Control system for construction machinery and control method for construction machinery using the same

A control system for construction machinery, the control system comprising:

• first and second hydraulic pumps connected to an engine;
• a swing control valve installed in an upstream portion of a first center bypass line connected to the first hydraulic pump, the swing control valve configured to control a drive of a swing motor;
• a first boom control valve installed downstream in the first center bypass line next to the swing control valve, the first boom control valve configured to control a drive of a boom cylinder;
• a second boom control valve installed in a second center bypass line connected to the second hydraulic pump, the second boom control valve configured to control the drive of the boom cylinder;
• a shutoff valve installed in a control line through which a boom raising pilot signal pressure for raising a boom of the boom cylinder is supplied to the first boom control valve and configured to selectively open and close the control line;
• and
• a control unit including a first pressure sensor for detecting a boom raising pilot signal pressure supplied to the second boom control valve, a second pressure sensor for detecting a swing pilot signal pressure supplied to the swing control valve, a selection switch for selecting a swing operation priority mode, and a controller configured to receive pressure information and a selection signal from the first and second pressure sensors and the selection switch and electronically control the shutoff valve, wherein the controller closes the shutoff valve such that the first boom control valve is shifted to a neutral position when the swing operation priority mode is selected,
• wherein the swing control valve and the first boom control valve are connected parallel with each other to the first hydraulic pump by a parallel line.

A method for controlling construction machinery, the method comprising:

• obtaining manipulation information and swing operation priority mode selection information in construction machinery;
• supplying a hydraulic fluid to a boom cylinder head when receiving a boom raising manipulation signal in case a swing operation priority mode is not selected;
• and
• shutting off the hydraulic fluid to the boom cylinder head when receiving the boom raising operation manipulation signal and a swing operation manipulation signal in case the swing operation priority mode is selected.