Load handling device having assigned code

Abstract

1. A load handling device for lifting and moving containers stacked in a grid storage structure having a track system, the load handling device configured to travel on the track system, the load handling device comprising a transmitter configured to transmit data and a receiver configured to receive data from the transmitter, the load handling device being assigned a code such that the transmitter is configured to transmit the code along with the data and the receiver is configured to discard received data that does not comprise the code.

Description

[Technical field]

[0001] The present invention relates to the field of load handling equipment, in particular to a load handling equipment for lifting and moving containers in a grid storage structure. [Background technology]

[0002] Some commercial and industrial activities require a system that allows for the storage and retrieval of a large number of different products. WO2015 / 185628A describes a storage and fulfillment system in which a stack of storage containers is arranged in a grid storage structure. The containers are accessed from above by a load handling device operating on top of the grid storage structure.

[0003] A given load handling apparatus lifts a target container from the top of the stack, which typically contains inventory items required to fulfill a customer order. The load handling apparatus typically comprises multiple parts, including a body for housing various components of the load handling apparatus, and a gripping apparatus for engaging the target container. Communication between the various parts of the load handling apparatus may be required, and to enable this, a transmitter is located in one part of the load handling apparatus and a receiver is located in another part. For successful communication to take place between the required parts, a communication signal from the required transmitter needs to be received by the receiver. However, interference between the transmitter and receiver may prevent the receiver from receiving the required communication signal. This is exacerbated in systems where multiple transmitters are provided, which increases the risk of interference and crosstalk.

[0004] It is against this background that the present invention was conceived. Summary of the Invention

[0005] In a first aspect, there is provided a load handling apparatus for lifting and moving containers stacked in a grid storage structure having a track system, the load handling apparatus being configured to run on the track system, the load handling apparatus comprising: a transmitter configured to transmit data; and a receiver configured to receive data from the transmitter; The load handling equipment is assigned a code such that the transmitter is configured to transmit the code along with the data and the receiver is configured to discard received data that does not include the code.

[0006] By assigning a code to a load handling apparatus such that the transmitter is configured to transmit a code (i.e., the assigned code) along with the data and the receiver is configured to discard data received if it does not have this code (i.e., if the code is not received along with the data), data from a certain transmitter (e.g., of another load handling apparatus) will not be recognized by the receiver and therefore will not be read by the receiver (or will be read as noise by the receiver). The code may therefore be recognizable between the transmitter and the receiver of the load handling apparatus. This advantageously prevents crosstalk and interference from other data sources that may be present (e.g., from other transmitters or transmitters of other load handling apparatus). The above apparatus may ensure that only data that needs to be read by the receiver is recognized by the receiver. Preventing or reducing crosstalk and interference to the load handling apparatus is particularly advantageous in cases where the data signal from the transmitter may be weak (e.g., the transmitter may be far from the receiver) and / or where the transmitter may be configured to be moved away from the receiver such that the data signal from the transmitter may be weak.

[0007] The transmitter and receiver may be configured to communicate via wireless communication, e.g., optical communication. The transmitter may be configured to transmit an optical transmission. The transmitter may be an optical transmitter that transmits data in the form of an optical signal, e.g., Visible Light Communication (VLC), Li-Fi, Irda, Optical Wireless Communication (OWC), or Reasonable Optical Near Joint Access (RONJA). The transmitter may be a light emitting diode (LED). The receiver may be configured to receive the optical transmission. The receiver may be a light detector or photo detector that may detect an optical transmission (i.e., an optical signal) from the transmitter. Communication from the transmitter to the receiver may depend on the light intensity and / or blinking of the transmitter.

[0008] The transmitter may comprise a unidirectional transmitter configured to transmit directly to the receiver, or an omnidirectional transmitter configured to transmit signals in multiple directions or over an angular range around the transmitter, for example, 10°, 45°, 90°, 180°, or 360° around.

[0009] The receiver may include a lens to focus a data signal (eg, an optical signal) from the transmitter onto the receiver.

[0010] The load handling equipment may be assigned a code generated using code division multiple access (CDMA). This may ensure that the receiver can only correlate data received from transmitters that are assigned the same code as the receiver. The transmitter may be configured to send its data modulated by the assigned code. For example, the code may be a vector made up of 1's and -1's, or 1's and 0's, or chips, and for each bit of data sent by the transmitter, the data may be modulated by the code assigned to the load handling equipment (e.g., the transmitter may blink for each element of the vector). In turn, the receiver may generate the vector code (or a copy of the vector code) assigned to the load handling equipment (and sent by the transmitter), allowing the receiver to correlate the data received by the transmitter. The receiver may correlate the data received by the transmitter by multiplying the received data with its own copy of the vector code. When the receiver is configured to correlate the data received by the transmitter, the value obtained by the multiplication may be a positive number (e.g., a relatively large positive number), whereas if the receiver is unable to correlate the data received by the transmitter (e.g., the receiver and the transmitter do not belong to the same load handling apparatus), the value obtained by the multiplication may be a negative number (e.g., a relatively large negative number compared to the positive number obtained during a successful correlation, or if the obtained value is close to zero, no data was received). In this way, the receiver may correlate the data received by the transmitter or may discard data that does not comprise a code. This may be done so that the receiver may recognize whether the data received is from a transmitter of the same load handling apparatus. The receiver may be configured to correlate the data received by the transmitter such that the receiver is configured to recognize only data received from a transmitter that has been correlated with the data of its transmitter. For example, the receiver may be configured to recognize only data received from a transmitter that belongs to the same load handling apparatus.

[0011] The load handling equipment may be assigned a unique code. The unique code may be assigned to the load handling equipment during manufacture of the load handling equipment.

