CLEANING DEVICE WITH FLUID TANK EMPTY DETECTION

Various cleaning devices with fluid tank empty detection and methods related thereto are provided. In general, a cleaning device can be configured to determine whether a fluid container is empty using an electromotive force (EMF) at a fluid pump configured to pump fluid from the fluid container. When the fluid container becomes empty, fluid cannot be supplied from the cleaning device to a surface until more fluid is added to the fluid container. Thus, by determining whether the fluid container is empty, a user of the cleaning device may be made aware when the fluid container becomes empty and needs refilling (or replacement).

FIELD

The present disclosure generally relates to cleaning devices with fluid tank empty detection.

BACKGROUND

Conventional cleaning devices, such as dry vacuums and wet vacuums, perform cleaning operations using suction to take in waste. Dry vacuums operate through the use of suction and may employ a brushroll or other agitator to assist in freeing the waste from a surface. Wet vacuums operate through the use of suction and an agitator or pad, but they also supply fluid to the to-be-cleaned surface in order to assist in removal of waste. The supply of fluid can occur directly, with fluid being sprayed onto a surface, or indirectly, with fluid being sprayed onto an applicator such as an agitator. Some vacuums are either a dry vacuum or a wet vacuum. Some vacuums are wet dry vacuums able to provide the functionality of a dry vacuum and a wet vacuum.

For wet vacuums and wet dry vacuums, the fluid to be supplied to a surface can be stored on board the device in a fluid container such as a fluid supply tank. The amount of fluid in the fluid container decreases as fluid is supplied to the surface to be cleaned. When the fluid container becomes empty, fluid cannot be supplied from the cleaning device to a surface until more fluid is added to the fluid container. However, a user of the cleaning device may not be aware when the fluid container becomes empty and needs refilling (or replacement) because a user may forget to check the fluid container's fill level before attempting to supply fluid from the cleaning device, the container may be opaque and thus have its fill level obscured from user view; the fluid container may be disposed within another component (e.g., a housing or other component) of the cleaning device and thus have its fill level obscured from user view, or another reason. User experience may thus be degraded by fluid not being available in the fluid container when the user desires to clean using the cleaning device.

Accordingly, there remains a need for improved devices, systems, and methods for cleaning devices.

SUMMARY

In general, systems, devices, and methods for cleaning devices with fluid tank empty detection are provided.

In one aspect, a system is provided that in one embodiment includes a fluid pump of a cleaning device and includes a controller. The fluid pump is configured to pump a fluid from a fluid supply tank for delivery to a surface to be cleaned by the cleaning device. The fluid pump includes a motor configured to drive the pumping of the fluid of and to generate an electromotive force (EMF). The controller is configured to receive from the fluid pump a signal indicative of the EMF and is configured to determine, based on the received signal, whether the fluid supply tank is substantially empty.

The system can have any number of variations. For example, the controller can be configured to, in response to determining that the fluid supply tank is substantially empty, cause a user notification to be provided via the cleaning device indicating that the fluid supply tank is substantially empty.

For another example, the controller receiving the signal can include the controller receiving a plurality of signals from the fluid pump, each of the plurality of signals can be indicative of the EMF generated by the motor during a period of time, and the controller determining whether the fluid supply tank is substantially empty can include the controller comparing the plurality of signals with a predetermined threshold EMF value. Further, the predetermined threshold EMF value can be a preset value that does not change: or the controller can be configured to determine whether the plurality of signals are outside of a predetermined range, if the plurality of signals are not outside of the predetermined range, the predetermined threshold EMF value can remains the same, and if the plurality of signals are outside of the predetermined range, the controller can be configured to change the predetermined threshold EMF value to a new predetermined threshold EMF value. Further, the controller can be configured to calculate the new predetermined threshold EMF value based on the plurality of signals.

For yet another example, the motor can include a rotor and a stator.

For still another example, the system can further include the fluid supply tank.

In another embodiment, a system includes a processor and a memory storing instructions that, when executed by the processor, cause the processor to perform operations including causing a fluid pump of a cleaning device to pump a fluid from a fluid supply tank for delivery to a surface to be cleaned by the cleaning device. The fluid pump includes a motor configured to drive the pumping of the fluid of and to generate an EMF. The operations also include determining, based on generated EMF, whether the fluid supply tank is substantially empty.

The system can vary in any number of ways. For example, the operations can further include, in response to determining that the fluid supply tank is substantially empty, causing a user notification to be provided via the cleaning device indicating that the fluid supply tank is substantially empty.

For another example, determining whether the fluid supply tank is substantially empty can include comparing EMF data received by the processor from the fluid pump with a predetermined threshold EMF value. Further, the predetermined threshold EMF value can be a preset value that does not change: or the operations can further include determining whether the EMF data are outside of a predetermined range, if the EMF data is not outside of the predetermined range, the predetermined threshold EMF value can remain the same, and if the EMF data is outside of the predetermined range, the operations can further include changing the predetermined threshold EMF value to a new predetermined threshold EMF value. Further, the operations can further include calculating the new predetermined threshold EMF value based on the EMF data.

For yet another example, the motor can include a rotor and a stator.

For still another example, the system can further include the fluid supply tank.

In another aspect, a method is provided that in one embodiment includes causing, using a controller, a fluid pump of a cleaning device to pump a fluid from a fluid supply tank for delivery to a surface to be cleaned by the cleaning device. The fluid pump includes a motor configured to drive the pumping of the fluid of and to generate an EMF. The method also includes determining, using the controller and based on generated EMF, whether the fluid supply tank is substantially empty.

