Patent Publication Number: US-2020299077-A1

Title: System and method for alignment of trailers to dock equipment

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional patent application No. 62/819,850 filed Mar. 18, 2019, in the U.S. Patent and Trademark Office, the contents of which are herein incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     1. Field 
     Aspects of the present disclosure generally relate to the technical field of mail and parcel processing techniques. 
     2. Description of the Related Art 
     Automatic unloading of parcels or articles from a container or trailer may be accomplished using an automated unloading apparatus. A known automatic unloading apparatus for use with a container or trailer includes for example a ramp and a conveyor. Multiple parcels are located on a base belt within the container or trailer, wherein the unloading apparatus is configured to move into an interior of the container or trailer for removing the multiple parcels. The unloading apparatus requires that the trailer is in alignment with dock equipment whenever the unloading apparatus enters or exits the trailer. However, the process of aligning the trailer and dock equipment for operations is manual and prone to human error. 
     SUMMARY 
     A first aspect of the present disclosure provides a system for alignment of a container or trailer to dock equipment comprising a vision system configured to provide visual representations of a section of a container or trailer, an automated unloading apparatus configured to move into an interior of the container or trailer, and a control system operably coupled to the vision system, the control system comprising at least one processor configured via computer executable instructions to receive the visual representations of the section of the container or trailer, interpret the visual representations of the section of the container or trailer, and output control commands for alignment of the container or trailer and the automated unloading apparatus. 
     A second aspect of the present disclosure provides a method for aligning a trailer or container to dock equipment comprising providing visual representations of a section of a container or trailer by a vision system, receiving and interpreting the visual representations of the section of the container or trailer by a control system, and aligning the container or trailer to dock equipment based on the visual representations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a schematic view of an automated unloading apparatus in accordance with an exemplary embodiment of the present disclosure. 
         FIG. 2  depicts a schematic view of a system for alignment of trailers to dock equipment in accordance with an exemplary embodiment of the present disclosure. 
         FIG. 3  depicts a flow chart of a method for aligning trailers to dock equipment in accordance with an exemplary embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     To facilitate an understanding of embodiments, principles, and features of the present disclosure, they are explained hereinafter with reference to implementation in illustrative embodiments. In particular, they are described in the context of being a system and method for aligning trailers or containers and dock equipment. Embodiments of the present disclosure, however, are not limited to use in the described systems or methods. 
     The components and materials described hereinafter as making up the various embodiments are intended to be illustrative and not restrictive. Many suitable components and materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of embodiments of the present disclosure. 
     Various disclosed embodiments include unloading items, such as for example parcels or packages, from a trailer or other container generally without operator intervention. An automated unloading apparatus is provided, wherein a nose ramp of the automated unloading apparatus is moved under a base belt in the trailer and under a first item of a plurality of items in the trailer. As the ramp continues advancing, the item is moved onto a conveyor, which is adapted to carry the item out of the trailer. In embodiments, a stack control curtain maintains the remaining items in a stack or pile during and after removal of the first item, and/or a tensioning mechanism maintains a desired tension on the base belt as the ramp moves under the base belt and the first item. 
       FIG. 1  depicts a schematic view of an unloading apparatus  100 , herein also simply referred to as unloader  100 , in accordance with an exemplary embodiment of the present disclosure. 
     A trailer  102  is positioned adjacent to a loading dock  104  and a dock door area  106  for unloading. In the trailer  102  are loaded items  108 , which are to be unloaded by the unloader  100 . The items  108  are positioned on top of a base belt  110 , a first end of which is attached to the trailer at an attachment point  112 . A second end of the base belt  110  (opposite to the first end) may be raised to a first transit position  114  to provide supported to stacked items during transit to help prevent stack collapse. The second end of the base belt  110  may alternately be placed in a second transit position (not shown in  FIG. 1 ) on the floor of the trailer  102 , where the base belt  110  may be rolled or gathered during transit. From either the first or second transit position, to initiate unloading of the trailer  102 , the second end of the base belt  110  is brought generally along the path indicated by the arrow  116  to be attached to the unloader  100 , as described in greater detail below. 