[0012] The grid storage structure may accommodate containers stacked in a stack, where a track system may be disposed above the stack of containers. The load handling equipment may be configured to lift and move the containers. In particular, the load handling equipment may be configured to move containers from the top of the stack and / or drop containers onto the top of the stack. The track system may be disposed in a grid pattern above the stack of containers. The track system may comprise a plurality of grid cells. Each grid cell may be assigned a predefined code that may be assigned to a load handling equipment. The load handling equipment may be configured to move (i.e., travel) to a particular grid cell (i.e., a predefined grid cell location) on the track system. In particular, the load handling equipment may be configured to move on the track system to a predefined grid cell location such that the load handling equipment may retrieve a container from the top of the stack or a different location or drop a container onto the top of the stack or a different location. The load handling equipment may be configured to travel on the track system to a predefined grid cell location, where a code assigned to the grid cell location may be assigned to the load handling equipment (e.g., when the load handling equipment is stopped or parked at the predefined grid cell location to pick up or drop off a container). Thus, the code assigned to the load handling equipment may depend on the grid cell location of the load handling equipment. The load handling equipment may move to a new (i.e., different) grid cell location (e.g., to pick up or drop off a container from a different stack). The load handling equipment may be assigned a new code, i.e., the code assigned to the new grid cell location of the load handling equipment. In particular, the load handling equipment may be configured to move to a first predefined grid cell location where the load handling equipment may be assigned the code assigned to the first predefined grid cell location. The load handling equipment may be configured to move (e.g., subsequently move) to a second predefined grid cell location where the load handling equipment may be assigned the code assigned to the second predefined grid cell location.Each time a load handling apparatus moves to a different grid cell location, the load handling apparatus may be assigned a code that is allocated to the load handling apparatus's new grid cell location.

[0013] The load handling apparatus may include a communication interface configured to assign a code from an external communication manager. The code may be assigned to the load handling apparatus once it is stopped or parked at a predetermined grid cell location, i.e. the communication interface may be configured to assign the code to the load handling apparatus once it is stopped at a predetermined grid cell location. The code may be assigned to the load handling apparatus before it arrives or stops / parks at the predetermined grid cell location, for example once the communication manager determines the predetermined grid cell location for the load handling apparatus or once the communication manager commands the load handling apparatus to move to the predetermined grid cell.

[0014] The load handling apparatus may include a vehicle body and a gripping device. The load handling apparatus may include a drive mechanism operatively arranged to move the load handling apparatus on the grid storage structure. The load handling apparatus may include a container lifting assembly configured to raise and lower the gripping device relative to the body and for raising and lowering the container. The gripping device may be configured to be moved away from the body (e.g., lowered) to a fully lowered position (e.g., when the gripping device is lowered onto the container and may engage the container to be lifted, or when the gripping device is sufficiently lowered to lower the container to its intended location). The gripping device may be configured to be returned (e.g., raised) or moved back to the vehicle body to a fully raised position (e.g., when the gripping device is above the track system (e.g., within the body) and / or when the gripping device is lifted to receive the container within the body). Thus, the gripping device may be moved between a fully raised position and a fully lowered position. The receiver may be coupled to the body, i.e., provided on the body. The transmitter may be coupled to, i.e., provided on, the gripping device. The transmitter may be configured to transmit information from the gripping device. The transmitter may be configured to transmit information about the gripping device (e.g., when the gripping device is moved away from the body or lowered away from the body, and when the gripping device is moved back to the body or raised back to the body). For example, the transmitter may communicate or send data to the receiver regarding the status of the gripping device, whether it is engaged or disengaged with the container, the position of the gripping device (e.g., between its fully raised position and its fully lowered position), and / or the speed at which the gripping device is moving (e.g., when the gripping device is lowering or raising), etc.

[0015] The load handling apparatus may include a controller, which may be connectable to the receiver and / or the transmitter. The controller may be provided on the load handling apparatus (e.g., on the body of the load handling apparatus) and configured to control (i.e., provide instructions to) the operation of the body and / or the gripping device. The controller may be configured to interpret data received by the receiver and, based on the data, determine information about the body or the gripping device. In embodiments in which the transmitter is coupled to the gripping device, the controller may be connectable to the receiver and may be configured to interpret data received by the receiver and, based on the data, determine information about the gripping device based on the data, including, for example, the position of the gripping device (e.g., between a fully raised position and a fully lowered position), whether the gripping device has engaged and / or disengaged with a container, the speed at which the gripping device is moving, etc. Based on the received information, the controller may be configured to provide instructions to the body and / or the gripping device, including, for example, controlling the speed of the gripping device as it moves, commanding the gripping device to engage or disengage with a container, etc.

[0016] The receiver may be coupled to the gripping device (i.e., provided on the gripping device) and the transmitter may be coupled to the body (i.e., provided on the body). This may be alternative to or in addition to the transmitter on the gripping device and the receiver on the body, as described above. In these embodiments, the controller may be connectable to the receiver on the gripping device and configured to interpret data received by the receiver and determine information about the body based on this data. The transmitter on the body may also be configured to send information and / or commands to the receiver on the gripping device, such as instructing the gripping device to engage or disengage the container. The transceiver may be coupled to the body (i.e., provided on the body) and a further transceiver may be coupled to the gripping device (i.e., provided on the gripping device).

[0017] The load handling apparatus may include a power source (e.g., a battery) for powering the load handling apparatus (e.g., to power a receiver, a transmitter, and / or a controller, etc.). The power source may be provided on the body (e.g., a battery mounted on the body) and configured to power components within the body and / or components of the gripping apparatus. As an alternative or in addition to a power source provided on the body, a power source may be provided on the gripping apparatus (e.g., a battery mounted on the gripping apparatus) and configured to power components of the gripping apparatus and / or components within the body. The load handling apparatus may include a power cable connecting the power source in the body to the gripping apparatus, the power cable being configured to provide power from the power source in the body to the gripping apparatus (e.g., to power a transmitter mounted on the gripping apparatus).

[0018] The receiver and transmitter of the load handling device may be configured to be synchronized with each other so that data from the transmitter can be received and correlated by the receiver. For example, the receiver may be configured to check or sample the data sent by the transmitter when the transmitter sends its data, i.e. at the same time as the transmitter sends its data. The receiver may be configured to generate an assigned code when the transmitter sends its data (to correlate the data received by the transmitter). The receiver and transmitter may each comprise respective clocks that may be synchronized with each other so that the receiver may generate an assigned code at the same time as the transmitter sends its data. The receiver clock and the transmitter clock may be configured to be synchronized and / or resynchronized when the gripping device is returned to the body (e.g. once the gripping device is raised and recoupled with the body or once the gripping device is returned to the fully raised position). This advantageously provides an efficient way of ensuring and maintaining synchrony between the receiver and transmitter and maintaining synchrony between the receiver and transmitter without requiring complex or sensitive clocks that may automatically maintain synchrony. The receiver clock and the transmitter clock may be configured to be synchronized and / or resynchronized each time the gripping device is returned or recoupled to the body. The control device may be configured to synchronize the receiver clock and the transmitter clock.

