Construction machine control method and construction machine control system

A construction machine control system, comprising

• a laser surveying instrument for projecting N-shaped beams in rotary irradiation at constant speed,
• a construction machine operated within a predetermined range of said N-shaped beams, and
• an elevation angle detecting unit,
• wherein said construction machine comprises a working mechanical unit for carrying out construction operation, a machine control device for controlling said working mechanical unit, and at least three beam detectors disposed at known positions respectively with respect to reference position of said construction machine,
• wherein said laser surveying instrument comprises an N-shaped beam projecting unit for projecting said N-shaped beams having three fan beams in rotary irradiation and a surveying control device,
• wherein said beam detectors detect said three fan beams and outputs result of photodetection,
• wherein said elevation angle detecting unit is provided on either one of said beam detectors, said machine control device or said laser surveying instrument, and obtains elevation angles of each of said beam detectors with respect to said laser surveying instrument based on result of photodetection of three fan beams from said beam detectors,
• and wherein said machine control device is configured so as to control tilting of said working mechanical unit based on the elevation angle obtained.