Motor position estimation using current ripples

A method for monitoring a motor within a seat assembly in an automotive vehicle, the method comprising the steps of:

• measuring raw current values drawn by the motor to reposition the seat assembly;
• temporally dividing the raw current values into sections based on size and variations in the raw current values;
• filtering the raw current values in each section to obtain filtered current values;
• determining a median value of the filtered current values for each section to obtain a plurality of sequential median values;
• determining a trend in the plurality of sequential median values;
• removing the trend from the plurality of sequential median values to obtain detrended values;
• determining a difference in magnitude between successive detrended values to obtain delta values;
• identifying a plurality of peaks in the delta values;
• determining which of the plurality of peaks has an amplitude greater than a threshold, wherein the peaks having an amplitude greater than the threshold correspond to detected local peaks within the filtered current values;
• and
• determining a rotational position or a speed based on the detected local peaks.

A method for extracting current ripples from raw current values drawn by a motor within a seat assembly in an automotive vehicle, the method comprising the steps of:

• measuring the raw current values drawn by the motor to reposition the seat assembly;
• temporally dividing the raw current values into sections based on size and variations in the raw current values;
• filtering the raw current values in each section to obtain filtered current values;
• and
• detecting local peaks within the filtered current values, wherein the local peaks correspond to the current ripples.