Patent Application
20240093422
The present subject matter relates generally to dryer appliances, and more particularly to methods for performing self-clean cycles in dryer appliances.
Dryer appliances generally include a cabinet with a drum rotatably mounted therein. During operation, a motor rotates the drum, e.g., to tumble articles located within a chamber defined by the drum. Dryer appliances also generally include a heater assembly that passes heated air through the chamber in order to dry moisture-laden articles positioned therein. Typically, an air handler or blower is used to urge the flow of heated air from chamber, through a trap duct, and to the exhaust duct where it is exhausted from the dryer appliance. Dryer appliances may further include filter systems for removing foreign materials, such as lint, from passing into the exhaust conduit.
During operation of dryer appliances, dirt, grime, soil, mildew, or other undesirable build-up may be deposited on various surfaces within the appliance. For example, soil may build up within the drum, the trap duct, or within the internal air circulation ducts. As the dryer appliance is used repeatedly over multiple cycles, such residue may accumulate. If build-up is not periodically removed, bacteria can grow and develop an unpleasant odor. Notably, conventional dryer appliances do not have operating cycles intended to clean the appliance. Moreover, the temperatures required to clean the dryer appliance exceed the temperature limits to which most clothes may be exposed.
Accordingly, an improved system for maintaining the cleanliness of dryer appliances is desired. More specifically, a method of ensuring periodic cleaning of dryer appliances without the risk of damaging clothes would be particularly beneficial.
Aspects and 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 dryer appliance is provided including a cabinet, a drum rotatably mounted within the cabinet, the drum defining a chamber for receipt of clothes for drying, an air handler for selectively urging a flow of air through the chamber, a heating assembly for selectively heating the flow of air, and a controller operably coupled to the air handler and the heating assembly. The controller is configured to determine that a self-clean condition is satisfied, determine that the chamber is empty, and operate the air handler and the heating assembly to perform a self-clean cycle.
In another exemplary embodiment, a method of operating a dryer appliance is provided. The dryer appliance includes a drum rotatably mounted within a cabinet, the drum defining a chamber for receipt of clothes for drying, an air handler for selectively urging a flow of air through the chamber, and a heating assembly for selectively heating the flow of air. The method includes determining that a self-clean condition is satisfied, determining that the chamber is empty, and operating the air handler and the heating assembly to perform a self-clean cycle.
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.
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.
Repeat use of reference characters in the present specification and drawings are intended to represent the same or analogous features or elements of the present invention.
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.
Referring now to the figures,
According to exemplary embodiments, dryer appliance 10 includes cabinet 12 that is generally configured for containing and/or supporting various components of dryer appliance 10 and which may also define one or more internal chambers or compartments of dryer appliance 10. In this regard, as used herein, the terms “cabinet,” “housing,” and the like are generally intended to refer to an outer frame or support structure for dryer appliance 10, e.g., including any suitable number, type, and configuration of support structures formed from any suitable materials, such as a system of elongated support members, a plurality of interconnected panels, or some combination thereof. It should be appreciated that cabinet 12 does not necessarily require an enclosure and may simply include open structure supporting various elements of dryer appliance 10. By contrast, cabinet 12 may enclose some or all portions of an interior of cabinet 12. It should be appreciated that cabinet 12 may have any suitable size, shape, and configuration while remaining within the scope of the present subject matter.
As illustrated, dryer appliance 10 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. Cabinet 12 includes a front panel 14 and a rear panel 16 spaced apart along the transverse direction T, a pair of side panels 18 and 20 spaced apart from each other along the lateral direction L (e.g., extending between front panel 14 and rear panel 16), and a bottom panel 22 and a top panel 24 spaced apart along the vertical direction V.
Within cabinet 12 is a container or drum 26 which defines a chamber 28 for receipt of articles, e.g., clothing, linen, etc., for drying. Drum 26 extends between a front portion and a back portion, e.g., along the transverse direction T. In example embodiments, drum 26 is rotatable, e.g., about an axis that is parallel to the transverse direction T, within cabinet 12. A door 30 is rotatably mounted to cabinet 12 for providing selective access to drum 26.