The method can have any number of variations. For example, the method can further include, using the controller and in response to determining that the fluid supply tank is substantially empty, causing a user notification to be provided via the cleaning device indicating that the fluid supply tank is substantially empty.

For another example, determining whether the fluid supply tank is substantially empty can include comparing, using the controller, EMF data received by the processor from the fluid pump with a predetermined threshold EMF value. Further, the predetermined threshold EMF value can be a preset value that does not change; or the method can further include determining, using the controller, whether the EMF data are outside of a predetermined range, if the EMF data is not outside of the predetermined range, the predetermined threshold EMF value can remain the same, and if the EMF data is outside of the predetermined range, the method can further include changing, using the controller, the predetermined threshold EMF value to a new predetermined threshold EMF value. Further, the method can further include calculating, using the controller, the new predetermined threshold EMF value based on the EMF data.

For yet another example, the motor can include a rotor and a stator.

DETAILED DESCRIPTION

Further, in the present disclosure, like-named components of the embodiments generally have similar features, and thus within a particular embodiment each feature of each like-named component is not necessarily fully elaborated upon. Additionally, to the extent that linear or circular dimensions are used in the description of the disclosed systems, devices, and methods, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such systems, devices, and methods. A person skilled in the art will recognize that an equivalent to such linear and circular dimensions can easily be determined for any geometric shape.

Various cleaning devices with fluid tank empty detection and methods related thereto are provided. In general, a cleaning device can be configured to determine whether a fluid container is empty using characterizing an electromotive force (EMF) at a fluid pump configured to pump fluid from the fluid container. When the fluid container becomes empty, fluid cannot be supplied from the cleaning device to a surface until more fluid is added to the fluid container. Thus, by determining whether the fluid container is empty, a user of the cleaning device may be made aware when the fluid container becomes empty and needs refilling (or replacement). User experience may thus be improved by allowing fluid to be available in the fluid container when the user desires to clean using the cleaning device.

Some traditional cleaning devices can include a sensor, e.g., a photoelectric sensor, configured to detect whether a fluid container is empty. However, such sensors are expensive and add cost to the cleaning device. The fluid tank empty detection described herein does not use a photoelectric sensor or other type of sensor in detecting whether a fluid container is empty and thus avoids cost of such a sensor. Additionally, such sensors are susceptible to damage by being exposed to fluid since the sensors are used in association with a fluid container. Whether or not the fluid container is empty cannot be determined if the sensor is damaged, thereby reducing functionality of the cleaning device and reducing user experience. The fluid tank empty detection described herein does not use a photoelectric sensor or other type of sensor in detecting whether a fluid container is empty and thus avoids reducing functionality of the cleaning device and reducing user experience due to a damaged sensor. Further, the fluid tank empty detection described herein uses existing components of a cleaning device, e.g., a fluid pump and a controller, and therefore does not add any additional components to the cleaning device in order to achieve fluid tank empty detection, which may help maintain a lower cost of the cleaning device, may free real estate for other components, and/or may allow for a smaller cleaning device.

The systems, devices, and methods described herein are not limited to cleaning devices. The systems, devices, and methods described herein can be similarly used with other types of devices having a fluid supply tank configured to be refilled (or replaced).

FIGS.1-4illustrate one exemplary embodiment of a cleaning device10. The illustrated cleaning device10includes a head assembly100, a body assembly200, a handle assembly300, and a vacuum assembly (obscured inFIGS.1-4). The cleaning device10is shown disposed atop a charging mat400, but the cleaning device10can be configured to not be usable with a charging mat. The device10also includes fluid delivery and fluid recovery assemblies. In this illustrated embodiment, the handle assembly300includes a handle310and a stem320, and the body assembly200includes a body housing210coupled to the stem320. The head assembly100is coupled to the body housing210opposite the stem320. The head assembly100includes a head housing110and includes small wheels (obscured inFIGS.1-4) and large wheels112L,112R rotatably coupled to the head housing110and configured to allow the cleaning device10to roll along a surface. The head assembly100also includes a brushroll (obscured inFIGS.1-4) disposed in the head assembly100and configured to rotate during operation of the cleaning device10. The cleaning device10in this illustrated embodiment is described as including a brushroll, but the cleaning device10can include another type of agitator.

The vacuum assembly is disposed within the head and body assemblies100,200and is capable of taking in fluid, dirt, debris, and other waste through suction and storing it within the cleaning device10. As in this illustrated embodiment, the vacuum assembly can include a motor and a motor fan. The motor and motor fan can be entirely contained in a motor housing disposed within the body assembly200. Hosing230is coupled to the motor fan and runs through the body assembly200to the head assembly100to allow the motor to generate a suction force to draw waste into the device10. Waste taken in by the vacuum assembly through the hosing230is deposited into a recovery tank500removably disposed within the body assembly200. In other embodiments, the recovery tank500may not be removable.

The cleaning device10also include a fluid supply tank600, also referred to herein as a “fluid container.” The fluid supply tank600is configured to contain fluid therein that is configured to be supplied from the device10to a floor or other area to be cleaned. The fluid contained in the fluid supply tank600is clean fluid. The clean fluid can be water, a cleaning solution, or other fluid configured to aid in cleaning the floor or other area to which the fluid is delivered from the device10. Once delivered from the device10, the fluid can be mixed with waste (e.g., dirt, dirty fluid, debris, etc.). The cleaning device10is configured to draw the waste and fluid mixed therewith into the device10with suction generated by the motor and to deposit the drawn-in material in the recovery tank500.

