SE2250782A1

SE2250782A1 - Method and device for handling plants

Info

Publication number: SE2250782A1
Application number: SE2250782A
Authority: SE
Inventors: Erik Ljungberg; Westendorp Ruben Van
Original assignee: Bracke Forest Ab
Priority date: 2022-06-23
Filing date: 2022-06-23
Publication date: 2023-12-24
Also published as: WO2023247706A1

Abstract

The invention relates to a plant handling tool for gripping plants having a stem and a root plug, the plant handling tool comprising first gripping means for gripping the stem of a plant, and second gripping means for gripping a root plug of the plant. At least one of the first gripping means for gripping the stem and the second gripping means for gripping the root plug is displaceable in relation to the other of said gripping means along an axis being parallel to or representing an intended longitudinal axis of a stem of a plant when the plant handling tool is positioned for gripping a plant.

Description

METHOD AND DEVICE FOR HANDLING PLANTS Field of the invention The present invention relates to relocation of plants, and, more specifically, to a plant handling tool for relocating plants from a first position to a second position. The invention also relates to a system, a planter, a method and a computer program implementing the method according to the invention.

Background of the invention A need for relocation of seedlings/plants may exist in various different situations. For example, plant relocation may be used in connection with regeneration work in forests following forest harvesting where harvested forest oftentimes is regenerated by the planting of plants. The handling of such plants in the planting process may comprise a need for relocating a plant from one location to another.

For example, a planter may be utilised in the planting process. Such planters are previously known and, e.g., marketed by the applicant under the names "Bracke P11.a", "Bracke P12.a". Such planters are intended to be attached, e.g., to any kind of suitable machine, such as a harvester, a crane, an excavator, the backhoe of a tFaCtOl' etC.

With regard to planters of this kind, the plants to be planted are received in individual cells of a magazine/carousel of the planters prior to the actual planting process. Such magazines/carousels may have different designs and, e.g., be of a circular design. During operation, the carousel magazine is rotated intermittently to open the cell bottoms one by one so as to allow the plugged plants to escape downwards through an extraction opening into a planting tube and subsequently to the planting tool.

As a further alternative, the magazine may be of a generally quadrilateral design where displaceable bottom plates are stepwise moved aside in order to open the bottoms of the cells of the magazine one by one and to release one plant at a time to subsequently enter a planting tool for planting the extracted plant.

These solutions work well but have in common an element of manual handling of the plants when the individual cells of the magazines/carousels of the planters are to be loaded with plants, which is carried out manually. lO Similar manual elements of plant relocation may also be present in plant schools/ tree nurseries, greenhouses and argriculture in the preparation of plants to be distributed e.g. to forests to be used in the forest replanting process.

Summary of the invention lt is an object of the invention to provide a method and system that may facilitate the handling of plants, and provide for increased capacity, productivity and simplification of devices according to the background art.

According to a first aspect of the invention, it is provided a plant handling tool for gripping plants having a stem and a root plug, the plant handling tool comprising: first gripping means for gripping the stem of a plant, and second gripping means for gripping a root plug of the plant.

At least one of the first gripping means for gripping the stem and the second gripping means for gripping the root plug is displaceable in relation to the other of said gripping means along an axis being parallel to or representing an intended longitudinal axis of a stem of a plant when the plant handling tool is positioned for gripping a plant.

Plants such as, for example, seedlings, are, oftentimes, stored and/or being delivered in trays comprising a plurality of integrated pots where the plants may have been cultivated from the beginning in such trays, e.g., in tree nurseries. When the trays comprising plants being ready for use, for example in reforestation, are delivered the plants are manually handled by hand. lt is to be noted that the term "plant" is used herein as a general term and includes, e.g., seedling etc.

As discussed above, there exist planters for facilitating the actual planting process, where the planters comprise magazines/carousels that carry the plants during reforestation. These magazines/carousels are loaded manually by an operator filling individual plant cells of the magazines/carousels with plants, in general being in the form of plugged plants, i.e. plants comprising a root plug comprising soil and/or other material surrounding roots of the plant for protecting the roots and facilitating growth of the plant to increase the probability of successful rooting during transplantation. lO During such loading of magazines/carousels, the plants are taken out from the individual pots of the trays in which they are delivered and moved, usually one by one, to the magazine/carousel of a planter being used in the reforestation. ln addition to this manual handling being time consuming and taking resources that may be used in a more efficient manner, such as when an operator of a forest machine carries out the plant loading of magazines/carousels of a planter, the relocation of the plants from the tray in which they are delivered to the magazines/carousels may subject the plant and perhaps in particular the root/root plug of the plant to undesired/unintentional stress that may harm the possibilities of successful growth of the plant once transplanted.

According to the invention, it is provided a plant handling tool that is capable of gripping and relocating plants for transplantation that in addition to relieving, e.g., a forest machine operator from the manual element of loading magazines/carousels also allows the plants being alleviated from at least some of the stress that the plant is subjected to when being transported in the magazine/carousel pending the particular plant being planted.