An air handler 32, such as a blower or fan, may be provided to motivate an airflow (not shown) through an entrance air passage 34 and an air exhaust passage 36. Specifically, air handler 32 may include a motor 38 which may be in mechanical communication with a blower fan 40, such that motor 38 rotates blower fan 40. Air handler 32 is configured for drawing air through chamber 28 of drum 26, e.g., in order to dry articles located therein, as discussed in greater detail below. In alternative example embodiments, dryer appliance 10 may include an additional motor (not shown) for rotating fan 40 of air handler 32 independently of drum 26.
Drum 26 may be configured to receive heated air that has been heated by a heating assembly 50, e.g., in order to dry damp articles disposed within chamber 28 of drum 26. Heating assembly 50 includes a heater 52 that is in thermal communication with chamber 28. For instance, heater 52 may include one or more electrical resistance heating elements or gas burners, for heating air being flowed to chamber 28. As discussed above, during operation of dryer appliance 10, motor 38 rotates fan 40 of air handler 32 such that air handler 32 draws air through chamber 28 of drum 26. In particular, ambient air enters an air entrance passage defined by heating assembly 50 via an entrance 54 due to air handler 32 urging such ambient air into entrance 54. Such ambient air is heated within heating assembly 50 and exits heating assembly 50 as heated air. Air handler 32 draws such heated air through an air entrance passage 34, including inlet duct 56, to drum 26. The heated air enters drum 26 through an outlet 58 of inlet duct 56 positioned at a rear wall of drum 26.
Within chamber 28, the heated air can remove moisture, e.g., from damp articles disposed within chamber 28. This internal air flows in turn from chamber 28 through an outlet assembly positioned within cabinet 12. The outlet assembly generally defines an air exhaust passage 36 and includes a trap duct 60, air handler 32, and an exhaust conduit 62. Exhaust conduit 62 is in fluid communication with trap duct 60 via air handler 32. More specifically, exhaust conduit 62 extends between an exhaust inlet 64 and an exhaust outlet 66. According to the illustrated embodiment, exhaust inlet 64 is positioned downstream of and fluidly coupled to air handler 32, and exhaust outlet 66 is defined in rear panel 16 of cabinet 12. During a dry cycle, internal air flows from chamber 28 through trap duct 60 to air handler 32, e.g., as an outlet flow portion of airflow. As shown, air further flows through air handler 32 and to exhaust conduit 62.
The internal air is exhausted from dryer appliance 10 via exhaust conduit 62. In some embodiments, an external duct (not shown) is provided in fluid communication with exhaust conduit 62. For instance, the external duct may be attached (e.g., directly or indirectly attached) to cabinet 12 at rear panel 16. Any suitable connector (e.g., collar, clamp, etc.) may join the external duct to exhaust conduit 62. In residential environments, the external duct may be in fluid communication with an outdoor environment (e.g., outside of a home or building in which dryer appliance 10 is installed). During a dry cycle, internal air may thus flow from exhaust conduit 62 and through the external duct before being exhausted to the outdoor environment.
In exemplary embodiments, trap duct 60 may include a filter portion 68 which includes a screen filter or other suitable device for removing lint and other particulates as internal air is drawn out of chamber 28. The internal air is drawn through filter portion 68 by air handler 32 before being passed through exhaust conduit 62. After the clothing articles have been dried (or a drying cycle is otherwise completed), the clothing articles are removed from drum 26, e.g., by accessing chamber 28 by opening door 30. The filter portion 68 may further be removable such that a user may collect and dispose of collected lint between drying cycles.
In addition, as described in more detail below, it may be desirable to monitor a temperature of a flow of air passing through dryer appliance 10. Accordingly, dryer appliance 10 may include one or more temperature sensors positioned within the flow path for obtaining air temperature measurements. For example, according to the illustrated embodiment, dryer appliance 10 includes an outlet thermistor 70 that is positioned within trap duct 60 for measuring an air temperature of the flow of air passing through chamber 28. Outlet thermistor 70 may be used to provide feedback to an appliance controller (e.g., controller 76) to facilitate proper regulation of heating assembly 50 to obtain desired temperatures within dryer appliance 10.
Although outlet thermistor 70 is described as being used for measuring air temperatures according to example embodiments, it should be appreciated that any suitable number and type of temperature sensors may be used. In this regard, “temperature sensor” or the equivalent is intended to refer to any suitable type of temperature measuring system or device positioned at any suitable location for measuring the desired temperature. Thus, for example, the temperature sensor may each be any suitable type of temperature sensor, such as a thermistor, a thermocouple, a resistance temperature detector, a semiconductor-based integrated circuit temperature sensor, etc.