[0019] In some embodiments, the receiver and transmitter may not require a clock to maintain synchronicity between the receiver and transmitter. The receiver may be configured to generate the code multiple times as the transmitter sends its data. If the receiver generates the code asynchronously with the code received from the transmitter, the receiver and transmitter may result in no or low correlation, preventing the receiver and transmitter from locking onto each other (i.e., the receiver cannot recognize the code from the transmitter). The receiver may ignore the data received from the transmitter and may not forward the data for further processing (e.g., by a controller). The receiver may be configured to continue generating the code and cycling through the code starting at different points along the vector code. For example, the receiver may generate a code that is transposed or shifted (e.g., by one chip) along the vector code, i.e., the receiver may start generating the code one chip after where it generated the code in the previous cycle. The receiver may be configured to continue generating the code until it is synchronized (i.e., aligned) with the code sent by the transmitter (assuming the transmitter is sending the same code). The codes may be configured to be synchronized or aligned when the receiver code and the transmitter code start and end with the same chip number, where each chip in the receiver code is mirrored by each chip in the transmitter code (i.e., the codes are correlated). The receiver and transmitter may be highly correlated and may lock onto each other (i.e., the receiver recognizes the code from the transmitter). The receiver may retain the data received from the transmitter and may forward the data for further processing (e.g., by a controller).

[0020] In another aspect, a system is provided comprising: a grid storage structure for accommodating containers stacked in a stack, the grid storage structure comprising a track system arranged in a grid pattern comprising a plurality of grid cells; A plurality of load handling apparatus as described above.

[0021] By providing a system having multiple load handling apparatuses, where each load handling apparatus is assigned a code, this advantageously prevents crosstalk and interference between the load handling apparatuses, i.e., from the transmitters of other load handling apparatuses in the system. The code assigned to each load handling apparatus may be recognizable between the transmitters and receivers of the same load handling apparatus. The above communication system may ensure that only data that needs to be read by the receiver of a given load handling apparatus is recognized by the receiver. Preventing or reducing crosstalk and interference between load handling apparatuses is particularly advantageous in systems with multiple load handling apparatuses, each having their own transmitters and receivers, particularly where the data signal from the transmitter may be weak and / or where the transmitter may be configured to be moved away from the receiver such that the data signal from the transmitter may be weak.

[0022] The system may include a communications manager that may be configured to define and manage codes that are assigned to load handling devices (e.g., each load handling device). Each grid cell may be assigned a predefined code that may be assigned to a load handling device.

[0023] As described above, the load handling equipment may be configured to travel (i.e., drive) on the rail system to a particular grid cell (i.e., a predetermined grid cell location). Each load handling equipment may be configured to drive on the rail system to a predetermined grid cell location, where a code assigned to the grid cell location may be assigned (i.e., is assigned respectively) to each of the load handling equipment.

[0024] The code for each grid cell may be unique, i.e., the code assigned to a load handling equipment may be unique to each load handling equipment. In other embodiments, the code for each grid cell may be locally unique, i.e., the code for a given grid cell may differ from the code in adjacent grid cells. The adjacent grid cell locations may include 1, 2, 3, 4, 5, 6, or more grid cells from the given grid cell location.

[0025] At least one of the codes assigned to the grid cells may be repeated across the grid cells. For example, the codes assigned to the grid cells may be repeated across the grid cells in any direction (i.e., XY direction), every other cell, or every 2, 3, 4, 5, 6, or more cells. Thus, the codes may be recycled (i.e., used more than once) across the grid cells of the storage structure. This advantageously reduces the total number of codes required to cover the grid cells (e.g., all grid cells) in the storage structure. This may be possible because the signal (i.e., signal strength or signal strength) from the transmitter may decrease or attenuate as the distance from the transmitter increases. Thus, crosstalk between the load handling devices may travel only a limited distance. The signal from the transmitter may travel a maximum distance (i.e., maximum crosstalk length). Beyond the maximum crosstalk length, the signal from the transmitter may not be received by the receiver. This allows the codes to be reused. The codes may be reused every twice the maximum crosstalk length across the grid cells. The codes assigned to the grid cells may repeat in a pattern (e.g., the same pattern) across the grid cells. A set number of unique codes may be assigned to the grid cells in a pattern (i.e., a pattern of codes). The pattern of codes may be repeated across the grid cells. For example, a set of nine unique codes assigned to nine grid cells in a 3×3 block of grid cells may be repeated in every 3×3 block of grid cells. This further reduces the total number of codes needed to cover the grid cells (e.g., all grid cells) in the storage structure.

[0026] In another aspect, there is provided a method for controlling a load handling apparatus, the method comprising the load handling apparatus described above, the method comprising: A step of assigning a code to the load handling equipment is included.

[0027] In another aspect, there is provided a method for controlling a system, the method comprising the system described above, the method comprising: assigning a code to each grid cell; and assigning codes to load handling equipment traveling on the track system.

[0028] The method may comprise the step of allocating a unique code to each grid cell. The method may comprise the step of allocating the same code to at least two of the grid cells. The method may comprise the step of allocating a plurality of codes to the grid cells in a pattern across the grid cells. The method may comprise the step of assigning a code to the load handling apparatus once the load handling apparatus is parked at a given grid cell location. The method may comprise the step of assigning a code allocated to a first grid cell location to the load handling apparatus parked at the first grid cell location. The method may comprise the step of assigning a code allocated to the second grid cell location to the load handling apparatus once the load handling apparatus moves to and parks at a second grid cell location. As each load handling apparatus moves to a new grid cell location, the method may comprise the step of assigning a code allocated to the new grid cell location to the load handling apparatus.

