Container handling vehicle, storage systems and related method

Abstract

The present invention provides a container handling vehicle comprising: a vehicle body (9) and a container lifting assembly (18,5,8) for lifting a storage container The container lifting assembly comprises a horizontal lifting frame (18) for releasable connection to a storage container (106), a lifting shaft assembly comprising at least one lifting shaft (8a,8b) and four lifting elements (5). Each lifting element (5) has a lower end (14) connected at a corresponding corner section (6) of the lifting frame (18) and an upper end connected to the lifting shaft assembly (8), such that the lifting frame (18) may be raised or lowered by rotating the lifting shaft. The container handling vehicle comprises at least one sensor (7) for detecting and measuring inclination of the lifting frame relative to a horizontal plane. The container handling vehicle has a lifting element adjustment system comprising a set of actuators (10,11) and an actuator controller (19) in communication with the sensor (7). The set of actuators (10,11) is configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned towards or within the predetermined range relative to the horizontal plane. The present invention also provides a storage system and a method of controlling a container handling vehicle.

Description

CONTAINER HANDLING VEHICLE, STORAGE SYSTEMS AND RELATED METHODField of the invention

[0001] The present invention relates to a container handling vehicle having a container lifting assembly for lifting a storage container, storage systems, and a method of controlling a container handling vehicle.Background and prior art

[0002] Fig. 1 discloses a prior art automated storage and retrieval system 1 (i.e. a storage system), with a framework structure 100 and Figs. 2, 3 and 4 disclose three different prior art container handling vehicles 201,301,401 suitable for operating on such a system 1.

[0003] The framework structure 100 comprises upright members 102 and a storage volume comprising storage columns 105 arranged in rows between the upright members 102. In these storage columns 105 storage containers 106, also known as bins, are stacked one on top of one another to form stacks 107. The members 102 may typically be made of metal, e.g. extruded aluminium profiles.

[0004] The framework structure 100 of the automated storage and retrieval system 1 comprises a rail system 108 (i.e. a rail grid) arranged across the top of framework structure 100, on which rail system 108 a plurality of container handling vehicles 201,301,401 maybe operated to raise storage containers 106 from, and lower storage containers 106 into, the storage columns 105, and also to transport the storage containers 106 above the storage columns 105. The rail system 108 comprises a first set of parallel rails no arranged to guide movement of the container handling vehicles 201,301,401 in a first direction X across the top of the frame structure 100, and a second set of parallel rails 111 arranged perpendicular to the first set of rails no to guide movement of the container handling vehicles 201,301,401 in a second direction Y which is perpendicular to the first direction X. Containers 106 stored in the columns 105 are accessed by the container handling vehicles 201,301,401 through access openings 112 in the rail system 108. The container handling vehicles 201,301,401 can move laterally above the storage columns 105, i.e. in a plane which is parallel to the horizontal X-Y plane.

[0005] The upright members 102 of the framework structure 100 may be used to guide the storage containers during raising of the containers out fromand lowering of the containers into the columns 105. The stacks 107 of containers 106 are typically self-supportive.

[0006] Each prior art container handling vehicle 201,301,401 comprises a vehicle body 201a, 301a, 401a and a wheel assembly featuring first and second sets of wheels 201b, 201c, 301b, 301c, 401b, 401c which enable the lateral movement of the container handling vehicles 201,301,401 in the X direction and in the Y direction, respectively. In Figs. 2, 3 and 4 two wheels in each set are fully visible. The first set of wheels 201b, 301b, 401b is arranged to engage with two adjacent rails of the first set no of rails, and the second set of wheels 201c, 301c, 401c is arranged to engage with two adjacent rails of the second set 111 of rails. At least one of the sets of wheels 201b, 301b, 201c, 301c, 401b, 401c can be lifted and lowered, so that the first set of wheels 201b, 301b, 401b and / or the second set of wheels 201c, 301c, 401c can be engaged with the respective set of rails no, 111 at any one time.

[0007] Each prior art container handling vehicle 201,301,401 also comprises a lift or lifting device 404, see fig. 4, for vertical transportation of storage containers 106 (i.e. a container lifting device), e.g. raising a storage container 106 from, and lowering a storage container 106 into, a storage column 105. The lifting device 404 features a lifting frame 2 comprising container connectors 3, adapted to engage connecting recesses 13 at an upper rim of the sidewalls of a storage container 106, see fig. 5, and guiding pins 4. The guiding pins 4 are arranged to interact with guiding pin recesses 7 at the corners of the storage container and ensure a correct alignment of the lifting frame 2 and container connectors 3 relative to the storage container. The guiding pins 4 will also assist in guiding the lifting frame 2 relative to the upright members of the storage column 105. The lifting frame 2 can be lowered from the vehicle 201,301,401 so that the position of the lifting frame 2 with respect to the vehicle 201,301,401 can be adjusted in a third direction Z which is orthogonal the first direction X and the second direction Y. The lifting device of the container handling vehicle 201 is located within the vehicle body 201a in Fig. 2.

[0008] To raise or lower the lifting frame 2 (and optionally a connected storage container 106), the lifting frame 2 is suspended from a band drive assembly by lifting bands 5. In the band drive assembly, the lifting bands are commonly spooled on / off at least one rotating lifting shaft or reel arranged in the container handling vehicle. Various designs of band drive assemblies aredescribed in, for instance, WO 2015 / 193278 Al, WO 2017 / 129384 Al and WO 2019 / 206438 Al.

[0009] Conventionally, and also for the purpose of this application, =i identifies the uppermost layer for storing storage containers below the rail system 108, i.e. the layer immediately below the rail system 108, =2 the second layer below the rail system 108, Z=3 the third layer etc. In the exemplary prior art disclosed in Fig. 1, Z=8 identifies the lowermost, bottom layer of storage containers. Similarly, X=i...n and Y=i...n identifies the position of each storage column 105 in the horizontal plane. Consequently, as an example, and using the Cartesian coordinate system X, Y, Z indicated in Fig. 1, the storage container identified as 106’ in Fig. 1 can be said to occupy storage position A=17, Y=i, Z=6. The container handling vehicles 201,301,401 can be said to travel in layer Z=o, and each storage column 105 can be identified by its X and Y coordinates. Thus, the storage containers shown in Fig. 1 extending above the rail system 108 are also said to be arranged in layer Z=o.

[0010] The storage volume of the framework structure 100 has often been referred to as a grid 104, where the possible storage positions within this grid are referred to as storage cells. Each storage column may be identified by a position in an X- and T-direction, while each storage cell may be identified by a container number in the X-, Y- and Z-direction.

[0011] Each prior art container handling vehicle 201,301,401 comprises a storage compartment or space for receiving and stowing a storage container 106 when transporting the storage container 106 across the rail system 108. The storage space may comprise a cavity arranged internally within the vehicle body 201a as shown in Figs. 2 and 4 and as described in e.g. WO2O15 / 193278A1 and W02019 / 206487A1, the contents of which are incorporated herein by reference.

