Abstract:
To improve efficient use of robots in human-centric environments, robots have to overcome a number of challenges, including mobility challenges, physical interface challenges, self-maintenance challenges, security challenges, and safety challenges. These challenges can be overcome either by adding technology to a robot or by adding infrastructure to a robot&#39;s environment.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is a continuation of PCT International Patent Application No. PCT/US2013/066695 filed Oct. 24, 2013, which claims priority to U.S. Provisional App. No. 61/718,019, filed Oct. 24, 2012, both of which are herein incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates generally to the robotics field and more specifically to new and useful infrastructure for mobile robots. 
       BACKGROUND 
       [0003]    There is tremendous complexity and a number of challenges in operating robots in human-centric environments, e.g. office buildings, factories, and homes. Human functionality is difficult to replicate in robots. 
         [0004]    Thus, there is a need in the robotics field to create new infrastructure for robots in human-centric environments. New infrastructure for such purposes is desired. 
         [0005]    Robots in human-centric environments often have to overcome a number of challenges, including mobility challenges, physical interface challenges, self-maintenance challenges, security challenges, and safety challenges. These challenges can be overcome either by adding technology to a robot or by adding infrastructure to a robot&#39;s environment. Adding infrastructure to a robot&#39;s environment can be a one-time and/or incremental capital investment that can be amortized over many years and can support future upgrades as robot and sensor technologies evolve, possibly allowing multiple product generations of robots to be used simultaneously. Temporary and semi-permanent installations can be used for short-term deployments such as construction sites, rock concerts, sporting events, etc. 
       SUMMARY OF THE INVENTION 
       [0006]    Two of the major challenges faced by robots are mobility and sustainability. Mobility challenges can be solved by building infrastructure which can include buildings that can have door openers, special entrances, systems or structures for the robot to interact with that assist the robot to traverse between floors, navigation markers, and machine-readable tags. Mobility challenges can be solved by physical or virtual (software) enhancements to the robot, including mobility assistance devices, improved power management systems, card access systems, manipulator arms, sensors (optical, sonic, mechanical, etc.) and any other suitable robotic enhancements. Sustainability challenges, which can relate to keeping a robot operating in a continuous, self-sustaining mode (such that they may or may not require human maintenance/assistance to operate), can be solved by physical enhancements to the robot and/or building infrastructure, which can include charging stations, accessory changing stations, storage stations, security patrol stations/checkpoints, data transferring stations, repair stations, arming stations, waste removal stations, and cleaning stations. 
         [0007]    A robot beacon navigation system is disclosed. The system can include a building that has at least two robot navigation beacons and/or tags at different locations in the building. The building can have three or more beacons and/or tags. The system can have a server. The system can have a mobile robot configured to wirelessly communicate directly or indirectly with the server. The robot can be configured to receive a signal from the beacons and/or tags. The robot can be configured to send the signal received from the beacons and/or tags to the server. The server can be configured to send instruction data to the robot in response to the signal received from at least one of the beacons and/or tags. 
         [0008]    A method of controlling a mobile robot is disclosed. The method can include positioning the robot in a building have two, three, or more robot navigation beacons and/or tags at different locations in the building. The method can include transmitting beacon data from the beacons and/or tags to the robot. The method can include transmitting robot data from the robot to a server. At least a portion of the robot data can include at least some of the beacon data. transmitting instruction data from the server to the robot. 
         [0009]    A method of moving a robot through a doorway is disclosed. The method can include closing a door in the doorway. The door can have an upper partition and a lower partition. The method also can include opening the lower partition with the robot while the upper partition remains closed. The method can also include traversing the doorway with the robot. 
         [0010]    A door is disclosed. The door can have an upper partition and a rigid lower partition. The lower partition can be configured to rotate with respect to the upper partition. The door can have an actuator configured to unlock the lower partition, wherein the actuator is configured to be activated by a mobile robot. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0011]      FIGS. 1   a  and  1   b  are simplified views of a variation of the robotic system with the utility arm in retracted and extended configurations, respectively. 
           [0012]      FIGS. 1   c  and  1   d  are simplified views of a variation of the robotic system with the utility arm in various orientations. The utility arm is shown twice in both figures to illustrate its rotation. 
           [0013]      FIGS. 2   a  through  2   c  are partial views of variations of the robotic system with the utility arm in an extended configuration. 
           [0014]      FIGS. 3   a  and  3   b  illustrate a variation of the three-pronged gripping device in the closed and open configurations, respectively. 
           [0015]      FIGS. 4   a  and  4   b  illustrate a variation of the robotic system with the hooked arm in various configurations. 
           [0016]      FIG. 5  illustrates a variation of the building with automatic door openers. 
