A control constant adjusting apparatus in a control apparatus of a robot
or a machine tool, etc. is disclosed. This control constant adjusting
apparatus includes a speed control part (12), an estimation part (13), an
identification part (14) and an adjustment part (15) . The identification
part (14) makes identification of inertia J obtained from a ratio between
a value .vertline.SFTr.vertline. in which an absolute value
.vertline.FTr.vertline. of a value FTr obtained by passing a torque
command Tref of the speed control part (12) through a predetermined
high-pass filter is integrated with respect to time at a predetermined
interval [a, b] and a value .vertline.SFTr'.vertline. in which an
absolute value .vertline.Ftr'.vertline. of a value FTr' obtained by
passing a model torque command Tref' of the estimation part (13) through
a predetermined high-pass filter is integrated with respect to time at
the same interval only when a speed Vfb' of a model in the estimation
part (13) matches with a motor speed Vfb in the speed control part (12)
at a value other than zero.
