Patent Publication Number: US-11641990-B2

Title: Debris bins and mobile cleaning robots including same

Description:
RELATED APPLICATION(S) 
     The present application claims the benefit of and priority from U.S. Provisional Patent Application No. 62/611,986, filed Dec. 29, 2017, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This specification relates to bins for a mobile cleaning robots and mobile cleaning robots and methods including bins. 
     BACKGROUND 
     A mobile cleaning robot can navigate over a surface such as a floor and clean debris from the surface. Once collected, the debris can be stored in a volume inside the robot and later removed. 
     SUMMARY 
     According to some embodiments, a mobile cleaning robot includes a removable filter unit configured to receive a supply airflow generated by a blower and to filter debris from the supply airflow, a filter seat, a filter access opening, a filter access door, and a filter presence system. The filter access door is pivotable between a closed position, wherein the filter access door covers the filter access opening, and an open position, wherein the filter access door is displaced from the filter access opening to permit access to the filter seat. The filter presence system is configured to: permit the filter access door to move from the open position into the closed position when the filter unit is disposed in the filter seat; and prevent the filter access door from being moved into the closed position when the filter unit is not disposed in the filter seat. The filter presence system includes a lift arm movable between an extended position and a retracted position. When the filter access door is open, the lift arm assumes the extended position to receive the filter unit in the filter seat. Moving the filter access door from the open position into the closed position when the filter unit is disposed in the filter seat causes the lift arm to move to the retracted position. 
     According to some embodiments, the filter seat is a filter loading seat, and the filter presence system is configured to move the filter unit from a filter loading position to an installed filter seat when the filter access door is moved from the open position into the closed position with the filter unit disposed in the filter loading seat. 
     In some embodiments, when the filter unit is disposed in the filter loading seat and the filter access door is moved from the open position toward the closed position, the filter access door will contact the filter unit and push the filter unit into the installed filter seat, and when the filter unit is not disposed in the filter loading seat and the filter access door is moved from the open position toward the closed position, the filter access door will interlock with the lifting arm to prevent the filter access door from being moved into the closed position. 
     According to some embodiments, the mobile cleaning robot defines an internal containment chamber. The mobile cleaning robot includes an internal barrier that separates the internal containment chamber into first and second subchambers. The internal barrier includes an aperture providing fluid communication between the first and second subchambers. When positioned in the installed filter seat, the filter unit is supported by the internal barrier and over the aperture to filter airflow through the aperture. 
     In some embodiments, the lift arm is a first lift arm, and the mobile cleaning robot includes a second lift arm located opposite the first lift arm. The first and second lift arms define the filter loading seat therebetween. 
     The lift arm may be spring loaded toward the extended position. 
     In some embodiments, the lift arm is configured to pivot between the extended position and the retracted position about a pivot axis. 
     According to some embodiments, the mobile cleaning robot includes an interlock feature located on one of the filter access door and the lift arm. The interlock feature is configured to interlock with the other of the filter access door and the lift arm when the filter access door is moved toward the closed position without the filter unit disposed in the filter seat and to thereby prevent the filter access door from moving into the closed position. 
     In some embodiments, the interlock feature is an integral first interlock feature on the filter access door, the mobile cleaning robot includes an integral second interlock feature on the lift arm, one of the first and second interlock features is an interlock slot, and the other of the first and second interlock features is an interlock tab. The filter presence system is configured such that the interlock tab interlocks with the interlock slot when the filter access door is moved toward the closed position without the filter unit disposed in the filter seat, and the interlock between the interlock tab and the interlock slot prevents the filter access door from moving into the closed position. 
     The mobile cleaning robot may include a bin seating, and a debris bin removably and replaceably disposed in the bin seating. The filter seat, the filter access opening, the filter access door, and the filter presence system each form a part of the debris bin. 
     In some embodiments, the mobile cleaning robot includes a bin retention system to retain the debris bin in the bin seating. The bin retention system includes a latch mechanism selectively movable between a locking position, wherein the latch mechanism prevents displacement of the debris bin from the bin seating, and a releasing position, wherein the latch mechanism permits displacement of the debris bin from the bin seating. 
     According to embodiments, a debris bin for a mobile cleaning robot including a support structure includes a bin housing, a removable filter unit, a filter access door, and a filter presence system. The bin housing is configured to be removably and replaceably mounted in the support structure. The bin housing includes a filter seat, and a filter access opening. The removable filter unit is configured to receive a supply airflow and to filter debris from the supply airflow. The filter access door is pivotable between a closed position, wherein the filter access door covers the filter access opening, and an open position, wherein the filter access door is displaced from the filter access opening to permit access to the filter seat. The filter presence system is configured to: permit the filter access door to move from the open position into the closed position when the filter unit is disposed in the filter seat; and prevent the filter access door from being moved into the closed position when the filter unit is not disposed in the filter seat. The filter presence system includes a lift arm movable between an extended position and a retracted position. When the filter access door is open, the lift arm assumes the extended position to receive the filter unit in the filter seat. Moving the filter access door from the open position into the closed position when the filter unit is disposed in the filter seat causes the lift arm to move to the retracted position. 
     According to embodiments, a mobile cleaning robot includes a bin seating, a drive system, a blower, a filter unit, and a bin retention system. The drive system is operative to move the mobile cleaning robot. The blower is operative to generate a supply air flow. The debris bin is removably and replaceably disposed in the bin seating. The filter unit is disposed in the debris bin and in a path of the supply air flow. The bin retention system is configured to retain the debris bin in the bin seating. The bin retention system includes a latch mechanism selectively movable between a locking position, wherein the latch mechanism prevents displacement of the debris bin from the bin seating, and a releasing position, wherein the latch mechanism permits displacement of the debris bin from the bin seating. 
     In some embodiments, the debris bin includes a handle pivotable between a stored position and a raised position, and the bin retention system is transitioned from the locking position to the releasing position by pivoting the handle from the stored position to the raised position. 
     In some embodiments, the handle includes a handle body configured to be grasped by a user, the handle body is oriented substantially horizontal when the handle is in the stored position, and the handle body is oriented substantially vertical when the handle is in the raised position. 
     According to some embodiments, the mobile cleaning robot includes a support structure and the bin retention mechanism includes: a latch portion on the handle; and a latch member on the support structure, the latch member being displaceable relative to the bin seating. The latch portion engages the latch member and is movable with the handle such that: when the handle is in the stored position, the latch portion interlocks with the latch member to prevent displacement of the debris bin from the bin seating; and when the handle is transitioned from the stored position to the raised position and the debris bin is lifted from the bin seating, the latch portion displaces the latch member relative to the bin seating to permit displacement of the debris bin from the bin seating. 
     In some embodiments, the latch portion includes a cam feature that displaces the latch member as the handle is transitioned form the stored position to the raised position. 
     In some embodiments, the latch member is spring loaded. 
     The latch member may include a rounded engagement end that contacts the latch portion as the debris bin is inserted into the bin seating. 
     In some embodiments, the mobile cleaning robot includes a filter seat, a filter access opening, a filter access door, and a filter presence system. The filter access door is pivotable between a closed position, wherein the filter access door covers the filter access opening, and an open position, wherein the filter access door is displaced from the filter access opening to permit access to the filter seat. The filter presence system is configured to: permit the filter access door to move from the open position into the closed position when the filter unit is disposed in the filter seat; and prevent the filter access door from being moved into the closed position when the filter unit is not disposed in the filter seat. 
     Further features, advantages and details of the present invention will be appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the embodiments that follow, such description being merely illustrative of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a top, front perspective view of a mobile cleaning robot according to embodiments of the invention. 
         FIG.  2    is a bottom, front perspective view of the mobile cleaning robot of  FIG.  1   . 
         FIG.  3    is a top perspective view of the mobile cleaning robot of  FIG.  1    wherein a debris bin thereof is removed. 
         FIG.  4    is a top perspective view of the mobile cleaning robot of  FIG.  1    wherein the debris bin is installed and a bin access lid of the mobile cleaning robot is in an open position. 
         FIG.  5    is a cross-sectional view of the mobile cleaning robot of  FIG.  1    taken along the line  5 - 5  of  FIG.  1   . 