           [0017]      FIGS. 6   a  through  6   d  illustrate variations of a building with door adapters in an external configuration.  FIG. 6   d  is a cross-sectional view taken along the line X-X in  FIG. 6   a  and illustrates a variation of a building with door adapters in an internal configuration. 
           [0018]      FIG. 7   a  illustrates a variation of a building with robot door pulls.  FIG. 7   b  is an alternate view of the building with variations of the robot door pull. 
           [0019]      FIGS. 8   a  and  8   b  illustrate a variation of a building with robot doors embedded in existing doors. 
           [0020]      FIGS. 8   c  through  8   g  are variations of cross-sectional views taken along the line X-X in  FIG. 8   a  and illustrate variations of the embedded robot door. 
           [0021]      FIG. 8   h  is a variation of cross-sectional view taken along the line Y-Y in  FIG. 8   a  and illustrates a variation of the embedded robot door. 
           [0022]      FIGS. 9   a  and  9   b  illustrate a variation of a building with half doors having latches in external and internal configurations, respectively. 
           [0023]      FIG. 9   c  is a variation of a building with half doors. 
           [0024]      FIGS. 10   a  and  10   b  illustrate a variation of a building with separate robot doors. 
           [0025]      FIGS. 10   c  through  10   g  are cross-sectional views taken of a variation along the line X-X in  FIG. 10   a  and illustrate variations of the separate robot door. 
           [0026]      FIG. 10   h  is a cross-sectional view of a variation of a taken along the line Y-Y in  FIG. 10   a  and illustrates a variation of the separate robot door. 
           [0027]      FIGS. 11   a  and  11   b  illustrate a variation of a building with robot ramps and elevators. 
           [0028]      FIGS. 12   a  and  12   b  illustrate a variation of a building with one-way glass embedded in floor and ceiling tiles, respectively. 
           [0029]      FIG. 13   a  illustrates a variation of a building with robot cargo nets. 
           [0030]      FIGS. 13   b  and  13   c  are views of a variation of a building with variations of robot cargo nets. 
           [0031]      FIG. 14  illustrates a variation of the robotic system including tracks with climb assisting features. 
           [0032]      FIG. 15   a  illustrates a variation of the building with track systems. 
           [0033]      FIGS. 15   b  through  15   d  are views of variations of the building and variations of the track system for both internal and external use on a building. 
           [0034]      FIGS. 16   a  and  16   c  illustrate variations of a building with robot ramps between floors. 
           [0035]      FIG. 17   a  illustrates a variation of a building equipped with various robot navigation beacons and machine-readable tags. 
           [0036]      FIGS. 17   a - 1   a ,  17   a - 1   b ,  17   a - 2   a , and  17   a - 2   b  illustrate a variation of a robot equipped with variations of navigation beacon detectors. 
           [0037]      FIG. 17   b  illustrates a variation of a robot equipped with devices capable of reading machine-readable tags. 
           [0038]      FIG. 18  illustrates a variation of the robot charging station. 
           [0039]      FIG. 19   a  illustrates a variation of the building with the robot accessory changing station. 
           [0040]      FIG. 19   b  is an alternate view of the building with a variation of the robot accessory changing station. 
           [0041]      FIG. 20  is a schematic view of a variation of components in a robot navigation beacon. 
       
    
    
     DETAILED DESCRIPTION 
       [0042]    As shown in  FIG. 1 , a robotic system  10  can be equipped with a utility elongated rod, bar, or arm  30 . The robot system  10  can have a robot  20 . The robot  20  can have a body  24 . The robot  20  can have one or more front and rear flippers  22  having tracks and rotatably extending longitudinally away from the center of the body  24 . 
         [0043]    As shown in  FIGS. 1   a  and  1   b , the utility arm  30  can be telescoping and can be extended and retracted using an actuator, hydraulics, piezos, or any other suitable method of extending or retracting the arm  30 . The arm  30  can swivel on its base (i.e., where the arm connects to the body  24 ) to change the orientation of the utility arm  30  with respect to the robot  20  and can rotate about the longitudinal axis of the arm  30  to change the orientation of any devices attached to the arm  30 . 
         [0044]    As shown in  FIGS. 1   c  and  1   d , the utility bar  30  can be rotated (as shown by arrows) to manipulate (e.g., rotate and translate) objects in front of, behind, and on either side of the robot  20  and can be raised and lowered to manipulate objects at various heights. The utility arm  30  can be used to manipulate objects in the environment; for example, in a human-centric environment the arm  30  can be used to open doors, operate door-opening mechanisms, turn off light switches, push elevator buttons, and/or perform any other suitable function. The utility arm  30  can be made of hard plastic, steel, aluminum, carbon fiber, or combinations thereof. 
