Patent Publication Number: US-2023150150-A1

Title: Robot charging dock with illuminated charge connector

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. Design Pat. Application No. 29/815,913, filed Nov. 17, 2021, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to robot charging dock having a charge connector configured to mate with a charge port on a robot and more particularly to such a charge connector which is illuminated. 
     BACKGROUND ART 
     Autonomous mobile robots (AMRs) may be configured to automatically dock with a dedicated charging dock in order to keep the vehicle batteries charged and thus provide continuous operation without manual intervention. AMRs typically use multiple sensors to locate the charging dock and accurately mate a charge port on the robot with a charge connector on the charging dock to provide a path for electrical current to flow into and charge the robot&#39;s batteries. 
     The primary navigation sensor for a typical AMR is a laser range finding device (Lidar). However, Lidar device accuracy may not always be sufficient to accurately dock at a charging station. For this reason, a vision system (e.g. camera and computer software) is typically used as a secondary sensor to accurately locate and mate with the dock&#39;s charge connector. 
     In many cases, robots used in facilities are required to maintain a high state of charge overnight to offer full availability for first-shift operations. Facility lighting is often dimmed or dark during the overnight period. Thus, accurate docking of the AMR charging port to the charge connector of the charging station in low or no light using the vision camera can present serious challenges. As a result, there is a need to overcome the challenges of accurate docking with an AMR in low or no warehouse lighting. 
     SUMMARY OF THE EMBODIMENTS 
     In accordance with one embodiment of the disclosure, a robot charging dock is provided. The charging dock includes a charge connector configured to mate with a charging port of a mobile robot and a charge connector frame having a front surface on which the charge connector is mounted. The front surface has a first side edge and a second side edge and there is a front cover disposed over the charge connector frame and having an aperture through which the charge connector protrudes. There is at least a portion of the front cover spaced from the front surface of the charge connector frame, defining an internal region. There is an opening to the internal region formed along at least a portion of a perimeter of the aperture and a light source disposed in the internal region. The light source is directed toward the opening to allow the light source to illuminate charge connector. 
     In one or more embodiments the following features may be included. The light source may be positioned proximate one of the first side edge or the second side edge of the front surface of the charge connector frame. The light source may comprises a first light source positioned proximate the first side edge and a second light source positioned proximate the second side edge. The light source may comprises a plurality of LEDs positioned along a portion of one of the first side edge or the second side edge of the front surface of the charge connector frame and the plurality of light emitting diodes may be directed toward the opening to illuminate the charge connector. The first light source may comprises a first plurality of LEDs positioned along a portion of the first side edge of the front surface of the charge connector frame and the second light source may comprise a second plurality of LEDs positioned along a portion of the second side edge of the front surface of the charge connector frame. The first plurality of LEDs may be directed toward a first opening formed along a first portion of the perimeter of the aperture and the second plurality of LEDs may be directed toward a second opening formed along a second portion of the perimeter of the aperture. The light source may comprise a light pipe having an input side positioned proximate and facing the plurality of LEDs and an output side facing the charge connector. The first light source may comprise a first light pipe having an input side positioned proximate and facing the first plurality of LEDs and an output side facing the charge connector and wherein the second light source comprises a second light pipe having an input side positioned proximate and facing the second plurality of LEDs and an output side facing the charge connector. 