         FIG.  6    is a top perspective view of a filter unit forming a part of the mobile cleaning robot of  FIG.  1   . 
         FIG.  7    is a front perspective view of the debris bin of  FIG.  4   , wherein a filter access door thereof is in a closed position. 
         FIG.  8    is a rear perspective view of the debris bin of  FIG.  4   , wherein the filter access door is in an open position, a handle forming a part of the debris bin is in a partially raised position, a bottom panel forming a part of the debris bin is in an open position, and the filter unit is positioned in an installed filter seat of the debris bin. 
         FIG.  9    is a fragmentary, rear perspective view of the debris bin of  FIG.  4   , wherein the filter access door is in the open position, lift arms of the debris bin are in an extended position, and the filter unit is positioned in a filter loading seat of the debris bin. 
         FIG.  10    is a top view of the debris bin of  FIG.  4    in the configuration of  FIG.  9   . 
         FIG.  11    is a side view of the debris bin of  FIG.  4   , wherein the filter unit is positioned in the filter loading seat and the filter access door is partially closed to a point of contact with the filter unit. 
         FIG.  12    is a cross-sectional view of the debris bin of  FIG.  4    taken along the line  5 - 5  of  FIG.  1   . 
         FIG.  13    is a fragmentary, rear perspective view of the debris bin of  FIG.  4   , wherein the filter unit is not in the debris bin and the filter access door is open. 
         FIG.  14    is a fragmentary, rear perspective view of the filter access door of  FIG.  7   . 
         FIG.  15    is a cross-sectional view of the debris bin of  FIG.  4   , wherein the filter unit is not in the debris bin and the filter access door is open. 
         FIG.  16    is a cross-sectional view of the debris bin of  FIG.  4   , wherein the filter unit is not in the debris bin and the filter access door is locked open by a filter presence system forming a part of the debris bin. 
         FIG.  17    is an enlarged, fragmentary view of the debris bin configured as shown in  FIG.  16   . 
         FIG.  18    is a fragmentary, perspective view of the mobile cleaning robot of  FIG.  1    showing a latch mechanism thereof. 
         FIG.  19    is a perspective view of a latch member forming a part of the latch mechanism of  FIG.  18   . 
         FIG.  20    is a fragmentary, perspective view of the latch mechanism of  FIG.  18    in a latched position. 
         FIG.  21    is a cross-sectional view of the latch mechanism taken along the line  21 - 21  of  FIG.  20   . 
         FIG.  22    is a cross-sectional view of the latch mechanism taken along the line  21 - 21  of  FIG.  20   , wherein the latch mechanism is in a releasing position. 
         FIG.  23    is a cross-sectional view of the latch mechanism taken along the line  23 - 23  of  FIG.  22   , wherein the latch mechanism is in the releasing position. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. In the drawings, the relative sizes of regions or features may be exaggerated for clarity. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     It will be understood that when an element is referred to as being “coupled” or “connected” to another element, it can be directly coupled or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly coupled” or “directly connected” to another element, there are no intervening elements present. Like numbers refer to like elements throughout. 
     In addition, spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein the expression “and/or” includes any and all combinations of one or more of the associated listed items. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     The term “monolithic” means an object that is a single, unitary piece formed or composed of a material without joints or seams. 
     A mobile cleaning robot can navigate around a room or other locations and clean a surface over which it moves. In some implementations, the robot navigates autonomously, however user interaction may be employed in certain instances. The mobile cleaning robot collects dust and debris from the surface and stores the dust and debris in a bin (e.g., a debris bin) that can be later emptied (e.g., at a later time when the bin is at or near capacity). In some embodiments, the bin is designed for removal and emptying by a user, automatic evacuation by an evacuation device, or manual evacuation by a handheld vacuum means external to the robot. The bin rests inside the mobile cleaning robot and is positioned in an airflow path through the mobile cleaning robot for retaining debris vacuumed into the bin by the airflow. The airflow path assists in pulling debris from the surface, through the mobile cleaning robot and into the bin. The bin filters the air and a blower expels the filtered air through a vent in the mobile cleaning robot. 
       FIGS.  1 - 23    show an exemplary mobile cleaning robot  100  that can autonomously navigate a cleaning surface and perform cleaning operations (e.g., vacuum operations) on a cleaning surface. The mobile cleaning robot  100  has a forward portion  104  and an aft portion  106 . The mobile cleaning robot  100  includes a modular debris bin  130 , a filter unit  150 , a blower  118  ( FIG.  5   ; e.g., a vacuum source), a cleaning head  108 , a motive or drive system  194  for moving the mobile cleaning robot  100 , a corner brush  110 , a guidance system  195 , a rear caster wheel  196 , an energy storage battery  197 , and an onboard controller  198 . The debris bin  130  and the filter unit  150  collectively form a filtered bin assembly  130 ′ ( FIG.  7   ). 
     The robot  100  further includes a filter presence system  160  and a bin retention system  180 , as described in more detail below. 
     In some implementations of the mobile cleaning robot  100 , the forward portion  104  is square cornered with a substantially flat leading edge and the aft portion  106  is a rounded or semi-circular trailing edge, giving the mobile cleaning robot  100  a D-shaped or tombstone-shaped peripheral profile. In other implementations, the mobile robot  100  may have another peripheral profile shape such as a round profile, a triangular profile, an elliptical profile or some non-symmetrical and/or non-geometric shape or industrial design. 
     The drive system  194  ( FIG.  2   ) includes left and right drive wheels  194 A and one or more motors  194 B operable to drive the wheels  194 A. The drive wheels  194 A may be independent drive wheels that mobilize the robot  100  and provide two points of contact with the floor surface. The drive wheels  194 A may be spring loaded. The multi-directional caster wheel  196  provides additional support for the robot  100  as a third point of contact with the floor surface. The electric drive motor or motors  194 B are disposed in the housing and operative to independently drive the wheels  194 A. The motive components may include any combination of motors, wheels, drive shafts, or tracks as desired, based on cost or intended application of the robot  100 . 
     The guidance system  195  ( FIGS.  1  and  2   ) includes cliff detection sensors  195 A, a recessed optical mouse sensor  195 B aimed at the floor surface for detecting drift, and a camera  195 C. 
     The cleaning head  108  includes cleaning elements or extractors  108 A such as rotatable rollers mounted at a suction opening  108 B in the underside of the robot  100 . The cleaning head  108  may further include a motor operable to forcibly rotate the extractors  108 A. The extractors  108 A may be brush rollers and/or pliable rubber rollers, for example. 
     The blower  118  may be an electrical impeller fan or other vacuum source for generating airflow within the mobile cleaning robot  100 . 
     The controller  198  (e.g., a microprocessor-based controller and associated memory) may control the drive motor  194 C, the cleaning head  108 , and the blower  118  using data input from the sensors  195 A-C and/or other data. 
     The drive motor  194 C, the guidance system  195  and the blower  118  may be powered by the onboard battery  197 . 
     The mobile cleaning robot  100  includes a rigid support structure  102 . The support structure  102  forms a structure that supports the blower  118 , the battery  197 , and the cleaning head  108 . A bin emptying door or bottom cover  111  may be mounted on the bottom of the structure  102 . The support structure  102  may include a unitary or non-unitary frame, chassis, body, or assembly, for example. 
     The support structure  102  also forms a bin receiving compartment, well or seating  120  for receiving or otherwise supporting the debris bin  130 . The bin  130  can be inserted into and removed from the seating  120  selectively for servicing. When installed or received in the mobile cleaning robot  100 , the debris bin  130  can collect and store debris collected from the surface being cleaned. 
     The seating  120  has a heightwise or main axis A-A ( FIG.  5   ) and a lateral axis B-B ( FIG.  3   ). In some embodiments, the lateral axis B-B is substantially horizontal. In some embodiments, the lateral axis B-B is substantially perpendicular to the main axis A-A. 
     The seating  120  includes one or more sidewalls  114  and a floor  113  that form a cavity in the support structure  102  for receiving the debris bin  130 . The lower boundary of the seating  120  is defined by the floor  113  on which the debris bin  130  rests when the bin  130  is inserted into the seating  120 . 
