METHOD OF USING TURBIDITY MEASUREMENTS TO IMPROVE PERFORMANCE OF A WASHING MACHINE APPLIANCE

Abstract

A washing machine appliance includes a wash basket that is rotatably mounted within a wash tub. A water supply is provided for selectively adding wash fluid to the wash tub, 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 operate the water supply to dispense a target volume of the wash fluid, perform an additive mixing cycle to agitate wash additive within the target volume of the wash fluid, obtain a first turbidity measurement, perform an agitation cycle with the target volume of the wash fluid, obtain a second turbidity measurement, and complete a wash cycle at the a wash cycle intensity determined a based at least in part on the first turbidity and the second turbidity.

Description

FIELD OF THE INVENTION

The present subject matter relates generally to washing machine appliances, or more specifically, to methods for using turbidity measurements to improve the wash performance in a washing machine appliance.

BACKGROUND OF THE INVENTION

Washing machine appliances generally include a tub for containing water or wash fluid, e.g., water and detergent, bleach, and/or other wash additives. A basket is rotatably mounted within the tub and defines a wash chamber for receipt of articles for washing. During normal operation of such washing machine appliances, the wash fluid is directed into the tub and onto articles within the wash chamber of the basket. The basket or an agitation element can rotate at various speeds to agitate articles within the wash chamber, to wring wash fluid from articles within the wash chamber, etc. During a spin or drain cycle, a drain pump assembly may operate to discharge water from within sump.

Conventional washing machines may permit the user to select a soil level associated with a particular wash cycle, e.g., with higher soil selections resulting in a longer and more aggressive agitation process to properly clean the clothes. However, users often select the incorrect soil level or do not know the soil level for a particular load of clothes. Accordingly, washing machines commonly over-wash clothes, resulting in unnecessary wear on clothes and longer cycle times. By contrast, if the selected soil level is low and the clothes are very dirty, the cleaning cycle may under-wash the clothes, leaving behind soils and resulting in user dissatisfaction.

Accordingly, a washing machine appliance with improved wash performance is desirable. More specifically, a method for detecting soil levels and selecting an appropriate wash cycle parameters while reducing cycle time and improving user satisfaction would be particularly beneficial.

BRIEF DESCRIPTION OF THE INVENTION

Advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In one exemplary embodiment, a washing machine appliance is provided including 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 is configured to operate the water supply to dispense a target volume of the wash fluid into the wash tub, operate the motor assembly to perform an additive mixing cycle to agitate wash additive within the target volume of the wash fluid, obtain a first turbidity of the wash fluid using the turbidity sensor, operate the motor assembly to perform an agitation cycle with the target volume of the wash fluid, obtain a second turbidity of the wash fluid using the turbidity sensor, determine a wash cycle intensity based at least in part on the first turbidity and the second turbidity, and complete a wash cycle at the determined wash cycle intensity.

In another exemplary embodiment, a method of operating a washing machine appliance is provided. The washing machine appliance includes a wash basket rotatably mounted within a wash tub, a water supply for selectively adding wash fluid to the wash tub, a turbidity sensor positioned within the wash fluid, and a motor assembly mechanically coupled to the wash basket for selectively rotating the wash basket. The method includes operating the water supply to dispense a target volume of the wash fluid into the wash tub, operating the motor assembly to perform an additive mixing cycle to agitate wash additive within the target volume of the wash fluid, obtaining a first turbidity of the wash fluid using the turbidity sensor, operating the motor assembly to perform an agitation cycle with the target volume of the wash fluid, obtaining a second turbidity of the wash fluid using the turbidity sensor, determining a wash cycle intensity based at least in part on the first turbidity and the second turbidity, and completing a wash cycle at the determined wash cycle intensity.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides a perspective view of a washing machine appliance according to an exemplary embodiment of the present subject matter with a door of the exemplary washing machine appliance shown in a closed position.

FIG. 2 provides a perspective view of the exemplary washing machine appliance of FIG. 1 with the door of the exemplary washing machine appliance shown in an open position.

FIG. 3 provides a side cross-sectional view of the exemplary washing machine appliance of FIG. 1.

FIG. 4 illustrates a method for operating a washing machine appliance in accordance with one embodiment of the present disclosure.

FIG. 5 provides a flow diagram of an exemplary process for implementing a turbidity-based wash cycle method in a washing machine appliance according to an exemplary embodiment of the present subject matter.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). In addition, here and throughout the specification and claims, range limitations may be combined and/or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.

Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “generally,” “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components and/or systems. For example, the approximating language may refer to being within a 10 percent margin, i.e., including values within ten percent greater or less than the stated value. In this regard, for example, when used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction, e.g., “generally vertical” includes forming an angle of up to ten degrees in any direction, e.g., clockwise or counterclockwise, with the vertical direction V.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” In addition, references to “an embodiment” or “one embodiment” does not necessarily refer to the same embodiment, although it may. Any implementation described herein as “exemplary” or “an embodiment” is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIGS. 1 through 3 illustrate an exemplary embodiment of a vertical axis washing machine appliance 100. Specifically, FIGS. 1 and 2 illustrate perspective views of washing machine appliance 100 in a closed and an open position, respectively. FIG. 3 provides a side cross-sectional view of washing machine appliance 100. Washing machine appliance 100 generally defines a vertical direction V, a lateral direction L, and a transverse direction T, each of which is mutually perpendicular, such that an orthogonal coordinate system is generally defined.

