Method and apparatus for determining motor velocity using edge mode hysteresis with a finite impulse response average filter

摘要

A method for determining motor velocity includes generating an edge signal including a plurality of edges. The edge signal indicates rotational travel of a motor. Edge counts in the edge signal occurring during periodic sample intervals are determined. The edge counts are filtered over a predetermined number of samples. A velocity feedback signal is generated for the motor based on the filtered edge counts. A drive unit for controlling a motor includes an edge detection unit, a position accumulator, and a velocity filter. The edge detection unit is operable to receive a motor position signal and generate an edge signal including a plurality of edges. The edge signal indicates rotational travel of the motor. A position accumulator is operable to determine edge counts in the edge signal occurring during periodic sample intervals. The velocity filter is operable to filter the edge counts over a predetermined number of samples generate a velocity feedback signal for the motor based on the filtered edge counts.