ROBOT TO PICK UP AND TRANSPORT OBJECTS, CORRESPONDING USE AND METHOD

Abstract

The present invention relates to a robot (2) configured to pick up and transport items; wherein the robot (2) comprises a pick up unit (10), wherein the pick up unit (10) comprises a pick up device (110) configured to pick up and release items, wherein the robot (2) is configured to move the pick up device (110) along a first direction, rotate the pick up device (110) around a first axis, and extend and retract the pick up device (110) along a second direction different from the first direction; wherein the robot (2) further comprises a shelf unit (8) configured to temporarily store items, wherein the shelf unit (8) comprises a rotatable portion (80) and a support structure (84), wherein the rotatable portion (80) is rotatable with respect to the support structure (84). The present invention also relates to a use of the robot and to a corresponding method.

Claims

1-15. (canceled)

16. A robot (2) configured to pick up and transport items; wherein the robot (2) comprises a pick up unit (10), wherein the pick up unit (10) comprises a pick up device (110) configured to pick up and release items, wherein the robot (2) is configured to move the pick up device (110) along a first direction, rotate the pick up device (110) around a first axis, and extend and retract the pick up device (110) along a second direction different from the first direction; wherein the robot (2) further comprises a shelf unit (8) configured to temporarily store items, wherein the shelf unit (8) comprises a rotatable portion (80) and a support structure (84), wherein the rotatable portion (80) is rotatable with respect to the support structure (84); wherein the rotatable portion (80) comprises a plurality of case boards (82) for supporting the items; characterized in that the support structure (84) comprises a shelf housing that houses the case boards (82).

17. The robot (2) according to claim 16, wherein the rotatable portion (80) of the shelf unit (8) is rotatable around a shelf unit rotation axis that is parallel to the first axis.

18. The robot (2) according to claim 16, wherein the support structure (84) comprises a top support structure (846) located above the rotatable portion (80).

19. The robot (2) according to claim 18, wherein the support structure (84) further comprises a bottom support structure (842), wherein the rotatable portion (80) is located above the bottom support structure (842), and support bars (844) connecting the top support structure (846) and the bottom support structure (842).

20. The robot (2) according to claim 16, wherein the rotatable portion (80) is rotatable with respect to the support structure (84) by at least 10°, preferably at least 20°, further preferably at least 30°; and wherein the rotatable portion (80) is rotatable with respect to the support structure (84) by not more than 100°, preferably by not more than 70°, further preferably by not more than 40°; and wherein the robot (2) comprises a rotation delimiter for delimiting the rotation of the rotatable portion.

21. The robot (2) according to claim 16, wherein the robot (2) comprises at least one bar (102), and preferably a plurality of bars (102), such as two bars (102), disposed along the first direction, and wherein the pick up device (110) is movable along the at least one bar (102); wherein the at least one bar (102) is telescopable between a retracted and an extended configuration.

22. The robot (2) according to claim 16, wherein the pick up unit (10) further comprises a pick up unit housing (120) that houses the pick up device (110).

