Continuously adjustable control management for a hydraulic track system

A method for varying the start of control pressure of a variable displacement hydraulic motor adapted to drive a track system of a machine along a ground surface, the machine including user controls for controlling the functionality of the machine, a controller in electrical communication with the user controls, a control valve biased in a first position by a spring having a fixed spring force, and a proportional electro-hydraulic valve electrically coupled to the controller and fluidly coupled to the control valve, the method comprising:

• sending an electrical signal to the proportional electro-hydraulic valve;
• moving the proportional electro-hydraulic valve from a substantially closed position to any one of a plurality of open positions;
• fluidly coupling the proportional electro-hydraulic valve and control valve to one another;
• controllably moving the control valve from the first position to any one of a plurality of control positions;
• and
• varying the start of control pressure of the motor with the proportional electro-hydraulic valve between a first start of control pressure and a second start of control pressure, the first and second start of control pressures triggered at approximately the same motor displacement and machine travel speed but at different surface grades, where the first start of control pressure is triggered at a smaller surface grade than the second start of control pressure.

A method of controlling a variable displacement hydraulic motor for driving a machine, the machine including operator controls for controlling the operation of the machine, a controller in electrical communication with the operator controls, a control valve biased in a first position and disposed in fluid communication with the motor, a pump, and a proportional electro-hydraulic valve electrically coupled to the controller and fluidly coupled to the control valve, the method comprising:

• receiving an input signal from the operator controls, where the input signal corresponds to a desired machine operation;
• sending an electrical signal to the proportional electro-hydraulic valve based on the input signal;
• moving the proportional electro-hydraulic valve between a substantially closed position and any one of a plurality of open positions;
• fluidly coupling the pump, the proportional electro-hydraulic valve and the control valve to one another when the proportional electro-hydraulic valve is disposed in any one of its plurality of open positions;
• controllably moving the control valve from the first position to a second position based on the electrical signal;
• controlling the motor within a start of control pressure region based on the desired machine operation, wherein the start of control pressure region is defined by a first profile curve, a second profile curve, a minimum motor displacement, and a maximum motor displacement, the first profile curve including a first start of control pressure point and a first maximum displacement point, and the second profile curve including a second start of control pressure point and a second maximum displacement point;
• and
• operating the machine at a first speed corresponding to the first and second start of control pressure points at the minimum motor displacement, and at a second speed corresponding to the first and second maximum displacement points at the motor maximum displacement, where the first speed is greater than the second speed.