At least one of the first gripping means for gripping the stem and the second gripping means for gripping the root plug is a device displaceable in a general longitudinal direction of a plant in position to be gripped in relation to the other said gripping means. This provides for a solution where, for example, the plant may be gripped by one of the gripping means and either of the gripping means then being repositioned in relation to the other gripping means in order to facilitate gripping of the plant using both gripping means. This, in turn, may allow for a careful handling of the plant by holding both the stem and the root plug so as to ensure keeping it intact and avoid soil from falling from the root plug and expose the naked root. ln addition to using the plant handling tool e.g. in reforestation as described, the plant handling tool according to the invention may be utilised also e.g. in green houses, where plants may be relocated e.g. to be replanted in larger pots for further growth. The plant handling tool according to the invention may also be utilised e.g. in agriculture, where plants may be planted, e.g. from trays of the described kind, and e.g. utilising machines being suitable for such use. lO According to embodiments of the invention, the first gripping means is displaceable along the displacement axis in relation to the second gripping means, where the first gripping means is positionable in at least one first position, below the second gripping means along said displacement axis, and at least one second position, above the second gripping means along said displacement axis. This allows for a solution where, for example, the plant may be gripped by its stem using the first gripping means/device for gripping the stem, to then be raised and freed e.g. from a pot of a tray or other means supporting the plant, to thereafter allow also the root plug to be gripped by the second gripping means/device. The plant may then be safely relocated while both stem and root are supported to protect the in general fragile plant by ensuring the integrity of the root plug.

According to embodiments of the invention, the first gripping means is displaceable from said first position to said second position, and vice versa, while maintain the grip of a stem of a plant. This allows for example, that the plant may be gripped and supported as above, and also be released in a gentle manner e.g. by releasing the grip of the root gripping means and then lower the plant using the stem gripping means prior to releasing the plant by releasing the grip of the stem gripping means.

According to embodiments of the invention, the first gripping means comprises grip elements, such as jaws, for gripping a stem of a plant. Thereby the grip elements may be suitable formed for allowing a secure grip while simultaneously avoiding the plant being subjected to unnecessary stress.

According to embodiments of the invention the jaws are formed by, and/or provided with a layer of, a resilient material to provide suitable friction against the grip elements slipping along the stem of a plant while gripping the stem. This may further allow for a gentle handling of plants.

According to embodiments of the invention, the second gripping means may comprise grip elements for gripping the root plug of a plant. This may allow for a secure while gentle grip to support the roots/root plug, which may be very fragile. Such grip elements may have any suitable form, and, e.g., be adapted to the shape of the root plugs of the plants that are to be picked by the tool. For example, such grip elements may, e.g., be arc shaped, V-shaped, U-shaped or be of any other lO suitable design, e.g in order to be adapted to the shape of the root plug by the particular plants to be picked by the tool.

According to embodiments of the invention, the first and/or second gripping means comprising replaceable grip elements adaptable to different types of plants to be gripped. This provides for a solution where the grip elements of a plant handling tool may be adapted to the plants currently being handled, and the plant handling tool may be adapted to various different types of plants in a straightforward manner.

According to embodiments of the invention, the plant handling tool comprises at least one actuator being configured to control grip elements of the first gripping means, and grip elements of the second gripping means, the at least one actuator controlling one or more mechanical linkages connecting the at least one actuator to the grip elements. This provides for an efficient design solution of the plant handling tool. The actuators may be of one or more from electrical actuators, hydraulical actuators, mechanical actuators.

According to embodiments of the invention, the plant handling tool comprises a first and a second actuator, the first actuator being configured to control grip elements of the first gripping means, and the second actuator being configured to control grip elements of the second gripping means, each of the first and second actuator controlling a mechanical linkage connecting the actuators to the grip elements, respectively. Although the first and second gripping means may be controlled by a same actuator, the use of different actuators for each gripping means may facilitate the individual control of the first and second gripping means.

According to embodiments of the invention, the plant handling tool comprises a an actuator for controlling the displacement of the first and/or second gripping means in relation to the other of said gripping means. This, too, provides for an efficient design solution of the plant handling tool.

According to embodiments of the invention, the actuator for controlling the displacement of the first and/or second gripping means in relation to the other of said gripping means may also be utilised to control grip elements of at least one of the first and second gripping means. lO According to embodiments of the invention, the first and/or second gripping means may be configured to be displaced by the actuator rotating a threaded shaft, where the first and/or second gripping means may be rotationally fixed in relation to the threaded shaft and comprise a hole portion provided with an internal thread that cooperates with the threads of the threaded shaft to run along the shaft while the shaft is rotated by the actuator. The first and/or second gripping means may be secured against rotation with the threaded shaft through any suitable means, which may also act as support to increase rigidity of the tool. Such means may e.g. comprise a rod being parallel to the threaded shaft, or any other suitable means.

According to a further aspect of the invention it is provided a system comprising a plant handling tool according to the above, a location for storing plants to be gripped by the plant handling tool, and receiving means, such as a receptacle, e.g. an opening, for receiving a plant when being released by the plant handling tool following the plant being gripped by the plant handling tool, where plant handling tool manoeuvring means a robotic arm may carry the plant handling tool, and be configured to manoeuvre the plant handling tool to the location for storing plants and, following gripping of a plant, manoeuvre the plant handling tool to the receiving means and release the plant by releasing the grip.

This provides for a solution where a system for efficient relocation of plants is provided, and where means, such as a robotic arm or other suitable means, may be utilised to position the plant handling tool to various positions comprising plants, and then transport the plants to a second location for release of the plants. lnstead of a robotic arm, for example, the plant handling tool may be carried by a traverse system to allow for the desired manoeuvring of the plant handling tool.

