WO2020239185A1

WO2020239185A1 - Vertical farming robot

Info

Publication number: WO2020239185A1
Application number: PCT/DK2020/050155
Authority: WO
Inventors: Aage STARUP
Original assignee: Invenstar Aps
Priority date: 2019-05-28
Filing date: 2020-05-28
Publication date: 2020-12-03

Abstract

A vertical farming robot, comprising one or more stacks of trays, each tray accommo- dating growth medium, where each tray is arranged one over the other on separate bearing means, and where a lifting bridge is arranged adjacent the one or more stacks of trays, where said lifting bridge is elevated or lowered to a desired position by a lift- ing mechanism, where said lifting bridge comprises engagement means for engaging a desired tray and pulling said tray from the bearing means onto the lifting bridge and/or pushing said tray back on said bearing means, and where a desired tray may be low- ered and transferred onto a conveyor, which conveyor transports the tray to an outside location from the vertical farming robot, or where said conveyor transports a tray from a location outside the vertical farming robot and into a position where the tray is pulled onto the lifting bridge.

Description

Vertical farming robot

Field of the Invention

The present invention relates to a vertical farming robot and a method of using such a robot.

Background of the Invention

It is well-known to cultivate plants, crops and flowers either in the open land or in greenhouses.

When farming in the open land there are a number of factors which are not controlla ble by the farmer, such as the weather, wind, temperature etc. whereas it is possible to a certain degree to control the level of suitability of the growth media, i.e. to fertilize and cultivate the soil in which the crop is to be cultivated. Likewise, it is possible to a certain degree to control the humidity and moisture in dry periods but in wet spells it is impossible to hinder the moisture content in the soil to reach detrimental levels with the negative effect it may have on the crop to be cultivated. For these purposes a num ber of crops are cultivated in greenhouses where it is possible to substantially control all parameters of the growth process such as temperature, moisture, lighting and sup ply of water and fertilizer to the plants.

Greenhouses, however, are a very expensive manner in which to grow crops in that the construction cost of a greenhouse is substantial as are the running costs such as heating, cooling, ventilation and maintenance of the greenhouse also a substantial cost which has to be regained from the sale of the crops cultivated inside the greenhouse. With an ever increasing need for cheaper and better crops it is necessary to look for alternative ways in order to bring down the cost of producing crops of an increased quality. Object of the Invention

The invention provides such an alternative in the form of a vertical farming robot, comprising one or more stacks of trays, each tray accommodating growth medium, where each tray is arranged one over the other on separate bearing means, and where a lifting bridge is arranged adjacent the one or more stacks of trays, where said lifting bridge is elevated or lowered to a desired position by a lifting mechanism, where said lifting bridge comprises engagement means for engaging a desired tray and pulling said tray from the bearing means onto the lifting bridge and/or pushing said tray back on said bearing means, and where a desired tray may be lowered and transferred onto a conveyor, which conveyor transports the tray to an outside location from the vertical farming robot, or where said conveyor transports a tray from a location outside the vertical farming robot and into a position where the tray is pulled onto the lifting bridge.

Description of the Invention

One of the problems with greenhouses is that the propagation of plants, the growing of crops is two-dimensional such that the crops will be spread over a relatively large area requiring a substantial greenhouse in order to accommodate the number of square me ters required for growing the desired amount of crops. By arranging the growing trays one over another it is possible to have a larger growing area per area unit land which the vertical farming robot occupies. On the other hand it will be necessary to be able to retrieve, cultivate and harvest each tray at each level. For this purpose the invention provides a lifting bridge which has means to be positioned adjacent any tray in the stack of trays and retrieve a tray such that the tray may be brought down to a level where it is possible to manage and inspect or work on the crops being cultivated in each tray.

Each tray may be a standard tray as already used in the greenhouse industry such that much of the equipment already present in the industry may be reused with the present invention.

In principle any number of trays may be arranged on top of each other in separate bearings such that the lifting bridge may engage a tray, pull it on the lifting bridge, bring it down to a level where it is possible to manually inspect and work on the tray and then bring the tray back in the desired position again.