     In one or more embodiments the following additional features may be included. The plurality of LEDs may be disposed along an edge of a printed circuit board; and the printed circuit board may be mounted on a side surface of the charge connector frame with the plurality LEDs extending beyond one of the first side edge and the second side edge of the front surface. The light pipe may be mounted on the front surface of the charge connector frame with the input side extending along a portion of one of the first side edge and the second side edge of the front surface to align with the plurality of LEDs extending beyond one of the first side edge and the second side edge of the front surface. The first plurality of LEDs may be disposed along an edge of a first printed circuit board, wherein the first printed circuit board is mounted on a first side surface of the charge connector frame with the first plurality LEDs extending beyond the first side edge of the front surface. The second plurality of LEDs may be disposed along an edge of a second printed circuit board, and the second printed circuit board may be mounted on a second side surface of the charge connector frame with the second plurality LEDs extending beyond the second side edge of the front surface. The first light pipe may be mounted on the front surface of the charge connector frame with the input side extending along a portion of the first side edge to align with the first plurality of LEDs extending beyond the first side edge of the front surface. The second light pipe may be mounted on the front surface of the charge connector frame with the input side extending along a portion of the second side edge to align with the second plurality of LEDs extending beyond the second side edge of the front surface. The light pipe may be rectangular in shape and it may have a first side edge which extends along a portion of one of the first side edge and the second side edge of the front surface to align with the plurality of LEDs extending beyond one of the first side edge and the second side edge of the front surface. The light pipe may have a second side edge which is aligned with the opening to the internal region. The first light pipe may be rectangular in shape and a first side edge may extend along a portion of the first side edge of the front surface to align with the first plurality of LEDs extending beyond the first side edge of the front surface. The first light pipe may have a second side edge which is aligned with the first opening to the internal region and the second light pipe may be rectangular in shape and have a first side edge which extends along a portion of the second side edge of the front surface to align with the second plurality of LEDs extending beyond the second side edge of the front surface. The second light pipe may have a second side edge which is aligned with the second opening to the internal region. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing features of embodiments will be more readily understood by reference to the following detailed description, taken with reference to the accompanying drawings, in which: 
         FIG.  1    is a front and side perspective view of the robot charging dock according an embodiment of this disclosure; 
         FIG.  2    is a front and side perspective view of a portion of the frame of the robot charging dock of  FIG.  1    with the external cover removed; 
         FIG.  3    is an enlarged front perspective view of the charge connector frame shown in  FIG.  2   ; and 
         FIG.  4    is a top plan view of the printed circuit board shown in  FIGS.  2  and  3   , depicting the plurality of light emitting diodes thereon. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     The disclosure and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments, as the skilled artisan would recognize, even if not explicitly stated herein. 
     Descriptions of well-known components and processing techniques may be omitted to not unnecessarily obscure the embodiments of the disclosure. The examples used herein are intended merely to facilitate an understanding of ways in which the disclosure may be practiced and to further enable those of skill in the art to practice the embodiments of the disclosure. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the disclosure. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings. 
     The invention is directed to an electrical charging system for use in charging autonomous mobile robots (AMRs). Although not restricted to any particular AMR application, one suitable application that the charging dock may be used in is warehouse order fulfillment. The use of robots in this application will be described to provide context for the electrical charging system; however, the electrical charging system described herein is not limited to this application and it may be used in various applications of AMRs. 
     Referring to  FIG.  1   , a robot charging dock  100 , according to an aspect of this disclosure, is depicted. Charging dock  100  includes a charge connector  110  configured to mate with a charging port of an AMR (not shown) to enable the AMR to recharge when needed. It should be noted that functional and design aspects of charging dock  100  and charge connector  110  are merely exemplary and should not be considered limiting. 
     In many applications, including warehouse order fulfillment, AMRs are required to maintain a high state of charge overnight to offer full availability to first-shift operations. AMRs must autonomously navigate to and mate with the charging dock. The primary navigation sensor for a typical AMR is a laser range finding device (Lidar). However, Lidar device accuracy may not always be sufficient to properly dock at a charging dock. For this reason, a vision system (e.g. camera and computer software) is typically used as a secondary sensor to accurately locate and mate with the dock&#39;s charge connector. In warehouse order fulfillment, and other applications, lighting is often dimmed or dark during the overnight period. Thus, accurate docking of the AMR charging port to the charge connector of the charging station in low or no light using the vision camera can present a serious challenges. 
     In order to counter this, it was determined that lighting of the charge connector would be desirable to provide adequate contrast to the robot vision system when docking with the charging dock. However, the contrast-enhancing lighting must be reliable over the service life of the charging dock, it must not interfere with mating, and it must be unobtrusive under normal ambient lighting conditions. This disclosure provides an approach to lighting the charge connector which achieves the foregoing objectives. 
