Autonomous coverage robot

A mobile surface cleaning robot including a robot body having a forward drive direction, a drive system supporting the robot body above a floor surface for maneuvering the robot across the floor surface, and a robot controller in communication with the drive system. The robot also includes a collection volume supported by the robot body and a cleaning module releasably supported by the robot body and arranged to clean the floor surface. The cleaning module includes a first vacuum squeegee having a first duct, a driven roller brush rotatably supported rearward of the first vacuum squeegee, a second vacuum squeegee disposed rearward of the roller brush and having a second duct, and a third duct in fluid communication with the first and second ducts. The third duct is connectable to the collection volume at a fluid-tight interface formed by selectively engaging the cartridge with the robot body.

TECHNICAL FIELD

This disclosure relates to surface cleaning robots.

BACKGROUND

Wet cleaning of household surfaces has long been done manually using a wet mop or sponge. The mop or sponge is dipped into a container filled with a cleaning fluid to allow the mop or sponge to absorb an amount of the cleaning fluid. The mop or sponge is then moved over the surface to apply a cleaning fluid onto the surface. The cleaning fluid interacts with contaminants on the surface and may dissolve or otherwise emulsify contaminants into the cleaning fluid. The cleaning fluid is therefore transformed into a waste liquid that includes the cleaning fluid and contaminants held in suspension within the cleaning fluid. Thereafter, the sponge or mop is used to absorb the waste liquid from the surface. While clean water is somewhat effective for use as a cleaning fluid applied to household surfaces, cleaning is typically done with a cleaning fluid that is a mixture of clean water and soap or detergent that reacts with contaminants to emulsify the contaminants into the water.

The sponge or mop may be used as a scrubbing element for scrubbing the floor surface, and especially in areas where contaminants are particularly difficult to remove from the household surface. The scrubbing action serves to agitate the cleaning fluid for mixing with contaminants as well as to apply a friction force for loosening contaminants from the floor surface. Agitation enhances the dissolving and emulsifying action of the cleaning fluid and the friction force helps to break bonds between the surface and contaminants.

After cleaning an area of the floor surface, the waste liquid is rinsed from the mop or sponge. This is typically done by dipping the mop or sponge back into the container filled with cleaning fluid. The rinsing step contaminates the cleaning fluid with waste liquid and the cleaning fluid becomes more contaminated each time the mop or sponge is rinsed. As a result, the effectiveness of the cleaning fluid deteriorates as more of the floor surface area is cleaned.

Some manual floor cleaning devices have a handle with a cleaning fluid supply container supported on the handle and a scrubbing sponge at one end of the handle. These devices include a cleaning fluid dispensing nozzle supported on the handle for spraying cleaning fluid onto the floor. These devices also include a mechanical device for wringing waste liquid out of the scrubbing sponge and into a waste container.

Manual methods of cleaning floors can be labor intensive and time consuming. Thus, in many large buildings, such as hospitals, large retail stores, cafeterias, and the like, floors are wet cleaned on a daily or nightly basis. Industrial floor cleaning “robots” capable of wet cleaning floors have been developed. To implement wet cleaning techniques required in large industrial areas, these robots are typically large, costly, and complex. These robots have a drive assembly that provides a motive force to autonomously move the wet cleaning device along a cleaning path. However, because these industrial-sized wet cleaning devices weigh hundreds of pounds, these devices are usually attended by an operator. For example, an operator can turn off the device and, thus, avoid significant damage that can arise in the event of a sensor failure or an unanticipated control variable. As another example, an operator can assist in moving the wet cleaning device to physically escape or navigate among confined areas or obstacles.

SUMMARY

One aspect of the disclosure provides a mobile surface cleaning robot that includes a robot body having a forward drive direction, a drive system supporting the robot body above a floor surface for maneuvering the robot across the floor surface, and a robot controller in communication with the drive system. The robot also includes a collection volume supported by the robot body and a cleaning module releasably supported by the robot body and arranged to clean the floor surface. The cleaning module includes a first vacuum squeegee having a first duct, a driven roller brush rotatably supported rearward of the first vacuum squeegee, a second vacuum squeegee disposed rearward of the roller brush and having a second duct, and a third duct in fluid communication with the first and second ducts. The third duct is connectable to the collection volume at a fluid-tight interface formed by selectively engaging the cartridge with the robot body.

In some implementations, the robot includes a liquid applicator supported by the robot body rearward of the second vacuum squeegee, the liquid applicator dispensing fluid on to the floor surface. A smearing element arranged to receive fluid dispensed by the liquid applicator may smear the received fluid onto the floor surface. The smearing element may define a lumen arranged to receive fluid dispensed by the liquid applicator. The smearing element may absorb the fluid received inside the lumen for application to the floor surface. The fluid retained by the fluid accumulator may be pressurized for forced distribution through the smearing element. Additionally or alternatively, the fluid retained by the fluid accumulator is gravity fed through the smearing element. In some examples, the smearing element is defined by a permeable material that draws the fluid from the fluid accumulator to the floor surface. In additional examples, the smearing element is defined by a plurality of bristles extending between the fluid accumulator and the floor surface. The plurality of bristles directs the fluid form the fluid accumulator to the floor surface through capillary action. The fluid accumulator may extend along the length of the smearing element.

The robot may include a detent mechanism for selectively engaging and disengaging the cleaning cartridge from the robot body. In some implementations, an engagement element allows selective engagement of the cleaning cartridge with the robot body. The engagement element provides audible and/or physical verification of successful engagement. The robot may include one or more guide connectors disposed on the cleaning module for releasably securing the cleaning module to the robot body. Each guide connector is receivable by a corresponding receptacle defined by the robot body for guiding and orienting the cleaning module during attachment of the cleaning module to the robot body.

The cleaning module may include a suspension supporting the second vacuum squeegee and biasing the second vacuum squeegee toward the floor surface (e.g., with a downward force of between about 1 Newton and about 5 Newtons). The robot may weigh between about 40 Newtons and about 50 Newtons when the collection volume is empty and between about 50 Newtons and about 60 Newtons when the collection volume is full of water.

In some implementations, the drive system comprises right and left driven wheel modules disposed substantially opposed along a transverse axis defined by the robot body. Each wheel module has a drive motor coupled to a respective wheel. Moreover, the robot body may movable secure each wheel module, which is spring biased downward away from the robot body with a biasing force of about 10 Newtons in a deployed position and about 20 Newtons in a retracted position. The drive system may include a caster wheel disposed on a forward portion of the robot body. The caster wheel can be arranged to support between 0 and about 10% of the weight of the robot. In some examples, the drive system includes right and left non-driven wheels disposed rearward of the right and left driven wheel modules. The right and left non-driven wheels can be arranged to support between 0 and about 10% of the weight of the robot.