While described in the context of a specific embodiment of vertical axis washing machine appliance 100, it should be appreciated that vertical axis washing machine appliance 100 is provided by way of example only. It will be understood that aspects of the present subject matter may be used in any other suitable washing machine appliance, such as a horizontal axis washing machine appliance. Indeed, modifications and variations may be made to washing machine appliance 100, including different configurations, different appearances, and/or different features while remaining within the scope of the present subject matter.

Washing machine appliance 100 has a cabinet 102 that extends between a top portion 104 and a bottom portion 106 along the vertical direction V, between a first side (left) and a second side (right) along the lateral direction L, and between a front and a rear along the transverse direction T. As best shown in FIG. 3, a wash tub 108 is positioned within cabinet 102, defines a wash chamber 110, and is generally configured for retaining wash fluids during an operating cycle. Washing machine appliance 100 further includes a primary dispenser or dispensing assembly 112 (FIG. 2) for dispensing wash fluid into wash tub 108.

In addition, washing machine appliance 100 includes a wash basket 114 that is positioned within wash tub 108 and generally defines an opening 116 for receipt of articles for washing. More specifically, wash basket 114 is rotatably mounted within wash tub 108 such that it is rotatable about an axis of rotation A. According to the illustrated embodiment, the axis of rotation A is substantially parallel to the vertical direction V. In this regard, washing machine appliance 100 is generally referred to as a “vertical axis” or “top load” washing machine appliance 100. However, it should be appreciated that aspects of the present subject matter may be used within the context of a horizontal axis or front load washing machine appliance as well.

As illustrated, cabinet 102 of washing machine appliance 100 has a top panel 118. Top panel 118 defines an opening (FIG. 2) that coincides with opening 116 of wash basket 114 to permit a user access to wash basket 114. Washing machine appliance 100 further includes a door 120 which is rotatably mounted to top panel 118 to permit selective access to opening 116. In particular, door 120 selectively rotates between the closed position (as shown in FIGS. 1 and 3) and the open position (as shown in FIG. 2). In the closed position, door 120 inhibits access to wash basket 114. Conversely, in the open position, a user can access wash basket 114. A window 122 in door 120 permits viewing of wash basket 114 when door 120 is in the closed position, e.g., during operation of washing machine appliance 100. Door 120 also includes a handle 124 that, e.g., a user may pull and/or lift when opening and closing door 120. Further, although door 120 is illustrated as mounted to top panel 118, door 120 may alternatively be mounted to cabinet 102 or any other suitable support.

As best shown in FIGS. 2 and 3, wash basket 114 further defines a plurality of perforations 126 to facilitate fluid communication between an interior of wash basket 114 and wash tub 108. In this regard, wash basket 114 is spaced apart from wash tub 108 to define a space for wash fluid to escape wash chamber 110. During a spin cycle, wash fluid within articles of clothing and within wash chamber 110 is urged through perforations 126 wherein it may collect in a sump 128 defined by wash tub 108. Washing machine appliance 100 further includes a pump assembly 130 (FIG. 3) that is located beneath wash tub 108 and wash basket 114 for gravity assisted flow when draining wash tub 108.

An impeller or agitation element 132 (FIG. 3), such as a vane agitator, impeller, auger, oscillatory basket mechanism, or some combination thereof is disposed in wash basket 114 to impart an oscillatory motion to articles and liquid in wash basket 114. More specifically, agitation element 132 extends into wash basket 114 and assists agitation of articles disposed within wash basket 114 during operation of washing machine appliance 100, e.g., to facilitate improved cleaning. In different embodiments, agitation element 132 includes a single action element (i.e., oscillatory only), a double action element (oscillatory movement at one end, single direction rotation at the other end) or a triple action element (oscillatory movement plus single direction rotation at one end, single direction rotation at the other end). As illustrated in FIG. 3, agitation element 132 and wash basket 114 are oriented to rotate about axis of rotation A (which is substantially parallel to vertical direction V).

As best illustrated in FIG. 3, washing machine appliance 100 includes a drive assembly or motor assembly 138 in mechanical communication with wash basket 114 to selectively rotate wash basket 114 (e.g., during an agitation or a rinse cycle of washing machine appliance 100). In addition, motor assembly 138 may also be in mechanical communication with agitation element 132. In this manner, motor assembly 138 may be configured for selectively rotating or oscillating wash basket 114 and/or agitation element 132 during various operating cycles of washing machine appliance 100.