As previously indicated, the cleaning device10is configured to operate in a wet cleaning mode and a dry cleaning mode. The device10can operate in only one of the wet and dry cleaning modes at a time or can operate in the wet and dry cleaning modes simultaneously. The cleaning device10in this illustrated embodiment is configured operate normally in a dry cleaning mode in which the vacuum assembly is employed to suction in waste, but upon selection of the wet cleaning mode, the cleaning device10will also begin to emit fluid to aid in the cleaning process. As discussed further below, the device10includes a user interface302(seeFIG.2) configured to allow user selection of cleaning mode.

Dry cleaning modes generally include modes related to traditional vacuuming operations, such as vacuuming on hard surfaces or on softer surfaces, such as carpet. Dry cleaning modes rely on suction to take waste into the recovery tank of the cleaning device10for convenient disposal. In some dry cleaning modes, the brushroll can rotate to agitate waste on a cleaning surface. The brushroll can loosen the waste while simultaneously directing it toward a suction intake of a cleaning device. In other dry cleaning modes, the brushroll does not rotate (or, in other embodiments, a brushroll is not present), and instead, suction is relied on alone to force waste into the cleaning device10.

Wet cleaning modes generally include the cleaning device10supplying fluid from the fluid supply tank600either directly or indirectly to a surface to aid in cleaning. The supplied fluid can act to loosen waste stuck to the surface, and the dirtied fluid can be taken into the cleaning device through suction or other means. In some wet cleaning modes, like some dry cleaning modes described above, the brushroll can further assist in loosening waste off the surface and directing it toward a suction intake. In these wet cleaning modes, the fluid can be supplied directly to the brushroll in order to simultaneously apply the fluid to the surface while agitating the waste found on the surface. In other wet cleaning modes, the fluid can be supplied directly to the surface and the brushroll can agitate the wetted surface. In still other modes, the fluid can be supplied directly to the surface and the brushroll can remain stationary (or, in other embodiments, a brushroll is not present), thereby cleaning the surface with fluid and suction alone.

As shown inFIGS.5and6, the body assembly200is configured to be operatively coupled to the head assembly100via an articulator250. The articulator250is coupled to the bottom of the body assembly200and is configured to at least partially disposed within the head assembly100. The illustrated articulator250is configured to articulate about two degrees of freedom. A first point of articulation254, allowing for articulation about a first degree of freedom, is mounted within the head assembly100. The first point of articulation254allows for the body assembly200to pivot between a forward direction and a backward direction, as indicated by the arrows A-A inFIGS.5and6. A second point of articulation256, located above the first point of articulation254, allows for the body assembly200to pivot between a left direction and a right direction, as indicated by the arrows B-B inFIG.5. One or both of the first and second points of articulation254,256can be articulated at a given time. Further, in other embodiments, the body assembly200can be configured to articulate in any number of degrees of freedom about any number of points of articulation.

As also shown inFIGS.5and6, the body housing210of the body assembly200includes a housing base210a, a front side210b, a rear side210cextending upward from the housing base210a, and a top side210d. The top side210dof the body housing210is coupled to the handle assembly300, which extends from the body assembly200in a direction opposite the head assembly100.

As shown inFIGS.7and8, the body housing210of the body assembly200includes first and second cavities210e,210fconfigured to removably receive components of the cleaning device10. The first cavity210eis configured to removably receive the recovery tank therein, as shown inFIGS.5and6. The second cavity210fis configured to removably seat the fluid supply tank600therein, as shown inFIGS.5and6.FIGS.7and8show the body assembly200with the recovery tank and the fluid supply tank600removed from the first and second cavities210e,210f, respectively.

The first cavity210e, located in the front side210bof the body housing210, is sized to removably receive the recovery tank such that, when retained in the first cavity210e, the recovery tank occupies the entirety of a lower region of the front side210bof the body housing210. The recovery tank is removable from the body housing210after actuation of a latch assembly430) (seeFIGS.5and6extending outward from an upper extent of the recovery tank. The actuation of the latch assembly430releases the recovery tank from engagement with a retaining slot214(seeFIG.8) that is located toward the front of the first cavity210e.

The second cavity210fis located in an upper front portion210bof the body housing210and occupies a substantial portion of the top side210d. The second cavity210gfis sized to removably receive the fluid supply tank600. A fluid tank switch212(seeFIGS.7and8) is disposed in the top side210dof the body housing210. With the fluid supply tank600seated in the second cavity210f, a tank engagement feature216(seeFIG.7) of the body assembly200extends from the body housing210and is engaged with the fluid supply tank600to lock the fluid supply tank600to the body housing210. When the fluid tank switch212is actuated, the tank engagement feature216recedes into the body housing210, which allows the fluid supply tank600to be removed from the second cavity210f.

FIGS.9-12illustrate the fluid supply tank600as a standalone element. As shown inFIGS.9-12, the fluid supply tank600includes a valve cap612removably threaded to a fluid tank614. The fluid tank614is divided into an upper tier614aand a lower tier614b. Each of the tiers614a.614bhas a substantially hemi-cylindrical shape in this illustrated embodiment but may have other shapes. The upper tier614ais shaped to conform with the overall form of the body housing210and provides an outer limit for the upper front face210bof the body housing210. The lower tier614bis smaller than the upper tier614ain this illustrated embodiment and is configured to be received internally within the body housing210. The fluid tank614defines a hollow interior, which receives the fluid to be supplied by the cleaning device10during a wet cleaning operation.

The valve cap612of the fluid supply tank600permits one-way flow of fluid therethrough from the hollow interior of the fluid tank614to externally thereof. The valve cap612is configured to be received in the second cavity210fof the body housing210in a complementary recess. When the valve cap612is properly seated in the second cavity210f, fluid is able to flow therethrough. When the valve cap612is not properly seated in the second cavity210f, the valve cap612acts to seal the fluid within the fluid supply tank600.