Therefore, by being able control the lifting bridge it is possible to retrieve any tray in any stack and either carry out the tasks which the lifting bridge is able to carry out either by itself or from a remote control or retrieve the tray and bring it to the outside of the vertical farming robot. By being able to retrieve any tray from any stack from which the lifting robot is able to engage trays it is possible to bring them to the outside such that any manual work may be carried out on the tray before the tray is replaced inside the vertical farming robot. This of course saves a lot of space in that the aggre gated growing area is relatively huge inside the robot due to the stacking of the trays one on top of the other whereas the lifting robot and its facility to be able to retrieve a tray and move and convey it to the outside of the farming robot makes it possible to attend to the trays in a completely normal manner as any tray in a normal greenhouse would be attended to. In order to be able to retrieve and arrange the trays on the bear ing means in the stack of trays the vertical farming robot and particularly the lifting bridge is provided with engagement means. The engagement means on the lifting bridge is a conveyor having an endless conveyor belt arranged for rotation, and where the conveyor is provided with engagement fins extending from the surface of the con- veyor belt, such that in use the engagement fins may be brought into engagement with the underside of a tray in order to move the tray, either away from the bearing means onto the lifting bridge or push the tray from the lifting bridge onto the bearing means.

The engagement means on the conveyor makes it possible by controlling the rotation direction of the conveyor to retrieve trays from either side of the lifting bridge and positioning these trays on the lifting bridge for any treatment that is desired. Further more, the conveyor may be extended from the lifting bridge to a stack which is further away than the immediate stack of trays, and in this manner it may be possible to have a plurality of stacks arranged on either side of the lifting bridge due to the facility of the conveyor belt being able to extend a region where it is possible for the engagement means of the lifting bridge to engage the trays in any stack. In a further advantageous embodiment each tray has one or more inner trays, which inner tray(s) is/are removably arranged in the tray, and where the tray at least along a lower edge is provided with an indentation. As it is desirable to handle the plants and growing medium in any tray the tray which is basically a frame may be provided with a removable inner tray such that depending on the crop which it is desirable to propagate in the trays the growth medium may be selected according to that particular plant without having to have a full tray or a num ber of trays propagating the same crop. A further advantage is also that it may be easi- er to handle smaller sections of a tray by having a plurality of inner trays arranged in each tray such that when the tray is brought to the outside of the vertical farming robot the inner trays may be manually handled without use of very heavy equipment.

The indentation provided in the lower side of the tray is provided in order for the load- ing and unloading conveyor to be able to engage the inner tray and retrieve it without engaging the tray.

In embodiments of the invention where inner trays are used the trays serve as carrying frames for these inner trays. When a desired inner tray is retrieved and transported to the outside of the vertical farming robot it is advantageous to only retrieve the inner tray and not the entire tray and inner tray construction such that another inner tray may be placed on a tray and be put back in the stack of trays. It is maybe in situations where the crop on the inner tray has reached a stage where further processing outside the vertical farming robot is to take place or any other reason why it is desirable to carry out tasks related to the inner tray.

In this manner the slot in the vertical farming robot occupied by that inner tray may be used for a different inner tray. In a further advantageous embodiment the trays are in the shape of frames such that the frames will be able to accommodate for example inner trays or other forms of growth medium and where each tray has an underside or lattice work constituting an underside, and where lights are arranged on said underside, for providing light to plants growing in the tray below. As one of the most important factors in propagation of plants is the availability of light each underside of each tray is provided with lights such that the lights will shine downwards towards the surface of a tray arranged underneath the first tray. In this manner it is possible to control the light very precisely on each tray and to control the entire growth sequence to which the plants to be grown in the trays is to be exposed.

As the lights will be arranged immediately above the tray below, the light diffusion is of course important, but the waste of light which normally is the problem in normal greenhouses, is not present in that the distance between the lights and the surface of the tray may be adjusted to be as short as possible.