23. A method to pick up and transport items, the method using a robot (2) configured to pick up and transport items; wherein the robot (2) comprises a pick up unit (10), wherein the pick up unit (10) comprises a pick up device (110) configured to pick up and release items, wherein the robot (2) is configured to move the pick up device (110) along a first direction, rotate the pick up device (110) around a first axis, and extend and retract the pick up device (110) along a second direction different from the first direction; wherein the robot (2) further comprises a shelf unit (8) configured to temporarily store items, wherein the shelf unit (8) comprises a rotatable portion (80) and a support structure (84), wherein the rotatable portion (80) is rotatable with respect to the support structure (84); wherein the rotatable portion (80) of the shelf unit (8) is rotatable around a shelf unit rotation axis that is parallel to the first axis, wherein the connection between the first axis and the shelf unit rotation axis defines a connection line; wherein the rotatable portion (80) comprises a plurality of case boards (82) for supporting the items; the method comprising the robot (2) travelling to a first shelf; the robot (2) picking up a first item by means of the pick up unit (10); the robot (2) transferring the first item to the shelf unit (8) after the robot (2) picking up the first item; the robot (2) picking up a second item by means of the pick up unit (10); and the robot (2) transferring the second item to the shelf unit (8) after the robot (2) picking up the second item; wherein in the step of the robot (2) transferring the first item to the shelf unit (8), the first item is placed on a case board (82), and in the step of the robot transferring the second item to the shelf unit (8), the second item is placed on said case board (82), while the first item is located on said shelf board (82) wherein in the step of the robot (2) transferring the first item to the shelf unit (8), the pick up device (110) assumes a first pick up device angle configuration with respect to the connection line and the rotatable portion (80) assumes a first shelf angle configuration with respect to the connection line, and in the step of the robot (2) transferring the second item to the shelf unit (8), the pick up device (110) assumes a second pick up device angle configuration with respect to the connection line and the rotatable portion (80) assumes a second shelf angle configuration with respect to the connection line, wherein the second pick up device angle configuration differs from the first pick up device angle configuration by a pick up device difference angle, the second shelf angle configuration differs from the first shelf angle configuration by a shelf difference angle, and wherein the pick up device difference angle equals the shelf difference angle.

24. The method according to claim 23, wherein the method comprises the pick up device (110) being rotated around the first axis after the robot (2) picking up the first item and before the robot (2) transferring the first item to the shelf unit (8).

25. The method according to claim 23, wherein the robot (2) comprises the features of claim 17 and wherein the connection between the first axis and the shelf unit rotation axis defines a connection line; wherein in the step of the robot (2) transferring the first item to the shelf unit (8), the pick up device (110) extends along the second direction, wherein, in this step, the second direction is different from the connection line by a rotation angle, and further wherein in the step of the robot (2) transferring the first item to the shelf unit (8), the rotatable portion (80) of the shelf unit (8) is rotated from a rest position of the rotatable portion (80) by the rotation angle.

26. The method according to claim 25, wherein the first item and the second item are regularly shaped objects and wherein the second item is placed on said case board (82) parallel to the first item.

27. The method according to claim 24, wherein the method further comprises the robot (2) picking up a third item by means of the pick up unit (10); and the robot (2) transferring the third item to the shelf unit (8) after the robot (2) picking up the second item; wherein in the step of the robot transferring the third item to the shelf unit (8), the third item is placed on said case board (82), while the first item and the second item are located on said shelf board (82).

28. The method according to claim 27, wherein the third item is a regularly shaped object and wherein the third item is placed on said case board (82) parallel to the first item and to the second item.

Description

[0120] Embodiments of the present invention will now be described with reference to the accompanying drawings, which are intended to exemplify, but not to limit, the scope of the present invention.

[0121] FIG. 1 depicts a side view of a robot according to embodiments of the present invention;

[0122] FIG. 2 depicts a perspective view of sections of a robot according to embodiments of the present invention;

[0123] FIG. 3 depicts a top cross-sectional view of sections of a robot according to embodiments of the present invention;

[0124] FIG. 4 depicts a shelf unit of a robot according to embodiments of the present invention;

[0125] FIG. 5 depicts another side view of the robot of FIG. 1;

[0126] FIG. 6 depicts a section of a robot according to embodiments of the present invention;

[0127] FIGS. 7a and 7b illustrate a pick up mechanism of embodiments of the present invention;

[0128] FIGS. 8a and 8b also illustrate a pick up mechanism of embodiments of the present invention;

[0129] FIGS. 9 and 10 schematically illustrate rationales for loading a shelf unit;

[0130] FIG. 11 depicts a side view of a robot according to another embodiment of the present invention; and

[0131] FIG. 12 depicts a perspective view of the robot of FIG. 11.

[0132] FIG. 1 depicts an embodiment of a robot 2 according to embodiments of the present invention. The robot 2 is configured to travel freely. That is, the robot 2 is configured to reach any location in an environment where the robot 2 operates in. That is, the robot 2 may be configured not to follow predetermined paths in its environment, but to travel freely.

