Method and system for determining the depth or obstruction of a gripping assembly

Abstract

A method and system for determining the depth or obstruction of a container gripping assembly is disclosed.The method and system uses a sensor to determine the depth or obstruction of a container gripping assembly.

Description

Technical Field

[0001] The present invention relates to a method and system for determining the depth of a gripping assembly such as used in a load handling device.

Background Art

[0002] Several commercial and industrial activities require systems that enable the storage and retrieval of a number of different products. WO2015 / 185628A describes a storage and fulfillment system in which stacks of storage containers are arranged within a grid framework structure. The containers are accessed from above by a load handling device operating on rails or tracks located at the top of the grid storage structure. The load handling device is further described in WO2015 / 019055A1.

[0003] The load handling device comprises a container lifting assembly that uses a lifting and lowering assembly to raise and / or lower a container gripping assembly. The lifting and lowering assembly controls the raising and lowering of the container gripping assembly in accordance with the vertical position of the container gripping assembly. For example, when the container gripping assembly is lowered and approaches the container, the container gripping assembly decelerates. In order to control the deceleration, it is important to accurately determine the vertical position of the container gripping assembly. The same applies when the container gripping assembly rises and approaches the load handling device. It is also important to determine whether the container gripping assembly has been obstructed during its raising and lowering. The present invention has been devised in view of such a background.

Summary of the Invention

[0004] In a first aspect, there is a lifting assembly for raising a container from a stack of containers within a grid storage structure and / or lowering a container onto a stack of containers, the lifting assembly comprising a gripping assembly configured to grip a load, The assembly comprises a lifting assembly configured to raise and lower a gripping assembly, and the lifting assembly is At least one tether connected to the gripping assembly, A motor for winding up and / or unwinding the tethers to raise and / or lower the gripping assembly, wherein the lifting assembly further comprises: A sensor configured to detect the movement of a gripping assembly, wherein the sensor is The gripping assembly has an input that is engaged by movement, The system includes a controller configured to determine the vertical position of the gripping assembly using the output of a sensor. This means that the extent to which the gripping assembly has risen and / or descended can be monitored.

[0005] The lifting assembly may include an electrical cable connected to a gripping assembly, wherein the electrical cable is configured to retract and / or unwind as the gripping assembly is raised and / or lowered, and a sensor is configured to detect the extent to which the electrical cable is retracted and / or unwinded. This means that the vertical position can be precisely determined using a direct extension of the electrical cable. In one implementation, the lifting assembly further includes an electrical cable spool from which the electrical cable is retracted and / or unwinded, wherein a sensor includes a rotary encoder configured to engage with the electrical cable spool to detect the extent to which the electrical cable spool has rotated as the electrical cable is retracted and / or unwinded.

[0006] Electrical cables may have a higher modulus of elasticity than the aforementioned or each tether. This means that the effects of stretching are reduced and accuracy is maximized.

[0007] The lifting assembly may further comprise a tether spool for the or each tether from which the or each tether is wound and / or unwound, wherein the electrical cable spool and the or each tether spool are mounted on a shaft so that the electrical cable spool rotates relative to the or each tether spool. In one implementation, the lifting assembly of the claim further comprises a biasing assembly configured to resist the unwinding or winding of the electrical cable spool so that the electrical cable is tensioned between the lifting assembly and the gripping assembly. This means that the electrical cable remains taut and accuracy is maximized.

[0008] The electrical cable can communicate electrical signals to the gripping assembly. The electrical cable may include a flat fixed flexible cable, an FFC, or a ribbon cable.

[0009] The sensor may include a motor encoder for the motor, wherein the motor encoder is configured to detect the degree to which the or each tether is wound up and / or unwound. This means that the vertical position can be precisely determined using the direct extension of the or each tether. In one implementation, the lifting assembly may further include a tether spool for the or each tether from which the or each tether is wound up and / or unwound, wherein the motor encoder detects the degree to which the or each tether spool has rotated as the or each tether is wound up and / or unwound. The sensor may include a rotary encoder configured to detect the degree to which the or each tether is wound up and / or unwound, or a rotary encoder for the or each tether, wherein the or each rotary encoder is configured to engage with the or each spool to detect the degree to which the or each spool has rotated as the or each tether is wound up and / or unwound.

[0010] The sensor may include a rotary encoder for the aforementioned or each tether, wherein the rotary encoder is configured to contact each tether such that the winding and / or unwinding of the aforementioned or each respective tether rotates the input of the rotary encoder. This means that the direct extension of the tether can be used to precisely determine the vertical position.

[0011] The lifting assembly may include an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to retract and / or unwind when the gripping mechanism is raised and / or lowered, and the sensor may include a rotary encoder, wherein the rotary encoder is configured to engage with the electrical cable such that the retraction and / or unwinding of the tether or each tether rotates the shaft of the rotary encoder. This means that the vertical position can be precisely determined using a direct extension of the electrical cable.

[0012] The lifting assembly may further comprise a biasing assembly configured to bias the rotary encoder or each rotary encoder into contact with the tether or each respective electrical cable. This ensures that the rotary encoder maintains contact with each respective tether or electrical cable.

[0013] The lifting assembly may include a wire connected to a gripping device, wherein the wire is configured to be wound up and / or unwound as the gripping assembly rises and / or falls, and a wire spool from which the wire is wound up and / or unwound, wherein the wire is wound onto the wire spool such that the wire on the wire spool is short-circuited, wherein a sensor may be configured to measure the electrical resistance of the wire as the wire is wound up and / or unwound. This means that the vertical position can be precisely determined using a direct extension of the wire.

[0014] The lifting assembly may further include a biasing assembly configured to resist the unwinding or winding of the wire spool so that the wire is tensioned between the lifting assembly and the gripping assembly. This means that the wire remains taut and accuracy is maximized.

[0015] The sensor may include a time-of-flight (TF) sensor. This means that the vertical position can be precisely determined using the direct movement of the gripping assembly.

[0016] The sensor may comprise a light source and a photodetector, wherein the light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly is raised and / or lowered, and the photodetector may be configured to detect a reflection of the optical signal from the surface to detect the movement of the surface. This means that the vertical position can be precisely determined using the direct movement of the gripping assembly. In one implementation, the lifting assembly may comprise an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to be wound up and / or unwound as the gripping mechanism is raised and / or lowered. The lifting assembly may comprise a wheel that contacts a tether spool or an electrical cable spool from which the tether or each of the tethers is wound and / or unwound, wherein the wheel comprises a surface. The tether spool or each of the tethers, or the electrical cable spool, may comprise a surface.

[0017] The controller may be configured to use a determined vertical position to control / adjust the raising and / or lowering of the gripping assembly. This means that the gripping assembly can be precisely controlled using feedback.

[0018] In another embodiment, there is a cargo handling device for lifting and moving storage containers stacked within a grid framework structure, To form a grid pattern comprising multiple grid spaces, the system comprises a first set of parallel rails or tracks and a second set of parallel rails or tracks extending substantially perpendicular to the first set of rails or tracks in a substantially horizontal plane, wherein the grid is supported by a set of upright members to form multiple vertical storage positions directly beneath the grid, such that containers are stacked vertically between the upright members and guided by the upright members, and the cargo handling device is A body or frame attached to a first set of wheels arranged to engage with a first set of parallel tracks, and a second set of wheels arranged to engage with a second set of parallel tracks, A container lifting assembly comprising a lifting assembly of any prior embodiment, wherein the gripping assembly comprises a container gripping assembly configured to grip a container.

[0019] In another embodiment, there is a method for determining the vertical position of a gripping assembly of any prior embodiment, wherein the method is Using a motor to raise and / or lower the gripping assembly, The system includes using a controller to determine the vertical position of the gripping assembly using the output of a sensor.

[0020] In another embodiment, there is a computer program comprising instructions, and when the program is executed by a computer, the computer is made to perform the method of the previous embodiment.

[0021] In one embodiment, there is a lifting assembly for raising a container from a stack of containers in a grid storage structure and / or lowering a container into a stack of containers, and the lifting assembly is A gripping assembly configured to grip a load, The assembly comprises a lifting assembly configured to raise and lower a gripping assembly, and the lifting assembly is At least one tether connected to the gripping assembly, A motor configured to wind and / or unwind the or each tether around at least one shaft to raise and / or lower the gripping assembly, wherein the lifting assembly further comprises A sensor configured to detect the movement of the gripping assembly, A controller configured to determine a malfunction of the gripping assembly if the current output of the sensor does not correlate with the winding and / or unwinding of the or each tether around the or each shaft for raising and / or lowering the gripping assembly. This means that malfunctions or inaccurate movements during the raising and / or lowering of the gripping assembly can be detected.

[0022] The lifting assembly of claim 1 further comprises a second sensor, wherein the second sensor directly detects the rotation of at least one shaft. This means that the winding and / or unwinding of the or each tether can be detected.

[0023] In one implementation, the second sensor may comprise a motor encoder of the motor, wherein the controller may be configured to determine a malfunction of the gripping assembly if the current output of the sensor does not correlate with the current output of the motor encoder. The controller may be configured to determine a malfunction of the grid assembly if the current output of the sensor does not correlate with the current output of the motor encoder by a threshold. This means that a tolerance is allowed to account for the elongation of the or each tether.

[0024] In another implementation, the lifting assembly may further comprise a tether spool for the tether or each tether from which the tether or each tether is wound and / or unwound, wherein the second sensor may comprise a tether rotary encoder for the tether or each tether spool, wherein the tether rotary encoder may be configured to engage with the tether or each spool to detect the degree to which the tether or each spool has rotated when the tether or each tether is wound and / or unwound, wherein the controller is configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the tether rotary encoder by a threshold. The controller may be configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the tether rotary encoder by a threshold. This means that tolerances are allowed to account for the stretching of the tether or each tether.

[0025] In another implementation, the lifting assembly may include an electrical cable connected to a gripping assembly, wherein the electrical cable is configured to wind up and / or unwind as the gripping assembly is raised and / or lowered, and an electrical cable spool from which the electrical cable winds up and / or unwinds, wherein the electrical cable spool is fixedly mounted to the or each shaft, wherein the second sensor includes an electrical cable rotary encoder for the electrical cable spool, wherein the or each electrical cable rotary encoder is configured to engage with the electrical cable spool to detect the degree to which the electrical cable spool has rotated as the electrical cable winds up and / or unwinds, wherein the controller is configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the electrical cable rotary encoder.

[0026] In another implementation, the lifting assembly may further comprise a tether spool for the said or each tether from which the tether is wound and / or unwound, wherein the second sensor comprises a tether spool sensor comprising a light source and a photodetector, wherein the light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly rises and / or descends, wherein the photodetector is configured to detect a reflection of the optical signal from the surface to detect the movement of the surface, wherein the controller is configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the tether spool sensor. The lifting assembly may further comprise wheels that contact the tether spool from which the said or each tether is wound and / or unwound, wherein the wheels comprise a surface. The said or each tether spool may comprise a surface.

[0027] In another implementation, the lifting assembly may include an electrical cable connected to a gripping assembly, wherein the electrical cable is configured to wind up and / or unwind when the gripping assembly is raised and / or lowered, and an electrical cable spool from which the electrical cable winds up and / or unwinds, wherein a second sensor includes an electrical cable spool sensor comprising a light source and a photodetector, wherein the light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly is raised and / or lowered, and the photodetector is configured to detect a reflection of the optical signal from the surface to detect the movement of the surface, wherein a controller is configured to determine a fault in the gripping assembly if the current output of the sensor does not correlate with the current output of the electrical cable spool sensor. The lifting assembly may also include a wheel that contacts the electrical cable spool from which the electrical cable winds up and / or unwinds, wherein the wheel has a surface. The electrical cable spool may have a surface.