         [0045]    As shown in  FIGS. 2   a ,  2   b , and  2   c , a utility arm  30  can be equipped with one or more attachments that can provide additional functionality to the utility arm  30 . As shown in  FIG. 2   a , the attachment can include a manipulator device  40 , which can be used to manipulate objects in the environment; for example, in a human-centric environment the manipulating device  40  can be a hook and can be used to pull down on door handles, move furniture, unplug devices, type on a keyboard, pull a fire alarm, tow payloads, deliver dry cleaning, or combinations thereof. 
         [0046]    As shown in  FIG. 2   b , the attachment can include an access card or other key device  50 , which can be used to gain entry into controlled access areas. The robot system  10  can be configured to physically swipe the key device  50  through a card reader or against a card reader (for example, similar to a “key fob” device). The key device  50  may be a “smart key” device, such that a radio pulse generator in the key is recognized by an antenna in the access system or building. The access system may automatically unlock the door upon the robot  20  entering the area with the key device  50  or upon the robot pressing a button or pulling a lever while holding the key device  50 . The key device  50  may be built into the robot body  24  (e.g., not attached to the arm  30 ). 
         [0047]    The identification card  50  can be configured to be disabled if removed from the utility arm  30 , for example, to ensure that only certain robots have access to the controlled area. The access card or other key device  50  can be disabled when removed from the arm  30 . For example, the access card  50  can stop working when cut off from its power source, which can be connected through the arm  30 . The access card  50  can be disabled when removed from the proximity of a wireless authentication device, such as a Bluetooth device or a radio-frequency identification tag reader on a robot  20 , or when cut off from a power supply on a robot  20 , when removed from the proximity of a building, when removed from the proximity of a wireless network of a building, when cut off from a proximity sensor located on a robot  20 , when cut off from a decryption key provided by a computer or electronic circuit on a robot  20 , or combinations thereof. 
         [0048]    As shown in  FIG. 2   c , the attachment can include an identifier, such as a flag or pennant  60 , which can function to make humans aware of the robot, to identify and/or distinguish between robots having similar appearances, to differentiate between robots with different functionalities and features (e.g. cleaning robots and security robots), and to make the robot appear more human-friendly. For example, a human following up with a robot  20  at an event site can more easily distinguish robots by a number, name, color, or other identifier on a pennant  60 . The pennant  60  can be made of fabric, plastic, paper, rubber, or any other suitable material. A robot can also change the flag or pennants as the robot switches functionality (e.g., a security-indicating pennant when the robot is in a security mode, and a delivery-indicating pennant when the robot is in a delivery mode). An mobile device, such as a mobile phone, portable television, or tablet computer or laptop computer can be attached to the robot and can be used to identify the robot and provide 2-way communication with a user, operator, or other party (e.g., through the mobile device) that may be interfacing with the robot&#39;s environment. 
         [0049]      FIGS. 3   a  and  3   b  illustrate that the utility rod or arm  30  can be equipped with a gripping device  70 . The gripping device  70  can be used to manipulate objects in a human-centric environment, e.g. open doors. The gripping device  70  can include three prongs  71 ,  72 , and  73 , as shown in  FIG. 3   b . The prongs can be curved prongs  71 ,  72 , and  73 , and can be concave and/or spoon-shaped, square-shaped, triangular, convex, hexagonal, mated to a specific door knob, handle, or interface, or combinations thereof. The gripping device  70  can be made of a rigid material. The prongs can include a layer of protective material such as rubber, felt, or combinations thereof, for example, to prevent the gripper  70  from damaging objects, and to prevent objects in the environment from damaging the gripper  70 . The gripping device  70  can be opened, closed, and rotated about its own longitudinal axis using actuators, springs, or any other suitable method or combinations thereof for opening, closing, and twisting the gripping device  70 . The gripping device  70  can be used to manipulate objects in the environment; for example, in a human-centric environment the gripper  70  can be used to pull down on door handles, twist door knobs  311 , open containers, change light bulbs, operate water faucets, tighten and loosen screws, turn on lamps, change thermostat settings, reboot computers, install hot-swappable hard drives in a server, or combinations thereof. 
         [0050]    A robot  20  can be equipped with an second utility arm  80 , which can be a jointed arm and can be made of hard plastic, steel, carbon fiber, titanium, aluminum, or combinations thereof. As shown in  FIGS. 4   a  and  4   b , a robotic system  10  can have the arm  80 . The arm  80  can be a single rigid, semi-rigid, or flexible segment. The arm  80  can be comprised of two or more rigid segments connected by hinges, rotary joints, or any other suitable connectors. The segments can be controlled using actuators, hydraulics, or any other suitable method of controlling connectors. The appropriate length of each rigid segment in the jointed arm  80  can be calculated using the dimensions of a robot  20  and the width of the opening, but any suitable dimensions unrelated to the robot size can be used. For example, the arm and/or arm segments can be sized and configured to open a door and hold the door open a sufficient amount, such that the robot may pass through the open door without the arm blocking the robot&#39;s path. The hooking arm  80  can be used to manipulate objects in the environment; for example, in a building  300  including a door  310  located inside a wall  320 , the arm  80  can be used to hold doors open while humans and/or a robot  20  pass through. In a human-centric environment, the hooking arm  80  can be used to determine the position of a robot  20  relative to walls, doors, and other potential obstacles, push elevator buttons, and/or any other suitable function. 
