Patent Description:
<FIG> and <FIG> disclose a typical prior art automated storage and retrieval system <NUM> with a framework structure <NUM>. <FIG> disclose a prior art container handling vehicle <NUM> operating the system <NUM> disclosed in <FIG> and <FIG>, respectively.

The framework structure <NUM> comprises a plurality of upright members <NUM> and optionally a plurality of horizontal members <NUM> supporting the upright members <NUM>.

The framework structure <NUM> defines a storage grid <NUM> comprising storage columns <NUM> arranged in rows, in which storage columns <NUM> storage containers <NUM>, also known as bins, are stacked one on top of another to form stacks <NUM>.

Each storage container <NUM> may typically hold a plurality of product items (not shown), and the product items within a storage container <NUM> may be identical, or may be of different product types depending on the application.

The storage grid <NUM> guards against horizontal movement of the containers <NUM> in the stacks <NUM>, and guides vertical movement of the containers <NUM>, but does normally not otherwise support the storage containers <NUM> when stacked.

The automated storage and retrieval system <NUM> comprises a rail system <NUM> arranged in a grid pattern across the top of the storage <NUM> along a horizontal plane P, on which rail system <NUM> a plurality of container handling vehicles <NUM>,<NUM> (as exemplified in <FIG> and <FIG>) are operated to raise storage containers <NUM> from, and lower storage containers <NUM> into, the storage columns <NUM>, and also to transport the storage containers <NUM> above the storage columns <NUM>. The horizontal extension of one of the grid cells <NUM> constituting the grid pattern is in <FIG> and <FIG> marked by thick lines.

Each grid cell <NUM> has a width which is typically within the interval of <NUM> to <NUM>, and a length which is typically within the interval of <NUM> to <NUM>. Each grid opening <NUM> has a width and a length which is typically <NUM> to <NUM> less than the width and the length of the grid cell <NUM> due to the horizontal extent of the rails <NUM>,<NUM>.

In this way, the rail system <NUM> defines grid columns above which the container handling vehicles <NUM>,<NUM> can move laterally above the storage columns <NUM>, i.e. in a plane which is parallel to the horizontal X-Y plane.

Each prior art container handling vehicle <NUM>,<NUM> comprises a vehicle body / framework and a wheel arrangement of eight wheels <NUM>,<NUM> where a first set of four wheels enable the lateral movement of the container handling vehicles <NUM>,<NUM> in the X direction and a second set of the remaining four wheels enable the lateral movement in the Y direction. One or both sets of wheels in the wheel arrangement can be lifted and lowered, so that the first set of wheels and/or the second set of wheels can be engaged with the respective set of rails <NUM>, <NUM> at any one time.

Each prior art container handling vehicle <NUM>,<NUM> also comprises a lifting device (not shown) for vertical transportation of storage containers <NUM>, e.g. raising a storage container <NUM> from, and lowering a storage container <NUM> into, a storage column <NUM>. The lifting device comprises one or more gripping / engaging devices (not shown) which are adapted to engage a storage container <NUM>, and which gripping / engaging devices can be lowered from the vehicle <NUM>,<NUM> so that the position of the gripping / engaging devices with respect to the vehicle <NUM>,<NUM> can be adjusted in a third direction Z which is orthogonal the first direction X and the second direction Y.

Conventionally, and also for the purpose of this application, Z=<NUM> identifies the uppermost layer of the grid <NUM>, i.e. the layer immediately below the rail system <NUM>, Z=<NUM> the second layer below the rail system <NUM>, Z=<NUM> the third layer etc. In the exemplary prior art grid <NUM> disclosed in <FIG> and <FIG>, Z=<NUM> identifies the lowermost, bottom layer of the grid <NUM>. Consequently, as an example, and using the Cartesian coordinate system X, Y, Z indicated in <FIG> and <FIG>, the storage container identified as <NUM>' in <FIG> can be said to occupy grid location or cell X=<NUM>, Y=<NUM>, Z=<NUM>. The container handling vehicles <NUM> can be said to travel in layer Z=<NUM> and each grid column can be identified by its X and Y coordinates.

Each container handling vehicle <NUM> comprises a storage compartment or space (not shown) for receiving and stowing a storage container <NUM> when transporting the storage container <NUM> across the rail system <NUM>. The storage space may comprise a cavity arranged centrally within the vehicle body, e.g. as is described in <CIT>.

Alternatively, the container handling vehicles <NUM> may have a cantilever construction, as is described in <CIT>.

The container handling vehicles <NUM> may have a footprint, i.e. an extent in the X and Y directions, which is generally equal to the lateral extent of a grid cell <NUM>, i.e. the extent of a grid cell <NUM> in the X and Y directions, e.g. as is described in <CIT>. The term "lateral" used herein may mean "horizontal".

Alternatively, the container handling vehicles <NUM> may have a footprint which is larger than the lateral area defined by a grid column, e.g. as is disclosed in <CIT>.