[0012] Fig. 3 shows an alternative configuration of a container handling vehicle 301 with a cantilever construction. Such a vehicle is described in detail in e.g. NO317366, the contents of which are also incorporated herein by reference.

[0013] The cavity container handling vehicles 201 shown in Fig. 2 may have a footprint that covers an area with dimensions in the X and Y directions which is generally equal to the lateral extent of a storage column 105, e.g. as is described in WO2O15 / 193278A1, the contents of which are incorporated herein by reference. The term 'lateral' used herein may mean 'horizontal'.

[0014] Alternatively, the cavity container handling vehicles 401 may have a footprint which is larger than the lateral area defined by a storage column 105 as shown in Fig. 1 and 4, e.g. as is disclosed in W02014 / 090684A1 or W02019 / 206487A1.

[0015] The rail system 108 typically comprises rails with grooves in which the wheels of the vehicles run. Alternatively, the rails may comprise upwardly protruding elements, where the wheels of the vehicles comprise flanges to prevent derailing. These grooves and upwardly protruding elements are collectively known as tracks. Each rail may comprise one track, or each rail may comprise two parallel tracks.

[0016] W02018 / 146304A1, the contents of which are incorporated herein by reference, illustrates a typical configuration of rail system 108 comprising rails and parallel tracks in both X and Y directions forming a rail grid.

[0017] In the framework structure 100, most of the columns 105 are storage columns 105, i.e. columns 105 where storage containers 106 are stored in stacks 107. However, some columns 105 may have other purposes. In Fig. 1, columns 119 and 120 are such special-purpose columns used by the container handling vehicles 201,301,401 to drop off and / or pick up storage containers 106 so that they can be transported to an access station (not shown) where the storage containers 106 can be accessed from outside of the framework structure 100 or transferred out of or into the framework structure 100. Within the art, such a location is normally referred to as a ‘port’ and the column in which the port is located maybe referred to as a ‘port column’ 119,120. The transportation to the access station maybe in any direction, that is horizontal, tilted and / or vertical. For example, the storage containers 106 maybe placed in a random or dedicated column 105 within the framework structure 100, then picked up by any container handling vehicle and transported to a port column 119,120 for further transportation to an access station. Note that the term ‘tilted’ means transportation of storage containers 106 having a general transportation orientation somewhere between horizontal and vertical.

[0018] In Fig. 1, the first port column 119 may for example be a dedicated drop-off port column where the container handling vehicles 201,301,401 can drop off storage containers 106 to be transported to an access or a transfer station, and the second port column 120 may be a dedicated pick-up port column where the container handling vehicles 201,301,401 can pick up storage containers 106 that have been transported from an access or a transfer station.

[0019] The access station may typically be a picking or a stocking station where product items are removed from or positioned into the storage containers 106. In a picking or a stocking station, the storage containers 106 are normally not removed from the automated storage and retrieval system 1 but are returned into the framework structure 100 again once accessed. A port can also be used for transferring storage containers to another storage facility (e.g. to another framework structure or to another automated storage and retrieval system), to a transport vehicle (e.g. a train or a lorry), or to a production facility.

[0020] A conveyor system comprising conveyors is normally employed to transport the storage containers between the port columns 119,120 and the access station.

[0021] If the port columns 119,120 and the access station are located at different levels, the conveyor system may comprise a lift device with a vertical component for transporting the storage containers 106 vertically between the port column 119,120 and the access station.

[0022] The conveyor system may be arranged to transfer storage containers 106 between different framework structures, e.g. as is described in W02014 / 075937A1, the contents of which are incorporated herein by reference. The conveyor system in WO2O14 / O75937A1 is a storage container lift arranged to transport a storage container between two vertically separated framework structures 100. A potential disadvantage of the storage container lift is that it is a potential single point of failure and repair of a defective storage container lift may be time-consuming.

[0023] When a storage container 106 stored in one of the storage columns 105 disclosed in Fig. 1 is to be accessed, one of the container handling vehicles 201,301,401 is instructed to retrieve the target storage container 106 from its position and transport it to the drop-off port column 119. This operation involves moving the container handling vehicle 201,301,401 to a location above the storage column 105 in which the target storage container 106 is positioned, retrieving the storage container 106 from the storage column 105 using the container handling vehicle’s 201,301,401 lifting device 404, and transporting the storage container 106 to the drop-off port column 119. If the target storage container 106 is located deep within a stack 107, i.e. with one or a plurality of other storage containers 106 positioned above the target storage container 106, the operation also involves temporarily moving the above-positioned storage containers prior to lifting the target storage container 106 from the storagecolumn 105. This step, which is sometimes referred to as “digging” within the art, may be performed with the same container handling vehicle that is subsequently used for transporting the target storage container to the drop-off port column 119, or with one or a plurality of other cooperating container handling vehicles. Alternatively, or in addition, the automated storage and retrieval system 1 may have container handling vehicles 201,301,401 specifically dedicated to the task of temporarily removing storage containers 106 from a storage column 105. Once the target storage container 106 has been removed from the storage column 105, the temporarily removed storage containers 106 can be repositioned into the original storage column 105. However, the removed storage containers 106 may alternatively be relocated to other storage columns 105.

[0024] When a storage container 106 is to be stored in one of the columns 105, one of the container handling vehicles 201,301,401 is instructed to pick up the storage container 106 from the pick-up port column 120 and transport it to a location above the storage column 105 where it is to be stored. After any storage containers 106 positioned at or above the target position within the stack 107 have been removed, the container handling vehicle 201,301,401 positions the storage container 106 at the desired position. The removed storage containers 106 may then be lowered back into the storage column 105 or relocated to other storage columns 105.

[0025] For monitoring and controlling the storage system 1, e.g. monitoring and controlling the location of respective storage containers 106 within the framework structure 100, the content of each storage container 106, and the movement of the container handling vehicles 201,301,401 so that a desired storage container 106 can be delivered to the desired location at the desired time without the container handling vehicles 201,301,401 colliding with each other, the storage 1 comprises a control system 500 which typically is computerized and which typically comprises a database for keeping track of the storage containers 106.

[0026] The practical lifting height of the lifting devices of the prior art container handling vehicles are limited to about 6 meters. The limitation to the lifting height is predominantly caused by non-homogenous thickness of the lifting bands which in turn leads to small differences in the lifting height of each individual lifting band when spooled on / off a lifting shaft or reel. These differences in lifting height of the individual lifting bands accumulate and willcause the lifting frame of the lifting device to tilt beyond an acceptable level when the lifting height of the lifting device exceeds about 6 m. Such excessive tilting of the lifting frame entails that the lifting frame may get stuck within the storage column. The lifting bands may in some cases be replaced by other lifting elements such as wires, cables or lines. Lifting devices featuring such lifting elements will also have a limited practical lifting height due to e.g. non- homogenous stretching of the lifting elements over time.

[0027] W02019 / 206482A1 discloses a manually adjustable lifting frame, wherein lifting bands, i.e. lifting elements, maybe adjusted at the connections between the lifting bands and the lifting frame. The lifting frame should be inspected visually at regular intervals to ensure it is horizontal to prevent any operational errors. The disclosed solution does not allow a lifting height above 6m.

