Laser beam guidance device for civil engineering/earthmoving plant

A device for guiding an earthmoving machine which is controlled with at least one actuator such that said earthmoving machine moves along a predetermined path having a three dimensional surface, said device comprising:

• first and second laser emitters for generating first and second laser beams;
• at least four displacement means mounted on said earthmoving machine, each of said at least four displacement means having a corresponding two degrees of freedom;
• a laser receiver mounted to each one of said at least four displacement means so as to receive one of said first and second laser beams, two of said laser receivers receiving said first laser beam, two of said laser receivers receiving said second laser beam;
• means in communication with said at least four displacement means for sensing the position of each of said at least four displacement means with respect to said corresponding two degrees of freedom, said sensing means generating output signals corresponding to the position of each of said at least four displacement means;
• second means mounted to said earthmoving machine for sensing the position of said earthmoving machine with respect to said predetermined path, said second sensing means generating a second output signal corresponding to the position of said earthmoving machine with respect to said predetermined path;
• and
• computer means in communication with said at least one actuator, said sensing means, said second sensing means, and said laser receivers for storing data corresponding to said three dimensional surface of said predetermined path, for controlling said at least four displacement means so as to position said laser receivers to receive said first and second laser beams generated by said first and second laser emitters, and for controlling said at least one actuator so as to substantially maintain said earthmoving machine on said predetermined path.