[0028] The sensor may have an input that is engaged by the movement of the gripping assembly, wherein the controller may receive a motion profile that controls the upward and / or downward movement of the gripper assembly, use the sensor's output to determine the vertical position of the gripping assembly, and determine a fault of the gripping assembly if the vertical position of the gripping assembly at the current time does not correlate with the corresponding vertical position derived from the motion profile by a threshold. This means that a fault can be determined using a single sensor.

[0029] The lifting assembly may include an electrical cable connected to a gripping assembly, wherein the electrical cable may be configured to be retracted and / or untracted as the gripping assembly is raised and / or lowered, wherein a sensor may be configured to detect the degree to which the electrical cable is retracted and / or untracted, and the biasing assembly is configured to resist the untracting or retraction of the electrical cable spool so that the electrical cable is taut between the lifting assembly and the gripping assembly. The lifting assembly may further include an electrical cable spool from which the electrical cable is retracted and / or untracted, wherein a sensor may include a rotary encoder configured to engage with the electrical cable spool to detect the degree to which the electrical cable spool has rotated as the electrical cable is retracted and / or untracted, wherein the electrical cable spool may be configured to rotate relative to the said or each shaft. This means that the electrical cable returns to its biased state when the movement of the gripping assembly is obstructed, which is detected by the rotary encoder. In one implementation, the electrical cable may have a higher modulus of elasticity than the aforementioned or each tether. In another implementation, the electrical cable may communicate electrical signals to the gripping assembly. In yet another implementation, the electrical cable may comprise a flat flexible cable, an FFC, or a ribbon cable.

[0030] The sensor may include a rotary encoder for the or each tether, wherein the rotary encoder is configured to contact each tether such that the winding and / or unwinding of the or each tether rotates the input of the rotary encoder. The lifting assembly may include an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to wind and / or unwind when the gripping mechanism is raised and / or lowered, wherein the electrical cable is optionally a flat flexible cable, FFC, or ribbon cable, wherein the sensor may include a rotary encoder, wherein the rotary encoder is configured to engage with the electrical cable such that the winding and / or unwinding of the or each tether rotates the shaft of the rotary encoder. This means that loss of contact between the rotary encoder and the or each tether or electrical cable, for example due to loosening, is detected by the rotary encoder. The biasing assembly may be configured to bias the or each rotary encoder to contact the or each tether or electrical cable. This ensures reliable contact between the rotary encoder and the aforementioned or each of the tethers or electrical cables.

[0031] The lifting assembly comprises an electrical cable connected to a gripping assembly, wherein the electrical cable is configured to wind up and / or unwind when the gripping mechanism is raised and / or lowered, and an electrical cable spool from which the electrical cable winds up and / or unwinds, wherein the electrical cable spool is configured to rotate with respect to the or each shaft and is configured to resist the unwinding or winding of the electrical cable spool so that the electrical cable is taut between the lifting assembly and the gripping assembly, wherein the sensor comprises an electrical cable spool sensor comprising a light source and a photodetector, wherein the light source is configured to transmit an optical signal to a surface that moves when the gripping assembly is raised and / or lowered, and the photodetector is configured to detect a reflection of the optical signal from the surface to detect the movement of the surface, wherein the lifting assembly may comprise wheels in contact with the or each respective tether winding up and / or unwinding electrical cable spool, wherein the wheels comprise a surface, or wherein the electrical cable spool comprises a surface. This means that the electrical cable will return to its biased state when the movement of the gripping assembly is obstructed, and this is detected by the electrical cable spool sensor.

[0032] The lifting assembly may include a wire connected to a gripping device, wherein the wire is configured to be wound up and / or unwound as the gripping assembly is raised and / or lowered, a wire spool from which the wire is wound and / or unwound, wherein the wire is wound onto the wire spool such that the wire on the wire spool is short-circuited, and wherein the wire spool is configured to rotate relative to the shafts, and a biasing assembly configured to resist the unwinding or winding of the wire spool so that the wire is taut between the lifting assembly and the gripping assembly, wherein a sensor is configured to measure the electrical resistance of the wire when the wire is wound up and / or unwound. This means that if the movement of the gripping assembly is obstructed, the wire returns to its biased state, which is detected by the sensor.

[0033] The sensor may include a time-of-flight (TF) sensor that detects when the movement of the gripping assembly is being obstructed.

[0034] The controller may be configured to stop the motor when it detects a failure in the gripping assembly. This means that the otherwise loose tether will not unwind.

[0035] In another embodiment, there is a cargo handling device for lifting and moving storage containers stacked within a grid framework structure, To form a grid pattern comprising multiple grid spaces, the system comprises a first set of parallel rails or tracks and a second set of parallel rails or tracks extending substantially perpendicular to the first set of rails or tracks in a substantially horizontal plane, wherein the grid is supported by a set of upright members to form multiple vertical storage positions directly beneath the grid, such that containers are stacked vertically between the upright members and guided by the upright members, and the cargo handling device is A body or frame attached to a first set of wheels arranged to engage with a first set of parallel tracks, and a second set of wheels arranged to engage with a second set of parallel tracks, A container lifting assembly comprising a lifting assembly of any prior embodiment, wherein the gripping assembly comprises a container gripping assembly configured to grip a container in a releaseable manner.

[0036] In another embodiment, there is a method for determining an obstruction of a lifting assembly of any prior embodiment to a gripping assembly, wherein the method is: Using a motor to raise and / or lower the gripping assembly, The system includes using a controller to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the winding and / or unwinding of the tethers around the shafts or each shaft for raising and / or lowering the gripping assembly.

[0037] In another embodiment, there is a computer program comprising instructions, and when the program is executed by a computer, the computer is made to perform the method of the preceding embodiment. [Brief explanation of the drawing]

[0038] The present invention will be described with reference to one or more exemplary embodiments as depicted in the accompanying drawings. [Figure 1] Figure 1 shows the storage structure and containers. [Figure 2] Figure 2 shows the track located on top of the storage structure illustrated in Figure 1. [Figure 3] Figure 3 shows the cargo handling device located above the storage structure illustrated in Figure 1. [Figure 4] Figure 4 shows a single cargo handling device in which the container lifting mechanism is in a downward configuration. [Figure 5A]Figure 5A shows a cutaway view of a single cargo handling device in which the container lifting means is in an upward configuration. [Figure 5B] Figure 5B shows a cutaway view of a single cargo handling device in which the container lifting mechanism is in a downward configuration. [Figure 6] [Figure 7] Figure 7 shows the method according to the present invention. [Figure 8] Figure 8 shows the system according to the present invention. [Figure 9] Figure 9 shows the system according to the present invention. [Figure 10] Figure 10 shows a system according to the present invention. [Figure 11A] Figure 11A shows a sensor according to the present invention. [Figure 11B] Figure 11B shows a sensor according to the present invention. [Figure 12] Figure 12 shows another sensor according to the present invention. [Figure 13] Figure 13 shows another sensor according to the present invention. [Figure 14] Figure 14 shows another sensor according to the present invention. [Figure 15] Figure 15 shows another sensor according to the present invention. [Figure 16] Figure 16 shows a system according to the present invention. [Figure 17] Figure 17 shows the method according to the present invention. [Modes for carrying out the invention]

[0039] Online retail businesses that sell multiple product lines, such as online grocery stores and supermarkets, require systems capable of storing tens or even hundreds of thousands of different product lines. Using single-product stacks in such cases is impractical because it requires a very large floor area to accommodate all the necessary stacks. Furthermore, single-product stacks are an inefficient solution when it's desirable to store small quantities of certain items, such as perishable goods or items that aren't ordered very often.

[0040] International patent application WO98 / 049075A (Autostore), the contents of which are incorporated herein by reference, describes a system in which multiple product stacks of containers are arranged within a frame structure.

[0041] PCT Publication No. WO2015 / 185628A (Ocado) describes further known storage and fulfillment systems in which stacks of containers are located within a grid framework structure (or grid storage structure). Containers are accessed by one or more load handling devices, also known as "bots," which are operable on trucks located at the top of the grid framework structure. This type of system is schematically illustrated in Figures 1-3 of the attached drawings.

[0042] As shown in Figures 1 and 2, stackable containers 10, also known as "bins," are stacked on top of each other to form a stack 12. The stack 12 is located within a grid framework structure 14 in a warehouse storage environment or manufacturing environment. The grid framework 14 consists of multiple storage columns or grid columns. Each grid within the grid framework structure has at least one grid column for storing the stack of containers. Figure 1 is a schematic perspective view of the grid framework structure 14, and Figure 2 is a schematic top view showing the stack 12 of bins 10 located within the framework structure 14. Each bin 10 typically holds multiple product items (not shown). The product items in the bin 10 may be of the same product type or different product types, depending on the application.

[0043] The grid framework structure 14 comprises a plurality of upright members 16 supporting horizontal members 18, 20. A first set of parallel horizontal members 18 is arranged perpendicular to a second set of parallel horizontal members 20 in a grid pattern, so as to form a horizontal grid structure 15 supported by the upright members 16. Members 16, 18, 20 are typically manufactured from metal. The bins 10 are stacked between members 16, 18, 20 of the grid framework structure 14 so as to guard against the horizontal movement of the stack 12 of bins 10 and guide the vertical movement of the bins 10.

[0044] The top level of the grid framework structure 14 comprises a grid or grid structure 15, which includes rails 22 arranged in a grid pattern across the top of the stack 12. Referring to Figure 3, the rails or tracks 22 guide a plurality of load handling devices 30. A first set 22a of parallel rails 22 guides the movement of the robot load handling devices 30 in a first direction (e.g., the X direction) across the top of the grid framework structure 14. A second set 22b of parallel rails 22, positioned perpendicular to the first set 22a, guides the movement of the load handling devices 30 in a second direction (e.g., the Y direction) perpendicular to the first direction. In this way, the rails 22 allow the robot load handling devices 30 to move laterally in two dimensions within the horizontal XY plane. The load handling devices 30 can be moved to any position above the stack 12.

[0045] As shown in Figures 4, 5A and 5B, known forms of cargo handling devices 30 are described in PCT Patent Publication WO2015 / 019055 (Ocado), which is incorporated herein by reference, and each cargo handling device 30 covers a single grid space of the grid framework structure 14. This configuration allows for a higher density of cargo handlers and therefore a higher throughput for a given size system.

[0046] The cargo handling device 30 comprises a vehicle 32 positioned to move on rails 22 of a frame structure 14. A first set of wheels 34, consisting of a pair of wheels 34 at the front of the vehicle 32 and a pair of wheels 34 at the rear of the vehicle 32, is positioned to engage with two adjacent rails of the first set 22a of rails 22. Similarly, a second set of wheels 36, consisting of a pair of wheels 36 on each side of the vehicle 32, is positioned to engage with two adjacent rails of the second set 22b of rails 22. Since each set of wheels 34 and 36 can be raised and lowered via a reversal assembly, either the first set of wheels 34 or the second set of wheels 36 is always engaged with the respective sets of rails 22a and 22b. For example, when a first set of wheels 34 is engaged with a first set of rails 22a and a second set of wheels 36 is fully lifted off the rails 22, the first set of wheels 34 can be driven via a drive assembly housed in the vehicle 32 to move the load handling device 30 in the X direction. To achieve movement in the Y direction, the first set of wheels 34 is lifted away from the rails 22, and the second set of wheels 36 is lowered and engaged with a second set 22b of the rails 22. The drive assembly can then be used to drive the second set of wheels 36 to move the load handling device 30 in the Y direction.