[0029] Aspects and example embodiments of the present invention will now be described with reference to the accompanying drawings. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a schematic perspective view of a grid storage structure and container. [Diagram 2] FIG. 2 is a schematic top view of the track system on top of the storage structure of FIG. [Diagram 3] FIG. 3 shows a load handling device on top of the storage structure of FIG. [Figure 4] FIG. 4 is a schematic perspective view of the load handling apparatus with the lifting assembly in a lowered configuration. [Diagram 5] FIG. 5 shows a schematic cutaway view of the load handling apparatus of FIG. 4 with the lifting assembly in a raised and lowered configuration. [Figure 6]FIG. 6 shows a schematic front view of a load handling device having an embodiment of a communication system. [Figure 7] FIG. 7 shows a schematic front view of a load handling apparatus having another embodiment of a communication system. [Figure 8] FIG. 8 shows a schematic top view of a grid storage structure having grid cells and a schematic diagram of codes assigned to the grid cells of the storage structure. [Figure 9A] FIG. 9A shows a schematic diagram of the code sent by the transmitter and received by the receiver when there is low correlation between the transmitter and receiver and no lock. [Figure 9B] FIG. 9B shows a schematic diagram of the code sent by the transmitter and received by the receiver when there is high correlation and lock between the transmitter and receiver. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] 1 illustrates a storage structure 1 comprising upright members 3 and horizontal members 5, 7 supported by upright members 3. The horizontal members 5 extend parallel to each other and to an illustrated x-axis. The horizontal members 7 extend parallel to each other and to an illustrated y-axis and transverse to the horizontal members 5. The upright members 3 extend parallel to each other and to an illustrated z-axis and transverse to the horizontal members 5, 7. The horizontal members 5, 7 form a grid pattern.

[0032] FIG. 2 shows an enlarged plan view of a section of a track system 13 forming part of and located on top of the horizontal members 5, 7 of the storage structure 1 illustrated in FIG. 1. The track system 13 may be provided by the horizontal members 5, 7 themselves (e.g. formed in or on the surface of the horizontal members 5, 7) or by one or more additional components attached to the top of the horizontal members 5, 7. The illustrated track system 13 comprises an x-direction track 17 and a y-direction track 19, i.e. a first set of tracks 17 extending in the x-direction and a second set of tracks 19 extending in the y-direction transverse to the tracks 17 in the first set of tracks 17. The track system 13 is arranged in a grid pattern comprising a plurality of grid cells 15, i.e. the tracks 17, 19 define openings in the center of the grid cells. The storage containers 9 are arranged in stacks 11 below the grid cells 15 defined by the grid pattern, with one stack 11 of containers 9 per grid cell 15. The grid cells 15 are sized to allow a container 9 located below the grid cell 15 to be lifted and lowered through the opening. The x-direction tracks 17 are provided in pairs separated by channels 21, and the y-direction tracks 19 are provided in pairs separated by channels 23. Other arrangements of the track system may be possible.

[0033] Figure 3 shows multiple load handling devices 31 moving on top of the storage structure 1 illustrated in Figure 1. The load handling devices 31, which may also be referred to as robots or bots, are provided with a set of wheels for engaging with corresponding x-direction tracks 17 or y-direction tracks 19 to enable the bots 31 to travel across the track system 13 and reach a particular grid cell 15. The illustrated pair of tracks 17, 19, separated by channels 21, 23, enable the bots 31 to occupy (or pass each other on) adjacent grid cells 15 without colliding with each other.

[0034] 4, the load handling apparatus 31 comprises a body 33 having one or more components therein or attached thereto that enable the load handling apparatus 31 to perform its intended functions. These functions may include traveling across the storage structure 1 on the track system 13 and raising or lowering containers 9 (e.g., to or from stacks 11) so that the load handling apparatus 31 may retrieve or drop off containers 9 at the location of a particular grid cell 15.

[0035] The illustrated load handling apparatus 31 includes a first set of wheels 35 and a second set of wheels 37 that are attached to the body 33 of the load handling apparatus 31 and enable the load handling apparatus 31 to move in the x and y directions along the tracks 17 and 19, respectively. In particular, two wheels 35 are provided on a short side of the load handling apparatus 31 that is visible in FIG. 4, and two additional wheels 35 are provided on an opposite short side of the load handling apparatus 31 (not visible in FIG. 4). The wheels 35 engage the tracks 17 and are rotatably attached to the body 33 of the load handling apparatus 31 to enable the load handling apparatus 31 to move along the tracks 17. Similarly, two wheels 37 are provided on a long side of the load handling apparatus 31 that is visible in FIG. 4, and two additional wheels 37 are provided on an opposite long side of the load handling apparatus 31 (not visible in FIG. 4). The wheels 37 engage the track 19 and are rotatably mounted to the body 33 of the load handling apparatus 31 to enable the load handling apparatus 31 to move along the track 19 .

[0036] The load handling apparatus 31 also comprises a lifting mechanism 39 configured to raise and lower the container 9. The illustrated lifting mechanism 39 comprises four tethers 41, which are connected at their lower ends to the gripping apparatus 100. The tethers 41 may be in the form of cables, ropes, tapes, belts, seat belts, or any other form of tether having the necessary physical properties to lift the container 9. The gripping apparatus 100 comprises at least one gripper assembly configured to engage features of the container 9. For example, the containers 9 may be provided with one or more openings on their upper sides through which the gripper assemblies may engage. Alternatively or additionally, the gripper assemblies may be configured to hook under a rim or lip of the container 9 and / or to clamp or grasp the container 9. The tethers 41 may be wound up or unwound to raise or lower the gripping apparatus 100 as required. One or more motors or other means may be provided to effect or control the winding up or down of the tethers 41.

[0037] As seen in Figures 5A and 5B, the body 33 of the illustrated load handling apparatus 31 has an upper portion 45 and a lower portion 47. The upper portion 45 is configured to house one or more operating components (not shown). The lower portion 47 is disposed below the upper portion 45. The lower portion 47 comprises a container receiving space or cavity for accommodating at least a portion of the container 9 raised by the lifting mechanism 39. The container receiving space is sized such that the container 9 can fit sufficiently within the cavity to allow the load handling apparatus 31 to move across the track system 13 at the top of the storage structure 1 without the bottom surface of the container 9 getting caught on the track system 13 or another portion of the storage structure 1. Once the load handling apparatus 31 reaches its intended destination, the lifting mechanism 39 controls the tether 41 to lower the gripping apparatus 100 and the corresponding container 9 out of the load handling apparatus cavity and to the intended location. The intended location may be a stack 11 of containers 9 or an exit point of the storage structure 1 (or an entrance point of the storage structure 1 if the load handling apparatus 31 moves to collect containers 9 for storage within the storage structure 1). In the illustrated example, the upper portion 45 and the lower portion 47 are separated by a physical partition, although in other embodiments the upper portion 45 and the lower portion 47 may not be physically separated by a particular component or portion of the body 33 of the load handling apparatus 31.