         [0051]    As shown in  FIG. 5 , a building  300  can be equipped with automatic door openers  89 , which can be attached to existing doors  310  and can integrate into existing access control systems. An automatic door opener  89  can be made entirely for robots, such that humans cannot use the automatic door opener but a robot  20  can; alternatively, an automatic door opener can be made for both robot and human use. A robot  20  can use an automatic door opener  89  to open a door  310 ; for example, a robot  20  can press a push button, swipe a valid access card, use a wireless remote, or communicate with a remote human or robot server to open, close, lock, and unlock doors. 
         [0052]    As shown in  FIG. 6 , a building  300  can be equipped with door adapters  90 , which a robot  20  can use to manipulate a door  310  in a human-centric environment. As shown in  FIGS. 6   a ,  6   b ,  6   c , and  6   d , the door adapter  90  can include a robot interface  91  and connectors  92 ,  93 ,  94 ,  95 , respectively. The connectors may be external to the door, internal to the door, or a combination thereof. The robot interface  91  can be a push button, pin or wafer tumbler lock, combination lock, keypad, access card reader, magnetic lock, magnet, and/or any other suitable fastening device. The connector  92 ,  93 ,  94 ,  95  can be made of metal, chain, springs, and/or any other suitable material, and can function to connect the robot interface  91  to the latching mechanism on the door. As shown in  FIGS. 6   a ,  6   b ,  6   c  and  6   d , connectors  92 ,  93 ,  94 ,  95 , respectively, can be optimized for a variety of latching mechanisms, which can include a door knob  311 , a lever-operated handle  312 , a crash bar  313 , and a sliding latch, respectively. A robot  20  can use a handle adapter  90  to open doors; for example, a robot  20  can insert a matching key into the robot interface  91  and turn the key to pull down on the connector  92 ,  93 ,  94 ,  95 , which can apply a torque to the knob and unlatch the door. 
         [0053]    As shown in  FIGS. 7   a  and  7   b , a building  300  can be equipped with door pulls  100 , which a robot  20  can use to manipulate a door  310  in a human-centric environment. The robot door pull  100  can include a layer of protective material such as rubber, felt, or any other suitable material to prevent a robot  20  from damaging door. As shown in  FIGS. 7   a  and  7   b , the door pull  100  can include a magnet, hook, post, spring, or any other device that functions to keep a robot  20  in contact with a door  310 . A robot  20  can use a door pull  100  to push or pull doors; for example, a robot  20  can touch a magnet to a door pull  100  and pull the magnet away to open a door. A door pull  100  can be used in combination with a handle adapter  90  and/or a hooking arm  80 ; for example, a robot  20  can use a handle adapter  90  to unlatch a door, then use a door pull  100  to open the door, and then use a jointed arm  80  to hold the door open while the robot  20  passes through. 
         [0054]    A building can be equipped with robot doors that can be embedded in or attached to existing full doors in doorways and/or in walls. The doors can be made from wood, metal, plastic, fabric, or combinations thereof. Robot doors and door frames can be scaled to the size of robots, for example about 10 inches tall by about 20 inches wide, or more narrowly about 8 inches tall by about 16 inches wide, such that typical humans cannot enter through the door but a robot is able to enter. A human full door can be divided into one or more hinged partitions, for example, such that a robot can enter through a hinged lower partition of the full door, but the lower partition would be too small for a human to enter or at least significantly hinder the human trying to enter through the lower, robot partition. A garage-type door (e.g. a segmented door on a curved and/or straight track) driven by a motor or other actuator can have multiple settings to allow different types of entry. For example, a garage-type door can rise entirely for a human or automobile to enter and can also rise only 8 inches to allow a robot to enter. A robot can have access to control some or all of the open settings of such a garage door; for example, a robot can be cleared only to allow robot entry or can be cleared to allow both robot and human entry. A robot door can be opened and closed using actuators, hydraulics, magnets, or any other suitable method of opening and closing the door. In a human-centric environment, a robot can use a robot door to pass through doors and walls. 