[0047] The cargo handling device 30 is equipped with a container lifting device, such as a crane mechanism, for lifting storage containers from above. The container lifting assembly comprises a lifting assembly (an example of which is shown in Figure 9) having a winch tether or cable 38 wound on a spool or reel, and a container gripping assembly 39. The lifting assembly also comprises a motor for rotating the spool and thus winding and / or unwinding the tether. The lifting assembly shown in Figure 4 comprises a set of four vertically extending lifting tethers 38. The tethers 38 are connected to, or near, each of the four corners of the container gripping assembly 39, for example, the lifting frame, for a releasable connection to the storage container 10. For example, each tether 38 is located at, or near, each of the four corners of the container gripping assembly 39. The container gripping assembly 39 is configured to releasably grip the top of the storage container 10 in order to lift the storage container 10 from a stack of containers in the type of storage system shown in Figures 1 and 2. For example, the container gripping assembly 39 may include a pin (not shown) that engages with a corresponding hole (not shown) in a rim forming the uppermost surface of the bin 10, and a slide clip (not shown) that can engage with the rim to grip the bin 10. The clip is driven to engage with the bin 10 by a suitable drive mechanism housed within the container gripping assembly 39, which is powered and controlled by signals carried through the cable 38 itself or a separate control cable (not shown).

[0048] To retrieve the bin 10 from the top of the stack 12, the cargo handling device 30 is first moved in the X and Y directions so that it is positioned on the container gripping assembly 39 above the stack 12. The container gripping assembly is then lowered vertically in the Z direction by raising and / or lowering the assembly so that it engages with the bin 10 on top of the stack 12, as shown in Figures 4 and 5B. The container gripping assembly 39 grips the bin 10 and is then pulled upward by the cable 38 with the bin 10 attached. At the top of its vertical movement, the bin 10 is held above the rail 22 housed within the vehicle body 32. In this manner, the cargo handling device 30 can be moved to different positions in the XY plane to transport the bin 10 to a different location, carrying the bin 10 together with the cargo handling device 30. Upon reaching a target location (e.g., another stack 12, an access point in the storage system, or a conveyor belt), the bin or container 10 can be lowered from the container housing and released from the container gripping assembly 39. The cable 38 is long enough to allow the loading handling device 30 to take and place the bin from any level of the stack 12, including floor level.

[0049] As shown in Figure 3, multiple identical loading / unloading devices 30 are provided, and each loading / unloading device 30 can operate simultaneously to increase the system throughput. The system illustrated in Figure 3 may include specific locations known as ports, where bins 10 can be transported to or from the system. Each port is associated with an additional conveyor system (not shown), so that bins 10 transported to a port by a loading / unloading device 30 can be transported by the conveyor system to another location, for example, a picking station (not shown). Similarly, bins 10 can be moved from an external location, for example, a binning station (not shown), by the conveyor system to a port 24, and then transported by a loading / unloading device 30 to a stack 12 to replenish the stock in the system.

[0050] Each loading handling device 30 can lift and move one bin 10 at a time. The loading handling device 30 has a cavity or recess 40 at its bottom that receives a container. The recess 40 is sized to accommodate a container 10 when lifted by the lifting mechanism, as shown in Figures 5A and 5B. When in the recess, the container 10 is lifted away from the rail 22 below, and as a result, the vehicle 32 can move laterally to different grid locations. If it is necessary to retrieve a bin 10b ("target bin") that is not located at the top of the stack 12, the bins 10a ("non-target bins") above it must first be moved to allow access to the target bin 10b. This is achieved in an operation referred to below as "digging". Referring to Figure 3, during the digging operation, one of the loading handling devices 30 sequentially lifts each non-target bin 10a from the stack 12 containing the target bin 10b and places them in an empty position in another stack 12. The target bin 10b can then be accessed by the cargo handling device 30 and moved to the port for further transport.

[0051] Each of the provided cargo handling devices 30 can be operated remotely under the control of a central computer. Each individual bin 10 in the system is also tracked, and the appropriate bin 10 can be retrieved, transported, and replaced as needed. For example, the location of each non-target bin is logged so that non-target bins 10a can be tracked during digging operations.

[0052] Wireless communication and networks can be used to provide a communication infrastructure from a central computer to one or more cargo handling devices operating on a grid structure, for example, via one or more base stations. In response to receiving commands from the central computer, controllers within the cargo handling devices are configured to control the movement of the cargo handling devices by controlling various drive mechanisms. For example, a cargo handling device may be commanded to retrieve a container from a target storage column at a specific location on the grid structure. This command may include various movements in the XY plane of the grid structure 15. As described above, upon reaching the target storage column, the container lifting assembly can be operated to grip and lift the storage container 10 using the lifting assembly and the container gripping assembly 39. Once the container 10 is housed in the container receiving space 40 of the cargo handling device 30, the container 10 is then transported to another location on the grid structure 15, for example, a "drop-off port". At the drop-off port, the container 10 is lowered to a suitable picking station to allow the retrieval of any items within the storage container. The movement of the cargo handling device 30 on the grid structure 15 may also involve the cargo handling device 30 being instructed to move to a charging station located around the grid structure 15.

[0053] To operate the cargo handling devices 30 on the grid structure 15, each of the cargo handling devices 30 is equipped with a motor for driving wheels 34, 36. The wheels 34, 36 may be driven via one or more belts connected to the wheels, or they may be driven individually by motors incorporated into the wheels. In the case of a single-cell cargo handling device (where the installation area of ​​the cargo handling device 30 occupies a single grid cell 17), the motors for driving the wheels can be integrated into the wheels because the available space within the vehicle body is limited. For example, the wheels of a single-cell cargo handling device are driven by their respective hub motors. Each hub motor is equipped with an outer rotor having multiple permanent magnets arranged to rotate around a wheel hub, which has coils forming an inner stator.

[0054] The system described with reference to Figures 1 to 5 has many advantages and is suitable for a wide range of storage and retrieval operations. In particular, it allows for very dense storage of products and provides a very economical way to store a large range of different items in bin 10, while also allowing rational and economical access to all of bin 10 when needed for picking.

[0055] During storage and retrieval operations, the container lifting assembly uses the lifting assembly (examples of which are shown in Figures 4, 5A, 5B, 8, and 9) to raise and / or lower the container gripping assembly in the Z direction. The degree to which the container gripping assembly is raised or lowered varies across the grid storage structure 14. Each stack of containers in the grid storage structure 14 has a current dimension / height in the Z direction defined by the number of containers currently in that stack. The current dimension / height in the Z direction can be determined, for example, by tracking the containers raised from and / or lowered into each container's stack via a central computer. For example, if a stack currently has 10 containers and the containers have a fixed dimension / height in the Z direction, the current dimension / height of the stack in the Z direction can be determined to be 10 times the fixed dimension / height of the containers in the Z direction. It will be understood that the current dimensions / height of the stack in the Z direction can be expressed in an absolute sense, for example, n meters from the ground, or in a relative position, for example, n meters from the bottom of the grid storage structure 14, or n meters from the top of the grid storage structure.

[0056] The current dimensions / height in the Z direction of the stack of containers on which a cargo handling device is located can be communicated to the cargo handling device. The lifting assembly of the cargo handling device can use the current dimensions / height in the Z direction of the stack of containers to control the lifting and lowering of the container gripping assembly through operations to retrieve containers from or replace containers in the grid storage structure. In order to control the raising and / or lowering of the container gripping assembly in this way, the Z position (or vertical position, or position in a direction perpendicular to the plane on which the bot moves across the grid storage structure (i.e., defined by the X and Y directions)) of the container gripping assembly should be known. It will be understood that the Z position can be, for example, an absolute position n meters from the ground, or a relative position, for example, n meters from a container receiving cavity or recess 40, or n meters from the top of the grid storage structure, or n meters from the top of the upper container in the stack of containers on which the cargo handling device is located. The Z position allows for the determination of how close the container gripping assembly is to the top of the cargo handling device and / or the top of the uppermost container in the stack of containers. In this way, the container gripping assembly can be appropriately controlled, such as accelerating after being lowered from the cargo handling device and decelerating as it approaches the top of the uppermost container in the container stack. Similarly, the container gripping assembly can accelerate after being lifted from the top of the uppermost container in the container stack and decelerate as it approaches the cargo handling device.

[0057] During the raising or lowering of a container gripping assembly, the container gripping assembly may be obstructed. For example, the container gripping assembly may encounter defects in the grid storage structure 14, preventing the container gripping assembly from raising or lowering smoothly. One such exemplary defect may be a vertical member 16 having a projection that contacts the container gripping assembly. Another exemplary defect is when the container lifting assembly fails to recognize that it has contacted the top container in the stack and continues to unwind the tether. Excessive tether can be unwound onto an adjacent stack, potentially causing a blockage within that stack. Yet another defect is when, as one side of the container gripping assembly is raised or lowered to the extent that it contacts the vertical member 16 from which the container gripping assembly subsequently pivots, the container gripping assembly is no longer parallel to the XY plane and is potentially vertical. In any of these cases, the container gripping assembly is therefore prevented from operating correctly.

[0058] Therefore, it is advantageous to accurately determine the Z position of the container gripping assembly throughout the entire raising and / or lowering of the container gripping assembly. It is also advantageous to determine whether the container gripping assembly was obstructed during its raising and lowering, and, for example, whether the tether 38 was loose. Although the Z position and obstruction have been described in the context of cargo handling devices, it should be understood that it is also useful to determine the Z position and obstruction of the gripping assembly in any lifting device, such as a crane (i.e., a lifting device), which has a motor and tether (i.e., a lifting assembly) and a hook (i.e., a gripping assembly) that grips and raises and / or lowers the load.

[0059] Figure 6 shows a schematic diagram 600 of a cargo handling device 30 according to the present invention. The dashed lines show the body 32 of the cargo handling device moving on the grid 22 via wheels 34 / 36. A lifting assembly 610 (as shown in Figures 4, 5A, 5B, 8, and 9), driven by a motor (not shown), raises and lowers the container gripping assembly 39 by winding and unwinding a tether 38. One or more sensors 640 are configured to detect the movement of the container gripping assembly. The cargo handling device 600 can use a processor or controller 650 to receive and transmit data from and to the lifting assembly 610 and the one or more sensors 640, respectively. This data may be stored in a storage device 660. The data in the storage device 660 may be periodically transmitted for further processing via one or more networks, such as base stations.

