Dishwashers are used in many single-family and multi-family residential applications to clean dishes, silverware, cutlery, cups, glasses, pots, pans, etc. (collectively referred to herein as “utensils”). Many dishwashers rely primarily on rotatable spray arms that are disposed at the bottom and/or top of a tub and/or are mounted to a rack that holds utensils. A spray arm is coupled to a source of wash fluid and includes multiple apertures for spraying wash fluid onto utensils, and generally rotates about a central hub such that each aperture follows a circular path throughout the rotation of the spray arm. The apertures may also be angled such that force of the wash fluid exiting the spray arm causes the spray arm to rotate about the central hub.
While traditional spray arm systems are simple and mostly effective, they have the shortcoming of that they must spread the wash fluid over all areas equally to achieve a satisfactory result. In doing so, resources such as time, energy and water are generally wasted because wash fluid cannot be focused precisely where it is needed. Moreover, because spray arms follow a generally circular path, the corners of a tub may not be covered as thoroughly, leading to lower cleaning performance for utensils located in the corners of a rack. In addition, in some instances the spray jets of a spray arm may be directed to the sides of a wash tub during at least portions of the rotation, leading to unneeded noise during a wash cycle.
Various efforts have been made to attempt to customize wash cycles to improve efficiency as well as wash performance, e.g., using cameras and other types of image sensors to sense the contents of a dishwasher, as well as utilizing spray arms that provide more focused washing in particular areas of a dishwasher. Nonetheless, a significant need still exists in the art for greater efficiency and efficacy in dishwasher performance.
The herein-described embodiments address these and other problems associated with the art by providing a cam-based position sensor that is configured to sense multiple rotational positions for a discretely directable tubular spray element driven by a tubular spray element drive.
Therefore, consistent with one aspect of the invention, a dishwasher may include a wash tub, a fluid supply, a tubular spray element disposed in the wash tub and being rotatable about a longitudinal axis thereof, the tubular spray element including one or more apertures extending through an exterior surface thereof, and the tubular spray element in fluid communication with the fluid supply to direct fluid from the fluid supply into the wash tub through the one or more apertures, a tubular spray element drive coupled to the tubular spray element and configured to rotate the tubular spray element between a plurality of rotational positions about the longitudinal axis thereof, a cam-based position sensor configured to sense multiple rotational positions among the plurality of rotational positions, the cam-based position sensor including one or more cam detectors and a plurality of cam lobes operably coupled to the tubular spray element to rotate therewith, and a controller coupled to the tubular spray element drive and the cam-based position sensor, where the controller is configured to control the tubular spray element drive to discretely direct the tubular spray element to one or more rotational positions using the cam-based position sensor.
In addition, in some embodiments, first and second cam lobes among the plurality of cam lobes rotate about a common axis and in a common plane, and the one or more cam detectors includes at least one cam detector positioned to detect the first and second cam lobes rotating in the common plane. Also, in some embodiments, the one or more cam detectors includes first and second cam detectors positioned at respective first and second rotational positions about the common axis of the first and second cam lobes. Moreover, in some embodiments, first and second cam lobes among the plurality of cam lobes rotate about a common axis and in respective first and second planes, and the one or more cam detectors includes at least first and second cam detectors respectively positioned to detect the first and second cam lobes rotating in the respective first and second planes. Further, in some embodiments, the plurality of cam lobes are configured to rotate about an axis of rotation that is coincident with the longitudinal axis of the tubular spray element. Also, in some embodiments, the plurality of cam lobes are configured to rotate about an axis of rotation that is parallel to and offset from the longitudinal axis of the tubular spray element.
Further, in some embodiments, the tubular spray element drive includes a motor that drives a drive shaft and a plurality of gears that operably couple the drives haft to the tubular spray element, and the axis of rotation about which the plurality of cam lobes rotate is coincident with an axis of rotation of the drive shaft. In some embodiments, the at least one cam detector includes a microswitch positioned within a path of travel of at least one of the plurality of cam lobes such that rotation of the tubular spray element to a predetermined rotational position causes the at least one of the plurality of cam lobes to physically engage the microswitch.
Also, in some embodiments, at least one of the plurality of cam lobes includes a magnet, and the at least one cam detector includes a magnetic sensor positioned such that rotation of the tubular spray element to a predetermined rotational position causes the at least one of the plurality of cam lobes to position the magnet adjacent the magnetic sensor. In some embodiments, at least one of the plurality of cam lobes includes an electrical conductor, and the at least one cam detector includes at least one electrical contact positioned such that rotation of the tubular spray element to a predetermined rotational position causes the electrical conductor to engage the at least one electrical contact.
Further, in some embodiments, the multiple rotational positions sensed by the cam-based position sensor include a home rotational position of the tubular spray element. In some embodiments, the multiple rotational positions sensed by the cam-based position sensor include first and second rotational positions respectively associated with first and second zones of a utensil rack.