     The seating  120  may have one or more peripheral profiles for receiving a matching profile of the debris bin  130  in a unique orientation that ensures complete insertion of the bin  130  and secure alignment of mating features between the debris bin  130  and the support structure  102 . For example, the one or more peripheral profiles may be utilized to produce one or more keyed features  114 B (e.g., a bump, indent, protrusion, etc.) so that the bin  130  is received in a particular orientation. The keyed feature  114 B matches a complementary keyed feature of the bin  130 . In some implementations, a portion of the sidewall  114  is tilted from vertical or the main axis A-A to form a downward and inward taper from a surface of the mobile cleaning robot  100  to the floor  113  of the seating  120 . For example, all or a portion of the sidewall  114  can be sloped to form a fully or partially funneled or conical shape. A sidewall (e.g., sidewall  138 ) of the debris bin  130  can be shaped to match the sidewall  114  of the seating  120 . For example, the seating  120  and the bin  130  may have matching non-circular shapes, such as D-shapes as shown. In some implementations, one or more portions of the sidewall  114  can be flat or approximately flat to accommodate alignment of one or more entrance and evacuation ports of the debris bin  130  with the airflow path FP of the mobile cleaning robot  100 . 
     The shape of the seating  120  assists in properly inserting and orienting the debris bin  130  in the structure  102 . During insertion, the one or more keyed features  114 B can guide the bin  130  in for an appropriate positioning of the bin in the seating. A user may receive one or more types of feedback indicating a proper positioning of the debris bin  130 . For example, such feedback can include audible feedback (e.g., a click, beep, or tap), tactile feedback (e.g., a physical sensation for the user such as sensing physical resistance, etc.), and/or visible feedback (e.g., a green light illuminates on a user interface of the mobile cleaning robot  100  and/or an associated application operating on a remote device communicating wirelessly with the mobile cleaning robot  100 ). 
     The mobile cleaning robot  100  includes a bin access lid or panel  112  that covers the seating  120 . The bin access panel  112  encloses the debris bin  130  within the mobile cleaning robot  100  and prevents the debris bin  130  from being removed during a cleaning mission. The bin access panel  112  is affixed to the support structure  102  by a panel hinge  116  such that the bin access panel  112  can be selectively rotated open and closed over the seating  120 . 
     In some implementations, the bin access panel  112  closes over the bin  130  only when the debris bin  130  is seated in the structure  102  with the debris bin  130  resting on the floor  113  of the seating  120  and the filter access door  134  closed. If the debris bin  130  is rotated or only partially inserted so that it is not fully inserted within the seating  120 , or if a door  134  of the bin  130  is not fully closed, the bin access panel  112  will not swing closed to cover the debris bin  130 . In such cases the bin access panel  112  may remain sufficiently ajar that it provides a visual indication to a user that the debris bin  130  is not properly seated or closed, thereby providing a visual prompt that corrective action is needed. In some implementations, the mobile cleaning robot  100  includes one or more mechanisms to prevent the mobile cleaning robot  100  from operating when the bin access panel  112  is ajar. In some implementations, the mobile cleaning robot  100  includes one or more mechanisms to prevent the mobile cleaning robot  100  from operating if the bin access panel  112  is forced closed despite the debris bin  130  not being seated against the floor  113  of the seating  120  or closed. 
     The bin  130  includes a housing  131 , a filter access lid or door  134 , an interior barrier  137 , a door latch mechanism  148 , a handle  149 , and the filter presence system  160 . 
     The bin housing  131  has a forward end  130 A and an aft end  130 B. The housing  131  includes a top wall  133 , an emptying door or bottom wall  132 , a sidewall  138 , and an internal barrier  137 . The top wall  133  defines a filter access opening  140 A. The top wall  133 , the bottom wall  132 , and the sidewall  138  collectively define an internal containment volume or chamber  140  in fluid communication with the opening  140 A. The internal barrier  137  is disposed in the chamber  140 . 
     The sidewall  138  wraps around the sides of the bin  130  in a shape that is complementary to the seating  120 . The sidewall  138  includes an exhaust port  144  and an intake port  142 . In some implementations, the sidewall  138  includes one or more keyed features, such as an indent, that assists a user in grasping the bin  130  and that ensures properly orienting the bin  130  in the seating  120 . The one or more keyed features include any number of asymmetrical features of the sidewall  138  that assist the user for orienting the bin  130  when placing the bin in the seating  120 . The asymmetry of the keyed features prevents the bin  130  from rotating or shifting inside the seating  120 , such as during operation of the mobile cleaning robot  100 . 
     In some implementations, the intake port  142  includes an elongated, pseudo-elliptical aperture that matches an abutting aperture of a debris intake duct  122  ( FIG.  5   ) of the cleaning head  108 . In some implementations, the edge of the intake port  142  includes a pliable lip that forms an intake port seal for sealing the intake port with the duct  122  when the bin  130  is fully installed in the seating  120 . 
     When the bin  130  is seated in the seating  120 , the exhaust port  144  aligns with an intake duct  118 A ( FIG.  5   ) of the blower  118 . In some implementations, an exhaust port seal (e.g., a pliable lip) is provided around the exhaust port  144  and forms a seal with the surface about the blower intake duct  118 A. 
     The filter access door  134  is pivotably coupled to the top wall  133  by a hinge  135 . The filter access door  134  includes a door body or panel  134 B and integral latch features  134 C. The door  134  can be rotated about a pivot axis C-C ( FIG.  8   ) of the hinge  135  between a closed position ( FIGS.  7  and  12   ) and an open position ( FIGS.  9  and  11   ). In its closed position, the door  134  fully covers and closes the opening  140 A, and thereby forms a further wall defining the chamber  140 . In its open position, the door  134  is displaced from and does not cover the opening  140 A, thereby opening the chamber  140  to access by a user. 
     The latch features  134 C are positioned and configured to releasably engage a cooperating latch feature (e.g., slots or a ledge) on the housing  131  to releasably secure the door  134  in the closed position. The door  134  may include a seal  134 A (e.g., a pliable rubber strip) to form a fluid tight seal between the door  134  and the housing  131  when the door  134  is closed and latched. The seal  134 A prevents air from passing through the opening  140 A when the filter door  134  is closed. 
     The filter door body  134 B may be formed of a transparent material such that the filter unit  150  is visible in the bin  130  when the filter door  134  is closed. The filter door  134  is positioned to allow access to the filter unit  150  so that the user can replace or remove the filter unit  150  from the bin  130  without removing the top wall  133  of the bin. 
     The filter door  134  further includes an integral door flange  162  and integral interlock features  164 , as discussed in more detail below with regard to the filter presence system  160 . 
     The internal barrier  137  includes a lip or ledge  166  and defines a filter flow through aperture  141  ( FIG.  5   ). The interior barrier  137  separates or partitions the chamber  140  into a lower or first internal containment subchamber or volume  140 L and an upper or second internal containment subchamber or volume  1401  on either side of the internal barrier  137 . The first volume  140 L is fluidly connected to the second volume  140 U by the filter flow through aperture  141 . 
     A seal  166 A ( FIG.  12   ) can be mounted on the ledge  166 . The seal  166 A may be a rubber strip or other sealing material. The seal  166 A may extend fully about the perimeter of the aperture  141 . 
     In use, the filter unit  150  is installed over the aperture  141 . The filter unit  150  is supported inside the containment volume  140  by the internal barrier  137  and rests on the ledge  166  surrounding the aperture  141 . The ledge  166  defines an installed filter seat  143  to receive and hold the filter unit  150  during cleaning operations. 
     During cleaning operations, the first volume  140 L receives dust-laden air and debris from the cleaning head  108  though the intake port  142  and expels air through the filter unit  150 . During operation, the second volume  140 U receives filtered air from the first volume  140 L through the filter unit  150  and expels air through the exhaust port  144 . The blower  118  sucks in cleaned air through the exhaust port  144  and expels the air from the mobile cleaning robot  100 , through a vent  126  in the aft portion  106 . 
     The first volume  140 L stores the debris collected by the cleaning head  108 , such as dust or debris lifted from a cleaning surface on which the mobile cleaning robot  100  travels. 
