Procedure for filtering the speed feedback signal
AssigneeKone Elevator GmbH
InventorSeppo J. Ovaska
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Abstract
A procedure is disclosed for filtering the speed feedback signal in an elevator motor drive which is provided with a speed controller and in which the speed of rotation of the motor is measured. The procedure of the invention involves sampling the speed feedback signal, producing a prediction of the next sample by a predicting procedure that filters the noise in the speed feedback signal, and forming an estimate of the latest sample by delaying the prediction by a time corresponding to one sample.
Claims6
A procedure for filtering the speed feedback signal in an elevator motor drive which is provided with a speed controller and in which the speed of rotation of the motor is measured, said procedure comprising the steps of:
- sampling the speed feedback signal,
- filtering the noise component of the sampled feedback signal by means of a predictive filtering procedure so as to produce a first filtered signal comprising a prediction of the value of the next sample, and
- filtering the first filtered signal by means of a delay-producing filtering procedure so as to produce a second filtered signal having an estimate of the latest sample value by delaying the predicted sample value by a time corresponding to one sample.
Dependencies are inferred from the claim text.