Patent Description:
This application claims priority from UK Patent Application no.

Some commercial and industrial activities require systems that enable the storage and retrieval of a large number of different products. One known type of system for the storage and retrieval of items in multiple product lines involves arranging storage bins or containers in stacks on top of one another, the stacks being arranged in rows. The storage bins or containers are accessed from above, removing the need for aisles between the rows and allowing more containers to be stored in a given space.

Methods of handling containers stacked in rows have been well known for decades. In some such systems, for example as described in <CIT> comprise freestanding stacks of containers arranged in rows in order to reduce the storage volume associated with storing such containers but yet still providing access to a specific container if required. Access to a given container is made possible by providing relatively complicated hoisting mechanisms which can be used to stack and remove given containers from stacks. The cost of such systems are, however, impractical in many situations and they have mainly been commercialised for the storage and handling of large shipping containers.

The concept of using freestanding stacks of containers and providing a mechanism to retrieve and store specific containers has been developed further, for example as described in <CIT>. '<NUM> discloses a mechanism for removing a plurality of stacked containers, using a robotic load handler in the form of a rectangular tube which is lowered around the stack of containers, and which is configured to be able to grip a container at any level in the stack. In this way, several containers can be lifted at once from a stack. The movable tube can be used to move several containers from the top of one stack to the top of another stack, or to move containers from a stack to an external location and vice versa. Such systems can be particularly useful where all of the containers in a single stack contain the same product (known as a single-product stack).

In the system described in '<NUM>, the height of the tube has to be as least as high as the height of the largest stack of containers, so that that the highest stack of containers can be extracted in a single operation. Accordingly, when used in an enclosed space such as a warehouse, the maximum height of the stacks is restricted by the need to accommodate the tube of the load handler.

<CIT>) describes a system in which stacks of containers are arranged within a frame structure. A system of this type is illustrated schematically in <FIG> of the accompanying drawings. Robotic load handling devices can be controllably moved around the stack on a system of tracks on the upper most surface of the stack.

One form of robotic load handling device is further described in<CIT>. <FIG> are schematic perspective views of a load handling device from the rear and front, respectively, and <FIG> is a schematic front perspective view of a load handling device lifting a bin.

A further development of load handling device is described in <CIT> where each robotic load handler only covers one grid space, thus allowing higher density of load handlers and thus higher throughput of a given size system.

<CIT> discloses a storage system suitable for storing multiple product lines in an automated warehouse environment. The storage system comprises a top level of a frame structure having the features in the preamble of claim <NUM>.

In some implementations of such bin handling systems, there can be a very large number of robotic load handling devices running on a single grid. These load handling devices can experience problems from time to time and require repair or other intervention in order to return to useful service. Furthermore, there may be spillages or a build-up of dirt or dust on the grid which will require cleaning.

It is a disadvantage of the prior art systems described above that in order to rescue a faulty load handling device or in order to clean the grid, a user is required to access the grid on the stack and perform the necessary operations manually to fix or remove the load handling device or to clean the grid.

For these operations to happen safely it is necessary to stop all robotic load handlers on the grid before the user is allowed access. The higher the number of robotic load handlers in use and the larger the grid, the higher the likelihood of faults occurring and an increased consequence of each fault, due to the number of units which have to be stopped.

According to the invention there is provided a top level of a frame structure according to claim <NUM>.

The invention will now be described with reference to the accompanying diagrammatic drawings in which.

As shown in <FIG> and <FIG>, stackable containers, known as bins <NUM>, are stacked on top of one another to form stacks <NUM>. The stacks <NUM> are arranged in a grid frame structure <NUM> in a warehousing or manufacturing environment. <FIG> is a schematic perspective view of the frame structure <NUM>, and <FIG> is a top-down view showing a single stack <NUM> of bins <NUM> arranged within the frame structure <NUM>. Each bin <NUM> typically holds a plurality of product items (not shown), and the product items within a bin <NUM> may be identical, or may be of different product types depending on the application.