     The internal barrier  137  prevents airflow FP from entering the second volume  140 U of the bin  130  from the first volume  140 L, and thereby prevents entry of debris from the first volume  140 L to the second volume  140 U except through the aperture  141 . 
     In some implementations, the exhaust port  144  is located nearer the top wall  133  than the bottom wall  132  to allow the first volume  140 L to be relatively larger in size. 
     In some embodiments, a bottom door opening  140 B is defined in the bottom of the bin  130  and the bottom wall  132  is a door that is pivotably coupled to the sidewall  138  by a hinge  136 . The bottom door  132  can be selectively pivoted about the hinge  136  between a closed position and an open position. In its closed position, the door  132  fully covers and closes the opening  140 B. In its open position, the door  132  is displaced from and does not cover the opening  140 B, thereby opening the chamber  140  to empty the bin  130 . 
     The bin  130  further includes a latch mechanism including a door latch  148 B and an actuator button  148 A. The latch  148 B extends from an edge of the bottom wall  132 . The latch  148 B extends from the edge of the bottom wall  132  and releasably secures the edge to the sidewall  138 . The button  148 A can be depressed to open the latch  148 B to release the bottom wall  132  for emptying the bin  130 . 
     In some implementations, a seal extends around the edge of an interior surface of the bottom wall  132 . The seal prevents air from entering and debris from exiting the bin  130  through the bottom of the bin  130  when closed with the latch  148 B. 
     In some implementations, the bin  130  includes an evacuation port  146 . The evacuation port  146  is an additional port in the bottom wall  132  that remains closed during some operations, such as cleaning operations, but can open for other operations, such as bin  130  evacuation operations. The seating  120  includes a seating aperture  125  in the floor  113 . When the bin  130  is properly seated in the structure  102 , the evacuation port  146  of the bin  130  aligns with the seating aperture  125 . 
     The bottom cover  111  has a bottom surface including a bottom surface aperture  111 A. The bottom surface aperture  111 A aligns with the seating aperture  125  to form an open passage from the bin  130  inside the mobile cleaning robot  100  to the exterior of the mobile cleaning robot  100 . The open passage enables evacuation of the bin  130  while the bin is seated inside the mobile cleaning robot  100 , such as by an external evacuation mechanism. 
     Evacuation can occur autonomously from an external evacuation station. When the mobile cleaning robot  100  determines that evacuation of the debris bin  130  is needed (e.g., the bin  130  is full or at the request of a remote application such as a mobile device application), the mobile cleaning robot  100  navigates to the evacuation station. The evacuation station can be integrated with a docking station (e.g., a charging dock). For example, evacuation can occur during a recharge of a power system of mobile cleaning robot  100 . When the mobile cleaning robot  100  navigates to the external evacuation station, the evacuation port  146  aligns with a suction mechanism of the external evacuation station, and the debris inside the bin  130  is sucked from the bin  130  through the evacuation port  146 . In some embodiments, a user possesses a remote computing device (e.g., a mobile phone or other mobile device) that includes a robot control application and is networked to the robot  100 . The robot control application enables the user to monitor the fullness state of the debris bin  130  via the mobile device (e.g., by sending a request to and/or receiving an unsolicited notification from the robot  100 ). The user can then use the robot control application to send the robot  100  a command to empty the bin  130 , responsive to which the mobile cleaning robot  100  will navigate to the evacuation station. 
     The evacuation port  146  may include a valve or movable flap or barrier that moves between an open position and a closed position. The movable barrier selectively seals and opens enabling evacuation of the contents of the bin  130 . In the closed position, the flap blocks air flow between the debris bin and the environment. In the open position, a path is formed in the open passage through the flap between the debris bin  130  and the evacuation port  146 . The movable barrier may open in response to a difference in air pressure at the evacuation port  146  and within the debris bin  130 . The evacuation station can generate a negative air pressure (e.g., a suction force) that causes the flap to open and sucks the debris out of the bin  130  and to the evacuation station. The evacuation of the bin  130  by the evacuation station can occur autonomously without the bin  130  being removed from the mobile cleaning robot  100 . The bin  130  may include a biasing mechanism (e.g., a torsion spring) that biases the movable barrier into the closed position. 
     The handle  149  includes a handle body  149 A, opposed integral hinge portions  149 B, and opposed integral handle latch portions  184 . In some embodiments and as shown, the handle latch portions  184  are located on the hinge portions  149 B. 
     The handle  149  is pivotably coupled by the hinge portions  149 B to the top wall  133  by opposed hinges H 2 . The hinges H 2  enable the handle  149  to pivot about a pivot axis E-E ( FIG.  8   ) in a direction F ( FIG.  21   ) between a stored or retracted position ( FIGS.  7  and  21   ) and a raised or extended position ( FIG.  22   ). 
     In some embodiments, the handle  149  is substantially orthogonal with the top wall  133  in the extended position. In some implementations, the handle  149  lies on or closely adjacent the top wall  133  when in the stored state. In some implementations, the handle  149  is disposed in a recess of the top wall  133  of the bin  130  during the stored state such that the handle  149  and the top wall  133  of the bin  130  form an approximately flush surface. Such a configuration can reduce the overall volume envelope of the bin  130 . The bin access panel  112  can close over the bin  130  and the handle  149  without the handle  149  protruding from the mobile cleaning robot  100 . 
     In some implementations, the locations of the handle hinges H 2  and the pivot axis E-E are chosen to be along or near an approximate center of mass of the bin  130  such that the bin, when hanging from the hinged handle  149 , is nearly or approximately balanced and level but the bin inlet  142  tipped upward. For example, the user can grasp the handle  149  and lift the bin  130  with a single hand without needing to balance or steady the bin with a second hand. 
     Each handle latch portion  184  includes integral, geometric latch features  185 A,  185 B ( FIG.  18   ). The latch feature  185 A is a substantially flat or planar land. The land  185 A may define a substantially horizontal plane. The plane of the land  185 A may be non-intersecting with the handle hinge axis E-E. The latch feature  185 B is an angled surface that is angled obliquely with respect to the axis M-M ( FIG.  23   ). In some embodiments and as shown, the latch feature  185 B is a generally truncated circular ramp. The ramp  185 B extends from a lead end  185 C to the land  185 A. The ramp  185 B tapers in a direction from the land  185 B to the lead end  185 C. The lead end  185 C may terminate in the plane of the outer face  149 C of the handle hinge portion  149 B so that the transition from the outer face  149 C to the ramp  185 B is smooth and stepless. The ramp  185 B may have a smooth profile that follows a uniform or nonuniform curve. A socket  185 D is defined by the land  185 A and the outer face  149 C above the land  185 A. In some embodiments, the latch feature  185 B serves as a displacement guide ramp. In some embodiments, the latch feature  185 B operates as a cam. 
     The latch features  185 A,  185 B may be molded, machined or otherwise formed in the ends of the handle  149 . In some embodiments, the latch portions  184  are monolithic with the remainder of the handle  149 . 
     The filter unit  150  includes a frame  152  and filter media  156 . The frame  152  includes opposed side walls  152 A and opposed end walls  152 B,  152 C. The walls  152 A,  152 B may be integrated to form an endless closed wall or casing, as shown. The walls  152 A,  152 B define a through passage  154 . The filter media  156  is contained in and spans the through passage  154 . In some embodiments, the walls  152 A,  152 B are U-shaped (in cross-section) rails that receive the edges of the filter media  156 . The frame  152  may include crossbeams  152 D extending between the end walls  152 B,  152 C and across the through passage  154  to support the filter media  156 . A pull-tab  157  protrudes from the frame  152 . The pull-tab  157  is sized to be grasped by a user for removal of the filter unit  150  from the bin  130 . 
     The filter media  156  may be formed of any suitable material. In some implementations, the filter material  156  includes a fibrous material that allows air to pass through the material but traps dust, debris, etc. The filter material  156  may include folds that increase the surface area of the filter material exposed to the airflow path. In some embodiments, the filter material  156  covers the entire airflow path through the filter unit  150 . 
     The filter frame  152  may be formed of any suitable material. In some implementations, the frame  152  is formed of a rigid polymeric material. 