[0133] The robot 2 may comprise an energy storage unit (such as a battery unit), a drive unit 6, as well as one or more wheels 46.

[0134] The robot 2 may be configured to pick up and transport objects or items. In general terms, the robot 2 may comprise different units. In particular, the robot 2 may comprise a pick up unit 10 and a shelf unit 8. The pick up unit 10 is configured to pick up items and the shelf unit 8 may be configured to intermediately store items. That is, the robot 2 may pick up an item by means of the pick up unit 10 and may store the item in shelf unit 8, which shelf unit 8 may therefore also be referred to as intermediate storage unit. In particular, the shelf unit 8 may comprise a plurality of case boards 82 positioned in different vertical positions. Whenever reference herein is made to terms like vertical and horizontal (or top and bottom), these terms are understood in an in-use configuration, where the robot 2 is in its intended configuration having its, e.g., wheels contacting the ground.

[0135] The pick up unit 10 is configured to pick up items. Further details of an exemplary pick up unit 10 are depicted in FIG. 2, which FIG. 2 depicts an embodiment of a robot 2 (or parts thereof), where the shelf unit 8 has been omitted for clarity of illustration. The pick up unit 10 comprises a pick up device 110 adapted to grip objects. Furthermore, the pick up unit 10 is configured to move the pick up device 110 in a vertical direction, to rotate it around a vertical axis and to move it in a horizontal direction.

[0136] The pick up unit 10 may also comprise a housing 120. This housing is only partially depicted in FIG. 2, to expose the further components of the pick up unit 10, but is visible in FIG. 1. The housing may delimit the pick up unit 10 and may separate other components (and in particular the pick up device 110) from the outside. This may render the robot 2 safer, which may be particularly advantageous when the robot 2 is operated in an environment where also humans are present. In particular, the pick up device 110 may only extend from the inside of the housing 120 when gripping an object, but otherwise (and in particular, while the robot 2 is travelling) be positioned inside the housing 120.

[0137] Again with primary reference to FIG. 2, the pick up 10 unit comprises at least one bar 102, and preferably two bars 102, and the pick up device 110 is configured to move along this at least one bar 102 in a vertical direction. Thus, the pick up device 110 may assume different vertical positions and may thereby reach different case boards of an external shelf where items are stored in and may also reach different case boards 82 of the shelf unit 8 of the robot 2. In some embodiments, the at least one bar 102 may also be telescopable between at least a retracted and an extended configuration. This may allow the robot 2 to pick up objects at greater heights, while still allowing the robot 2 to travel underneath low clearances, and may therefore improve the usability of the robot 2. The pick up unit 10 may also comprise one or more connector members 122 connecting the bars 102 (e.g., for stability reasons) and a connection bar 104 connecting the bars 102 at their top end.

[0138] As regards the rotation around a vertical axis, the pick up unit 10 comprises a pick up unit support plate 124, which is rotatable with respect to a base plate 4 of the robot 2. The at least one bar 102 is supported by the pick up unit support plate 124. Thus, rotation of the pick up unit support plate 124 also leads to rotation of the pick up device 110. By means of such a mechanism, the pick up device 110 may be rotatable with respect to a vertical axis.