[0028] In view of the above, it is desirable to provide a container-handling vehicle, and an automated storage and retrieval system comprising said container-handling vehicle, wherein the lifting devices are improved.Summary of the invention

[0029] This summary is provided to introduce in simplified form a selection of concepts that are further described herein. The summary is not intended to identify key or essential features of the invention.

[0030] The present invention is defined by the attached claims and in the following:

[0031] In a first aspect, the present invention provides a storage system as defined in any of appended clauses 1 to 14 and / or a storage system as defined in any of appended claims 16 to 18. Such a storage system may comprise a framework structure and at least one container-handling vehicle, the framework structure comprises multiple storage columns, in which storage containers may be stored on top of one another in vertical stacks, and the container handling vehicle is for operating on a rail grid at an upper level of the framework structure for retrieving storage containers from, and storing storage containers in, the storage columns below, and for transporting the storage containers horizontally across the rail system, wherein the vehicle comprises a container lifting assembly for lifting a storage container and a vehicle body,the container lifting assembly comprises a horizontal lifting frame for releasable connection to a storage container, a lifting shaft assembly comprising at least one lifting shaft and four lifting elements, each lifting element has a lower end connected at a corresponding corner section of the lifting frame and an upper end connected to the lifting shaft assembly, such that the lifting frame may be raised or lowered by rotating the lifting shaft; the container handling vehicle comprises at least one sensor for detecting and measuring inclination of the lifting frame relative to a horizontal plane, and the container handling vehicle has a lifting element adjustment system comprising a set of actuators and an actuator controller in communication with the sensor, the set of actuators is configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane.

[0032] The storage system may be an automated storage and retrieval system.

[0033] The lifting elements may be lifting bands, wires, cables or lines.

[0034] The lifting elements may be lifting bands, and the lifting element adjustment system may be termed a lifting band adjustment system.

[0035] The lifting frame may comprise the at least one sensor, i.e. the sensor is arranged on the lifting frame.

[0036] The set of actuators may be configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned to within the predetermined range relative to the horizontal plane.

[0037] The set of actuators may be configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative tothe horizontal plane, such that the inclination of the lifting frame is returned closer to or within the predetermined range relative to the horizontal plane.

[0038] The set of actuators may be configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is brought towards or within the predetermined range relative to the horizontal plane.

[0039] The set of actuators may be configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned towards or to within the predetermined range relative to the horizontal plane.

[0040] The set of actuators may be configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned towards or within the predetermined range relative to the horizontal plane.

[0041] The set of actuators may be configured to interact with at least three of the lifting elements to attempt adjusting the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned towards or to within the predetermined range relative to the horizontal plane.

[0042] The lifting frame may comprise four corner sections, each corner section may comprise a separate corner of the lifting frame. The lifting frame may have a substantially rectangular horizontal periphery defining a horizontal area and each corner section may constitute about a quarter of the horizontal area of the lifting frame.

[0043] The predetermined range relative to the horizontal plane may e.g. be between -50and +50, between -30and +30, between -20and +20or between - 1° and +1°.

[0044] In other words, the set of actuators is configured to interact with at least three of the lifting elements to independently adjust the vertical distance between each of at least three of the corner sections and the lifting shaft assembly.

[0045] The actuator controller may provide control signals separately to each of the actuators based on the inclination measured by the sensor. The control signals may be obtained by an algorithm configured to provide the desired adjustment of the inclination of the lifting frame by a minimum adjustment of the vertical distance.

[0046] The set of actuators may be configured to interact with at least three of the lifting elements to continuously adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane.

[0047] The set of actuators may be configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to control signals from the actuator controller, the control signals being obtained based on a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane. The control signals control the actuators such that the inclination of the lifting frame is returned to within the predetermined range relative to the horizontal plane.

[0048] The storage system may comprise a control system for controlling movements of the at least one container handling vehicle, and the sensor may be in communication with a vehicle control module of the container handling vehicle, optionally via the actuator controller, the vehicle control module is configured to communicate data between the container handling vehicle and the control system.

[0049] The vehicle control module may be configured to communicate data from the sensor, and / or data from the actuator controller, indicating aninclination of the lifting frame outside the predetermined range relative to the horizontal plane, to the control system.

[0050] The control system may be configured to direct the container handling vehicle to a service area of the storage system, or provide an alert to an operator, if data received from the vehicle control module shows that the lifting element adjustment system is unable to return the inclination of the lifting frame towards and to within the predetermined range relative to the horizontal plane. The alert may inform an operator that the container handling vehicle needs service.

[0051] The set of actuators may comprise at least three separate actuators, each actuator configured to interact with a respective lifting element. The set of actuators may comprise four separate actuators, each actuator configured to interact with a respective lifting element.

[0052] The at least three lifting elements comprise four lifting elements.

[0053] The actuators may be independently controllable. That is, such that the vertical length of a lifting element extending between any of the corner sections and the lifting shaft assembly may be adjusted independently.

[0054] The lower end of each of the at least three lifting elements may be connected to a respective actuator. The set of actuators may comprise four separate actuators and each of the lower ends of the lifting elements may be connected to one of the actuators, i.e. each lower end is connected to a separate actuator such that each lifting element may be adjusted independently.

[0055] The lifting frame may comprise a lifting element guide at each of at least three of the corner sections, each guide is configured to change the direction of a respective lifting element from a vertical direction (i.e. the vertical direction of the lifting element between the lifting frame and the lifting shaft assembly) to a horizontal direction, and each of the actuators is coupled to a respective lower end of one of the at least three lifting elements and configured to move the lower end in the horizontal direction, such that the distance between the guide and the lower end may be adjusted. The lower end of a lifting element may also be termed a lifting frame end.

[0056] The lifting element guide may be a guide wheel or shaft having a horizontal centreline or axis, i.e. the centreline or axis is horizontal when thelifting frame is horizontal. The horizontal centreline or axis is parallel to a width direction of the lifting element.

[0057] Each of the actuators may be a linear actuator configured to move the respective lower end between a first position and a second position, the first position being closer to the guide than the second position. When the lower end is moved from the first position to the second position, the vertical distance between the corresponding corner section and the lifting shaft assembly is reduced / shortened.

[0058] The lifting element adjustment system may comprise four lifting element interaction rollers arranged in an upper portion of the container handling vehicle, each roller operated by one of the actuators and configured to move a respective lifting element away from the vertical such that the vertical distance between any of the corner sections and the lifting shaft assembly may be adjusted.

[0059] Each of the rollers may be mounted to an arm operated by the respective actuator. The arm may be actuated in a linear or curved manner. The arm may be a pivot arm or lever.

[0060] The actuator controller may control the actuators based on data received from the sensor. The actuator controller maybe arranged on / in the lifting frame or on / in the vehicle body.