     The filter presence system  160  includes the ledge  166  of the internal barrier  137 , the interlock features  164  of the filter door  134 , and a lifting mechanism  170 . The components of the system  160  cooperate to position the filter unit  150  for use and removal, and to prevent closure of the filter door  134  when a filter unit  150  is not in place. 
     With reference to  FIGS.  9 ,  10  and  13   , the lifting mechanism  170  includes a pair of laterally opposed lift arms  172 . Each arm  172  has a proximal or pivot end  172 A and a distal or free end  172 B. Each arm  172  is pivotally coupled to the bin housing  131  by an integral hinge post  175 A at a hinge H 1 . The hinges H 1  enable the arms  172  to pivot about a hinge pivot axis G-G ( FIG.  13   ) between a prescribed retracted position ( FIGS.  5 ,  7 ,  8  and  12   ; which may also be referred to as a seated position) and a prescribed extended position ( FIGS.  9 - 11 ,  13  and  15   ; which may also be referred to as a deployed or receiving position). In the retracted position, the arms  172  are positioned adjacent or in contact with the ledge  166 . In the extended position, the arms  172  are raised above the ledge  166 . The hinge post  175 A has a limiter stop tab  175 B to limit upward pivot of the arm  172  to the prescribed raised position. The arm  172  may further include an integral guide slot  175 C that slidably receives a fixed guide post  175 D to stabilize the arm throughout its motion. 
     Each arm  172  includes a longitudinally and vertically extending main or side wall  172 D. Each arm  172  also includes a filter support tab  172 C projecting laterally inwardly from the lower edge of the side wall  172 D proximate the free end  172 B. The side walls  172 D and the support tabs  172 C collectively form a filter loading seat  171  to receive and support the filter unit  150 . 
     Each arm  172  includes an interlock feature in the form of a stop tab or wall  173 . Each arm  172  further includes recess  174  laterally adjacent and defined by the stop wall  173 . Each stop wall  173  and recess  174  is located at the free end  172 B of the associated arm  172 . The stop wall  173  has an end edge  173 A. 
     Each arm  172  is biased or loaded from the retracted position to the extended position by a biasing mechanism. In some embodiments and as shown, each biasing mechanism is a spring  176  and each arm  172  is spring loaded. The springs  176  may be coil springs, for example. However, other types of biasing mechanisms or springs may be used. A single biasing mechanism (e.g., spring) may be used to bias both arms  172 , or one or both of the arms  172  may be biased by more than one biasing mechanism. 
     With reference to  FIGS.  14  and  17   , each interlock feature  164  includes a portion  162 B of the flange  162 , an end wall  164 A, and an outer side wall  164 B. The end wall  164 A extends laterally outward from the flange portion  162 B and depends downwardly or inwardly from the door  134 . The outer side wall  164 B extends rearwardly (with respect to the support structure  102 ) from the end wall  164 A. The walls  162 B,  164 A,  164 B collectively define an interlock socket or slot  165 . The interlock slot  165  is open from the rear and below. 
     The bin retention system  180  includes the handle latch portions  184  and two opposed latch assemblies  186 A,  186 B ( FIGS.  3  and  18   ). The latch portion  184  on the right side of the bin  130  and the latch assembly  186 A cooperatively form a right side latch mechanism  182 A. The latch portion  184  on the left side of the bin  130  and the latch assembly  186 B cooperatively form an opposing left side latch mechanism  182 B. The bin retention mechanism  180  serves to retain the debris bin  130  in the seating  120  unless and until an operator chooses to remove the bin  130 . The bin retention system  180  can then be operated to selectively release the bin  130  from the support structure  102  to permit the bin  130  to be removed from the seating  120 . 
     Each latch assembly  186 A,  186 B includes a latch member  187  and a biasing mechanism  188 . In some embodiments and as shown, each biasing mechanism is a spring  188  and each latch number  187  is spring loaded. The springs  188  may be torsion springs, for example. However, other types of biasing mechanisms or springs may be used. 
     Each latch member  187  includes a pivot end  187 B and an opposing distal or free end  187 C. An integral engagement or latch portion or tab  183  projects laterally from the free end  187 C. The latch tab  183  has a chamfered or rounded end face  183 A. The end face  183 A is rounded on its upper edge  183 B and has a relatively sharp cornered lower edge  183 D. 
     Each latch member  187  is mounted in the support structure  102  such it pivots about its pivot end  187 B and the latch tab  183  projects through a hole  189  ( FIG.  18   ) in the side wall  114  into the seating  120 . The associated spring  188  biases or loads the latch tab  183  into the seating  120  in an inward direction J ( FIG.  23   ). However, the associated spring  188  permits the latch tab  183  to be depressed or displaced in an outward direction K along a latch axis M-M ( FIG.  23   ) into the corresponding hole  189 . 
     The mobile cleaning robot  100  may be used as follows to execute cleaning of a surface. The operation of the robot  100  will first be described with the filter unit  150  installed in the bin  130 , and the bin  130  installed in the seating  120 . Methods for installing the filter unit  150  in the bin  130  and removing the filter unit  150  from the bin  130  are discussed below. Methods for installing the bin  130  in the support structure  102  and removing the bin  130  from the support structure  102  are also discussed below. 
     The bin  130  is fully seated in the seating  120 . The bin access panel  112  covers the debris bin  130  and is secured in the closed position by the latch features  134 C. In some implementations, the robot  100  is configured such that when the bin access panel  112  is ajar or when the debris bin  130  is not present or properly positioned in the seating  120 , the mobile cleaning robot  100  will not perform cleaning operations (e.g., autonomous vacuuming). In some implementations, the robot  100  is configured such the bin access panel  112  cannot be closed when the debris bin  130  improperly seated in the seating  120 . As discussed below, the bin  130  is mechanically secured in the seating  120  by the bin retention mechanism  180 . 
     The filter unit  150  is positioned in the filter loading seat  171  and the arms  172  are in the retracted position. The filter access door  134  is closed over the filter unit  150  and secured closed by the latch features  134 C. The filter unit  150  is thereby positioned on the ledge  166  in the second volume  140 U and between the filter access door  134  and the internal barrier  137 . 
       FIG.  5    is a schematic side view cutaway of the mobile cleaning robot  100  showing placement of the debris bin  130  within the mobile robot  100  and the path of an airflow FP through the mobile robot  100  as indicated by a dashed line. 
     During operation, the debris bin  130  is disposed in the airflow path FP and the blower  118  pulls air through the debris bin  130 . The blower  118  pulls air through the cleaning head  108  and the bin  130  to create a negative pressure (e.g., vacuum pressure effect) on a cleaning surface that is proximate to the cleaning head  108 . In some implementations, the airflow FP is a pneumatic airflow. The air of the airflow FP carries debris and dirt into the debris bin  130  from the cleaning surface. The air is cleaned by the filter unit  150  disposed in the bin  130 , through which the airflow path FP proceeds during operation of the mobile cleaning robot  100 . Clean air is expelled through the vent  126 . 
     The airflow FP path proceeds sequentially from the cleaning head  108 , through the debris intake duct  122 , through the intake port  142 , and into the debris bin  130  through the intake port  142 . The airflow path FP continues from the intake port  142  into the first volume  140 L, through the filter unit  150  from the first volume  140 L into the second volume  140 U. The airflow path FP proceeds from the second volume  140 U, through the bin exhaust port  144 , through the exhaust port  118 A, through the blower  118 , and is then expelled from the mobile cleaning robot  100  through the vent  126 . 
     The debris bin  130  thereby receives debris carried by the airflow FP. The air is filtered by the filter unit  150  so that cleaned air passes through the filter unit  150  into the second containment volume  140 U, and debris removed from the air is retained in the first containment volume  140 L on the adjacent side of the filter media  156  and/or deposited in the first containment volume  140 L. The first containment volume  140 L stores dust and debris collected by the mobile cleaning robot  100  during operation (e.g., cleaning operations). 