In a storage grid <NUM>, a majority of the grid columns are storage columns <NUM>, i.e. grid columns <NUM> where storage containers <NUM> are stored in stacks <NUM>. However, a grid <NUM> normally has at least one grid column which is used not for storing storage containers <NUM>, but which comprises a location where the container handling vehicles <NUM>,<NUM> can drop off and/or pick up storage containers <NUM> so that they can be transported to an access station (not shown) where the storage containers <NUM> can be accessed from outside of the grid <NUM> or transferred out of or into the grid <NUM>. Within the art, such a location is normally referred to as a "port" and the grid column in which the port is located may be referred to as a "port column" <NUM>,<NUM>.

The storage grids <NUM> in <FIG> and <FIG> comprise two port columns <NUM> and <NUM>. The first port column <NUM> may for example be a dedicated drop-off port column where the container handling vehicles <NUM>,<NUM> can drop off storage containers <NUM> to be transported to an access or a transfer station, and the second port column <NUM> may be a dedicated pick-up port column where the container handling vehicles <NUM>,<NUM> can pick up storage containers <NUM> that have been transported to the storage grid <NUM> from an access or a transfer station.

The access station may typically be a picking or a stocking station where product items are removed from or positioned into the storage containers <NUM>. In a picking or a stocking station, the storage containers <NUM> are normally never removed from the automated storage and retrieval system <NUM>, but are returned into the storage grid <NUM> once accessed. Alternative to ports as part of the storage grids <NUM>, it may be envisaged ports that transfer storage containers out of or into the storage grid <NUM>, e.g. for transferring storage containers <NUM> to another storage facility (e.g. to another storage grid), directly to a transport vehicle (e.g. a train or a lorry), or to a production facility.

For monitoring and controlling the automated storage and retrieval system <NUM> (e.g. monitoring and controlling the location of respective storage containers <NUM> within the storage grid <NUM>; the content of each storage container <NUM>; and the movement of the container handling vehicles <NUM>,<NUM> so that a desired storage container <NUM> can be delivered to the desired location at the desired time without the container handling vehicles <NUM>,<NUM> colliding with each other), the automated storage and retrieval system <NUM> comprises a control system (not shown) which typically is computerized and which typically comprises a database for keeping rail of the storage containers <NUM>.

A problem associated with known automated storage and retrieval systems <NUM> is that it is challenging for personnel to access the rail system <NUM> for carrying out inspection, or to carry out maintenance of or to remove malfunctioning container handling vehicles <NUM>,<NUM>.

<CIT>, which the EPO identified in the examination procedure as the 'closest prior art', discusses, according to its abstract, that "A robotic service device is described for use on a robotic picking system grid. The robotic service device is capable of driving to any location on the grid order to perform maintenance operations or cleaning. Additionally, the service device may be used to rescue robotic load handling devices operational in the picking system. The robotic service device may comprise a releasable docking mechanism to enable it to dock and latch on to malfunctioning load handling devices. The service device may also be provided with cleaning means and camera means to enable the condition of the grid and other robotic devices to be monitored. A service vehicle is arranged with a releasable latching mechanism for docking with a malfunctioning container handling vehicle. After connecting with the vehicle, the service vehicle brings the vehicle to a designated location on the grid for inspection and maintenance by pulling or pushing. This publication also suggests an overhead carrying arrangement for removing a malfunctioning vehicle from the grid. In this arrangement either a bridge-shaped robotic vehicle or two parallelly arranged robotic vehicles connected with a cross beam is/are arranged with a lift for elevating the load handling device from the grid. The malfunctioning vehicle is carried in this elevated position to the designated location. In addition, the publication suggests that the service vehicle may be arranged with a seat for carrying a user to inspect and carry out maintenance. This personnel carrying version of the service vehicle may be manually operated by the user, or alternatively remotely controlled by the control system. Accordingly, <CIT> is useful to understand the invention, i.e. the technical problem, its solution as well as advantageous effects conferred by the invention.

However, the known service vehicle is restricted to follow the underlying grid system, i.e. in the X and Y directions only. The service vehicle thus moves on the grid in the same way as that of load handling device, thus occupying a large amount of space during the service procedure due to the zigzag movement pattern both ways. The particular movement pattern also increases the time spent on the grid. In the case of automated storage and retrieval systems having a high density of container handling vehicles, such use of space and time may reduce significantly the overall efficiency. Further, the push or pull method may prove cumbersome and thereby add additional operational time of the service vehicle on the rail system.

In view of the above, it is desirable to provide a service vehicle, an automated storage and retrieval system using such a service vehicle, and a method thereof, that solve or at least mitigate one or more of the aforementioned problem related to use of prior art storage and retrieval systems.

The invention includes a service vehicle for movement on a rail system. The rail system may comprise a first set of parallel rails arranged in a horizontal plane P and extending in a first direction X, and a second set of parallel rails arranged in the horizontal plane P and extending in a second direction Y which is orthogonal to the first direction X, which first and second sets of rails form a grid pattern in the horizontal plane P comprising a plurality of adjacent grid cells.