In yet another aspect, a method of operating a mobile surface cleaning robot includes blowing air onto a floor surface beneath the robot, lifting substantially dry debris from the floor surface into a first duct, dispensing fluid onto the floor surface, lifting at least one of fluid or wet debris from the floor surface into a second duct, and moving a flow debris from the first duct and a flow of the at least one of fluid or wet debris from the second duct both through a third duct into a collection volume.

In some implementations, the method includes allowing an expansion of air in the collection volume to allow debris to settle into the collection volume. The method may include evacuating air from the collection volume. When blowing air onto the floor surface, the method may include blowing the air from opposite directions toward the first duct centrally located on the robot.

The method may include dispensing the fluid onto the floor surface rearward of blowing air onto the floor surface and rearward of lifting the substantially dry debris from the floor surface and/or dispensing the fluid onto the floor surface rearward lifting the at least one of fluid or wet debris from the floor surface. The method may include smearing the dispensed fluid onto the floor surface. Moreover, the method may include filtering the evacuated air from the collection bin.

One aspect of the disclosure provides a mobile surface cleaning robot that includes a robot body having a forward drive direction and a drive system supporting the robot body above a floor surface for maneuvering the robot across the floor surface. The robot also includes a wet cleaning system supported by the robot body and arranged to clean the floor surface and a robot controller in communication with at least one of the drive system and the cleaning system. The cleaning system includes a liquid collection volume defining at least one orifice and an anti-spill device in communication with the robot controller. The robot controller causes the anti-spill device to open and close the at least one orifice based on a robot state (e.g., at least one of a drive state, a cleaning state, a servicing state (removal of collection volume), a wheel-drop state, and a tip state).

In some implementations, the anti-spill device includes at least one orifice sealer moving between an open position and a closed position for opening and closing the corresponding at least one orifice. The anti-spill device may include an actuator shaft moving longitudinally through an aperture defined by the liquid collection volume. The actuator shaft causes movement of the at least one orifice sealer between its open and closed positions.

The anti-spill device may include an orifice sealer opener disposed outside of the collection volume. The orifice sealer opener may include a rotary motor having a motor shaft, a cam coupled to the motor shaft, and an actuator shaft supported to slide longitudinally and spring biased to abut the cam. Rotation of the cam moves the actuator shaft longitudinally between open and closed positions. The actuator shaft moves into an aperture defined by the liquid collection volume when moving to its open position and moves out of the aperture defined by the liquid collection volume when moving to its closed position. In some examples, the anti-spill device includes an actuator receiver disposed inside the collection volume. The actuator receiver may include a receiver shaft supported to slide longitudinally and arranged to receive engagement of the actuator shaft. The receiver shaft moves between open and closed positions and is spring biased toward its closed position. A lever arm engages the receiver shaft and is attached to the at least one orifice sealer. The receiving shaft moves the lever moving between corresponding open and closed positions.

In some implementations, removal of the liquid collection volume from the robot body causes the actuator shaft to disengage from the spring biased receiver shaft. The unengaged receiver shaft moves to its closed position, moving the lever arm and the at least one orifice sealer to their corresponding closed positions, closing the at least one orifice of the liquid collection volume.

The robot controller may issue a command to the anti-spill device to close the at least one orifice of the liquid collection volume when the cleaning system ceases a cleaning operation. Moreover, the robot controller may issue a command to the anti-spill device to open the at least one orifice of the liquid collection volume when the cleaning system executes a cleaning operation. In additional implementations, the robot controller issues a command to the anti-spill device to close the at least one orifice of the liquid collection volume in response to receiving a sensor signal indicating at least one of a wheel drop condition, a cliff detection, and robot removal from the floor surface. Additionally or alternatively, the anti-spill device may close the at least one orifice of the liquid collection volume in response to removal of the collection volume from the robot body.

Another aspect of the disclosure provides a method of operating a mobile surface cleaning robot. The method includes detecting an operating state of the robot and in response to detecting a cleaning state of the robot, moving an orifice sealer of an orifice of a collection volume of the robot to an open position, allowing a flow of fluid through the orifice. The method further includes, in response to detecting a non-cleaning state of the robot, moving the orifice sealer to a closed position, preventing any flow of fluid through the orifice.

In some implementations, the method includes detecting the cleaning state by receiving a signal indicating execution of a cleaning operation. The method may include detecting the non-cleaning state by receiving a signal indicating at least one of cessation of the cleaning operation, a wheel drop condition, a cliff detection, robot removal from a floor surface, or detachment of the collection volume from the robot. Moreover, the non-cleaning state can be detected by receiving a first signal indicating attachment of the collection volume to the robot in combination with a second signal indicating non-execution of a cleaning operation.

In some examples, the method includes moving an actuator shaft longitudinally between open and closed positions through an aperture defined by the collection volume. The actuator shaft causes movement of the orifice sealer between its corresponding open and closed positions. The method may also include rotating a cam that moves the actuator shaft longitudinally between open and closed positions, causing corresponding movement of the orifice sealer between its open and closed positions. The method sometimes includes allowing spring biased movement of the orifice sealer to its close position upon movement of the actuator shaft to its closed position.

DETAILED DESCRIPTION

A mobile autonomous robot can clean while traversing a surface. The robot can remove wet debris from the surface by agitating the debris and/or wet clean the surface by applying a cleaning liquid to the surface, spreading (e.g., smearing, scrubbing) the cleaning liquid on the surface, and collecting the waste (e.g., substantially all of the cleaning liquid and debris mixed therein) from the surface.

Referring toFIGS. 1-3, in some implementations, a robot100includes a body110supported by a drive system120that can maneuver the robot100across the floor surface10based on a drive command having x, y, and θ components, for example. The robot body110has a forward portion112and a rearward portion114. The drive system120includes right and left driven wheel modules120a,120b. The wheel modules120a,120bare substantially opposed along a transverse axis X defined by the body110and include respective drive motors122a,122bdriving respective wheels124a,124b. The drive motors122a,122bmay releasably connect to the body110(e.g., via fasteners or tool-less connections) with the drive motors122a,122boptionally positioned substantially over the respective wheels124a,124b. The wheel modules120a,120bcan be releasably attached to the chassis110and forced into engagement with the floor surface10by respective springs. The robot100may include a caster wheel126disposed to support a forward portion112of the robot body110. The robot body110supports a power source102(e.g., a battery) for powering any electrical components of the robot100.

