Patent attributes
A multiple-point smoothing method for motor-speed estimation. The output of an encoder is over-sampled to obtain over-sampled position differences according to an over-sampling factor M. The over-sampled position differences are averaged to obtain an initial speed estimation. The initial speed estimation is low-pass filtered to obtain a final speed estimation. The final speed estimation is sent to a speed controller to control the speed of a motor. Alternatively, in a composite multiple-point smoothing scheme, the initial speed estimations based on two over-sampling factors are obtained. One of the initial speed estimations is selected based on an average of the two estimations, and the selected initial speed estimation is further processed to obtain a final speed estimation. The method of the present invention can reduce ripple in estimated speed of motor when the motor is operated at high speed.