The frame structure <NUM> comprises a plurality of upright members <NUM> that support horizontal members <NUM>, <NUM>. A first set of parallel horizontal members <NUM> is arranged perpendicularly to a second set of parallel horizontal members <NUM> to form a plurality of horizontal grid structures supported by the upright members <NUM>. The members <NUM>, <NUM>, <NUM> are typically manufactured from metal. The bins <NUM> are stacked between the members <NUM>, <NUM>, <NUM> of the frame structure <NUM>, so that the frame structure <NUM> guards against horizontal movement of the stacks <NUM> of bins <NUM>, and guides vertical movement of the bins <NUM>.

The top level of the frame structure <NUM> includes rails <NUM> arranged in a grid pattern across the top of the stacks <NUM>. Referring additionally to <FIG> and <FIG>, the rails <NUM> support a plurality of robotic load handling devices <NUM>. A first set 22a of parallel rails <NUM> guide movement of the load handling devices <NUM> in a first direction (X) across the top of the frame structure <NUM>, and a second set 22b of parallel rails <NUM>, arranged perpendicular to the first set 22a, guide movement of the load handling devices <NUM> in a second direction (Y), perpendicular to the first direction. In this way, the rails <NUM> allow movement of the load handling devices <NUM> in two dimensions in the X-Y plane, so that a load handling device <NUM> can be moved into position above any of the stacks <NUM>.

Each load handling device <NUM> comprises a vehicle <NUM> which is arranged to travel in the X and Y directions on the rails <NUM> of the frame structure <NUM>, above the stacks <NUM>. A first set of wheels <NUM>, consisting of a pair of wheels <NUM> on the front of the vehicle <NUM> and a pair of wheels <NUM> on the back of the vehicle <NUM>, are arranged to engage with two adjacent rails of the first set 22a of rails <NUM>. Similarly, a second set of wheels <NUM>, consisting of a pair of wheels <NUM> on each side of the vehicle <NUM>, are arranged to engage with two adjacent rails of the second set 22b of rails <NUM>. Each set of wheels <NUM>, <NUM> can be lifted and lowered, so that either the first set of wheels <NUM> or the second set of wheels <NUM> is engaged with the respective set of rails 22a, 22b at any one time.

When the first set of wheels <NUM> is engaged with the first set of rails 22a and the second set of wheels <NUM> are lifted clear from the rails <NUM>, the wheels <NUM> can be driven, by way of a drive mechanism (not shown) housed in the vehicle <NUM>, to move the load handling device <NUM> in the X direction. To move the load handling device <NUM> in the Y direction, the first set of wheels <NUM> are lifted clear of the rails <NUM>, and the second set of wheels <NUM> are lowered into engagement with the second set of rails 22a. The drive mechanism can then be used to drive the second set of wheels <NUM> to achieve movement in the Y direction.

In this way, one or more robotic load handling devices <NUM> can move around the top surface of the stacks <NUM> on the frame structure <NUM> under the control of a central picking system (not shown). Each robotic load handling device <NUM> is provided with means for lifting out one or more bins or containers from the stack to access the required products. In this way, multiple products can be accessed from multiple locations in the grid and stacks at any one time.

<FIG> shows a typical storage system as described above, the system having a plurality of load handling devices <NUM> active on the stacks <NUM>. In addition, a robotic service device <NUM> is positioned on the grid <NUM>.

It will be appreciated that any form of load handling <NUM> device may be in use and that the robotic service device may be suitably adapted to interact with any such load handling device <NUM>.

A first form of a second type of robotic service device <NUM>, will now be described with reference to <FIG>.

Referring to <FIG>, the robotic service device <NUM> comprises a vehicle <NUM> having first and second sets of wheels <NUM>, <NUM> that are engageable with the first and second sets 22a, 22b of rails <NUM>, respectively.