[0060] Figure 7 shows steps of Method 700 for use in a lifting assembly (such as those used in a cargo handling device or crane), comprising a gripping assembly configured to grip a load, a lifting assembly configured to raise and lower the gripping assembly, the lifting assembly comprising at least one tether connected to the gripping assembly, and a motor for winding up and / or unwinding the tether to raise and / or lower the gripping assembly. It should be understood that the Method of Figure 7 can be performed using a controller (e.g., controller 650 of the cargo handling device in Figure 6). In step 710, the motor of the lifting assembly is used to raise and / or lower the gripping assembly, for example, as shown in Figure 8 or Figure 9. In step 720, a sensor is used to detect the movement of the gripping assembly. Examples of sensors configured to detect the movement of the gripping assembly are described below in relation to Figures 9 to 15. Generally, the sensor has an input that is engaged by the movement of the gripping assembly. In step 730, the controller is used to determine the vertical position of the gripping assembly using the output of the sensor. It will be understood that the detected movement of the gripping assembly can be correlated to its vertical position. For example, if it is detected that the tether (or FFC) has been unwound 1 meter from the lifting assembly, the vertical position of the gripping assembly has changed by 1 meter relative to that. If the starting position of the gripping assembly for a 1-meter unwinding is absolutely known (for example, determined from when the gripper device is fully retracted into the container receiving space 40 of the load handling device 30 located on the grid storage framework 14), then the current absolute vertical position of the gripper assembly can be determined. In an optional step 740, a controller is used to control / adjust the motion profile of the gripping assembly based on the determined vertical position. Typically, a motor is controlled using the motion profile. In the example of the load handling device, a motor controls the raising and / or lowering of the container gripping assembly according to the motion profile.One such example is a trapezoidal velocity-time motion profile, which should result in a container gripping assembly being in a specific vertical position at a given time. By monitoring this vertical position, it is possible to provide feedback used to control / adjust the motion profile.

[0061] An exemplary container lifting assembly (further described in PCT application PCT / EP2022 / 081364 (Ocado)) is shown in Figure 8. In Figure 8, the container lifting assembly 800 has a lifting assembly 802 including four spools 810 for winding and unwinding each tether 38. A drive belt 820 is driven by a motor (not shown) which rotates the spools on the drive shaft 805 in the opposite direction to the drive shaft 806. By rotating the drive shafts 805 and 806 in opposite directions, each tether 38 can be positioned at or near the corners of the lifting assembly. In particular, as shown in Figure 8, the point where each tether is wound onto or unwound from the spool is at or near each corner of the lifting assembly. This allows the tethers to connect to the container gripping assembly 39 at each corner of the container gripping assembly, which increases stability when raising and lowering the container gripping assembly 39.

[0062] The tether may be a cable, or a rope, or a tape, or any other form of tether having the physical properties necessary to lift a container. In one implementation, four tethers are used. In one implementation, the tether may comprise a steel tape. In one implementation, the tether may be formed from or comprise a polyester material (e.g., a polyester woven material). In particular, the tether may comprise a woven polyester tape or belt, such as a seat belt (i.e., a seat belt may be used as a tether). In another implementation, the tether is made of Dyneema RTMTapes and other materials can be made from ultra-high molecular weight polyethylene, UHMVPE, or UHMW (high modulus polyethylene, also known as HMPE). In another implementation, the tether is made from Dyneema. RTM The tether may comprise a polyester material (e.g., a polyester fabric) combined with the tape. In another implementation, the tether may comprise a cotton material. In another implementation, the tether may comprise a webbing material such as webbed polyester, nylon, or cotton. In another implementation, the tether may comprise a conductive material; for example, the tether may comprise a woven material or woven polyester material in which conductive elements or wiring (e.g., copper) are woven into the tether's fabric or cloth. In another implementation, the tether may comprise a woven belt (e.g., a seat belt) having conductive elements or wiring woven into the belt. In another implementation, the tether may comprise conductive elements or wiring (e.g., copper) woven into the tether's fabric or cloth to provide power and / or communication (i.e., telecommunication) to the gripping device.

[0063] Furthermore, as described above with respect to Figure 4, an optional fixed flexible cable (or ribbon cable), FFC, 830, and FFC spool 840 are also shown for communicating electrical signals to the gripper assembly 39 in order to supply power to the container grip and control the container grip. That is, the FFC is used to supply power to and control a pin or clip that engages with the bin 10 by a suitable drive mechanism housed within the container gripping assembly 39. One suitable FFC is Axon'Cable RTM It is manufactured by [manufacturer name]. Although FFC is shown, it will be understood that at least one wire may be used instead for the same purpose, or the conductive element may be integrated with the tether as described above.

[0064] A system that uses the method shown in Figure 7 to determine the vertical position of the container gripping assembly is described below. The lifting assembly shown in Figure 8 (and Figure 9 below) is shown having four spools 810 and their respective tethers that raise and lower the container gripping assembly using the configuration shown, but it should be understood that the system described below is not limited to a specific number of spools, tethers, and configurations shown for raising and / or lowering the container gripping device.

[0065] Referring to Figures 9, 10, 11A, and 11B, a container lifting assembly 900 is described which has a sensor capable of determining the vertical position of the container gripping assembly. Similar to Figure 8, the lifting assembly includes four spools 910 for winding and unwinding each tether 38. A drive belt 920 is driven by a motor 901 (via drive belt 925 and spool 911) to rotate the spools on the drive shaft 905 in the opposite direction to the drive shaft 906. The drive belt 920 drives pulleys connected to the spools 910. By rotating the drive shafts 905 and 906 in opposite directions, each tether 38 can be positioned at or near the corners of the lifting assembly. In particular, as shown in Figure 9, the points where each tether is wound onto or unwound from the spool are at or near the respective corners of the lifting assembly. This allows the tether to connect to the container gripping assembly 39 (not shown) at each corner of the container gripping assembly, thereby improving stability when raising and lowering the container gripping device 39. The container lifting assembly also includes an FFC spool 940. An FFC (not shown) is wound onto the spool and extends to the container gripping assembly 39 to transmit electrical signals to the container gripping assembly 39. Thus, the FFC is wound up and unwound as the motor rotates the drive shaft 906. The stator 960 is used to send signals to and receive signals from the FFC on the FFC spool 945.

[0066] In one implementation, the FFC spool 940 has a rotary encoder 950 (i.e., a sensor) for detecting the movement of the FFC spool 940. As an example, the rotary encoder 950 may be held in a position between the stator and the horizontal bar 925 (however, other means of interface the rotary encoder 950 with the FFC spool are apparent). The rotary encoder 950 comprises a rotary electromechanical device that generates pulses when the FFC spool rotates. For example, pulses are generated for a predetermined amount of angular rotation of the FFC spool. As shown in Figures 11A and 11B, the encoder device 1000 has an encoder disk 945 mounted on the FFC spool 840 / 940. The encoder disk 945 has slots 946 around its periphery (or outer circumference). The slots allow the transmitter and receiver elements 951 of the encoder 950 to transmit and receive optical signals. Solid space between the slots prevents the reception of optical signals. Therefore, the optical signal is received and interrupted as the FFC spool rotates, which can be correlated with the angular rotation of the FFC spool 940. Although an optical rotary encoder has been described, a mechanical encoder can be used as an alternative if the FFC spool 940 directly engages with the input of a mechanical encoder to rotate the input. Alternatively, the motor 920 may have an encoder that can be used to determine the rotational speed of the FFC spool 940. Regardless of the type of rotary encoder implementation, the angular rotation and direction of the FFC spool 940 can be determined as the container gripping assembly 39 moves up and down.

[0067] Using the dimensions of the FFC spool 940 and the FFC, the angular rotation and direction of the FFC spool 940 can be correlated to the length of the FFC currently extending from the FFC spool. The length of the FFC currently extending from the FFC spool 940 can be correlated to the vertical position of the container gripping assembly, as described above with respect to Figure 7.

[0068] While the use of the rotary encoder 950 for use with the FFC spools 840 / 940 has been described, it will be understood that either of the tether spools 810 / 910 can be monitored using the encoder device 1100 shown in Figures 11A and 11B. That is, an encoder disk is mounted on the tether spool 810 / 910. Thus, the rotation of the tether spool 910 can be monitored instead. Using the dimensions of the tether spool 910 and the tether 38, the angular rotation of the tether spool 910 can be correlated to the length of the tether currently extending from the tether spool 910, which can be correlated to the vertical position of the container gripping assembly, as described above with respect to Figure 7. Alternatively, the motor 901 may have a motor encoder that can be used to determine the rotational speed of the tether spool 910. Regardless of the type of rotary encoder implementation, the angular rotation and direction of the tether spool 910 can be determined as the container gripping assembly 39 moves up and down.

[0069] As shown in Figures 11A and 11B, it will also be understood that the encoder devices 1100 can be used to monitor each tether spool 810 / 910 and FFC spool 840 / 940. Using two encoder devices 1100 provides redundancy in case one of the encoder devices fails. Using two encoder devices 1100 on each tether spool 910 allows for the determination of whether the container gripping assembly 39 is horizontal during lifting or raising operations. If the two encoder devices 1100 detect the same angular rotation of each tether spool 910, it can be inferred that the container gripping assembly 39 is horizontal. This can occur if one tether spool slips on the shaft it rotates on. One of the encoder devices 1100 having an output that deviates from the other encoder device 1100 can indicate that the container gripping assembly 39 is not horizontal. Using four encoder devices 1100 allows for the detection of the orientation of the container gripping assembly.

[0070] Using the FFC spool 940 to determine the vertical position of the container lifting assembly may be advantageous if the FFC has a relatively higher modulus of elasticity than the tether 39, for example, if a polyester woven belt is used for the tether 39. The polyester woven belt tends to stretch during unwinding and winding depending on the load carried by the container gripping assembly 39. Similarly, the polyester woven belt tends to unwind from and wind onto the spool 910 in an unpredictable manner. In comparison, the FFC has less tendency to stretch and unwinds from and winds onto the FFC spool in a predictable manner, so the detected movement of the FFC spool results in a more accurate determination of the vertical position of the container lifting assembly 39.

[0071] Additionally or alternatively, the FFC spool 940 may be rotatably mounted on the shaft 906, for example via a bearing, so that the FFC spool 940 can rotate independently of or relative to the shaft 906. Thus, the FFC spool 940 allows the FFC cable to extend when the tether is unwound and lowers the container gripping assembly 39. Furthermore, the FFC does not support the load of the container gripping assembly 39. A biasing assembly can be used to ensure that the FFC is unwound onto the FFC spool 940 when the container gripping assembly 39 rises. The biasing assembly resists the unwinding of the FFC so that the FFC remains taut, thereby ensuring a more accurate determination of the vertical position of the container gripping assembly 39. For example, if the FFC is determined to be 1 meter extended from the FFC spool 940 and the FFC is determined to be taut, then it can be determined that the position of the container gripping assembly has changed by 1 meter. As shown in Figure 10, the biasing assembly comprises a biasing plate 960 and a torsion spring 930 acting on an FFC spool 940 rotatably mounted on a shaft 906. The biasing plate 960 is fixedly mounted on the shaft 906. The torsion spring 930 is connected to the biasing plate 960 and the FFC spool 945 so as to counteract the unwinding of the FFC spool 945. In other words, the FFC spool 945 is spring-loaded so as to counteract a rotational force applied to the stationary shaft 925 in the unwinding direction (within the elastic limit of the torsion spring). Thus, the FFC spool unwinds (within the elastic limit of the torsion spring) when this rotational force is removed. In general, any biasing assembly can be used as long as it acts on the rotatably mounted FFC spool 940 to maintain the FFC in a tensioned state. For example, a tension spring can be used to connect the biasing plate 960 and the FFC spool 945. Alternatively, the FFC spool 945 may be fixedly mounted to the shaft 906, and the biasing device may be located within the container gripping assembly 39. In this implementation, the biasing device resists the winding of the FFC spool 940.This ensures that the FFC remains taut during the raising and lowering of the container gripping assembly 39.

