METHOD FOR CONTROLLING HYDRAULIC SYSTEM OF CONSTRUCTION MACHINERY

摘要

The present disclosure relates to a method for controlling a hydraulic system of construction machinery. The method for controlling the hydraulic system of construction machinery according to the present disclosure includes an engine speed prediction step, in which a variable rated engine speed, which varies within a range larger than a fixed rated engine speed and smaller than a high idle engine speed for the fixed rated engine speed and a virtual engine speed, which is to be input later, are predicted to output a virtual engine speed value predicted before an actual engine speed is input. Accordingly, when an operation load is applied, pump torque may initially have a margin, and even though an engine speed is decreased due to the operation load, it is possible to prevent an engine speed decrease phenomenon in which the engine speed becomes remarkably smaller than the rated engine speed.

主权项

1. A method for controlling a hydraulic system of construction machinery, the method comprising:
a maximum value setting step, in which when a required torque value for a pump is generated, the required torque value is set to a maximum value; a power conversion step, in which a power value matched to a current load mode and the maximum value is output; an inclination limit step, in which a conversion speed of the power value per hour is limited; an engine speed prediction step, in which a virtual engine speed to be input later is predicted before an actual engine speed is input by receiving the actual engine speed from an engine control device; a PID control step, in which proportional integral derivative control is performed so that the actual engine speed converges the virtual engine speed; and a final power output step, in which the pump is controlled with a final power value obtained by adding a first power value determined by the load mode, a second power value determined by the required torque value for the pump, and a third power value deduced by the PID control.