More specifically, motor assembly 138 may generally include one or more of a drive motor 140 and a transmission assembly 142, e.g., such as a clutch assembly, for engaging and disengaging wash basket 114 and/or agitation element 132. According to the illustrated embodiment, drive motor 140 is a brushless DC electric motor, e.g., a pancake motor. However, according to alternative embodiments, drive motor 140 may be any other suitable type or configuration of motor. For example, drive motor 140 may be an AC motor, an induction motor, a permanent magnet synchronous motor, or any other suitable type of motor. In addition, motor assembly 138 may include any other suitable number, types, and configurations of support bearings or drive mechanisms.

Referring still to FIGS. 1 through 3, a control panel 150 with at least one input selector 152 (FIG. 1) extends from top panel 118. Control panel 150 and input selector 152 collectively form a user interface input for operator selection of machine cycles and features. A display 154 of control panel 150 indicates selected features, operation mode, a countdown timer, and/or other items of interest to appliance users regarding operation.

Operation of washing machine appliance 100 is controlled by a controller or processing device 156 that is operatively coupled to control panel 150 for user manipulation to select washing machine cycles and features. In response to user manipulation of control panel 150, controller 156 operates the various components of washing machine appliance 100 to execute selected machine cycles and features. According to an exemplary embodiment, controller 156 may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with methods described herein. Alternatively, controller 156 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software. Control panel 150 and other components of washing machine appliance 100 may be in communication with controller 156 via one or more signal lines or shared communication busses.

During operation of washing machine appliance 100, laundry items are loaded into wash basket 114 through opening 116, and washing operation is initiated through operator manipulation of input selectors 152. Wash basket 114 is filled with water and detergent and/or other fluid additives via primary dispenser 112. One or more valves can be controlled by washing machine appliance 100 to provide for filling wash tub 108 and wash basket 114 to the appropriate level for the amount of articles being washed and/or rinsed. By way of example for a wash mode, once wash basket 114 is properly filled with fluid, the contents of wash basket 114 can be agitated (e.g., with agitation element 132 as discussed previously) for washing of laundry items in wash basket 114.

Referring again to FIGS. 2 and 3, dispensing assembly 112 of washing machine appliance 100 will be described in more detail. As explained briefly above, dispensing assembly 112 may generally be configured to dispense wash fluid to facilitate one or more operating cycles or phases of an operating cycle (e.g., such as a wash cycle or a rinse cycle). The terms “wash fluid” and the like may be used herein to generally refer to a liquid used for washing and/or rinsing clothing or other articles. For example, the wash fluid is typically made up of water that may include other additives such as detergent, fabric softener, bleach, or other suitable treatments (including combinations thereof). More specifically, the wash fluid for a wash cycle may be a mixture of water, detergent, and/or other additives, while the wash fluid for a rinse cycle may be water only.

As best shown schematically in FIG. 3, dispensing assembly 112 may generally include a bulk storage tank or bulk reservoir 158 and a dispenser box 160. More specifically, bulk reservoir 158 may be positioned under top panel 118 and defines an additive reservoir for receiving and storing wash additive. More specifically, according to the illustrated embodiment, bulk reservoir 158 may contain a bulk volume of wash additive (such as detergent or other suitable wash additives) that is sufficient for a plurality of wash cycles of washing machine appliance 100, such as no less than twenty wash cycles, no less than fifty wash cycles, etc. As a particular example, bulk reservoir 158 is configured for containing no less than twenty fluid ounces, no less than three-quarters of a gallon, or about one gallon of wash additive.

As will be described in detail below, dispensing assembly 112 may include features for drawing wash additive from bulk reservoir 158 and mixing it with water prior to directing the mixture into wash tub 108 to facilitate a cleaning operation. By contrast, dispensing assembly 112 is also capable of dispensing water only. Thus, dispensing assembly 112 may automatically dispense the desired amount of water with or without a desired amount of wash additive such that a user can avoid filling dispenser box 160 with detergent before each operation of washing machine appliance 100.

For example, as best shown in FIG. 3, washing machine appliance 100 includes an aspirator assembly 162, which is a Venturi-based dispensing system that uses a flow of water to create suction within a Venturi tube to draw in wash additive from bulk reservoir 158 which mixes with the water and is dispensed into wash tub 108 as a concentrated wash fluid preferably having a target volume of wash additive. After the target volume of wash additive is dispensed into wash tub 108, additional water may be provided into wash tub 108 as needed to fill to the desired wash volume. It should be appreciated that the target volume may be preprogrammed in controller 156 according to the selected operating cycle or parameters, may be set by a user, or may be determined in any other suitable manner.

As illustrated, aspirator assembly 162 includes a Venturi pump 164 that is fluidly coupled to both a water supply conduit 166 and a suction line 168. As illustrated, water supply conduit 166 may provide fluid communication between a water supply source 170 (such as a municipal water supply) and a water inlet of Venturi pump 164. In addition, washing machine appliance 100 includes a water fill valve or water control valve 172 which is operably coupled to water supply conduit 166 and is communicatively coupled to controller 156. In this manner, controller 156 may regulate the operation of water control valve 172 to regulate the amount of water that passes through aspirator assembly 162 and into wash tub 108.