The service vehicle comprises a vehicle body or framework and propulsion means or propulsion mechanism for allowing movement of the service vehicle over the top of the rail system during operation. The vehicle body / framework contains or support vehicle handling components / a container vehicle handling part for mechanical interacting with a container handling vehicle operating on the rail system and operational components / an operational part for controlling operations of the service vehicle other than the direct handling of the at least one container handling vehicle. The container vehicle handling part and the operational part may be separated fully or partly in space.

Propulsion means or propulsion mechanisms configured to run over the top of the rail system is caterpillar tracks.

Hereinafter the term 'over the top of the rail system' signifies that the propulsion means rest on the rail system, but do not engage with the rails themselves. Hence, the service vehicle is not restricted to movement only in the direction of the rails but can move in any direction over the top of the rail system.

The caterpillar tracks have an overall length L exceeding the distance across two grid cells in the first direction X and/or across two grid cells in the second direction Y when the service vehicle is moving on top of the rail system. In a more preferred configuration, the caterpillar tracks have an overall length L exceeding the distance across three grid cells in the first and/or the second direction X,Y, for example across <NUM> grid cells. These minimum lengths of the tracks ensure safe movement of the service vehicle on the rail system. In addition, the minimum lengths ensure that the tracks spreads the weight of the service vehicle across the top of several rails at any one time.

The overall length L may for example be <NUM> or more.

The term "overall length L" signifies herein the length from one extremity of the tracks along its longitudinal direction to the opposite extremity of the tracks along its longitudinal direction.

In order to further increase overall stability during operation on the rail system, and in particular directional stability, the tracks may further have an overall width W that exceeds the width of adjacent rails when the service vehicle is moving on the rail system, i.e. exceed the width of one grid cell.

The term "overall width W" signifies herein the width from one extremity of the tracks perpendicular to its longitudinal direction to the opposite extremity of the tracks perpendicular to its longitudinal direction, including any gap G therebetween.

The caterpillar tracks comprises a longitudinal extending endless belt of the length L and a belt motor driving the endless belt. The belt may be made of a flexible or resilient material such a material comprising rubber. In addition, the coupling of the tracks to the vehicle body may comprise a spring arrangement. The flexibility of the tracks ensures a stable operation with low risk of damaging the underlying rails.

Ina non-limiting embodiment, the tracks may comprise at least one wheel, preferably at least two wheels, contacting the first endless belt. Further, the belt motor may drive the endless belt via the at least one wheel or a separate wheel or a combination of both.

The at least one wheel may contact an inner surface of the endless belt, for example by a configuration where the endless belt is surrounding the at least one wheel. The rotational axis of the at least one wheel may be parallel to a rotational axis of the endless belt. The term 'inner surface of the endless belt' signifies herein the surface of the belt facing towards the volume of the belt confined by the belt's width W and length L.

The at least one wheel may act as a propulsion unit for the belts or as a tightening means for the belt or a combination thereof.

In case of at least track wheels it is advantageous to arrange wheels at each longitudinal ends of the track.

The first caterpillar track comprises a longitudinal extending endless belt and the second caterpillar track comprises a longitudinally extending endless belt directed parallel to the first caterpillar track, for example attached to opposite side walls of a vehicle body of the service vehicle. The first caterpillar track and the second caterpillar track may be spaced apart by a gap G measured along the direction of the rotational axis of the endless belts. The width of gap G is in this embodiment preferably at least the width of a grid cell of the rail system in either the first direction X or the second direction Y.

The first and/or second caterpillar tracks is/are preferably arranged such that endless belt(s) is/are at least partly extending beyond a vehicle body containing and/or supporting the container vehicle handling part and the operational part in the direction of the rotational axis to i. create physical barriers protecting the operator against collisions with objects located on the rail system.

In order to ensure sufficient stiffness of the belts, and thereby ensure that the service vehicle is moving satisfactory over the top of the rail system, each belt preferably comprise one or more struttings. A further desirable increase in overall stiffness of the tracks may be achieved by adding stabilization wheels contacting the belt or belts, for example on top of the belt(s) relative to the rail system.

Further, the tracks may advantageously be connected symmetrically in the horizontal plane (P) to the vehicle body. For example, the first and second caterpillar tracks may be arranged at the exterior side walls of the service vehicle's vehicle body symmetrically around a center axis of the vehicle body running perpendicular to the tracks' rotational axis.

The container vehicle handling part may include a transfer device configured to transfer at least one container handling vehicle between an operating position on the rail system, that is, a lower position where the container handling vehicle is movable on the rail system, and a transport position within the vehicle body during operation, i.e. an upper position where the container handling vehicle is lifted above the rail system. The container vehicle handling part may also include a transfer motor configured to power the transfer device, thereby allowing said transfer of the container handling vehicle.