     The unloader  100  is positioned at the open door of the trailer  102  by an operator at an operator console  118 , also referred to as operator kiosk or station. The operator may use for example a video camera (not shown in  FIG. 1 ) that is mounted to the unloader  100  or to the loading dock  104  and presents the operator with a view of the unloader  100  and the trailer  102 . 
     The unloader  100  includes a positioning mechanism  120 , which is remotely operated by the operator to position the unloader  100  at the entrance to the trailer  102 . The positioning mechanism  120  may be a motorized caster or other mechanism suitable for positioning the unloader  100  relative to the trailer  102  prior to initiating an unloading process or during the unloading process. The positioning mechanism  120  is operable to position the unloader  100  at least along a longitudinal axis of the trailer  102  or horizontally relative to the trailer  102 . In some embodiments, the unloader  100  is substantially a same width as the interior of the trailer  102 , such that the unloader  100  substantially fills the trailer  102  from one sidewall to the other sidewall. 
     The unloader  100  moves into the trailer  102  along the trailer floor, sliding nose ramp  130  under the base belt  110  and under a rearmost item of the items  108 . By sliding the nose ramp  130  under an item  108  while the item  108  remains on the base belt  110 , the unloader  100  reduces the possibility of the nose ramp  130  pushing the items  108  into the trailer  102 , rather than sliding it up onto conveyor  126 . When moving forward, the unloader  100  moves at a speed that substantially matches a speed of a transport belt of the conveyor  126 . In this way, the items  108  are transferred with substantially no relative motion from the base belt  110  to the conveyor  126 . The unloader  100  may also include a stack control curtain  122  mounted to a positioning mechanism  124 . The unloader  100  is coupled to an extendible conveyor  126 , which is operable to carry items unloaded by the unloader  100  from the trailer  102 . A sensor  150  may be mounted in a position that enables the sensor  150  to sense items on the unloader  100  or the extendible conveyor  126 . The sensor  150  is operable to sense a label, RFID tag, barcode, or other identifying feature of such items. 
     Further embodiments of the unloader apparatus  100  are described for example in U.S. Pat. No. 8,651,794 B2 to Pippin and U.S. Pat. No. 9,738,466 B2 to Pippin which are incorporated by reference herein in their entirety. 
       FIG. 2  depicts a schematic view of a system  200  for alignment of trailers to dock equipment in accordance with an exemplary embodiment of the present disclosure. For an unloading operation as described for example with reference to  FIG. 1 , it is necessary that trailer or container  202  is in alignment with dock equipment, such as unloader  100 , of dock facility  208  whenever the unloader  100  enters or exits the trailer  202 . Further, the trailer  202  becomes lighter as the unloader  100  unloads the parcels and items (see items  108  in  FIG. 1 ) from an interior of the trailer  202  and causes the trailer  202  to rise in respect to the dock equipment, e.g. unloader  100 . When the unloader  100  tries to exit the trailer  202 , the previously set alignment needs correction. Currently, such an alignment is a manual process which is prone to human error. Thus, an improved alignment system  200  and method  300  are described which provide an automated alignment and/or alignment correction of the container  202  and unloader  100 . 
     In an exemplary embodiment, a system  200  for alignment of a container or trailer  202  to dock equipment comprises a vision system  210  configured to provide visual representations, of a section of a container or trailer  202 . The vision system  210  can be a monochrome vision system and can comprise for example one or more camera(s), such as one or more monochromatic camera(s)  212  providing images and/or video. In another embodiment, the vision can comprise one or more laser scanner(s) providing for example laser scanner images. Further, it should be noted that the vision system  210  can comprise many different imaging, scanning or monitoring systems as long as there are capable of providing images, video or visual representations of at least a section of the container or trailer  202 , such as for example LiDAR (Light Detection and Ranging) systems. 