[0038] To remove a container from the top of the stack 11, the load handling apparatus 31 is moved in the X and Y directions as necessary so that the lifting mechanism 39 is positioned above the stack 11. The gripping apparatus 100 is then lowered vertically in the Z direction until it reaches its fully lowered position (shown in FIG. 5B) and engages the container 9 at the top of the stack 11. The gripping apparatus 100 engages or grips the container 9 and is then pulled upwards by the tether 41 with the container 9 attached. Once the gripping apparatus 100 reaches its fully raised position (shown in FIG. 5A), the container 9 is housed within the body 33 and held above the level of the tracks 17, 19. The load handling apparatus 31 can be moved to different positions in the XY plane, carrying the container 9 with it, in order to transport the container 9 to another location.

[0039] The container receiving space of the load handling apparatus 31 may not be within the body 33 of the load handling apparatus 31. For example, the container receiving space may instead be adjacent to the body 33 of the load handling apparatus 31, for example in a cantilever configuration where the weight of the body 33 of the load handling apparatus 31 is balanced with the weight of the container to be lifted. In such an embodiment, the frame or arms of the lifting mechanism 39 may project horizontally from the body 33 of the load handling apparatus 31, and the tethers 41 may be arranged at respective locations on the projecting frames / arms and configured to be raised and lowered from those locations to raise and lower the container into the container receiving space adjacent the body 33. The height at which the frames / arms are mounted on and project from the body 33 of the load handling apparatus 31 may be chosen to provide a desired effect. For example, it may be preferred for the frames / arms to project at a high level above the body 33 of the load handling apparatus 31 to allow a larger container (or multiple containers) to be lifted into the container receiving space below the frame / arms. Alternatively, the frame / arms may be positioned to protrude lower on the body 33 (but still high enough to accommodate at least one container between the frame / arms and the track system 13) to keep the center of gravity of the load handling apparatus 31 lower when the load handling apparatus 31 is loaded with containers.

[0040] To enable the load handling apparatus 31 to move on different wheels 35, 37 in the first and second directions, the load handling apparatus 31 includes a wheel positioning mechanism for selectively engaging either the first set of wheels 35 with the first set of tracks 17 or the second set of wheels 37 with the second set of tracks 19. The wheel positioning mechanism is configured to raise and lower the first set of wheels 35 and / or the second set of wheels 37 relative to the body 33, thereby enabling the load handling apparatus 31 to selectively move in either the first direction or the second direction across the tracks 17, 19 of the storage structure 1.

[0041] The wheel positioning mechanism may include one or more linear actuators, rotary components, or other means for raising and lowering at least one set of wheels 35, 37 relative to the body 33 of the load handling apparatus 31 to move the at least one set of wheels 35, 37 out of and into contact with the tracks 17, 19. In some examples, only one set of wheels is configured to be raised and lowered, such that the act of lowering one set of wheels may effectively lift the other set of wheels away from the corresponding tracks, while the act of raising one set of wheels may effectively lower the other set of wheels into contact with the corresponding tracks. In other examples, both sets of wheels may be raised and lowered, advantageously meaning that the body 33 of the load handling apparatus 31 remains at substantially the same height, thus eliminating the need for the weight of the body 33 and components mounted thereon to be lifted and lowered by the wheel positioning mechanism.

[0042] A plurality of load handling apparatus 31 are provided on top of the storage structure, where each load handling apparatus 31 may operate simultaneously (as described above) to increase the throughput of the system. Containers 9 may be transferred by the load handling apparatus 31 to one or more ports or exit / entry points (not shown) that transport containers 9 into and out of the storage structure. Similarly, containers 9 may be transferred by the load handling apparatus 31 from one or more ports / exit / entry points to stacks 11.

[0043] Communication between the gripping apparatus 100 and the body 33 of the load handling apparatus 31 as the gripping apparatus 100 is raised and / or lowered from the body 33 can be useful. For example, in some embodiments, the gripping apparatus 100 may communicate to the body 33 that it has reached a required position for lifting a container (i.e., reached a fully lowered position) before the gripping apparatus 100 is commanded to engage the container. In other embodiments, the gripping apparatus 100 may communicate to the body 33 that it has engaged or disengaged with a container before a tether can be wound to lift the gripping apparatus 100. In some embodiments, the gripping apparatus 100 may communicate to the body 33 the speed at which it is moving (i.e., the gripping apparatus 100 is being raised / lowered) and / or the position of the gripping apparatus 100 between the fully raised and fully lowered positions. This information is useful to enable the load handling apparatus 31 to control the speed at which the gripping apparatus 100 is moving. For example, the load handling apparatus 31 may be configured to reduce the speed of the gripping apparatus 100 as it approaches its fully lowered position to ensure that the gripping apparatus 100 is lowered accurately onto the container without damaging the gripping apparatus 100. The load handling apparatus 31 may be configured to reduce the speed of the gripping apparatus 100 as it approaches its fully raised position to ensure that the gripping apparatus 100 is raised accurately into the body 33 of the load handling apparatus 31 without damaging the gripping apparatus 100 or the body 33 of the load handling apparatus 31. In some embodiments, the load handling apparatus 31 may be configured to increase the speed of the gripping apparatus 100 as it moves between its fully lowered position and its fully raised position to increase efficiency.

[0044] Figure 6 shows a schematic front view of one embodiment of the load handling apparatus 31 with the gripping apparatus 100 shown in a lowered position. The tether connecting the gripping apparatus 100 to the body 33 is not included in Figure 6 for simplicity. The load handling apparatus 31 comprises a transmitter 112 and a receiver 114 that enable communication (i.e., data transmission) between the body 33 and the gripping apparatus 100. The transmitter 112 is coupled to the gripping apparatus 100 and configured to transmit data, and the receiver 114 is coupled to the body 33 and configured to receive data from the transmitter 112.

[0045] The transmitter 112 and the receiver 114 are configured to communicate via wireless communication, in particular via light-based communication. The transmitter 112 is an optical transmitter 112, such as a light emitting diode (LED), such as an infrared (IR) LED, configured to transmit an optical transmission, and the receiver 114 is an optical or photo detector configured to detect the optical transmission. Communication between the transmitter 112 and the detector depends on the light intensity and blinking of the transmitter 112.