[0061] The sensor and / or the actuators may be powered by a battery. The battery may be arranged in the lifting frame or in the vehicle body of the container handling vehicle. In the latter instance, power may be transferred from the battery to the sensor and actuators via the lifting elements. The battery powering the sensor and / or the actuators may be a main battery which also powers the operation of the container handling vehicle, i.e. operations such as movement of the container handling vehicle, lifting / lowering of the lifting frame etc.

[0062] The container handling vehicle comprises a main battery for powering movement of the vehicle, for powering rotation of the lifting shaft assembly and for powering the sensor and the actuators. The main battery may be rechargeable and arranged within the vehicle body of the container handling vehicle.

[0063] The actuators are configured to continuously keep the respective lifting element under tension. In other words, each actuator interacts with the respective lifting element such that the lifting element will have a tension of more than o N. In this manner slack of the lifting bands is prevented. Slack lifting elements may cause improper spooling onto the lifting shafts, increased wear (i.e. reduced lifetime of the equipment) and also excessive noise.

[0064] The storage system may comprise a rail grid on which the container handling vehicle may move in the two perpendicular directions, the rail grid being arranged above the storage columns.

[0065] The framework structure may comprise a plurality of vertical column profiles defining the storage columns. The rail grid may be arranged on top of, and supported by, the vertical column profiles. The rail grid may comprise a first set of parallel rails arranged to guide movement of the container handling vehicle in a first direction across the top of the framework structure, and a second set of parallel rails arranged perpendicular to the first set of rails to guide movement of the container handling vehicle in a second direction being perpendicular to the first direction.

[0066] The container handling vehicle may comprise a wheel assembly featuring first and second sets of wheels which enable movement of the container lifter in in the two perpendicular directions on the rail grid. The first set of wheels may be arranged to engage with a first set of parallel rails of the rail system, and the second set of wheels may be arranged to engage with a second set of parallel rails of the rail system. At least one of the sets of wheels can be lifted and lowered relative to the other set of wheels, so that the first set of wheels and / or the second set of wheels can be engaged with the respective set of rails at any one time.

[0067] The at least one sensor may be any suitable electronic inclination sensor suitable for continuously or regularly measuring the inclination of a plane relative to the horizontal, as well as transmitting the measurements to the lifting element adjustment assembly. The at least one sensor may be termed an inclination sensor, inclinometer or gyroscope (preferably a MEMS gyroscope), and suitable sensors are discussed in e.g. https: / / en.wikipedia.org / wiki / lnclinometer and https: / / en.wikipedia.org / wiki / Gyroscope.[oo68] In a second aspect, the present invention provides a container handling vehicle as defined in appended clause 15 and / or a container handling vehicle as defined in any of appended claims 1 to 15. Such a container handling vehicle may be for use with a storage system according to any embodiment of the first aspect. The container handling vehicle may comprise a container lifting assembly for lifting a storage container, a vehicle body and a wheel assembly, the wheel assembly comprises a first set of wheels and a second set of wheels enabling movement of the container handling vehicle in two perpendicular directions on a rail grid, the container lifting assembly comprises a horizontal lifting frame for releasable connection to a storage container, a lifting shaft assembly comprising at least one lifting shaft and four lifting elements, each lifting element has a lower end connected at a corresponding corner section of the lifting frame and an upper end connected to the lifting shaft assembly, such that the lifting frame may be raised or lowered by rotating the lifting shaft; the container handling vehicle comprises at least one sensor for detecting and measuring inclination of the lifting frame relative to a horizontal plane, and the container handling vehicle has a lifting element adjustment system comprising a set of actuators and an actuator controller in communication with the sensor, the set of actuators is configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned to within the predetermined range relative to the horizontal plane.

[0069] The container handling vehicle may comprise any of the features disclosed in connection with the container handling vehicle of the storage system according to the first aspect.

[0070] In a third aspect, the present invention provides a method as defined in any of appended clauses 16 to 17 and / or a method as defined in any of appended claims 19 to 20. Such a method maybe a method of controlling a container handling vehicle in a storage system according to any embodiment of the first aspect, the method comprising:raising or lowering the lifting frame while simultaneously detecting and measuring any inclination of the lifting frame relative to a horizontal plane by use of the sensor;- detecting an inclination of the lifting frame being outside the predetermined range relative to the horizontal plane; and- operating the set of actuators to adjust the vertical distance between at least one of the corner sections and the lifting shaft assembly, such that the detected inclination of the lifting frame is returned towards or within the predetermined range relative to the horizontal plane.

[0071] The method may comprise:- detecting an inclination of the lifting frame being outside the predetermined range relative to the horizontal plane after operating the set of actuators; and- directing the container handling vehicle to a service area, or- providing an alert from the control system to an operator.

[0072] In a fourth aspect, the present invention provides a storage system as defined in any of appended clauses 18 to 20 and / or a storage system as defined in any of appended claims 21 to 23. Such a storage system may comprise a framework structure, a control system and at least one container-handling vehicle, the framework structure comprises multiple storage columns, in which storage containers may be stored on top of one another in vertical stacks, and the container handling vehicle is for operating on a rail grid at an upper level of the framework structure for retrieving storage containers from, and storing storage containers in, the storage columns below, and for transporting the storage containers horizontally across the rail system, wherein the vehicle comprises a container lifting assembly for lifting a storage container and a vehicle body, the container lifting assembly comprises a horizontal lifting frame for releasable connection to a storage container, a lifting shaft assembly comprising at least one lifting shaft and four lifting elements, each lifting element has a lower end connected at a corresponding corner section of the lifting frame and an upper end connected to the lifting shaft assembly, such that the lifting frame may be raised or lowered by rotating the lifting shaft;the container handling vehicle comprises at least one sensor for detecting and measuring inclination of the lifting frame relative to a horizontal plane; and the control system is for controlling movements of the at least one container handling vehicle, and the sensor is in communication with a vehicle control module of the container handling vehicle, the vehicle control module is configured to communicate data between the sensor and the control system.

[0073] The vehicle control module may be configured to communicate data from the sensor indicating an inclination of the lifting frame outside a predetermined range relative to the horizontal plane, to the control system.

[0074] The control system may be configured to direct the container handling vehicle to a service area of the storage system, or provide an alert to an operator, if data received from the sensor shows that the inclination of the lifting frame is outside a predetermined range relative to the horizontal plane. The alert may inform an operator that the container handling vehicle needs service.

[0075] The storage system according to the fourth aspect may comprise any features of the storage system according to the first aspect. The storage system of the first aspect and / or the container handling vehicle of the second aspect may comprise the control system of the fourth aspect.Brief description of the drawings

[0076] Embodiments of the invention are described in detail, and by way of example only, with reference to the following drawings:

[0077] Fig. 1 is a perspective view of a framework structure of a prior art automated storage and retrieval system.

[0078] Fig. 2 is a perspective view of a prior art container handling vehicle having a centrally arranged cavity for carrying storage containers therein.

[0079] Fig. 3 is a perspective view of a prior art container handling vehicle having a cantilevered section for carrying storage containers underneath.