[0072] Referring to Figure 12, another sensor 1200 is described which can determine the vertical position of the container gripping assembly. The spool, which may be one of spools 810 / 910 / 840 / 940, is used to wind up and / or unwind the respective tether 38 or FFC 830. The rotary encoder wheel 1210 is biased against the tether 38 or FFC 830 using the arm 1220, and the wheel 1210 rotates via the pivot 1215. As shown in Figure 12, the rotary encoder wheel 1210 rotates as the tether 38 or FFC 830 moves during winding up and / or unwinding from the spool 810 / 910 / 840 / 940. That is, the shaft / input of the rotary encoder wheel is rotated by the tether 38 or FFC 830. The rotation of the encoder wheel 1210 can be correlated to the length of the tether 38 or FFC830 that caused the rotation, and then, according to the implementation described above, to the vertical position of the container gripping assembly. The encoder wheel may be part of an optical encoder or a mechanical encoder.

[0073] Referring to Figure 13, another sensor 1300 capable of determining the vertical position of the container gripping assembly is described. The spool 1310 can be mounted on shafts 805 / 806 / 905 / 906. Thus, the spool 1310 rotates as the lifting assembly raises and lowers the container gripping assembly. The spool 1310 may be conductive. Additionally or alternatively, the spool 1320 has channels or grooves that allow conductive wires 1320 to be wound so that wires in adjacent channels / grooves are in physical contact. This means that in a fully wound spool 1310, the conductive wires 1320 are short-circuited, and a voltage applied between the first end of the conductive wire 1320 (connected to the spool) 1310 and the second end (connected to the container gripping assembly) returns a given current value. When the spool 1310 is unwound, the length of the conductive wires 1320 is no longer short-circuited, as shown in Figure 13. Therefore, the voltage applied between the first and second ends of the conductive wire 1320 returns a reduced current value due to the increased electrical resistance of the conductive wire 1320's construction. In one implementation, the second end can be connected to an FFC connection on the container gripping assembly 39 to form a closed circuit that allows for the determination of the current value. The change in electrical resistance as the conductive wire 1320 is wound and unwound can be correlated to the length of the conductive wire (and thus the tether 38 or FFC 830) that caused the change in electrical resistance, and then to the vertical position of the container gripping assembly according to the implementation described above. A biasing assembly (such as the one described above with respect to the FFC spool) can be used with the spool 1310, provided that the biasing assembly maintains the spool in a tensioned state. That is, the biasing assembly resists the winding or unwinding of the spool 1310, as described above with respect to the FFC spool.

[0074] Referring to Figure 14, another sensor 1400 is described that can determine the vertical position of the container gripping assembly. Figure 14 shows the same configuration as described above with respect to Figure 8. The description of Figure 8 applies to what is shown in Figure 8. In addition, a time-of-flight (ToF) sensor 1410 is attached to the container lifting assembly 39. The ToF sensor 1410 is configured to transmit an optical signal 1420 to a reflective surface (not shown) and to receive a reflection 1430 of the transmitted optical signal 1420. The distance between the container lifting assembly 39 and the reflective surface can be calculated using the time between the transmission and reception of the optical signal (e.g., laser or LED). The reflective surface does not move when the container lifting assembly 39 is raised and / or lowered. For example, the reflective surface may be located on the lifting mechanism 802 or any other suitable part of the cargo handling device or system. Thus, the vertical position of the container gripping assembly 39 can be determined using the distance between the container lifting assembly 39 and the reflective surface. It should be understood that the ToF sensor 1410 can instead be located in a fixed position within the lifting mechanism 802 or any other suitable part of the load handling device or system, and can transmit and receive optical signals onto the reflective surface of the container lifting assembly 39. Suitable ToF sensors are available from Texas Instruments. RTM This is the OPT3101ToF-based Long Range Proximity and Distance Sensor AFE Evaluation Module. Generally, any laser sensor capable of measuring distance can be used. In principle, this implementation can utilize any rangefinder type sensor, such as optical detection and ranging, LiDAR, or ultrasonic, to implement the ToF sensor.

[0075] Referring to Figure 15, another sensor 1500 is described which can determine the vertical position of the container gripping assembly. The spool, which may be one of spools 810 / 910 / 840 / 940, is used to wind up and / or unwind the respective tether 38 or FFC 830. The wheel 1510 is biased against the spool 810 / 910 / 840 / 940 using the arm 1520, and the wheel 1510 rotates via the pivot 1515. As shown in Figure 15, when the spools 810 / 910 / 840 / 940 rotate, the wheel 1510 rotates. The wheel 1510 has an outer textured surface that allows the sensor 1530 to track its movement. One such suitable surface is aluminum or nylon. The sensor 1530 projects an optical signal (laser or LED, etc.) onto the outer textured surface of the spool 1510 so that it can detect reflected light 1550 (e.g., via a photodiode) to track the movement of the outer textured surface of the spool 1510. This operation is similar to that of an optical computer mouse. The detected movement of the outer textured surface of the spool 1510 can be correlated with the rotation of the spools 810 / 910 / 840 / 940, and therefore with the extension of the tether 39 or FFC 820, which can then be correlated with the vertical position of the container gripping assembly, in accordance with the implementation described above. It will be understood that the wheel 1510 may be omitted if the spool 810 / 910 / 840 / 940 instead has a surface that allows the sensor 1530 to track its movement.

[0076] Referring to Figure 16, a system using the aforementioned sensors to determine a fault in the container gripping assembly 39 is illustrated. Motor 901 retracts and untracts the tethers 38 / 830. Therefore, any of the above sensors directly monitoring the motor can actually detect whether the motor is currently operating, and thus whether the tethers are retracted or untracted. In other words, if the motor is operating, any of the above sensors directly monitoring the motor can detect the motor's operation. If the container gripping assembly 39 is faulted, the motor will continue to retract and / or untract the tethers, while the tethers 38 / 830 and / or FFC830 will experience a change in configuration. For example, if the container gripping assembly 39 collides with a fault during its descent, the tethers 38 / 830 and / or FFC830 will loosen. Therefore, the sensors described above, which can detect changes in the state of the tethers 38 / 830 and / or FFC830, can be used in conjunction with sensors that detect the state of motor 901 to determine a fault in the container gripping assembly 39. In particular, if the motor is operating in a manner that can be detected by a specific sensor, and the tether 38 / 830 and / or FFC830 is loosened in a manner that can be detected by a specific sensor, it can be inferred that a failure has occurred in the gripping assembly 39. That is, if there is a failure when lowering the container gripping assembly, the motor will no longer cause the container gripping assembly 39 to lower.

[0077] The processor / controller 1610 (which may be the same as the processor / controller 650) can receive input from the motor start sensor 1620. The sensor 1620 includes the sensors described above: Motor encoder for motor 910 • FFC or tether spool 810 / 910 / 840 / 940 monitored using an encoder device 1100 as shown in Figures 11A and 11B • As shown in Figure 15

[0078] All of the sensors 1620 either directly detect the motor operation itself or detect it via the movement of a spool (either an FFC or a tether spool 810 / 910 / 840 / 940) fixed to a shaft rotated by the motor. Generally, the motor start sensor 1620 indicates whether the motor is activated and winding and / or unwinding the tether 38 / 830. If the motor is rotating the shaft from which the tether / FFC is wound and / or unwound, it is assumed that the container lifting assembly 39 is being raised and / or lowered.

[0079] The processor / controller 1610 can receive different inputs to verify that the container lifting assembly 39 is actually rising and / or falling. One input that may be used for this purpose is provided by a sensor 1630 that detects movement of the gripping assembly. Sensor 1630 includes the sensors described above: Figure 10 shows the FFC spool 940, encoder 950, and biasing device. • As shown in Figure 12 • The device shown in Figure 13 and the biasing device • As shown in Figure 14 • As shown in Figure 15 when used with the FFC spool 940 / 940 and biasing device.

[0080] The output of sensor 1630 depends on the movement of the container gripping assembly 39. That is, sensor 1630 can indicate, to the extent possible, the degree to which the container gripping assembly 39 is being raised and / or lowered. Thus, the processor / controller 1610 can determine whether the motor operation (indicated via sensor 1620) actually results in the raising and / or lowering of the container lifting assembly 39 (indicated via sensor 1630).

[0081] Alternatively, a given sensor 1630 can indicate, to the extent possible, the degree to which the container gripping assembly 39 is being raised and / or lowered, and the processor / controller 1610 can correlate the output of sensor 1630 with a motor motion profile used to control the raising and / or lowering of the container gripping assembly 39. That is, the processor / controller 1610 can determine whether the current raising and / or lowering of the container gripping assembly 39 (indicated via sensor 1630) correlates with that controlled by the motor. For example, a trapezoidal motion profile of a motor mapping time to the velocity of the container gripping assembly 39 can be converted by the controller into a corresponding time-versus-distance profile. From the converted time-versus-distance profile, the deviation of the container gripping assembly 39 from a determined vertical position can be detected.

[0082] Generally, the system in Figure 16 can be used to determine a mismatch between the motor's drive and the resulting upward and / or downward movement of the container gripping assembly. The presence of such a mismatch can be detected using the method in Figure 17.

[0083] Figure 17 shows steps of Method 1700 for use in a lifting assembly (such as one used in a cargo handling device or crane), comprising a gripping assembly configured to grip a load, a lifting assembly configured to raise and lower the gripping assembly, the lifting assembly having at least one tether connected to the gripping assembly, and a motor for winding up and / or unwinding the tether around at least one shaft to raise and / or lower the gripping assembly. It should be understood that the Method of Figure 17 may be performed using a controller (e.g., controller 650 of the cargo handling device in Figure 6). Step 1710 rotates at least one shaft (805, 906, 905, 906, etc.) so that a motor (e.g., motor 901) winds up and / or lowers the gripping assembly (e.g., container gripping assembly 39), and winds up and / or unwinds the tether (e.g., tether 38, etc.). In step 1720, a sensor (such as sensor 1630) is used to detect movement of the gripping assembly. An example of sensor 1630 configured to detect movement of the gripping assembly is described above in relation to Figures 9 to 15. In step 1730, the controller is used to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the winding and / or unwinding of the tethers around the shaft or each shaft for raising and / or lowering the gripping assembly. That is, the controller determines a mismatch between the motor drive and the resulting raising and / or lowering of the gripping assembly. An example of how step 1730 is performed using sensor 1620 and / or input 1640 is shown below.

[0084] In the optional step 1740, the controller is used to stop the motor when it determines that there is a failure in the gripping assembly. This means that the tether is not further wound up and / or unwound, and thus damage to the gripping device (container gripping assembly 39, etc.) and / or the lifting device (container lifting assembly 39, etc.) and / or the surrounding environment (grid storage structure 14, etc.) is avoided.

[0085] In one implementation of the method shown in Figure 17, sensor 1620 is a motor encoder for a motor (such as motor 901), and the controller is configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the motor encoder. As a mere example, both the motor encoder and sensor 1630 may be configured to produce a corresponding output for each increment of rotation of at least one shaft. Thus, the deviation in the outputs between the motor encoder (i.e., sensor 1620) and sensor 1630 can be used to indicate that the shaft rotation is no longer causing the lifting assembly to rise and / or fall. The controller may be configured to determine a failure of the grid assembly when the current output of sensor 1630 does not correlate with the current output of the motor encoder by a threshold. The threshold can, of course, be set to allow small deviations before a failure is determined. For example, the threshold may require that two subsequent outputs be different.