According to embodiments of the invention, the receiving means may comprise a further similar plant handling tool, which may further move the plant to another position. ln this way, the plants may be moved e.g. longer distances in case needed. A plurality of tools may be utilised to consecutively move a plant, where the one or more further tools may be of a design according to the invention or of a different kind.

With regard to the positioning of the plant handling tool in relation to the plants this may be accomplished in various different ways. For example, the plants to be lO relocated may, as discussed above, be arranged in trays comprising integrated pots, or other suitable means, that allow a predetermined inter plant distance to be used between individual plants. ln this way, by suitably locating the one or more trays, e.g. at predetermined locations and possibly in a predetermined orientation, the plant handling tool may be suitably programmed to grip, relocate, and release the plants one by one by being manoeuvred to the various different locations of plants being defined by the tray, e.g. through the use of a suitable coordinate system defining the locations of the plants, e.g. in terms of individual pot positions of a tray in relation to the tool, and the one or more positions for releasing the plants, so that an efficient relocation of the plants may be carried out.

According to embodiments of the invention, one or more sensors and/or one or more cameras are used to determine the location of the plants, so as to allow plants to be picked without prior knowledge of the exact locations of the plants to be picked. According to embodiments of the invention the system is configured to, when gripping a plant: manoeuvre the plant handling tool to a position allowing the stem to be gripped by the stem gripping means, grip the stem through the use of the first gripping means, displace the first gripping means in relation to the second gripping such that thereby the gripped plant is displaced in relation to the second gripping means to allow the root gripping means to grip the root plug of the plant, and grip the root plug of the plant by the root gripping means.

This hence provides for a solution making efficient use of the plant handling tool according to the invention.

According to embodiments of the invention, the system is further configured to, when releasing a plant: releasing the grip of the second gripping means followed by releasing the grip of the first gripping means, or lO releasing the grip of the first and second gripping means simultaneously.

This provides for gentle release of gripped plants following relocation, where the release can be carried out in the way considered most practical for the current installation.

According to another aspect of the invention it is provided a planter comprising a system according to the above, and means for planting a released plant received by the receiving means. The means for planting a released plant may comprise any suitable solution, such as any of the discussed prior art solutions, and where the picking of the plants and releasing them at a point of release is carried out according to embodiments of the invention.

According to embodiments of the invention, the planter is further being configured to receive one or more trays comprising plants, e.g. at predetermined locations, and the planter further being configured to manoeuvre the plant handling tool to grip a plant from the one or more trays and release picked plants at a position for releasing the plant for transplantation or other handling. The trays may each comprise a plurality of integrated pots, each pot comprising a plant.

According to the invention, it is hence provided a device being configured for use in transporting the plants from one location to another, such as from a location where the plant is stored in a tray to a location that allow the plant to be planted at a desired location. However, it is also contemplated that the plant handling tool may be utilised in any kind of system for relocation/transplantation of a plant.

According to embodiments of the invention, the device being configured for use in transporting the plants from one location to another may comprise sensor means, such as one or more cameras and/or one or more laser/LIDAR scanning sensors, or any other suitable kind of sensor means, for, e.g., through suitable signal processing, determine a position of a plant prior to gripping, relocating and releasing the plant. ln this way plants may be automatically gripped irrespectively whether the location of the plant is known in a control system controlling the gripping of a plant or not. lO Such sensor means may also be utilised to determine whether a designated plant position is in fact occupied by a plant to avoid attempts to grip non-existent p|ants.

According to the invention, situations where p|ants are picked one by one manually by hand can be avoided while still ensuring that the seedlings/plants are handled with the care that oftentimes is required due to the fragile stems and root systems.

The invention also relates to a method for gripping a plant through the use of a plant handling tool.

Further characteristics of the present invention and advantages thereof are indicated in the detailed description of exemplary embodiments set out below and the attached drawings. Brief description of the drawings Fig. 1 illustrates a first perspective view of a plant handling tool according to embodiments of the invention; Fig. 2 illustrates a view from the side of the plant handling tool of fig. 1; Fig. 3A illustrates a mechanical linkage of the plant handling tool of fig. 1; Fig. SB illustrates a second perspective view of the plant handling tool of fig. 1; Figs. 4A-D illustrates a method for gripping a plant according to embodiments of the invenﬁon; Figs. 5A-C illustrates a method for releasing a plant according to embodiments of the invenﬁon; Fig. 6 illustrates an alternative method for releasing a plant according to embodiments of the invention; Fig. 7 illustrates a plant handling tool according to embodiments of the invention attached to a robotic arm for manoeuvring the plant handling tool when relocating p|ants; Fig. 8 illustrates a plant handling tool and robotic arm according to embodiments of the invention attached to a machine. lO lO Detailed description of exemplary embodiments Embodiments of the present invention will be exemplified in the following in view of a particular exemplary embodiment of a plant handling tool. lt is to be understood that according to embodiments of the invention the plant handling tool may have various different designs that still fall within the general scope of the invention, and the device is hence not limited to the particular embodiments being exemplified in the following.