Some embodiments may also include a valve configured to regulate fluid flow to the tubular spray element, the valve being actuated in response to rotation of the tubular spray element and having an off position that closes the valve when the tubular spray element is rotated to a predetermined rotational position, and the multiple rotational positions sensed by the cam-based position sensor include the predetermined rotational position at which the valve is rotated to the off position. Further, in some embodiments, the multiple rotational positions sensed by the cam-based position sensor include at least one limit rotational position that restricts a range of rotation of the tubular spray element.
Also, in some embodiments, the tubular spray element is mounted to a wall of the wash tub. In addition, some embodiments may also include a rotatable docking port coupled to a wall of the wash tub and in fluid communication with the fluid supply, and a rack supported in the wash tub and movable between loading and washing positions, where the tubular spray element is supported by the rack for movement with the rack and configured to receive fluid from the rotatable docking port when the rack is in the washing position.
In some embodiments, the controller is configured to control the tubular spray element drive to discretely direct the tubular spray element to one or more rotational positions using the cam-based position sensor by driving rotation of the tubular spray element for a predetermined time corresponding to a desired rotational displacement after sensing one of the multiple rotational positions with the cam-based position sensor. In addition, in some embodiments, the controller is configured to determine the predetermined time corresponding to the desired rotational displacement using a rotational rate of the tubular spray element drive, and the controller is configured to determine the rotational rate of the tubular spray element drive by performing a calibration operation. Also, in some embodiments, the controller is configured to perform the calibration operation by rotating the tubular spray element to a first rotational position among the multiple rotational positions sensed by the cam-based position sensor, rotating the tubular spray element to a second rotational position among the multiple rotational positions sensed by the cam-based position sensor, determining a time associated with rotating the tubular spray element from the first rotational position to the second rotational position, and determining the rotational rate of the tubular spray element based upon the determined time and a rotational offset between the first and second rotational positions.
Consistent with another aspect of the invention, a method may be performed for calibrating a tubular spray element drive of a dishwasher, where the tubular spray element drive is configured to rotate a tubular spray element disposed in a wash tub of the dishwasher and being rotatable about a longitudinal axis thereof, where the tubular spray element includes one or more apertures extending through an exterior surface thereof, and where the tubular spray element is in fluid communication with a fluid supply to direct fluid from the fluid supply into the wash tub through the one or more apertures. The method includes rotating the tubular spray element with the tubular spray element drive to a first rotational position sensed by a cam-based position sensor that is configured to sense multiple rotational positions among a plurality of rotational positions about which the tubular spray element drive is configured to rotate the tubular spray element, the cam-based position sensor including one or more cam detectors and a plurality of cam lobes operably coupled to the tubular spray element to rotate therewith, rotating the tubular spray element with the tubular spray element drive to a second rotational position among the multiple rotational positions sensed by the cam-based position sensor, determining a time associated with rotating the tubular spray element from the first rotational position to the second rotational position, and determining a rotational rate of the tubular spray element based upon the determined time and a rotational offset between the first and second rotational positions.
These and other advantages and features, which characterize the invention, are set forth in the claims annexed hereto and forming a further part hereof. However, for a better understanding of the invention, and of the advantages and objectives attained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which there is described example embodiments of the invention. This summary is merely provided to introduce a selection of concepts that are further described below in the detailed description, and is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In various embodiments discussed hereinafter, a cam-based position sensor is used in connection with a discretely directable tubular spray element to sense multiple rotational positions for the tubular spray element.
In addition, in various embodiments discussed hereinafter, an imaging system may be used within a dishwasher to perform various operations within the dishwasher. An imaging system, in this regard, may be considered to include one or more cameras or other imaging devices capable of capturing images within a dishwasher. The images may be captured in the visible spectrum in some embodiments, while in other embodiments other spectrums may be captured, e.g., the infrared spectrum. Imaging devices may be positioned in fixed locations within a dishwasher in some embodiments, and in other embodiments may be positioned on movable and/or controllable components, as will become more apparent below. In addition, captured images may be analyzed locally within a dishwasher in some embodiments, while in other embodiments captured images may be analyzed remotely, e.g., using a cloud-based service. Furthermore, imaging devices may generate two dimensional images in some embodiments, while in other embodiments captured images may be three dimensional in nature, e.g., to enable surface models to be generated for structures within a dishwasher, including both components of the dishwasher and articles placed in the dishwasher to be washed. Images may also be combined in some embodiments, and in some embodiments multiple images may be combined into videos clips prior to analysis.
In some embodiments consistent with the invention, and as will become more apparent below, an imaging system may be utilized in connection with one or more controllable sprayers. A controllable sprayer, in this regard, may refer to a component capable of selectively generating a spray of fluid towards any of a plurality of particular spots, locations, or regions of a dishwasher, such that through control of the sprayer, fluid may be selectively sprayed into different spots, locations or regions as desired. When paired with an imaging system consistent with the invention, therefore, a controller of a dishwasher may be capable of controlling one or more controllable sprayers to direct fluid into specific spots, locations or regions based upon images captured by an imaging system.