         [0055]    As shown in  FIGS. 8   a  and  8   b , a robot door  110  can be embedded in a full door  310  and can hinge from one side or can be split in the lateral middle (e.g., with the split extending vertically) with hinges on both lateral sides of the door. The robot door  110  can have one or more panels at the terminal bottom of the full door  310 . The robot door  110  can be a lower partition of the full door  310 , and the remainder of the full door can be an upper partition of the full door  310 . The robot door  110  can be rigid or flexible. When the robot door  110  is opened, the robot can move through the opening, partially or completely traversing the plane of the full door  310 . 
         [0056]    As shown in  FIGS. 8   c  and  8   d , the robot door  110  can be embedded in a door  310  and can slide up into the door or down into the floor. As shown in  FIGS. 8   e  and  8   f , a robot door  110  can be embedded in a door  310  and can hinge from the door to open by swinging up or hinge from the floor to open by swinging down. As shown in  FIGS. 8   g  and  8   h , a robot door  110  can be embedded in a door  310  and can roll up or to the side. A robot  20  can use a robot door  110  to pass through doors without manipulating the latch on the existing door  310 ; for example, a robot  20  can press a push button to open a robot door  110 . 
         [0057]    The robot door  110  can be opened by an actuator receiving an “open” signal from a sensor sensing an encoded wired (e.g., by insertion of an access card into a card reader slot by the door)) or wireless signal, such as RF, Bluetooth, Wi-fi signals, or combinations thereof, emitted by the robot or an access card or chip on or held by the robot, or sent from a server caused by a communication from the robot (e.g., the robot sending the server the robot&#39;s coordinates causing the server to open the door). The actuator can unlock and/or open the robot door  110 . The actuator can lock and/or close the robot door  110  after the robot traverses the doorway and is clear of the robot door  110  (e.g., detected by an IR sensor) or when the robot sends a signal to close the robot door  110 . The upper partition can remain closed when the robot door opens  110 . 
         [0058]    As shown in  FIGS. 9   a  and  9   b , half doors and/or partial doors  120  can be built into existing doors  310  or installed into existing doorframes. The height of a half door  120  can be optimized for a robot  20 , and a sub-door  120  can include an external latching mechanism  121  or an internal latching mechanism  122 . A latching mechanism  121  or  122  can be a sliding lock, deadbolt, access card reader, and/or any other suitable latching mechanism. A partial door  120  can be equipped with a robot door handle or pull  100 . 
         [0059]    As shown in  FIG. 9   c , a robot  20  can use a partial door  120  to pass through doors without manipulating the latch on the existing door  310 ; for example, a robot  20  can push a sliding latch  121  in the appropriate direction to unlatch the partial door  120 . 
         [0060]    As shown in  FIGS. 10   a  and  10   b , separate robot doors  130  can be built into existing walls  320  and can hinge from one side or can be split in the middle with hinges on both sides. As shown in  FIGS. 10   c  and  10   d , a separate robot door  130  can be embedded in a wall  320  and can slide up into the wall or down into the floor. As shown in  FIGS. 10   e  and  10   f , a separate robot door  130  can be embedded in a wall  320  and can hinge from the wall to open by swinging up or hinge from the floor to open by swinging down. As shown in  FIGS. 10   g  and  10   h , a separate robot door  130  can be embedded in a wall  320  and can roll up or to the side. A robot  20  can use a separate robot door  130  to pass through walls without manipulating existing doors; for example, a robot  20  can insert a matching key into a separate robot door  130  and turn the key to unlatch the robot door  130 . 
         [0061]    A building can be equipped with one or more robot ramps and/or robot elevators to allow robots to work at a variety of heights in a human-centric environment. As shown in  FIG. 11   a , a robot ramp  138  can include an inclined plane and can be optimized for use with a piece of furniture or any other suitable object; for example, a robot  20  can drive up a robot ramp  138 , park on a table  331 , and perform tasks alongside human workers. As shown in  FIG. 11   b , a robot elevator  139  can include an appropriately-sized platform that can be raised and lowered using actuators, hydraulics, or any other suitable method of raising and lowering a platform. A robot can use a robot elevator  139  to change its elevation; for example, a robot  20  can drive onto the elevator  139 , raise the platform to a height above a table  331 , and make a visual recording of a business meeting. 
         [0062]    A building can be equipped with panels of glass, such as plexiglass, safety glass, window glass, one-way glass, mirrored glass, tinted glass, and/or any other suitable transparent material that can be installed in walls, ceilings, and/or floors and can allow a robot to traverse the building unhindered by obstacles presented by a human-centric environment. Glass tiles can be installed such that a robot can have access to the entire building or only certain areas. Glass tiles can enable a robot to record visually what is happening in an area while being possibly out of sight and can create the possibility that events happening an area will be recorded, which can affect employee and/or citizen behavior. Glass tiles can also allow robot operators to quickly observe a room (via the robot cameras) without needing to enter it. As shown in  FIG. 12   a , panels of one-way glass  140  can be embedded in floors and a robot  20  can drive in the space below the floor to perform security checks, maintenance tasks, and other activities without being seen. As shown in  FIG. 12   b , panels of safety glass  140  can be embedded in ceilings and a robot  20  can drive in the space above the ceiling. 