[0086] In another implementation of the method in Figure 17, a tether spool (such as spool 810 / 910) is used for each of the tethers from which the tethers are wound and / or unwound. Each of the tether spools is fixedly mounted on a shaft rotated by a motor. Sensor 1620 is a tether rotary encoder for each of the tether spools. Each of the tether rotary encoders is configured to engage with each of the spools to detect the degree to which each of the spools has rotated as each of the tethers is wound and / or unwound. Any of the rotary encoders described above, such as those shown in Figures 11A and 11B, can be used as the tether rotary encoders. The controller is configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of each of the tether rotary encoders. As just one example, both the tether rotary encoder and sensor 1630 may be configured to produce a corresponding output for each increment of rotation of at least one shaft. Therefore, the deviation of the output between the aforementioned or each tether rotary encoder (i.e., sensor 1620) and sensor 1630 can be used to indicate that shaft rotation no longer causes the lifting assembly to rise and / or fall. The controller may be configured to determine a failure of the gripping assembly if the current output of sensor 1630 does not correlate with the current output of the tether rotary encoder by a threshold. The threshold can, of course, be set to allow small deviations before a failure is determined. For example, the threshold may require that two subsequent outputs be different.

[0087] In another implementation of the method in Figure 17, an electrical cable spool (e.g., FFC spool 840 / 940) is used on which electrical cables (e.g., FFC 830) are unwound and wound. The electrical cable spool is fixedly mounted on a shaft rotated by a motor. The electrical cable spool is connected to and electrically communicates with a gripping assembly. Sensor 1620 is an electrical cable rotary encoder for the electrical cable spool. The electrical cable rotary encoder is configured to engage with the spool or each spool to detect the degree to which the spool or each spool has rotated when the tether or each respective tether is wound and / or unwound. Any of the above rotary encoders, such as those shown in Figures 11A and 11B, can be used as an electrical cable rotary encoder. The controller is configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the tether rotary encoder. As just one example, both the electrical cable rotary encoder and sensor 1630 may be configured to produce a corresponding output for each increment of rotation of at least one shaft. Therefore, the deviation of the output between the electrical cable rotary encoder (i.e., sensor 1620) and sensor 1630 can be used to indicate that the rotation of the shaft is no longer causing the lifting assembly to rise and / or fall. The controller may be configured to determine a fault in the grid assembly if the current output of sensor 1630 does not correlate with the current output of the electrical cable rotary encoder by a threshold. The threshold can, of course, be set to allow small deviations before a fault is determined. For example, the threshold may require that the two subsequent outputs be different.

[0088] In another implementation of the method in Figure 17, a tether spool (e.g., spool 810 / 910) is used for each of the tethers from which the tethers are wound and / or unwound. Each of the tether spools is fixedly mounted to a shaft rotated by a motor. Sensor 1620 comprises a tether spool sensor having a light source and a photodetector as described above and shown in Figure 15. As described above, the light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly is raised and / or lowered. The photodetector is configured to detect the reflection of the optical signal from the surface to detect the movement of the surface. The lifting assembly comprises wheels that contact the tether spool from which the tethers are wound and / or unwound, wherein the wheels have a surface, or alternatively, each of the electrical cable spools has a surface. The controller is configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the tether spool sensor. As a mere example, both the tether spool sensor and sensor 1630 can be configured to produce a corresponding output for each increment of rotation of at least one shaft. Thus, the deviation of the output between the aforementioned or each tether spool sensor (i.e., sensor 1620) and sensor 1630 can be used to indicate that the shaft rotation is no longer causing the lifting assembly to rise and / or fall. The controller may be configured to determine a failure of the gripping assembly if the current output of sensor 1630 does not correlate with the current output of the tether spool sensor by a threshold. The threshold can, of course, be set to allow small deviations before a failure is determined. For example, the threshold may require that two subsequent outputs be different.

[0089] In another implementation of the method in Figure 17, an electrical cable spool (e.g., FFC spool 840 / 940) is used on which an electrical cable (e.g., FFC 830) is unwound and wound. The electrical cable spool is fixedly mounted on a shaft rotated by a motor. The electrical cable spool is connected to and electrically communicates with a gripping assembly. Sensor 1620 comprises an electrical cable spool sensor comprising a light source and a photodetector, as described above and shown in Figure 15. As described above, the light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly is raised and / or lowered. The photodetector is configured to detect the reflection of the optical signal from the surface to detect the movement of the surface. The lifting assembly comprises a wheel that contacts the electrical cable spool on which the electrical cable spool is wound and / or unwound, wherein the wheel comprises the surface, or alternatively, the electrical cable spool comprises the surface. The controller is configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the electrical cable spool sensor. As just one example, both the electrical cable spool sensor and sensor 1630 can be configured to produce a corresponding output for each increment of rotation of at least one shaft. Thus, the deviation of the output between the electrical cable spool sensor (i.e., sensor 1620) and sensor 1630 can be used to indicate that the rotation of the shaft is no longer causing the lifting assembly to rise and / or fall. The controller may also be configured to determine a failure of the gripping assembly if the current output of sensor 1630 does not correlate with the current output of the electrical cable spool sensor by a threshold. The threshold can, of course, be set to allow for small deviations before a failure is determined. For example, the threshold may require that the two subsequent outputs be different.

[0090] The five implementations described above use a sensor 1620 that directly indicates motor operation in a processor controller that implements the method shown in Figure 17.

[0091] Additionally or alternatively, the controller may receive a motion profile so that it can derive the expected state of the gripping assembly; that is, the controller is instructed how the gripping assembly should move. As described above, the motion profile of the motor may be provided to the controller, mapping time to the velocity of the container gripping assembly 39. A corresponding time-versus-distance profile may be provided instead, or may be derived from the motion profile by the processor. Thus, as soon as the controller detects movement of the gripping assembly via the sensor 1630, the controller can compare the movement of the gripping assembly to the expected movement according to that derived from the motion profile. This can be used to further verify that a fault has occurred, if input 1640 is used in addition to input 1620.

[0092] The method shown in Figure 17 also uses sensor 1630, an example of which is described below.

[0093] In one implementation of the method shown in Figure 17, an electrical cable spool (such as FFC spool 840 / 940) is used on which an electrical cable (such as FFC 830) is unwound and wound. The electrical cable spool is rotatably mounted on a motor-driven shaft, such as the FFC spool 940 and biasing device shown in Figure 9, as described above. The electrical cable spool is connected to and electrically communicates with the gripping assembly. Sensor 1630 is equipped with a rotary encoder, such as encoder 950. When the gripping assembly is obstructed, the FFC spool 940 in Figure 9 returns to its biased state. That is, the FFC spool and FFC are no longer subjected to the pull of the movement of the container lifting assembly and snap back to their biased state. The return to the biased state means that the rotary encoder output of sensor 1630 in this implementation no longer correlates with the output provided by sensor 1620, and the obstruction is detected as described above. Additionally or alternatively, the vertical position of the gripper assembly can be derived from sensor 1630 in this implementation and compared with the input provided by 1640 to determine faults.

[0094] In another implementation of the method in Figure 17, the sensor 1630 includes a rotary encoder, such as the encoder 1210 described above and shown in Figure 12. When the gripping assembly is obstructed, the rotary encoder 1210 in Figure 12 no longer rotates due to a reduction in the traction force with either the tether 38 or the FFC 830. The loss of traction force means that the rotary encoder output of the sensor 1630 in this embodiment no longer correlates with the output provided by the sensor 1620, and the obstruction is detected as described above.

[0095] In another implementation of the method in Figure 17, a wire spool (such as wire spool 1310) is used on which the wire (such as wire 1320) is unwound and wound. The wire spool is rotatably mounted on a motor-driven shaft, such as the wire spool 1310 and biasing device shown above and in Figure 13. The wire spool is connected to a gripping assembly. Sensor 1630 comprises sensor 1300. When the gripping assembly is obstructed, the wire spool 1310 in Figure 13 returns to its biased state. That is, the wire spool 1310 is no longer subjected to the pull of the movement of the container lifting assembly and snaps back to its biased state. The return to the biased state means that the output of sensor 1300 in this implementation no longer correlates with the output provided by sensor 1620, and the obstruction is detected as described above. Additionally or alternatively, the vertical position of the gripper assembly can be derived from sensor 1630 in this implementation and compared with the input provided by 1640 to determine faults.

[0096] In another implementation of the method in Figure 17, sensor 1630 comprises a ToF sensor as described above and shown in Figure 14 (ToF sensor 1410, or generally any laser sensor that measures distance can be used). When the gripping assembly is obstructed, the ToF sensor no longer detects a change in distance. Alternatively, the gripper assembly can be tilted to such an extent that the ToF sensor no longer detects a reflected light signal due to the loss of alignment with the reflective surface. The absence of a change in the distance measurement or a reflected light signal means that the output of sensor 1630 in this implementation no longer correlates with the output provided by sensor 1620, and the obstruction is detected as described above. Additionally or alternatively, the vertical position of the gripper assembly can be derived from sensor 1630 in this implementation and compared with the input provided by 1640 to determine the obstruction.

[0097] In one implementation of the method shown in Figure 17, an electrical cable spool (such as an FFC spool 840 / 940) is used on which an electrical cable (such as an FFC 830) is unwound and wound. The electrical cable spool is rotatably mounted on a motor-driven shaft, such as the FFC spool 940 and biasing device shown above and in Figure 9. The electrical cable spool is connected to and electrically communicates with a gripping assembly. Sensor 1630 comprises an electrical cable spool sensor comprising a light source and a photodetector, as shown above and in Figure 15. As described above, the light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly is raised and / or lowered. The photodetector is configured to detect the reflection of the optical signal from the surface to detect the movement of the surface. The lifting assembly comprises wheels that contact the electrical cable spool on which the electrical cable is wound and / or unwound, wherein the wheels comprise the surface, or alternatively, wherein the electrical cable spool comprises the surface. When the gripping assembly is obstructed, the FFC spool 940 in Figure 9 returns to its biased state. That is, the FFC spool and FFC are no longer subjected to the pull caused by the movement of the container lifting assembly and snap back to their biased state. The return to the biased state means that the rotary encoder output of sensor 1630 in this implementation no longer correlates with the output provided by sensor 1620, and a fault is detected as described above. Additionally or alternatively, the vertical position of the gripper assembly can be derived from sensor 1630 in this implementation and compared with the input provided by 1640 to determine a fault.

[0098] In this document, the phrase "movement in the n direction" (and related expressions) where n is one of x, y, and z is intended to mean movement substantially along or parallel to the n-axis in either direction (i.e., towards the positive end of the n-axis or towards the negative end of the n-axis).

[0099] In this document, the term “connect” and its derivatives are intended to include the possibility of direct and indirect connection. For example, “x is connected to y” is intended to include the possibility that x is directly connected to y without any intervening components, and the possibility that x is indirectly connected to y with one or more intervening components. When direct connection is intended, the terms “directly connected,” “direct connection,” or similar terms are used. Similarly, the term “support” and its derivatives are intended to include the possibility of direct and indirect contact. For example, “x supports y” is intended to include the possibility that x directly supports y and directly contacts y without any intervening components, and the possibility that x indirectly supports y with one or more intervening components that contact x and / or y. The term “attach” and its derivatives are intended to include the possibility of direct and indirect attachment. For example, the statement "x is attached to y" is intended to include both the possibility that x is directly attached to y without any intervening components, and the possibility that x is indirectly attached to y with one or more intervening components.