The valve cap612of the fluid supply tank600is removably coupled to the lower tier614avia a threaded connection, although other connection types are possible such as a hinged lid, etc. When the fluid supply tank600is not removably coupled with the body housing210, the valve cap612is accessible to a user. The valve cap612is configured to be removed from a remainder of the fluid supply tank600, e.g., by being unscrewed by hand, to allow fluid to be added into the hollow interior of the fluid supply tank600, e.g., by being poured therein through an opening uncovered by removal of the valve cap612, and/or for fluid to be removed from the hollow interior of the fluid supply tank600, e.g., by being poured out of the opening uncovered by removal of the valve cap612.

The lower tier614bincludes a bleeder valve616and a retention depression618. As the fluid tank614empties of fluid, the bleeder valve616is configured to allow for an equalization of pressure in the hollow interior to facilitate a constant supply of fluid to the cleaning device10, without creating a vacuum within the hollow interior. The retention depression618in this illustrated embodiment is a depression formed in the lower tier614bwhich is shaped to receive the tank engagement feature216of the body assembly200although other configurations are possible for a retention feature configured to engage the tank engagement feature216. As explained above, actuation of the fluid tank switch212is configured to allow for the fluid supply tank600to be removed from the second cavity210f. More specifically, actuation of the fluid tank switch212is configured to retract the tank engagement feature216into the body housing210so that it no longer engages the retention depression618.

FIG.13illustrates various components, including tubing620, a fluid pump622(also shown inFIG.18), and fluid application face624, and spray nozzles630, configured to facilitate delivery of fluid from the fluid supply tank600to a surface for cleaning. The fluid pump622is configured to pump fluid from the fluid supply tank600through the cleaning device10by providing a force that draws fluid out of the fluid supply tank600. The fluid supply tank600, when removably coupled with the body assembly200, is in fluid communication with the spray nozzles630by way of the fluid pump622and the tubing620. When fluid leaves the fluid supply tank600, e.g., under a pumping force provided by the pump622, the fluid is transported through the cleaning device10in the tubing620. The tubing620connects to the fluid supply tank610, travels down the body assembly200, and then travels into the head assembly100. More particularly, the tubing620connects the fluid supply tank600to the pump622and then leaves the pump622before splitting and finally connecting to left and right spray nozzles630disposed on the fluid application face624of the head assembly100. In other embodiments, the spray nozzles630can be located elsewhere in the head assembly100and/or can include a different number of nozzles.

Waste (if any) outside the device10mixes with the emitted fluid and creates a slurry which is then suctioned into the cleaning device10through a central intake (obscured in the figures) of the head assembly100. From the central intake, the slurry travels up through the hosing230and into the recovery tank420.

The cleaning device10is configured to allow a user to select wet and dry cleaning modes using the user interface302. The user interface302is located at the handle assembly300in this illustrated embodiment, as shown inFIGS.2,14and17in which the user interface302is located on a handle frame312of the handle assembly300, but the user interface302can also or instead be located elsewhere, such as at another area of the handle assembly300, at the head assembly100, and/or at the body assembly200.

As shown inFIGS.14and17, the handle310of the handle assembly300includes the handle frame312and the stem320. The stem320defines and surrounds an interior handle aperture314. The stem320) in this illustrated embodiment is substantially linear and has a rear face322and a front face324. A person skilled in the art will appreciate that an element may not be precisely linear but nevertheless be considered substantially linear for any number of reasons, such as manufacturing tolerances and sensitivity of measurement equipment. A person skilled in the art will also appreciate that the handle assembly300can have a variety of other configurations.

As shown inFIGS.14-17, the illustrated handle frame312has a bottom section312a, a front section312b, and a back section312cextending upward from the bottom section312aat substantially right angles relative to the bottom section312a. A person skilled in the art will appreciate that an angle may not be precisely a right angle but nevertheless be considered a substantially right angle for any number of reasons, such as manufacturing tolerances and sensitivity of measurement equipment. A top of each of the front section312band the back section312care connected by a top section312dof the handle frame312. The user interface302is located on the front section312bof the handle frame312in this illustrated embodiment but may be located elsewhere, such as on another section312a,312c,312dof the handle frame312, on the body assembly200, and/or on the head assembly100.

The user interface302can have a variety of configurations. In some embodiments, the user interface302includes a touchscreen display configured to receive user inputs by touch and to display information thereon for visualization by a user. In some embodiments, the user interface302, whether including a touchscreen display or not, includes a plurality of input buttons and/or other controls that permit a user to configure operation of the cleaning device10by providing various inputs as described herein. For example, in some embodiments, the user interface302can include a rotary function dial configured to rotate when turned by a user such that the user can select wet and dry cleaning modes mode in which the cleaning device10can operate. For another example, the user interface302can include a start/stop button, which, when pressed by a user, causes the controller350to start and/or stop various operation of the cleaning device10in the selected mode. For yet another example, the user interface302can include one or more indicators (e.g., light(s), display(s), speaker(s), etc.) which indicate a status of the cleaning device10. The one or more indicators can include, for example, any one or more of a fluid supply tank empty indicator that indicates whether the fluid supply tank600is empty, a mode indicator that indicates which cleaning mode is selected, a power status indicator that indicates whether the cleaning device10is powered on, etc.