In some examples, the wheel modules120a,120bare movable secured (e.g., rotatably attach) to the robot body110and receive spring biasing (e.g., between about 5 and 25 Newtons) that biases the drive wheels124a,124bdownward and away from the robot body110. For example, the drive wheels124a,124bmay receive a downward bias about 10 Newtons when moved to a deployed position and about 20 Newtons when moved to a retracted position into the robot body110. The spring biasing allows the drive wheels to maintain contact and traction with the floor surface10while any cleaning elements of the robot100contact the floor surface10as well.

The robot100can move across the floor surface10through various combinations of movements relative to three mutually perpendicular axes defined by the body110: a transverse axis X, a fore-aft axis Y, and a central vertical axis Z. A forward drive direction along the fore-aft axis Y is designated F (sometimes referred to hereinafter as “forward”), and an aft drive direction along the fore-aft axis Y is designated A (sometimes referred to hereinafter as “rearward”). The transverse axis X extends between a right side R and a left side L of the robot100substantially along an axis defined by center points of the wheel modules120a,120b.

Referring toFIG. 2, in some implementations, the robot100weighs about 40-50 N empty, and 50-60 N when full of water. The robot100may have a center of gravity CG between 0 and 20 mm forward of the transverse axis X (a centerline connecting the drive wheels124a,124b). The robot100may rely on having most of its weight over the drive wheels124a,124bto ensure good traction and mobility on wet surfaces10. Mover, the caster126disposed on the forward portion112of the robot body110can support between about 0-10% of the robot's weight. The robot100may include one or more non-driven wheels, such as right and left non-driven wheel128a,128brotatably supported by the robot body110rearward of the drive wheels124a,124bfor supporting between about 0-10% of the robot's weight and for ensuring the rearward portion114of the robot100doesn't sit on the ground when accelerating or when water is sloshing around.

A forward portion112of the body110carries a bumper130, which detects (e.g., via one or more sensors) one or more events in a drive path of the robot100, for example, as the wheel modules120a,120bpropel the robot100across the floor surface10during a cleaning routine. The robot100may respond to events (e.g., obstacles, cliffs, walls) detected by the bumper130by controlling the wheel modules120a,120bto maneuver the robot100in response to the event (e.g., away from an obstacle). While some sensors are described herein as being arranged on the bumper, these sensors can be additionally or alternatively arranged at any of various different positions on the robot100.

A user interface140disposed on a top portion of the body110receives one or more user commands and/or displays a status of the robot100. The user interface140is in communication with the robot controller150carried by the robot100such that one or more commands received by the user interface140can initiate execution of a cleaning routine by the robot100.

The robot controller150(executing a control system) may execute behaviors that cause the robot100to take an action, such as maneuvering in a wall following manner, a floor scrubbing manner, or changing its direction of travel when an obstacle is detected (e.g., by the bumper sensor system400). The robot controller150can maneuver the robot100in any direction across the floor surface10by independently controlling the rotational speed and direction of each wheel module120a,120b. For example, the robot controller150can maneuver the robot100in the forward F, reverse (aft) A, right R, and left L directions. As the robot100moves substantially along the fore-aft axis Y, the robot100can make repeated alternating right and left turns such that the robot100rotates back and forth around the center vertical axis Z (hereinafter referred to as a wiggle motion). The wiggle motion can allow the robot100to operate as a scrubber during cleaning operation. Moreover, the wiggle motion can be used by the robot controller150to detect robot stasis. Additionally or alternatively, the robot controller150can maneuver the robot100to rotate substantially in place such that the robot100can maneuver out of a corner or away from an obstacle, for example. The robot controller150may direct the robot100over a substantially random (e.g., pseudo-random) path while traversing the floor surface10. The robot controller150can be responsive to one or more sensors (e.g., bump, proximity, wall, stasis, and cliff sensors) disposed about the robot100. The robot controller150can redirect the wheel modules120a,120bin response to signals received from the sensors, causing the robot100to avoid obstacles and clutter while treating the floor surface10. If the robot100becomes stuck or entangled during use, the robot controller150may direct the wheel modules120a,120bthrough a series of escape behaviors so that the robot100can escape and resume normal cleaning operations.

Referring toFIGS. 2-5B, in some implementations, the robot100includes a cleaning system160having a wet cleaning subsystem200and/or a dry cleaning subsystem300. The wet and dry subsystems200,300may operate together or independently. When operating together the two subsystems200,300share one or more components, such as passageways or a collection bin. In the examples shown, the two subsystems200,300share one or more components, allowing a lower manufacturing cost and fewer components for servicing.

The wet cleaning subsystem200has a liquid volume cartridge202disposed on the chassis110. In some implementations, the liquid volume202is configured as a removable cartridge received by the chassis110. The liquid volume cartridge202includes a supply volume202aand a collection volume202b, for storing clean fluid and waste fluid, respectively. The supply and collection volumes may be of the same or difference sizes. For example, the collection volume202bmay be larger than the supply volume202a(e.g., by greater than 20%) to accommodate collected debris.

In use, a user opens a supply port204adisposed the supply volume202aand pours cleaning fluid into the supply port204ain fluid communication with the supply volume202a. After adding cleaning fluid to the robot100, the user then closes the supply port204a(e.g., by tightening a cap over a threaded mouth). The user then sets the robot100on the surface10to be cleaned and initiates cleaning by entering one or more commands on the user interface140.

In some implementations, the supply volume202aand the collection volume202bare configured to maintain a substantially constant center of gravity along the transverse axis X while at least 25% of the total volume of the robot100shifts from cleaning liquid in the supply volume202ato waste in the collection volume202bas cleaning liquid is dispensed from the supply volume202aonto the floor surface10and then collected as waste with debris in the collection volume202b. In the example shown, the supply and collection volumes202a,202bextend along the transverse axis X in substantially equal overlapping extents (e.g., by defining substantially crescent shapes side-by-side).