[0100] In this specification, the term “to comprise” and its derivatives are intended to have an inclusive, rather than exclusive, meaning. For example, “x comprises y” is intended to include the possibility that x comprises one and just one y, multiple ys, or one or more ys and one or more other elements. When an exclusive meaning is intended, the phrase “x consists of y” is used, meaning that x comprises only y and nothing else.

[0101] In this specification, “controller” is intended to include any hardware suitable for controlling (e.g., providing instructions to) one or more other components. For example, a processor with one or more memories and appropriate software processes data about one or more components and sends appropriate instructions to the components so that the components can perform their intended functions.

[0102] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural form unless explicitly stated otherwise. It will be further understood that the terms “equipped with” and / or “equipped with” as used herein specify the presence of the described feature, integer, step, action, element, and / or component, but do not exclude the presence or addition of one or more other features, integers, steps, actions, elements, components, and / or groups thereof.

[0103] The present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment that includes both hardware and software elements. In a preferred embodiment, the present invention is implemented in software.

[0104] Furthermore, the present invention may take the form of a computer program embodied as a computer-readable medium having computer-executable code for use by or with a computer. For the purposes of this description, the computer-readable medium may be any tangible device that can store, communicate, propagate, or transfer a program for use by or with a computer. Furthermore, the computer-readable medium may be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device), or a propagation medium. Examples of computer-readable mediums include semiconductor or solid memory, magnetic tape, removable computer diskettes, random access memory (RAM), read-only memory (ROM), rigid magnetic disks, and optical disks. Current examples of optical disks include compact disks-read-only memory (CD-ROM), compact disks-read / write (CD-R / W), and DVDs.

[0105] The flowchart in the drawings illustrates the architecture, functionality, and operation of possible implementations of the methods according to various embodiments of the present invention. In this regard, each block in the flowchart may represent a module, segment, or part of code comprising one or more executable instructions for implementing a specified logical function. Note that in some alternative implementations, the functions shown in the blocks may be performed in a different order than shown in the diagram. For example, two blocks shown consecutively may actually be executed substantially simultaneously, or the blocks may be executed in reverse order depending on the functionality involved. Note that each block in the flowchart, and any combination of blocks in the flowchart, may be implemented by a dedicated hardware-based system that performs a specified function or operation, or a combination of dedicated hardware and computer instructions.

[0106] The above description is given only as an example, and it will be understood that various modifications can be made by those skilled in the art. Although various embodiments have been described above with some degree of specificity or by reference to one or more individual embodiments, those skilled in the art can make numerous modifications to the disclosed embodiments without departing from the scope of the invention. The original claims of this application are listed below. [1] A lifting assembly for raising a container from a stack of containers in a grid storage structure and / or lowering a container into a stack of containers, wherein the lifting assembly is A gripping assembly configured to grip a load, The gripping assembly comprises a lifting assembly configured to raise and lower the gripping assembly, and the lifting assembly is At least one tether connected to the gripping assembly, The lifting assembly further comprises a motor for winding up and / or unwinding the tether or each tether in order to raise and / or lower the gripping assembly, wherein the lifting assembly further comprises A sensor configured to detect the movement of the gripping assembly, wherein the sensor has an input that varies with the movement of the gripping assembly. A lifting assembly comprising: a controller configured to determine the vertical position of the gripping assembly using the output of the sensor. [2] The lifting assembly comprises an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to be retracted and / or untracted when the gripping assembly is raised and / or lowered, Herein, the lifting assembly according to [1], wherein the sensor is configured to detect the extent to which the electrical cable is wound up and / or unwound. [3] The lifting assembly according to [2], further comprising an electrical cable spool from which the electrical cable is wound and / or unwound, wherein the sensor comprises a rotary encoder configured to engage with the electrical cable spool to detect the degree to which the electrical cable spool has rotated as the electrical cable is wound and / or unwound. [4] The lifting assembly according to [2] or [3], wherein the electrical cable has a higher modulus of elasticity than the above or each tether. [5] The lifting assembly according to any one of [2] to [4], further comprising a tether spool for the or each tether from which the or each tether is wound up and / or unwound, wherein the electrical cable spool and the or each tether spool are mounted on a shaft so that the electrical cable spool rotates relative to the or each tether spool. [6] The lifting assembly according to any one of [2] to [5], further comprising a biasing assembly configured to resist the unwinding or winding of the electrical cable spool so that the electrical cable is tensioned between the lifting assembly and the gripping assembly. [7] The lifting assembly according to any one of [2] to [6], wherein the electrical cable transmits an electrical signal to the gripping assembly. [8] The lifting assembly according to any one of [2] to [7], wherein the electrical cable comprises a fixed flexible cable, an FFC, or a ribbon cable. [9] The lifting assembly according to [1], wherein the sensor comprises a motor encoder for the motor, wherein the motor encoder is configured to detect the extent to which the or each tether is wound up and / or unwound.

[10] The lifting assembly according to [9], further comprising a tether spool for the or each tether on which the or each tether is wound and / or unwound, wherein the motor encoder detects the degree to which the or each tether spool has rotated when the or each tether is wound and / or unwound.

[11] The lifting assembly according to [1], comprising a rotary encoder configured to detect the extent to which the or each tether is retracted and / or unwinded.

[12] The lifting assembly according to

[11] , further comprising a tether spool for the or each tether from which the or each tether is wound and / or unwound, wherein the sensor comprises a rotary encoder for the or each tether spool, wherein the or each rotary encoder is configured to engage with the or each spool to detect the degree to which the or each spool has rotated when the or each tether is wound and / or unwound.

[13] The lifting assembly according to [1], wherein the sensor comprises a rotary encoder for the or each tether, wherein the rotary encoder is configured to contact each tether such that the winding and / or unwinding of the or each each tether rotates the input of the rotary encoder.

[14] The lifting assembly comprises an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to be retracted and / or untracted when the gripping mechanism is raised and / or lowered, The lifting assembly according to [1], wherein the sensor comprises a rotary encoder, wherein the rotary encoder is configured to engage with the electrical cable such that the winding and / or unwinding of the or each tether rotates the shaft of the rotary encoder.

[15] The lifting assembly according to

[13] or

[14] , further comprising a biasing assembly configured to bias the or each rotary encoder to contact the or each respective tether or electrical cable.

[16] The lifting assembly comprises a wire connected to a gripping device, wherein the wire is configured to be wound up and / or unwound when the gripping assembly is raised and / or lowered, The system comprises a wire spool from which the wire is wound and / or unwound, wherein the wire is wound onto the wire spool such that the wire on the wire spool is short-circuited, Herein, the lifting assembly according to [1] is configured to measure the electrical resistance of the wire when the wire is wound up and / or unwound.

[17] The lifting assembly according to

[16] , further comprising a biasing assembly configured to resist the unwinding or winding of the wire spool so that the wire is tensioned between the lifting assembly and the gripping assembly.

[18] The lift assembly according to [1], comprising a time-of-flight, ToF, and sensor.

[19] The sensor comprises a light source and a photodetector, wherein, The light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly is raised and / or lowered. The lifting assembly according to [1], wherein the photodetector is configured to detect the reflection of the optical signal from the surface for detecting the movement of the surface.

[20] The lifting assembly according to

[19] , comprising an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to be retracted and / or untracted when the gripping mechanism is raised and / or lowered.

[21] The lifting assembly according to

[19] or

[20] , wherein the lifting assembly comprises wheels in contact with a tether spool from which the or each of the tethers is wound and / or unwound, or with an electrical cable spool from which an electrical cable is wound and / or unwound, wherein the wheels comprise the surface.

[22] The lifting assembly according to

[19] or

[20] , wherein the above or each tether spool or electrical cable spool comprises the surface.

[23] The lifting assembly according to any one of [1] to

[22] , wherein the controller is configured to use the determined vertical position to control / adjust the raising and / or lowering of the gripping assembly.

[24] The lifting assembly according to any one of [1] to

[23] , wherein the number of tethers is four, and optionally the tethers are comprising steel tape or polyester fabric tape.

[25] A cargo handling device for lifting and moving storage containers stacked in a grid framework structure, To form a grid pattern comprising multiple grid spaces, the device comprises a first set of parallel rails or tracks and a second set of parallel rails or tracks extending substantially perpendicular to the first set of rails or tracks in a substantially horizontal plane, wherein the grid is supported by a set of upright members to form multiple vertical storage positions directly below the grid, such that containers are stacked vertically between the upright members through the multiple grid spaces and guided by the upright members, and the cargo handling device is A body or frame attached to a first set of wheels arranged to engage with a first set of parallel tracks, and a second set of wheels arranged to engage with a second set of parallel tracks, A cargo handling device comprising a container lifting assembly having the lifting assembly described in any one of [1] to

[24] , wherein the gripping assembly comprises a container gripping assembly configured to grip a container.

[26] A method for determining the vertical position of the gripping assembly of the lifting assembly described in any one of paragraphs [1] to

[25] , the method being: The motor is used to raise and / or lower the gripping assembly, A method comprising using the output of the sensor to determine the vertical position of the gripping assembly using the controller.

[27] A computer program comprising instructions, wherein when the program is executed by a computer, the computer causes the computer to perform the method described in

[26] .

[28] A lifting assembly for raising a container from a stack of containers in a grid storage structure and / or lowering a container into a stack of containers, wherein the lifting assembly is A gripping assembly configured to grip a load, The gripping assembly comprises a lifting assembly configured to raise and lower the gripping assembly, and the lifting assembly is At least one tether connected to the gripping assembly, The lifting assembly further comprises a motor configured to wind up and / or unwind the tethers around at least one shaft in order to raise and / or lower the gripping assembly, wherein the lifting assembly further comprises A sensor configured to detect the movement of the gripping assembly, A lifting assembly comprising a controller configured to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the winding and / or unwinding of the tethers around the shafts for raising and / or lowering the gripping assembly.

[29] The lifting assembly according to

[28] , further comprising a second sensor, wherein the second sensor directly detects the rotation of the at least one shaft.

[30] The second sensor comprises a motor encoder for the motor, wherein the controller is The lifting assembly according to

[29] , configured to determine the failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the motor encoder.

[31] The lifting assembly according to

[30] , wherein the controller is configured to determine the fault of the grid assembly when the current output of the sensor does not correlate with the current output of the motor encoder by a threshold.

[32] Further comprising a tether spool for the or each tether, on which the or each tether is wound up and / or unwound, Herein, the second sensor comprises a tether rotary encoder for the or each tether spool, wherein the or each tether rotary encoder is configured to engage with the spool or each spool to detect the degree to which the or each spool has rotated when the or each tether is wound up and / or unwound. Herein, the controller, The lifting assembly according to

[29] , configured to determine the failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the or each tether rotary encoder.

[33] The lifting assembly according to

[32] , wherein the controller is configured to determine the failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the tether rotary encoder by a threshold.