The robotic service device <NUM> is provided with features additional to those of the robotic load handling device <NUM>. As can be seen in <FIG> and <FIG>, the device <NUM> is provided with a releasable latching mechanism <NUM> and camera means <NUM>. Furthermore, the device <NUM> is provided with cleaning means such as brush mechanisms <NUM> and a vacuum cleaning system <NUM> mounted adjacent each set of wheels <NUM>, <NUM>. Moreover, the device <NUM> includes a spray device <NUM> capable of discharging suitable detergent under the control of the central picking system (not shown).

In a similar manner to the operation of the load handling device <NUM>, the first and second sets of wheels <NUM>, <NUM> of the robotic service device <NUM> can be moved vertically with respect to the vehicle <NUM> to engage or disengage the wheels <NUM>, <NUM> from the corresponding set of rails 22a, 22b. By engaging and driving the appropriate set of wheels <NUM>, <NUM>, the robotic service device <NUM> can be moved in the X and Y directions in the horizontal plane on the top of the frame structure <NUM>.

In the event of a failure or malfunction of a robotic load handling device 30a, the robotic service device <NUM> is moved on the grid <NUM> to a location adjacent the malfunctioning device 30a. Once adjacent to the malfunctioning device 30a, the camera means <NUM> of the service device <NUM> may be used to view the situation from a control position (not shown). If the load handling device 30a requires removal from the grid <NUM>, then the service device <NUM> may be releasably latched to the malfunctioning load handling device 30a as shown in <FIG>. The service device <NUM> may then be used to manipulate the malfunctioning device 30a to a location where it can be serviced or removed entirely from the grid <NUM>.

It will be appreciated that the form of the releasable latching mechanism <NUM> need not be as shown in <FIG> but that any suitable form of releasable latching mechanism may be used. The latching mechanism <NUM> may connect to a faulty robotic load handler and either lift it clear off the grid, or be able to raise and lower the sets of wheels on the faulty device, so as to be able to push, pull or drag it to a desired location. The latching mechanism <NUM> may also include a device for causing the faulty unit's gripper mechanism to be retracted from the grid or make any other mechanical or electrical intervention with the robotic load handler <NUM>.

Furthermore, it will be appreciated that the service device <NUM> may be provided with sensor means instead of or in addition to camera means <NUM>. For example, the service device <NUM> may be provided with sensors that allow a system operator to remotely diagnose a fault with a faulty or stationary robotic load handler <NUM>. This may include, but not be limited to, electrical connection means to connect to a port of the robotic load handler <NUM> to check for or diagnose faults via an installed diagnostic system. This may further include sensors such as ultrasonic detectors, x-ray cameras, or sensors for assessing the telecommunications functions within the load handling device <NUM>.

Moreover, the service device <NUM> may comprise reset means, in addition to or instead of the sensors discussed above, to enable the service device <NUM> to reset the robotic load handling device <NUM>. The reset means may comprise mechanical means such as a remotely operated manipulator device or it may comprise remotely operable electrical reset means. The mechanical manipulator may further be remotely operable to push the load handling device <NUM> should the diagnosis suggest the load handling device <NUM> is simply temporarily stuck on a portion of the grid. Alternatively, the mechanical device may act in conjunction with the service device <NUM> to push the load handling device to an alternative portion of the grid or off the grid completely.

In another use of the robotic service device <NUM>, the device <NUM> is used to travel over the grid <NUM> to establish the condition of the grid <NUM>. For example, over time spillages and dirt may build up on the grid <NUM>. The service device <NUM> may be provided with a traction measurement system whereby, for example, one or more wheels <NUM> are driven whilst one or more wheels <NUM> are braked, in order to establish if there is a spillage and hence loss of traction for the robotic load handlers <NUM> on the grid <NUM>. The service device <NUM> may then be deployed on the grid <NUM> and the camera means <NUM> used to remotely view the condition of the grid <NUM>. The brush mechanisms <NUM>, the spray detergent, <NUM> and the vacuum system <NUM> may then be used as appropriate to clean the grid <NUM>.