In some implementations, all or a portion of the supply volume202ais a flexible bladder within the collection volume202band surrounded by the waste collection volume202bsuch that the bladder compresses as cleaning liquid exits the bladder and waste filling the collection volume202btakes place of the cleaning liquid that has exited the bladder. Such a system can be a self-regulating system which can keep the center of gravity of the robot100substantially in place (e.g., over the transverse axis X). For example, at the start of a cleaning routine, the bladder can be full such that the bladder is expanded to substantially fill the collection volume202b. As cleaning liquid is dispensed from the robot100, the volume of the bladder decreases such that waste entering the collection volume202breplaces the displaced cleaning fluid that has exited the flexible bladder. Toward the end of the cleaning routine, the flexible bladder is substantially collapsed within the collection volume202band the collection volume202bis substantially full of waste.

In the example shown, the supply volume202aand the collection volume202bare defined by substantially crescent or tear drop shaped tanks or compartments arranged side-by-side along the transverse axis X. Other configurations are possible as well, such as stacked compartments (e.g., partially or fully stacked on top of one another), concentric compartments (concentric such that one is inside the other in the lateral direction), interleaved compartments (e.g., interleaved L shapes or fingers in the lateral direction), and so on.

The robot100may include a detent mechanism216for selectively engaging and disengaging the liquid volume cartridge202from the robot body110. In some implementations, an engagement element218allows selective engagement of the cleaning cartridge180with the robot body110. The engagement element218and/or detent may provide audible and/or physical verification of successful engagement.

FIG. 6Adepicts a perspective view of an exemplary liquid volume cartridge202having an active anti-spill device210that prevents unwanted spillage from the collection volume202bof dirty fluid collected from the floor surface10when removing the collection volume202bfrom the robot100(e.g., for emptying). In the example shown, the collection volume202bis defined by a collection volume202bdefining at least one orifice220for the flow of fluid into and/or out of the collection volume202b. The collection volume202bmay be removable from the robot100, as shown; however, the collection volume202bcan also be integral with the robot body110.

Referring toFIGS. 6A-6D, in some implementations, the anti-spill device210includes at least one orifice sealer230(e.g., a door) that is spring biased to move from an open position that allows fluid to flow through the at least one orifice220to a closed position that seals closed the at least one orifice220. When the collection volume202bis attached to the robot body110in an engaged position, the anti-spill device210opens the at least one orifice sealer230and allows fluid to flow through the at least one orifice220. When the collection volume202bis removed from the robot body110to a disengaged position, the anti-spill device210causes the at least one orifice sealer230to close and seal the at least one orifice220, preventing or inhibiting escapement of fluid and/or debris from the collection volume202b.

In the example shown, the collection volume202bhas first and second orifices220a,220b. When the collection volume202bis attached to the robot body110, in the engaged position, the first orifice220ais in fluid communication with a wet vacuum squeegee206band the second orifice220bis in fluid communication with an air mover190. The anti-spill device210includes first and second orifice sealers230a,230bconfigured to cover and seal the first and second orifices220a,220b, respectively, when the collection volume202bis removed from the robot100(i.e., in the disengaged position). Each orifice sealer230,230a-bis spring biased to move from an open position to a closed position over a respective orifice220,220a-bof the collection volume202b. The orifice sealer(s)230,230a-bmay be pivotally coupled to an inner surface221of the collection volume202badjacent their respective orifices220,220a-b.

Although the example shown illustrates a collection volume202bwith two orifices220,220a-band an anti-spill device210with two orifice sealers230,230a-bthat seal both orifices220,220a-bwhen the collection volume202bis removed from the robot body110, other examples are possible as well. For example, the anti-spill device210may close and seal one or more orifices220of the collection volume202busing a single orifice sealer230.

In some implementations, the anti-spill device210includes an orifice opener240that moves at least one orifice sealer230from the closed position to the open position when the collection volume202bis attached to the robot body110. In the example shown, the orifice opener240is actuated by an actuator250, such as a linear or a rotary actuator. The orifice opener actuator250may be a motor driven linkage system, a solenoid, a lever, etc. The orifice opener240is shown attached to an inner surface221of the collection volume202band the orifice opener actuator250is shown attached to the an outer surface223of the collection volume202b; however, both the orifice opener240and the orifice opener actuator250may be disposed inside in the collection volume202b(e.g., for having the anti-spill device210entirely contained within the collection volume202b).

In some examples, the orifice opener actuator250includes a housing252that houses and supports a rotary motor254having a rotating motor shaft256coupled to a cam258, which engages and abuts a linear actuator shaft260supported to slide longitudinally (i.e., along its longitudinal axis). The cam258rotates about a rotational axis255of the rotary motor254between an open position and a closed position. The cam258may also have intermediate positions (i.e., for partially open/closed states) as well. The actuator shaft260is supported to slide along its longitudinal axis261between corresponding open and closed positions. A return spring264, which may be compressed between the actuator housing252and a spring catch262(e.g., an arm) of the actuator shaft260, biases the actuator shaft260against the cam258. Therefore, as the cam258rotates between its open and closed positions, the actuator shaft260moves linearly between its corresponding open and closed positions.

A position sensor270may detect movement of the cam258and/or the actuator shaft260between their open and closed positions. The position sensor270includes a first magnetic sensor that detects movement of the cam258to its open position and second magnetic sensor that detects movement of the cam258to its closed position. In some examples, the position sensor270includes a magnet attached to the actuator shaft260and a magnetic sensor arranged (e.g., parallel to the shaft) to detect movement of the actuator shaft260between its open and closed positions. Additionally or alternatively, the position sensor includes a magnet attached to the cam258and a magnetic sensor arranged (e.g., perpendicular to the axis of rotation of the cam) to detect movement of the cam258between its open and closed positions.

The actuator shaft260extends from the actuator housing252and passes through a shaft hole224defined by the collection volume202b, which may be sealed about the actuator shaft260. The actuator shaft260is received by the orifice opener240, which moves the orifice sealer(s)230between their open and closed positions. The orifice opener240may include a housing242that defines a shaft hole244for receiving the actuator shaft260. The orifice opener housing242houses and slidably supports a receiver shaft280to slide longitudinally (i.e., along its longitudinal axis) and be aligned to receive engagement of the actuator shaft260. As the actuator shaft260moves from its closed position to it open position, it engages and moves the receiver shaft280from its closed position to its open position. The receiver shaft280is spring biased toward its closed position. For example, a spring284compressed between the orifice opener housing242and a spring catch282(e.g., an arm) of the receiver shaft280biases the receiver shaft280toward its closed position. The receiver shaft280(e.g., an arm thereon) engages a lever arm246, which is pivotally supported by the orifice opener housing242. Each orifice sealer230is coupled to the lever arm232. Movement of the receiver shaft280between its open closed positions rotates the lever arm246(e.g., via a shaft arm286) as well as the coupled orifice sealer(s)230between their open and closed positions, respectively.