[0080] Fig. 4 is a perspective view of a prior art container handling vehicle, wherein a container lifting assembly is shown.

[0081] Fig. 5 is a perspective view of a storage container as used in the storage system in fig. 1.

[0082] Figs. 6 to 9 show a first exemplary container handling vehicle according to the invention.

[0083] Figs. 10 to 14 show a second exemplary container handling vehicle according to the invention.Detailed description of the invention

[0084] In overview, a container handling vehicle is provided which comprises a vehicle body (9) and a container lifting assembly (18,5,8) for lifting a storage container. The container lifting assembly comprises a horizontal lifting frame (18) for releasable connection to a storage container (106). The container lifting assembly also comprises a lifting shaft assembly comprising at least one lifting shaft (8a, 8b) and four lifting elements (5) which maybe lifting bands, wires, cables or lines. Each lifting element (5) has a lower end (14) connected at a corresponding corner section (6) of the lifting frame (18) and an upper end connected to the lifting shaft assembly (8), such that the lifting frame (18) may be raised or lowered by rotating the lifting shaft. At least one sensor (7) for detecting and measuring any inclination of the lifting frame relative to a horizontal plane is provided. The container handling vehicle has a lifting element adjustment system comprising a set of actuators (10,11) and an actuator controller in communication with the sensor. The set of actuators is configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned within the predetermined range relative to the horizontal plane.

[0085] In the following, embodiments of the invention will be discussed in more detail with reference to the appended drawings. The embodiments of the invention are described byway of example only. For example, the drawings are not intended to limit the invention to the illustrated subject-matter.

[0086] As discussed above, the practical lifting height of the lifting devices of the prior art container handling vehicles are limited to about 6 meters. Consequently, the height of the prior art storage systems, i.e. the number ofstorage containers that may be stacked on top of another in vertical stacks are limited. In some instances, it would be desirable to extend the height of such storage systems to allow increased utilization of a building space. It would further be advantageous to have a means for alerting the control system 500 of a storage system when a lifting frame is inclined beyond a predetermined range relative to the horizontal to minimize the risk of having a lifting frame 2 being stuck in a storage column.

[0087] This description describes two exemplary container handling vehicles 17,17’ having lifting devices which allow for an increased lifting height.

[0088] The exemplary container handling vehicles 17,17’ are configured to be used in storage systems such as the one shown in fig. 1. Thus, an exemplary storage system according to the invention will comprise a framework structure 100, storage containers 106 and an exemplary container handling vehicle 17,17’. The framework structure 100 and the storage containers 106 may be similar to the corresponding features of the prior art system in fig. 1.

[0089] The framework structure 100 features vertical column profiles 102, which define a plurality of storage columns 105, and a grid-shaped rail system 108 arranged above the storage columns 105.

[0090] A first exemplary container handling vehicle 17 is shown in figs. 6-9. The container handling vehicle 17 comprises a first set of wheels 28 and a second set of wheels 29 for moving in two perpendicular directions on the rail system 108. The sets of wheels maybe as described for the prior art container handling vehicles in figs. 2-4.

[0091] The container handling vehicle features a container lifting assembly 18,5,8, for lifting a storage container 106, and a vehicle body 9. The container lifting assembly comprises a horizontal lifting frame 18 for releasable connection to a storage container 106, two rotatable lifting shafts 8a, 8b (i.e. a lifting shaft assembly) and four lifting bands 5 (i.e. lifting elements). Each of the lifting bands 5 has a lower end 14 connected at a corresponding corner section 6 of the lifting frame 18 and an upper end connected to one of the lifting shafts 8a, 8b. In this manner, the lifting frame 18 may be raised or lowered by rotating the lifting shafts 8a, 8b.

[0092] The lifting frame 18 comprises a sensor 7 for detecting and measuring any inclination of the lifting frame 18 relative to a horizontal plane.The sensor 7 is configured to communicate with a lifting element adjustment system. The lifting element adjustment system comprises a set of rotary actuators 10 (i.e. electric motors providing a rotational movement) and an actuator controller 19. Each actuator 10 is configured to move a respective pivot arm 12 to which arm a band interaction roller 15 (i.e. lifting element interaction roller) is mounted.

[0093] The band interaction rollers 15 are configured to interact with the lifting bands 5 to adjust the vertical distance between the corner sections 6 and the lifting shafts 8a, 8b in response to a detected inclination of the lifting frame 18 being outside a predetermined range relative to the horizontal plane. That is, the band interaction rollers 15 (i.e. lifting element interaction rollers) may interact with the lifting bands 5 such that the inclination of the lifting frame 18 is returned to within the predetermined range relative to the horizontal plane. The inclination of the lifting frame should at least be within a predetermined range of between -50and +50relative to horizontal. When the inclination of the lifting frame 18 exceeds the predetermined range the lifting frame 18 is at risk of becoming stuck inside a storage column in which the lifting frame is moved in a vertical direction.

[0094] The band interaction rollers 15 can adjust the vertical distance between the corner sections 6 and the lifting shafts 8a, 8b by moving a respective lifting band 5 away from or towards the vertical such that the vertical distance between any of the corner sections 6 and the lifting shaft assembly may be adjusted. The effect of moving a lifting band 5 away from the vertical and the corresponding shortening of the distance D between a corner section 6 and a lifting shaft 8b is illustrated in figs. 8 and 9.

[0095] In addition to adjusting the vertical distance between the corner sections 6 and the lifting shafts 8a, 8b, a further function of the actuators 10 is to prevent slack in the lifting bands. To prevent slack the actuators 10 are configured to continuously keep the lifting bands under tension, i.e. by ensuring that the lifting bands have a static tension of more than oN and less than what is needed to cause positional change of the lifting frame 2.

[0096] The actuator controller 19 may provide control signals separately to each of the actuators based on the inclination, i.e. roll and pitch, measured by the sensor 7. The control signals may e.g. be obtained by an algorithm configured to provide the desired adjustment of the inclination of the lifting frame 18 by a minimum of incremental adjustments of any of the lifting bands 5.

[0097] The sensor 7 and lifting band adjustment system provides automatic adjustment of any inclination of the lifting frame 18. In this manner, the risk of having the lifting frame 18 becoming stuck within a storage column 105 is minimized and the lifting height / distance of the lifting frame 18 may consequently be increased significantly relative to the prior art.

[0098] In rare instances, the lifting band adjustment system may not be sufficient to correct an excessive inclination of the lifting frame 18. This may e.g. occur due to errors in components of the lifting band adjustment system or when the inclination of the lifting frame is too large for the lifting band adjustment system to fully correct. To prevent unnecessary downtime of an exemplary storage system 1 due to such instances, the sensor 7 is configured to be in communication with a vehicle control module (not shown) of the container handling vehicle 17. The vehicle control module communicates with a computerized control system 500, see fig. 1, of the exemplary storage system 1. The control system 500 typically comprises a database for keeping track of the storage containers 106 and is configured to control the operation of the container handling vehicle 17. By having the sensor 7 able to communicate with the control system 500 via the vehicle control module, the control system 500 may direct the container handling vehicle 17 to a service area of the storage system 1 if data received from the vehicle control module shows that the lifting band adjustment system is unable to return the inclination of the lifting frame to within the predetermined range relative to the horizontal plane. Alternatively, or additionally, the control system may issue an alert such that an operator may access the storage system 1 and provide service to the container handling vehicle 17 if the lifting band adjustment assembly is unable to sufficiently adjust the lifting frame.