In some instances, a controllable sprayer may be implemented using multiple nozzles directed at different spots, locations or regions and selectively switchable between active and inactive states. In other embodiments, however, a controllable sprayer may be a controllably-movable sprayer that is capable of being moved, e.g., through rotation, translation or a combination thereof, to direct a spray of fluid to different spots, locations or regions. Moreover, while some controllably-movable sprayers may include designs such as gantry-mounted wash arms or other sprayers, controllably-rotatable wash arms, motorized sprayers, and the like, in some embodiments, a controllably-movable sprayer may be configured as a tubular spray element that is rotatable about a longitudinal axis and discretely directed through each of a plurality of rotational positions about the longitudinal axis by a tubular spray element drive to spray a fluid such as a wash liquid and/or pressurized air in a controlled direction generally transverse from the longitudinal axis about which the tubular spray element rotates.
A tubular spray element, in this regard, may be considered to include an elongated body, which may be generally cylindrical in some embodiments but may also have other cross-sectional profiles in other embodiments, and which has one or more apertures disposed on an exterior surface thereof and in fluid communication with a fluid supply, e.g., through one or more internal passageways defined therein. A tubular spray element also has a longitudinal axis generally defined along its longest dimension and about which the tubular spray element rotates, and furthermore, a tubular spray element drive is coupled to the tubular spray element to discretely direct the tubular spray element to multiple rotational positions about the longitudinal axis. In addition, when a tubular spray element is mounted on a rack and configured to selectively engage with a dock based upon the position of the rack, this longitudinal axis may also be considered to be an axis of insertion. A tubular spray element may also have a cross-sectional profile that varies along the longitudinal axis, so it will be appreciated that a tubular spray element need not have a circular cross-sectional profile along its length as is illustrated in a number embodiments herein. In addition, the one or more apertures on the exterior surface of a tubular spray element may be arranged into nozzles in some embodiments, and may be fixed or movable (e.g., rotating, oscillating, etc.) with respect to other apertures on the tubular spray element. Further, the exterior surface of a tubular spray element may be defined on multiple components of a tubular spray element, i.e., the exterior surface need not be formed by a single integral component.
In addition, in some embodiments a tubular spray element may be discretely directed by a tubular spray element drive to multiple rotational positions about the longitudinal axis to spray a fluid in predetermined directions into a wash tub of a dishwasher during a wash cycle. In some embodiments, a tubular spray element may be mounted on a movable portion of the dishwasher, e.g., a rack, and may be operably coupled to such a drive through a docking arrangement that both rotates the tubular spray element and supplies fluid to the tubular spray element when the tubular spray element is docked in the docking arrangement. In other embodiments, however, a tubular spray element may be mounted to a fixed portion of a dishwasher, e.g., a wash tub wall, whereby no docking arrangement is used. Further details regarding tubular spray elements may be found, for example, in U.S. Pub. No. 2019/0099054 filed by Digman et al., which is incorporated by reference herein.
It will be appreciated, however, that an imaging system consistent with the invention may, in some instances, be used in a dishwasher having other types of spray elements, e.g., rotatable spray arms, fixed sprayers, etc., as well as in a dishwasher having spray elements that are not discretely directable or otherwise controllable or controllably-movable. Therefore, the invention is not limited in all instances to use in connection with the various types of sprayers described herein.
Turning now to the drawings, wherein like numbers denote like parts throughout the several views,
In addition, consistent with some embodiments of the invention, dishwasher 10 may include one or more tubular spray elements (TSEs) 26 to direct a wash fluid onto utensils disposed in racks 18, 20. As will become more apparent below, tubular spray elements 26 are rotatable about respective longitudinal axes and are discretely directable by one or more tubular spray element drives (not shown in
Some tubular spray elements 26 may be fixedly mounted to a wall or other structure in wash tub 16, e.g., as may be the case for tubular spray elements 26 disposed below or adjacent lower rack 18. For other tubular spray elements 26, e.g., rack-mounted tubular spray elements, the tubular spray elements may be removably coupled to a docking arrangement such as docking arrangement 28 mounted to the rear wall of wash tub 16 in
The embodiments discussed hereinafter will focus on the implementation of the hereinafter-described techniques within a hinged-door dishwasher. However, it will be appreciated that the herein-described techniques may also be used in connection with other types of dishwashers in some embodiments. For example, the herein-described techniques may be used in commercial applications in some embodiments. Moreover, at least some of the herein-described techniques may be used in connection with other dishwasher configurations, including dishwashers utilizing sliding drawers or dish sink dishwashers, e.g., a dishwasher integrated into a sink.