Spillage of products such as oil onto the grid, which makes the grid slippery, may be detected by ordinary robotic load handlers using slip detection on the wheels. It is then important to deal with the issue immediately to prevent oil to be spread over large portions of the grid. The proposed method would use several aspects of the robotic service <NUM> to deal with the issue. In use, any robotic device experiencing slippage would be stopped. Other robotic devices within a predetermined radius of the potential spillage would also be stopped. The picking control system may be used to block all potentially affected areas of the grid in software such that no other robotic devices <NUM>, <NUM> may access the affected area. One or more robotic service devices may then be deployed initially to clean the area around the now stationary robotic devices. The drive mechanism of the deployed service device <NUM> may then be used to measure traction, to ensure any spillage is properly removed. The robotic service device <NUM> may then be used to pick up and remove the affected robotic load handling device <NUM> to a maintenance area, such that the wheels may be cleaned. Further robotic service devices may be deployed to finish cleaning the affected area until there is sufficient traction on all parts of the grid.

Furthermore, the robotic service device <NUM> may be provided with means for assessing the mechanical condition of the tracks and the grid. For example, the service device <NUM> may use sensor or camera means described above to assess the condition of the grid in addition to or separably from assessing the condition of robotic load handling devices <NUM>.

For example, the robotic service device may be deployed on to the grid during a housekeeping phase to ensure the stability and integrity of the tracks and grid.

It will be appreciated that the service device <NUM> may comprise all, one or any combination of the features described above and that it is not essential to the invention for the service device to include all the sensors and features described. <FIG> and <FIG> show an embodiment of the invention. Features similar to that described with reference to examples of robotic devices described earlier will be referenced with the same reference numbers.

<FIG> shows an alternative form of robotic service device <NUM>. The robotic service device <NUM> comprises a substantially bridge shaped vehicle <NUM>. Referring to <FIG> and <FIG>, the robotic service device <NUM> comprises a vehicle <NUM> having first and second sets of wheels <NUM>, <NUM> that are engageable with the first and second sets 22a, 22b of rails <NUM>, respectively. The bridge-shaped vehicle <NUM> is sized so as to be capable of straddling a load handling device <NUM>. The service device <NUM> is provided with a releasable latching or hook mechanism <NUM> deployable from the underside of the bridge portion.

In use, the first and second sets of wheels <NUM>, <NUM> of the robotic service device <NUM> can be moved vertically with respect to the vehicle <NUM> to engage or disengage the wheels <NUM>, <NUM> from the corresponding set of rails 22a, 22b. By engaging and driving the appropriate set of wheels <NUM>, <NUM>, the robotic service device <NUM> can be moved in the X and Y directions in the horizontal plane on the top of the frame structure <NUM>.

In this manner, the service device <NUM> may be deployed on the grid <NUM> and driven to a point whereby it straddles a malfunctioning load handling device <NUM> such that the latching or hook mechanism <NUM> may be used to lift the malfunctioning device <NUM> from the grid <NUM>. The picking control system may then be used to move the service device <NUM> to a position on the grid <NUM> where the malfunctioning load handling device <NUM> may be removed as necessary. It will be appreciated that, although not shown in the drawings, the service device in the second embodiment may also have the features described with reference to the first embodiment, including but not limited to brush mechanisms <NUM>, vacuum systems <NUM>, spray systems <NUM>, traction measurement systems and camera means <NUM>, all operational in a similar manner to that described above.

<FIG> shows the embodiment of the invention. Features similar to that described with reference to examples of robotic devices described earlier will be referenced with the same reference numbers.

Referring to <FIG>, the robotic service device <NUM> comprises a vehicle <NUM> having first and second sets of wheels <NUM>, <NUM> that are engageable with the first and second sets 22a, 22b of rails <NUM>, of the grid <NUM> respectively. The u-shaped vehicle <NUM> is sized so as to be capable of enclosing a load handling device <NUM>. The service device <NUM> is provided with a releasable latching or hook mechanism <NUM> deployable from within the u-shaped portion.