In addition, the temperature sensor may be positioned at any suitable location and may output a signal, such as a voltage, to a controller that is proportional to and/or indicative of the temperature being measured. Although exemplary positioning of temperature sensors is described herein, it should be appreciated that dryer appliance 10 may include any other suitable number, type, and position of temperature, humidity, and/or other sensors according to alternative embodiments. For example, one or more temperature sensors may be positioned in inlet duct 56, within air entrance passage 34, within air exhaust passage 36, etc.
One or more selector inputs 72, such as knobs, buttons, touchscreen interfaces, etc., may be provided on a user interface panel 74 and may be in communication with a processing device or controller 76. Signals generated in controller 76 operate motor 38, heating assembly 50, and other system components in response to the position of selector inputs 72. Additionally, a display 78, such as an indicator light or a screen, may be provided on cabinet user interface panel 74. Display 78 may be in communication with controller 76 and may display information in response to signals from controller 76.
As used herein, “processing device” or “controller” may refer to one or more microprocessors or semiconductor devices and is not restricted necessarily to a single element. The processing device can be programmed to operate dryer appliance 10. The processing device may include, or be associated with, one or more memory elements (e.g., non-transitory storage media). In some such embodiments, the memory elements include electrically erasable, programmable read only memory (EEPROM). Generally, the memory elements can store information accessible processing device, including instructions that can be executed by processing device. Optionally, the instructions can be software or any set of instructions and/or data that when executed by the processing device, cause the processing device to perform operations. For certain embodiments, the instructions include a software package configured to operate appliance 10 and execute certain cycles or operating modes.
In some embodiments, dryer appliance 10 also includes one or more sensors that may be used to facilitate improved operation of dryer appliance. For example, dryer appliance 10 may include one or more temperature sensors which are generally operable to measure internal temperatures in dryer appliance 10 and/or one or more airflow sensors which are generally operable to detect the velocity of air (e.g., as an air flow rate in meters per second, or as a volumetric velocity in cubic meters per second) as it flows through the appliance 10. In some embodiments, controller 76 is configured to vary operation of heating assembly 50 based on one or more temperatures detected by the temperature sensors or air flow measurements from the airflow sensors.
Referring still to
External communication system 90 permits controller 76 of dryer appliance 10 to communicate with external devices either directly or through a network 92. For example, a consumer may use a consumer device 94 to communicate directly with dryer appliance 10. For example, consumer devices 94 may be in direct or indirect communication with dryer appliance 10, e.g., directly through a local area network (LAN), Wi-Fi, Bluetooth, Zigbee, etc. or indirectly through network 92. In general, consumer device 94 may be any suitable device for providing and/or receiving communications or commands from a user. In this regard, consumer device 94 may include, for example, a personal phone, a tablet, a laptop computer, or another mobile device.
In addition, a remote server 96 may be in communication with dryer appliance 10 and/or consumer device 94 through network 92. In this regard, for example, remote server 96 may be a cloud-based server 96, and is thus located at a distant location, such as in a separate state, country, etc. In general, communication between the remote server 96 and the client devices may be carried via a network interface using any type of wireless connection, using 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).
In general, network 92 can be any type of communication network. For example, network 92 can include one or more of a wireless network, a wired network, a personal area network, a local area network, a wide area network, the internet, a cellular network, etc. According to an exemplary embodiment, consumer device 94 may communicate with a remote server 96 over network 92, such as the internet, to provide user inputs, transfer operating parameters or performance characteristics, receive user notifications or instructions, etc. In addition, consumer device 94 and remote server 96 may communicate with dryer appliance 10 to communicate similar information.
External communication system 90 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 90 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 laundry 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.
Referring again to
Although an exemplary camera assembly 100 is illustrated and described herein, it should be appreciated that according to alternative embodiments, dryer appliance 10 may include any other camera or system of imaging devices for obtaining images of chamber 28 or clothes located therein. It should be appreciated that camera assembly 100 may include any suitable number, type, size, and configuration of camera(s) 102 for obtaining images of chamber 28. In general, camera 102 may include a lens that is constructed from a clear hydrophobic material or which may otherwise be positioned behind a hydrophobic clear lens. So positioned, camera assembly 100 may obtain one or more images or videos of chamber 28, as described in more detail below. Dryer appliance 10 may further include a tub light that is positioned within cabinet 12 or chamber 28 for selectively illuminating chamber when images are taken.