[0046] The load handling apparatus 31 includes a controller 122, which in this embodiment is provided on the load handling apparatus 31 (i.e., in the body 33 of the load handling apparatus 31) and connectable to the receiver 114. The controller 122 is configured to control (i.e., provide instructions to) the operation of the body 33 and / or the gripping apparatus 100. The controller 122 is configured to interpret data received by the receiver 114 (from the transmitter 112) and determine information about the gripping apparatus 100 based on the data, including, for example, the position of the gripping apparatus 100 (e.g., between a fully raised and fully lowered position), whether the gripping apparatus 100 is engaged and / or disengaged from a container, the speed at which the gripping apparatus 100 is moving, etc. Based on the received information, the control device 122 is configured to provide commands to the main body 33 and / or the gripping device 100, including, for example, controlling the speed of the gripping device 100 as it moves, instructing the gripping device 100 to engage or disengage from a container, etc.

[0047] Figure 7 illustrates one embodiment of a load handling device 31 in which the receiver 114 includes a lens 116 for focusing the optical transmission (i.e., data) from the transmitter 112 onto the receiver 114. In the embodiment of Figures 6 and 7, the transmitter 112 comprises an omnidirectional optical transmitter 112 configured to transmit optical transmissions in multiple directions, i.e., 180 degrees in a circle around the transmitter 112. The lens 116 helps to ensure that the optical transmission is focused onto the receiver 114 so that the receiver 114 can pick up the data.

[0048] The load handling apparatus 31 of Figures 6 and 7 includes a power source (not shown) mounted to the body 33 and configured to power components within the body 33, including the receiver 114. The load handling apparatus 31 also includes a power source (not shown) on the gripper 100 and configured to power components of the gripper 100, including the transmitter 112. The gripper 100 is thus a self-powered gripper 100. However, in other embodiments, a power source may be provided only within the body 33 to power the components within the body 33, and a power cable may be provided connecting the power source within the body 33 to the gripper 100 to power the components of the gripper 100.

[0049] 1, the storage structure includes a plurality of cargo handling apparatus 31 that travel on top of the storage structure. At least some of the cargo handling apparatus 31 in the storage structure include a transmitter 112 and a receiver 114 as described above. In some embodiments, each of the cargo handling apparatus 31 in the storage structure includes a transmitter 112 and a receiver 114 as described above.

[0050] If multiple cargo handling apparatus 31, each including a transmitter 112 and a receiver 114, are provided, the risk of interference and crosstalk between the cargo handling apparatus 31 increases, for example, optical transmission (i.e., data) from the transmitter 112 of one cargo handling apparatus 31 may be received by the receiver 114 of another cargo handling apparatus 31.

[0051] To prevent interference and crosstalk between the various load handling equipment 31, each load handling equipment 31 is assigned a code generated using Code Division Multiple Access (CDMA). The code assigned to the load handling equipment 31 is recognizable between the transmitter 112 and receiver 114 of the load handling equipment 31. The transmitter 112 of the load handling equipment 31 transmits the code along with the data, and the receiver 114 discards any received data that does not have the code.

[0052] The code assigned to the load handling equipment 31 is a vector made up of ones and zeros (i.e., chips), and for each bit of data sent by the transmitter 112, the data is modulated by the code assigned to the load handling equipment 31. In this embodiment, the transmitter 112 transmits light during the one chip elements of the code and does not transmit light during the zero chip elements of the code. In turn, the receiver 114 of the same load handling equipment 31 generates its own copy of the code assigned to the load handling equipment 31 and multiplies the data received from the transmitter 112 by the vector code. If the value resulting from the multiplication is a large positive number, the receiver 114 correlates the data received by the transmitter 112 and sends this data to the controller 122 for processing. If the value resulting from the multiplication is a large negative number, the receiver 114 does not correlate the data received by the transmitter 112 and the receiver 114 discards the data. This ensures that the receiver 114 only correlates and recognizes data from transmitters 112 that belong to the same load handling equipment 31 and that are assigned the same code as the receiver 114. By ensuring that the receiver 114 only correlates data from transmitters 112 that belong to the same load handling equipment 31, this prevents crosstalk from other load handling equipment 31 (i.e., their transmitters 112) that are in the vicinity of a particular load handling equipment 31.

[0053] As mentioned above, to move a container from the top of the stack or to drop off a target container (e.g., onto the top of the stack or another location), the load handling apparatus 31 is configured to move on the track system 13 in the X and Y directions as necessary until it reaches a predetermined grid cell location such that the gripping apparatus 100 is positioned above the required location for moving or dropping off the container.

[0054] Each grid cell 15 in the storage structure is assigned a predefined code that is assigned to the load handling equipment 31 traveling on the track system 13. In particular, the code assigned to a predefined grid cell 15 is assigned to the load handling equipment 31 that stops or parks on the (predefined) grid cell 15 (e.g., the first grid cell 15) to pick up or drop off a target container. Thus, the code assigned to each load handling equipment 31 depends on the grid cell location of the load handling equipment 31, i.e., the grid cell 15 on which the load handling equipment 31 is located to pick up / drop off a target container. Once the load handling equipment 31 moves to a different grid cell location (e.g., the second grid cell 15), for example to pick up a container from a different stack or drop off a container to a different stack, the load handling equipment 31 is assigned the code assigned to the new grid cell location of the load handling equipment 31 (i.e., the second grid cell 15). Each time the load handling equipment 31 moves to a different grid cell location, the load handling equipment 31 is assigned a code that is assigned to the load handling equipment's 31 new grid cell location.

[0055] The load handling equipment 31 includes a communications interface configured to assign a code from an external communications manager. The code is assigned to the load handling equipment 31 once the load handling equipment 31 is stopped or parked at a predetermined grid cell location. However, in other embodiments, the code may be assigned before the load handling equipment 31 is stopped / parked at the predetermined grid cell location, for example, once the communications manager determines the predetermined grid cell location of the load handling equipment 31.

[0056] In some embodiments, each grid cell 15 in the storage structure is assigned a unique code. This may require a large number of unique codes to cover all grid cells 15 in the storage structure. For a given chip length, a limited number of unique codes may be generated. To increase the number of available unique codes, the chip length of the code may be increased, i.e., a 20 chip long vector code will generate a greater number of unique codes compared to a 10 chip long vector code.

[0057] In other embodiments, the code for each grid cell 15 is locally unique, that is, the code for a given grid cell 15 may be different from the codes in neighboring grid cells 15.

