Method and apparatus for preventing an imbalance in a laundry treating appliance

Abstract

An apparatus and method for preventing an imbalance for a laundry treating appliance.

1 . A method for operating a laundry treating appliance having a rotating drum defining a treating chamber for receiving a laundry load formed of multiple articles for treatment, a motor rotating the drum, and a controller operably coupled to the motor to control the rotation of the treating chamber according to a cycle of operation, the method comprising:
 a) rotating the drum according to a speed profile;   b) determining a magnitude of an imbalance in the drum during the rotating of the drum;   c) determining a location of an imbalance in the drum during the rotating of the drum; and   d) altering the rotation of the drum from the speed profile to form a counterbalance to the imbalance with a subset of the multiple articles forming the laundry load.   
     
     
         2 . The method of  claim 1  wherein the forming the counterbalance is accomplished without stopping or reversing the rotation of the treating chamber. 
     
     
         3 . The method of  claim 1  wherein the forming the counterbalance comprises forming the counterbalance substantially diametrically opposite to the imbalance. 
     
     
         4 . The method of  claim 1  wherein the determining the magnitude of the imbalance comprises monitoring a signal of the motor torque in the frequency domain. 
     
     
         5 . The method of  claim 4  wherein monitoring the signal in the frequency domain comprises monitoring a frequency representative of the rotational speed of the drum. 
     
     
         6 . The method of  claim 1  wherein the speed profile comprises at least one of an acceleration phase and a constant speed phase. 
     
     
         7 . The method of  claim 1  wherein altering the rotation of the drum from the speed profile comprises temporarily accelerating the drum out of phase with the location of the imbalance. 
     
     
         8 . The method of  claim 7  wherein the temporarily accelerating the drum occurs when the imbalance is located near the highest point of rotation within the drum. 
     
     
         9 . The method of  claim 8  wherein the temporarily accelerating the drum occurs when the imbalance is located within 90 degrees of the highest point of rotation within the drum. 
     
     
         10 . The method of  claim 7  wherein the temporarily accelerating the drum out of phase comprises temporarily accelerating the drum approximately 180 degrees out of phase with the location of the imbalance. 
     
     
         11 . The method of  claim 10  wherein the temporarily accelerating the drum begins within 90 degrees out of phase with the location of the imbalance. 
     
     
         12 . The method of  claim 11  wherein the temporarily accelerating the drum ends within 270 degrees out of phase with the location of the imbalance. 
     
     
         13 . The method of  claim 7  wherein the altering the rotation of the drum comprises applying a sinusoidal acceleration profile onto the speed profile with the sinusoidal acceleration profile that is approximately 180 degrees out of phase with the location of the imbalance. 
     
     
         14 . A method for operating a laundry treating appliance having a rotating drum defining a treating chamber for receiving a laundry load formed of multiple articles for treatment, a motor rotating the drum, and a controller operably coupled to the motor to control the rotation of the treating chamber according to a cycle of operation, the method comprising:
 a) rotating the drum according to a speed profile;   b) determining a location of an imbalance in the drum during the rotating of the drum; and   c) accelerating the drum according to an acceleration profile applied on top of the speed profile, where the acceleration profile is approximately 180 degrees out of phase with the determined location of the drum.   
     
     
         15 . The method of  claim 14  wherein the speed profile comprises an acceleration phase and the acceleration profile is applied on top of the speed profile during the acceleration phase. 
     
     
         16 . The method of  claim 15  wherein the greatest acceleration of the acceleration profile occurs when the imbalance is located near the highest point of rotation within the drum. 
     
     
         17 . The method of  claim 16  wherein the acceleration profile comprises a sinusoid applied to the speed profile. 
     
     
         18 . A laundry treating appliance, comprising:
 a rotatable drum defining a treating chamber for receiving a laundry load comprising multiple items for treatment;   a motor operably coupled to the rotatable treating chamber to drivingly rotate the treating chamber; and   a controller operably coupled to the motor and rotating the drum according to a speed profile and accelerating the drum according to an acceleration profile applied on top of the speed profile, where the acceleration profile is approximately 180 degrees out of phase with a location of an imbalance in the treating chamber.   
     
     
         19 . The laundry treating appliance of  claim 17  wherein the controller further comprises an imbalance location program for detecting the location of the imbalance within the treating chamber relative to a position of the drum. 
     
     
         20 . The laundry treating appliance of  claim 17  wherein the acceleration profile comprises a sinusoid applied to the speed profile.