[0139] Further details of the pick up device 110 will now be described with reference to FIGS. 7a to 8b. There may be provided a sensor assembly 1102 on the pick up device 110 adapted to sense the exact location of an object 1002 to be picked up. Typically, such a sensor assembly 1002 could comprise at least one camera. The camera may be, for example, a 3D camera or a camera including a depth sensor. By means of such a sensor assembly 1102, the exact location of the object 1002 to be picked up may be sensed. The pick up device 110 may be primarily adapted to pick up regularly shaped objects 1002, such as boxes, books and/or DVDs. As depicted, e.g., in FIGS. 7b and 8b, which are enlarged views of a section of FIGS. 7a and 8a, respectively, the pick up device 110 may comprise a support plate 1104 and a pulling assembly 1106. The support plate 1104 is disposed substantially horizontally. According to one embodiment, it may be extended in a horizontal direction. Thus, it may be placed under the rack of the shelf where the object 1002 to be picked up is located. It may also be placed on level with the rack of the shelf where the object 1002 to be picked up is located and directly adjacent to this rack. The pulling assembly 1106 comprises a substantially horizontal portion 11062 and a vertical extension 11064 on the distal end of the horizontal portion 11062. The vertical extension 11064 extends downwards from the horizontal portion 11062. The horizontal portion 11062 is extendable and retractable between extended and retracted configurations. Furthermore, the vertical distance between the support plate 1104 and the pulling assembly 1106 is adjustable. To pick up object 1002, the exact location of the object 1002 is sensed by means of sensor assembly 1102, the support plate 1104 is moved to a location under the rack the object 1002 is located on or directly adjacent to said rack. The pulling assembly 1006 is positioned on a vertical position allowing the pulling assembly 1006 to be extended further than the distal end of the object 1002 and the pulling assembly 1006 is extended in such a way (see FIGS. 7a and 7b). The pulling assembly 1006 is then lowered to a point where the vertical extension 11064 may abut the distal end of the object 1002 and the pulling assembly 1106 is retracted (see FIGS. 8a and 8b). This causes the object 1002 to slide onto support plate 1104. The pick up device 110 including the support plate 1104 and the pulling assembly 1106 may be retracted, such that the pick up assembly 110 together with the object 1002 is retracted to a location, e.g., in between the bars 102. Thus an object or item 1002 may be picked up by means of the pick up device 110.

[0140] It will be understood that the pick up device 110 may be used in a similar way to pick up objects from the shelf unit 8 of the robot 2. Furthermore, it will also be understood that the objects may be placed from the pick up device 110 to the shelf unit 8 of the robot 2 (or to an external shelf) by an essentially correspondingly reversed method.

[0141] Further features of the robot 2, and particularly the pick up unit 10 and the exact pick up mechanism are also described in EP16151220, filed 14, Jan. 2016, which is incorporated herein by reference in its entirety.

[0142] By the described features, it is possible that the robot 2 travels to an external shelf unit, and picks up an object 1002. To do so, the robot 2 is positioned at the correct location, the pick up device 110 of the pick up unit 100 travels along the bar(s) 102 to the correct height, and the object 1002 to be picked up is picked up by the pick up device 110. To do so, the pick up device 110 extends, picks up the object 1002 and retracts back into the remainder of the robot 2. The object 1002 is then located at the pick up device 110. As long as the object 1002 is located at the pick up device 110, it may be impossible for the robot 2 to pick up another object.

[0143] If only one object 1002 is to be picked up and to be transported to a destiny location, this may be sufficient. In such a case, the robot 2 may simply travel to the destiny location while the object 1002 is located at the pick up device 110. However, in other scenarios, it may be desirable that the robot 2 transports more than one object 1002 at once. For example, when used in a fulfillment center, it may be more efficient for the robot to pick up a plurality of objects and to transport them to the destiny location (e.g., for shipping). In such scenarios, the robot 2 may put objects into the shelf unit 8, and pick up a plurality of objects.

[0144] In that regard, it is desirable that the robot 2 makes efficient usage of the storage space, i.e., of its shelf unit 8. E.g., to improve the storage efficiency, the shelf unit 8 of the robot 2 comprises at least a section or portion 80 that is rotatable. More particularly, the section 80 may be rotatable around a vertical axis.