         [0063]    A building can be equipped with cargo nets, fences, scaffolding, ladders, trestles, and/or any other suitable material that can be attached to existing walls and can allow a robot to climb the building. Cargo nets can cover the entire exterior of a building or can partially cover a building, focusing on specific areas, and can provide optimum visibility for humans inside a building, allowing them to see through windows. As shown in  FIG. 13   a , cargo nets  148  can be designed to support a robot&#39;s weight but not a human&#39;s weight such that a robot can climb a cargo net  148  but even a small human cannot. As shown in  FIGS. 13   b  and  13   c , a building can be equipped with cargo nets  148  that are nearly vertical or cargo nets  148  that are angled with respect to to the building. A robot can use a cargo net  148  to climb a building, access the roof, perform security checks, and/or perform any other suitable task. 
         [0064]    A robot can be equipped with tracks, which can include climb assist functionality to assist a robotic system in climbing various objects. Climb assisting functionality can include hooking protrusions extending from a robotic system track that can grab and pull on an object and also allow a robot to drive regularly on a surface without damaging it. As shown in  FIG. 14 , hooking protrusions  149  can be optimized to grab the threads of a cargo net or wires of a chain-link fence  148 . A robot  20  can use tracks with hooking protrusions  149  to climb cargo nets  148 , ladders, rope ladders, scaffolding, fences, trestles, and/or any other suitable materials. 
         [0065]    As shown in  FIGS. 15   a  to  15   d , a building can be equipped with one or more robot track systems  150 , which can be attached to existing walls, floors, ceilings, and/or any other suitable objects or locations and can be made for internal or external use on a building. A track system  150  can include one or more parallel tracks  151  along which a robot  20  can travel and perform tasks. A track system can be encased in a clear tube, as shown in cross section in  FIGS. 15   c  and  15   d . In some embodiments, the tubes may be made of glass, plexiglass, hard plastic, or any other suitable material. As shown in  FIGS. 15   a ,  15   b , and  15   c , a robot  20  can use an external track system  150  to investigate reports of suspicious activity outside building entrances, collect current weather data, wash windows, record when personnel enter and leave the building, access the roof, and/or any other suitable task. As shown in  FIG. 15   d , a robot  20  can use an internal track system  150  to monitor building cleanliness, wash windows, record conferences, convey inter-building messages and deliveries, guide visitors to their destinations, and/or any other suitable task. As shown in  FIG. 15   d , the track may be elevated above the ground. In some embodiments, the tracks (and tubes) may run through walls and up and down levels, thus obviating the need for special robot doors, ramps, elevators, or other access devices and systems. Alternatively, a building can be equipped with one or more vertical and/or horizontal ladders and a robot can use hooked tracks  149  to climb along the ladders. 
         [0066]    As shown in  FIGS. 16   a - 16   c , a building can be equipped with one or more robot ramps  160 , which a robot  20  can use to traverse between floors. As shown in  FIG. 16   a , a robot ramp  160  can be built into an existing wall  320  such that humans cannot access the ramp  160  but robots can. A robot ramp  160  can include openings  161 , which can be robot doors  130  and can include any suitable latching mechanism. As shown in  FIGS. 16   b  and  16   c , a ramp  160  can be circular and can be optimally sized for a robot  20  to prevent or at least hinder use by humans. 
         [0067]    A building can be equipped with robot navigation radio signal emitters or beacons and/or one or more machine-readable inductive or passive signal tags (e.g., RFID tags), which can be attached to objects or locations such as existing doors, existing walls, wall supports, ceiling tiles, underneath floor tiles or carpeting, inside power outlets or conduit, on windows, inside HVAC vents, inside lights, inside network or communication boxes, inside baseboards or crown molding, inside furniture, inside file cabinets, on industrial shelving, inside waste receptacles, or combinations thereof. Protective material can be used on a robot and/or a building, wall, floor, ceiling, door and/or furniture to prevent scuffs and other damage to the robot and/or building, wall, floor, ceiling, door and/or furniture as a robot navigates around a building, and navigation beacons or tags can be embedded within or printed on the protective material, such as a baseboard. As shown in  FIG. 17   a , a building  300  can be equipped with robot navigation beacons that can provide a robot  20  with information. For example, the information can be for determining current location, direction of travel, an upcoming obstacle and/or turn in a hallway, speed of movement of the robot, the strength of beacon batteries, or combinations thereof. 
