Abstract: A milling machine includes a milling assembly having a housing to which left and right end gates are attached, a controller, a right front lifting column, a left front lifting column and a rear lifting column. Elevation sensors are located at the front and rear of each of the end gates. The controller is operatively attached to the elevation sensors and to linear actuators within the lifting columns of the milling machine. The elevation sensor that is located at the front end of the right end gate will provide feedback to control the position of the right front lifting column, and the elevation sensor that is located at the front end of the left end gate will provide feedback to control the position of the left front lifting column. The elevation sensors that are located at the rear ends of the end gates are available, as selected by the operator, to provide feedback to control the positions of one of the right and left front lifting columns, as well as the rear lifting column.

Abstract: A milling machine includes a milling assembly having a housing to which left and right end gates are attached, a controller, a right front lifting column, a left front lifting column and a rear lifting column. Elevation sensors are located at the front and rear of each of the end gates. The controller is operatively attached to the elevation sensors and to linear actuators within the lifting columns of the milling machine. The elevation sensor that is located at the front end of the right end gate will provide feedback to control the position of the right front lifting column, and the elevation sensor that is located at the front end of the left end gate will provide feedback to control the position of the left front lifting column. The elevation sensors that are located at the rear ends of the end gates are available, as selected by the operator, to provide feedback to control the positions of one of the right and left front lifting columns, as well as the rear lifting column.

Abstract: A working machine such as a road milling machine of an asphalt paving machine has an automatic grade and slope control system that causes the machine to maintain a pre-selected grade and slope with respect to a reference without significant operator input. A calibration system employs a calibration controller to calibrate the automatic grade and slope control system. The calibration controller causes a current to be sent to a valve that operates a linear actuator that may be employed to change the attitude of the frame of the working machine. The calibration controller uses feedback from at least one sensor, such as a height-measuring sensor or a slope-measuring sensor, in an iterative process that determines the minimum current necessary to cause a change in the attitude of the frame of the working machine. Once this minimum value is determined, the system will establish the optimum settings for the automatic grade and slope control system to improve its efficiency and cause it to operate more smoothly.

Abstract: A working machine such as a road milling machine of an asphalt paving machine has an automatic grade and slope control system that causes the machine to maintain a pre-selected grade and slope with respect to a reference without significant operator input. A calibration system employs a calibration controller to calibrate the automatic grade and slope control system. The calibration controller causes a current to be sent to a valve that operates a linear actuator that may be employed to change the attitude of the frame of the working machine. The calibration controller uses feedback from at least one sensor, such as a height-measuring sensor or a slope-measuring sensor, in an iterative process that determines the minimum current necessary to cause a change in the attitude of the frame of the working machine. Once this minimum value is determined, the system will establish the optimum settings for the automatic grade and slope control system to improve its efficiency and cause it to operate more smoothly.