As will be explained further below with reference to a particular embodiment of the invention the distance between the lights and the surface of the growth media in the tray below will typically be between 25 and 35 cm i.e. indicating a very close stacking of the trays one above the other in a stack. As already very briefly touched upon above, the invention in a further advantageous embodiment foresees that two stacks of trays are arranged with a horizontal distance between them allowing the lifting bridge to operate in the space between the two stacks, and where a housing is provided en- closing the two stacks and the space between the two stacks, where said housing has a closable opening, said opening allowing trays to be retrieved from and inserted into one of the stacks of the vertical farming robot.

By closing such an arrangement inside a housing it becomes possible to fully control the environment inside the housing and thereby provide optimum growth conditions at all times for the plants being propagated inside the housing in the vertical farming robot. Furthermore, due to the very close spacing of the trays vertically, the area en closed by the housing is very limited whereas heightwise the housing may be quite substantial accommodating a very large number of trays and therefore effectively farming a relatively large area compared to the area of the housing. The distance pro vided horizontally between two stacks should be such that the lifting bridge may pass vertically between the stacks in the horizontal space provided between adjacent stacks. When having an enclosed housing enclosing the trays of the present invention, it is possible to fully control the interior climate.

An important aspect of the invention is the use a relatively large trays, typically 2 by 6 meters, which when provided with a moist growth medium and plants will be relative ly heavy. For this purpose, the invention in a further advantageous embodiment is constructed such that each tray has a carrying frame structure comprising shorter lat eral beams substantially spanning the width of a tray and longer longitudinal beams, substantially spanning the length of the tray, such that in use either end of the longitu- dinal beams rests on the bearing means, where the longitudinal beams in a middle section have a reinforced section, and where the reinforced section is either an integral part of said longitudinal beam, or is connected to the longitudinal beam in a manner allowing loads from inner trays to be transmitted to the bearing means. Advantageously as disclosed in a further embodiment the reinforced section extends above the longitudinal beam, and where in use an inner tray comprising growth medi um rests on said reinforced section.

These embodiments provide stiffness in the trays (carrying structure) such that the lifting bridge, when handling the trays will always be positioned correctly. When the relatively long longitudinal beams are loaded they will tend to bend slightly (under the load). By providing the middle section a number of advantages are obtained. Firstly, the very stiff frame does not tend to bend under the load and therefore retains the large growth trays and trays substantially in their original shape. It also makes it possible to handle very large trays as the support of the trays is not in the ends of the trays, but rather displaced to the ends of the middle section. In reality the ends of the growth trays will be free of the ends of the trays. As the trays’ carrying engagement with the growth trays are placed inwards from the ends of the growth trays, the load distribu tion in the structure of the growth trays is also improved, according to the usual rules of supporting a beam on more supports Also the engagement by the lifting bridge and the trays is facilitated in that due to the straightness of the trays, the lifting bridge’s engagement means will engage the trays at exactly the same level every time, and will not have to be manually adjusted according to the particular load/bending of a particu lar tray. Description of the Drawing

The invention will now be described with reference to the accompanying drawings wherein Figure 1 illustrates an embodiment of a vertical farming robot according to the invention

Figure 2 illustrates the invention where the outer cladding of the housing has been removed in order to reveal the inner structure Figure 3 illustrates the invention with a further conveyor

Figure 4 A illustrates a plane view of the lifting bridge

Figure 4B illustrates a symmetric view of the lifting bridge

Figure 5 illustrates the lifting bridge provided with a spraying arrangement Figure 6 illustrates the invention where the lifting bridge is provided with a longitudinal rail

Figure 7 schematically illustrates a side view of a tray

Figure 8 illustrates the construction fig. 1 stripped of cladding

Figure 9 illustrates a conveyor construction for retrieving and reentering trays into the vertical farming robot.

Detailed Description of the Invention

In figure 1 is illustrated an embodiment of a vertical farming robot according to the invention. The vertical farming robot is enclosed in a housing 10. The inner workings will be explained with reference to the further drawings, but an important aspect of the invention is illustrated in figure 1.