In use, the first and second sets of wheels <NUM>, <NUM> of the robotic service device <NUM> can be moved vertically with respect to the vehicle <NUM> to engage or disengage the wheels <NUM>, <NUM> from the corresponding set of rails 22a, 22b. By engaging and driving the appropriate set of wheels <NUM>, <NUM>, the robotic service device <NUM> can be moved in the X and Y directions in the horizontal plane on the top of the grid <NUM>.

In this manner, the service device <NUM> may be deployed on the grid <NUM> and driven to a point whereby it encloses a malfunctioning load handling device <NUM> such that the latching or hook mechanism <NUM> may be used to pull, push or otherwise manipulate the malfunctioning device <NUM>. The picking control system may then be used to move the service device <NUM> to a position on the grid <NUM> where the malfunctioning load handling device <NUM> may be removed as necessary. It will be appreciated that, although not shown in the drawings, the service device may also have the features described with reference to examples of robotic devices described earlier, including but not limited to brush mechanisms <NUM>, vacuum systems <NUM>, spray systems <NUM>, traction measurement systems and camera means <NUM>, all operational in a similar manner to that described above.

It will be appreciated that the latching device need not take the form of a hook but that any suitable latching means may be used. For example the latching means may be magnetic or electro-magnetic. Furthermore, the latching means may be positioned at any point on the service device, indeed a plurality of latching mechanisms may be employed on all sides of the service device such that a load handling device may be approached and latched from any direction on the grid.

Moreover, the latching mechanism of the service device may interact with the load handling device in any way suitable to remove the load handling device from the grid. There may be electronic communication or mechanical interaction between the service device and the load handling device of any form in order to release the load handling device from the grid.

<FIG> show a further example of a robotic service device <NUM>. Features similar to that described earlier will be referenced with the same numerals.

In <FIG>, a pair of robotic service devices <NUM> are shown connected by a suitable member <NUM>. The member <NUM> allows the separate robotic service devices <NUM> to act as a single unit. The member <NUM> is further provided with connecting, latching and lifting means <NUM>, <NUM>.

The connected robotic service devices <NUM> are remotely manoeuvred into position such that they occupy grid spaces adjacent an inoperable load handling device <NUM>. From this position the latching means <NUM> can be lowered or adjusted to connect with a co-operating latching point <NUM> on the robotic load handling device <NUM>. Once connected, the lifting means <NUM> is operated to lift the inoperable load handling device <NUM> clear of the grid and tracks. Once lifted clear, the connected robotic service devices <NUM> can be remotely instructed to move to a position off the grid to enable recovery of the robotic load handling device.

<FIG> and <FIG> show alternative configurations for the connected robotic service devices <NUM> and alternative positions of the member <NUM> and the connecting latching and lifting means <NUM>, <NUM>.

It will be appreciated that in this example, it is possible to approach and lift robotic load handling devices from any part of the grid, including the very corners or edges or adjacent supporting structures as the robotic service device <NUM> connects to the load handling device <NUM> at a top mounted coupling.

It will be appreciated that the configurations shown in <FIG> are just a selection of a number of possible configurations and that the example is not limited to simply these configurations. The connecting, latching and lifting mechanism may be a single mechanism or three separate mechanisms. The connecting and latching mechanisms may comprise mechanical, magnetic or electro-magnetic means or any other suitable means. The lifting means may comprise winch means <NUM> or any other suitable lifting means.

<FIG> shows another example. Features similar to that described with reference to the previous examples of the invention will be referenced with the same reference numbers.

Referring to <FIG>, the service device <NUM> comprises a substantially planar vehicle <NUM> having first and second sets of wheels <NUM>, <NUM> that are engageable with the first and second sets 22a, 22b of rails <NUM>, of the grid <NUM> respectively. The planar vehicle <NUM> is provided with seating means <NUM> so as to be capable of carrying a user. The service device <NUM> may be robotically controlled by the picking system control but may also be manually driven by the user (not shown).