     Continuing to refer to  FIG.  1   , robot charging dock  100  includes an external cover, which may be made of a hard plastic, opaque material, which may comprise several cover components, including front cover  120 . Front cover  120  has an aperture  122  formed therein through which charge connector  110  protrudes. The aperture  122  exposes a portion of front surface  124  of charge connector frame  130  (shown in  FIG.  2   ). The charge connector  110  includes a base plate  126 , which is mounted onto front surface  124 . Between the front cover  120  and the front surface  124  of charge connector frame  130  there is an opening or gap extending along edges  127  and  128  of front cover  120  about the sides of aperture  122 , which allows light from a light source to emanate from an internal region and illuminate the portion of the front surface  124  visible in aperture  122  as well as the charge connector  110 . This will be described in more detail below. 
     Before describing the light source in the internal region, which is defined by the spacing between the inside surface of front cover  120  and the front surface  124  of charge connector frame  130 , certain other aspects of the exterior of charging dock  100  are described for completeness. Top cover  140  may include a user interface panel  142  disposed in a cavity in the surface of top cover  140 . The user interface panel may include certain indicators and controls for a user to operate the Charging dock  100 . For example, lighting signals to indicate various states such as “Ready”, “Charging”, “Power On”, “Recovery Mode”, and “Fault” may be included. A button to start a manual charge may also be included. 
     Along the back edge of top cover  140  is a back panel  150 , which comprises a center panel section  152  and side panel sections  154  and  156  on the left right sides, respectively, of center panel section  152 . Center panel section  152  has a rectangular front surface  158  which is substantially parallel to front cover  120 . Left side panel section  154  has a rectangular front surface  160  and right side panel section  156  has a rectangular front surface  162 . 
     Right and left side panels  154  and  156  sections have wide sidewalls  164  and  166 , respectively, on one side and converge to narrower widths on the other sides which interconnect with center panel section  152 . Thus, right and left side panel sections  154  and  156  are wedge-shaped. As a result, their front surfaces  160  and  162  are not parallel with front surface  158  of center panel  152  or front cover  120 . They are each disposed at an angle, θ, with respect to surface  158 . Fiducial markers (e.g. a 2-dimensional bar code) may be disposed on front surfaces  160  and  162 , respectively, and, as is known in the art, AMRs may use the angled fiducial markers for precision navigation during the process of docking with the charging dock The angled surfaces are used in conjunction with the Lidar to accurately locate the dock. The 2-D barcodes may be read by the cameras and used to identify the dock number in order to maintain robot order of charging/queuing at docks. The cameras may also be used for navigation by capturing the image of the rectangular outline of  126  charge connector. 
     Referring to  FIG.  2    there is shown a portion of metal frame  200  for robot charging dock  100  of  FIG.  1   . Metal frame  200  comprises charge connector frame  130 , which is connected to frame floor  202  at the front side of frame  200 . Front corner supports  204  and  206  are connected to frame floor  202  at each front corner of frame  200  and on either side of charge connector frame  130 . A rear frame element  208  spans the length of and is connected to the frame floor  202  along the back of the metal frame  200 . One rear corner support  210  is shown, but the other is omitted from this figure for clarity. There are front and rear floor mounts  212  and  214 , respectively, which are affixed to frame base  216 . Mounts  212  and  214  may be secured to the floor of the warehouse. 
     In addition to the charge connector  110 , the only other components shown in  FIG.  2    are power supply  220 , power outlet  222 , first light source  230  to the left of charge connector  110  and base plate  126 , and second light source  232  to the right of charge connector  110  and base plate  126 . Light sources  230  and  232  are used to illuminate charge connector  110 , base plate  126 , and the portion of front surface  124  of charge connector frame  130  which is visible through aperture  122 . This illumination improves the ability of the AMR&#39;s vision camera to detect and mate with charge connector  110 , especially during low or no light conditions within a facility. To further improve the illumination, front surface  124  may be painted with a light colored paint, e.g. white. 
     Referring to  FIG.  3   , first light source  230  is shown to include a printed circuit board (PCB)  300 , including a first plurality of LEDs (not shown in this figure) and second light source  232  is shown to include PCB  302  which includes a second plurality of LEDs (also not shown in this figure). First light source  230  also includes a light pipe  304  and second light source  232  includes a light pipe  306 . Both light pipes  304  and  306  are shown mounted on front surface  124  charge connector frame  130 . It should be noted that only a single light source need be used and that the one or more light sources may be disposed at various locations on/near surface  124  about the charge connector  110 . The embodiment with two light sources disposed on either side of the charge connector  110  is only an exemplary embodiment. 