Fig. 1 illustrates a perspective view of a plant handling tool 100 according to an exemplary embodiment of the invention. The plant handling tool 100 comprises first gripping means in the form of a stem gripping device 101 having grip elements in the form of a pair of jaws 101A, 101 B, which, in use, are configured to grip the stem of a plant by being moved towards each other in the direction of the arrows so as to grip the plant by urging the jaws 101A, 101 B towards the stem of the plant to grip the same. The gripping and releasing of the stem through the use of the jaws 101A, 101 B is controlled by an actuator, such as an electric motor 102 (visible in fig. 2), which through a mechanical linkage 103 connecting an output shaft of the electric motor 102 to the jaws can be operated to cause the jaws 101A, 101 B to releasably grip the stem of a plant. The electric motor 102 may, for example, be an electric stepper motor. Such motors may be controlled with high accuracy to carry out the desired gripping of the stem of the plant. lt is to be understood, however, that according to embodiments of the invention the actuator may consist of any other suitable kind of actuator, such as a hydraulically or pneumatically operated actuator that is capable of providing the desired gripping and releasing motion of the jaws 101A, 101 B. As is realised, the grip elements may have various different designs.

Fig. 3A illustrates the mechanical linkage 103 of fig. 1 for controlling the grip elements of the stem gripping device 101. An output shaft 301 of the actuator 102 (not shown) drives a gear wheel 302 which is meshed with a similar gear wheel 303. The actuator 102 may selectively rotate the gear wheel 302, and thereby gear wheel 303, in both directions of rotation to thereby selectively open and close the grip of the grip elements, i.e. jaws 101A, 101 B. A gear arm 304 is affixed at one end to the gear wheel 302, and the other end is connected to a link arm 305 by means of a joint 306. Botation of the gear wheel 302 in a clockwise direction rotates the gear arm 304, lO ll which in turn drives the link arm 305 which, through the link 307 rotates such that the grip element 101 B is urged towards grip element 101A. the grip element 101 B is simultaneously subjected to a similar motion when gear wheel 302 drives gear wheel 303, with the result that the grip elements 101A, B are urged towards each other to thereby grip the stem of a plant. Fïotation of the shaft 301 in the counter-clockwise direction will release the grip. lt is to be understood that the illustrated mechanical linkage is only exemplary, and for illustrative purposes only, and may be of various different designs while still allowing the desired functionality, as is appreciated by the person skilled in the art.

Furthermore, the plant handling tool 100 also comprises second gripping means in the form of a root gripping device 104 comprising grip elements, 104A, 104B, which, according to the present example, are constituted by a pair of arc-shaped plates. The arc-shaped plates 104A, 104B are configured to grip a root portion of the plant, where in particular this root portion may constitute a root plug, i.e. the roots of the plant being surrounded by soil and/or other material facilitating growth of the plant. As is understood, the grip elements for gripping the root may have any suitable design, and e.g. be arc shaped, V-shaped, U-shaped or of any other suitable design to be adapted to the shape of the root plug of the particular plants to be handled by the tool.

The operation of the second gripping means 104, i.e., gripping and releasing the root portion of the plant, is controlled by a second actuator 105, such as a second stepper motor, which through suitable mechanical linkage 106 operates the arc-shaped plates 104A, 104B. This may be carried out in a manner similar to what has been discussed with respect to the stem gripping means. ln addition to the two different kinds of gripping means that are provided to grip the stem and root, respectively, of a plant, the plant handling tool 100 according to embodiments of the invention is, as discussed further, characterized by one of the gripping means being displaceable in relation to the other gripping means along an axis essentially representing, or being parallel to, an intended longitudinal axis of a stem of a plant, illustrated by "B" in fig. 2, when the plant handling tool 100 is positioned for gripping a plant. According to the illustrated example, the stem gripping lO 12 device 101 comprising the jaws 101A, 101B is displaceable in the longitudinal direction generally indicated by an axis "A" in the figure, hence representing an axis being parallel to the general intended direction of a stem of a plant when the plant handling tool is in position for gripping a plant, where the stem gripping means are displaceable to an extent such that the stem gripping means 101A, 101 B may be positioned both below and above the grip elements 104A, 104B of the root gripping device along the general Iongitudinal direction A illustrated in figs. 1-2.

This displacement of the stem gripping device 101, according to the illustrated example, controlled by means of a third actuator 107, which according to the illustrated example, is a third stepper motor but which, similar to the above, may consist of any other suitable kind of actuator, such as hydraulic or pneumatical actuator etc. The third actuator 107 rotates a threaded shaft 108, where the stem gripping device 101 of the plant handling tool 100 comprising the jaws 101A, 101 B, actuator 102 and mechanical linkage 103 is threaded onto the threaded shaft 108 through a hole portion having internal threads corresponding to the threads of the threaded shaft so that the stem gripping device 101, and thereby the jaws 101A, 101 B will move along the shaft 108 as the shaft 108 rotates. Depending on the direction of rotation of the shaft 108 the stem gripping device 101 will move up or down. The stem gripping device 101 is further supported by, and also slides along, a bar 111 for reasons of rigidity of the tool, and to prevent the stem gripping device 101 from rotating with rotation of the threaded shaft 108. ln this way, the position of the stem gripping device 101 may be alternated between a first position, above the second gripping means, i.e., root gripping device 104, as is the case in figs. 1-2, and a second position below the root gripping device 104 in a general direction of a plant in position to be gripped, i.e. along the axis A. The second position is schematically illustrated in fig. SB. Figs. 1-2 also illustrates an energy chain 112 for powering the stepper motor 102, and a connector 113 for powering the stepper motor 105. The plant handling tool is powered through one or more connectors 114, 115, 116 (the connectors are also visible in fig. 7) through which the components of the plant handling tools are then also powered. ln addition to power various control signals may also be communicated through the connectors 114-116. lO 13 lt is to be noted that the root gripping device may instead be configured to be displaceable in relation to the stem gripping device. According to embodiments of the invention, both the stem gripping device and root gripping device may be displaceable in relation to each other along a general longitudinal axis of a plant to being handled. lt is also to be noted that with regard to e.g. the jaws 101A, 101 B of the stem gripping device, these may be exchangeable, and/or comprise exchangeable grip elements, so as to, for example, allow the grip, and thereby the plant handling tool, to be adapted to different kinds of plants and the particular kind of plant it is currently to be used for.