[0058] FIG. 8 shows a schematic top view of a grid storage structure with grid cells 15 and a schematic diagram of the codes assigned to the grid cells 15 of the storage structure. In this embodiment, the codes are repeated across the grid cells 15. For example, the code "3" is used for multiple grid cells 15. The codes are locally unique, i.e., the grid cells 15 adjacent (in both the X-direction and the Y-direction) to the grid cell 15 assigned with the code "3" are assigned different codes. In this embodiment, the two grid cells 15 adjacent (in the X-direction and the Y-direction) to the grid cell 15 assigned with the code "3" are assigned different codes, i.e., the same code is repeated every three grid cells 15. The codes assigned to each grid cell 15 are respectively assigned to the load handling equipment 31 parked in the grid cell 15. This prevents interference from transmitters 112 on load handling equipment 31 in adjacent grid cells 15, i.e., a receiver 114 on a load handling equipment 31 parked on a grid cell 15 assigned with code "3" will not recognize or correlate with data received from a transmitter 112 on a load handling equipment 31 parked in an adjacent grid cell 15. The signal from the transmitter 112 decreases as the distance from the transmitter 112 increases, such that beyond a maximum travel distance (i.e., the maximum crosstalk length of the transmitter 112), the signal from the transmitter 112 is no longer detectable or receivable by the receiver 114. This allows the code "3" to be reused and assigned to another grid cell 15 located beyond the maximum crosstalk length without causing interference. In this embodiment, the distance between two grid cells 15 assigned with the same code (e.g., code "3") is twice the maximum crosstalk length of the transmitter 112. However, in other embodiments, the distance between two grid cells 15 assigned the same code may be shorter (e.g., 1x the maximum crosstalk length) or longer (e.g., 3x, 4x, 5x, 6x, 8x, 10x, 20x, etc. the maximum crosstalk length).

[0059] In the embodiment of Figure 8, multiple codes are repeated across the grid cells 15. In particular, the codes assigned to the grid cells 15 are repeated in a pattern across the grid cells 15. As shown in Figure 8, a set of nine unique codes are assigned in a pattern to the nine grid cells 15 across the storage structure. Codes 1, 2, 3, 4, 5, 6, 7, 8, 9 are assigned to the nine grid cells 15 in a 3x3 block of grid cells 15 and are repeated in the same pattern across the grid cells 15 for every 3x3 block of grid cells 15.

[0060] Those skilled in the art will appreciate that in other embodiments, any set number of unique codes may be assigned to the grid cells 15 in a pattern.

[0061] In the schematic diagram of Figure 8, the codes are represented for simplicity by single digits (1, 2, 3, 4, 5, 6, 7, 8 and 9). However, each code includes, for example, a vector made up of chips, e.g., chip length vectors of 2, 3, 4, 5, 6, 8, 10, 20, 30, 40, 50, 60, 61, 63, etc. Below are examples of nine codes, each with a 63 chip length vector, that may be allocated to grid cells 15: Example Code 1: 11111101010110011011101101101001001110001011110010100011000010000 Example Code 2: 000100000100100100001001111011010011010110001011011110111011 Example Code 3: 01001001000110110111000111011010000001000101110010010110111111 Example Code 4: 110111000011110011110010101010010001100100100010010001111111101 Example Code 5: 101111111001001100100110010100010001000011111000110101110100111001010 Example Code 6: 011110001100110011001001110011001010101101101111100001100110100100 Example Code 7: 01011001101010011101010100101010011010100011111100111001001001 Example Code 8: 01101110100110000000001011000111011110101000110110011101110101 Example Code 9: 01100011010101000111011100111100001111101010000100110100111010

[0062] The above codes may be allocated in a repeating pattern across the grid cells 15 of the storage structure. In the above example codes, each code (i.e., chip) is a Gold code that is 63 bits long. Furthermore, each code is balanced, i.e., the sum magnitude of each code is not greater than 1. Those skilled in the art will appreciate that the above codes are only examples. Those skilled in the art will know numerous ways to generate suitable codes for grid cells 15 of any bit or chip length.

[0063] In some embodiments, the receiver 114 and transmitter 112 of the load handling equipment 31 need to be synchronized in order for the receiver 114 and transmitter 112 to communicate with each other and for the receiver 114 to receive and recognize (i.e., correlate) data from the transmitter 112. In particular, the receiver 114 is configured to generate an (assigned) code as the transmitter 112 sends its data. To enable this, the receiver 114 and the transmitter 112 each include a respective clock 118, 120 that can be synchronized with each other.

[0064] To maintain synchronicity between the receiver 114 and the transmitter 112, their clocks 118, 120 may need to be resynchronized with each other (e.g., within a predetermined time interval). In some cases, synchronicity between the receiver 114 and the transmitter 112 may be lost as the gripping apparatus 100 moves away from the body 33 (e.g., as the gripping apparatus 100 is lowered toward a target container). To maintain or restore synchronicity between these two parts, the receiver clock 118 and the transmitter clock 120 are configured to synchronize and resynchronize each time the gripping apparatus 100 is raised and recoupled to the body 33. Once the gripping apparatus 100 is recoupled to the body 33, the controller 122 is configured to synchronize the receiver clock 118 with the transmitter clock 120.

[0065] In some embodiments, the receiver 114 is configured to generate the (assigned) code multiple times as the transmitter 112 sends its data. If the receiver 114 generates the code asynchronously with the transmitter 112 that is sending its data, the receiver 114 and the transmitter 112 cannot correlate and the receiver 114 will not recognize the data from the transmitter 112. FIG. 9A shows the receiver 114 generating an example vector code "10011" multiple times as the transmitter 112 sends its data. As shown in FIG. 9A, the receiver 114 generates the code asynchronously with the code received from the transmitter 112, resulting in the receiver 114 and the transmitter 112 having no or low correlation and not locking with each other (i.e., the receiver 114 cannot recognize the code from the transmitter 112). The receiver 114 ignores the received data and does not forward it to the controller 122 for further processing. The receiver 114 continues to generate codes, and as it generates codes, it rotates the vector code starting at different points along the vector code. In particular, the receiver 114 generates vector codes that are transposed or shifted by one chip along the vector code. As shown in FIG. 9B, if the receiver 114 has the same code as the transmitter 112, the vector code generated by the receiver 114 will eventually synchronize or align with the code being transmitted by the transmitter 112, resulting in the receiver 114 and the transmitter 112 having a high correlation and locking to each other (i.e., the receiver 114 recognizes the code from the transmitter 112). The receiver 114 holds the received data and transmits it to the controller 122 for further processing.