[0099] The sensor 7 may communicate with the vehicle control module wirelessly or via the lifting bands 5. The lifting bands may be made of a metal or a synthetic material. When the lifting bands are made of a synthetic material, they may comprise signal and / or power cables allowing transfer of data from the sensor 7 to the vehicle control module. In alternative embodiments, the lifting bands may be other types of lifting elements, such as wires, cables or lines. In such cases, the sensor may communicate with the vehicle control module wirelessly or via signal / power cables embedded in the lifting elements 5.

[0100] The sensor 7 and the actuators 10 may be powered by a battery. The battery may be arranged in the lifting frame 18 or in the container handlingvehicle 17. In the latter instance, power may be transferred from the battery to the sensor 7 and actuators 10 via the lifting bands 5.

[0101] The sensor 7 is arranged to measure the inclination, e.g. pitch and roll, of a reference surface or plane of the lifting frame 18, the reference surface or plane is configured to be horizontal when all corner sections 6 are at an equal vertical distance from the lifting shaft assembly, i.e. when the lifting frame 18 is horizontal.

[0102] The sensor 7 may be any suitable electronic inclination sensor for continuously or regularly measuring the inclination of a plane relative to the horizontal. The sensor 7 is configured to directly or indirectly transmit the measurements to the actuator controller 19. The sensor 7 maybe an inclination sensor, inclinometer or gyroscope (e.g. a MEMS gyroscope), and suitable sensors are discussed in e.g. https: / / en.wikipedia.org / wiki / lnclinometer and https: / / en.wikipedia.org / wiki / Gyroscope. In alternative embodiments, the sensor may comprise a plurality of laser modules arranged in the vehicle or the lifting frame to measure the distance between the corner sections of the lifting frame and a horizontal reference plane of the vehicle. Any difference in distance may be used to calculate the inclination of the lifting frame.

[0103] A second exemplary container handling vehicle 17’ is shown in figs. 10- 14. The container handling vehicle comprises a first set of wheels 28 and a second set of wheels 29 for moving in two perpendicular directions on the rail system 108. The sets of wheels maybe as described for the prior art container handling vehicles in figs. 2-4.

[0104] The container handling vehicle features a container lifting assembly 18,5,8, for lifting a storage container 106, and a vehicle body 9. The container lifting assembly comprises a horizontal lifting frame 18 for releasable connection to a storage container 106, two rotatable lifting shafts 8a, 8b (i.e. a lifting shaft assembly) and four lifting bands 5 (i.e. lifting elements). Each of the lifting bands 5 has a lower end 14 connected at a corresponding corner section 6 of the lifting frame 18 and an upper end connected to one of the lifting shafts 8a, 8b. In this manner, the lifting frame 18 may be raised or lowered by rotating the lifting shafts 8a, 8b.

[0105] Similar to the first exemplary container handling vehicle 17, the lifting frame 18 comprises a sensor 7 for detecting and measuring any inclination of the lifting frame 18 relative to a horizontal plane. The sensor 7 isconfigured to communicate with a lifting band adjustment system. The lifting band adjustment system comprises a set of linear actuators n (e.g. an electric linear actuator) and an actuator controller 19. The sensor 7 maybe in communication with a vehicle control module and a control system 500 as described for the first exemplary container handling vehicle 17. The second exemplary container handling vehicle 17’ comprises the same features as described above for the first exemplary container handling vehicle 17 except the specific configuration of the lifting band adjustment system.

[0106] The lifting frame 18 comprises a guide wheel 13 (i.e. a lifting element guide) at each of the four corner sections 6. Each guide wheel 13 is configured to change the direction of a respective lifting band 5 from a vertical direction to a horizontal direction. The actuators 11 are coupled to respective lower ends 14 of the lifting bands and are configured to move the lower ends in the horizontal direction, such that the distance between the guide wheel 13 and the lower end 14, and thus the vertical distance between each corner section 6 and the lifting shafts 8a, 8b, may be adjusted. The configuration using guide wheels 13 and horizontally aligned linear actuators 11 provides a low build lifting frame which may be mounted to any of the prior art container handling vehicles (i.e. to replace a prior art lifting frame 2) without requiring any substantial modification of the vehicle body. Each of the actuators 11 may independently move the respective lower end 14 between a first position, see figs. 10 and 12, and a second position, see figs. 11 and 13, the first position being closer to the guide wheel 13 than the second position.