Furthermore, the jaws of the stem gripping device may be configured such that the portion intended to grip the plant may be formed by, and/or be provided with e.g. a layer of, such as a cushion, a resilient material providing adequate friction while gripping the stem to allow for lifting of the seedling while simultaneously reducing the risk that the stem is accidentally damaged by the grip being too tight and/or the gripping means sliding along the stem while lifting due to a poor grip. Such resilient means may, for example be formed by TPU or any other suitable material.

According to the illustrated example, the grip elements of the stem gripping device may have a generally flat portion that is intended to grip the stem in order to ensure a firm grip of the plant giving the normally very small diameter of the stem of seedlings. Although it is contemplated that the grip elements of the stem gripping device may have e.g. an arc shape, a generally flat surface may prove beneficial to accommodate different plants, since the stem may vary in thickness from plant to plant. ln case the diameter of the arcs would be improper and thereby not suitable to the plant currently being gripped, the grip may not be firm enough with the result that the grip elements may slide along the stem and possibly harm e.g. branches. Furthermore, since the distance between branches on a small plant in general is very limited, the grip elements of the stem gripping device may have a relatively limited height, which, again, may be adapted to the particular kind of plant that currently is being handled. lO 14 Since the gripping means are displaceable in relation to each other in the general longitudinal direction of the seedling the jaws of the stem gripping device may be controlled to grip the stem of the seedling as close as possible to the root plug, that is, as low as possible on the stem, in order to avoid any branches of the seedling being unnecessarily broken since such branches in general are very weak.

Similarly, with regard to the second gripping means these may, for example, also be replaceable to provide for use of root grips having different shapes and/or lengths in order to be adapted to, for example, different types of plants and/or roots/root plugs of the plants. The second gripping means may be formed by any suitable material such as plastic or metal. ln addition to, or as an alternative to, adapting the first gripping means to different types of plants, e.g, a control system controlling operation of the plant handling tool may be programmed to receive an identification of the type of plant being handled, e.g. through an operator interface such as a screen, keyboard, buttons, etc. to thereby program e.g. the inter-jaw distance at which the clamping is controlled to be stopped and the stem being deemed to be gripped. According to embodiments of the invention, force sensing means for sensing the gripping force of the jaws may be used instead (or in addition). Such force sensing means may e.g. consist of one or more force transducers and/or by sensing the motor current (or corresponding means for powering the actuator of the gripping means, such as a hydraulic flow and/or pressure).

An exemplary use of the plant handling to according to embodiments of the invention will be exemplified with reference to figs. 4 A-D. ln the figures the plant handling tool is highly schematically illustrated in order to illustrate the principle only, and as discussed, various designs may be utilised to accomplish the functionality according to the invention.

Fig. 4A schematically illustrates a plant handling tool 400, in its simplest form essentially comprising the two gripping means 401 ,404. For reasons of simplicity and illustration references will be made to elements of the specific example being illustrated in figs. 1-3. The plant handling tool is illustrated as being ready for gripping a plant 410. The actual positioning of the plant handling tool 400 will be discussed lO further below. The plant handling tool 400 consequently comprises a stem gripping device 401, having jaws 401A, 401 B, and a root gripping device 404, having suitable grip elements 404A, 404B such as plates. The plant 410 is schematically illustrated and comprises a stem 411 and a root plug 412. The plant handling tool 400 has been positioned to a suitable location for gripping the plant, for example in a position aligned with the general longitudinal axis of the plant, e.g., being represented of the stem of the plant to be gripped, and in a manner such that the first gripping device 401, which have been controlled to be positioned underneath the root gripping device, i.e., a position corresponding to the position in fig. 3B, is, in a suitable position for gripping the stem 411 of the plant 410. This positioning is discussed further below. ln fig. 4B the plant 410 is gripped by the jaws 401A, 401 B of the first gripping 101 means by suitably controlling the actuator 102 to move the jaws 401 A, 401 B to thereby grip the stem using the jaws 401A, 401 B to an extent where the grip of the plant 410 is sufficiently firm to be gripped and allow the plant to be lifted, e.g., out of a pot of a tray, and expose the root plug. As discussed, the jaws 401A, 401 B may be exchangeable, and/or otherwise adapted to the specific kind of plants currently being handled by the plant handling tool 400.