The handle assembly300also includes a power button330disposed on the front section312bof the handle frame312, although the power button330may be located elsewhere, such as on the back section312c, the stem320, as part of the user interface302, or elsewhere. The power button330is configured to be actuated by a user to turn the device10on and off.

The handle assembly300also includes an area rug button340disposed on a front exterior of the top section312dof the handle frame312, although the area rug button340may be located elsewhere, such as on the back section312c, the stem320, as part of the user interface302, or elsewhere. The area rug button340is configured to be actuated by a user to activate an area rug mode when an area rug is to be cleaned using the cleaning device10. In the area rug mode, some bleed air is provided to reduce air flow at the central intake.

In some embodiments, the power button330and/or the area rug button340can be omitted with the functionality of the omitted button(s) instead being provided via the user interface302.

The user interface302, the power button330, and the area rug button340are in operable communication with a controller350, which is illustrated inFIG.18. The user interface302, the power button330, and the area rug button340are configured to receive inputs from a user that cause the controller350to perform one or more operations responsive to the received inputs, as described further herein.

The controller350of the cleaning device10is configured to be in operable communication with various components of the cleaning device10, including the user interface302, the power button330, the area rug button340, the pump622, and a power supply360(e.g., a battery or other source of power). As in this illustrated embodiment, the controller350) can include a processor352and a memory354configured to store instructions which, when executed by the processor352, cause the processor352to perform operations. The controller350in this illustrated embodiment also includes an input/output (I/O) interface356that enables the processor350to receive commands and/or data from other components of the cleaning device10for use in performing the operations. For example, the controller350can receive, through the I/O interface356, data, e.g., a voltage value, from the fluid pump622mcharacterizing an electromotive force (EMF) and provide that data to the processor352for use in performing operations requiring the received EMF data as an input, as described further herein. Similarly, the controller350) can receive, from the user interface302, the power button330, and the area rug button340) and via the I/O interface68, data characterizing inputs received from the user by the user interface302, the power button330, and the area rug button340) and provide that data to the processor352for use in performing operations that require the data received therefrom as input.

As shown inFIG.18, the cleaning device10includes a printed circuit board (PCB)370including various components, which in this illustrated embodiment include the controller350, configured to facilitate operation of the cleaning device10. The PCB370can have a variety of configurations and, in some embodiments, the controller350) can be included in the cleaning device10without use of a PCB.

The PCB370is located at a control unit380of the cleaning device10. The control unit380is located at the handle assembly300in this illustrated embodiment, as shown inFIG.16, but can be located elsewhere, such as at the head assembly100or the body assembly200.

The cleaning device10also includes the power supply360that is configured to supply power to various components of the cleaning device10requiring power to operate. The power supply360is in operable communication with the controller350. The power supply360is configured to receive commands from the controller350, provided via the I/O interface356, that cause the power supply360to provide electrical power to components as needed in reply to the power button330being actuated and to cease providing electrical power to components as needed in reply to the power button330being actuated again.

The fluid pump622is an electric pump that includes a pump motor622mconfigured to provide a driving force that causes fluid to be drawn out of the fluid supply tank600. In an exemplary embodiment, the motor622mis a brushless direct current (BLDC) motor or other type of motor that includes a rotor622rand a stator622s. The rotor622ris configured to rotate. The rotor622rcan include a permanent magnet, and the stator622scan include metallic coils electrically coupled to a DC source638(seeFIG.19). DC current provided to the stator622sfrom the DC source638is configured to create an electromagnetic field, which is configured to cause the rotor622rto rotate such that the pump motor622mcan provide a rotational driving force configured to cause fluid to be drawn out of the fluid supply tank600. The fluid pump622is operably coupled with the controller350, as shown inFIG.18, to facilitate fluid supply tank600empty detection based on the created EMF, as discussed further herein.

One exemplary embodiment of a control circuit619including the fluid pump622is shown inFIG.19and includes a MOSFET632, a first transistor634, a second transistor636, and the DC source638. The DC source638is a 14 V source in this illustrated embodiment, although other voltage values are possible.

During a wet cleaning operation, the amount of fluid in the fluid supply tank600decreases because fluid is pumped out of the fluid supply tank600. In the course of performing one or more wet cleaning operations, the fluid supply tank600will become substantially depleted of fluid and thus be substantially empty. A person skilled in the art will appreciate that a fluid supply tank may not be completely empty, e.g., because one or more droplets of fluid are stuck to an interior surface of the fluid supply tank, but nevertheless be considered to be substantially empty.

When the supply of fluid in the fluid supply tank600is determined to be empty, as discussed further herein, the cleaning device10is prevented from operating in a wet cleaning operation, e.g., by the controller350) causing the pump622to stop pumping fluid (or not start if the pump622was not already pumping fluid). Additionally, the cleaning device10is configured to provide a user notification, e.g., the controller350is configured to cause the user notification to be provided via the user interface302, that the fluid supply tank600must be refilled (or replaced) before a wet cleaning operation can begin, or, if a wet cleaning operation was in progress, can continue. The user notification can be visual and/or audible. The user notification can include, for example, a water droplet or other symbol being shown on a display of the user interface302. The user notification can include, for example, text being shown on a display of the user interface302. For another example, the user notification can include a light illuminating (solid illumination or blinking illumination) via the user interface302. For yet another example, the user notification can include an audible one or more beeps or other sounds provided via the user interface302.

In an exemplary embodiment, the controller350(e.g., the processor352thereof) is configured to determine whether the fluid supply tank600is empty using EMF data received from the pump622. The EMF data is indicative of the EMF created by the pump motor622mand, more particularly, the EMF generated by the motor as a rotating element of the motor622m, e.g., the rotor622rof the pump motor622m, rotates while the pump622is running in a pulse width modulated duty cycle.