The transfer device may be arranged at least partly between the first and second caterpillar tracks, for example fully within the container vehicle handling part and approximately centered within the gap G relative to the belts rotational axis.

In a first configuration of the service vehicle, the transfer device is configured to support the container handling vehicle from below, for example by applying a base plate onto which the container handling vehicle may be supported.

For this first configuration, the transfer device may be configured to move between an upper and a lower position relative to the horizontal plane P and may further be configured to allow the container handling vehicle to move from its operating position on the rail system to a transport position on the base plate when the transfer device is in its lower position.

The operational part comprises a propulsion means motor allowing movement of the service vehicle along the horizontal plane P. The operational part may further comprise an onboard operating system allowing an onboard operator to control and regulate both the direction and the speed of the service vehicle relative to the underlying rail system. The change in direction may cover a <NUM>° rotation of the service vehicle. Alternatively, said operating system may be remotely located, hence regulating the direction and the speed of the service vehicle by remote control.

A configuration of the service vehicle allowing vertical displacement of the operational part or the container vehicle handling part or both may also be envisaged. The control and regulation of the speed also includes start and full halt. The service vehicle may further comprise a registration unit such as an image capturing unit being configured to allow visual inspection of the surroundings of the service vehicle. The image capturing unit may for example comprise a forward camera and a rearward camera, either fixed or rotatable relative to the horizontal plane P.

The service vehicle is arranged for transporting at least one of the at least one container handling vehicle in the horizontal plane P and preferably also for transporting one or more people. Alternatively, the service vehicle may be remotely controlled.

The service vehicle may further comprise a transmitter and/or receiver for establishing signal communication with a remote control system.

The transfer device may comprise an attachment device for releasable attachment to the at least one container handling vehicle, a vertical linear actuator attached at one end at least indirectly to the vehicle body, for example via a pivot support, and the other end at least indirectly to the attachment device, wherein the vertical linear actuator is configured to displace the attachment device relative to the vehicle body in a vertical direction.

The transfer device may further comprise a horizontal linear actuator fixed to the vehicle body and which is configured to displace the attachment device relative to the vehicle body in a horizontal direction.

The automated storage and retrieval system includes a rail system comprising a first set of parallel rails arranged in a horizontal plane P and extending in a first direction X, and a second set of parallel rails arranged in the horizontal plane P and extending in a second direction Y which is orthogonal to the first direction X, which first and second sets of rails form a grid pattern in the horizontal plane P comprising a plurality of adjacent grid cells and a service vehicle as described above.

The system further comprises at least one container handling vehicle being configured to move on the rail system, wherein the at least one container handling vehicle comprises a wheel arrangement being configured to guide the at least one storage container vehicle along the rail system in at least one of the first direction X and the second direction Y.

The service vehicle may comprise a vehicle body / framework containing or supporting a container vehicle handling part for mechanical interaction with at least one of the at least one container handling vehicle operating on the rail system and an operational part for controlling operations of the service vehicle.

In a second aspect, the invention concerns a method for operating a service vehicle according to claim <NUM>.

In an alternative configuration, the vehicle body of the service vehicle of the system comprises a fence. The fence defines a loading area of the service vehicle configured for containing at least one storage container vehicle. The fence may further comprise an access ramp pivotally connected to the vehicle body for pivoting the access ramp between an inclined, lower position relative to the underlying rail system allowing the one or more storage container vehicle to be transported between the rail system and the loading area via the access ramp and a closing, upper position for closing off the loading area.

The loading area of the fence may also, or alternatively, be configured to accommodate one or more operators. In this configuration fence acts as a protective chamber for the personnel.

A protective barrier such as the protective chamber or rollers connected at the outer surface of the vehicle body is a clear advantage compared with the personnel carrying service vehicle disclosed in <CIT> where the open operational part of the service vehicle offers little or no protection for the operator, for example in case of a collision between the service vehicle and obstacles on the rail system such as the container handling vehicles.

In yet an alternative configuration the vehicle body is movably arranged relative to the first and second belted driving wheel assembly between.

In the drawings, the same reference numerals have been used to indicate like parts, elements or features unless otherwise explicitly stated or implicitly understood from the context.

With reference to <FIG> and <FIG> the storage grid <NUM> of each storage structure <NUM> constitutes a framework <NUM> of in total <NUM> grid cells, where the width and length of the framework corresponds to the width and length of <NUM> grid columns. The top layer of the framework <NUM> is a rail system <NUM> onto which a plurality of container handling vehicles <NUM>,<NUM> are operated.

The framework <NUM> of the automated storage and retrieval system <NUM> is constructed in accordance with the prior art framework <NUM> described above, i.e. a plurality of upright members <NUM> and a plurality of horizontal members <NUM> which are supported by the upright members <NUM>, and further that the horizontal members <NUM> includes the rail system <NUM> of parallel rails <NUM>,<NUM> in the X direction and the Y direction, respectively, arranged across the top of storage columns <NUM>. The horizontal area of a single grid cell, i.e. along the X and Y directions, may be defined by the distance between adjacent rails <NUM> and <NUM>, respectively (see also <FIG> and <FIG>). In <FIG> and <FIG>, such a grid cell <NUM> is marked on the rail system <NUM> by thick lines.