Now that the construction of dryer appliance 10 and the configuration of controller 76 according to exemplary embodiments have been presented, an exemplary method 200 of operating a dryer appliance will be described. Although the discussion below refers to the exemplary method 200 of operating dryer appliance 10, one skilled in the art will appreciate that the exemplary method 200 is applicable to the operation of a variety of other appliances where it is desirable to perform a self-clean cycle. For example, although aspects of the present subject matter are illustrated as being implemented by a vented dryer, it should be appreciated that the present subject matter is equally applicable to non-vented dryers, condenser dryers, heat pump dryers, and/or combination washer/dryer appliances. Indeed, the present subject matter may be used to clean all portions of air circulation systems in each of these appliances. In exemplary embodiments, the various method steps as disclosed herein may be performed by controller 76 or a separate, dedicated controller.
Referring now to
In general, determining that the self-clean condition exists or is satisfied may include detecting the occurrence of one or more events or conditions within or related to dryer appliance 10. For example, determining that the self-clean condition is satisfied may include determining that a predetermined amount of time or a predetermined number of cycles has passed since performing a prior self-clean cycle. In this regard, appliance controller 76 may maintain a record or self-cleaning log may use historical cleaning schedules to intelligently determine when a new cleaning cycle is desirable. The number of cycles or the amount of time that has passed since the prior cleaning cycle that is sufficient to trigger the self-cleaning condition may be set by the manufacturer, programmed by the user, or determined in any other suitable manner. In addition, according to alternative embodiments, determining that the self-clean condition is satisfied may include receiving a user input to perform the self-clean cycle, e.g., through selector inputs 72 or remote device 94. In this regard, if a user detects foul smells or otherwise wishes to run a self-cleaning cycle, they may initiate such a cycle directly.
Notably, a self-clean cycle often includes operating the dryer appliance 10 at temperature levels and under operating parameters that are not intended for use with any clothes or during any drying process. Indeed, the air temperatures achieved during the self-clean cycle may exceed acceptable temperature ranges for some or all clothes and exposure to such temperatures would damage clothes. Accordingly, it may be desirable to ensure that no clothes are present within chamber 28 prior to performing a self-cleaning cycle. As such, step 220 may generally include determining that a chamber of the dryer appliance is empty. This determination may be made in a variety of ways, examples of which are provided below.
According to an example embodiment, dryer appliance 10 may use one or more images of chamber 28 to determine that chamber 28 is empty and contains no clothes that might be damaged during a self-clean cycle. For example, the step of determining that the chamber is empty may include obtaining an image of the chamber, e.g., using a camera 102 of camera assembly 100. In addition, this step may include analyzing the image using an image recognition process to determine that the chamber is empty.
According to alternative embodiments, the one or more images of chamber 28 may be obtained by a remote source. For example, controller 76 of dryer appliance 10 may be in operative communication with a remote device 94, such as a user's cell phone. Upon determining that a self-clean condition exists, controller 76 may request the user to obtain an image of chamber 28 using remote device 94. This image may be transmitted from remote device 94 to controller 76 where it may be analyzed using an image recognition process to determine that the chamber is empty.
As used herein, the terms “image analysis,” “image recognition,” and the like may be used generally to refer to any suitable method of observation, analysis, image decomposition, feature extraction, image classification, etc. of one or more images, videos, or other visual representations of an object. As explained in more detail below, this image analysis may include the implementation of image processing techniques, image recognition techniques, or any suitable combination thereof. In this regard, the image analysis may use any suitable image analysis software or algorithm to constantly or periodically monitor chamber 28. It should be appreciated that this image analysis or processing may be performed locally (e.g., by controller 76) or remotely (e.g., by offloading image data to a remote server or network).