     While the light pipes  304  and  306  may be of various shapes and sizes and mounted in a range of locations, they are exemplarily depicted as flat, rectangular, plastic light pipes mounted on either side of the charge connector  110  on front surface  124 . Each light pipe is lit on-edge using a PCB-mounted linear array of LED lamps. The light pipes and LEDs are arranged to fit under the front cover  120 , in an internal region  320 , defined between the front surface  124  of charge connector frame  130  and the interior surface of front cover  120  (not shown in this view). The light pipes provide for even illumination and accommodate mounting of the LEDs away from the charge connector  110  where convenient physical mounting space can be provided. Alternate embodiments of the light pipes allow the LED PCBAs to be placed behind bracket  330  instead at the sides. For example, the light pipes can be formed with a 90 degree bend, or could be cut at a 45 degree angle such that internal reflection directs incoming light at a 90 degree angle. 
     The first plurality of LEDs on PCB  300  are positioned along a portion of the first side edge  330 ,  FIG.  3   , of the front surface  124  and the second plurality of LEDs on PCB  302  are positioned along a portion of the second side edge  332  of the front surface  124 . The first plurality of LEDs are aligned with and facing a first side edge (or input)  340  of light pipe  304  and the second plurality of LEDs are aligned with and facing a first side edge (or input)  342  of light pipe  306 . In this embodiment, the LEDs are positioned along an edge of PCBs  302  and  304 , which PCB edges extend beyond the front surface  124  in the regions of front surface edges  330  and  332 . 
     In this way, the LEDs are directly facing the input sides  340  and  342  of light pipes  304  and  306 , respectively. It should be noted that the LEDs may be mounted/configured differently than depicted, as long as they are in internal region  320  and are directed to input light into the light pipes. There is shown in  FIG.  4   , a PCB such as PCBs  300 / 302 . These PCBs include a plurality of LEDs, i.e.  401 - 407 , disposed along an edge of the PCB. Different PCB configurations may be used having more or less LEDs and different configurations other than being disposed linearly along an edge. The LEDs may be controlled to turn on during low/no lighting conditions and turn off when there is sufficient light in the facility. Alternatively, the LEDs may remain on continuously to provide better contrast for robot vision systems in all lighting conditions. 
     With this embodiment, the first light pipe  304  has a second or output edge  350  facing a first side of charge connector  110  and the second light pipe  306  has a second or output edge  352  facing a second side of charge connector  110 . Therefore, the light from the first plurality of LEDs entering the first side edge (or input)  340  of light pipe  304  exits the second or output edge  350  and illuminates the first side of charge connector  110 . Therefore, the light from the second plurality of LEDs entering the first side edge (or input)  342  of light pipe  306  exits the second or output edge  352  and illuminates the second side of charge connector  110   
     While not required, the second/output edges  350  and  352  of light pipes  304  and  306 , respectively, may be aligned with complimentary edges of front cover  120 ,  FIG.  1   . In other words, the second side edge  350  of first light pipe  304  may be aligned with the edge  127  of front cover  120  and the second side edge  352  of second light pipe  306  may be aligned with the edge  128  of front cover  120 . As noted above, there is a gap or opening between front cover  120  and front surface  124  of charge connector frame  130  about portions of the aperture. For example, such a gap/opening would be present along edges  127  and  128  of front cover  120  to allow light from the light sources to pass and illuminate charge connector  110 . The light source(s) and the gap(s)/opening(s) may be located in different positions. 
     Various embodiments of the present invention may be characterized by the potential claims listed in the paragraphs following this paragraph (and before the actual claims provided at the end of this application). These potential claims form a part of the written description of this application. Accordingly, subject matter of the following potential claims may be presented as actual claims in later proceedings involving this application or any application claiming priority based on this application. Inclusion of such potential claims should not be construed to mean that the actual claims do not cover the subject matter of the potential claims. Thus, a decision to not present these potential claims in later proceedings should not be construed as a donation of the subject matter to the public. 
     The embodiments of the invention described above are intended to be merely exemplary; numerous variations and modifications will be apparent to those skilled in the art. All such variations and modifications are intended to be within the scope of the present invention as defined in any appended claims.