The rail system <NUM> allows the container handling vehicles <NUM>,<NUM> to move horizontally between different grid locations, where each grid location is associated with a grid cell <NUM>.

In <FIG> and <FIG> the storage grid <NUM> is shown with a height of eight cells. It is understood, however, that the storage grid <NUM> can in principle be of any size. In particular it is understood that storage grid <NUM> can be considerably wider and/or longer than disclosed in <FIG> and <FIG>. For example, the grid <NUM> may have a horizontal extension of more than 700x700 grid cells <NUM>. Also, the grid <NUM> can be considerably deeper than disclosed in <FIG> and <FIG>. For example, the storage grid <NUM> may be more than twelve grid cells deep.

The storage container vehicles <NUM>,<NUM> may be of any type known in the art, e.g. any one of the automated container handling vehicles disclosed in <CIT>, in <CIT> or in <CIT>.

<FIG> show a first embodiment of a service vehicle <NUM> of the system <NUM> arranged on the rail system <NUM>. The service vehicle <NUM> comprises a vehicle body <NUM> and two caterpillar tracks <NUM>,<NUM>, each comprising an endless belt 6d with length L and arranged at least partly below the vehicle body <NUM>. Each of the tracks <NUM>,<NUM> is driven by aid of a belt motor and a belt wheel 6a,6b arranged within the belts 6d at both belt ends, i.e. at the tracks' front and rear A common belt motor is used for both belts 6d.

The first and second tracks <NUM>,<NUM> are arranged symmetrically around a vertical centerplane of the service vehicle <NUM> in its direction of movement and are protruding at least partly from the horizontal extremity of the vehicle body <NUM>. The service vehicle <NUM> may be divided into two functional parts, a container vehicle handling part <NUM> including the components responsible for any mechanical interaction with the container handling vehicle <NUM>,<NUM> to be serviced and an operational part <NUM> including any components responsible for the operation of the service vehicle <NUM>. In this particular embodiment the two parts are separated in space relative to the horizontal extent of the service vehicle <NUM>.

Each of the first and second tracks <NUM>,<NUM> comprises in the example shown in <FIG> a looped chain 6d and two toothed belt wheels 6a,6b arranged inside the chain 6d at each of the tracks <NUM>,<NUM> longitudinal ends. The first toothed belt wheel 6a are arranged at the terminal end (front and rear) of the chains 6d and has a diameter sufficiently large to mesh with both the lower and upper parts of the chain 6d. The second toothed belt wheel 6b has in the example a smaller diameter than the first toothed belt wheel 6a and is arranged to mesh with the lower parts of the chains 6d at a location further towards the longitudinal center of the tracks <NUM>,<NUM>.

Note that the terms "upper" and "lower" are measured relative to the underlying rail system <NUM>.

The looped chains 6d constituting the two tracks <NUM>,<NUM>, i.e. one chain 6d for each track <NUM>,<NUM>, are preferably made of a resilient material capable of not inflicting damages when moving in contact with top surfaces of the rails <NUM>, <NUM>. For example, each chain 6d may be at least partly made of, or covered by, an elastomer such as polyoxymethylene (POM). Alternatively, or in addition, the top surfaces may be covered by the same or similar materials.

One or more of the toothed wheels 6a,6b and/or one or both of the belts 6d, are connected to a driving mechanism comprising a driving motor (not shown). For example, one or both of the first toothed belt wheel(s) 6a of one or both of the belts 6d may function as a drive wheel which engages and drives its respective track <NUM>,<NUM>. Further, a second driving motor may be connected to one ore both of the second toothed belt wheels 6b for one or both of the tracks <NUM>,<NUM>.

By the arrangement of the first and second tracks <NUM>,<NUM> the service vehicle <NUM> of the system <NUM> is arranged to move horizontally in any direction on the rail system <NUM> by a control system <NUM> located onboard the service vehicle <NUM> or remote from the service vehicle <NUM> (see also <FIG>). If the control system <NUM> is onboard the service vehicle <NUM>, any movement pattern and speed settings may be conducted by any operator <NUM> located inside the service vehicle <NUM> by the operation of one or both of the first and second tracks <NUM>,<NUM> via its/their motor(s).

In the first embodiment, the container vehicle handling part <NUM> comprises a transfer device <NUM> which again includes one or more transfer beams 8b extending from the operational part <NUM>, a transfer motor 8c connected to the transfer beams 8b and an attachment device 8d operationally connected to the transfer motor 8c. In the particular embodiment shown in <FIG> the attachment device 8d comprises a lifting hook attached to a winch line spooled onto a rotatable drum 8e. However, a skilled person will understand that any mechanism capable of raising and lowering a container handling vehicle <NUM>,<NUM> relative to the underlying rail system <NUM> may be applied.