Specifically, the analysis of the one or more images may include implementation an image processing algorithm. As used herein, the terms “image processing” and the like are generally intended to refer to any suitable methods or algorithms for analyzing images that do not rely on artificial intelligence or machine learning techniques (e.g., in contrast to the machine learning image recognition processes described below). For example, the image processing algorithm may rely on image differentiation, e.g., such as a pixel-by-pixel comparison of two sequential images. This comparison may help identify substantial differences between the sequentially obtained images, e.g., to identify movement, the presence of a particular object, the existence of a certain condition, etc. For example, one or more reference images may be obtained when a particular condition exists, and these references images may be stored for future comparison with images obtained during appliance operation. Similarities and/or differences between the reference image and the obtained image may be used to extract useful information for improving appliance performance.
According to exemplary embodiments, image processing may include blur detection algorithms that are generally intended to compute, measure, or otherwise determine the amount of blur in an image. For example, these blur detection algorithms may rely on focus measure operators, the Fast Fourier Transform along with examination of the frequency distributions, determining the variance of a Laplacian operator, or any other methods of blur detection known by those having ordinary skill in the art. In addition, or alternatively, the image processing algorithms may use other suitable techniques for recognizing or identifying items or objects, such as edge matching or detection, divide-and-conquer searching, greyscale matching, histograms of receptive field responses, or another suitable routine (e.g., executed at the controller 76 based on one or more captured images from one or more cameras). Other image processing techniques are possible and within the scope of the present subject matter. The processing algorithm may further include measures for isolating or eliminating noise in the image comparison, e.g., due to image resolution, data transmission errors, inconsistent lighting, or other imaging errors. By eliminating such noise, the image processing algorithms may improve accurate object detection, avoid erroneous object detection, and isolate the important object, region, or pattern within an image.
In addition to the image processing techniques described above, the image analysis may include utilizing artificial intelligence (“AI”), such as a machine learning image recognition process, a neural network classification module, any other suitable artificial intelligence (AI) technique, and/or any other suitable image analysis techniques, examples of which will be described in more detail below. Moreover, each of the exemplary image analysis or evaluation processes described below may be used independently, collectively, or interchangeably to extract detailed information regarding the images being analyzed to facilitate performance of one or more methods described herein or to otherwise improve appliance operation. According to exemplary embodiments, any suitable number and combination of image processing, image recognition, or other image analysis techniques may be used to obtain an accurate analysis of the obtained images.
In this regard, the image recognition process may use any suitable artificial intelligence technique, for example, any suitable machine learning technique, or for example, any suitable deep learning technique. According to an exemplary embodiment, the image recognition process may include the implementation of a form of image recognition called region based convolutional neural network (“R-CNN”) image recognition. Generally speaking, R-CNN may include taking an input image and extracting region proposals that include a potential object or region of an image. In this regard, a “region proposal” may be one or more regions in an image that could belong to a particular object or may include adjacent regions that share common pixel characteristics. A convolutional neural network is then used to compute features from the region proposals and the extracted features will then be used to determine a classification for each particular region.
According to still other embodiments, an image segmentation process may be used along with the R-CNN image recognition. In general, image segmentation creates a pixel-based mask for each object in an image and provides a more detailed or granular understanding of the various objects within a given image. In this regard, instead of processing an entire image—i.e., a large collection of pixels, many of which might not contain useful information—image segmentation may involve dividing an image into segments (e.g., into groups of pixels containing similar attributes) that may be analyzed independently or in parallel to obtain a more detailed representation of the object or objects in an image. This may be referred to herein as “mask R-CNN” and the like, as opposed to a regular R-CNN architecture. For example, mask R-CNN may be based on fast R-CNN which is slightly different than R-CNN. For example, R-CNN first applies a convolutional neural network (“CNN”) and then allocates it to zone recommendations on the covn5 property map instead of the initially split into zone recommendations. In addition, according to exemplary embodiments, standard CNN may be used to obtain, identify, or detect any other qualitative or quantitative data related to one or more objects or regions within the one or more images. In addition, a K-means algorithm may be used.
According to still other embodiments, the image recognition process may use any other suitable neural network process while remaining within the scope of the present subject matter. For example, the step of analyzing the one or more images may include using a deep belief network (“DBN”) image recognition process. A DBN image recognition process may generally include stacking many individual unsupervised networks that use each network's hidden layer as the input for the next layer. According to still other embodiments, the step of analyzing one or more images may include the implementation of a deep neural network (“DNN”) image recognition process, which generally includes the use of a neural network (computing systems inspired by the biological neural networks) with multiple layers between input and output. Other suitable image recognition processes, neural network processes, artificial intelligence analysis techniques, and combinations of the above described or other known methods may be used while remaining within the scope of the present subject matter.