     The shape of the first volume  140 L determines how the first volume  140 L fills with debris during operation. In some implementations, the shape of the first volume  140 L, defined partly by the internal barrier  137 , causes the first volume  140 L to backfill with debris during operation of the mobile cleaning robot  100 . The airflow carries debris into the first volume  140 L through the intake port  142 . As the air is sucked through the filter unit  150  into the second volume  140 U, the debris inside the first volume  140 L does not pass through the internal barrier  137 . In some implementations, the internal barrier  137  pushes heavier debris toward the bottom wall  132  of the bin  130  and away from the filter unit  150  as more air flows in through the intake port  142  and through the filter unit  150 . 
     The ledge  166  of the internal barrier  137  supports and retains the installed filter unit  150  in the airflow path. The aperture  141  is smaller in each dimension than the filter unit  150  so that the filter unit  150  fully covers the aperture  141 . The filter unit  150  is held in place against the internal barrier  137  by the filter door  134 . The filter unit  150  is thereby secured such that the airflow caused by the blower  118  during cleaning operations of the mobile cleaning robot  100  does not shift the filter unit  150  out of place or unseat the filter within the second volume  140 U. 
     The bin housing  131  may include guide features or structures that extend into the subchamber  140 U to guide and secure the filter unit  150  in the filter seat  143 . The guide structures may be ramped or wedge-shaped protrusions, for example. 
     In some implementations, the filter door  134  includes guide features or structures that extend down from the filter door and press against the filter unit  150  to further secure the filter unit  150  in place when the filter door  134  is secured in a closed position. The structures can be a molded portion of the filter door  134 . 
     If the filter unit  150  is unseated from the internal barrier  137  during cleaning operations, airflow may bypass the filter unit  150  though a gap between the filter unit and the internal barrier  137  and allow debris to enter the second volume  140 U and the blower  118 . 
     The filter unit  150  is removably disposed in the bin  130 . During initial set up of the robot  100  and/or thereafter it may be necessary or desirable to place, remove or replace the filter unit  150  in the bin  130 . To this end, the filter access door  134  can be opened and the filter unit  150  can be removed as described below. The filter removal procedure can be executed with the bin  130  removed from the support structure  102 , or with the bin  130  installed in the seating  120  and the bin access door  134  open. The filter unit  150  can be removed, cleaned of dust and debris, and reinstalled in the bin  130 , or the filter unit  150  can be replaced in the bin  130  with a new filter unit  150 . 
     The filter unit  150  can be accessed and handled as follows. For the purpose of description, the bin  130  is initially in the closed position with the door  134  closed and the filter unit  150  mounted in the installed filter seat  143  as shown in  FIGS.  5  and  7   . The closed door  134  holds the filter unit  150  and the arms  172  down against the biasing load of the springs  176 . In some embodiments, the rear, laterally extending leg of the flange  162  presses on the rear end of the filter unit  150  as shown in  FIG.  12   . 
     The filter access door  134  is then opened. When the door  134  is opened, the springs  176  force the arms  172  to automatically pivot in direction N ( FIG.  11   ) about the hinges H 1  into the extended position ( FIGS.  9 - 11   ). The filter unit  150 , being held in the filter loading seat  171 , is thereby likewise raised from an installed position to a raised position. The user can then conveniently grasp the filter unit  150  and lift or slide the filter unit  150  out of the filter loading seat  171 . The pull-tab  157  can be used to grasp and remove the filter unit  150  from the bin  130  through the filter door  134 . 
     The arms  172  will remain upright under the force of the springs  176 . The user can then place or slide a filter unit  150  (which may be the original filter unit or another filter unit) into the filter loading seat  171 . With the arms  172  in their upright position, the filter unit  150  thus supported is disposed in its filter loading position. The user can then push the filter access door  134  closed in a closing direction P ( FIG.  11   ). As the door  134  pivots closed, the door  134  (the flange  162  and/or the body panel  134 B) contacts an upper, front end leading edge  150 E of the filter unit  150  (e.g., the top edge of the frame rail  152 C) and transfers the closing force to the filter unit  150  at that engagement. The closing force is thereby transferred to the arms  172  via the filter unit  150 , causing the arms  172  to pivot downward (against the continuing load of the springs  176 ) in a direction Q ( FIG.  11   ) toward the retracted position as the door  134  is closed. The door  134  remains in contact with the filter unit  150  and is pivoted down in this manner until it is fully closed and latched, at which time the engagement between the door  134  and the filter unit  150  has forced the filter unit  150  into its fully installed position on the installed filter seat  143 . 
     In the event that the filter unit  150  is not fully seated in the filter loading seat  171 , the closing door  134  may push the filter unit  150  down into its fully inserted position on the filter loading seat  171 . As the door  134  is closed and the filter unit  150  and arms  172  are pivoted down, the lower end of the filter unit  150  is forced into a slot defined below the top wall  133 . In this way, the filter unit  150  is accurately positioned and secured in the installed filter seat  143  and relative to the aperture  141 . 
     Notably, as the door  134  is pivoted closed, the engagement between the filter unit  150  and the door  134  ensures that the interlock features  164  do not engage and interlock with the arms  172 . That is, the arms  172  are pushed downward at a rate that prevents interference between the ends of the arms  172  and the interlock features  164 . 
     If the robot  100  is operated with the filter unit  150  missing from the bin  130 , the airflow FP will not be properly cleaned and may damage the blower  118 . It is therefore important to ensure that the filter unit  150  is properly installed before operating the robot  100 . The filter presence system  160  provides a robust and effective mechanism for this purpose. 
     When the filter access door  134  is open without a filter unit  150  in the filter loading seat  171 , the arms  172  will remain upright under the force of the springs  176 , as shown in  FIGS.  13  and  15   . As the door  134  is rotated from the open position toward the closed position, the lower section  162 A of the flange  162  will pass between the arms  172  and into the recesses  174 . The stop wall  173  of each arm  172  will enter the slot  165  of the corresponding interlock feature  164 . 
     As the door  134  is further rotated toward the closed position, the stop wall  173  of each upstanding arm  172  is further received in its respective slot  165  until the terminal edge  173 A abuts the end wall  164 A, as shown in  FIGS.  16  and  17   . In some embodiments, the terminal edge  173 A is substantially parallel with the abutting face  164 A′ of the end wall  164 A so that the terminal edge  173 A fits substantially squarely with the end wall  164 A. 
     The stop walls  173  are thereby interlocked with the interlock features  164  to limit or prevent further pivoting of the door  134  toward the closed position. The cover  134  is retained in a locked open position and the filter presence system  160  has assumed a lockout position. The stop wall  173  in slot  165  arrangement of each arm interlock provides lateral stability to each arm  172  to ensure that the ends of the arms do not become disengaged from the features  164 . 
     As a result, the door  134  cannot be fully closed, and the user is thus notified that the filter unit  150  should be installed. The inability and failure of the door  134  to close completely provides visual and tactile feedback to the user indicating that the filter unit  150  is not installed. 
     Moreover, the bin access door  112  cannot be fully closed over the bin  130  with the door  134  not fully closed. In some embodiments, the robot  100  is configured such that the blower  118  will not operate when the door  112  is not closed. In some embodiments, the bin access door  112  must be closed to make contact with an electrical contact on the support structure, and the robot  100  may visually or audibly indicate an error to the user in the event an attempt to run the blower  118  is made while the bin access door  112  is open. Because the filter access door  134  cannot close, the bin access door  112  cannot close, and the robot  110  therefore cannot be run without the filter unit  150  probably installed. 
     In some embodiments, the relative positions, angles, orientations and/or geometries of the cover  134 , interlock features  164 , recesses  174 , stop walls  173 , and arms  172  are selected such that the arms  172  mechanically prevent or resist displacement of the cover  134  beyond the locked open position. In some embodiments, these components are arranged such that the force vector of the closing cover  134  tends to hold the arms  172  at their original angle or to raise the arms  172  further, and does not tend to force the arms  172  to pivot downward. 
     The user can rotate the filter access cover  134  back away from the arms, and load the filter unit  150  into the filter loading seat  171 . The user can then close the door  134  as described above. 
     The arms  172  are pivoted through an angle T ( FIG.  15   ) from their raised position ( FIG.  15   ) to their retracted position ( FIG.  8   ). In some embodiments, the angle T is at least 23 degrees. 