In addition, suction line 168 may provide fluid communication between bulk reservoir 158 and Venturi pump 164 (e.g., via a suction port defined on Venturi pump 164). Notably, as a flow of water is supplied through Venturi pump 164 to wash tub 108, the flowing water creates a negative pressure within suction line 168. This negative pressure may draw in wash additive from bulk reservoir 158. When certain conditions exist, the amount of wash additive dispensed is roughly proportional to the amount of time water is flowing through Venturi pump 164.

Referring still to FIG. 3, aspirator assembly 162 may further include a suction valve 174 that is operably coupled to suction line 168 to control the flow of wash additive through suction line 168 when desired. For example, suction valve 174 may be a solenoid valve that is communicatively coupled with controller 156. Controller 156 may selectively open and close suction valve 174 to allow wash additive to flow from bulk reservoir 158 through additive suction valve 174. For example, during a rinse cycle where only water is desired, suction valve 174 may be closed to prevent wash additive from being dispensed through suction valve 174. In some embodiments, suction valve 174 is selectively controlled based on at least one of the selected wash cycle, the soil level of the articles to be washed, and the article type. According to still other embodiments, no suction valve 174 is needed at all and alternative means for preventing the flow of wash additive may be used or other water regulating valves may be used to provide water into wash tub 108.

Washing machine appliance 100, or more particularly, dispensing assembly 112, generally includes a discharge nozzle 176 for directing a flow of wash fluid (e.g., identified herein generally by reference numeral 178) into wash chamber 108. In this regard, discharge nozzle 176 may be positioned above wash tub proximate a rear of opening 116 defined through top panel 118. Dispensing assembly 112 may be regulated by controller 156 to discharge wash fluid 178 through discharge nozzle 176 at the desired flow rates, volumes, and/or detergent concentrations to facilitate various operating cycles, e.g., such as wash or rinse cycles.

Although water supply conduit 166, water supply source 170, discharge nozzle 176, and water control valve 172 are all described and illustrated herein in the singular form, it should be appreciated that these terms may be used herein generally to describe a supply plumbing for providing hot and/or cold water into wash chamber 110. In this regard, water supply conduit 166 may include separate conduits for receiving hot and cold water, respectively. Similarly, water supply source 170 may include both hot- and cold-water supplies regulated by dedicated valves. In addition, washing machine appliance 100 may include one or more pressure sensors (not shown) for detecting the amount of water and or clothes within wash tub 108. For example, the pressure sensor may be operably coupled to a side of tub 108 for detecting the weight of wash tub 108, which controller 156 may use to determine a volume of water in wash chamber 110 and a subwasher load weight.

After wash tub 108 is filled and the agitation phase of the wash cycle is completed, wash basket 114 can be drained, e.g., by drain pump assembly 130. Laundry articles can then be rinsed by again adding fluid to wash basket 114 depending on the specifics of the cleaning cycle selected by a user. The impeller or agitation element 132 may again provide agitation within wash basket 114. One or more spin cycles may also be used as part of the cleaning process. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle in order to wring wash fluid from the articles being washed. During a spin cycle, wash basket 114 is rotated at relatively high speeds to help wring fluid from the laundry articles through perforations 126. During or prior to the spin cycle, drain pump assembly 130 may operate to discharge wash fluid from wash tub 108, e.g., to an external drain. After articles disposed in wash basket 114 are cleaned and/or washed, the user can remove the articles from wash basket 114, e.g., by reaching into wash basket 114 through opening 116.

Referring now specifically to FIG. 3, washing machine appliance 100 may include a sensor assembly 180 that includes one or more sensors for providing useful information regarding a particular load or operating cycle of the appliance. This information may be used for improved appliance performance, as described in more detail herein. For example, sensor assembly 180 may include a turbidity sensor 182, e.g., for monitoring the contaminant level or soil level of wash fluid 178, e.g., in order to determine the cleanliness of the clothes or to determine appropriate rinse parameters.

According to the illustrated embodiment, sensor assembly 180 and turbidity sensor 182 may be mounted within sump 128 where it is capable of obtaining accurate reading of wash fluid 178 within wash tub 108. According to still other embodiments, turbidity sensor 182 may alternatively be positioned within a drain line or in drain pump assembly 130, within a recirculation line or assembly, or at any other location where it is in contact with collected wash fluid 178.

According to an example embodiment, turbidity sensor 182 may operate by using an emitter to emit a beam of light that is passed through wash fluid 178 and detecting the beam of light using a receiver. In this manner, the turbidity of wash fluid 178 may be estimated based on the distortion of the beam of light. Although turbidity sensor 182 is illustrated herein as including an emitter and receiver for generating and receiving a beam of light, it should be appreciated that this is only one exemplary embodiment. Any other suitable type or configuration of turbidity sensor may be used while remaining within the scope of the present subject matter. Other sensor configurations are possible and within the scope of the present subject matter.