Further, the operational part <NUM> comprises an operating system <NUM> with a control stick to regulate the direction of the service vehicle <NUM> relative to the rail system <NUM> and a speed regulator to regulate to the speed of the service vehicle <NUM> relative to the rail system <NUM>. The operational part <NUM> further comprise an operator chair <NUM> and handles <NUM> on both sides of the vehicle body <NUM> for facilitating the exit and entrance of the operator <NUM> out of and into the operator chair <NUM>, respectively. The handles <NUM> may also be used for other purposes such as attachment points during lifting or lowering procedures of the service vehicle <NUM> on to the rail system <NUM>.

As is apparent in <FIG>, the length L of both caterpillar tracks <NUM>,<NUM> extends over several grid cells <NUM> to ensure stable operations on the rail system <NUM> in all horizontal directions.

The procedure for lifting up a container handling vehicle <NUM>,<NUM> according to the first embodiment is best seen in <FIG>. The operator <NUM> maneuvers the service vehicle <NUM> of the system <NUM> to a position where a container handling vehicle <NUM> to be serviced is adjacent to the part of the service vehicle <NUM> closest to the transfer device <NUM>. If needed, the operator <NUM> may fine adjust the horizontal position of the service vehicle <NUM> in order to ensure a horizontal position of the transfer device <NUM> ready for attachment to, and lifting of, the container handling vehicle <NUM>. In the particular configuration shown in <FIG>, the vehicle body <NUM> may be horizontally displaced relative to the tracks <NUM>,<NUM> as illustrated by the thick arrows, for example by use of a dedicated displacement motor and internal rail arrangement (not shown). When the container handling vehicle <NUM> has been raised to an elevated position above the tracks <NUM>,<NUM>, the operator <NUM> may displace the vehicle body <NUM> relative to the tracks <NUM>,<NUM> to a transport position where the container handling vehicle <NUM> is located at least partly within the horizontal extent of the tracks <NUM>,<NUM>, to ensure a high stability during horizontal movements of the service vehicle <NUM> on the rail system <NUM>.

<FIG> show a second embodiment of the service vehicle <NUM> of the system <NUM>. In this embodiment the transfer device <NUM> of the service vehicle <NUM> comprises a base plate 8a of width G being configured to support one or more container handling vehicles <NUM>,<NUM>. The width G should thus be adapted to the overall width of the container handling vehicles <NUM>,<NUM> and the number of container handling vehicles <NUM>,<NUM> to be serviced. For example, in order for the service vehicle <NUM> to allow transportation of at least one container handling vehicle <NUM>,<NUM>, the width G should be equal or larger than the corresponding width of the container handling vehicle <NUM>,<NUM>, thereby allowing entrance onto the base plate 8a.

The procedure for picking up a container handling device <NUM>,<NUM> by the service vehicle <NUM> according to the second embodiment may proceed in the following way:.

The unloading process, i.e. the transport of the one or more container handling vehicles <NUM>,<NUM> by the service vehicle <NUM> to a predetermined position onto the rail system <NUM> for regular operation, proceeds equal or similar to the above described loading process, but in reverse sequence.

With particular reference to <FIG>, the length of the caterpillar tracks <NUM>,<NUM> are in this example seen to extend across four grid cells <NUM>.

A grid cell <NUM> framing a grid opening <NUM> is marked in <FIG> with thick lines.

The tracks <NUM>,<NUM> are driven by aid of a belt motor and belt wheels 6a,6b arranged within the endless belts 6d at both belt ends.

<FIG> shows that the operator <NUM> operating the service vehicle <NUM> of the system may gain access to the rail system <NUM>, and thereby any components on the rail system <NUM>, by using the base plate 8a as support.

A third embodiment of the service vehicle <NUM> of the system is shown in <FIG> and <FIG>.

Similar to the first embodiment described above, the transfer device <NUM> comprises a winch arrangement having a support 8a supporting the container handling vehicle <NUM>,<NUM> from above, a lifting mechanism 8c in form of a rotatable handle and a transfer drum 8e connected to the lifting mechanism 8c. As for the first and second embodiments the caterpillar tracks <NUM>,<NUM> have a length L extending across about four grid cells <NUM> and spaced apart with a width G (see <FIG>). The minimum width of G should be equal to, or larger than, the overall width of the container handling vehicle(s) <NUM>,<NUM> to be serviced. Further, the looped chains 6d of the tracks <NUM>,<NUM> are driven by belt wheels 6a,6b arranged at both longitudinal lengths of the tracks <NUM>,<NUM>.

The procedure for picking up a container handling device <NUM>,<NUM> by the service vehicle <NUM> according to the third embodiment may proceed in the following way:.

With particular reference to <FIG>, the length of the tracks <NUM>,<NUM> are also in this example seen to extend across four grid cells <NUM>.