In the housing 10 is provided an opening 20 allowing access and exchange of particu larly trays into and out of the vertical farming robot. The opening 20 may vary in height and is provided with shutters 21 such that only the desired necessary opening 20 may be made available when exchanging trays 100 into or out of the vertical farm- ing robot 1.

In figure 2 the outer cladding of the housing 10 has been removed in order to reveal the inner structure. The inner structure mainly comprises two vertical load carrying structures 11, 12 each structure 11, 12 having bearing means 15 in either end of the structure 11, 12 such that a plurality of trays 100 may be positioned on the bearing means 15 in either structure 11, 12 thereby creating two stacks of trays.

The two stacks of trays 30, 40 are arranged with a mutual distance such that a lifting bridge 50 may travel vertically between the two stacks 30, 40.

The lifting bridge may be elevated or lowered to any desired vertical position in the vertical farming robot. In this example only a few trays are positioned in the vertical structures 30, 40, but naturally during normal use the structures 30, 40 will be com pletely filled with trays on each level in order to maximise the use of the installation.

Attention will now be directed to figure 4A and 4B illustrating a plane view of the lifting bridge and an isometric view of the lifting bridge. The lifting bridge is an es sential element in the invention in that it makes it possible to place and retrieve trays from the stack of trays 30, 40 and also carry out other tasks thereby eliminating to a large degree the need for manual labour and manual intervention.

The lifting bridge 50 comprises a frame 51 which together with other frame elements will support a tray. In either end as illustrated in figure 4B the lifting bridge 50 is pro vided with guide and travel rails 52, 53, 52’, 53’ which are adapted to travel on verti cal rails 57, see figure 3, allowing the lifting bridge 50 to travel vertically inside the housing 1.

In this embodiment the lifting bridge 50 is provided with a rack and pinion mechanism 54 in either end which will engage a travelling rail 58 arranged parallel to the guide rails 57, i.e. vertically inside the housing. In this manner the lifting bridge by rotating the rack and pinion mechanism 54 will travel up and down along the rail 58 in order to be positioned adjacent the tray to which it is desirable to retrieve the tray onto the lift ing bridge 50.

The lifting bridge is furthermore provided with a chain conveyor 56 in either end of the lifting bridge. This chain conveyor is special in that engagement members ar ranged at a certain distance along the chain of the chain conveyor project from the chain such that by rotating the chain conveyor it is possible to arrange the projecting engagement means projecting outside the normal periphery of the lifting bridge. Here by it is possible by positioning the lifting bridge next to a tray which it is desired to retrieve from its bearing means that the engagement means project sufficiently far from the lifting bridge such that the engagement means may engage the underside of a tray thereby pulling the tray onto the lifting bridge.

Naturally, the opposite is also possible, i.e. that a tray positioned on the lifting bridge due to the engagement means provided on the chain conveyor 56 may be pushed off the lifting bridge onto the bearing means at a desired location inside the structure 1.

The main object of the lifting bridge is therefore to position and retrieve trays on and from the bearing means in the stacks 30, 40 of trays. By the lifting bridge’s ability to travel vertically along the guide and travel rails 52, 53 due to activation of the rack and pinion mechanism travelling on the travel rail 58 the lifting bridge may therefore carry out its most important task.

Turning back to figure 3 a further conveyor 60 is provided such that as the lifting bridge has retrieved a tray from any level in the stack of trays 30, 40 it may travel to the floor of the structure. At this level the tray on the lifting bridge will be positioned such that by activating the chain conveyor 56 the tray may be transferred to the con veyor 60 which conveyor may transport the tray outside the housing as illustrated in figure 3. When the tray 100 has been transferred to the tray position indicated by 100’ (see figure 3) it is possible to manually inspect or work on the trays or transport the tray away for further processing.

Likewise, it is possible to place a tray in the position 100’ such that the conveyor 60 may transport the tray 100’ onto the lifting bridge which thereafter positions the tray at a desired level in the stacks of trays 30, 40.

