System and method for detecting imbalance in a washing machine

摘要

Systems and methods for detecting an out of balance condition for a washing machine are disclosed. The wash basket of the washing machine is rotated at a constant predetermined rotational speed. If the washing machine has an unbalanced load, the wash tub will strike the cabinet as the basket rotates in the wash tub. The tub strikes cause the wash basket to lose momentum. The inverter drive control system causes the inverter to provide more current through the motor phases to the motor to maintain constant speed. From the value of the current, the severity of the tub strikes during a test period can be determined. An out of balance condition can be detected and measured based at least in part on the severity of the tub strikes.

主权项

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.