[0066] By providing a load handling apparatus 31 in which the receiver 114 is configured to generate a code multiple times as the transmitter 112 transmits its data until the code from the receiver 114 is synchronized and aligned with the code transmitted by the transmitter 112, the receiver 114 can advantageously correlate and recognize the code from the transmitter 112 without having to synchronize the receiver clock with the transmitter clock. Thus, a load handling apparatus 31 employing the method shown in Figures 9A and 9B does not need to synchronize the receiver clock with the transmitter clock each time the gripper 100 is recoupled with the body 33.

[0067] All optional and preferred features and modifications of the described embodiments and the dependent claims can be used in all aspects of the invention taught herein. Furthermore, the individual features of the dependent claims, and all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with each other.

Claims

1. 1. A load handling apparatus for lifting and moving stacked containers in a grid storage structure having a track system, the load handling apparatus being configured to travel on the track system, the load handling apparatus comprising: a transmitter configured to transmit data; and a receiver configured to receive the data from the transmitter; The cargo handling equipment is assigned a code such that the transmitter is configured to transmit the code along with the data and the receiver is configured to discard received data that does not comprise the code.

2. 2. The cargo handling apparatus of claim 1, wherein the transmitters are configured to send their data modulated by the assigned code, and the receivers are configured to correlate the data received by the transmitters such that the receivers are configured to recognize only the data received from transmitters that are correlated with that transmitter's data.

3. 3. A load handling apparatus according to claim 1 or 2, wherein the transmitter is configured to transmit an optical transmission and the receiver is configured to receive an optical transmission.

4. A load handling equipment according to any preceding claim, wherein the load handling equipment is assigned a unique code.

5. 5. The load handling equipment of claim 1, wherein the track system is arranged in a grid pattern above the stack of containers, the track system comprising a plurality of grid cells, each grid cell being assigned a predetermined code.

6. 6. The load handling device of claim 5, wherein the load handling device is configured to travel on the rail system to a predetermined grid cell location, and the code allocated to the grid cell location is assigned to the load handling device.

7. The load handling equipment of any one of claims 1 to 6, wherein the load handling equipment comprises a communications interface configured to allocate the code from an external communications manager.

8. 8. The load handling equipment of claim 7, wherein the communications interface is configured to assign the code to the load handling equipment once the load handling equipment is stopped at the predetermined grid cell location.

9. 9. The load handling apparatus of claim 5, wherein the load handling apparatus is configured to move to a first predetermined grid cell location where the load handling apparatus is assigned the code allocated to the first predetermined grid cell location, and the load handling apparatus is configured to move to a second predetermined grid cell location where the load handling apparatus is assigned the code allocated to the second predetermined grid cell location.

10. A cargo handling device as claimed in any one of claims 1 to 9, wherein the receiver and the transmitter are configured to be synchronised with each other such that the receiver generates the code assigned to the cargo handling device at the same time that the transmitter sends its data.

11. Load handling equipment according to any preceding claim, wherein the receiver and the transmitter each comprise a respective clock, said clocks being capable of being synchronised with each other.

12. The load handling apparatus of any one of claims 1 to 11, comprising a vehicle body and a gripping device, wherein the receiver is coupled to the body and the transmitter is coupled to the gripping device, and the transmitter is configured to transmit information from the gripping device.

13. 13. The load handling apparatus of claim 12, wherein the gripping device is configured to be lowered away from the vehicle body and raised back onto the vehicle body, and the receiver clock and the transmitter clock are configured to be synchronized when the gripping device is returned to the vehicle body.

14. 14. The load handling apparatus of claim 12 or 13, further comprising a control device connectable to the receiver and configured to interpret the data received by the receiver, the control device being configured to provide commands to the gripping device based on the data received.

15. a grid storage structure for receiving containers stacked in a stack, said grid storage structure comprising a track system arranged in a grid pattern comprising a plurality of grid cells; A plurality of load handling apparatus according to any one of claims 1 to 14; A system comprising:

16. 16. The system of claim 15, wherein the system comprises a communications manager configured to define and manage the codes assigned to the load handling equipment.

17. 17. A system as claimed in claim 15 or 16, wherein each load handling equipment is assigned a unique code.

18. A system as claimed in any one of claims 15 to 17, wherein each grid cell is assigned a predetermined code which is assigned to the load handling equipment travelling on the rail system.

19. 20. The system of claim 18, wherein the load handling equipment is configured to travel on the rail system to a predetermined grid cell location, and the code allocated to the grid cell is assigned to the load handling equipment.

20. 20. A system as claimed in claim 18 or 19, wherein the code for each grid cell is unique, whereby each of the load handling equipment is assigned a unique code.

21. 20. The system of claim 18 or 19, wherein the code for each grid cell is locally unique.

22. 20. The system of claim 18 or 19, wherein at least one of the codes assigned to the grid cells is repeated across the grid cells.

23. 23. The system of claim 18, 19, 21 or 22, wherein the codes assigned to the grid cells repeat in a pattern across the grid cells.

24. 24. The system of claim 18, 19, 21, 22 or 23, wherein a set number of unique codes are distributed among the grid cells in a pattern, the pattern of codes being repeated across the grid cells.

25. A system according to any one of claims 19 to 24, wherein the code is assigned to the load handling equipment once the load handling equipment is parked at the predetermined grid cell location.

26. 26. A system as claimed in any one of claims 18 to 25, wherein each load handling equipment is configured to move to a first predetermined grid cell location where the load handling equipment is assigned the code allocated to the first predetermined grid cell location, and each load handling equipment is configured to move to a second predetermined grid cell location where the load handling equipment is assigned the code allocated to the second predetermined grid cell location.

27. A method for controlling a load handling apparatus, said method comprising a load handling apparatus according to any one of claims 1 to 14, The method comprises: A method comprising the step of assigning a code to the load handling equipment.

28. A method for controlling a system, said method comprising a system according to any one of claims 15 to 26, said method comprising the steps of: assigning a code to each grid cell; assigning said codes to said load handling devices traveling on said rail system; A method comprising:

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