Milling machine having a non-contact leg-height measurement system

A milling machine, comprising:

• a frame;
• a left front track disposed adjacent a front end of the frame;
• a right front track disposed adjacent the front end and spaced apart from the left front track;
• a rear track disposed adjacent a rear end of the frame;
• a left front leg column including a left front actuator disposed within the left front leg column and connecting the frame and the left front track;
• a right front leg column including a right front actuator disposed within the right front leg column and connecting the frame and the right front track;
• a rear leg column including a rear actuator disposed within the rear leg column and connecting the frame and the rear track, each of the left front actuator, the right front actuator, and the rear actuator being configured to selectively adjust a height of the frame relative to the left front track, the right front track, and the rear track, respectively,
• a milling drum connected to the frame and disposed between the front end and the rear end;
• an engine configured to rotate the milling drum and propel the left front track, the right front track, and the rear track in a forward or rearward direction;
• at least one non-contact sensor attached to the frame and configured to generate at least one signal indicative of the height of the frame relative to at least one of the left front track, the right front track, and the rear track, the non-contact sensor being disposed outside the left leg column, the right leg column, and the rear leg column;
• and
• a controller configured to determine heights of the frame relative to the at least one of the left front track, the right front track and the rear track based on the at least one signal.