Patent ID: 8548690

Claim:
A blade control system, comprising: a lift frame vertically pivotably attached to a vehicle body; a blade supported by a tip of the lift frame; a lift cylinder configured to vertically pivot the lift frame; a blade load obtaining part configured to obtain a blade load acting on the blade; a distance calculating part configured to calculate a distance between a designed surface and a cutting edge of the blade, the designed surface formed as a three-dimensionally designed surface contour indicating a target contour of an object for dozing; a distance determining part configured to determine a magnitude relation between a first distance and a distance between the designed surface and the cutting edge of the blade and a magnitude relation between a second distance set to be less than the first distance and the distance between the designed surface and the cutting edge of the blade; and a lift cylinder controlling part configured to provide a hydraulic oil to the lift cylinder tier executing: a dozing control when the distance determining part determines that the distance between the designed surface and the cutting edge of the blade is greater than the first distance; a grading control when the distance determining part determines that the distance between the designed surface and the cutting edge of the blade is less than the second distance; and either the dozing control or the grading control when the distance determining part determines that the distance between the designed surface and the cutting edge of the blade is greater than or equal to the second distance and less than or equal to the first distance.