In addition, it should be appreciated that various transfer techniques may be used but use of such techniques is not required. If using transfer techniques learning, a neural network architecture may be pretrained such as VGG16/VGG19/ResNet50 with a public dataset then the last layer may be retrained with an appliance specific dataset. In addition, or alternatively, the image recognition process may include detection of certain conditions based on comparison of initial conditions, may rely on image subtraction techniques, image stacking techniques, image concatenation, etc. For example, the subtracted image may be used to train a neural network with multiple classes for future comparison and image classification.
It should be appreciated that the machine learning image recognition models may be actively trained by the appliance with new images, may be supplied with training data from the manufacturer or from another remote source, or may be trained in any other suitable manner. For example, according to exemplary embodiments, this image recognition process relies at least in part on a neural network trained with a plurality of images of the appliance in different configurations, experiencing different conditions, or being interacted with in different manners. This training data may be stored locally or remotely and may be communicated to a remote server for training other appliances and models. According to exemplary embodiments, it should be appreciated that the machine learning models may include supervised and/or unsupervised models and methods. In this regard, for example, supervised machine learning methods (e.g., such as targeted machine learning) may help identify problems, anomalies, or other occurrences which have been identified and trained into the model. By contrast, unsupervised machine learning methods may be used to detect clusters of potential failures, similarities among data, event patterns, abnormal concentrations of a phenomenon, etc.
It should be appreciated that image processing and machine learning image recognition processes may be used together to facilitate improved image analysis, object detection, or to extract other useful qualitative or quantitative data or information from the one or more images that may be used to improve the operation or performance of the appliance. Indeed, the methods described herein may use any or all of these techniques interchangeably to improve image analysis process and facilitate improved appliance performance and consumer satisfaction. The image processing algorithms and machine learning image recognition processes described herein are only exemplary and are not intended to limit the scope of the present subject matter in any manner.
According to still other embodiments, step 220 of determining that a chamber of the dryer appliance is empty may use one or more weight sensors to determine that there is nothing present within the drum. In this regard, for example, dryer appliance 10 may include a weight sensor 104 that is mechanically coupled to drum 26 for measuring the drum weight. As such, step 220 may include obtaining a drum weight using weight sensor 104 and determining that the drum weight exceeds a predetermined weight. For example, the predetermined weight may be associated with an empty drum. Accordingly, if the measured weight is higher than the empty drum weight, this may be indicative of clothes being present within chamber 28. According to still other example embodiments, moisture sensing rods and/or the inlet/outlet thermistor temperatures (or a rate of change of these temperatures) may be used to determine whether drum 26 is empty.
After the self-clean condition is satisfied in the drum is empty, it may be safe to run a self-clean cycle. However, it is also possible that a consumer will attempt to access chamber 28 after the initiation of the self-clean cycle, e.g., to initiate a new drying cycle. In order to prevent potentially harmful situations related to the high temperatures associated with a self-clean cycle, it may be desirable to prevent access to dryer appliance 10 during the performance of such a cycle. Accordingly, dryer appliance 10 may further include a door lock 106 that is mechanically coupled to the door 30 and may selectively lock door 30 in the closed position. Step 230 of method 200 may generally include locking a door of the dryer appliance in a closed position using the door lock.
Step 240 may generally include performing a self-cleaning cycle of dryer appliance 10. In this regard, when the self-clean condition exists (e.g., determined at step 210), the chamber is determined to be empty (e.g., determined at step 220), and the door is locked (e.g., at step 230), step 240 may include the safe initiation of the self-clean cycle. Specifically, step 240 may include operating the air handler and operating a heating assembly of the dryer appliance to perform a self-cleaning cycle. For example, the self-clean cycle may include maintaining a flow of air throughout dryer appliance 10 at a self-cleaning temperature for a predetermined amount of time. Although exemplary self-clean cycle parameters are provided below, it should be appreciated that these parameters may vary while remaining within the scope of the present subject matter.
In general, the self-clean cycle may include circulating a flow of air using air handler 32 while operating heating assembly 50 and heating the flow of air to a predetermined self-cleaning temperature. As explained above, the self-cleaning temperature is typically well above the temperatures associated with normal drying cycles. For example, conventional dryers have a maximum temperature limit for operating cycles of at or below 130° F. By contrast, a self-cleaning temperature in accordance with the present subject matter may include an air temperature that is greater than or equal to 160° F., greater than or equal to 170° F., greater than or equal to 180° F., or greater.