The lifting bridge may have further purposes or tasks in that since the lifting bridge is able to be positioned at any position relative to the stack of trays 30, 40 it is possible for the lifting bridge also to carry out various tasks. For example, the lifting bridge 50 may as illustrated in figure 5 be provided with a spraying arrangement which in this schematic embodiment comprises 4 nozzle devices 61 which may be moved from an inactive position indicated in full lines to a raised active position indicated by dashed lines. By supplying water, fertilizer and/or other liquid substances to the nozzle devices 61 it is possible to irrigate and fertilize and provide other nutrients and liquid/mist treat ments of plants provided in the trays adjacent to the lifting bridge 50.

In another embodiment illustrated in figure 6 the lifting bridge 50 may for example be provided with a longitudinal rail 62 allowing a gantry 63 to travel along the length of the lifting bridge and thereby also along the length of a tray positioned on the lifting bridge. The gantry may be provided with spraying nozzles, cameras or other sensors such that the immediate environment above each tray may be inspected and treated in a very detailed manner.

The gantry 63 may be remotely operated as may the spray devices 61 as discussed above with reference to figure 5, for example from a control unit outside the structure 1. In this manner it is possible to inspect and treat any tray inside the stack of trays 30, 40 without having to bring the trays outside the structure.

A method of using an installation as described above will now be disclosed. However, it should be noted that the description is very simplified and will only focus on the main parts of the method. A number of trays are prepared for example by placing a growth media inside a growth tray and inserting seeds or seedlings into the growth media. After this the growth trays, i.e. one or more growth trays depending on the size, are positioned in side a tray. The tray is positioned in front of the structure 1 such that the conveyor 60 may transport the tray with the growth trays with the growth media and seedlings into the installation.

The tray with growth trays is thereafter by means of the chain conveyor pulled onto the lifting bridge and the lifting bridge will elevate the tray carrying the growth trays to a predetermined position in one of the stacks 30, 40 and by reactivating the chain conveyor 60 push the tray onto the bearing means thereby arranging the growth trays in a predetermined position.

After this, due to the enclosure of the structure 1, the growth conditions inside the structure may be very precisely and tightly controlled such that optimum circumstanc es with respect to humidity, temperature and the like, is provided for the seedlings. In this connection the underside of the tray is provided with artificial lights such that the optimum amount of light may be provided to the seedlings in the growth trays in order to advance and control the progress of the seedlings.

Likewise, the C02 content inside the structure may be controlled and by ventilation means the C02 may be kept at optimum levels depending on the plants which are be ing propagated inside the structure. By furthermore activating the sprayers or other means for moisturizing the growth media the optimum humidity both on the growth media and in the air immediately above the growth media may be controlled and op timized such that the best growth conditions are provided for the seedlings.

Likewise, when moisturizing the growth trays the moisture, typically water, may be mixed, for example with a liquid fertilizer, such that important nutrients and salts are also provided at proper intervals.

In order to control the progress of the seedlings any tray from the stack of trays 30, 40 may be pulled onto the lifting bridge 50 and for example by means of the gantry 63 provided with cameras and other sensors may be visually inspected inside the struc- ture in order to manually control that the programmed growth procedure, i.e. provision of a fertilizer and other nutrients as well as moisture, C02 etc. also provides the opti mum growing conditions reflected in the propagation of the seedlings in the growth trays. Should this visual inspection with for example video cameras mounted on the gantry 63 indicate that something is amiss in a growth tray, the lifting bridge may transport the desired tray down and transfer the tray on to the conveyor 60 whereby the desired tray and growth trays may be transported outside the structure for manual visual in spection. In this manner a substantially complete automatic vertical farming robot is provided where a minimum of labour intervention is necessary, and at the same time it is possi ble at very short notice to intervene in a growth tray in order to ensure that the correct procedure is being followed.

Further miscellaneous features of the structure may be that each tray in its position in the stack of trays automatically by valve devices is coupled to a drainage system such that any water provided in the growth trays may be drained off maintaining the opti- mum equilibrium and humidity surrounding the plants.