Now turning to
As shown in
In the illustrated embodiment, pump 36 and air supply 38 collectively implement a fluid supply for dishwasher 100, providing both a source of wash fluid and pressurized air for use respectively during wash and drying operations of a wash cycle. A wash fluid may be considered to be a fluid, generally a liquid, incorporating at least water, and in some instances, additional components such as detergent, rinse aid, and other additives. During a rinse operation, for example, the wash fluid may include only water. A wash fluid may also include steam in some instances. Pressurized air is generally used in drying operations, and may or may not be heated and/or dehumidified prior to spraying into a wash tub. It will be appreciated, however, that pressurized air may not be used for drying purposes in some embodiments, so air supply 38 may be omitted in some instances, and thus a fluid supply in some embodiments may supply various liquid wash fluids to various sprayers in the dishwasher. Moreover, in some instances, tubular spray elements may be used solely for spraying wash fluid or spraying pressurized air, with other sprayers or spray arms used for other purposes, so the invention is not limited to the use of tubular spray elements for spraying both wash fluid and pressurized air.
Controller 30 may also be coupled to a dispenser 44 to trigger the dispensing of detergent and/or rinse agent into the wash tub at appropriate points during a wash cycle. Additional sensors and actuators may also be used in some embodiments, including a temperature sensor 46 to determine a wash fluid temperature, a door switch 48 to determine when door 12 is latched, and a door lock 50 to prevent the door from being opened during a wash cycle. Moreover, controller 30 may be coupled to a user interface 52 including various input/output devices such as knobs, dials, sliders, switches, buttons, lights, textual and/or graphics displays, touch screen displays, speakers, image capture devices, microphones, etc. for receiving input from and communicating with a user. In some embodiments, controller 30 may also be coupled to one or more network interfaces 54, e.g., for interfacing with external devices via wired and/or wireless networks 56 such as Ethernet, Bluetooth, NFC, cellular and other suitable networks. External devices may include, for example, one or more user devices 58, e.g., mobile devices, desktop computers, etc., and one or more cloud services 60, e.g., as may be provided by a manufacturer of dishwasher 10. Other types of devices, e.g., devices associated with maintenance or repair personnel, may also interface with dishwasher 10 in some embodiments.
Additional components may also be interfaced with controller 30, as will be appreciated by those of ordinary skill having the benefit of the instant disclosure. For example, one or more tubular spray element (TSE) drives 62 and/or one or more tubular spray element (TSE) valves 64 may be provided in some embodiments to discretely control one or more tubular spray elements disposed in dishwasher 10, as will be discussed in greater detail below. Further, an imaging system including one or more cameras 66 (see also
It will be appreciated that each tubular spray element drive 62 may also provide feedback to controller 30 in some embodiments, e.g., a current position and/or speed, although in other embodiments a separate position sensor may be used. In addition, as will become more apparent below, flow regulation to a tubular spray element may be performed without the use of a separately-controlled tubular spray element valve 64 in some embodiments, e.g., where rotation of a tubular spray element by a tubular spray element drive is used to actuate a mechanical valve.
Moreover, in some embodiments, at least a portion of controller 30 may be implemented externally from a dishwasher, e.g., within a user device 58, a cloud service 60, etc., such that at least a portion of the functionality described herein is implemented within the portion of the controller that is externally implemented. In some embodiments, controller 30 may operate under the control of an operating system and may execute or otherwise rely upon various computer software applications, components, programs, objects, modules, data structures, etc. In addition, controller 30 may also incorporate hardware logic to implement some or all of the functionality disclosed herein. Further, in some embodiments, the sequences of operations performed by controller 30 to implement the embodiments disclosed herein may be implemented using program code including one or more instructions that are resident at various times in various memory and storage devices, and that, when read and executed by one or more hardware-based processors, perform the operations embodying desired functionality. Moreover, in some embodiments, such program code may be distributed as a program product in a variety of forms, and that the invention applies equally regardless of the particular type of computer readable media used to actually carry out the distribution, including, for example, non-transitory computer readable storage media. In addition, it will be appreciated that the various operations described herein may be combined, split, reordered, reversed, varied, omitted, parallelized and/or supplemented with other techniques known in the art, and therefore, the invention is not limited to the particular sequences of operations described herein.
Numerous variations and modifications to the dishwasher illustrated in
Furthermore, additional details regarding the concepts disclosed herein may also be found in the following co-pending applications, all of which were filed on even date herewith, and all of which are incorporated by reference herein: U.S. application Ser. No. 16/588,969 (now published as U.S. Pub. No. 2021/0093154), entitled “DISHWASHER WITH IMAGE-BASED OBJECT SENSING,” U.S. application Ser. No. 16/588,034 (now issued as U.S. Pat. No. 11,026,559), entitled “DISHWASHER WITH IMAGE-BASED FLUID CONDITION SENSING,” U.S. application Ser. No. 16/587,820 (now issued as U.S. Pat. No. 11,191,416), entitled “DISHWASHER WITH IMAGE-BASED POSITION SENSOR,” U.S. application Ser. No. 16/588,310 (now published as U.S. Pub. No. 2021/0093152), entitled “DISHWASHER WITH IMAGE-BASED DETERGENT SENSING,” and U.S. application Ser. No. 16/587,826 (now issued as U.S. Pat. No. 11,259,681, entitled “DISHWASHER WITH IMAGE-BASED DIAGNOSTICS.”
