Method and system for determining a position of a rotor of an electric motor with noise reduction

A method of determining a position of a rotor in a motor with reduced noise, the method comprising:

• storing a plurality of previous position readings of the rotor for a previous cycle of a pulse width modulation signal applied to the motor, the previous position readings comprising a previous cycle final selected position and previous cycle raw position;
• receiving a current raw position reading for the current cycle of the pulse width modulation signal;
• determining a predicted position reading for a current cycle based on the stored previous position readings of the previous cycle in accordance with a first mode or a second mode, where the first mode uses the previous cycle final selected position and where the second mode uses the previous cycle raw position;
• determining whether a difference between at least one of the predicted positions based on previous position readings and the current raw position reading is within a preset threshold;
• and
• selecting the current raw position reading as a verified reliable final position reading of current cycle if the difference is equal to or less than the preset threshold.

A system of determining a position of a rotor in a motor, the system comprising:

• a data storage device for storing a plurality of previous position readings of the rotor for a previous cycle of a pulse width modulation signal applied to the motor, the previous position readings comprising a previous cycle final selected position and a previous cycle raw position;
• a data port for receiving a current raw position reading for the current cycle from a sensor;
• a data processor for executing software instructions within a primary processing module for determining a predicted position reading for a current cycle based on at least one of the plurality of stored previous position readings of the previous cycle, the predicted position reading comprising the previous cycle final selected position for a first mode and the previous cycle raw position for a second mode, the primary processing module comprising the software instructions stored in the data storage device on a non-transitory basis and adapted to cause the data processor to determine whether a difference between the current raw position reading and the predicted position reading for the first mode and the second mode is within a preset threshold, the primary processing module adapted to select the current raw position reading as a verified reliable final position reading if the difference is equal to or less than the preset threshold.