
• and
• controlling a valve of the work vehicle based on the adjusted valve current command such that the swashplate is moved to the adjusted swashplate position,
• wherein the proportional gain is calculated according to the following equation:
• k
• =
• 1
• -
• B
• r
• B
• p
• G
• wherein, k corresponds to the proportional gain, Br corresponds to a desired load sensitivity for the hydraulic pump, Bp corresponds to an actual load sensitivity for the hydraulic pump and G corresponds to a steady state control gain for the hydraulic pump.