In addition, sensor assembly 180 may be used to monitor the wash process using any other suitable sensors. For example, as illustrated, sensor assembly 180 may include an auxiliary sensor 184 that is positioned in sump 128 and is configured for monitoring other suitable parameters or conditions of the wash fluid 178. For example, auxiliary sensor 184 may be a conductivity sensor for measuring the electrical conductivity of the wash fluid 178. In addition, or alternatively, auxiliary sensor 184 may be a pH sensor for measuring the pH of the wash fluid 178. The conductivity and pH may be related to the conditions of the wash fluid 178 and may be used to facilitate an improved rinse cycle, as described herein with respect to the use of turbidity measurements.

Referring still to FIG. 1, a schematic diagram of an external communication system 190 will be described according to an exemplary embodiment of the present subject matter. In general, external communication system 190 is configured for permitting interaction, data transfer, and other communications between washing machine appliance 100 and one or more external devices. For example, this communication may be used to provide and receive operating parameters, user instructions or notifications, performance characteristics, user preferences, or any other suitable information for improved performance of washing machine appliance 100. In addition, it should be appreciated that external communication system 190 may be used to transfer data or other information to improve performance of one or more external devices or appliances and/or improve user interaction with such devices.

For example, external communication system 190 permits controller 156 of washing machine appliance 100 to communicate with a separate device external to washing machine appliance 100, referred to generally herein as an external device 192. As described in more detail below, these communications may be facilitated using a wired or wireless connection, such as via a network 194. In general, external device 192 may be any suitable device separate from washing machine appliance 100 that is configured to provide and/or receive communications, information, data, or commands from a user. In this regard, external device 192 may be, for example, a personal phone, a smartphone, a tablet, a laptop or personal computer, a wearable device, a smart home system, or another mobile or remote device.

In addition, a remote server 196 may be in communication with washing machine appliance 100 and/or external device 192 through network 194. In this regard, for example, remote server 196 may be a cloud-based server 196, and is thus located at a distant location, such as in a separate state, country, etc. According to an exemplary embodiment, external device 192 may communicate with a remote server 196 over network 194, such as the Internet, to transmit/receive data or information, provide user inputs, receive user notifications or instructions, interact with or control washing machine appliance 100, etc. In addition, external device 192 and remote server 196 may communicate with washing machine appliance 100 to communicate similar information.

In general, communication between washing machine appliance 100, external device 192, remote server 196, and/or other user devices or appliances may be carried using any type of wired or wireless connection and using any suitable type of communication network, non-limiting examples of which are provided below. For example, external device 192 may be in direct or indirect communication with washing machine appliance 100 through any suitable wired or wireless communication connections or interfaces, such as network 194. For example, network 194 may include one or more of a local area network (LAN), a wide area network (WAN), a personal area network (PAN), the Internet, a cellular network, any other suitable short- or long-range wireless networks, etc. In addition, communications may be transmitted using any suitable communications devices or protocols, such as via Wi-Fi®, Bluetooth®, Zigbee®, wireless radio, laser, infrared, Ethernet type devices and interfaces, etc. In addition, such communication may use a variety of communication protocols (e.g., TCP/IP, HTTP, SMTP, FTP), encodings or formats (e.g., HTML, XML), and/or protection schemes (e.g., VPN, secure HTTP, SSL).

External communication system 190 is described herein according to an exemplary embodiment of the present subject matter. However, it should be appreciated that the exemplary functions and configurations of external communication system 190 provided herein are used only as examples to facilitate description of aspects of the present subject matter. System configurations may vary, other communication devices may be used to communicate directly or indirectly with one or more associated appliances, other communication protocols and steps may be implemented, etc. These variations and modifications are contemplated as within the scope of the present subject matter.

While described in the context of a specific embodiment of vertical axis washing machine appliance 100, using the teachings disclosed herein it will be understood that vertical axis washing machine appliance 100 is provided by way of example only. Other washing machine appliances having different configurations, different appearances, and/or different features may also be utilized with the present subject matter as well, e.g., horizontal axis washing machine appliances. In addition, aspects of the present subject matter may be utilized in a combination washer/dryer appliance.

Now that the construction of washing machine appliance 100 and the configuration of controller 156 according to exemplary embodiments have been presented, an exemplary method 200 of operating a washing machine appliance will be described. Although the discussion below refers to the exemplary method 200 of operating washing machine appliance 100, one skilled in the art will appreciate that the exemplary method 200 is applicable to the operation of a variety of other washing machine appliances, such as horizontal axis washing machine appliances. In exemplary embodiments, the various method steps as disclosed herein may be performed by controller 156 or a separate, dedicated controller.