Now turning to
Moreover, as illustrated in
Tubular spray element 100 is in fluid communication with a fluid supply 106, e.g., through a port 108 of tubular spray element drive 102, to direct fluid from the fluid supply into the wash tub through the one or more apertures 104. Tubular spray element drive 102 is coupled to tubular spray element 100 and is configured to discretely direct the tubular spray element 100 to each of a plurality of rotational positions about longitudinal axis L. By “discretely directing,” what is meant is that tubular spray element drive 102 is capable of rotating tubular spray element 100 generally to a controlled rotational angle (or at least within a range of rotational angles) about longitudinal axis L. Thus, rather than uncontrollably rotating tubular spray element 100 or uncontrollably oscillating the tubular spray element between two fixed rotational positions, tubular spray element drive 102 is capable of intelligently focusing the spray from tubular spray element 100 between multiple rotational positions. It will also be appreciated that rotating a tubular spray element to a controlled rotational angle may refer to an absolute rotational angle (e.g., about 10 degrees from a home position) or may refer to a relative rotational angle (e.g., about 10 degrees from the current position).
Tubular spray element drive 102 is also illustrated with an electrical connection 110 for coupling to a controller 112, and a housing 114 is illustrated for housing various components in tubular spray element drive 102. In the illustrated embodiment, tubular spray element drive 102 is configured as a base that supports, through a rotary coupling, an end of the tubular spray element and effectively places the tubular spray element in fluid communication with port 108.
By having an intelligent control provided by tubular spray element drive 102 and/or controller 112, spray patterns and cycle parameters may be increased and optimized for different situations. For instance, tubular spray elements near the center of a wash tub may be configured to rotate 360 degrees, while tubular spray elements located near wash tub walls may be limited to about 180 degrees of rotation to avoid spraying directly onto any of the walls of the wash tub, which can be a significant source of noise in a dishwasher. In another instance, it may be desirable to direct or focus a tubular spray element to a fixed rotational position or over a small range of rotational positions (e.g., about 5-10 degrees) to provide concentrated spray of liquid, steam and/or air, e.g., for cleaning silverware or baked on debris in a pan. In addition, in some instances the rotational velocity of a tubular spray element may be varied throughout rotation to provide longer durations in certain ranges of rotational positions and thus provide more concentrated washing in particular areas of a wash tub, while still maintaining rotation through 360 degrees. Control over a tubular spray element may include control over rotational position, speed or rate of rotation and/or direction of rotation in different embodiments of the invention.
In addition, an optional position sensor 122 may be disposed in tubular spray element drive 102 to determine a rotational position of tubular spray element 100 about axis L. Position sensor 122 may be an encoder or hall sensor in some embodiments, or may be implemented in other manners, e.g., integrated into a stepper motor, whereby the rotational position of the motor is used to determine the rotational position of the tubular spray element, or using one or more microswitches and a cam configured to engage the microswitches at predetermined rotational positions. Position sensor 122 may also sense only limited rotational positions about axis L (e.g., a home position, 30 or 45 degree increments, etc.). Further, in some embodiments, rotational position may be controlled using time and programming logic, e.g., relative to a home position, and in some instances without feedback from a motor or position sensor. Position sensor 122 may also be external to tubular spray element drive 102 in some embodiments.
An internal passage 124 in tubular spray element 100 is in fluid communication with an internal passage 126 leading to port 108 (not shown in
In addition, it also may be desirable in some embodiments to incorporate a valve 140 into a tubular spray element drive 102 to regulate the fluid flow to tubular spray element 100. Valve 140 may be an on/off valve in some embodiments or may be a variable valve to control flow rate in other embodiments. In still other embodiments, a valve may be external to or otherwise separate from a tubular spray element drive, and may either be dedicated to the tubular spray element or used to control multiple tubular spray elements. Valve 140 may be integrated with or otherwise proximate a rotary coupling between tubular spray element 100 and tubular spray element drive 102. By regulating fluid flow to tubular spray elements, e.g., by selectively shutting off tubular spray elements, water can be conserved and/or high-pressure zones can be created by pushing all of the hydraulic power through fewer numbers of tubular spray elements.
In some embodiments, valve 140 may be actuated independent of rotation of tubular spray element 100, e.g., using an iris valve, butterfly valve, gate valve, plunger valve, piston valve, valve with a rotatable disk, ball valve, etc., and actuated by a solenoid, motor or other separate mechanism from the mechanism that rotates tubular spray element 100. In other embodiments, however, valve 140 may be actuated through rotation of tubular spray element 100. In some embodiments, for example, rotation of tubular spray element 100 to a predetermined rotational position may be close valve 140, e.g., where valve 140 includes an arcuate channel that permits fluid flow over only a range of rotational positions. As another example, a valve may be actuated through over-rotation of a tubular spray element or through counter rotation of a tubular spray element.