In addition, it may be desirable to maintain the flow of air at the self-clean temperature for a predetermined amount of time, referred to herein as the predetermined self-cleaning time. In this regard, by maintaining the air temperature at the self-clean temperature for the predetermined amount of time, most or all of the build up within dryer appliance 10 may be neutralized or eliminated. For example, the self-cleaning time may be greater than or equal to 5 minutes, greater than or equal to 10 minutes, greater than or equal to 20 minutes, greater than or equal to 30 minutes, greater than or equal to 1 hour, or greater. Other variations in the self-clean cycle temperatures alterations may be used while remaining within the scope of the present subject matter.
Notably, according to an exemplary embodiment, it may be desirable to ensure that the surfaces within dryer appliance 10 have reached a sufficiently high temperature to neutralize or eliminate any build up within the airflow passages. Accordingly, method 200 may further include determining that the self-cleaning temperature has been reached by monitoring a rate of temperature change of the flow of air after the heating assembly has been turned off. In this regard, if a hot flow of air has only been passing through dryer appliance 10 for a short amount of time, turning off the heating assembly may result in a fast or almost immediate decrease in the airflow temperature (e.g., as appliance surface temperatures may be insufficient to provide residual heat into the airflow). By contrast, if the dryer appliance 10 has been fully heat soaked by a long self-clean cycle, turning off the heating assembly may result in a slower decrease in the temperature of the airflow (e.g., as the component surfaces provide heat to the airflow circulating across them). Thus, monitoring this rate of temperature difference after the heating assembly is turned off may be used to assess the effectiveness of a self-clean cycle.
According to example embodiments the present subject matter, dryer appliance 10 may include additional features for improving the performance of a self-clean cycle. In this regard, for example, dryer appliance 10 may include features for introducing liquid or steam into the airflow path during the self-clean cycle. In this regard, dryer appliance 10 may include a steam supply nozzle 110 for selectively spraying liquid 112 into the flow of air. In addition, method 200 may further include operating the steam supply nozzle to inject the liquid during the self-clean cycle. For example, steam supply nozzle 110 may project a fine liquid mist or a stream of liquid 112. In this regard, it may be desirable to ensure that the component surfaces within dryer appliance 10 are hot enough to evaporate or steam any liquid that is dispensed on such components. In this manner, excessive steam or moisture within the air may help breakdown build up and facilitate improved cleaning cycle. In addition, it should be appreciated that the self-clean cycle may include two or more stages. For example, the first stage may include a steam injection stage during which steam is supplied into the airflow to help clean internal surfaces of dryer appliance 10 and the second stage may include a dry air stage where the steam is no longer provided and fresh air flows through to sanitize and dry surfaces. It should be appreciated that other variations and modifications to the self-clean cycle may be made while remaining within the scope of the present subject matter.
As explained above, aspects of the present subject matter are directed to a dryer appliance and methods of performing a self-cleaning cycle using the dryer appliance. In specific, a self-cleaning cycle may be used to blow air at temperatures hotter than would normally be allowed when garments are inside the dryer. Prior to application of such hot temperatures, the dryer appliance may verify that no garments remain in the dryer drum before running the self-cleaning cycle, e.g., by using an appliance-mounted camera or smartphone camera. The dryer appliance may include a door lock, similar to those used in kitchen stoves, to prevent the unit from being opened during the self-cleaning cycle.
The cycle can continue for a predetermined time at the “self-cleaning” set point which may be determined based on the outlet thermistor temperature. The outlet thermistor provides a good indication of drum temperature, showing all relevant dryer components are up to temperature. According to example embodiments, this self-cleaning cycle may use a water/steam jet to “steam clean” the inner drum of the dryer at extremely high temperatures. Likewise, the outlet thermistor temperature can be used to determine when the drum is hot enough to inject water/steam. Even if a mist of cold water is sprayed into the drum, the drum should be hot enough to generate steam quickly. It may also be beneficial to reduce airflow through the drum/dryer to allow the unit to reach higher cleaning temperatures and feedback control is using an inlet thermistor can be used to ensure the proper minimum airflow is used.
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.
