Blade control system for bulldozer

Claim 2

In a blade control system for a bulldozer for performing ground leveling work or grading work by automatically controlling a vertical position of a blade of a bulldozer during the work, of the type comprising a light projecting means for forming over a predetermined ground area a horizontal optical reference plane or an oblique optical reference plane inclined at an arbitrary angle, said light projecting means being installed at a location remote from said bulldozer; a light receiving means mounted on a tractor body portion of said bulldozer for detecting said optical reference plane formed by said light projecting means to issue a level signal; and a control means which receives said level signal to control a hydraulic valve actuator of said bulldozer based on said level signal, which hydraulic valve actuator moves said blade of said bulldozer, the improvement wherein: said light receiving means comprises at least a pair of photo receivers which are respectively arranged along a longitudinal axis of said tractor body portion of said bulldozer and spaced apart from each other to form a tractor reference plane therebetween; and a blade controller which controls said hydraulic valve actuator based on a first output signal issued from one of said photo receivers at a first location on said reference plane, and a second output signal issued from the other of said photo receivers at a second location on said reference plane, said second location being longitudinally spaced from said first location, said controller relating said tractor reference plane and said optical reference plane.

Claim 3

The blade control system for the bulldozer as set forth in claim 1, wherein: said light projecting means comprises a pair of photo projectors, each of said photo receivers of said light receiving means has the facility for detecting a three-dimensional position of said tractor body portion of said bulldozer; and said blade controller of said light receiving means controls said hydraulic valve actuator based on an output signal issued from a position measuring controller, which position measuring controller receives said output signal issued from each of said photo receivers to obtain progress data of said work.

Claim 4

The blade control system for the bulldozer as set forth in claim 2, further including a wireless unit and an on-vehicle monitor mounted on said bulldozer in addition to said photo receivers; and a ground wireless unit and a ground monitor installed on the ground.

Claim 5

The blade control system for the bulldozer as set forth in claim 1, wherein: said blade control system further comprises a cylinder stroke sensor which detects a stroke of said hydraulic valve actuator to issue a stroke signal of the thus detected stroke, said stroke signal being fed back to said blade control system.

Claim 6

A blade control system for a bulldozer, comprising: a bulldozer having a tractor body portion defining a longitudinal axis, a blade of said bulldozer for performing ground leveling work or grading work, means for controlling a vertical position of the blade during the work, and means responsive to said controlling means for moving said blade in a vertical direction; light projecting means for forming over a predetermined ground area a horizontal optical reference plane or an oblique optical reference plane inclined at an arbitrary angle, said light projecting means being located at a position remote from said bulldozer and in light communication therewith; a light receiving means mounted on said tractor body portion of said bulldozer for detecting said optical reference plane formed by said light projecting means to issue a level signal to said controlling means, whereby said controlling means controls said vertical position of said blade in response thereto, said light receiving means comprising at least a pair of photo receivers arranged along said longitudinal axis of said tractor body portion of said bulldozer and spaced apart from each other and forming a tractor body reference plane, said controlling means being responsive in part to a distance between the tractor body reference plane and a tractor bearing ground surface to calculate vertical distance to be moved by said blade, said controlling means being responsive in part to a first output signal issued from one of said photo receivers at a first location on said reference plane, and a second output signal issued from the other of said photo receivers at a second location on said reference plane, said second location being longitudinally spaced from said first location, said controller.

Claim 7

A blade control system for a bulldozer, comprising: a bulldozer having a tractor body portion defining a longitudinal axis, a blade of said bulldozer for performing ground leveling work or grading work, means for controlling a vertical position of the blade during the work, and means responsive to said controlling means for moving said blade in a vertical direction; light projecting means for forming over a predetermined ground area a horizontal optical reference plane or an oblique optical reference plane inclined at an arbitrary angle, said light projecting means being located at a position remote from said bulldozer and in light communication therewith; a light receiving means mounted on said tractor body portion of said bulldozer for detecting said optical reference plane formed by said light projecting means to issue a level signal to said controlling means, whereby said controlling means controls said vertical position of said blade in response thereto, said light receiving means comprising at least a pair of photo receivers arranged along said longitudinal axis of said tractor body portion of said bulldozer and spaced apart from each other and forming a tractor body reference plane, said controlling means being responsive in part to a distance between the tractor body reference plane and a tractor bearing ground surface to calculate vertical distance to be moved by said blade, said controlling means being responsive in part to a first output signal issued from one of said photo receivers at a first location on said reference plane, and a second output signal issued from the other of said photo receivers at a second location on said reference plane, said second location being longitudinally spaced from said first location, said controller.