[0145] A rationale for a rotatable portion of the shelf unit 8 is provided with reference to FIGS. 9 and 10. FIG. 9 depicts a very schematic top view of a portion of the pick up unit 10, a case board 82 of the shelf unit 8 and an object 1002 to be transferred from the pick up unit 10 to the shelf unit 8. Furthermore, arrow A indicates the direction of movement of the pick up device 100. As discussed, the pick up unit 10 is configured to rotate the pick up device 100 around a vertical axis. This is why the arrow A may rotate (cf. FIGS. 9 (a) and (c)). Typically, when transferring the object 1002 from the pick up unit 10 to a case board 82 of a shelf unit 8, the pick up unit 10 assumes a configuration where the pick up device 110 extends substantially perpendicularly into the shelf unit 8 (see FIG. 9 (b)). For sake of brevity and clarity of illustration, not all reference numerals are included in all of the sub-figures of FIG. 9. However, as is depicted in FIGS. 9 (c) and 9 (d), the robot 2 may (theoretically) assume other configurations than the perpendicular one to transfer objects 1002 from the pick up unit 10 to the shelf unit 8, thereby arriving at objects 1002 positioned askew on the case board 82.

[0146] In the described embodiment, in addition to the pick up device 110, also a portion of the shelf unit 8, and in particular the case boards 82, are rotatable, as depicted in FIG. 10. By co-rotating the pick up unit 10 and the shelf unit 8 (see FIG. 10), one may position different objects 1002, 1002′ onto the case board 82 of the shelf unit 8. While in FIG. 10, it is depicted that two objects 1002, 1002′ are positioned on one case board 82, the skilled person will understand that this embodiment also allows more than two objects 1002, 1002′ to be positioned on one case board 82 (depending on the sizes of the objects and the size of the case board 82).

[0147] Having a section of the shelf unit 8 being rotatable thus significantly increases the storage capacity and storage efficiency of the robot 2. The robot 2 of this embodiment is therefore able to simultaneously transport much more objects 1002 than would have been possible with prior art solutions. Thus, the transport efficiency is increased, and the overall energy consumption per transported object reduced—as the robot 2 has to travel less often than would be necessary in case the shelf unit 8 did not have a rotatable portion 80.

[0148] In certain embodiments, the rotation of the pick up unit 10 and the rotatable portion 80 of the shelf unit 8 is the same, i.e., both entities are rotated by the same angle. This is also depicted in FIG. 10. In particular, this rotation may be measured with respect to a line connecting the rotation axis of the pick up unit 10 and the rotation axis of the rotatable portion 80 of the shelf unit 8. As discussed, the pick up device 100 may move along arrow A, which, in the configuration depicted in FIG. 10 (a) is at an acute angle with respect to the line connecting the discussed rotation axes. Also the rotatable portion of the shelf unit is rotated by this angle with respect to its rest position, e.g., a position being symmetrical with respect to the connection line of the discussed axes. This may allow for a particularly simple and space-saving storing of the items 1002. It is noted that the same rationale is present throughout FIGS. 10 (a) to (d).

[0149] FIG. 3 depicts a schematic cross sectional view of the robot 2 depicted in FIG. 1 along line A-A. Again, the pick up unit 10 is depicted by means of a schematic circle 10, and a case board 82 of the shelf unit 8 is depicted. In the embodiment depicted in FIG. 3, exemplary dimensions of the robot 2 or section of the robot 2 are included. The robot 2 may have a width of 60 cm. In the depicted embodiment and configuration, the pick up device 110 of the pick up unit 10 is at an angle A of 17° from a configuration with full perpendicularity to the shelf unit 8 or to the case board 82. The case board 82 is also rotated by 17° from its rest position. In the depicted embodiments, this leads to an offset O of 13.7 cm. It will be understood that the robot 2 may also rotate the pick up device 110 and the case board 82 in the opposite direction, i.e., to −17°, leading to an offset of −13.7 cm. Thus, the robot depicted in FIG. 3 may put objects onto a case board 82 of the shelf unit in a range of 27.4 cm, which may considerably increase the storage capacity of the depicted robot 2 vis-à-vis robots where the shelf unit 8 is not rotatable. One advantage vis-à-vis non-rotatable shelfs is that the depicted embodiment allows storing items parallel to one another. Thus, less storage space is lost between the items.