         [0068]    Robot navigation beacons can include radio frequency emitters at known locations and a robot  20  can use trilateration, triangulation, and/or other suitable methods to calculate its position. For example, a navigation beacon can be a cellular base station  170 , a radio broadcasting station  171 , a GPS satellite, and/or any other suitable emitter. The robot navigation beacons can be passively emitting Radio Frequency Identification (RFID) tags, or any other suitable passively enabled circuit that requires an antenna to receive an electromagnetic signal and power the circuit, and or re-transmit a response signal. 
         [0069]    As shown in  FIG. 17   a , robot navigation beacons can include sonic emitters and a robot  20  can use sonar to calculate its position; for example, a navigation beacon can be an infrasonic emitter  172 , an ultrasonic emitter  173 , and/or any other suitable sonic emitter. 
         [0070]    As shown in  FIG. 17   a , robot navigation beacons can include wireless access points and a robot  20  can measure the received signal strength to calculate its position; for example, a navigation beacon can be a wireless router  174 , a Bluetooth device, a cellular communications tower, a computer with a wireless Bluetooth or WiFi connection, a wireless repeater, a  3 G/ 4 G/LTE radio modem, any type of wireless sensor, laser signals, fiber optics, and/or any other suitable device that provides a wireless connection to a wired network. 
         [0071]    As shown in  FIG. 17   a , robot navigation beacons can include light emitters and a robot  20  can use one or more suitable methods to calculate its position; for example, a navigation beacon can be a visible light emitter, an infrared (IR) emitter  175 , and/or any other suitable light emitter. 
         [0072]    The robot can be equipped with one or more devices that can detect robot navigation beacons and can include antennas, ultrasonic sensors, WiFi radios, Bluetooth radios, cameras, IR detectors, and/or any other suitable sensor. As shown in  FIGS. 17   a - 1  and  FIG. 17   a - 2 , a robot  20  can be equipped with one or more sensor arrays  178 , which can include one or more IR detectors  179  and/or any other suitable device, and can be used to enable direction sensitivity. For example, as shown in  FIG. 17   a - 1   a  and  FIG. 17   a - 1   b , a robot  20  can be equipped with a horizontal circular sensor array  178  that can include three or more IR detectors  179 - 1 ,  179 - 2 ,  179 - 3 . As the robot  20  moves, different pairs of IR detectors  179 - 1 ,  179 - 2 ,  179 - 3  will detect wall-mounted robot navigation beacons  175 - 1 ,  175 - 2 ; the robot can use this information to determine its position and direction of travel. As another example, as shown in  FIG. 17   a - 2   a  and  FIG. 17   a - 2   b , robot navigation beacons  175 - 3 ,  175 - 4  can be mounted on the ceiling  330  and a robot  20  can be equipped with a vertical circular sensor array  178 . The robot can be equipped with a camera and can use machine vision to process visual information on a navigation beacon, which can include QR odes, arrows, or other coded visual cues that can direct a robot to turn left, slow down, turn right, watch for other robots crossing, or any other suitable operating instruction. 
         [0073]    A robot can use a combination of data from imaging devices, navigation beacons, and/or diagrams of a building to generate a real-time map of a building as it patrols the building performing tasks. A robot can use this technique of simultaneous localization and mapping to avoid obstacles and/or log data that might be important to humans occupying the building; for example, a robot can generate a real-time map of a hallway, compare the current map to a previous map of the hallway, and immediately notice an object on the ground or an area roped off for construction or remodeling. The robot can then avoid the obstacle, capture an image of the object, and relay the image to a remote human who can identify the object and give the robot further instructions. 
         [0074]    A robot&#39;s interaction with navigation beacons can be recorded on a server. The robot can move from beacon to beacon according to a route command from the server. For example, the robot  20  can detect robot navigation beacons  175 - 1 ,  175 - 2 , and this interaction can be transmitted by the robot or the beacon to the server, and analyzed and recorded on a server. The robot can send additional robot performance, audio, video, environmental, and location data to the server optionally along with beacon data transmitted to or sensed by the robot from the beacon. The beacon can transmit data to the server optionally along with robot data transmitted to the beacon. The server can then send (i.e., wired or wirelessly transmit) command or instruction data to the robot, for example, instructing the robot to move to beacon  175 - 4 , replace the battery in beacon  175 - 2 , empty the garbage bin in a nearby room, perform another task, or combinations thereof. 
         [0075]      FIG. 20  illustrates that the robot navigation beacons can have one or more visible or infrared lights  250 . The lights can turn on to indicate that a robot is nearby. The beacon lights  250  can be used in emergency situations to guide humans toward a building exit. 