In response to the fluid pump622being turned on and receiving a control signal, e.g., a pulse width modulated (PWM) signal, from the first transistor634, the MOSFET632receives DC current from the DC source638. The pump motor's rotor622rwill therefore begin to rotate and an EMF will be created. The MOSFET632is generally acting as a generator. The controller350) is configured to receive a signal from the fluid pump622indicative of the EMF. The EMF runs in the circuit619to the controller350, and in particular to the second transistor636of the controller350).

In response to the fluid pump622being turned off, the MOSFET632stops receiving DC current from the DC source638and the rotor622rthus stops rotating. The rotor's rotation does not stop immediately when the fluid pump622is turned off. Instead, inertia causes the rotor622rto continue rotating for a period of time after the fluid pump622has been turned off and stops receiving DC current. The EMF will continue being created during this period of time. The controller350) (e.g., the second transistor636thereof) continues receiving the EMF signal for the period of time after the fluid pump622has been turned off.

The controller350(e.g., the processor352thereof) is configured to determine whether the fluid supply tank600is empty based on the received EMF signal. In general, if the EMF signal is less than a predetermined threshold EMF value, then the fluid supply tank600is determined to not be substantially empty, and if the EMF signal is greater than the predetermined threshold EMF value, then the fluid supply tank600is determined to be substantially empty. As discussed herein, in response to determining that the fluid supply tank600is substantially empty, the controller350) (e.g., the processor352thereof) is configured to cause a user notification to be provided indicating that the fluid supply tank600must be refilled (or replaced).

With fluid present in the fluid supply tank600, the fluid pump622runs with a load. Conversely, with the fluid supply tank600being substantially empty, the load is not present. The EMF created after the pump622has been turned off while the rotor622ris still rotating due to inertia will therefore be higher when the fluid supply tank600is substantially empty than when the fluid supply tank600is not substantially empty.

FIG.20illustrates a graph700showing one embodiment of EMF versus time.FIG.20shows two periods of time702,704when a fluid supply tank (e.g., fluid supply tank600or other fluid supply tank) is substantially empty and another period of time706when the fluid supply tank is not substantially empty. As shown inFIG.20, the EMF is higher when the fluid supply tank is substantially empty. The EMF can therefore be used by the controller350is determining whether the fluid supply tank600is substantially empty or not.

The predetermined threshold EMF value is preset. e.g., stored in the memory354of the controller350, for a particular cleaning device10. In an exemplary embodiment, the predetermined threshold EMF value is about halfway between an EMF value with the fluid supply tank600being substantially empty and an EMF value with the fluid supply tank600not being substantially empty. Being about halfway between these EMF values may help prevent false positives, e.g., prevent the controller350from determining that the fluid supply tank600is substantially empty when the fluid supply tank600still contains fluid therein that could be pumped out of the fluid supply tank600and delivered from the cleaning device10to a surface. Different cleaning devices can have different fluid supply tanks and/or different fluid pumps, so the predetermined threshold EMF value can vary for different cleaning devices. The predetermined threshold EMF value can thus be determined experimentally. In the example ofFIG.20, the predetermined threshold EMF value can be selected to be a voltage value of about 30,000, which is about halfway between an EMF value with the fluid supply tank600is substantially empty and an EMF value with the fluid supply tank600is not substantially empty.

The predetermined threshold value EMF is valid even if the cleaning device10is operating in different wet cleaning modes. In some embodiments, the cleaning device10is configured to operate in different wet cleaning modes, such as a bare floor wet cleaning mode, rug wet cleaning mode, and cleaning device self-cleaning mode. In different wet cleaning modes, the controller (e.g., the processor352) thereof is configured to cause fluid to be pumped from the fluid supply tank600at different rates. For example, fluid can be pumped from the fluid supply tank600at a lower rate for cleaning bare floors than for cleaning a rug. For another example, fluid can be pumped from the fluid supply tank600at a higher rate for cleaning device10self-cleaning than for surface cleaning.

FIG.21illustrates a graph800showing one embodiment of EMF versus time for a bare floor wet cleaning mode.FIG.22illustrates a graph802showing one embodiment of EMF versus time for a rug wet cleaning mode.FIG.23illustrates a graph804showing one embodiment of EMF versus time for a first, low flow self-cleaning cleaning mode, andFIG.24illustrates a graph806showing one embodiment of EMF versus time for a second, high flow self-cleaning cleaning mode. As demonstrated byFIGS.21-24, a predetermined threshold EMF value of about 30,000 is valid for all of the illustrated wet cleaning modes.

FIG.25shows first and second graphs900,902over time and illustrating EMF being higher when a fluid supply tank of a cleaning device (e.g., the cleaning device10or other cleaning device) is substantially empty as compared to when the fluid supply tank is not substantially empty. The first graph900shows a first line904representing power to a fluid pump of the cleaning device (e.g., the fluid pump622or other fluid supply tank) and a second line906representing an EMF created at the fluid pump, e.g., by rotation of a rotor of the fluid pump. The EMF begins to change when the power to the fluid pump stops and begins to decrease, as shown by the second line906sloping downward at a first slope after a first period of time has elapsed from the stop of power. The second graph902shows a third line908representing power to the fluid pump and a fourth line910representing an EMF created at the fluid pump. The EMF begins to change when the power to the fluid pump stops and begins to decrease, as shown by the fourth line910sloping downward at a second slope after a second period of time has elapsed from the stop of power.