[0150] Further details of the robot 2 and the shelf unit 8 will now be described with primary reference to FIGS. 4 and 5. FIG. 5 depicts another side view of the robot 2, and FIG. 4 depicts a perspective view of the shelf unit 8. The shelf unit 8 comprises different sections or portions. More particularly, the shelf unit 8 comprises a support structure or support frame 84 and a rotatable portion 80. The rotatable portion 80 comprises the case boards 82 (hidden in FIGS. 4 and 5). The rotatable portion 80 is rotatable with respect to the support frame 84. In the depicted embodiments, the support frame 84, which may also be referred to as the support structure 84, comprises a bottom support structure 842, a top support structure 846, and supporting bars 844 connecting the bottom support structure 842 and the top support structure 846. The support structure or support frame 84 is fixed (i.e., not rotatable) and supports the remainder of the shelf unit 8, i.e., the rotatable portion 80. In the depicted embodiment, the rotatable portion 80 is located vertically between the bottom support structure 842 and the top support structure 846. The top support structure 846 rotatably supports the rotatable portion 80 from above. The rotatable portion 80 of the shelf unit 8 may comprise the case boards 82 and a housing surrounding the case boards 82 and/or delimiting the case boards 82 from the outside. This may increase the safety of the robot 2, as only the housing is exposed to the outside, and not the case boards 82 which may have edges and/or items transported on the case boards 82. However, it is noted that in other embodiments, the housing may also be non-rotatable with respect to the support structure 84. In such a case, the rotatable portion including the case boards would also be rotatable vis-à-vis the housing.

[0151] Further details of a rotation mechanism for rotating the portion 80 are depicted in FIG. 6. This Fig. depicts a top view of the bottom support structure 842. The rotation mechanism comprises a ball bearing 86, such as a 4-point ball bearing (which may be obtained by Franke GmbH, Aalen, Germany), with an inner ring 862 and an outer ring 864, the outer ring 864 being rotatable with respect to the inner ring 862. The inner ring 862 may be fixed to the bottom support structure 842 and the outer ring 864 may be movable (i.e., rotatable) with respect to the bottom support structure 842. The outer ring 864 comprises a geared circumference. The rotation mechanism further comprises a drive belt 866, which may be toothed and which may gear into the geared circumference of the outer ring 864. The rotation mechanism also comprises a driver or pinion 868 for driving the drive belt 866 and thus the outer ring 864. The pinion 868 itself is driven by a motor (which is also part of the rotation mechanism), which motor may be a step motor. Thus, the outer ring 864 may rotate with respect to the inner ring 862.

[0152] The rotatable portion 80 of the shelf unit 8 is mounted (i.e., fixed) to the outer ring 864, and is thus rotatable with respect to the inner ring 862 and with respect to the bottom support structure 842. The connection between the rotatable portion 80 of the shelf unit 8 and the inner ring 862 may be provided by means of a drive pin. Furthermore, there may be provided a rotation delimiter limiting the movement of the drive pin (and thus, also the rotation range of the rotation mechanism and thus the rotatable portion). The rotation delimiter may comprise abutment structures to which the drive pin abuts. As an example, the rotation delimiter may be realized as a circular structure having an opening allowing the drive pin to move in the opening. Thus, the drive pin, and hence the rotatable portion 80, may be delimited in their rotation. As also depicted in FIG. 3, exemplary values for the rotation limitation include 20° to 40° (i.e., 10° to 20° in both directions), such as 34° (i.e., 17° in both directions).

[0153] In the above figure description, the present invention has been described with reference to an embodiment of a robot 2 having an exemplary pick up unit 10. However, it should be understood that the hitherto described pick up unit 10 is merely exemplary and that other embodiments of the present invention are also possible. This is further illustrated in FIGS. 11 and 12. In these Figures, features like the ones discussed above are identified by like reference numerals (and the description of such features may be omitted for sake of brevity of description).

[0154] While the shelf unit 80 in the embodiment depicted in FIGS. 11 and 12 may be like the one described above, the pick up unit 10 may be different. More particularly, FIG. 1 depicts a pick up unit 10 of a “tower type”, where the pick up unit 10 resembles a tower that is supported on its lower end by a base plate 4 of the robot 2.

