Inertia estimation of servo drives with elastically attached masses

Servo drives in elevators are often controlled by a cascaded structure of PI controllers and need well adjusted parameters to achieve high dynamic and precise positioning. As commissioning is time-consuming and needs qualified personnel an automatic bringing into service is desired. For self-commissioning of the speed controller the machine inertia needs to be known and thus an estimation procedure is proposed which requires less computational power and may run on the same microprocessor as the control algorithms. Therefore the elevator structure is exploited and only a few specific frequencies are excited. This avoids using complex techniques which estimates further parameters - resulting in higher computational needs and less robustness. The proposed algorithm has been tested in simulation and shows good and robust results.