     In some embodiments, the filter unit  150  is disposed at an angle with respect to horizontal when fully installed in the installed filter seat  143 . In some embodiments, the filter unit  150  is disposed at an angle relative to horizontal in the range of from about 20 to 26 degrees. 
     The debris bin  130  is removable from the mobile cleaning robot  100 , for example, to be emptied of debris by a user, cleaned, and/or replaced. However, it is important that the bin  130  be properly seated in the seating  120  when the blower  118  is running in order to ensure that the air flow ports and passages are mated and aligned as prescribed. Also, the bin  130  should be retained in the seating  130  until deliberately removed by the user. The bin  130  should not become dislodged from the seating inadvertently if the robot  100  is turned upside-down, for example. 
     The bin retention system  180  serves to secure the bin  130  in the seating  120 . The bin retention system  180  also enables an operator to selectively remove the bin  130  from the seating  120  and replace and secure the bin  130  (or another debris bin  130 ) in the seating  120 . 
     In use, the bin  130  is inserted into the seating  120  in an insertion direction I ( FIG.  5   ), as discussed above. The bin  130  is oriented such that the latch portions  184  of the handle  149  align with the latch tabs  183  of the latch assemblies  186 A and  186 B, respectively. This alignment may be accomplished deliberately by the user and/or by the mechanical centering provided by the cooperating geometries of the bin  130  and the seating  120 . 
     The handle  149  may be in either a raised position or a retracted position when the bin is being inserted into the seating  120 . In either case, the latch tabs  183  will slide along the bin sidewall  138  and over the handle latch portions  184 . The girth and contours of the bin sidewall  138  may depress the latch members  187  outwardly to ease entry of the bin  130 , but the springs  188  continue to exert a return force. The rounded upper edges  183 B facilitate the passage of the latch tabs  183  over the sidewall  138  and latch portions  184 . If the handle  149  is in the retracted position, each latch tab  183  is forced into the space or socket  185 D above the land  185 A, thereby latching the bin  130  in the seating  120 . If the handle  149  is in the raised position, each latch tab  183  is forced into the socket  185 D or onto the ramp  185 B. The handle  149  is then lowered into the retracted position, causing the latch tab  183  to slide along the ramp  185 A and then drop into the socket  185 D above the land  185 A, thereby latching the bin  130  in the seating  120 . 
     With the bin  130  fully seated and the handle  149  in the retracted or stored position, each latch tab  183  extends laterally into the corresponding socket  185 D and is retained in this position by the biasing load of the spring  188 . The latch mechanisms  182 A,  182 B are in their locking positions, as shown in  FIGS.  20  and  21   . In the event a force is applied to the bin  130  tending to displace the bin  130  from the seating  120  (i.e., a force along the axis A-A in a removal direction R ( FIGS.  5  and  21   )), each latch tab  183  will engage and interlock with the land  185 A of its corresponding handle latch portion  184 . As a result, the bin  130  is prevented or inhibited by the interlocks between the lands  185 A and the latch tabs  183  from being displaced from the seating  120 . In some embodiments, the handle body  149 A is oriented substantially horizontal when the handle  149  is in its stored position. 
     The components of the bin retention system  180  are configured such that a force exerted on the raised handle  149  in the removal direction R primarily results in vertical lifting forces on the latch tabs  183  and not laterally directed forces that would push the latch tabs  183  outwardly (direction K) along the axes M-M. 
     The bin  130  may thereafter be removed or withdrawn from the seating  120  as follows. The user rotates the handle  149  in the direction F from the retracted position to the raised position. As the handle  149  is rotated, each latch portion  184  is correspondingly rotated in the direction F relative to its latch tab  183 . The interaction between each latch portion  184  and latch assembly  186 A,  186 B pair will be described below with reference to the latch mechanism  182 A as shown in  FIGS.  18 - 23   . However, it will be appreciated that this description likewise applies to the latch mechanism  182 B. In some embodiments, the handle body  149 A is oriented substantially vertical when the handle  149  is in the raised position. 
       FIGS.  20  and  21    show the bin  130  seated in the seating  120 , the handle  149  in the retracted position, and the latch mechanism  182 A in the locking position. As discussed above, the latch tab  183  is laterally extended by the spring  188  and seated in the socket  185 D. 
     As the user rotates the handle  149 , the latch features  185 A,  185 B are correspondingly rotated relative to the latch tab  183  about the hinge axis E-E. The flat  185 A is relocated and reoriented so that it no longer locks the latch tab  183  in place. The leading edge  185 C of the ramp  185 B slides to a position under the latch tab  183  along the removal axis R. The latch mechanism  182 A is thereby placed in a releasing position. 
     With the latch mechanism  182 A in the releasing position, the user then lifts the bin  130  in the removal direction R out of the seating  120 . 
     As the bin  120  is removed, the ramp  185 B progressively pushes the latch tab  183  outwardly against the force of the spring  188 . The latch tab  183  is thereby forcibly translated, depressed or displaced in the direction K into the hole  189 . The ramp  185 B holds the latch tab  183  in the depressed position, enabling the latch tab  183  to slide over the handle  149  and onto the bin sidewall  138 . The latch tab  183  can then slide along the bin sidewall  138  until the bin  130  is clear of the seating  120 . 
     The latch feature  185 B will displace the latch tab  183  outward a displacement distance V sufficient for the latch tab  183  to slide over the edge  138 A of the bin  130  below the latch portion  184  without undue effort. In some embodiments, the latch tab  183  is displaced in this manner such that the end face  183 A of the latch tab  183  is laterally clear or nearly clear of the edge  138 A. 
     In some embodiments and as shown in  FIGS.  18 - 23   , the ramp  185 B (or other latch feature(s) on the handle latch portion  184 ) is configured to not displace the latch tab  183  outward when the bin  130  is fully seated and the handle  149  is fully raised, the latch mechanism  182 A being in the releasing position. In this case, the leading edge  185 C is positioned below and adjacent the lower edge of the latch tab  183 . The latch tab  183  is then displaced the full distance V as the bin  130  is lifted out and the latch tab  183  slides down the ramp  185 B (which increases in height). 
     In other embodiments, the ramp  185 B (or other latch feature(s) on the handle latch portion  184 ) is configured to operate as a cam. As the user rotates the handle  149 , the leading edge  185 C of the ramp  185 B slides under the latch tab  183  and between the latch tab  183  and the interior of the bin  130 . The ramp  185 B thereby progressively pushes the latch tab  183  outwardly against the force of the spring  188  in the direction K and holds the latch tab  183  in a depressed position when the latch mechanism  182 A is in the releasing position and the bin  130  is still seated in the seating  120 . 
     In some embodiments where the ramp  185 B (or other latch feature(s) on the handle latch portion  184 ) is configured to operate as a cam, the ramp  185 B forces the latch tab  183  only a portion of the distance V when the bin  130  is fully seated and the handle is fully raised, placing the latch mechanism  182 A in the releasing position. The latch tab  183  is then displaced the remainder of the distance V as the bin  130  is lifted out and the latch tab  183  slides down the ramp  185 B. 
     In other embodiments where the ramp  185 B (or other latch feature(s) on the handle latch portion  184 ) is configured to operate as a cam, the ramp  185 B forces the latch tab  183  the full distance V when the bin  130  is fully seated and the handle is fully raised, placing the latch mechanism  182 A in the releasing position. 
     Once the bin  130  has been removed, the latch tab  183  is free to return to the extended position urged by the spring  188 . The bin  130  (or another debris bin) can thereafter be installed in the seating as described above. 
     The robot  100  may further include a bin detection system for sensing an amount of debris present in the debris bin  130  (e.g., as described in U.S. Patent Publication 2012/0291809, the entirety of which is hereby incorporated by reference). 
     In some implementations, the bin  130  is formed to fit in the seating  120  within a tolerance (in some embodiments, 0 mm to 5 mm). The tolerance ensures that the one or more ports of the debris bin  130  align with other features of the mobile cleaning robot  100  without adversely affecting airflow or allowing air leaks, as described below. 
     The bin  130  may be formed of any suitable material(s). Suitable materials may include rigid polymeric materials (e.g., plastic). 