<FIG> show a fourth embodiment of a service vehicle <NUM> of the system <NUM> arranged on the rail system <NUM>. The vehicle body <NUM> comprises a security fence <NUM> which defines an enclosed area, for example a protective chamber for accommodating an operator/personnel <NUM>. The protective chamber is in the example shown in <FIG> arranged with seating <NUM> for the operator <NUM>.

The security fence <NUM> may be made of wall panels arranged on top of a horizontal base of the vehicle body <NUM>. Further, at least one of the wall panels may be made of transparent panels.

The transfer device <NUM> may in this embodiment be a hatch or any other pivotable device onto which one or more container handling vehicles <NUM>,<NUM> may be driven.

The procedure for transferring one or more container handling devices <NUM>,<NUM> from the service vehicle <NUM> to a location on the rail system <NUM> according to the fourth embodiment may proceed in the following way:.

As depicted in <FIG>, the operator <NUM> may in one exemplary configuration open an inspection door <NUM> at the side of the service vehicle <NUM>, for example opposite the side with the hatch <NUM>. Such a configuration may be useful to allow further manual inspection of the storage system <NUM>.

A fifth embodiment of the service vehicle <NUM> of the system <NUM> is illustrated in <FIG>. The embodiment is similar to the third embodiment (<FIG> and <FIG>) with the exception of the configuration and operation of the transfer device <NUM>.

Instead of a winched crane system 8c,8d,8e depicted in the third embodiment, the one or more container handling vehicles <NUM>,<NUM> are lifted by one or more lifting hooks 8d arranged onto the vehicle body <NUM> within the container vehicle handling part <NUM>. As for the above disclosed embodiments, the tracks <NUM>,<NUM> are spaced apart by a width G.

The term lifting hook 8d should be interpreted to include any gripping mechanism able to grip a container handling vehicle <NUM>,<NUM>.

In this fifth embodiment the lifting hook 8d is coupled to a lifting arrangement 8f,<NUM> enabling vertical movement of the lifting hook 8d. The lifting arrangement may for example comprise one or more vertical linear actuators 8f driving a frame <NUM> onto which the lifting hook 8d is mounted. The term 'vertical linear actuator' is herein defined as any linear actuator able to move in a direction having a significant non-zero vertical component. In a preferred example however, the vertical linear actuator is configured to perform a vertical movement with zero, or essentially zero, horizontal displacement.

The design of the lifting hook 8d (or alternative gripping mechanism) should be such that interaction with any exterior design of the vehicle body of the relevant container handling vehicle(s) <NUM>,<NUM> is allowed. For example, the vehicle body of each container handling vehicle <NUM>,<NUM> may comprise one or more receptacles <NUM> such as recesses / openings / rings into which the lifting hook(s) 8d may be inserted.

The operation of the lifting hook(s) 8d may be controlled by the operator <NUM> (manually and/or by an onboard control system <NUM>), by a remote control system or a combination thereof.

Further, the service vehicle <NUM> may be equipped by a registration unit <NUM> configured to aid an operator <NUM> to maneuver the service vehicle <NUM> safely to the final positions on the rail system <NUM>. The registration unit <NUM> may for example be an image capturing unit <NUM> comprising a forward camera 9a and a rearward camera 9b as illustrated in <FIG> and/or one or more rotatable cameras. The image capturing unit <NUM> may be any optical instrument for recording or capturing images. The images or films may be stored locally, transmitted to remote location, or a combination thereof.

The image capturing unit <NUM> may be controlled and visualized by an operator <NUM> onboard the service vehicle <NUM>, remotely or a combination thereof.

Further, the first to fifth embodiments of the service vehicle <NUM> of the system <NUM> have preferably an emergency stop button 12a as depicted in <FIG>, constituting part of the onboard control system <NUM>.

<FIG> show a sixth embodiment of the service vehicle <NUM> of the system <NUM>, in which all operations of the vehicle <NUM> are performed fully remote, that is, without any need for a human operator to directly interact with a control system onboard the vehicle <NUM> during the service procedure.

In the sixth embodiment, the service vehicle <NUM> comprises two caterpillar tracks <NUM>,<NUM> coupled to two opposite vertical sides of a vehicle body <NUM>. At least one of the two other vertical sides of the vertical body <NUM> is configured to receive at least one container handling vehicle <NUM>,<NUM> to be serviced.

<FIG> shows a particular configuration where service vehicle <NUM> comprises two guiding pins <NUM> attached to each of the opposite vertical sides of the vehicle body <NUM> onto which the caterpillar tracks <NUM>,<NUM> are connected. The ends of each guiding pins <NUM> nearest the container handling vehicle receiving side of the vehicle body <NUM> displays a wedge shape allowing the contain handling vehicle <NUM>,<NUM> to be guided correctly into the vehicle body <NUM>. A remotely operated registration unit <NUM> in form of a forward camera 9a and a rearward camera 9b is mounted on the top horizontal side of the vehicle body <NUM>.