[0107] The actuators 11 are configured to continuously keep the respective lifting band 5 under tension to avoid slack. This may e.g. be obtained by having the actuators 11 continuously pulling on the respective lifting band by a force of slightly above o N when the inclination of the lifting frame is within the predetermined range relative to the horizontal plane.List of reference numbers1 Prior art automated storage and retrieval system2 Lifting frame, prior art lifting frame3 Container connector4 Guiding pin5 Lifting bands, lifting elements6 Corner section7 Guiding pin recess8 a, 8b Lifting shaft9 Vehicle body10 Actuator, rotary actuator11 Actuator, linear actuator12 Pivot arm13 Guide wheel14 Lower end of lifting element15 Band interaction roller16 Upper rim of storage container1747’ Container handling vehicle18 Lifting frame19 Actuator controller 28,28’ First set of wheels 29,29’ Second set of wheels 100,100’ First framework structure, second framework structure 102 Upright members of framework structure103 Horizontal members of framework structure104 Storage grid105 Storage column 106 Storage container 106’ Particular position of storage container107 Stack 108 Rail system110 Parallel rails in first direction ( )110a First rail in first direction (X) 110b Second rail in first direction (X)111 Parallel rail in second direction (V)111a First rail of second direction (Y) mb Second rail of second direction (Y)112 Access opening, storage column113 Access opening, buffer column119 First port column 120 Second port column201 Prior art container handling vehicle 201a Vehicle body of the container handling vehicle 201 201b Drive means / wheel arrangement, first direction (X) 201c Drive means / wheel arrangement, second direction (Y)301 Prior art cantilever container handling vehicle 301a Vehicle body of the container handling vehicle 301 301b Drive means in first direction (X) 301c Drive means in second direction (Y) 401 Prior art container handling vehicle401a Vehicle body of the container handling vehicle 401 401b Drive means in first direction (X) 401c Drive means in second direction (Y) Y Second directionZ Third directionPAGE INTENTIONALLY LEFT BLANKClausesAspects and features of the invention are set forth in the following numbered clauses. i. A storage system comprising a framework structure (100) and at least one container handling vehicle (17,17’), the framework structure (100) comprises multiple storage columns (105), in which storage containers (106) maybe stored on top of one another in vertical stacks (107), and the container handling vehicle is for operating on a rail grid (108) at an upper level of the framework structure for retrieving storage containers (106) from, and storing storage containers in, the storage columns below, and for transporting the storage containers horizontally across the rail system (108), wherein the container handling vehicle comprises a container lifting assembly (18,5,8) for lifting a storage container and a vehicle body (9), the container lifting assembly comprises a horizontal lifting frame (18) for releasable connection to a storage container (106), a lifting shaft assembly comprising at least one lifting shaft (8a, 8b) and four lifting elements (5), each lifting element (5) has a lower end (14) connected at a corresponding corner section (6) of the lifting frame (18) and an upper end connected to the lifting shaft assembly (8), such that the lifting frame (18) may be raised or lowered by rotating the lifting shaft; the container handling vehicle comprises at least one sensor (7) for detecting and measuring inclination of the lifting frame relative to a horizontal plane, and the container handling vehicle has a lifting element adjustment system comprising a set of actuators (10,11) and an actuator controller (19) in communication with the sensor (7), the set of actuators (10,11) is configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned towards or within the predetermined range relative to the horizontal plane.2. A storage system according to clause 1, comprising a control system (500) for controlling movements of the at least one container handling vehicleand wherein the sensor (7) is in communication with a vehicle control module of the container handling vehicle, the vehicle control module is configured to communicate data between the container handling vehicle and the control system (500). A storage system according to clause 2, wherein the control system (500) is configured to direct the container handling vehicle to a service area of the storage system, or provide an alert to an operator, if data received from the vehicle control module shows that the lifting element adjustment system is unable to return the inclination of the lifting frame to within the predetermined range relative to the horizontal plane. A storage system according to any of the preceding clauses, wherein the set of actuators comprises at least three separate actuators, each actuator configured to interact with a respective lifting element. A storage system according to clause 4, wherein the actuators are independently controllable. A storage system according to clause 4 or 5, wherein the lower end (14) of each of the at least three lifting elements (5) is connected to a respective actuator (11). A storage system according to clause 6, wherein the lifting frame (18) comprises a lifting element guide (13) at each of at least three of the corner sections (6), each guide is configured to change the direction of a respective lifting element from a vertical direction to a horizontal direction, and the actuators is coupled to a respective lower end (14) of one of the at least three lifting elements and configured to move the lower end in the horizontal direction. A storage system according to clause 7, wherein the lifting element guide is a guide wheel (13) or shaft having a horizontal centreline. A storage system according to clause 7 or 8, wherein each of the actuators is a linear actuator (11) configured to move the respective lower end between a first position and a second position, the first position closer to the lifting element guide than the second position. A storage system according to any of clauses 1 to 5, wherein the lifting element adjustment system comprises four lifting element interactionrollers (15) arranged in an upper portion of the container handling vehicle, each roller operated by one of the actuators and configured to move a corresponding lifting element away from the vertical such that the vertical distance between any of the corner sections and the lifting shaft assembly may be adjusted. A storage system according to clause 10, wherein each of the rollers is mounted to a pivot arm (12) operated by the respective actuator. A storage system according to any of the preceding clauses, wherein the actuator controller (19) controls the actuators (10,11) based on data received from the sensor (7). A storage system according to any of the preceding clauses, wherein the actuators (10, 11) are configured to continuously keep the respective lifting element (5) under tension. A storage system according to any of the preceding clauses, wherein the lifting elements are lifting bands (5), wires, cables or lines. A container handling vehicle for use in a storage system according to any of the preceding clauses, wherein the vehicle comprises a container lifting assembly (18,5,8) for lifting a storage container, a vehicle body (9) and a wheel assembly, the wheel assembly comprises a first set of wheels and a second set of wheels enabling movement of the container handling vehicle in two perpendicular directions on a rail grid, the container lifting assembly comprises a horizontal lifting frame (18) for releasable connection to a storage container (106), a lifting shaft assembly comprising at least one lifting shaft (8a, 8b) and four lifting elements (5), each lifting element (5) has a lower end (14) connected at a corresponding corner section (6) of the lifting frame (18) and an upper end connected to the lifting shaft assembly (8), such that the lifting frame (18) may be raised or lowered by rotating the lifting shaft; the container handling vehicle comprises at least one sensor (7) for detecting and measuring any inclination of the lifting frame relative to a horizontal plane, and the container handling vehicle has a lifting elementadjustment system comprising a set of actuators (10,11) and an actuator controller in communication with the sensor, the set of actuators is configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned within the predetermined range relative to the horizontal plane.16. A method of controlling a container handling vehicle in a storage system according to any of clauses 1-14, the method comprising:- raising or lowering the lifting frame (18) while simultaneously detecting and measuring any inclination of the lifting frame relative to a horizontal plane by use of the sensor;- detecting an inclination of the lifting frame being outside the predetermined range relative to the horizontal plane; and- operating the set of actuators to adjust the vertical distance between at least one of the corner sections and the lifting shaft assembly, such that the detected inclination of the lifting frame is returned towards or within the predetermined range relative to the horizontal plane.17. A method according to clause 16, comprising:- detecting an inclination of the lifting frame being outside the predetermined range relative to the horizontal plane after operating the set of actuators; and- directing the container handling vehicle to a service area, or- providing an alert from the control system to an operator.18. A storage system comprising a framework structure, a control system and at least one container-handling vehicle, the framework structure comprises multiple storage columns, in which storage containers may be stored on top of one another in vertical stacks, and the container handling vehicle is for operating on a rail grid at an upper level of the framework structure for retrieving storage containers from, and storing storagecontainers in, the storage columns below, and for transporting the storage containers horizontally across the rail system, wherein the vehicle comprises a container lifting assembly for lifting a storage container and a vehicle body, the container lifting assembly comprises a horizontal lifting frame for releasable connection to a storage container, a lifting shaft assembly comprising at least one lifting shaft and four lifting elements, each lifting element has a lower end connected at a corresponding corner section of the lifting frame and an upper end connected to the lifting shaft assembly, such that the lifting frame may be raised or lowered by rotating the lifting shaft; the container handling vehicle comprises at least one sensor for detecting and measuring inclination of the lifting frame relative to a horizontal plane; and the control system is for controlling movements of the at least one container handling vehicle, and the sensor is in communication with a vehicle control module of the container handling vehicle, the vehicle control module is configured to communicate data between the sensor and the control system. A storage system according to clause 18, wherein the vehicle control module is configured to communicate data from the sensor indicating an inclination of the lifting frame outside a predetermined range relative to the horizontal plane, to the control system. A storage system according to clause 18 or 19, wherein the control system is configured to direct the container handling vehicle to a service area of the storage system, or provide an alert to an operator, if data received from the sensor shows that the inclination of the lifting frame is outside a predetermined range relative to the horizontal plane.