Tubular spray elements may be mounted within a wash tub in various manners in different embodiments, e.g., mounted to a wall (e.g., a side wall, a back wall, a top wall, a bottom wall, or a door) of a wash tub, and may be oriented in various directions, e.g., horizontally, vertically, front-to-back, side-to-side, or at an angle. It will also be appreciated that a tubular spray element drive may be disposed within a wash tub, e.g., mounted on wall of the wash tub or on a rack or other supporting structure, or alternatively some or all of the tubular spray element drive may be disposed external from a wash tub, e.g., such that a portion of the tubular spray element drive or the tubular spray element projects through an aperture in the wash tub. Alternatively, a magnetic drive could be used to drive a tubular spray element in the wash tub using an externally-mounted tubular spray element drive. Moreover, rather than being mounted in a cantilevered fashion as is the case with tubular spray element 100 of
Additional features that may be utilized in a dishwasher including tubular spray elements are described, for example, in U.S. application Ser. Nos. 16/132,091, 16/132,106, 16/132,114, 16/132,125 filed on Sep. 14, 2018 and U.S. application Ser. No. 16/298,007 filed on Mar. 11, 2019, all of which are all assigned to the same assignee as the present application, and all of which are hereby incorporated by reference herein.
Now turning to
An imaging system 170, including, for example, one or more cameras 172, may be used to collect image data within wash tub 152 for a variety of purposes. As noted above, cameras 172 may operate in the visible spectrum (e.g., RGB cameras) in some embodiments, or may operate in other spectra, e.g., the infrared spectrum (e.g., IR cameras), the ultraviolet spectrum, etc. Moreover, cameras 172 may collect two dimensional and/or three dimensional image data in different embodiments, may use range or distance sensing (e.g., using LIDAR), and may generate static images and/or video clips in various embodiments. Cameras may be disposed at various locations within a wash tub, including, for example, on any of walls 154, 156, 158, in corners between walls, on components mounted to walls (e.g., fluid supply conduits), in sump 160, on door 162, on any of racks 164, 166, or even on a spray arm 168, tubular spray element, or other movable component within a dishwasher. Moreover, different types of imaging devices may be used at different locations, or multiple imaging device of different types may be used at the same location (e.g., RGB in one location and IR in another, or RGB and IR in the same location). In addition, an imaging system 170 may also in some embodiments include one or more lights or other illumination devices 174 suitable for illuminating the wash tub to facilitate image collection. Illumination devices 174 may illuminate light in various spectra, including white light, infrared light, ultraviolet light, or even colored light in a particular segment of the visible spectra, e.g. a green, blue, or red light, or patterns of light (e.g., lines, grids, moving shapes, etc.), as may be desirable for particular applications, such as 3D applications. In addition, as illustrated by camera 172a, a camera may also capture image data outside of a wash tub, e.g., to capture images of a rack that has been extended to a loading position.
As noted above, and as is illustrated by cameras 172 and 172a, cameras may be fixed in some embodiments, and it may be desirable to utilize multiple cameras to ensure suitable coverage of all areas of a washtub for which it is desirable to collect image data. In other embodiments only a single camera may be used, and in addition, in some embodiments one or multiple cameras may be disposed on a movable component of a dishwasher to vary the viewpoint of the camera to capture different areas or perspectives within a dishwasher.
As noted above, it may be desirable in some embodiments to additionally incorporate one or more position sensors to determine the position of a tubular spray element or other sprayer in a dishwasher. Position sensor 122 of
A tubular spray element drive 230 includes a motor 232, drive shaft 234 that projects through the wall of manifold 222 and a drive gear 236 that engages with a gear 238 that rotates with tubular spray element 224, such that rotation of drive shaft 234 by motor 232 rotates tubular spray element 224 through the engagement of gears 236, 238. While gears 236, 238 are illustrated as being within manifold 222, in other embodiments, the gears may be external from manifold 222, e.g., on the same side as motor 232, or alternatively, within the wash tub and on the same side as tubular spray element 224.
A cam-based position sensor 240 includes a cam 242 mounted to drive shaft 234 and including a cam lobe 244 defined at a rotational position relative to nozzles 226 of tubular spray element, e.g., at the same rotational position as nozzles 226 in some embodiments. A cam detector 246, e.g., a microswitch, is also positioned at a predetermined position about cam 242 and positioned within a path of travel of cam lobe 244 such that when cam 242 is rotated to a position whereby cam lobe 244 physically engages cam detector 246, a switch is closed and a signal is generated indicating that the tubular spray element 224 is at a predetermined rotational position. In the illustrated embodiment, for example, cam detector 246 is positioned at a top vertical position such that cam detector 246 generates a signal when nozzles 226 are directed straight upwards.
To simplify the discussion, it may be assumed that gears 236, 238 are identically configured such that tubular spray element 224 rotates a full revolution in response to rotation of drive shaft 234 by a full revolution, whereby the rotational position of tubular spray element 224 is derivable directly from the rotational position of drive shaft 234. In other embodiments, however, gears 236, 238 may be differently configured such that a full rotation of drive shaft 234 rotates tubular spray element by less than or more than a full revolution.
