Hydraulic control circuit and method thereof

A hydraulic control circuit for driving an actuator by controlling a pressurized fluid from a hydraulic pump, the hydraulic control circuit comprising:

• a control lever for generating a manipulated signal according to a manipulated variable;
• a control valve installed on a supply line connecting the hydraulic pump and the actuator and driven by a pilot signal pressure for controlling a flow of the pressurized fluid traveling from the hydraulic pump to the actuator;
• a displacement sensor installed on an end of the control valve for detecting a switching position of the control valve;
• a pump pressure sensor installed on the supply line for detecting a pump pressure applied to the hydraulic pump;
• at least one electronic proportional valve driven by an external control signal for supplying a pilot signal pressure to the control valve;
• and
• a controller for receiving the manipulated signal from the control lever to determine a pilot signal pressure to be supplied to the control valve, outputting a corresponding control signal to the electronic proportional valve(s), receiving signals from the displacement sensor and the pump pressure sensor and comparing the signals with pre-stored reference data, and outputting to the electronic proportional valve(s) a stroke error correcting control signal for adjusting the switching position of the control valve
• wherein if an error is found in both switching position of the control valve and the pump pressure compared with the reference data of a present pilot signal pressure, the controller outputs to the electronic proportional valve(s) the stroke error correcting control signal for adjusting the switching position of the control valve.