GRADING CONTROL SYSTEM USING MACHINE LINKAGES

A grading control system (70) is disclosed. The grading control system may have a lift actuator (40) to raise or lower a work implement (38, 64), and a tilt actuator (42) to tilt the work implement. The grading control system may also have a first sensor (76) that communicates a signal indicative of a position of the work implement, and a second sensor (78) that communicates a signal indicative of a position of the machine frame. The grading control system may have a controller (74) to determine a track plane (120) of the machine and a desired grade relative to the track plane. Further, the controller may determine an orientation of the work implement relative to the track plane to maintain the desired grade based on the sensor signals. The controller may also be configured to actuate one or both of the lift and the tilt actuators to orient the work implement according to the determined orientation.