It will be appreciated that a cam detector in other embodiments may utilize other sensing technologies. For example, a cam detector may be implemented as a hall or magnetic sensor, and cam lobes on a cam may be implemented using magnets that are sensed by the hall or magnetic sensor when adjacent thereto. As another alternative, a cam detector may include one or more electrical contacts that close an electrical circuit when a cam lobe formed of metal or another electrical conductor engages the cam detector, or may include optical components that sense light or the blockage of light from different holes or durations.
Moreover, while position sensing is performed using a cam coupled to a drive shaft in the embodiment of
It will also be appreciated that a cam-based position sensor may include multiple cam lobes used with one or more cam detectors, and that these multiple cam lobes may rotate about a common axis and within a common plane (as is illustrated in
Returning to
Now turning to
A rotational position of tubular spray element 272 may be defined about its longitudinal axis L, and in some embodiments may be represented using an angle A relative to some home position H (e.g., a top vertical position in the illustrated embodiment, although the invention is not so limited).
The rotational position of tubular spray element 272 may be detected from image data based upon image analysis of one or more images captured from one or more image devices, and in many embodiments, may be based upon detecting one or more visually distinctive features that may be used to determine the current orientation of the tubular spray element about its longitudinal axis L. In some embodiments, for example, distinctive structures defined on the generally cylindrical surface of tubular spray element 272, e.g., nozzles 274, may be detected in order to determine the rotational position.
In other embodiments, however, distinctive indicia 280 that are incorporated into tubular spray element 272 solely or at least partially for purposes of image-based position sensing may be disposed at various rotational positions on the outer surface of tubular spray element 272. In addition, in some instances, as illustrated at 282, the distinctive indicia may be textual in nature. Furthermore, as illustrated at 284, the distinctive indicia may be designed to represent a range of rotational positions, such that image analysis of the indicia may be used to determine a specific rotational position within the range. Indicia 284, for example, includes a series of parallel bars that vary in width and/or spacing such that a location within the series of parallel bars that is visible in a portion of an image can be used to determine a particular rotational position, similar in many respects to the manner that a bar code may be used to retrieve numerical information irrespective of the orientation and/or size of the bar code in an image. Other indicia arrangements that facilitate discrimination of a rotational position out of a range of rotational positions may also be used in some embodiments, e.g., combinations of letters or numbers. In some embodiments, for example, an array of numbers, letters or other distinctive features may circumscribe the generally cylindrical surface of a tubular spray element such that a rotational position may be determined based upon the relative position of one or more elements in the array.
The indicia may be formed in varying manners in different embodiments, e.g., formed as recessed or raised features on a molded tubular spray element, formed using contrasting colors or patterns, integrally molded with the surface of the tubular spray element, applied or otherwise mounted to the surface of the tubular spray element using a different material (e.g., a label or sticker), or in other suitable manners. For example, a reflective window 286 may be used in some embodiments to reflect light within the washtub and thereby provide a high contrast feature for detection. Further, in some embodiments an indicia may itself generate light, e.g., using an LED. It will be appreciated that in some instances, fluid flow, detergent, and/or obstructions created by racks and/or utensils may complicate image-based position sensing, so high contrast indicia may be desirable in some instances to accommodate such challenging conditions.
With reference to
In addition, in some embodiments, image-based position sensing may also be based upon the relationship of a spray pattern to a target, e.g., the example target 298 illustrated in
Now turning to
In addition, nozzles 312 are illustrated in a contrasting color that may also be used to determine the rotational position. Furthermore, each tubular spray element 302 is illustrated with an indicia (a contrasting line) 314 disposed on a docking component of the tubular spray element, which may also be used in image-based position sensing in some embodiments. Other components, e.g., gears, or rotatable components of a docking arrangement, may also include distinct indicia to facilitate position sensing in other embodiments. Furthermore, multiple colors may be used at different locations about the circumference of a tubular spray element to facilitate sensing in some embodiments.
An example process for performing image-based position sensing consistent with the invention is illustrated at 320 in
It will be appreciated that a rotational position may be determined from the detected elements in a number of manners consistent with the invention. For example, various image filtering, processing, and analysis techniques may be used in some embodiments. Further, machine learning models may be constructed and trained to identify the rotational position of a tubular spray element based upon captured image data. A machine learning model may be used, for example, to determine the position of a visually distinctive feature in block 324, to determine the rotational position given the position of a visually distinctive feature in block 326, or to perform both operations to effectively output a rotational position based upon input image data.
In addition, in some embodiments, it may be desirable to monitor for misalignments of a tubular spray element to trigger a recalibration operation. In block 328, for example, if it is known that the position to which the tubular spray element is being driven differs from the sensed position, a recalibration operation may be signaled such that, during an idle time (either during or after a wash cycle) the tubular spray element is recalibrated. In some embodiments, for example, image analysis may be performed to detect when a spray pattern is not hitting an intended target when the tubular spray element is driven to a position where it is expected that the target will be hit. In some embodiments, such analysis may also be used to detect when the spray pattern has deviated from a desired pattern, and recalibration of a flow rate may also be desired (discussed in greater detail below).
