Control constant adjusting apparatus

A control constant adjusting apparatus comprising:

• a command generation member for outputting a speed command (Vref),
• a speed control member for inputting the speed command (Vref) and an actual motor speed (Vfb) and calculating a speed deviation (Ve) by subtracting the actual motor speed (Vfb) from the speed command (Vref) and calculating a speed proportional integral value by adding an integral term for calculating a speed integral value by integrating the speed deviation (Ve) with respect to an integral time constant (Ti) to a proportional term for calculating a speed proportional value by subtracting the motor speed (Vfb) from a value in which the speed command (Vref) is multiplied by a predetermined constant α (α≧0) and determining a torque command (Tref) by multiplying the speed proportional integral value by an inertia estimation value (J) for estimating a total value of a motor inertia value (Jm) and a load inertia value (JL) and controlling the motor speed by the torque command,
• an estimation member for simulating the speed control member so that a speed (Vfb′)of a model matches with the motor speed (Vfb),
• an identification member for providing a feedforward compensation function for adding the speed proportional integral value in the speed control member to a model speed proportional integral value similarly computed in the estimation member and setting the speed proportional integral value to a new model speed proportional integral value, and making identification of inertia (J) obtained from a ratio between a value (|SFTr|) in which an absolute value (|FTr|) of a value (FTr) obtained by passing the torque command (Tref) of the speed control member through a predetermined high-pass filter is integrated with respect to time at a predetermined interval ([a, b]) and a value (|SFTr′|) in which an absolute value (|FTr′|) of a value (FTr′) obtained by passing a model torque command (Tref′) of the estimation member through a predetermined high-pass filter is integrated with respect to time at the same interval, and
• an adjustment member for adjusting a control gain based on a ratio (J/J′) between the inertia estimation value (J) identified in the identification member and inertia (J′) in the estimation member.