In some examples, the active anti-spill device210receives commands for opening and closing the orifice sealer(s)230from the robot controller150or a dedicated anti-spill controller290(e.g., having a computing process and memory), which communicates with the robot controller150.

When the robot100is not actively cleaning, the tank orifices220of the collection volume202bcan be closed. The robot controller150may issue a command to the anti-spill device210to move the orifice sealer(s)230to its/their closed position. The rotary motor254moves the cam258to its closed position (as sensed by the position sensor270), which moves the actuator shaft260, receiving shaft280, lever arm246, and orifice sealer(s)230all to their closed positions, causing the orifice sealer(s)230to seal over its/their respective orifice(s)220, preventing or inhibiting fluid flow therethrough. In the example shown, when the first and second orifice sealer(s)230a-bare in their closed positions, they seal closed the first and second orifices220a-b, respectively, preventing the flow of air and fluid therethrough.

Once the robot100begins a cleaning operation, the orifices220,220a-bof the collection volume202bmay be open to allow the flow of air into and out of the collection volume202band dirty fluid into the collection volume202b. When the robot100begins a cleaning operation, the robot controller150issues a command to the anti-spill device210causing opening of the orifice sealer(s)230,230a-b, which opens the orifices220,220a-b. The rotary motor254moves the cam258to its open position (as sensed by the position sensor270), which moves the actuator shaft260, receiving shaft280, lever arm246, and orifice sealer(s)230,230a-ball to their open positions. With the orifice opener actuator250in its open state, the return spring284between the orifice opener housing242and the spring catch282of the receiver shaft280is compressed, biasing the receiver shaft280for movement to its closed position once it is no longer held in its open position by the actuator shaft260. Once the robot100completes the cleaning operation, the orifices220,220a-bof collection volume202bmay be closed again. The robot controller150may issue a command to the anti-spill device210to move the orifice sealer(s)230,230a-bto its/their closed position again.

During a cleaning operation, if the robot controller150receives a sensor signal indicating a wheel drop condition or other signal that the robot100is lifted off the floor surface10or begins to fall, the robot controller150may issue a command to the anti-spill device210to close the orifices220,220a-bof the collection volume202b. If the collection volume202bis removable from the robot body110and is removed when the tank orifices220,220a-bare open, the robot controller150may receive a signal from a collection volume removal sensor (e.g., contact sensor, switch, proximity sensor, etc.) indicating removal of the collection volume. In response, the robot controller150may issue a command to the anti-spill device210to close the orifices220,220a-bof the collection volume202b. In some examples, as the collection volume202bis removed from the robot body110, the actuator shaft260slides out of the collection volume202band orifice opener housing242, disengaging from the receiver shaft280. The compressed return spring284extends, maintaining contact between the actuator shaft260and the receiver shaft280until the receiver shaft280is in the closed position. The receiver shaft280rotates the lever arm246, moving the orifice sealer(s)230,230a-bto their closed positions, closing the tank orifices220,220a-b. The return spring284presses against the receiver shaft280causing compression of the orifice sealer(s)230,230a-b, via the lever arm246, against the inner surface221of the collection volume202b. Although the orifice sealers230are shown as pivoting between their open and closed positions, they can also move linearly or along any other path of movement.

After all of the cleaning fluid has been dispensed from the robot100(e.g., form the supply volume202a), the robot controller150may stop movement of the robot100and provide an alert (e.g., a visual alert or an audible alert) to the user via the user interface140. The user can then open a port166defined by the collection volume202bto remove collected waste therein.

The liquid volume cartridge202isolates substantially the entire electrical system of the robot100from carried fluid. Examples of sealing that can be used to separate electrical components of the robot100from the cleaning liquid and/or waste include application of the super-hydrophobic coating or treatment, covers, plastic or resin modules, potting, shrink fit, gaskets, or the like. Any and all elements described herein as a circuit board, PCB, detector, or sensor can be sealed using the super-hydrophobic coating or treatment or any of various different methods. Moreover, electrical components and/or components in intermediate contact with electrical components can receive the super-hydrophobic coating or treatment to prevent conveyance of fluid to the electrical components.

Referring toFIGS. 6E-6H, in some implementations, the anti-spill device210includes at least one orifice sealer230,230a-b(e.g., a door) that is spring biased (e.g., by a spring284) to move from an open position that allows fluid to flow through the at least one orifice220,220a-bto a closed position that seals closed the at least one orifice220,220a-b. In the example shown, the anti-spill device210includes first and second orifice sealers230a,230bthat each pivot at a proximal end231between the open and closed positions. A frame212may support the orifice sealers230a,230bat their proximal ends231and optionally engage the springs284. The frame212may support a filter214and/or be configured to direct liquid away from the port166. This can prevent dirty liquid from being sucked out of the collection volume202bduring operation.

When the liquid volume cartridge202is attached to the robot body110in an engaged position, a protrusion234(e.g., disposed on the robot body110) opens the orifice sealer230,230a-band allows fluid to flow through the corresponding orifice220. When the liquid volume cartridge202is removed from the robot body110to a disengaged position, the anti-spill device210causes the orifice sealer(s)230,230a-bto close (e.g., via spring bias) and seal the corresponding orifice(s)220,220a-b, preventing or inhibiting escapement of fluid and/or debris from the collection volume202b.

Referring toFIG. 6H, in some examples, the liquid volume cartridge202includes the pump172, which may include a snorkel171arranged to suck liquid from a top portion of the supply volume202a, since the cleanest liquid typically is at the top, while dirt generally settles toward the bottom.

Referring toFIGS. 2-5Band7A-7B, the wet cleaning system160may include a fluid applicator170ain fluid communication with the supply volume202aand carried by the robot body110rearward of the dry cleaning subsystem300. The fluid applicator170aextends along the transverse axis X and dispenses cleaning liquid12onto the surface10during wet vacuuming rearward of any vacuuming components to allow the dispensed fluid to dwell on the floor surface10. As the robot100maneuvers about the floor surface10, a vacuum assembly sucks up previously dispensed liquid and debris suspended therein. A pump172forces cleaning liquid through the fluid applicator170aand out of a fluid disperser174defined by or disposed on the fluid applicator170a. The fluid disperser174may be a series of orifices174a, as shown inFIGS. 2,7A, and B, spaced substantially equidistantly along the applicator170ato produce a substantially uniform spray pattern of cleaning liquid onto the floor surface10.