Now turning to
Next, once the tubular spray element is rotated to the desired position, one or more images are captured in block 334 while a spray pattern is directed on the target, and image analysis is performed to determine whether the spray pattern is hitting the desired target. If so, no adjustment is needed. If not, however, block 336 may adjust the position of the tubular spray element as needed to focus the tubular spray element on the desired target, which may include continuing to capture and analyze images as the tubular spray element is adjusted.
While image-based position sensing may be used in some embodiments to detect a current position of a tubular spray element in all orientations, in other embodiments it may be desirable to use image-based position sensing to detect only a subset of possible rotational positions, e.g., as little as a single “home” position. Likewise, as noted above, cam-based position sensing generally is used to detect only a subset of possible rotational positions of a tubular spray element. In such instances, it may therefore be desirable to utilize a time-based control where, given a known rate of rotation for a tubular spray element, a tubular spray element drive may drive a tubular spray element to different rotational positions by operating the tubular spray element drive for a predetermined amount of time associated with those positions (e.g., with a rate of 20 degrees of rotation per second, rotation from a home position at 0 degrees to a position 60 degrees offset from the home position would require activation of the drive for 3 seconds). Given a rotation rate of a tubular spray element drive (e.g., in terms of Y degrees per second) and a desired rotational displacement X from a known rotational position sensed by a position sensor, the time T to drive the tubular spray element drive after sensing a known rotational position is generally T=X/Y.
In order to determine the rotation rate of a tubular spray element, a calibration process, e.g., as illustrated at 340 in
In process 340, a tubular spray element is driven to a first position (e.g., a home position as sensed by an image-based position sensor or corresponding to a particular cam detector/cam lobe combination of a cam-based position sensor) in block 342, and then is driven to a second position in block 344, with the time to reach the second position determined, e.g., based upon a timer started when movement to the second position is initiated. The second position may be at a known rotational position relative to the first position, such that the actual rotational offset between the two positions may be used to derive a rate by dividing the rotational offset by the time to rotate from the first to the second position. The rate may then be updated in block 346 for use in subsequent time-based rotation control.
In some embodiments, the first and second positions may be separated by a portion of a revolution, while in some embodiments, the first and second positions may both be the same rotational position (e.g., a home position), such that the rotational offset corresponds to a full rotation of the tubular spray element. In addition, multiple iterations may be performed in some embodiments with the times to perform the various iterations averaged to generate the updated rate.
As an alternative to process 340, calibration of a tubular spray element may be based upon hitting a target, as illustrated by process 350 of
Process 360 begins in block 362 by moving the tubular spray element to a first position. Block 364 then drives the tubular spray element to a second position and determines the time to reach the second position. In addition, during this time images are captured of the spray pattern generated by the tubular spray element. Next, in block 366, blocks 362 and 364 are repeated multiple times, with different flow rates supplied to the tubular spray element such that the spray patterns generated thereby may be captured for analysis. Block 368 then determines a rate parameter in the manner described above (optionally averaging together the rates from the multiple sweeps).
In addition, block 368 may select a flow rate parameter that provides a desired spray pattern. In some embodiments, for example, the spray patterns generated by different flow rates may be captured in different images collected during different sweeps, and the spray patterns may be compared against a desired spray pattern, with the spray pattern most closely matching the desired spray pattern being used to select the flow rate that generated the most closely matching spray pattern selected as the flow rate to be used. In addition, analysis of spray patterns may also be used to control rate of rotation, as it may be desirable in some embodiments to rotate tubular spray elements at slower speeds to increase the volume of fluid directed onto utensils and thereby compensate for reduced fluid flow. Further, in some embodiments, pressure strength may be measured through captured images. As one example, a tubular spray element may be rotated to an upwardly-facing direction and the height of the spray pattern generated may be sensed via captured images and used to determine a relative pressure strength of the tubular spray element.
In addition, as illustrated in block 370, it may be desired in some embodiments to optionally recommend maintenance or service based upon the detected spray patterns. For example, if no desirable spray patterns are detected, e.g., due to some nozzles being partially or fully blocked, it may be desirable to notify a customer of the condition, enabling the customer to either clean the nozzles, run a cleaning cycle with an appropriate cleaning solution to clean the nozzles, or schedule a service. The notification may be on a display of the dishwasher, on an app on the user's mobile device, via text or email, or in other suitable manners.
Now turning to
After focusing spray on the blocked sprayer, block 386 may then attempt to return the blocked sprayer to a known position, and then monitor the position in any of the manners described above. Then, in block 388, if the movement is successful, the wash cycle may resume in a normal manner, and if not, an error may be signaled to the user, e.g., in any various manners mentioned above, for maintenance or service.
Various additional modifications may be made to the illustrated embodiments consistent with the invention. Therefore, the invention lies in the claims hereinafter appended.
Number | Date | Country | |
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Parent | 16588135 | Sep 2019 | US |
Child | 17879343 | US |