Following the plant 410 being gripped by the jaws 401A, 401 B of the stem gripping device 401 in fig. 4B, the plant 410 is lifted, according to embodiments of the invention, by manoeuvring the stem gripping device 401 in relation to the root gripping device 104 and hence while maintaining the position of the plant handling tool 400. This is illustrated in fig. 4C, where the stem gripping device 401 has been displaced by being raised to a position above the root gripping device 404 in a generally longitudinal direction of the plant 410. According to the illustrated example, the displacement is accomplished by suitably controlling the actuator 107 rotating the threaded shaft 108 such that the portion 110 is moved upwards to the position illustrated in fig. 4C. This also means that the plant has been lifted out from, e.g., a pot of the tray to thereby expose the root plug, which is located behind the grip element 404A in fig. 4C and therefore not visible in the figure. lt is to be understood lO 16 that the displacement may be accomplished using any suitable means, such as, for example, a belt drive, a hydraulic/pneumatic/electric cylinder, etc.

As discussed, according to embodiments of the invention, the root gripping device may instead be configured to be displaceable in relation to the stem gripping device. ln such cases the plant handling tool may instead lifted following the gripping of the stem, while the second gripping means is lowered, e.g. simultaneously or following the lifting, to thereby be repositioned to a position below the stem gripping device. According to embodiments of the invention, both gripping means may be displaceable in relation to each other.

Following the lifting of the plant out from the tray, the root plug is then gripped, illustrated in fig. 4D, by manoeuvring e.g. an actuator such as actuator 105 of fig. 1, such that the arc shaped plates 404A, 404B are moved towards the root plug to support the root plug. Root plugs in general comprise roots covered in soil or other material being favourable to the cultivating of the plant. ln order to avoid the root plug being subjected to unnecessary stress, it may be ensured that the grip of the root gripping device is controlled to more support the root plug than actually firmly gripping the root plug. This may be ensured, for example, by the type of tray being utilized being programmable/selectable in a control system of the plant handling tool so that the arc shaped plates 404A, 404B may be moved to a position corresponding to the exterior of the root plug which hence may be known and stored. The plants are oftentimes delivered in trays comprising a plurality of integrated pots, each pot comprising a single plant. The plants have often been cultivated from seeds in the trays in which they are delivered, and the inter-plant distance of such trays may be well defined, e.g. by the inter-pot distance, and be used e.g. in a control system controlling the operation of the plant handling tool.

Following the gripping by both the stem gripping device 401 and the root gripping device 404 by the plant handling tool 100 the plant 410 is properly secured for being moved to a new location, such as a location where the plant can be released for being transplanted or replanted in an intended position. For example, the plant may be moved to a position where it, when being released, is received by a planting device, where such planting devices may comprise any suitable planting device, such lO 17 as a planting device known in the art, but where hence the actual feeding of the plants to the planting device has been replaced by a solution according to the invention. Alternatively, as discussed, the plant may be released e.g. in a larger pot for further growth.

Hence, when the plant has been moved to a position for being released, the plant is released by releasing the grip of the stem gripping device and the root gripping device. This may be carried out in any suitable manner, where two examples are illustrated in figs. 5A-C, and fig. 6, respectively. ln fig. 5A, following the plant being moved from, e.g., the tray to a desired location for releasing the plant, such as a position allowing the plant to be planted by a planter, the grip elements 404A, 404B of the root gripping device first releases the grip while the stem gripping device still maintains the firm grip of the stem of the plant.

Subsequently, according to the present example and only optionally, the stem gripping means may be controlled to lower the plant by displacing the stem gripping device to the position of, e.g., fig. SB, prior to releasing the plant, fig. 5B. The plant is then released by releasing the grip also of the stem gripping device. This is hence essentially reversing the gripping procedure.

According to embodiments of the invention, either of the stem gripping device and the root gripping device may be released prior to the grip of the other of the first and second gripping device releasing the grip.

According to a further example, illustrated in fig. 6 both the stem and root gripping device may release the grip of the plant simultaneously.

Following the release of the plant, the plant handling tool 400 may be moved to a subsequent position of a subsequent plant to be relocated and the procedure be repeated, e.g. until all plants of a tray, or set of trays have been handled.

Fig. 7 illustrates an exemplary installation for use of a plant handling tool 100 according to embodiments of the invention. According to the illustrated example, the plant handling tool 100 is mounted to the distal end of a robotic arm 710 comprising a first robotic arm portion 711 and a second robotic arm portion 712 being linked together through the use of a first rotation unit 714. The proximal end 713 of the first lO 18 robotic arm portion 711 is attached to a planter by means of a second rotation unit 715. With regard to the planter, this may be of a kind having a similar functionality as the planters discussed above in the background section, or other prior art planters, with regard to the actual planting of the plant following the instance in time a plant is delivered for planting. The invention differs in the manner in which the plants are delivered to a point of reception of the plant.

Hence, instead of the planter being provided with a magazine or similar means for receiving individual plants, and which plants are then discharged one by one from the magazine, e.g., according to any of the prior art solutions for planting, the solution of fig. 7 may be utilised with a planter that, instead of a magazine, comprises a, e.g. designated, area for carrying trays or other suitable means comprising plants, where this surface may be configured to receive, e.g., one or more trays of the kind in which the plants are delivered so that plants being received e.g. from a tree nursery may be placed directly on the planter. Preferably the planter comprises means for securing such trays to the planter to ensure that the trays are kept in position while the planter is in motion, since planters oftentimes form part of, or are attached to, machines that travel highly uneven terrain, thereby also oftentimes generating a jerky motion of the machine carrying the planter.

