System and method for detecting imbalance in a washing machine

Abstract

Systems and methods for detecting imbalance in a washing machine are disclosed. The washing machine includes a wash basket that is rotatably mounted in a wash tub. The wash basket is rotated in the wash tub during a cleansing cycle or during a spin cycle to extract water from a wash load loaded in the wash basket. The system and methods of the present disclosure include a plurality of activators mounted to the wash basket and the sensor mounted to the wash tub. The sensor can generate an activation signal each time an activator passes in front of the sensor. The activation signals can be analyzed to determine imbalance in the washing machine.

1 . A washing machine, comprising:
 a stationary wash tub;   a wash basket rotatably mounted in said wash tub, said wash basket having an outer surface facing an inner surface of said wash tub;   a sensor disposed on said inner surface of said wash tub; and   a plurality of activators mounted on the outer surface of said wash basket.   
     
     
         2 . The washing machine of  claim 1 , wherein said plurality of activators are mounted in evenly spaced apart relationship on the outer surface of said wash basket. 
     
     
         3 . The washing machine of  claim 1 , wherein each of said plurality of activators is disposed on the outer surface of said wash basket such that each of said plurality of activators passes in front of said sensor during a revolution of said wash basket within said wash tub. 
     
     
         4 . The washing machine of  claim 3 , wherein said sensor is configured to provide an activation signal each time one of said plurality activators passes in front of said sensor. 
     
     
         5 . The washing machine of  claim 3 , wherein said sensor is coupled to a controller, said sensor providing an activation signal to said controller each time one of said plurality of activators passes in front of said sensor, said controller configured to determine imbalance of said wash basket based at least in part on said activation signals. 
     
     
         6 . The washing machine of  claim 5 , wherein said controller is configured to control the rotation of said wash basket in said wash tub based at least in part on the activation signals received from said sensor. 
     
     
         7 . The washing machine of  claim 5 , wherein said controller is configured to monitor the time interval between each activation signal, said controller configured to determine imbalance in the washing machine based at least in part on the time intervals between the activation signals. 
     
     
         8 . The washing machine of  claim 1 , wherein said sensor comprises a Hall sensor. 
     
     
         9 . The washing machine of  claim 8 , wherein said plurality of activators are comprised of a magnetic material. 
     
     
         10 . A system for monitoring imbalance in a washing machine, the washing machine comprising a wash tub and a wash basket rotatably mounted in the wash tub, the wash basket having an outer surface facing an inner surface of the wash tub, the system comprising:
 a sensor mounted to the inner surface of the wash tub;   a plurality of activators mounted in evenly spaced apart relationship on the outer surface of the wash basket; and   a controller coupled to said sensor;   wherein said sensor provides an activation signal to said controller each time one of said plurality of activators passes in front of said sensor as the wash basket rotates in the wash tub.   
     
     
         11 . The system of  claim 10 , wherein said controller is configured to control rotation of the wash basket in the wash tub based at least in part on the activation signals. 
     
     
         12 . The system of  claim 10 , wherein said controller is configured to determine imbalance of the wash basket based at least in part on the activation signals. 
     
     
         13 . The system of  claim 12 , wherein said controller is configured to determine imbalance of the wash basket based on the time intervals between activation signals received from said sensor. 
     
     
         14 . The system of  claim 10 , wherein said sensor comprises a Hall sensor. 
     
     
         15 . The system of  claim 10 , wherein said plurality of activators are comprised of a magnetic material. 
     
     
         16 . A method of determining imbalance of a wash basket as it rotates in a wash tub of a washing machine, the method comprising:
 controlling the wash basket to rotate in the wash tub such that a plurality of activators mounted in evenly spaced apart relationship on the wash basket passes in front of a sensor mounted on the wash tub;   receiving an activation signal from the sensor mounted on the wash tub each time one of the plurality activators passes in front of the sensor; and   determining imbalance of the wash basket based at least in part on the activation signals.   
     
     
         17 . The method of  claim 16 , wherein the method further comprises controlling the rotation of the wash basket in the wash tub based at least in part on the activation signals. 
     
     
         18 . The method of  claim 16 , wherein determining imbalance of the wash basket comprises:
 monitoring the time intervals between activation signals; and   determining imbalance based at least in part on the time intervals between activation signals.   
     
     
         19 . The method of  claim 18 , wherein the method comprises:
 determining a degree of error of the time intervals between activation signals;   comparing the degree of error to a threshold value;   controlling the rotation of the wash basket when the degree of error exceeds the threshold value.   
     
     
         20 . The method of  claim 18 , wherein determining imbalance based at least in part on the time between activation signals comprises:
 determining a degree of error of the time intervals between activation signals;   determining imbalance as a function of the degree of error of the time between activation signals.