     For example, the vision system  210  can be firmly mounted to the dock facility  208 , for example to a wall  204  of the dock facility  208 , using for example a mounting bracket  205 , and is pointed towards a specific section of the container or trailer  202 . However, the vision system  210  may be positioned or arranged at other locations, such as for example the automated unloading apparatus  100  or alignment equipment or at a place suitable for the vision system  210  to perform the described functions. During operation, the vision system  210  looks at and monitors the specific section, which is for example an upper rear section  206  of the container or trailer  202 . The section  206  is selected to minimize interference from movement or other objects below the section  206 , such as for example (human) operators and/or the unloader  100 . 
     The vision system  210  provides visual representations, such as images or video, of the section  206  of the container or trailer  202 . A control system  220  is operably coupled to the vision system  210 . The control system  210  comprises at least one processor  222  and is configured via computer executable instructions to receive and interpret the visual representations of the section  206  of the container or trailer  202 . This means that the control system  220  comprises software to interpret the visual representations provided by the vision system  210 . 
     The control system  220  is further configured to output control commands for alignment, for example to alignment equipment of the container or trailer  202  and/or dock equipment, such as the unloader  100 . For example, the at least one processor  222  can be configured to output the control commands. In another example, the control system  220  comprises a programmable logic controller (PLC)  224  that is programmed to receive input of the vision system  210  and to output control commands, e.g. to control alignment equipment. The PLC  224  can be part of the control system  220  or can be separately arranged within the system  220 . 
     The vision system  210  may be coupled via cables, i.e. wired, to the control system  220 . In other instances, the vision system  210  and the control system  220  may be coupled wirelessly, utilizing for example the Internet or other wireless communications networks. 
     A first alignment device  230  is assigned to the container or trailer  202 , such as for example a lift arranged to align the container or trailer  202  vertically along a vertical axis (z), see arrow  232 . The first alignment device  230  can be part of the container or trailer  202  or can be separate from the container or trailer  202 , for example a lift below the trailer  202  as illustrated in  FIG. 2 . 
     A second alignment device  240  is assigned to the unloader  100 . The alignment device  240  of the unloader  100  can be referred to as dock aligner and is used to align the unloader  100  at least along a longitudinal lateral axis (y) of the trailer  202  (horizontally relative to the trailer  202 ), see arrow  242 . The second alignment device  240  may also be referred to as positioning mechanism  120 , for example as described previously with reference to  FIG. 1 . The second alignment device  240  or positioning mechanism  120  may be a motorized caster or other mechanism suitable for positioning the unloader  100  relative to the trailer  202  prior to initiating an unloading process or during the unloading process. The second alignment device  240  may be part of the unloader  100  or can be separate from the unloader  100 . 
     In another embodiment, the alignment system  200  is configured such that the trailer/container  202  and dock equipment (unloader  100 ) can be aligned along multiple axes, such as vertical (z) and lateral (y) as described before, and along a longitudinal axis (x), see arrow  244 . Alignment along longitudinal axis (x) is used to ensure that the container or trailer  202  is close enough to the dock  209 , wherein the container/trailer  202  or the unloader  100  can be easily moved along axis (x) to provide proper alignment in this direction (x). 
     In another embodiment, the alignment system  200  can be configured such that the trailer/container  202  and dock equipment (unloader  100 ) can be aligned with respect to angles in terms of rotation about the axes x, y, z. Specifically, in addition to alignment along the axes x, y, z, angular alignment is also provided. Angular alignment refers to angles of rotation about the axes x, y, z. Rotation about the x-axis is referred to as rolling or tilting, rotation about the y-axis is referred to as pitching and rotation about the z-axis is referred to as yawing. The container/trailer  202  and/or unloader  100  are configured such that they can be aligned according to a tilt angle, a pitch angle or a yaw angle. In this case, the alignment equipment of the container/trailer  202  and/or the unloader  100  is/are configured to perform alignment according to tilt, pitch and yaw angle(s). This means that the alignment system  200  can provide alignment in 6 (six) directions (along axes x, y, z and tilt, pitch and yaw). Alignment can be performed by the container/trailer  202  alone, the unloader  100  alone or a combination of the container/trailer  202  and the unloader  100 . Further, it should be noted that the alignment devices  230 ,  240  are only shown schematically in  FIG. 2 . 
