The present invention provides a solution that enables a single rotary laser
apparatus to control more than one construction machines so that the construction
machines can simultaneously level the terrain up or down to different elevations,
respectively. A construction machine control system (100) according to the
present invention comprises a rotary laser apparatus (151) that emits at
least two fan-shaped laser beams diverted in a plane other than horizontal plane
while rotating the laser beams about a given axis, an optical sensor (154)
mounted on a construction machine (502) to receive the fan-shaped laser
beams, a GPS receiver mounted on the construction machine to determine a position
of the construction machine, and an arithmetic operation device mounted on the
construction machine, where one of the fan-shaped laser beams is emitted at different
elevation or depression angle from that of the other, and the arithmetic operation
device receives a detected signal from the GPS receiver to determine the position
of the construction machine and also receives a delay between times when the optical
sensor receives the fan-shaped laser beams, respectively, to compute and produce
a control signal over the construction machine.