Method of using turbidity measurements to improve rinse performance in a washing machine appliance

Abstract

A washing machine appliance includes a wash basket that is rotatably mounted within a wash tub and that defines a wash chamber for receiving a load of clothes. A motor assembly is mechanically coupled to the wash basket for selectively rotating the wash basket and a turbidity sensor is positioned within the wash fluid. A controller is configured to perform a wash cycle, obtain a turbidity of the wash fluid following the wash cycle using the turbidity sensor, determine rinse parameters of a rinse cycle based at least in part on the turbidity of the wash fluid, and perform the rinse cycle in accordance with the rinse parameters.

What is claimed is: 
     
         1 . A washing machine appliance, comprising:
 a wash tub positioned within a cabinet;   a wash basket rotatably mounted within the wash tub and defining a wash chamber configured for receiving a load of clothes;   a water supply for selectively adding wash fluid to the wash tub;   a sump positioned proximate a bottom of the wash tub for collecting the wash fluid;   a turbidity sensor positioned within the wash fluid;   a motor assembly mechanically coupled to the wash basket for selectively rotating the wash basket; and   a controller operably coupled to the water supply and the motor assembly, the controller being configured to:
 perform a wash cycle; 
 obtain a turbidity of the wash fluid following the wash cycle using the turbidity sensor; 
 determine rinse parameters of a rinse cycle based at least in part on the turbidity of the wash fluid; and 
 perform the rinse cycle in accordance with the rinse parameters. 
   
     
     
         2 . The washing machine appliance of  claim 1 , wherein performing the wash cycle comprises:
 operating the water supply to fill the wash tub with the wash fluid; and   operating the motor assembly to agitate the load of clothes.   
     
     
         3 . The washing machine appliance of  claim 1 , wherein determining the rinse parameters of the rinse cycle based at least in part on the turbidity of the wash fluid comprises:
 determining that the turbidity of the wash fluid exceeds a predetermined turbidity threshold; and   selecting enhanced rinse parameters relative to standard rinse parameters.   
     
     
         4 . The washing machine appliance of  claim 3 , wherein selecting the enhanced rinse parameters relative to the standard rinse parameters comprises:
 increasing at least one of a fill volume, a water temperature, a rinse duration, or an agitation intensity relative to the standard rinse parameters.   
     
     
         5 . The washing machine appliance of  claim 3 , wherein selecting the enhanced rinse parameters relative to the standard rinse parameters comprises:
 performing a rinse spin phase or an agitate, rinse, and drain phase during the rinse cycle.   
     
     
         6 . The washing machine appliance of  claim 1 , wherein determining the rinse parameters of the rinse cycle based at least in part on the turbidity of the wash fluid comprises:
 determining that the turbidity of the wash fluid falls below a predetermined turbidity threshold; and   selecting reduced rinse parameters relative to standard rinse parameters.   
     
     
         7 . The washing machine appliance of  claim 6 , wherein selecting the reduced rinse parameters relative to the standard rinse parameters comprises:
 reducing at least one of a fill volume, a water temperature, a rinse duration, or an agitation intensity relative to the standard rinse parameters.   
     
     
         8 . The washing machine appliance of  claim 1 , further comprising:
 a drain pump assembly in fluid communication with the sump for selectively draining the wash fluid collected within the sump, wherein the turbidity is measured after the wash cycle and before operating the drain pump assembly.   
     
     
         9 . The washing machine appliance of  claim 8 , wherein the controller is further configured to:
 operate the drain pump assembly to drain the wash fluid and the motor assembly to spin the wash basket after performing the rinse cycle.   
     
     
         10 . The washing machine appliance of  claim 1 , wherein the turbidity is measured during the wash cycle. 
     
     
         11 . The washing machine appliance of  claim 1 , wherein the turbidity sensor is positioned within the sump. 
     
     
         12 . The washing machine appliance of  claim 1 , further comprising a conductivity sensor for measuring a conductivity of the wash fluid, the controller being operably coupled to the conductivity sensor and being configured to:
 obtain a conductivity of the wash fluid following the wash cycle using the conductivity sensor;   determine rinse parameters of the rinse cycle based at least in part on the conductivity of the wash fluid; and   perform the rinse cycle in accordance with the rinse parameters.   
     
     
         13 . The washing machine appliance of  claim 1 , further comprising a pH sensor for measuring a pH of the wash fluid, the controller being operably coupled to the pH sensor and being configured to:
 obtain a pH of the wash fluid following the wash cycle using the pH sensor;   determine rinse parameters of the rinse cycle based at least in part on the pH of the wash fluid; and   perform the rinse cycle in accordance with the rinse parameters.   
     
     
         14 . The washing machine appliance of  claim 1 , wherein the washing machine appliance is a vertical axis washing machine appliance. 
     
     
         15 . A method of operating a washing machine appliance, the washing machine appliance comprising a wash basket rotatably mounted within a wash tub and defining a wash chamber configured for receiving a load of clothes, a water supply for selectively adding wash fluid to the wash tub, a motor assembly for selectively rotating the wash basket, and a turbidity sensor positioned within the wash fluid, the method comprising:
 performing a wash cycle;   obtaining a turbidity of the wash fluid following the wash cycle using the turbidity sensor;   determining rinse parameters of a rinse cycle based at least in part on the turbidity of the wash fluid; and   performing the rinse cycle in accordance with the rinse parameters.   
     
     
         16 . The method of  claim 15 , wherein determining the rinse parameters of the rinse cycle based at least in part on the turbidity of the wash fluid comprises:
 determining that the turbidity of the wash fluid exceeds a predetermined turbidity threshold; and   selecting enhanced rinse parameters relative to standard rinse parameters.   
     
     
         17 . The method of  claim 16 , wherein selecting the enhanced rinse parameters relative to the standard rinse parameters comprises:
 increasing at least one of a fill volume, a water temperature, a rinse duration, or an agitation intensity relative to the standard rinse parameters.   
     
     
         18 . The method of  claim 15 , wherein determining the rinse parameters of the rinse cycle based at least in part on the turbidity of the wash fluid comprises:
 determining that the turbidity of the wash fluid falls below a predetermined turbidity threshold; and   selecting reduced rinse parameters relative to standard rinse parameters.   
     
     
         19 . The method of  claim 18 , wherein selecting the reduced rinse parameters relative to the standard rinse parameters comprises:
 reducing at least one of a fill volume, a water temperature, a rinse duration, or an agitation intensity relative to the standard rinse parameters.   
     
     
         20 . The method of  claim 15 , wherein the washing machine appliance further comprises a drain pump assembly in fluid communication with a sump for selectively draining the wash fluid collected within the sump, wherein the turbidity is measured after the wash cycle and before operating the drain pump assembly.