In fig. 7 is schematically illustrated a side view of a tray 100 carrying a growth tray 101, resting on bearing means 15. It shall be noted that the bending in the illustration is exaggerated for illustrative purposes. In reality a typical tray will be approx. 6 m long and the bending will be measured in a few millimetres. The tray 100 has a longi tudinal beam 102 substantially spanning the length of the tray 100, such that in use either end of the longitudinal beam 102 rests on the bearing means 15. A middle sec tion 103 of the longitudinal beam has a reinforced section. The reinforced section 103 is either an integral part of the longitudinal beam 102, or is connected to the longitudi- nal beam in a manner allowing loads from inner/growth trays 101 to be transmitted to the bearing means 15.

As is evident in this embodiment the reinforced section 103 extends above the longi tudinal beam 100, such that in use an inner/growth tray 101 comprising growth medi- um, rests on said reinforced section 103. As the growth tray 101 is supported in two places away from the ends of the tray 101 the load on the growth tray 101 is dimin ished. At the same time the middle section 103 of the longitudinal beam 102 is strengthened, in order better to counter the load, which ultimately is transferred to the bearing means 15.

The consequence is substantially plane growth trays, such that water, nutrients etc. are distributed evenly on and in the growth medium and remains so, as there is no slant in the tray which could otherwise cause liquid to percolate to lower parts of the tray. Turning to fig. 8 the construction illustrated in fig. 1 has been stripped of cladding and a substantial amount of the inner workings illustrated in fig. 2 has also been removed in order to illustrate the skeleton constituting the carrying structure. The stack of trays 30, 40 are carried by bearing means 15 arranged along either opposing walls, where the stacks 30, 40 are spaced allowing the lifting bridge (not illustrated) to travel verti cally between adjacent stacks 30, 40. The lifting bridge will by a rack and pinion mechanism, see fig. 2 be able to travel vertically along rail 58, guided by the guid- erails 57, which inter-acts with the guide and travel rails 52, 52’, 53, 53’ on the lifting bridge (see fig. 2).

One of the important features of the vertical farming robot according to the invention is the ability to transport any tray from any position inside the housing to an outside position. This is as described above in part facilitated by the lifting bridge. Another important feature is the construction illustrated in fig. 9. In order to only illustrate de- tails around the parking position of trays outside the housing, non-relevant features are not illustrated. Centrally the conveyor 60 is provided. The conveyor belt 64 is provid ed with flaps 65 projecting away from the conveyor belt’s surface.

As the lifting bridge has brought down a tray to be transported outside to the parking position 110, a flap 65 on the conveyor belt 64 will engage the underside of the tray and transport the tray outside onto the parking position 110. Here one or more growth trays (not illustrated) will be elevated relative to the tray by activating a growth tray lifting mechanism 112. The growth tray lifting mechanism will engage the underside of a growth tray, by projecting members 114, which when elevated projects up through the lattice work of the tray and engages the underside of the tray. At this time the growth tray may be removed and another growth tray positioned on the tray, or after inspection the growth tray may be lowered again. By reversing the travel direc tion of the conveyor belt 60 a flap 65 will again engage and pull the tray back into a position where the tray may be transferred to the lifting bridge and brought into a de- sired position inside one of the stacks 30, 40.

The various aspects of the invention have been explained with reference to the sche matic figures. In addition to the described features the installation comprises a number of various sensors, for example temperature, humidity, C02 level etc. also a number of sensors cooperating with mechanics of the installation are also provided, such that a control unit at all times will be in control of the entire installation.

Claims

1. A vertical fanning robot, comprising one or more stacks of trays, each tray accom modating growth medium, where each tray is arranged one over the other on separate bearing means, and where a lifting bridge is arranged adjacent the one or more stacks of trays, where said lifting bridge is elevated or lowered to a desired position by a lift ing mechanism, where said lifting bridge comprises engagement means for engaging a desired tray and pulling said tray from the bearing means onto the lifting bridge and/or pushing said tray back on said bearing means, and where a desired tray may be low- ered and transferred onto a conveyor, which conveyor transports the tray to an outside location from the vertical farming robot, or where said conveyor transports a tray from a location outside the vertical farming robot and into a position where the tray is pulled onto the lifting bridge.