As shown inFIG.25, the first period of time is less than the second period of time, which reflects that the load experienced by the fluid pump is greater in the scenario shown in the first graph900than in the scenario shown in the second graph902because the fluid supply tank is not substantially empty in the scenario illustrated in the first graph900and is substantially empty in the scenario illustrated in the second graph902. The first line904therefore begins sloping downward sooner in response to power stopping than the third line908begins sloping downward in response to power stopping because the fluid pump's rotor stops rotating sooner in the scenario illustrated in the first graph900than in the scenario illustrated in the second graph902. Also, the first slope of the first line904is greater than the second slope of the third line908, which also reflects that the load experienced by the fluid pump is greater in the scenario shown in the first graph900than in the scenario shown in the second graph902.

FIG.26illustrates one embodiment of a method1000of fluid tank empty detection. The method1000is described with respect to the cleaning device10ofFIGS.1-4for ease of explanation but can be similarly performed with respect to another cleaning device or another type of device having a fluid supply tank configured to be refilled (or replaced).

The method1000includes the fluid pump622pumping1002fluid from the fluid supply tank600. The pumping can start pumping1002by a user providing an input to the cleaning device10, e.g., by the user pressing an on/off switch (as shown inFIG.26) or by the user providing another input. The user's input is received by the controller350(e.g., the processor352thereof) and causes the controller350(e.g., the processor352thereof) to transmit a signal to the fluid pump622that causes the fluid pump622to start pumping and thereby start drawing fluid out of the fluid supply tank600.

After running for a period of time during which fluid is drawn from the fluid supply tank600, the fluid pump622stops1004pumping. The pump622is shown inFIG.26as pumping1002for five seconds with the pump622running at 5 Hz before stopping1004, but another period of time of pumping1002and another frequency are possible. The pumping can stop1004pumping by a user providing an input to the cleaning device10, e.g., by the user pressing an on/off switch or by the user providing another input. The user's input is received by the controller350) (e.g., the processor352thereof) and causes the controller350(e.g., the processor352thereof) to transmit a signal to the fluid pump622that causes the fluid pump622to stop1004pumping and thereby stop drawing fluid out of the fluid supply tank600.

The controller350(e.g., the processor352thereof) waits1004for a predetermined period of time delay after the pumping stops1004before the controller350(e.g., the processor352thereof) begins reading1004EMF data (identified as “Back_EMF value” inFIG.26) from the fluid pump622on a regular periodic basis. The regular periodic basis is every 2 ms inFIG.26but other regular periodic bases are possible. The predetermined period of time delay is 5 ms inFIG.26, but another predetermined period of time delay is possible. Waiting the predetermined period of time delay, e.g., as counted by a counter or timer of the controller350) that is in operable communication with the processor352, reflects noise at the pump622immediately after stopping1004. The fluid pump622continues running for a period of time after stopping1004because the electric motor622mof the fluid pump622cannot instantaneously stop completely, as discussed above. The first and third lines904,908of the first and second graphs900,902, respectively, ofFIG.26reflect noise in such a period of time before the first and third lines904,908begin sloping downward.

After each read1004of the EMF data, the controller350(e.g., the processor352thereof) determines1006whether a predetermined number of EMF data reads1004have occurred, e.g., if a predetermined number of EMF data points have been acquired. The predetermined number of EMF data reads is twenty inFIG.26, but other numbers are possible. If the predetermined number of EMF data reads1004has not occurred, then the controller350) (e.g., the processor352thereof) continues reading1004EMF data.

If the predetermined number of EMF data reads1004has occurred, then the controller350(e.g., the processor352thereof) calculates1008a sum of the predetermined number of EMF data reads1004, e.g., adds together the acquired EMF values. The calculation1008roughly calculates an area of the back electromotive force of the fluid pump622. For example, with reference to the example ofFIG.25, the calculation1008for EMF data of the first graph900roughly calculates an area under the first line904and for EMF data of the second graph902roughly calculates an area under the third line908.

Referring again toFIG.26, the controller350(e.g., the processor352thereof) then determines1010whether the sum continuously exceeds the predetermined threshold EMF value (identified as “threshold A” inFIG.26) for a predetermined amount of time. The predetermined amount of time is three seconds inFIG.26, but another predetermined amount of time is possible. If the sum does not continuously exceed the predetermined threshold EMF value for the predetermined amount of time, the controller350) (e.g., the processor352thereof) continues reading1004EMF data from the fluid pump622on the regular periodic basis. This reflects that the fluid supply tank600is not substantially empty and that fluid can therefore continue being pumped from the fluid supply tank600.

If the sum does continuously exceed the predetermined threshold EMF value for the predetermined amount of time, the controller350) (e.g., the processor352thereof), the fluid pump622stops1012running and a user notification is provided1012that the fluid supply tank600must be refilled (or replaced) before a wet cleaning operation can begin, or, if a wet cleaning operation was in progress, can continue. This reflects that the fluid supply tank600is substantially empty and that fluid cannot be pumped from the fluid supply tank600until the fluid supply tank600is refilled (or replaced). e.g., that the method1000has ended1014until the fluid supply tank600is refilled (or replaced) and pumping1002may begin again. The fluid pump622can stop1012running by the controller350(e.g., the processor352thereof) transmitting a signal to the fluid pump622that causes the pump622to stop pumping, e.g., for the motor622mto stop running. The user notification can be provided1012in any number of ways, as discussed above.

FIG.27illustrates another embodiment of a method1100of fluid tank empty detection. The method1100is described with respect to the cleaning device10ofFIGS.1-4for ease of explanation but can be similarly performed with respect to another cleaning device or another type of device having a fluid supply tank configured to be refilled (or replaced).