Additionally or alternatively, the fluid disperser174may be configured as an accumulator174bto direct a flow of liquid12onto and/or into a smearing element176of the fluid applicator170a. In the example shown inFIG. 7D, the fluid accumulator174bengages with the smearing element176to form an accumulator volume173in which fluid12accumulates. The fluid12is pumped from the supply volume202aand delivered to the accumulator174bby one or more lumens177. The accumulator174bmay be formed as a clip (e.g., out of sheet metal or plastic) that pinches down on the smearing element176. In the example shown, the accumulator174bhas a sidewall175angled downward toward the smearing element176at angle of about 45 degrees to increase the contact area between the smearing element176and fluid12accumulated within the accumulator volume173. The angled sidewall175further assists with directing the fluid12into the smearing element176. As a fluid volume builds up within the accumulator174b, fluid12escapes through the smearing element176. The accumulator174btherefore retains pressurized fluid12in direct contact with a top portion of the smearing element176disposed within the accumulator volume173, thereby causing fluid12to flow into the smearing element176. The fluid12flows through the smearing element for deposition on the floor surface10under the force(s) of pressure, gravity and/or capillary action, and the smearing element176wicks, absorbs, or accumulates fluid12for application onto the floor surface10.

Referring toFIGS. 7A-7F, in some implementations, the fluid applicator170aincludes a smearing element176, such as bristle brush176a(FIG. 7E) or continuous element176b(FIG. 7F) (e.g., a sponge or a microfiber cloth) that directs fluid12onto the floor surface12via capillary action. The smearing element176smears or applies a dispensed fluid12on the floor surface10. leaving a smooth sheen or film14of fluid12. The smearing element176may extend along substantially an entire width of the robot100(along the X axis) or a portion thereof rearward of the drive wheel modules120a,120b, an entire length of the fluid applicator170a, or only a portion of the fluid applicator170a.

In one example shown inFIG. 7A, the smearing element176is arranged (e.g., below the fluid disperser174a) such that the fluid applicator170adispenses fluid12forward of and/or onto the smearing element176, which absorbs the fluid12and smears it onto the floor surface10. Additionally or alternatively, the fluid disperser174amay define a lumen177(e.g., therethrough or partially therethrough) in fluid communication with the supply volume202a, as shown inFIG. 7B. As the lumen177receives fluid12, the smearing element176absorbs the fluid12and/or allows the fluid12to pass to its outer surface178for application onto the floor surface10. The smearing element176may provide relatively more even fluid dispersion onto the floor surface10compared to fluid application directly onto the floor surface10alone from the fluid dispenser174a. Moreover, the smearing element176can agitate or scrub the floor surface10, as the robot100moves over the floor surface10.

Referring toFIGS. 7C and 7D, in some implementations, the cleaning system160includes a squeegee-fluid applicator module170b, which includes the smearing element176, the accumulator174band a wet vacuum squeegee206b. The robot100pumps fluid12in to the accumulator volume173of squeegee-fluid applicator module170bthrough the one or more lumens177. The fluid12travels the length of the smearing element176within the accumulator volume173defined by the accumulator174band the smearing element176held therein. For example, in bristled brush implementations of the smearing element176, the accumulator174bpinches the bristles together tightly so that the fluid12entering the accumulator volume173travels along the length of the smearing element176rather than immediately flowing between the bristles and onto a surface below the smearing element176. Once the accumulator174bis filled with fluid12, pressure increases within the accumulator174band the fluid12therein starts being forced out of the accumulator volume173and into the bristles of the smearing element176. The smearing element176is uniformly wetted along its length and therefore deposits a smooth sheen of water on the floor, which leads to even cleaning and prevents streaking.

In the example shown, the smearing element176is disposed rearward of the wet vacuum squeegee206b, with respect to the forward drive direction F, so that fluid dispersed on the floor surface10may have a dwell time before being picked up again by the cleaning system160, if and when the robot100re-traverses that location of the floor surface10. The squeegee-fluid applicator module170bmay define one or more ports for delivering fluid and one or more ports for returning collected debris. In the example shown, the squeegee-fluid applicator module170bincludes one or more fluid lumens177that receive fluid12into the accumulator174band one or more vacuum ports179for guiding a flow of evacuated fluid and/or debris from the wet vacuum squeegee206bout of the squeegee-fluid applicator module170b. The vacuum port(s)179connect(s) to a cleaning cartridge180.

The wet vacuum squeegee206bmay include first and second squeegee blades205a,205barranged to gather or collect dwelled fluid12and/or debris therebetween for evacuation off of the floor surface10. The squeegee blades205a,205bmay be arranged parallel or non-parallel to one another and to the smearing element176. Moreover, the squeegee blades205a,205bmay be linear, curvilinear, or define some other shape conducive for evacuating fluid12and/or debris off of the floor surface10.

Referring again toFIGS. 2-5B, in some implementations, the cleaning cartridge180carried by the robot100lifts waste from the floor surface10and into the collection volume202bof the robot100, leaving behind a wet vacuumed floor surface10. The cleaning cartridge180includes components of both the wet cleaning subsystem200and the dry cleaning subsystem300. The wet cleaning system200may include a wet vacuum squeegee206bdisposed on the cleaning cartridge180or the robot body110forward of the fluid applicator170aand extend from the bottom surface116of the robot body110to movably contact the floor surface10. The wet vacuum squeegee206bmay be positioned forward or rearward of the wheel modules120a,120b. A rearward positioning of the wet vacuum squeegee206bcan reduce rearward tipping of the robot100in response to thrust created by the wheel modules120a,120bpropelling the robot100in a forward direction. The movable contact between the wet vacuum squeegee206band floor surface10acts to lift waste (e.g., a mixture of cleaning liquid and debris) from the floor surface10as the robot100is propelled in the forward direction.

In the examples shown, the wet cleaning system200includes dry and wet vacuum squeegees206a,206bin fluid communication via ducting208with an air mover190(e.g., fan) and the collection volume202b. The air mover190creates a low pressure region along its fluid communication path including the collection volume202band the vacuum squeegees206a,206b. The air mover190creates a pressure differential across the vacuum squeegees206a,206b, resulting in suction of waste from the floor surface10and through the dry and wet vacuum squeegees206a,206b. The dry and wet vacuum squeegees206a,206bare disposed on the cleaning cartridge180with the first vacuum squeegee206aforward of the second vacuum squeegee206b. In some examples, the dry vacuum squeegee206ais disposed on forward portion112of the robot body110, while the wet vacuum squeegee206bis disposed on rearward portion114of the robot body110.