2. The vertical farming robot according to claim 1 wherein the engagement means on the lifting bridge is a conveyor having an endless conveyor belt arranged for rotation, and where the conveyor is provided with engagement fins extending from the surface of the conveyor belt, such that in use the engagement fins may be brought into en gagement with the underside of a tray in order to move the tray, either away from the bearing means onto the lifting bridge or push the tray from the lifting bridge onto the bearing means.

3. The vertical farming robot according to claim 1 wherein each tray has one or more inner trays, which inner tray(s) is/are removably arranged in the tray, and where the tray at least along a lower edge is provided with an indentation.

4. The vertical farming robot according to claim 1 wherein each tray has an underside or a lattice work constituting an underside, and where lights are arranged on said un derside, for providing light to plants growing in the tray below.

5. The vertical farming robot according to claim 1 wherein two stacks of trays are ar ranged with a horizontal distance between them allowing the lifting bridge to operate in the space between the two stacks, and where a housing is provided enclosing the two stacks and the space between the two stacks, where said housing has a closable opening, said opening allowing trays to be retrieved from and inserted into one of the stacks of the vertical farming robot.

6. The vertical farming robot according to claim 5 wherein a further third stack of trays is arranged adjacent the stack of trays not adjacent the closable opening.

7. The vertical farming robot according to any preceding claim wherein the lifting bridge has one or more of the following means:

- for scanning a tray and transmitting the scan to a remote location, either when said tray is on the bridge or in the stack;

- for watering the trays, where said watering means may be nozzles creating a mist above a particular tray, or a sprout for introducing water and/or fertilizer into the growth medium;

- for registering moisture and/or temperature and/or CO2 content in the air and/or an insertable probe for registering pH and/or humidity in the growth medium.

8. The vertical farming robot according to claim 1 wherein each tray has a carrying frame structure comprising shorter lateral beams substantially spanning the width of a tray and longer longitudinal beams, substantially spanning the length of the tray, such that in use either end of the longitudinal beams rests on the bearing means, where the longitudinal beams in a middle section has a reinforced section, and where the rein forced section is either an integral part of said longitudinal beam, or is connected to the longitudinal beam in a manner allowing loads from inner trays to be transmitted to the bearing means.

9. The vertical farming robot according to claim 8 wherein the reinforced section ex tends above the longitudinal beam, and where in use an inner tray comprising growth medium, rests on said reinforced section.

10. Method of propagating plants using a vertical farming robot according to claim 1, where said vertical farming robot comprises one or more stacks of trays, each tray accommodating growth medium, where each tray is arranged one over the other on separate bearing means, and where a lifting bridge is arranged adjacent the one or more stacks of trays, where said lifting bridge is elevated or lowered to a desired posi- tion by a lifting mechanism, where said lifting bridge comprises engagement means for engaging a desired tray and pulling said tray from the bearing means onto the lift ing bridge and/or pushing said tray back on said bearing means, and where a desired tray may be lowered and transferred onto a conveyor, which conveyor transports the tray to an outside location from the vertical farming robot, or where said conveyor transports a tray from a location outside the vertical farming robot and into a position where the tray is pulled onto the lifting bridge, wherein at least one tray is prepared outside the vertical farming robot with growth medium and seedlings, and thereafter introduced into the vertical farming robot, such that the lifting bridge may retrieve the tray and lift the introduced tray to a desired position in a stack, by placing the tray on bearing means on a free spot in the stack, and where the lifting bridge comprises means for distributing water, fertilizer, monitoring the growth progress, and where each tray is identifiable such that the lifting bridge may be instructed to place or re trieve any tray from any bearing means in the vertical farming robot, and if desired place any tray on the conveyor for retrieving or entering trays into the vertical farming robot.