     The control system  220 , for example PLC  224 , is configured to output control commands to the first alignment device  230  (assigned to container or trailer  202 ) and/or second alignment device  240  (assigned to unloader  100 ) in order to change a vertical and/or horizontal position of the trailer  202  and/or the unloader  100 . Further, the control system  220  is configured to detect deviations or differences in multiple images or visual representations of the specific section, e.g. section  206 , of the trailer  202 . 
     When the vision system  210  comprise one or more camera(s)  212 , the vision system  210  provides a change in pixel position, regardless of what the vision system  210  sees. The system  200 , e.g. control system  220 , only needs to consider coordinated movement of most (majority of) pixels of the section  206  as representing actual movement. This acts as a filter for things that may momentarily move in a field of view of the vision system  210  (e.g. flying debris, human arms etc.). When the vision system  210  comprises for example one or more laser scanners, the one or more laser scanners create a point cloud (that act as pixels) and can provide a change in the point cloud. A point cloud as used herein is a set of data points produced by the laser scanner(s). 
     For example, the vision system  220  provides a first image and a second image of the section  206  of the trailer  202 , wherein the first image is different from the second image, for example comprises different pixel positions or comprises different point clouds. The control system  220  is adapted to recognize the difference and is programmed to restore or recover the first image by aligning the trailer  202  to a position corresponding to the first image of the trailer  202 . Thus, the control system  220  will output corresponding control commands or signals to the alignment equipment  230 ,  240  to align the trailer  202  and/or unloader  100  to the position corresponding to the first image. Alignment may be performed periodically or continuously. For example, alignment may be performed when differences along any of the axis x, y, z and angles roll, tilt, yaw are outside predefined thresholds. 
       FIG. 3  depicts a flow chart of a method  300  for aligning trailers to dock equipment in accordance with an exemplary embodiment of the present disclosure. The process or method  300  can be implemented by using any of the features, components, or devices discussed herein, or any combination of them. The method  300  is performed, for example, by a system  200  as disclosed herein, and under the control of its control system  220 . 
     While the method  300  is described as a series of acts that are performed in a sequence, it is to be understood that the method  300  may not be limited by the order of the sequence. For instance, unless stated otherwise, some acts may occur in a different order than what is described herein. In addition, in some cases, an act may occur concurrently with another act. Furthermore, in some instances, not all acts may be required to implement a methodology described herein. 
     The method  300  may start at  310  and may include an act  320  of providing visual representations of a section  206  of a container or trailer  202  by a vision system  210 . The method  300  may also include act  330  of receiving and interpreting the visual representations of the section  206  of the container or trailer  202  by a control system  220 , and an act  340  of aligning the container or trailer  202  to dock equipment based on the visual representations. At  350 , the method  300  may end. It should be appreciated that the described method  300  may include additional acts and/or alternative acts corresponding to features described with respect to the alignment system  200 . 
     In an embodiment, the method  300  further comprises detecting a deviation (difference) between a first visual representation and a second visual representation of a section  206  of the trailer or container  202 , wherein the aligning is based on the deviation between the first and second visual representations. 
     In another embodiment, the method  300  further comprises initially aligning the container or trailer  202  to the dock equipment according to a first position of the section  206  of the container or trailer  202 , providing a first visual representation of the section in the first position, providing a second visual representation of the section  206  in a second position, determining a difference between the first and second visual representations of the section  206 , and aligning the container or trailer  202  to the first visual representation and first position of the section  206 . 
     In an embodiment, the method  300  in combination with the system  200  can be configured as semi-automatic solution. In another embodiment, the method  300  and system  200  can be configured as fully automatic solution. 
