Washing machine appliances and methods of operation

Abstract

A washing machine appliance, including one or more methods of operation, is provided herein. A method of operation may include rotating articles within a tub at a tumble speed for a first period and rotating articles within the tub at a pre-plaster speed for a second period following the first period. The pre-plaster speed may be greater than the tumble speed. The method may also include measuring movement of the tub during the second period. The method may further include determining whether a set condition is met based on the measured movement, and rotating articles within the tub at a plaster speed in response to determining the set condition is met based on the measured movement.

What is claimed is: 
     
         1 . A method for operating a washing machine appliance, the washing machine appliance having a tub, the method comprising:
 rotating articles within the tub at a tumble speed for a first period;   rotating articles within the tub at a pre-plaster speed for a second period following the first period, the pre-plaster speed being greater than the tumble speed;   measuring movement of the tub during the second period;   determining an out-of-balance value of the tub based on the measured movement;   determining whether a set condition is met based on the determined out-of-balance value; and   rotating articles within the tub at a plaster speed in response to determining the set condition is met based on the determined out-of-balance value.   
     
     
         2 . The method of  claim 1 , wherein the measured movement is movement along a lateral direction. 
     
     
         3 . The method of  claim 2 , wherein the measured movement is movement perpendicular to an axis of rotation within the tub. 
     
     
         4 . The method of  claim 1 , wherein determining the out-of-balance value comprises calculating the out-of-balance value as a function of a rotational velocity within the washing machine appliance. 
     
     
         5 . The method of  claim 1 , wherein measuring movement comprises measuring displacement at an effective center of gravity, wherein the effective center of gravity is offset from a geometric center of gravity along a transverse direction. 
     
     
         6 . The method of  claim 5 , wherein the transverse direction is parallel to an axis of rotation within the tub. 
     
     
         7 . The method of  claim 1 , wherein determining an out-of-balance value comprises determining a plurality of out-of-balance values, wherein the method further comprises determining a rate of change across the plurality of out-of-balance values, and wherein the set condition comprises the rate of change being below a set rate threshold. 
     
     
         8 . The method of  claim 1 , further comprising reducing rotational velocity in response to the set condition not being met. 
     
     
         9 . The method of  claim 1 , further comprising rotating articles within the tub at the pre-plaster speed for a third period in response to the set condition not being met. 
     
     
         10 . The method of  claim 9 , further comprising:
 measuring movement of the tub during the third period;   determining an additional out-of-balance value of the tub based on the measured movement during the third period;   determining whether the set condition is met based on the determined additional out-of-balance value; and   rotating articles within the tub at the plaster speed in response to determining the set condition is met based on the determined additional out-of-balance value.   
     
     
         11 . A method for operating a washing machine appliance, the washing machine appliance defining a mutually-orthogonal vertical direction, transverse direction, lateral direction, the washing machine appliance having a tub within which an axis of rotation is defined, the method comprising:
 rotating articles within the tub at a tumble speed for a first period;   rotating articles within the tub at a pre-plaster speed for a second period following the first period, the pre-plaster speed being greater than the tumble speed;   measuring movement of the tub along the lateral direction during the second period, the lateral direction being perpendicular to the axis of rotation;   determining whether a set condition is met based on the measured movement; and   rotating articles within the tub at a plaster speed in response to determining the set condition is met based on the measured movement.   
     
     
         12 . The method of  claim 11 , further comprising determining an out-of-balance value of the tub based on the measured movement, wherein determining whether the set condition is met is based on the determined out-of-balance value. 
     
     
         13 . The method of  claim 12 , wherein determining the out-of-balance value comprises calculating the out-of-balance value as a function of a rotational velocity within the washing machine appliance. 
     
     
         14 . The method of  claim 13 , wherein determining an out-of-balance value comprises determining a plurality of out-of-balance values, wherein the method further comprises determining a rate of change across the plurality of out-of-balance values, and wherein the set condition comprises the rate of change being below a set rate threshold. 
     
     
         15 . The method of  claim 11 , wherein measuring movement comprises measuring displacement at an effective center of gravity, wherein the effective center of gravity is offset from a geometric center of gravity along the transverse direction. 
     
     
         16 . The method of  claim 11 , wherein the transverse direction is parallel to an axis of rotation within the tub. 
     
     
         17 . The method of  claim 11 , further comprising reducing rotational velocity in response to the set condition not being met. 
     
     
         18 . The method of  claim 11 , further comprising rotating articles within the tub at the pre-plaster speed for a third period in response to the set condition not being met. 
     
     
         19 . The method of  claim 18 , further comprising:
 measuring movement of the tub during the third period;   determining whether the set condition is met based on the measured movement during the third period; and   rotating articles within the tub at the plaster speed in response to determining the set condition is met based on the measured movement during the third period.