Referring now to FIG. 4, method 200 includes, at step 210, operating a water supply to dispense a target volume of wash fluid into a wash tub of a washing machine appliance. For example, using washing machine appliance 100 as an example, the wash cycle may include operating a water supply (e.g., via water control valve 172) to add wash fluid (e.g., water, detergent, and/or other additives) into wash tub 108. As used herein, the “target volume” of wash fluid may be used to refer generally to the volume of wash fluid desirable for the performance of a complete wash cycle. In this regard, for example, the target volume of wash fluid may be the maximum amount of wash fluid dispensed into wash tub 108 during the agitation phase or wash phase of an operating cycle. According to exemplary embodiments, the target volume may be set by the user, determined based on cycle parameters, or may be determined using a load sensing procedure. In addition, it should be appreciated that this target volume may be measured and represented using any suitable unit of measure, e.g., such as inches of wash fluid, total volume in gallons, etc.

Step 220 may generally include operating a motor assembly to perform an additive mixing cycle to agitate wash additive within the target volume of wash fluid. In this regard, a wash additive may be dispensed along with wash fluid 178, e.g., via a bulk reservoir 158 and aspirator assembly 162. As explained in more detail herein, it may be desirable to obtain a turbidity measurement of the wash fluid within wash tub 108 after the wash additive is added. More specifically, in order to ensure the wash additive within the target volume of wash fluid has been properly mixed or dispersed within the target volume, the additive mixing cycle may be a cursory agitation of the wash fluid prior to the agitation cycle, described in more detail below.

Step 230 may include obtaining a first turbidity measurement of the wash fluid using a turbidity sensor. For example, turbidity sensor 182 may be positioned within sump 128 of wash tub 108 and may be used to obtain a first turbidity after the additive mixing cycle has been completed. According to still other embodiments, the first turbidity may be obtained during the additive mixing cycle, may be an average of turbidity measurements obtained during an additive mixing cycle, or may be obtained in any other suitable manner.

Step 240 may generally include operating the motor assembly to perform an agitation cycle with the target volume of the wash fluid. In this regard, after obtaining the first turbidity measurement, and with the target volume of wash fluid still present within wash tub 108, motor assembly 138 may perform an agitation/wash cycle to clean the articles of clothing present within wash basket 114. It should be appreciated that the agitation cycle parameters may be determined in any suitable manner for achieving the desired cleanliness of the articles of clothing.

As explained briefly above, the additive mixing cycle is generally intended to mix, dilute, or distribute wash additive within wash fluid 178 in wash tub 108. The additive mixing cycle is not intended to agitate clothes to the extent that soils are extracted and distributed throughout wash fluid 178. Accordingly, the first turbidity measured at step 230 may be a turbidity associated with or resulting from a wash additive within the dispensed water. After the agitation cycle has been completed, step 250 may include obtaining a second turbidity of the wash fluid using the turbidity sensor. In contrast to the first turbidity, the second turbidity measurement may be affected by both wash additive within wash fluid 178 and soils that have been extracted from the clothes.

Notably, the second turbidity may be obtained after an agitation cycle that has been performed with the target volume of wash fluid. In this manner, by obtaining both the first turbidity and the second turbidity at the same wash fluid level, errors that may be introduced due to differences in detergent concentration may be reduced or eliminated altogether. For example, if the first turbidity were obtained when the wash fluid volume is lower than the wash fluid volume when the second turbidity was obtained, first turbidity may have a higher detergent concentration since the water volume is less, even though the same amount of detergent may be present. In sum, obtaining the first turbidity and the second turbidity at the same wash fluid volume may be desirable to more accurately determine the amount of turbidity associated with soils within the load of clothes. Moreover, although the turbidity measurements are described herein as being obtained when the wash fluid reaches a target volume associated with a final fill amount for a wash cycle, it should be appreciated that according to alternative embodiments, these measurements may be obtained at any other suitable wash fluid volume. For example, the turbidity reading could be taken at an initial lower fill volume (lower than the final fill volume) to increase the concentration of the soil and detergent, e.g., for the sake of improved wash performance and/or turbidity sensing resolution.

Notably, the parameters of the additive mixing cycle and the agitation cycle may vary according to exemplary embodiments of the present subject matter. For example, the additive mixing cycle may have a mixing duration and the agitation cycle may have an agitation duration. According to example embodiments, the agitation duration may be at least 2 times, at least 5 times, at least 10 times, at least 20 times, or greater, than the mixing duration. For example, according to an example embodiment, the mixing duration may be between about 3 seconds and 2 minutes, between about 5 seconds and 1 minute, or about 15 seconds. In addition, according to example embodiments, the agitation cycle and the additive mixing cycle have different agitation profiles and/or agitation intensities.

As explained above, the first turbidity and the second turbidity may be used to determine the level of turbidity associated with wash additive versus the level of turbidity associated with soils that are extracted from the load of clothes being cleaned. This information may be used to improve subsequent performance of the wash cycle, e.g., by adjusting wash cycle parameters. Specifically, step 260 may include determining a wash cycle intensity based at least in part on the first turbidity and the second turbidity.