     With respect to a semi-automatic solution, the step of initially aligning the container or trailer  202  to the dock equipment is performed for example by interfacing with a human operator. An operator initially aligns the trailer  202  to the dock equipment, remotely operating the alignment device  230 ,  240  and using the control system  220 . The operator sets an initial optimal alignment which is monitored by the vision system  210  and stored by the control system  220  as “optimal” or “ideal” position of the trailer  202  and dock equipment, e.g. unloader  100 . The initial alignment provides a visual representation or image of the section  206  the vision system  210  sees as ideal. Any variation is feedback for the alignment devices  230 ,  240  (lift or dock aligner of unloader  100 ) for automatic recovery of the ideal position initially stored. The semi-automatic solution requires an operator to initially set correct alignment. The initial setting is the reference that the vision system  210  attempts to keep steady. After initial alignment, the system  200  and method  300  perform alignment without interaction of the operator. 
     In another embodiment, the initial alignment is performed fully automated thereby providing a fully automated solution of alignment. For a fully automated solution, one or more reference marks, such as for example a sticker or paint, is/are added to a section of the trailer or container  202 . The reference mark(s) should not be added to doors of the trailer or container  202 , but for example to a section above the doors. The vision system  210  monitors the reference mark(s) located for example at section  206  and provides images or video of the reference mark(s). A reference mark is located a known distance vertically from dock  209  of the dock facility  208 , and a known distance horizontally from the center of the trailer  202 . This information is provided to the system  200 , specifically control system  220 , and the control system  220  uses this information in order to align the trailer or container  202 . The initial alignment as well as alignment performed during an unloading process is performed by the system  200  without interaction of an operator. 
     It should be appreciated that acts associated with the above-described methodologies, features, and functions (other than any described manual acts) may be carried out by one or more data processing systems, such as for example control system  220  via operation of at least one processor  222 ,  224 . As used herein, a processor corresponds to any electronic device that is configured via hardware circuits, software, and/or firmware to process data. For example, processors described herein may correspond to one or more (or a combination) of a microprocessor, central processing unit (CPU) or any other integrated circuit (IC) or other type of circuit that is capable of processing data in a data processing system. As discussed previously, the processor  330  that is described or claimed as being configured to carry out a particular described/claimed process or function may correspond to a CPU that executes computer/processor executable instructions stored in a memory in form of software and/or firmware to carry out such a described/claimed process or function. However, it should also be appreciated that such a processor may correspond to an IC that is hard wired with processing circuitry (e.g., an FPGA or ASIC IC) to carry out such a described/claimed process or function. 
     In addition, it should also be understood that a processor that is described or claimed as being configured to carry out a particular described/claimed process or function may correspond to the combination of the processor with the executable instructions (e.g., software/firmware apps) loaded/installed into a memory (volatile and/or non-volatile), which are currently being executed and/or are available to be executed by the processor to cause the processor to carry out the described/claimed process or function. Thus, a processor that is powered off or is executing other software, but has the described software installed on a data store in operative connection therewith (such as on a hard drive or SSD) in a manner that is setup to be executed by the processor (when started by a user, hardware and/or other software), may also correspond to the described/claimed processor that is configured to carry out the particular processes and functions described/claimed herein. 
     In addition, it should be understood, that reference to “a processor” may include multiple physical processors or cores that are configures to carry out the functions described herein. Further, it should be appreciated that a data processing system may also be referred to as a controller that is operative to control at least one operation. 
     It is also important to note that while the disclosure includes a description in the context of a fully functional system and/or a series of acts, those skilled in the art will appreciate that at least portions of the mechanism of the present disclosure and/or described acts are capable of being distributed in the form of computer/processor executable instructions (e.g., software and/or firmware instructions) contained within a data store that corresponds to a non-transitory machine-usable, computer-usable, or computer-readable medium in any of a variety of forms. The computer/processor executable instructions may include a routine, a sub-routine, programs, applications, modules, libraries, and/or the like. Further, it should be appreciated that computer/processor executable instructions may correspond to and/or may be generated from source code, byte code, runtime code, machine code, assembly language, Java, JavaScript, Python, Julia, C, C #, C++ or any other form of code that can be programmed/configured to cause at least one processor to carry out the acts and features described herein. Still further, results of the described/claimed processes or functions may be stored in a computer-readable medium, displayed on a display device, and/or the like.