[34] The lifting assembly is configured to include an electrical cable connected to the gripping assembly, wherein the electrical cable is retracted and / or unwinded when the gripping assembly is raised and / or lowered. The system includes an electrical cable spool from which the electrical cable is wound and / or unwound, Herein, the second sensor comprises an electrical cable rotary encoder for the electrical cable spool, wherein the or each electrical cable rotary encoder is configured to engage with the electrical cable spool to detect the degree to which the electrical cable spool rotates when the electrical cable is wound up and / or unwound. Herein, the controller, The lifting assembly according to

[29] , configured to determine the failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the electrical cable rotary encoder.

[35] Further comprising a tether spool for the or each tether, from which the or each tether is wound and / or unwound, Herein, the second sensor is a tether spool sensor equipped with a light source, It is equipped with a photodetector, and herein, The light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly is raised and / or lowered. The photodetector is configured to detect the reflection of the optical signal from the surface for detecting the movement of the surface, Herein, the controller, The lifting assembly according to

[29] , configured to determine the failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the tether spool sensor.

[36] The lifting assembly comprises wheels that contact the tether spool from which the or each tether is wound and / or unwound, wherein the wheels comprises the surface or Herein, the lifting assembly according to

[35] , wherein the above or each tether spool comprises the surface.

[37] The lifting assembly is configured to include an electrical cable connected to the gripping assembly, wherein the electrical cable is retracted and / or untracted when the gripping assembly is raised and / or lowered. The electrical cable is wound onto and / or unwound from an electrical cable spool, wherein, The second sensor comprises an electrical cable spool sensor with a light source and a photodetector, wherein the light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly rises and / or descends. The photodetector is configured to detect the reflection of the optical signal from the surface for detecting the movement of the surface, Herein, the controller, The lifting assembly according to

[29] , configured to determine the failure of the gripping assembly if the current output of the sensor does not correlate with the current output of the electrical cable spool sensor.

[38] The lifting assembly comprises wheels that contact an electrical cable spool from which the electrical cable is wound and / or unwound, Herein, the wheel has a surface, or Herein, the electrical cable spool comprises the lifting assembly according to

[37] , which has the surface.

[39] The sensor has an input that is engaged by the movement of the gripping assembly, wherein the controller, Receives a motion profile that controls the upward and / or downward movement of the gripper assembly. The vertical position of the gripping assembly is determined using the output of the sensor. The configuration is configured to determine the failure of the gripping assembly if the vertical position of the gripping assembly at the current time does not correlate with the corresponding vertical position derived from the motion profile by a threshold. A lifting assembly as described in any one of paragraphs

[28] through

[38] .

[40] The lifting assembly is configured to include an electrical cable connected to the gripping assembly, wherein the electrical cable is retracted and / or unwinded when the gripping assembly is raised and / or lowered, Herein, the sensor is configured to detect the extent to which the electrical cable is wound up and / or unwound. A lifting assembly according to any one of

[28] to

[39] , further comprising a biasing assembly configured to resist the unwinding or winding of an electrical cable spool so that the electrical cable is tensioned between the lifting assembly and the gripping assembly.

[41] The lifting assembly according to

[40] , further comprising an electrical cable spool from which the electrical cable is wound and / or unwound, wherein the sensor comprises a rotary encoder configured to engage with the electrical cable spool to detect the degree to which the electrical cable spool has rotated when the electrical cable is wound and / or unwound, wherein the electrical cable spool is configured to rotate with respect to the or each shaft.

[42] The lifting assembly according to

[40] or

[41] , wherein the electrical cable has a higher modulus of elasticity than the above or each tether.

[43] The lifting assembly according to any one of

[40] to

[42] , wherein the electrical cable transmits an electrical signal to the gripping assembly.

[44] The lifting assembly according to any one of the paragraphs

[39] to

[43] , comprising an electrical cable, flat flexible cable, FFC, or ribbon cable.

[45] The lifting assembly according to any one of

[28] to

[39] , wherein the sensor comprises a rotary encoder for the or each tether, wherein the rotary encoder is configured to contact each tether such that the winding and / or unwinding of the or each each tether rotates the input of the rotary encoder.

[46] The lifting assembly comprises an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to be retracted and / or untracted when the gripping mechanism is raised and / or lowered, wherein the electrical cable optionally comprises a flat flexible cable, an FFC, or a ribbon cable. Herein, the lifting assembly according to any one of

[28] to

[39] , wherein the sensor comprises a rotary encoder, wherein the rotary encoder is configured to engage with the electrical cable such that the winding and / or unwinding of the or each tether rotates the shaft of the rotary encoder.

[47] The lifting assembly according to

[45] or

[46] , further comprising a biasing assembly configured to bias the or each rotary encoder to contact the or each respective tether or electrical cable.

[48] ​​The lifting assembly is The lifting assembly includes an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to be retracted and / or untracted when the gripping mechanism is raised and / or lowered. An electrical cable spool from which the electrical cable is wound and / or unwound, wherein the electrical cable spool is configured to rotate with respect to the or each shaft, The system includes a biasing assembly configured to resist the unwinding or winding of the electrical cable spool, such that the electrical cable is tensioned between the lifting assembly and the gripping assembly, Herein, the sensor comprises an electrical cable spool sensor equipped with a light source and a photodetector, Herein, the light source is configured to transmit an optical signal onto a surface that moves as the gripping assembly is raised and / or lowered. The photodetector is configured to detect the reflection of the optical signal from the surface for detecting the movement of the surface, Herein, the lifting assembly optionally comprises a wheel that contacts the electrical cable spool from which the or each of the tethers is wound and / or unwound, wherein the wheel comprises the surface, or optionally, herein, the electrical cable spool comprises the surface, the lifting assembly according to any one of

[28] to

[39] .

[49] The lifting assembly comprises a wire connected to a gripping device, wherein the wire is configured to be wound up and / or unwound when the gripping assembly is raised and / or lowered, A wire spool from which the wire is wound and / or unwound, wherein the wire is wound onto the wire spool such that the wire on the wire spool is short-circuited, and wherein the wire spool is configured to rotate with respect to the or each shaft, The system includes a biasing assembly configured to resist the unwinding or winding of the wire spool so that the wire is tensioned between the lifting assembly and the gripping assembly, Herein, the lifting assembly according to any one of

[28] to

[39] , wherein the sensor is configured to measure the electrical resistance of the wire when the wire is wound up and / or unwound.

[50] The lifting assembly according to any one of

[28] to

[49] , comprising a time-of-flight, ToF, and sensor.

[51] The lifting assembly according to any one of

[28] to

[50] , wherein the controller is configured to stop the motor when it determines that the gripping assembly is in a fault.

[52] The lifting assembly according to any one of

[28] to

[51] , wherein the number of tethers is four, and optionally the tethers are comprising steel tape or polyester fabric tape.

[53] A cargo handling device for lifting and moving storage containers stacked in a grid framework structure, To form a grid pattern comprising multiple grid spaces, the device comprises a first set of parallel rails or tracks and a second set of parallel rails or tracks extending substantially perpendicular to the first set of rails or tracks in a substantially horizontal plane, wherein the grid is supported by a set of upright members to form multiple vertical storage positions directly below the grid, such that containers are stacked vertically between the upright members through the multiple grid spaces and guided by the upright members, and the cargo handling device is A body or frame attached to a first set of wheels arranged to engage with a first set of parallel tracks, and a second set of wheels arranged to engage with a second set of parallel tracks, A cargo handling device comprising a container lifting assembly having the lifting assembly described in any one of paragraphs

[28] to

[52] , wherein the gripping assembly comprises a container gripping assembly configured to grip a container. A method for determining an obstruction of a load assembly to a gripping assembly as described in any one of paragraphs

[54]

[28] to

[53] , the method being: The motor is used to raise and / or lower the gripping assembly, A method comprising using the controller to determine a failure of the gripping assembly if the current output of the sensor does not correlate with the winding and / or unwinding of the tethers around the shafts for raising and / or lowering the gripping assembly.

[55] A computer program comprising instructions, which, when the program is executed by a computer, causes the computer to perform the method described in

[54] .

Claims

1. A lifting assembly for raising a container from a stack of containers in a grid storage structure and / or lowering a container into a stack of containers, wherein the lifting assembly is A gripping assembly configured to grip a load, The gripping assembly comprises a lifting assembly configured to raise and lower the gripping assembly, and the lifting assembly is At least one tether connected to the gripping assembly, The lifting assembly further comprises a motor for winding up and / or unwinding the tether or each tether in order to raise and / or lower the gripping assembly, wherein the lifting assembly further comprises A sensor configured to detect the movement of the gripping assembly, wherein the sensor has an input that varies with the movement of the gripping assembly. A controller configured to determine the vertical position of the gripping assembly using the output of the sensor, The gripping assembly is further comprising an electrical cable connected to the gripping assembly, wherein the electrical cable is configured to be retracted and / or untracted when the gripping assembly is raised and / or lowered. Herein, the sensor is configured to detect the degree to which the electrical cable is wound up and / or unwound in a lifting assembly.

2. The lifting assembly according to claim 1, further comprising an electrical cable spool from which the electrical cable is wound and / or unwound, wherein the sensor comprises a rotary encoder configured to engage with the electrical cable spool to detect the degree to which the electrical cable spool has rotated when the electrical cable is wound and / or unwound.

3. The lifting assembly according to claim 1 or 2, wherein the electrical cable has a higher modulus of elasticity than the or each tether.

4. The lifting assembly according to claim 1 or 2, further comprising a tether spool for the or each tether from which the or each tether is wound, wherein the electrical cable spool and the or each tether spool are mounted on a shaft such that the electrical cable spool rotates relative to the or each tether spool.

5. The lifting assembly according to claim 1 or 2, further comprising a biasing assembly configured to resist the unwinding or winding of the electrical cable spool so that the electrical cable is tensioned between the lifting assembly and the gripping assembly.

6. The lifting assembly according to claim 1 or 2, wherein the electrical cable transmits an electrical signal to the gripping assembly.

7. The lifting assembly according to claim 1 or 2, wherein the electrical cable comprises a fixed flexible cable, an FFC, or a ribbon cable.

8. The lifting assembly according to claim 1 or 2, wherein the controller is configured to use the determined vertical position to control / adjust the raising and / or lowering of the gripping assembly.

9. The lifting assembly according to claim 1 or 2, wherein the number of tethers is four, and optionally, the tethers comprise steel tape or polyester fabric tape.

10. A cargo handling device for lifting and moving storage containers stacked in a grid framework structure, To form a grid pattern comprising multiple grid spaces, the device comprises a first set of parallel rails or tracks and a second set of parallel rails or tracks extending substantially perpendicular to the first set of rails or tracks in a substantially horizontal plane, wherein the grid is supported by a set of upright members to form multiple vertical storage positions directly below the grid, such that containers are stacked vertically between the upright members through the multiple grid spaces and guided by the upright members, and the cargo handling device is A body or frame attached to a first set of wheels arranged to engage with a first set of parallel tracks, and a second set of wheels arranged to engage with a second set of parallel tracks, A cargo handling device comprising a container lifting assembly having the lifting assembly according to claim 1 or 2, wherein the gripping assembly comprises a container gripping assembly configured to grip a container.

11. A method for determining the vertical position of the gripping assembly of the lifting assembly according to claim 1 or 2, wherein the method is: The motor is used to raise and / or lower the gripping assembly, A method comprising using the output of the sensor to determine the vertical position of the gripping assembly using the controller.

12. A computer program comprising instructions, wherein when the program is executed by a computer, the computer causes the computer to perform the method according to claim 11.

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