CPC E06B 9/72 (2013.01) [E06B 9/42 (2013.01); H02K 7/108 (2013.01); H02K 29/08 (2013.01); H02P 6/21 (2016.02); E06B 2009/6827 (2013.01); H02K 2207/03 (2013.01)] | 21 Claims |
1. A motorized shade for selectively covering an architectural opening comprising:
a roller tube;
a shade material connected to the roller tube;
a motor adapted to rotate the roller tube to raise or lower the shade material between an upper limit and a lower limit, wherein the motor comprises a rotor and a stator comprising at least one phase; and
a controller adapted to control the motor to move the shade material by an incremental distance, wherein for at least one motor phase to move the shade material by the incremental distance the controller is adapted to:
drive the motor phase according to an amplitude ramping curve comprising amplitude that increases from an initial amplitude to a startup amplitude;
drive the motor phase from the startup amplitude according to a sinusoidal waveform comprising a set maximum amplitude and an initial frequency;
ramp up frequency of the sinusoidal waveform from the initial frequency to the drive frequency; and
drive the motor phase according to the sinusoidal waveform at the set maximum amplitude and the drive frequency.
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