A principle according to embodiments of the invention is schematically exemplified in fig. 8, where four trays 801-804 comprising pots with plants are illustrated as being positioned on a dedicated surface 805. The figure also illustrates a robotic arm 710 comprising a plant handling tool according to fig. 7. The trays 801-804 are arranged such that the furthermost pant 806 is within reaching distance of the plant handling tool 100 when mounted on the robotic arm 710. According to the exemplary embodiment, the plants are picked one by one starting with plants that are not completely surrounded by other plants. This is because, according to the present example, the robotic arm 710 operates in a single plane parallel to the plane of the surface on which the trays 801-804 are positioned. This, in turn, means that plants surrounding a particular plant, such as, e.g., plant 6 in the figure, must at least partly be picked by the plant handling tool 100 prior to the plant 6 being sufficiently exposed to allow it to be picked. The order of the picking of the plants may be any suitable lO 19 order, and, for example, start with the plant denoted "1 " in the figure, although this is not at all necessary. Any reachable plant may be picked first. According to the illustrated example, the picking order may, for example, start with 1-2-3-4-5 etc., 1-2- 5-10-17 etc. 1-4-9 etc., 16-9-4-1 etc., or any other suitable order. The picking may also be commenced on any of the trays 801-804, e.g. in dependence on the location at which the picked plants are released. According to the illustrated examples, picking starts with plant "1 The planter, furthermore, comprises receiving means 820 being configured to receive the plants when the plants are to be released following being gripped by the plant handling tool 100. The receiving means 820 may comprise any suitable kind of receptacle, or other means, being configured to receive the plant when the particular plant is to be planted by the planter. For example, the receiving means 820 may constitute a receptacle in the form of an opening forming the opening of a channel leading to a plant release mechanism releasing the plant when being transplanted in the ground in reforestation or agriculture. Such solutions are well known in the art, e.g. from the above discussed prior art solutions. According to embodiments of the invention, the receiving means may comprise any suitable means, and, for example, comprise a second tool, of a similar or different kind, to which the plant is delivered, and where the second tool may grip the plant while or following the plant being released by the first tool to then be planted in any suitable manner.

The position of the plant receiving means 820 may be determined such that the position maximise the possible number of trays that the planter can be configured to carry, to increase the time between reloading of trays following all carried plants being picked.

According to embodiments of the invention, the planter or other means carrying the trays may further comprise means for removing empty trays, so that trays comprising plants may be repositioned to a position reducing the distance for transporting the plants. This may be accomplished in various different ways. For example, an empty tray may be pushed away through the use of a cylinder or other means to make room for another of the trays, or otherwise be removed, e.g. by being pushed or allowed to lO fall through a door or similar means to a storage compartment storing the empty trays.

According to embodiments of the invention, the plant handling tool may be operated by an operator controlling the gripping and releasing and possible relocation of the plants. However, such manoeuvring may be time-consuming, and according to embodiments of the invention, the gripping and releasing and relocation of plants is preferably automated. This may facilitate considerably higher plant handling speeds, and on operator may focus on manoeuvring the machine carrying the planter. ln this procedure, the plant handling tool needs to be able to locate the plants in order to successfully pick the plants and carry out the desired relocation of the plants.

This can be carried out in various ways.

According to embodiments of the invention, the area/surface of the planter being configured for receiving the trays may be designed such that, and/or comprise means such that, the trays can be positioned in predetermined positions. ln this way the positions of the trays can be "automatically" known by the control system by prestored coordinates of the trays. Thereby individual positions of the plants may also be automatically defined by the predetermined position of the trays and, for example information in a control system of the planter stating the particular type of trays that are currently being used, e.g. comprising information about the inter-plant distance of the particular tray, and distance from edges of the tray etc. ln this way, by suitably locating the one or more trays, e.g. at a predetermined location and possibly in a predetermined orientation, the plant handling tool may be suitably programmed to grip, relocate, and release the plants one by one by being manoeuvred to the various different locations of plants being defined by the tray so that an efficient relocation of the plants may be carried out.

According to embodiments of the invention, the planter and/or plant handling tool may, although still possibly comprising a designated area for placing the trays, instead or in addition, comprise sensor means such as one or more cameras and/or one or more laser/LIDAR scanning sensors, or any other suitable kind of sensor means, that are capable of identifying individual plants, e.g., through suitable signal processing prior to gripping, relocating and releasing the plant. ln this way, the trays lO 21 need not be positioned with the same accuracy in terms of position, and there is also no need to have prior knowledge of the positions of the plants, but instead the sensor means may be utilized to locate the plants. Sensor means may also be utilised to determine whether a designated plant position is in fact occupied by a plant. This may be arranged to be carried out e.g. by measuring the clamping force of grip elements, e.g. through the current/flow provided to the actuator, and/or sensors according to the above, so that it may be plants are provided for planting as expected. Alternatively, this may be determined e.g. by image processing of images of a camera, or suitable processing of sensor signals of any other kind of suitable SGFISOI".