In the examples shown, the wet cleaning system200includes first and second ducts208a,208bin fluid communication with the dry and wet vacuum squeegees206a,206b, respectively. The two conduits208a,208bmerge to form a common conduit208cthat is in fluid communication with the air mover190and the collection volume202b. The dry vacuum squeegee206amay include first and second blowers207a,207bdisposed opposite each other and arranged to move debris to first duct208acentrally located along the dry vacuum squeegee206a. A spring biased suspension209may support the wet vacuum squeegee206band apply a downward force (e.g., between about 1 and 5 Newtons) that ensures contact between the wet vacuum squeegee206band the floor surface10without creating excess frictional drag. The dry vacuum squeegee206aand corresponding duct208areceive a flow of primarily dirty air, while the wet vacuum squeegee206band corresponding duct208breceive a flow of primarily dirty water.

The robot100may include a dry cleaning system300having a roller brush310(e.g., with bristles and/or beater flaps) extending parallel to the transverse axis X and rotatably supported by the cleaning cartridge180(or, alternatively, the robot body110) to contact the floor surface10rearward of the dry vacuum squeegee206aand forward of the wet vacuum squeegee206bof the wet cleaning system200. The roller brush310may be driven by a corresponding brush motor312or by one of the wheel drive motors122a,122b(e.g., using a gearbox314). The driven roller brush310agitates debris (and applied fluid) on the floor surface10, moving the debris into a suction path of at least one of the vacuum squeegees206a,206b(e.g., a vacuum or low pressure zone) for evacuation to the collection volume202b. Additionally or alternatively, the driven roller brush310may move the agitated debris off the floor surface10and into a collection bin (not shown) adjacent the roller brush310or into one of the ducting208. The roller brush310may rotate so that the resultant force on the floor10pushes the robot100forward.

Referring toFIGS. 2-5Band8, in some implementations, the cleaning system160combines wet and dry debris flows into a single common passageway or conduit208cin fluid communication with an inlet or orifice220bof the collection volume202b, allowing the dry, solid debris to be deposited in the same collection volume202bas the liquid debris. By combining the flows before they enter the collection volume202b, the air can expand and slow inside the collection volume202bwhich causes the debris to fall out of the flow(s), before sucking the air out of the collection volume202bthrough an outlet or orifice220ausing the air mover190. The outlet orifice220ais behind a filter222, which prevents debris from being sucked into the air mover190. Moreover, the orifices220may have features that prevent water from sloshing out of the collection volume202bwhen the robot accelerates or decelerates.

Rather than collecting the dirty water in one collection volume and the dry debris in another separate filtered collection volume, all dirt (wet or dry) is collected in one place, the collection volume202b, and therefore the only clean up requirement is to dump the collection volume202b/tank. Since dry debris can float around in the collection volume202b, an emptying port204bof the collection volume202bcan be sized and configured to allow easy draining of all captured debris.

As the cleaning cartridge180suctions wet and dry debris from the floor surface10, wetness may allow dirt and debris to adhere to walls of the cleaning cartridge180. The cleaning cartridge180may releasable connect to the robot body110and/or the cleaning system160to allow removal by the user to clean any accumulated dirt or debris from within the cleaning cartridge180. Rather than requiring significant disassembly of the robot100for cleaning, a user can remove the cleaning cartridge180(e.g., by releasing tool-less connectors or fasteners) for rinsing in a sink. In some implementations, all of the cleaning head mechanisms and ducting are located within the single removable cleaning cartridge180, or cleaning cartridge, which can be removed in its entirety and rinsed out under a sink, making it very easy for the user to clean the dirtiest parts of the robot100. The removed cleaning cartridge180, or cleaning cartridge, presents the dirty water connection to the liquid volume cartridge202(also referred to as a tank), and it may be possible to clean the wet cleaning subsystem200by pouring water through the ports or orifices220, flushing out the system. In addition, the brush310and wet vacuum squeegee206bcan be removed from the cleaning cartridge180allowing the user to clean those independently as well.

A latching system182may allow both easy removal of the cleaning cartridge180, or vacuum module, from the robot100and easy attachment back onto the robot100by guiding the cleaning cartridge180for proper location during reassembly. The latching system182may include one or more guide connectors184disposed on the cleaning cartridge180that are received by and releasably connect to the robot body110. Locating receptacles118defined by the robot body110(or another portion of the robot100) receive the respective guide connectors184. When the user releases the guide connector(s)184, the cleaning cartridge180releases away from the robot body110for servicing. A latch may release all of the guide connectors184simultaneously. The user may reattach the cleaning cartridge180onto the robot by locating the guide connectors184in their respective receptacles118and pushing the cleaning cartridge180onto the robot100until secured (e.g., clicking into place with via the latching system182). Once secured, the latching system182holds the cleaning cartridge180firmly against any gaskets and/or conduit connections to form an air-tight and water-tight seal, preventing any leaking therefrom. The single common passageway or conduit208ctherefore forms a fluid-tight interface with the inlet or orifice220bof the collection volume202bwhen the cleaning cartridge180mates with the robot body110.

The cleaning cartridge180may include the rotating brush310of the dry cleaning sub-system300. The gearbox314driving the brush310may be disposed on the cleaning cartridge180and provide a geared interface316with the brush motor312disposed on the robot body110. When the cleaning cartridge180is removed, the brush motor312and electronics stay on the robot body110(away from water rinsing of the vacuum assembly180). When the cleaning cartridge180attaches to the robot body110, the guide connectors184properly orient and locate the gearbox314with the brush motor312so that the geared interface has properly engaged gears.

Referring toFIGS. 1-5Band9. to achieve reliable and robust autonomous movement, the robot100may include a sensor system500having several different types of sensors which can be used in conjunction with one another to create a perception of the robot's environment sufficient to allow the robot100to make intelligent decisions about actions to take in that environment. The sensor system500may include one or more types of sensors supported by the robot body110, which may include obstacle detection obstacle avoidance (ODOA) sensors, communication sensors, navigation sensors, etc. For example, these sensors may include, but not limited to, proximity sensors, contact sensors, a camera (e.g., volumetric point cloud imaging, three-dimensional (3D) imaging or depth map sensors, visible light camera and/or infrared camera), sonar, radar. LIDAR (Light Detection And Ranging, which can entail optical remote sensing that measures properties of scattered light to find range and/or other information of a distant target), LADAR (Laser Detection and Ranging), etc. In some implementations, the sensor system500includes ranging sonar sensors, proximity cliff detectors, contact sensors, a laser scanner, and/or an imaging sonar.