In the method1000ofFIG.26, the predetermined threshold EMF value is preset and remains the same throughout performance of the method1000. Conversely, in the method1100ofFIG.27, the predetermined threshold EMF value is initially at a preset value, but that value may change during performance of the method1100. The method1100ofFIG.27reflects that the cleaning device10can be configured to perform self-leaning or machine learning that results in the predetermined threshold EMF value being changed to another value. Self-learning or machine learning may allow for more accurate empty tank detection over time because electric motors experience wear and tear over time that can affect the created EMF. As discussed further below, the self-learning or machine learning is only conducted when the pump622is running and the EMF value is less than the threshold value which means that the fluid supply tank600is not empty.

The method1100includes the fluid pump622pumping1102fluid from the fluid supply tank600. The pumping can start pumping1102by a user providing an input to the cleaning device10, e.g., by the user pressing an on/off switch (as shown inFIG.27) or by the user providing another input. The user's input is received by the controller350(e.g., the processor352thereof) and causes the controller350(e.g., the processor352thereof) to transmit a signal to the fluid pump622that causes the fluid pump622to start pumping and thereby start drawing fluid out of the fluid supply tank600. The user's input being received by the controller350(e.g., the processor352thereof) also causes the controller350(e.g., the processor352thereof) to read1102the predetermined threshold EMF value (identified as “flash data threshold A” inFIG.27) from the memory354.

After running1104for a period of time during which fluid is drawn from the fluid supply tank600, the controller350(e.g., the processor352thereof) begins reading1106EMF data (identified as “Back_EMF Data” inFIG.27) from the fluid pump622on a regular periodic basis. The pump622is shown inFIG.27as running1104for five seconds, but another period of time of running1104is possible. The regular periodic basis is every 1 second inFIG.27but other regular periodic bases are possible. After each read1106of the EMF data, the controller350) (e.g., the processor352thereof) determines1108whether a predetermined number of EMF data reads1106have occurred, e.g., if a predetermined number of EMF data points have been acquired. The predetermined number of EMF data reads is thirty-two inFIG.27, but other numbers are possible.

If the predetermined number of EMF data reads1106has occurred, then the controller350(e.g., the processor352thereof) calculates1110a potential new predetermined threshold EMF value (identified as “threshold F for self-learning” inFIG.27). The potential new predetermined threshold EMF value is calculated1110by averaging the read1106EMF data and adding a predetermined value. For example, for an initial predetermined threshold EMF value of 30,000 (as discussed above) the predetermined value added to the average EMF can be 20,000. The potential new predetermined threshold EMF value can be calculated1110by the controller350(e.g., the processor352thereof) only when the fluid supply tank600had at least some fluid therein that the pump622pumped from the fluid supply tank600. Otherwise, no EMF data could have been acquired1106for performance of the calculation1110.

After calculating1110the potential new predetermined threshold EMF value, the controller350(e.g., the processor352thereof) determines1112whether the potential new predetermined threshold EMF value is within a predetermined range of the predetermined threshold EMF value. The predetermined range is +/−5,000 inFIG.27, but another predetermined range is possible. If potential new predetermined threshold EMF value is within the predetermined range of the predetermined threshold EMF value, the controller350(e.g., the processor352thereof) resets1114the calculator (e.g., the controller350(e.g., the processor352thereof) that calculated1110the potential new predetermined threshold EMF value resets) and continues reading1106EMF data from the fluid pump622on the regular periodic basis. This reflects that the predetermined threshold EMF value remains the same.

If the potential new predetermined threshold EMF value is not within the predetermined range of the predetermined threshold EMF value, the potential new predetermined threshold EMF value is assigned1116as the predetermined threshold EMF value. Such assigning1116can be performed by the controller350(e.g., the processor352thereof) causing the potential new predetermined threshold EMF value to be stored as the predetermined threshold EMF value in volatile memory of the memory624.

After setting1116the new predetermined threshold EMF value, the controller350(e.g., the processor352thereof) determines1118whether the fluid pump622has not stopped running, which is shown inFIG.27as the cleaning device10entering a standby mode. If the fluid pump622has stopped running, then the controller350(e.g., the processor352thereof) continues reading1106EMF data.

If the fluid pump622has stopped running1004, then the controller350(e.g., the processor352thereof) saves1120the potential new predetermined threshold EMF value as the predetermined threshold EMF value. Such saving1120can be performed by the controller350(e.g., the processor352thereof) causing the potential new predetermined threshold EMF value to overwrite the predetermined threshold EMF value in non-volatile memory (shown inFIG.27as “flash” memory) of the memory624. The method1100then ends1122until the pumping begins again.

If the predetermined number of EMF data reads1106has not occurred, then the controller350(e.g., the processor352thereof) determines1124whether the pump622has stopped running. If not, then the controller350(e.g., the processor352thereof) continues reading1106EMF data. If so, then the controller350) (e.g., the processor352thereof) resets1126the calculator, similar to the resetting1114discussed above, and the method ends1122as discussed above.

The methods1000,1100ofFIGS.26and27can each be implemented in the cleaning device10such that the device10is configured to perform self-learning. Alternatively, only the method1000ofFIG.26can be implemented in the cleaning device10such that the device10is not configured to perform self-learning.

One skilled in the art will appreciate further features and advantages of the devices, systems, and methods based on the above-described embodiments. Accordingly, this disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety for all purposes.

The present disclosure has been described above by way of example only within the context of the overall disclosure provided herein. It will be appreciated that modifications within the spirit and scope of the claims may be made without departing from the overall scope of the present disclosure.