     In some implementations, the bin  130  includes a transparent portion for viewing the containment volume  140 L to determine if the bin  130  requires emptying. In some implementations, one or more sensors placed within the debris bin  130  or at the opening of the debris bin  130  detect an approximate amount of debris in the debris bin  130  and send an alert to the mobile cleaning robot  100  that the bin  130  is in need of evacuation or emptying before proceeding with further operation (e.g., further vacuuming). 
     One or more bin sensors, such as optical sensors, can be used to measure approximately how much debris is accumulating in the first volume  140 L, and when the first volume  140 L is full of debris and should be emptied. A signal can be sent from the bin full sensor indicating this measurement to a controller or processor of the mobile cleaning robot  100 . In some implementations, the controller  198  can generate instructions to cease cleaning operations and cause the mobile cleaning robot  100  to navigate to an external evacuation device. In some implementations, the controller can generate a measurement on a graphical user interface of the mobile cleaning robot  100  or an associated remote device in communication with the mobile cleaning robot  100 , send an alert to a remote device, cause a beacon to light, or otherwise indicate to a user that the bin  130  of the mobile cleaning robot  100  should be emptied. 
     In some implementations, a bin access door position sensor  117 A is provided to indicate whether the bin access door  112  is closed or not. For example, the bin access door position sensor  117 A may be one or more electrical contacts on the robot  100  that are engaged or actuated by contact with one or more contacts or features  117 B on the bin access door  112  when the door  112  is closed. A signal from or actuation of the bin door position sensor  117 A can be used by a controller of the mobile cleaning robot  100  (e.g., the onboard controller  198 ) to determine whether the bin access door  112  is closed. If the bin access door  112  is not closed during a cleaning operation, the controller  198  will prevent the mobile cleaning robot  100  from operating at least certain components, subsystems or functions. In particular, the controller  198  may prevent at least the blower  118  (and, in some embodiments, at least the blower  118  and the drive system  194 ) from running even when a command is received (e.g., a command that is manually input via an HMI on the robot  100 , a command received via a remote application, or a command issued from an automatic scheduling routine). The controller  198  may actuate or send a signal or alert to the user indicating that there is an error associated with the bin  130 . Prompted by the alert, the user can inspect the robot  100  and ascertain the cause of the error (i.e., why the bin access door  112  is not closed). The user may determine that the bin  130  is not properly positioned or configured, and can reconfigure the bin  130  and close the bin access door  112  to enable the robot  100  to continue the cleaning operation. 
     Thus, the bin access door position sensor  117 A and the filter presence system  160  can cooperatively prevent undesirable operation of the robot  100  in the event a filter unit  150  is not properly positioned in the bin  130 . In that case, the filter presence system  160  will prevent the filter access door  134  from assuming its closed position, which will prevent the bin access door  112  from being placed in its closed position over the nonclosed bin  130  in the seating  120 . This in turn will cause the bin access door position sensor  117 A to indicate that the bin access door  112  is not properly positioned (i.e., it is not closed). With the robot  100  in this state, the controller  198  will prevent the robot  100  from operating at least certain subsystems or functions and may issue an alert, as discussed above. 
     In some implementations, a bin presence sensor  115 A is mounted in the bin access door  112  with a cooperating feature or component  115 B being mounted in or on the bin  130 . In some embodiments, the bin presence sensor  115 A is a Hall Effect sensor and the component  115 B is a magnet. A signal from the bin presence sensor  115 A can be used by a controller (e.g., the onboard controller  198 ) to determine whether the debris bin  130  is present inside the mobile cleaning robot  100 . If the debris bin  130  is not present in the bin seating  120  or is not properly positioned with the filter access door  134  closed during the cleaning operation, the controller  198  of the mobile cleaning robot  100  will prevent the mobile cleaning robot  100  from operating at least certain subsystems or functions as discussed above with regard to the sensor  117 A. The controller  198  may actuate or send a signal or alert to the user indicating that there is an error associated with the bin  130  as discussed above with regard to the sensor  117 A. 
     The robots described herein can be controlled, at least in part, using one or more computer program products, e.g., one or more computer programs tangibly embodied in one or more information carriers, such as one or more non-transitory machine-readable media, for execution by, or to control the operation of, one or more data processing apparatus, e.g., a programmable processor, a computer, multiple computers, and/or programmable logic components. 
     A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. 
     Operations associated with controlling the robots described herein can be performed by one or more programmable processors executing one or more computer programs to perform the functions described herein. Control over all or part of the robots and evacuation stations described herein can be implemented using special purpose logic circuitry, e.g., an FPGA (field programmable gate array) and/or an ASIC (application-specific integrated circuit). 
     Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only storage area or a random access storage area or both. Elements of a computer include one or more processors for executing instructions and one or more storage area devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from, or transfer data to, or both, one or more machine-readable storage media, such as mass PCBs for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Machine-readable storage media suitable for embodying computer program instructions and data include all forms of non-volatile storage area, including by way of example, semiconductor storage area devices, e.g., EPROM, EEPROM, and flash storage area devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. 
     In some embodiments, the robot  100  uses a variety of behavioral modes to effectively vacuum a working area. Behavioral modes are layers of control systems that can be operated in parallel. The robot controller  198  (e.g., microprocessor) is operative to execute a prioritized arbitration scheme to identify and implement one or more dominant behavioral modes for any given scenario, based upon inputs from the sensor system. The robot controller  198  may also be operative to coordinate avoidance, homing, and docking maneuvers with a dock. 
     Generally, the behavioral modes for the described robot  100  can be characterized as: (1) coverage behavioral modes; (2) escape behavioral modes, and (3) safety behavioral modes. Coverage behavioral modes are primarily designed to allow the robot  100  to perform its operations in an efficient and effective manner, while the escape and safety behavioral modes are priority behavioral modes implemented when a signal from the guidance system indicates that normal operation of the robot  100  is impaired (e.g., obstacle encountered), or is likely to be impaired (e.g., drop-off detected). 
     Representative and illustrative coverage behavioral modes (for vacuuming) for the robot  100  include: (1) a Spot Coverage pattern; (2) an Obstacle-Following (or Edge-Cleaning) Coverage pattern, and (3) a Room Coverage pattern. The Spot Coverage pattern causes the robot  100  to clean a limited area within the defined working area, e.g., a high-traffic area. In a certain embodiments the Spot Coverage pattern is implemented by means of a spiral algorithm (but other types of self-bounded area algorithms, such as polygonal, can be used). The spiral algorithm, which causes outward or inward spiraling movement of the robot  100 , is implemented by control signals from the microprocessor to the motive system to change the turn radius/radii thereof as a function of time or distance traveled (thereby increasing/decreasing the spiral movement pattern of the robot  100 ). 
     The foregoing description of typical behavioral modes for the robot  100  are intended to be representative of the types of operating modes that can be implemented by the robot  100 . One skilled in the art will appreciate that the behavioral modes described above can be implemented in other combinations and other modes can be defined to achieve a desired result in a particular application. 
     A navigational control system may be used advantageously in combination with the robot  100  to enhance the cleaning efficiency thereof, by adding a deterministic component (in the form of a control signal that controls the movement of the robot  100 ) to the motion algorithms, including random motion, autonomously implemented by the robot  100 . The navigational control system operates under the direction of a navigation control algorithm. The navigation control algorithm includes a definition of a predetermined triggering event. 
     Broadly described, the navigational control system, under the direction of the navigation control algorithm, monitors the movement activity of the robot  100 . In one embodiment, the monitored movement activity is defined in terms of the “position history” of the robot  100 , as described in further detail below. In another embodiment, the monitored movement activity is defined in terms of the “instantaneous position” of the robot  100 . 
     The predetermined triggering event is a specific occurrence or condition in the movement activity of the robot  100 . Upon the realization of the predetermined triggering event, the navigational control system operates to generate and communicate a control signal to the robot  100 . In response to the control signal, the robot  100  operates to implement or execute a conduct prescribed by the control signal, i.e., the prescribed conduct. This prescribed conduct represents a deterministic component of the movement activity of the robot  100 . 
     The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the invention.