APPARATUS FOR AND METHOD OF AUTOMATICALLY TUNING AND SETTING CONTROL PARAMETERS FOR A NUMERICAL CONTROL UNIT

An apparatus for and method of automatically tuning control parameters of a servo or spindle drive system controlled by a numerical control unit is disclosed. The numerical control unit employs an automatic tuning device that automatically selects a tuning program and test run program associated with a selected control parameter. The tuning device test runs the servo or spindle according to the test run program selected and changes and controls the status value data measured in accordance with the control parameter selected. The invention also relates to a method of changing a criterion for the feature values of a control parameter, a method of comprehensively determining the feature values where there are a plurality of tuning conditions, and a method of sampling the status value data of the servo or spindle.