Patent ID: 7164953

Claim:
A speed control device comprising: a speed control system including a filter delay element or a dead time delay element in a controller or a control object, the speed control system operable to carry out a PI control to follow a speed command to be a target speed V r ; a speed observer generating a speed difference V M −V MO which is a difference between a speed V M of a mechanical system and an estimated value V MO of a speed of the mechanical system; a speed observer compensator receiving the speed difference, a mechanical system model receiving sum of an output of the speed observer compensator and an output T ro of a PI controller; wherein the speed observer is constituted in such a manner that the signal V MO produced after a passage of an output of the mechanical system model though a filter delay element model and a dead time delay element model is equal to the speed V M of the mechanical system, and wherein an output of the mechanical system model is provided as a speed feedback signal V f of the speed control system.