For example, step 260 may include determining a turbidity difference between the first turbidity and the second turbidity. This turbidity difference may generally represent the amount of soils extracted from the load of clothes. This turbidity difference may generally be quantified as a mathematical difference between the measured turbidities, as a ratio of the measured turbidities, or using any other suitable mathematical quantification or relationship. Accordingly, step 260 may further include selecting the wash cycle intensity based at least in part on this turbidity difference. In general, higher soil levels (e.g., associated with a higher turbidity difference) may result in a wash cycle intensity that has increased duration, a more intense agitation profile, and increased spin speed or agitation intensity, etc. By contrast, lower soil levels (e.g., associated with a lower turbidity difference) may result in a wash cycle intensity that has decreased duration, a milder agitation profile, and lower spin speeds or agitation intensities.

Step 270 may generally include completing a wash cycle at the determined wash cycle intensity (e.g., the wash cycle intensity determined at step 260 based on the turbidity difference). Notably, the performance of such a wash cycle may be more targeted to the precise type of clothes, the size of the load, the soil level of the load of clothes, etc.

As described generally above, method 200 includes adjusting a wash cycle intensity based on the measured turbidity during various points within an operating cycle. This process may be referred to generally herein as a smart wash cycle. It should be appreciated that method 200 may further include steps for ensuring that the wash cycle intensity is adjusted based on turbidity measurements only when the user desires to perform such a smart wash cycle. Accordingly, method 200 may further include determining that a user input comprises a smart wash cycle selection prior to operating the motor assembly to perform the additive mixing cycle. According to example embodiments, this user input may be obtained through control panel 150, through external device 192 (e.g., such as a user's cell phone), or from any other suitable input source. According to still other embodiments, method 200 may include determining that the user has selected a standard wash cycle (e.g., not a smart wash cycle). According to such an embodiment, method 200 may further include performing a standard agitation/wash cycle. In this regard, the “standard agitation cycle” may refer to the factory default or programmed settings of washing machine appliance 100 during a standard operating cycle.

Referring now briefly to FIG. 5, an exemplary flow diagram of a smart wash cycle 300 that may be implemented by washing machine appliance 100 will be described according to an exemplary embodiment of the present subject matter. According to exemplary embodiments, method 300 may be similar to or interchangeable with method 200 and may be implemented by controller 156 of washing machine appliance 100. As shown, at step 302, a user may configure the wash cycle, options, and operating parameters. For example, this may include a selection between a standard wash cycle or a smart wash cycle.

Step 304 may include starting an operating cycle of a washing machine appliance and step 306 may include performing a load sensing procedure, as will be understood to one having ordinary skill in the art. Step 308 may include filling the wash tub with wash fluid. For example, step 308 may include filling the wash tub with a target volume of wash fluid for performing the operating cycle.

Step 310 may include determining whether the smart wash cycle option was selected at step 302. If the smart wash cycle was not selected or the standard wash cycle was selected, step 312 may include performing a normal agitation and wash cycle and continuing the wash cycle at step 330. By contrast, if step 310 results in a determination that the smart wash cycle option was selected, step 314 may include performing a pre-sense agitate, e.g., such as the additive mixing cycle. As explained above, this additive mixing cycle is intended to distribute or disperse wash additive without extracting a significant amount of soil from the load of clothes. Step 316 may include obtaining a first turbidity measurement using a turbidity sensor.

Step 318 may include performing a wash cycle load of clothes, e.g., by soaking the load of clothes, agitating the load of clothes, etc. Step 320 includes obtaining a second turbidity reading using the turbidity sensor. Step 322 includes determining a turbidity difference between the second turbidity (e.g., measured at step 320) and the first turbidity (e.g., measured at step 316). Step 324 may include determining wash cycle parameters based on the turbidity difference. For example, the turbidity difference may be compared to a predetermined turbidity difference to determine whether the wash cycle intensity should be increased or decreased. According to still other embodiments, step 324 may include using a lookup table or algorithm that relates a specific turbidity difference to a specific set of wash cycle parameters.

Specifically, if step 324 results in a determination that the turbidity difference is large (e.g., above a predetermined threshold), step 326 may include performing a wash cycle with a normal or increased duration and/or intensity. By contrast, if step 324 results in a determination that the turbidity difference is small (e.g., below the predetermined threshold), step 328 may include performing a wash cycle with a reduced agitation intensity or duration. The wash cycle may continue step 330.

FIGS. 4 and 5 depict steps performed in a particular order for purposes of illustration and discussion. Those of ordinary skill in the art, using the disclosures provided herein, will understand that the steps of any of the methods discussed herein can be adapted, rearranged, expanded, omitted, or modified in various ways without deviating from the scope of the present disclosure. Moreover, although aspects of method 200 and method 300 are explained using washing machine appliance 100 as an example, it should be appreciated that this method may be applied to the operation of any suitable laundry appliance, such as another washing machine appliance.