In use, the first and second sets of wheels <NUM>, <NUM> of the service device <NUM> can be moved vertically with respect to the vehicle <NUM> to engage or disengage the wheels <NUM>, <NUM> from the corresponding set of rails 22a, 22b. By engaging and driving the appropriate set of wheels <NUM>, <NUM>, the service device <NUM> can be moved in the X and Y directions in the horizontal plane on the top of the grid <NUM>.

In this manner, the service device <NUM> may be deployed on the grid <NUM> and driven to a predetermined point on the grid where inspection or maintenance is required.

It will be appreciated that, although not shown in the drawings, the service device <NUM> of the fifth example may also have the features described with reference to the service device in the previous examples, including but not limited to brush mechanisms <NUM>, vacuum systems <NUM>, spray systems <NUM>, traction measurement systems and camera means <NUM>, all operational in a similar manner to that described above.

In this manner, the integrity of a large robotically controlled picking system can be maintained and cleaned without the requirement of stopping the whole system to retrieve malfunctioning load handling devices or to clean spillages on the grid. In systems of significant size this can represent a substantial decrease in the down time of the system.

Furthermore, it is possible for the robotic service device described in all or any of the embodiments above to be adapted to carry equipment such as barriers (not shown). The remotely operable mechanical manipulating means may position barriers around a portion of the grid for example, for safety reasons should an operator need to be present on the grid.

It will be appreciated that robotic service devices as described above may contain one or all of the features described. For example, a service device may be capable of lifting a malfunctioning load handling device off the grid and removing it to a maintenance location on the grid, whilst also comprising traction monitoring means and cleaning devices. Furthermore, a ride-on service device may also be provided with the means to pull a malfunctioning load handling device off the grid.

Furthermore, the robotic service device <NUM> may comprise a load carrying portion, similar to the load handling device, the load carrying portion being adapted to carry maintenance and cleaning equipment such as that described above. Moreover, the load carrying portion may be interchangeable such that one service device may be able to perform different functions depending on the load carrying portion provided at any one time.

It will also be appreciated that the robotic load handling devices <NUM> may be of the cantilever form shown in <FIG>, that occupy two grid spacings or alternatively the robotic load handling devices <NUM> may be of the form shown in <FIG> where they occupy only a single grid spacing.

Claim 1:
The top level of a frame structure (<NUM>) suitable for a warehousing or manufacturing environment for supporting robotic load handling devices, the top level comprising a first set of parallel rails (22a) extending in an X direction and a second set of parallel rails (22b) extending in a Y direction perpendicular to the X direction, the X and Y directions being in a horizontal plane on the top level of the frame structure;
wherein the first and second sets of rails (22a, 22b) form a uniform grid pattern across the top of the stacks comprising an array of openings, each opening being a rectangular opening and having a width in the X direction and a length in the Y direction,
wherein each rail in the second set of rails (22b) comprises a longitudinally extending dividing structure, centrally dividing the respective rail into two adjacent tracks, each track being engageable by a wheel of a robot service device (<NUM>),
characterised in that:
each opening is surrounded along its width and length, by a raised lip provided by the rails (22a, 22b);
wherein each rail in the first set of rails (22a) comprises a longitudinally extending dividing structure, centrally dividing the respective rail into two adjacent tracks, each track being engageable by a wheel of a robot service device (<NUM>),
and wherein the dividing structure of each rail of the first set of rails (22a) comprises a series of raised dividers, each raised divider extending along, and parallel to, the full width of an adjacent opening,
and wherein the dividing structure of each rail of the second set of rails (22b) comprises a series of raised dividers, each raised divider extending along, and parallel to, the full length of an adjacent opening;
and wherein each raised divider of the dividing structure of each rail of the first set of rails (22a) extends no further than the width of the respective adjacent opening, and each raised divider of the dividing structure of each rail of the second set of rails (22b) extends no further than the length of the respective adjacent opening.