Patent ID: 8813288
Filing Date: 2014-08-26
Classification: D06F,G01M

Abstract:
1. A method for detecting an out of balance condition for a washing machine, the washing machine comprising a wash tub, a wash basket rotatably mounted within the wash tub, and a polyphase motor configured to rotate the wash basket within said wash tub, the method comprising: rotating the wash basket at a predetermined rotational speed for a data collection period; monitoring at least a single phase of motor current supplied to the motor while the wash tub rotates at the predetermined rotational speed during the data collection period; monitoring the severity of tub strikes based at least in part on the single phase motor current; wherein monitoring the severity of tub strikes comprises comparing the single phase of motor current to a current threshold and determining the deviation of the single phase of motor current from the current threshold; and detecting an excessive out of balance condition based at least in part on the severity of the tub strikes; wherein detecting an excessive out of balance condition comprises detecting an excessive out of balance condition if the deviation of the single phase of motor current exceeds a current deviation threshold.