         [0076]    Robot navigation beacons can be powered using a power source  252  such as one or more batteries, AC power from the wall, and/or any other suitable power supply. The beacons can be turned on and off by the server depending on whether or not there is a robot in the area. For example, if there are no robots in an area surrounding a beacon, a server can turn the beacon off to conserve power. The server can communicate over a wireless or wired connection with the beacon. Beacons can have a wake-on activity function to conserve power. For example a robot can transmit a wakeup signal to all beacons in the vicinity, and the beacons can be awakened and respond with location information, and/or other operating instructions. 
         [0077]    The beacons can have a CPU and/or MCU  254 , a radio  256 , a robot detector  258 , and an emitter  260 . The radio  256  can be configured to communicate with the server and/or the robots. Signals and power between the components on the beacon can travel in the directions shown by the arrows in  FIG. 20 . 
         [0078]    As shown in  FIG. 17   a , a building  300  can be equipped with one or more machine-readable tags that can provide a robot  20  with information for performing security checks, safety checks, maintenance tasks, and self-sustainability tasks, and which can include door type, room number, location, when the garbage was last emptied, and the size and layout of a room. Machine-readable tags can provide inputs to the robot, such as instructions for actions, identifications of people or objects, or any other suitable input. Machine-readable tags can include emitters and a robot  20  can receive a signal; for example, a machine-readable tag can be a laser/infrared emitter  181 , a sonic emitter  182 , and/or any other suitable emitter. (As used herein, beacons can merely be tags.) 
         [0079]    As shown in  FIG. 17   a , machine-readable tags can include displays of encoded information and a robot  20  can process the displayed image; for example, a machine-readable tag can be a quick response (QR) code  183  and/or any other suitable display of encoded information. 
         [0080]    As shown in  FIG. 17   a , machine-readable tags can include devices that store passive identifications linked to a database and a robot  20  can associate the stored identifications with corresponding entries in the database; for example, a machine-readable tag can be a radio-frequency identification (RFID) tag  184 , a barcode  185 , and/or any other suitable device that stores information. 
         [0081]    As shown in  FIG. 17   b , a robot  20  can be equipped with one or more devices  186  that can read information from machine-readable tags and can include infrared detectors, QR readers, RFID readers, and barcode scanners. 
         [0082]    A building can be equipped with one or more robot battery charging stations, which can be disguised to look like cabinets, bookshelves, lockers, furniture, and/or any other suitable object. As shown in  FIG. 18 , a robot charging station  190  can include an entrance and exit ramps  191  and  193 , which can be made of hard plastic, metal, and/or any other suitable material. A robot battery charging station  190  can include a robot battery charger  192 , which can be simple, fast, inductive, solar, USB-based, or any other suitable type of battery charger. A robot  20  can use a charging station  190  to recharge its battery; for example, a robot  20  can drive up the entrance ramp  191 , settle into an appropriate position above an inductive charger  192 , and drive down the exit ramp  193  when its battery is fully charged. 
         [0083]    Alternatively, a robot can be equipped with a solar charger and can park in a designated sunlit area to recharge; for example, a robot can park outside of the building, on the roof, on a balcony, next to an open window, or in any other suitable location. 
         [0084]    Alternatively, robot batteries can be mechanically swapped out and charged separately, or a non-rechargeable battery can be replaced, and a robot can make sure it has enough batteries in a battery magazine. In a situation where a battery magazine runs low, a robot can phone in an order for more batteries from a supplier or human maintenance worker and possibly receive the batteries from a shipping service or human worker and restock the battery magazine by itself. 
         [0085]    A building can be equipped with one or more robot accessory changing stations, which can be disguised to look like cabinets, bookshelves, lockers, furniture, and/or any other suitable object. As shown in  FIGS. 19   a  and  19   b , a building  300  can be equipped with a robot accessory changing station  200 , which can allow a robot  20  to adapt its functionality with different payloads  202 . A robot accessory changing station  200  can contain one or more accessories  202 , which can include a utility arm  30 , jointed arm  80 , access cards, keys, and magnets. A robot payload station  200  can include a waste receptacle  203  where a robot  20  can empty trash cans and vacuum bags. A robot payload station  200  can include a robot cleaning system  204  and a robot  20  can drive through a robot cleaner  205  to be cleaned. A robot payload station  200  can include a robot battery charger  192 , and a robot  20  can park near an inductive charger to recharge its battery. Alternatively, a payload station  200  can include a magazine of robot batteries and a robot  20  can exchange and/or replace its battery. 
         [0086]    Robots, elements, and methods described in U.S. Pat. No. 8,100,205, issued Jan. 24, 2012 and U.S. patent application Ser. No. 13/740,928, filed Jan. 14, 2013 are incorporated by reference herein. 
         [0087]    As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications, changes and combinations of disclosed elements and methods can be made to the variations disclosed without departing from the scope of the disclosure.