The transfer device <NUM> comprises a lifting mechanism 8c which includes one or more vertical linear actuators 8f. Each of the actuators 8f has one end connected to a pivot support <NUM> pivotally couples to the vehicle body <NUM> with a rotational axis parallel to the underlying rail system <NUM> and the other end to a lifting claw 8d. The lifting claws 8d may be displaceable in a horizontal direction relative to the vehicle body <NUM> by use of horizontal linear actuators 8i, i.e. with a horizontal non-zero component.

The service vehicle <NUM> is remotely operated by a remote control system via one or more onboard transmitters <NUM>. Exemplary locations of such transmitters <NUM> may be on one, some or all of the vertical linear actuations as depicted in <FIG>. Alternatively, or in addition, similar transmitters <NUM> may be arranged on the vehicle body <NUM>, within the registration unit <NUM>, on one or both of the tracks <NUM>,<NUM>, etc..

As for the above disclosed embodiments the caterpillar tracks <NUM>,<NUM> have a length L extending across a plurality of grid cells <NUM>, preferably four or more.

In the sixth embodiment the opening of the vertical containing handling vehicle receiving side of the vehicle body <NUM>, including any guiding pins <NUM>, has a minimum width G being equal to, or larger than, the overall width of the container handling vehicle(s) <NUM>,<NUM> to be serviced.

The procedure for picking up a container handling device <NUM>,<NUM> by the service vehicle <NUM> according to the sixth embodiment may proceed in the following way:.

In all embodiments, the tracks <NUM>,<NUM> comprise looped chains 6d driven by toothed belt wheels 6a,6b arranged within the chains 6d. However, it may be envisaged configuration where one or more of the toothed wheels 6a,6b are arranged outside the looped chain 6d. Instead of toothed wheels <NUM>,<NUM>, the tracks <NUM>,<NUM> may comprise alternative drive mechanism such as wheels having other types of means for meshing or coupling to their respective chains 6d.

Even if only the sixth embodiment is disclosed without a dedicated space for a human operator, all the embodiments of the service vehicle <NUM> of the system may be easily configured to be maneuvered on the rail system <NUM> without the need for an onboard operator <NUM>, for example by operations performed entirely by a remotely located human operator <NUM> or by a fully or partly automated control system or a combination thereof.

It may also be envisaged embodiments where the full operation of the service vehicle <NUM> of the system <NUM> is partly due to the operation of an onboard operator and partly due to a remotely located human operator or alternatively a combination between the operation of an onboard operator and a fully or partly automated control system.

Claim 1:
An automated storage and retrieval system (<NUM>) comprising:
a rail system (<NUM>) comprising a first set of parallel rails (<NUM>) arranged in a horizontal plane (P) and extending in a first direction (X), and a second set of parallel rails (<NUM>) arranged in the horizontal plane (P) and extending in a second direction (Y) which is orthogonal to the first direction (X), which first and second sets of rails (<NUM>, <NUM>) form a grid pattern in the horizontal plane (P) comprising a plurality of adjacent grid cells (<NUM>);
at least one container handling vehicle (<NUM>,<NUM>) being configured to move on the rail system (<NUM>), wherein the at least one container handling vehicle (<NUM>,<NUM>) comprises a wheel arrangement (<NUM>,<NUM>) being configured to guide the at least one storage container vehicle (<NUM>,<NUM>) along the rail system (<NUM>) in at least one of the first direction (X) and the second direction (Y);
a service vehicle (<NUM>) for movement on the rail system (<NUM>), said service vehicle (<NUM>) being provided over the top of the rail system (<NUM>) and comprising:
- a container vehicle handling part (<NUM>) for mechanical interacting with the at least one container handling vehicle (<NUM>,<NUM>) operating on the rail system (<NUM>),
an operational part (<NUM>) for controlling operations of the service vehicle (<NUM>), and
propulsion means (<NUM>,<NUM>),
characterized in that the propulsion means (<NUM>,<NUM>) allow movement of the service vehicle (<NUM>) in any direction over the top of the rail system (<NUM>) during operation, wherein the propulsion means (<NUM>,<NUM>) comprises:
a first caterpillar track (<NUM>) comprising a longitudinal extending endless belt (6d),
a second caterpillar track (<NUM>) comprising a longitudinally extending endless belt (6d) directed parallel to the endless belt (6d) of the first caterpillar track (<NUM>),
a belt motor (6a) driving the endless belts (6d),
wherein the first and second caterpillar track (<NUM>,<NUM>) have, when moving over the top of the rail system (<NUM>) an overall length L exceeding the distance across two grid cells (<NUM>) in the first direction (X) and the second direction (Y), wherein movement of the caterpillar tracks (<NUM>,<NUM>) over the top of the rail system (<NUM>) signify that the caterpillar tracks (<NUM>,<NUM>) are supported on the rail system (<NUM>), but do not engage with the rails (<NUM>,<NUM>) themselves.