There are several challenges involved in placing sensors on a robotic platform. First, the sensors need to be placed such that they have maximum coverage of areas of interest around the robot100. Second, the sensors may need to be placed in such a way that the robot100itself causes an absolute minimum of occlusion to the sensors; in essence, the sensors cannot be placed such that they are “blinded” by the robot itself. Third, the placement and mounting of the sensors should not be intrusive to the rest of the industrial design of the platform. In terms of aesthetics, it can be assumed that a robot with sensors mounted inconspicuously is more “attractive” than otherwise. In terms of utility, sensors should be mounted in a manner so as not to interfere with normal robot operation (snagging on obstacles, etc.).

In some implementations, the sensor system500one or more proximity sensors410and bump or contact sensor420in communication with the robot controller150and arranged in one or more zones or portions of the robot100(e.g., disposed around a perimeter of the robot body110) for detecting any nearby or intruding obstacles. The proximity sensors may be converging infrared (IR) emitter-sensor elements, sonar sensors, ultrasonic sensors, and/or imaging sensors (e.g., 3D depth map image sensors) that provide a signal to the controller150when an object is within a given range of the robot100. Moreover, one or more of the proximity sensors410can be arranged to detect when the robot100has encountered a falling edge of the floor, such as when it encounters a set of stairs. For example, a cliff proximity sensor410bcan be located at or near the leading end and the trailing end of the robot body110. The robot controller150(executing a control system) may execute behaviors that cause the robot100to take an action, such as changing its direction of travel, when an edge is detected.

In the example shown, the bumper130includes an array of wall proximity sensors410a(e.g., 10 wall proximity sensors410a) arranged evenly along a forward perimeter of the bumper130and directed outward substantially parallel with the floor surface10for detecting nearby walls. The bumper sensor system400also includes one or more cliff proximity sensors410b(e.g., four cliff proximity sensors410b) arranged to detect when the robot100encounters a falling edge of the floor10, such as when it encounters a set of stairs. The cliff proximity sensor(s)410bcan point downward and be located on a lower portion132of the bumper130near a leading edge136of the bumper130and/or in front of one of the drive wheels124a,124b. In some cases, cliff and/or wall sensing is implemented using infrared (IR) proximity or actual range sensing, using an infrared emitter and an infrared detector angled toward each other so as to have an overlapping emission and detection fields, and hence a detection zone, at a location where a floor should be expected. IR proximity sensing can have a relatively narrow field of view, may depend on surface albedo for reliability, and can have varying range accuracy from surface to surface. As a result, multiple discrete cliff proximity sensors410bcan be placed about the perimeter of the robot100to adequately detect cliffs from multiple points on the robot100.

Referring toFIG. 9, in some implementations, the robot100includes a navigation system600configured to allow the robot100to deposit cleaning liquid on a surface and subsequently return to collect the cleaning liquid from the surface through multiple passes. As compared to a single-pass configuration, the multi-pass configuration allows cleaning liquid to be left on the surface for a longer period of time while the robot100travels at a higher rate of speed. The navigation system600allows the robot100to return to positions where the cleaning fluid has been deposited on the surface but not yet collected. The navigation system600can maneuver the robot100in a pseudo-random pattern across the floor surface10such that the robot100is likely to return to the portion of the floor surface10upon which cleaning fluid has remained.

The navigation system600may be a behavior based system stored and/or executed on the robot controller150. The navigation system600may communicate with the sensor system500to determine and issue drive commands to the drive system120.

FIG. 10provides an exemplary arrangement1000of operation for a method of operating a mobile surface cleaning robot100. The method includes detecting1002an operating state of the robot100and in response to detecting a cleaning state of the robot100, moving1004an orifice sealer230of an orifice220of the collection volume202bof the robot100to an open position, allowing a flow of fluid through the orifice220. The method further includes, in response to detecting a non-cleaning state of the robot100, moving1006the orifice sealer230to a closed position, preventing any flow of fluid through the orifice220.

In some implementations, the method includes detecting the cleaning state by receiving a signal indicating execution of a cleaning operation. The method may include detecting the non-cleaning state by receiving a signal indicating at least one of cessation of the cleaning operation, a wheel drop condition, a cliff detection (e.g., via a cliff sensor410b), robot removal from a floor surface10(e.g., via a cliff sensor410b, wheel drop sensor, and/or an inertial measurement unit), or detachment of the collection volume202bfrom the robot100. Moreover, the non-cleaning state can be detected by receiving a first signal indicating attachment of the collection volume202bto the robot100in combination with a second signal indicating non-execution of a cleaning operation. This may occur when a user reattaches the collection volume202,202bafter servicing.

In some examples, the method includes moving an actuator shaft260longitudinally between open and closed positions through an aperture224defined by the collection volume202b. The actuator shaft260causes movement of the orifice sealer230between its corresponding open and closed positions. The method may also include rotating a cam258that moves the actuator shaft260longitudinally between open and closed positions, causing corresponding movement of the orifice sealer230between its open and closed positions. The method sometimes includes allowing spring biased movement of the orifice sealer230to its close position upon movement of the actuator shaft260to its closed position (or removal of the actuator shaft260).

FIG. 11provides another exemplary arrangement1100of operation for a method of operating a mobile surface cleaning robot100. Referring also toFIG. 8, the method includes blowing1102air onto a floor surface10beneath the robot100, lifting1104substantially dry debris from the floor surface10into a first duct208a, and dispensing1106fluid12onto the floor surface10. The method also includes lifting1108at least one of fluid12or wet debris from the floor surface10into a second duct208b, and moving1110a flow debris from the first duct208aand a flow of the at least one of fluid12or wet debris from the second duct208bboth through a third duct208cinto a collection volume202b.

In some implementations, the method includes allowing an expansion of air in the collection volume202bto allow debris to settle into the collection volume202b. The method may include evacuating air from the collection volume202b. When blowing air onto the floor surface10, the method may include blowing the air from opposite directions toward the first duct208acentrally located on the robot100.

The method may include dispensing the fluid12onto the floor surface10rearward of blowing air onto the floor surface10and rearward of lifting the substantially dry debris from the floor surface10. The method may include dispensing the fluid12onto the floor surface10rearward lifting the at least one of fluid12or wet debris from the floor surface10. The method may include smearing the dispensed fluid12onto the floor surface10. Moreover, the method may include filtering the evacuated air from the collection bin202b.