The use of a plant handling tool, e.g., in forest applications may also provide further advantages. ln general, the plants are cultivated at plant cultivation centres such as tree nurseries where the plants may be organized in trays of the above exemplified kind where the plants are provided with a root plug circumventing the roots of the plants thereby protecting the roots and also facilitates the ability of the plant to root itself at the location of plantation. According to embodiments of the invention, since the trays in which the plants are delivered may also be utilized in the planting process, the root plugs are protected all the way up to the actual plantation of the plant. According to existing solutions, on the other hand, the plants are in general moved by hand from the trays in which the plants are delivered to magazines being specific to the planting device being used. This relocation may expose the root plugs with the risk of the root plugs falling apart due to vibrations and other motions that the machine carrying the planter undergo during operation. This deteriorates the quality of the plant which may further affect the overall result of the plant transplantation in a deforested area or in agriculture. According to embodiments of the invention, this can be avoided to a large extent by using the actual trays in which the plants are delivered all the way up to the moment of planting.

According to embodiments of the invention, consequently, it is provided a solution that allows that no time needs to be assigned for manual picking of the plants one by one from the trays to a magazine of the planter for subsequent planting. Furthermore, it is provided a plant handling tool that may protect the plants while being picked and 22 relocated to another position without subjeoting the plant to unnecessary stress. Also, embodiments of the invention also have the further advantage that the roots of the plant will be protected by the tray all the time up till the actual moment of plantation.

Claims

1.Claims 1 _

2.A plant handling tool for gripping plants having a stem and a root plug, the plant handling tool comprising: first gripping means for gripping the stem of a plant, and second gripping means for gripping a root plug of the plant, wherein: at least one of the first gripping means for gripping the stem and the second gripping means for gripping the root plug is displaceable in relation to the other of said gripping means along a displacement axis being parallel to, or representing, an intended longitudinal axis of a stem of a plant when the plant handling tool is in position for gripping a plant.

3.A plant handling tool according to claim 1, wherein the first gripping means is displaceable along the displacement axis in relation to the second gripping means, the first gripping means being positionable at least in a first position, below the second gripping means along said displacement axis, and at least one second position, above the second gripping means along said displacement axis.

4.A plant handling tool according to claim 2, characterised in that the first gripping means is displaceable from said first position to said second position, and vice versa, while maintain the grip of a stem of a plant.

5.A plant handling tool according to any one of the claims 1-3, characterised in the first gripping means comprising grip elements, such as jaws, for gripping a stem of a plant.

6.A plant handling tool according to claim 4, characterised in the jaws being formed by, and/or provided with a layer of, a resilient material to provide friction against the grip elements slipping along the stem of a plant while gripping the stem.

7.A plant handling tool according to any one of the claims 1-5, characterised in the second gripping means comprising arc shaped grip elements for gripping the root plug of a plant. lOA plant handling tool according to any one of the claims 4-6, the first and/or second gripping means comprising replaceable grip elements adaptable to different types of plants to be gripped.

8.A plant handling tool according to any one of the claims 4-7, characterised in at least one actuator being configured to control grip elements of the first gripping means, and grip elements of the second gripping means, the at least one actuator controlling one or more mechanical linkages connecting the at least one actuator to the grip elements..

9.A plant handling tool according to any one of the preceding claims, characterised in an actuator controlling the displacement of the first and/or second gripping means in relation to the other of said gripping means.

10.A plant handling tool according to claim 9, wherein the first and/or secondgripping means is configured to be displaced by the actuator rotating a threaded shaft, the first and/or second gripping means being rotationally fixed in relation to the threaded shaft and comprising a hole portion provided with an internal thread that cooperates with the threads of the threaded shaft to run along the shaft through rotation of the shaft.

11.A system comprising: a plant handling tool according to any of the claims 1-10, a location for storing plants to be gripped by the plant handling tool, receiving means for receiving a plant when being released by the plant handling tool following the plant being gripped by the plant handling tool, plant handling tool manoeuvring means, such as a robotic arm, carrying the plant handling tool, and being configured to manoeuvre the plant handling tool to the location for storing plants and, following gripping of a plant, manoeuvre the plant handling tool to the receiving means and release the plant by releasing the grip.

12.A system according to claim 11, further being configured to, when gripping a plant: manoeuvre the plant handling tool to a position allowing the stem to be lO gripped by the stem gripping means, grip the stem through the use of the first gripping means, displace the first gripping means in relation to the second gripping such that thereby the gripped plant is displaced in relation to the second gripping means to allow the root gripping means to grip the root plug of the plant, and grip the root plug of the plant by the root gripping means..

13.A system according to claim 11 or 12, further being configured to when releasing a plant: releasing the grip of the second gripping means followed by releasing the grip of the first gripping means, or releasing the grip of the first and second gripping means simultaneously.

14.A planter comprising: a system according to any one of the claims 11-13, and means for planting a released plant received by the receiving means.

15.A planter according to claim 14, further being configured to receive one or more trays comprising plants, the planter further being configured to manoeuvre the plant handling tool to grip a plant from the one or more trays and release picked plants and release picked plants at a position for releasing the plant to be received by the receiving means for transplantation or further transportation.

16.A method for gripping a plant having a stem and a root plug through the use of a plant handling tool comprising: first gripping means for gripping the stem of a plant; and second gripping means for gripping a root plug of the plant; the method comprising: gripping the stem of a plant through the use of the first gripping means; displacing the first gripping means and/or the second gripping means in relation to the other of said gripping means along an axis being parallel to or representing an intended longitudinal axis of a stem of the plant while maintaining the grip of the first gripping means;gripping the root plug of the plant through the use of the second gripping means.

17. Computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method according to c|aim

18. Computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the method according to c|aim 16.