[0155] To the contrary, the pick up unit 10 of the embodiment of FIGS. 11 and 12 is not supported from below. Instead, the pick up unit 10 is a “suspension type” pick up unit 10. This pick up unit is not supported from below, but is suspended. In simple terms, the robot 2 of FIGS. 11 and 12 also comprises at least one vertical bar 102 (such as two bars 102) and a pick up section 105 which may travel along the bar(s) 102 in the vertical direction. The pick up section 105 comprises a pick up device 110, which may be the pick up device 110 as described above in conjunction with FIGS. 7a to 8b, for example. In the embodiment of FIGS. 11 and 12, the pick up section 105 also comprises a housing 106, housing the pick up device 110 and delimiting it from the outside, e.g., to render the robot 2 safer. Furthermore, in the embodiment depicted in FIGS. 11 and 12, the pick up device 10 also comprises a top plate 104, and the pick up section 105 is rotatably mounted to top plate 104. The rotatable connection between the two may be similar to the rotatable connection between bottom support unit 842 and the rotatable portion 80 of the shelf unit 8 discussed above in conjunction with FIG. 6.

[0156] It will therefore be understood that the suspended pick up unit 10 of FIG. 11 is movable in the vertical direction (by being movable along the bar(s) 102). Furthermore, as before, the bar(s) may also be telescopable to allow the robot 2 to reach objects in greater heights, while still allowing the robot 2 to travel under low clearances.

[0157] Furthermore, by means of the rotation between top plate 104 and pick up section 105, the pick up device 110 is also rotatable. As discussed above, the pick up device is also extendible and retractable in a horizontal direction. Thus, the pick up unit 10 of FIG. 11 also allows objects in different locations to be picked up by the robot 2.

[0158] Also in the embodiment depicted in FIGS. 11 and 12, the shelf unit 8 comprises a section 80 that is rotatable with respect to a shelf support structure. The rotatable section or portion 80 again comprises the case boards 82. As discussed above, this allows the storage space in the shelf unit 8 to be used more efficiently.

[0159] One further advantage of the robot 2 depicted in FIGS. 11 and 12, i.e., the suspension type robot 2, is that the suspension type pick up unit 10 is not supported from below, i.e., there is no further portion of the robot 2 below the pick up unit 10. Thus, the pick up unit may reach objects that are located very close to the ground or, in fact, on the ground level, thereby increasing the usability of the robot 2.

[0160] Further features of the robot 2 depicted in FIGS. 11 and 12, and particularly the pick up unit 10 and the exact pick up mechanism are also described in EP17000402, filed 11, Mar. 2017, which is incorporates herein by reference in its entirety.

[0161] Whenever a relative term, such as “about”, “substantially” or “approximately” is used in this specification, such a term should also be construed to also include the exact term. That is, e.g., “substantially straight” should be construed to also include “(exactly) straight”.

[0162] Whenever steps were recited in the above or also in the appended claims, it should be noted that the order in which the steps are recited in this text may be accidental. That is, unless otherwise specified or unless clear to the skilled person, the order in which steps are recited may be accidental. That is, when the present document states, e.g., that a method comprises steps (A) and (B), this does not necessarily mean that step (A) precedes step (B), but it is also possible that step (A) is performed (at least partly) simultaneously with step (B) or that step (B) precedes step (A). Furthermore, when a step (X) is said to precede another step (Z), this does not imply that there is no step between steps (X) and (Z). That is, step (X) preceding step (Z) encompasses the situation that step (X) is performed directly before step (Z), but also the situation that (X) is performed before one or more steps (Y1), . . . , followed by step (Z). Corresponding considerations apply when terms like “after” or “before” are used.

[0163] While in the above, a preferred embodiment has been described with reference to the accompanying drawings, the skilled person will understand that this embodiment was provided for illustrative purpose only and should by no means be construed to limit the scope of the present invention, which is defined by the claims.