Apparatus and method for feedback-adjusting working condition for improving dimensional accuracy of processed workpieces

A working system comprising:

• (a) a working machine for successively processing workpieces;
• (b) machine control means for determining a working condition of said working machine on the basis of an extraneous signal, and controlling said working machine according to the determined working condition;
• (c) a measuring device for measuring actual dimensions of working portions of the workpieces processed by said working machine;
• and
• (d) a feedback compensating apparatus used with said machine control means and said measuring device, said feedback compensating apparatus including:
• determining means for determining, as the extraneous signal, a compensating value for adjusting the working condition of said working machine for the workpiece to be processed subsequently by said working machine, on the basis of the actual dimensions of the working portions of the workpieces which have been measured by said measuring device, and according to a compensation rule, the compensation rule changing such that the compensating value to be determined according to the compensation rule is less responsive to a change in the actual dimensions of the processed workpieces when a frequency of a variation in a time of measurement of the actual dimensions successively obtained by said measuring device is higher than a threshold value, and the compensating value to be determined is more responsive to the change in the actual dimensions when the frequency of the variation in the time of measurement is equal to or lower than the threshold value;
• and
• applying means for applying the compensating value to said machine control means.