Claims

Claims1. A container handling vehicle comprising: a vehicle body (9); and a container lifting assembly (18,5,8) for lifting a storage container; wherein the container lifting assembly comprises a horizontal lifting frame (18) for releasable connection to a storage container (106), a lifting shaft assembly comprising at least one lifting shaft (8a, 8b) and four lifting elements (5), each lifting element (5) having a lower end (14) connected at a corresponding corner section (6) of the lifting frame (18) and an upper end connected to the lifting shaft assembly (8), such that the lifting frame (18) may be raised or lowered by rotating the lifting shaft; wherein the container handling vehicle comprises at least one sensor (7) for detecting and measuring inclination of the lifting frame relative to a horizontal plane, and wherein the container handling vehicle has a lifting element adjustment system comprising a set of actuators (10,11) and an actuator controller (19) in communication with the sensor (7); wherein the set of actuators (10,11) is configured to interact with at least three of the lifting elements to adjust the vertical distance between at least three of the corner sections and the lifting shaft assembly in response to a detected inclination of the lifting frame being outside a predetermined range relative to the horizontal plane, such that the inclination of the lifting frame is returned towards or within the predetermined range relative to the horizontal plane.

2. The container handling vehicle of claim 1, further comprising a vehicle control module, wherein the sensor (7) is in communication with the vehicle control module.

3. The container handling vehicle of any preceding claim, wherein the set of actuators comprises at least three separate actuators, each actuator configured to interact with a respective lifting element.

4. The container handling vehicle of claim 3 wherein the actuators are independently controllable.

5. The container handling vehicle of claim 3 or 4, wherein the lower end (14) of each of the at least three lifting elements (5) is connected to a respective actuator (11).

6. The container handling vehicle of claim 5, wherein the lifting frame (18) comprises a lifting element guide (13) at each of at least three of the corner sections (6), each guide is configured to change the direction of a respective lifting element from a vertical direction to a horizontal direction, and each actuator is coupled to a respective lower end (14) of one of the at least three lifting elements and configured to move the lower end in the horizontal direction.

7. The container handling vehicle of claim 6, wherein the lifting element guide is a guide wheel (13) or shaft having a horizontal centreline.

8. The container handling vehicle of claim 6 or 7, wherein each of the actuators is a linear actuator (11) configured to move the respective lower end between a first position and a second position, wherein the first position is closer to the lifting element guide than the second position.

9. The container handling vehicle of any of claims 1 to 4, wherein the lifting element adjustment system comprises four lifting element interaction rollers (15) arranged in an upper portion of the container handling vehicle, each roller operated by one of the actuators and configured to move a corresponding lifting element away from the vertical such that the vertical distance between any of the corner sections and the lifting shaft assembly may be adjusted.

10. The container handling vehicle of claim 9, wherein each of the rollers is mounted to a pivot arm (12) operated by the respective actuator.

11. The container handling vehicle of any preceding claim, wherein the actuator controller (19) is configured to control the actuators (10,11) based on data received from the sensor (7).

12. The container handling vehicle of any preceding claim, wherein the actuators (10, 11) are configured to continuously keep the respective lifting element (5) under tension.

13. The container handling vehicle of any preceding claim, wherein the lifting elements are lifting bands (5), wires, cables or lines.

14. The container handling vehicle of any preceding claim, wherein the vehicle further comprises a wheel assembly; wherein the wheel assembly comprises a first set of wheels and a second set of wheels enabling movement of the container handling vehicle in two perpendicular directions on a rail grid.

15. The container handling vehicle of any preceding claim, wherein the vehicle is for use with a storage system comprising a framework structure (100), wherein the framework structure (100) comprises multiple storage columns (105), in which storage containers (106) maybe stored on top of one another in vertical stacks (107), and the container handling vehicle is for operating on a rail grid (108) at an upper level of the framework structure for retrieving storage containers (106) from, and storing storage containers in, the storage columns below, and for transporting the storage containers horizontally across the rail system (108).

16. A storage system comprising a framework structure (100) and at least one container handling vehicle (17,17’) according to any preceding claim, wherein the framework structure (100) comprises multiple storage columns (105), in which storage containers (106) maybe stored on top of one another in vertical stacks (107), and the container handling vehicle is for operating on a rail grid (108) at an upper level of the framework structure for retrieving storage containers (106) from, and storing storage containers in, the storage columns below, and for transporting the storage containers horizontally across the rail system (108).

17. The storage system according to claim 16, comprising a control system (500) for controlling movements of the at least one container handling vehicle and wherein the vehicle control module is configured to communicate data between the container handling vehicle and the control system (500).

18. A storage system according to claim 17, wherein the control system (500) is configured to direct the container handling vehicle to a service area of the storage system, or provide an alert to an operator, if data received from the vehicle control module shows that the lifting element adjustment system is unable to return the inclination of the lifting frame to within the predetermined range relative to the horizontal plane.19- A method of controlling a container handling vehicle according to any of claims 1-15 in a storage system, the method comprising:- raising or lowering the lifting frame (18) while simultaneously detecting and measuring any inclination of the lifting frame relative to a horizontal plane by use of the sensor;- detecting an inclination of the lifting frame being outside the predetermined range relative to the horizontal plane; and- operating the set of actuators to adjust the vertical distance between at least one of the corner sections and the lifting shaft assembly, such that the detected inclination of the lifting frame is returned towards or within the predetermined range relative to the horizontal plane.

20. A method according to claim 19, comprising:- detecting an inclination of the lifting frame being outside the predetermined range relative to the horizontal plane after operating the set of actuators; and- directing the container handling vehicle to a service area, or- providing an alert from the control system for an operator.

21. A storage system comprising a framework structure, a control system and at least one container-handling vehicle; wherein the framework structure comprises multiple storage columns, in which storage containers may be stored on top of one another in vertical stacks, and the at least one container handling vehicle is for operating on a rail grid at an upper level of the framework structure for retrieving storage containers from, and storing storage containers in, the storage columns below, and for transporting the storage containers horizontally across the rail system; wherein the vehicle comprises a container lifting assembly for lifting a storage container and a vehicle body; wherein the container lifting assembly comprises a horizontal lifting frame for releasable connection to a storage container, a lifting shaft assembly comprising at least one lifting shaft and four lifting elements,each lifting element has a lower end connected at a corresponding corner section of the lifting frame and an upper end connected to the lifting shaft assembly, such that the lifting frame may be raised or lowered by rotating the lifting shaft; wherein the container handling vehicle comprises at least one sensor for detecting and measuring inclination of the lifting frame relative to a horizontal plane; and the control system is for controlling movements of the at least one container handling vehicle, and the sensor is in communication with a vehicle control module of the container handling vehicle, the vehicle control module is configured to communicate data between the sensor and the control system.

22. The storage system of claim 21, wherein the vehicle control module is configured to communicate data from the sensor to the control system indicating an inclination of the lifting frame outside a predetermined range relative to the horizontal plane.

23. The storage system of claim 21 or 22, wherein the control system is configured to direct the container handling vehicle to a service area of the storage system, or provide an alert to an operator, if data received from the sensor shows that the inclination of the lifting frame is outside a predetermined range relative to the horizontal plane.

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