Adaptive control constraint ( ACC ) is applied to a turning process to keep the cutting force constant while the cutting conditions vary. In this system, a given reference force is compared with measured cutting force and the difference is in-put to the controller to adjust the feed.
Since it is found that the effective ACC loop gain depends on both depth-of-cut and spindle speed and therby influence the system stability as expectedly, a simple computer algorithm is built in the controller to maintain the stability of the whole system by on-line estimation of the process parameters during cutting.
