Grade control system and method for a work vehicle

A method of controlling a ground-engaging blade of a work vehicle comprising:

• receiving a chassis inclination signal indicative of an angle of a chassis of the work vehicle relative to the direction of gravity;
• receiving a blade inclination signal indicative of an angle of the blade relative to one of the chassis and the direction of gravity;
• determining a target grade;
• determining a first relative distance between a point on a linkage assembly connecting the blade to the chassis and the target grade based on the chassis inclination signal;
• determining a second relative distance between a point on the blade and the point of the linkage assembly based on the blade inclination signal;
• determining a distance error indicative of a distance between the blade and the target grade based on the chassis inclination signal, the blade inclination signal, the first relative distance, and the second relative distance;
• and
• determining a command signal to direct movement of the blade toward the target grade based on the distance error.

A crawler-dozer comprising:

• a chassis;
• a ground-engaging blade movably connected to the chassis by a linkage assembly configured to allow the blade to be raised and lowered relative to the chassis;
• a hydraulic cylinder;
• an electrohydraulic valve assembly configured to move the blade by directing hydraulic fluid to the hydraulic cylinder;
• a first sensor connected to the chassis at a fixed relative position to the chassis, the first sensor configured to provide a chassis inclination signal indicative of an angle of the chassis relative to the direction of gravity;
• a second sensor connected to the blade at a fixed relative position to the blade, the second sensor configured to provide a blade inclination signal indicative of an angle of the blade relative to one of the chassis and the direction of gravity;
• and
• a controller configured to:
• receive the chassis inclination signal;
• receive the blade inclination signal;
• determine a target grade;
• determine a first relative distance between a point on the linkage assembly about which the linkage assembly pivots relative to the chassis and the target grade based on the chassis inclination signal;
• determine a second relative distance between a point on the blade and the point on the linkage assembly based on the blade inclination signal;
• determine a distance error based on the chassis inclination signal, the blade inclination signal, the first relative distance, and the second relative distance, the distance error indicative of a distance between the blade and the target grade;
• determine a command signal directing movement of the blade toward the target grade based on the distance error;
• and
• send the command signal to the electrohydraulic valve assembly.