As explained above, aspects of the present subject matter are directed to a washing machine appliance that includes a turbidity sensor located in the bottom of the wash tub in contact with the wash fluid. The turbidity sensor may be used to distinguish soil level of wash fluid in the wash tub from detergent or other additives, and the washing machine may use this information to adjust various washing parameters based on the detected soil level and user inputs. The turbidity sensor may be positioned in the bottom of the wash tub in contact with the wash fluid. Prior to the start of the sensing phase, the user may provide an input to activate a smart wash algorithm (e.g., via a button on the user interface, using a voice command, via selection through a companion mobile application, etc.). After load sensing, filling, and dispensing procedures have been performed, the washing machine may perform an initial, short agitation to dissolve detergent and other additives (e.g., not agitation intended to clean clothes). After this short agitation, the washing machine may sample the turbidity of the wash fluid to establish a baseline reading (turbidity index 1). This turbidity reading may be primarily a function of detergent and other wash additives—i.e., the influence of soil level on this turbidity reading is minimal. Additional agitation and soaking of the clothes may then be performed and a second turbidity reading may be taken (turbidity index 2). This second turbidity reading may be a function of both detergent and extracted soil. A turbidity difference (delta) may be calculated between the second and first turbidity readings, effectively subtracting out the influence of detergent, such that this turbidity delta is a function of extracted soil. The remaining agitation time or other wash parameters may be adjusted based on user selections (such as cycle selected, soil level, power/care, tangle control, etc.) and the calculated turbidity delta. For example, a larger turbidity delta may result in longer agitate times as compared to a smaller turbidity delta.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

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: operate the water supply to dispense a target volume of the wash fluid into the wash tub; operate the motor assembly to perform an additive mixing cycle to agitate wash additive within the target volume of the wash fluid; obtain a first turbidity of the wash fluid using the turbidity sensor; operate the motor assembly to perform an agitation cycle with the target volume of the wash fluid; obtain a second turbidity of the wash fluid using the turbidity sensor; determine a wash cycle intensity based at least in part on the first turbidity and the second turbidity; and complete a wash cycle at the determined wash cycle intensity.

2. The washing machine appliance of claim 1, wherein the target volume is determined based at least in part using a load sensing procedure.

3. The washing machine appliance of claim 1, wherein the agitation cycle has an agitation duration and the additive mixing cycle has a mixing duration, and wherein the agitation duration is at least 10 times longer than the mixing duration.

4. The washing machine appliance of claim 1, wherein the additive mixing cycle has a mixing duration, the mixing duration being between about 5 seconds and 1 minute.

5. The washing machine appliance of claim 1, wherein the agitation cycle and the additive mixing cycle have different agitation profiles or agitation intensities.

6. The washing machine appliance of claim 1, wherein determining the wash cycle intensity based at least in part on the first turbidity and the second turbidity comprises:

determining a turbidity difference between the first turbidity and the second turbidity; and

selecting the wash cycle intensity based at least in part on the turbidity difference.

7. The washing machine appliance of claim 1, wherein the wash cycle intensity comprises:

a cycle duration of the wash cycle.

8. The washing machine appliance of claim 1, wherein the wash cycle intensity comprises:

an agitation profile or an agitation intensity.

9. The washing machine appliance of claim 1, wherein the controller is further configured to:

determine that a user input comprises a smart wash cycle selection prior to operating the motor assembly to perform the additive mixing cycle.

10. The washing machine appliance of claim 9, wherein the user input is received via a control panel of the wash machine appliance.

11. The washing machine appliance of claim 9, wherein the controller is in operative communication with a remote device over a network, and wherein the user input is received via the remote device.

12. The washing machine appliance of claim 1, wherein the controller is further configured to:

determine that a normal wash cycle has been selected; and

perform a standard agitation cycle.

13. The washing machine appliance of claim 1, wherein the turbidity sensor is positioned within the sump of the washing machine appliance.

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, a water supply for selectively adding wash fluid to the wash tub, a turbidity sensor positioned within the wash fluid, and a motor assembly mechanically coupled to the wash basket for selectively rotating the wash basket, the method comprising:

operating the water supply to dispense a target volume of the wash fluid into the wash tub;

operating the motor assembly to perform an additive mixing cycle to agitate wash additive within the target volume of the wash fluid;

obtaining a first turbidity of the wash fluid using the turbidity sensor;

operating the motor assembly to perform an agitation cycle with the target volume of the wash fluid;

obtaining a second turbidity of the wash fluid using the turbidity sensor;

determining a wash cycle intensity based at least in part on the first turbidity and the second turbidity; and

completing a wash cycle at the determined wash cycle intensity.

16. The method of claim 15, wherein the target volume is determined based at least in part using a load sensing procedure.

17. The method of claim 15, wherein the agitation cycle and the additive mixing cycle have different agitation profiles or agitation intensities.

18. The method of claim 15, wherein determining the wash cycle intensity based at least in part on the first turbidity and the second turbidity comprises:

determining a turbidity difference between the first turbidity and the second turbidity; and

selecting the wash cycle intensity based at least in part on the turbidity difference.

19. The method of claim 15, further comprising:

determining that a user input comprises a smart wash cycle selection prior to operating the motor assembly to perform the additive mixing cycle.

20. The method of claim 15, further comprising:

determining that a normal wash cycle has been selected; and

performing a standard agitation cycle.