Apparatus and method for placing plant cuttings and cutting holding unit for planting cuttings in a cultivation medium

The present invention relates to an apparatus for placing cuttings of plants in a cultivation medium. The apparatus has a cuttings supply system for supplying a plurality of cuttings, a camera system for identifying cuttings among the plurality of cuttings that are suitable for individual pick up using pattern recognition, a pick-up tool for picking up cuttings identified by the camera system, and a planting system for simultaneously planting multiple cuttings in the cultivation medium. The planting system and the pick-up tool are separate entities. Furthermore, the pick-up tool is arranged for suitably placing picked-up cuttings in the planting system.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus for placing cuttings of plants in a cultivation medium. The invention further relates to a method of placing cuttings of plants in a cultivation medium as well as to a computer readable medium having computer readable instructions stored thereon for performing, when executed by a processor, such a method. The invention also relates to a cutting holding unit for planting cuttings in a cultivation medium. Furthermore, the invention relates to an apparatus for placing cuttings of plants in a cultivation medium comprising such cutting holding unit. Finally, the invention relates to a method of placing cuttings of plants in a cultivation unit using such a cutting holding unit.

2. Description of the Related Art

Nowadays, placing plant cuttings in a cultivation medium is often still done manually. Besides being time consuming, each individual person plants the cuttings in a slightly different way. Furthermore, the position and orientation of the placed cuttings may vary widely as well. As a result, besides being expensive, the propagation success rate of the cuttings is relatively unreliable.

International application WO03/022034 describes a method and apparatus for collecting cuttings from a conveyor belt and placing these cuttings in pots. The apparatus includes a pick and place tool for picking and placing plant cuttings. The tool includes an array of actuable pick-up means for picking up the cuttings and retaining these cuttings with a predetermined orientation relative to the tool. The tool furthermore comprises an array of elongated means for providing indentations in the pots. The method and apparatus provide an automatic method for picking up cuttings and placing these cuttings in pots.

However, the method and apparatus described in WO03/022034 have several disadvantages. For example, the apparatus and method described in WO03/022034 lead to a cutting placement having insufficient uniformity. Although the cuttings are said to be picked up with a predetermined orientation relative to the tool, the sequential picking of adjacent cuttings may cause the orientation of the picked cuttings with respect to the tool to change due to interaction with each other, in particular during the picking process. As a result, some cuttings are placed into the pots with an orientation different from the predetermined orientation, which results in a poorly placed cutting.

Furthermore, the arrangement and functionality of the pick and place tool causes the apparatus to operate with a limited throughput, i.e. the number of cuttings that can be placed within a specific period of time is limited.

European patent application 1829446 describes an assembly for placing cuttings in plant plugs in which individual cuttings are gripped by one of the arms of a rotating device by means of under-pressure. The cuttings are then transferred to a belt provided with grippers. This transfer movement takes place continually and in a rotating manner.

However, the assembly described in EP1829446 has several disadvantages. First, the use of a rotating device for picking individual cuttings occupies a lot of space. Furthermore, the throughput of the assembly is sensitive to logistics failure. The cuttings need to be supplied individually with a spacing between subsequent cuttings that is between very strict boundaries. For example, if the subsequent cuttings are supplied too close together, either one of the cuttings is not processed, or the rotating speed of the rotating device should be adapted, i.e. increased, to allow pick up of both cuttings. The first option would decrease the throughput, whereas the second option causes the control of the rotating device to be complex.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide an alternative apparatus and method for placing plant cuttings in a cultivation medium with an improved performance, in particular with respect to throughput, precision and reliability. For this purpose, an embodiment of the invention provides an apparatus for placing cuttings of plants in a cultivation medium comprising: a cuttings supply system for supplying a plurality of cuttings; a camera system for identifying cuttings among the plurality of cuttings provided by the supply system that are suitable for individual pick up using pattern recognition; a pick-up tool for picking up cuttings identified by the camera system among the plurality of cuttings; and a planting system for simultaneously planting multiple cuttings in the cultivation medium; wherein the planting system and the pick-up tool are separate entities, and wherein the pick-up tool is arranged for suitably placing picked-up cuttings in the planting system. The use of a separate pick-up tool and planting system increases the throughput of the apparatus. While the planting tool plants one or more cuttings, the pick-up tool may already pick up new cuttings to be planted. Furthermore, simultaneously planting multiple cuttings in the cultivation medium further improves the throughput.

The planting system may comprise a planting unit for accommodating multiple cuttings in a predetermined orientation; and an indentation unit for indenting the cultivation medium before planting such that the planting unit can plant the multiple cuttings in corresponding indentations in the cultivation medium made by the indentation unit. The use of a planting unit and an indentation unit allows for planting cuttings in preformed indentations. As the indentations are made with the same system, their characteristics are known and placement of cuttings can be executed even more reliably. The planting system may comprise a frame to which the planting unit and the indentation unit are both connected. Using such frame improves the knowledge of the characteristics of the indentations and may further improve the reliability and uniformity of cutting placement.

In some embodiments, the planting system comprises a plurality of cutting clamps for clamping a portion of the cuttings at a clamping position. The pick-up tool is then arranged to place gripped cuttings in the cutting clamps such that the distance between the clamping position and a cutting end to be planted in the cultivation medium is substantially the same for each cutting. Due to the clamping at the same position with respect to the end of the cutting the depth of placement within the cultivation medium is about the same for all cuttings.

In some embodiments, the cuttings supply system comprises an irregularly moveable surface for supporting the supplied cuttings. The use of an irregularly moveable surface may improve the spreading of the cuttings, which alleviates the identification and pick-up of individual cuttings among the plurality of cuttings. The irregularly moveable surface may be moveable in dependence of one or more images obtained with the camera system. On the basis of the actual placement and orientation of cuttings in the supply system a movement program may be executed for controlling movement of the irregularly moveable surface.

Embodiments of the invention further relate to a method of placing cuttings of plants in a cultivation medium comprising: providing a plurality of cuttings via a cuttings supply system; identifying individual cuttings among the plurality of cuttings that are suitable for individual pick up by means of a camera system using pattern recognition; picking up an identified cutting with a pick-up tool and suitably placing the picked up cutting into a planting system; repeating the picking up and suitably placing until a predetermined number of cuttings is suitably placed in the planting system; and planting the placed cuttings in the cultivation medium with the planting system.

In some embodiments, the method further comprises indenting the cultivation medium. The placed cuttings are then planted in corresponding indentations within the cultivation medium. A suitable way of supplying the cultivation medium is the supply via a conveyor belt.

Embodiments of the invention further relate to a computer readable medium having computer readable instructions stored thereon for performing, when executed by a processor, a method of placing cuttings of plants in a cultivation medium as described above.

It is another object of the invention to enable automatic planting of cuttings in a cultivation medium with sufficient accuracy and throughput. For this purpose, the invention provides a cutting holding unit for planting cuttings in a cultivation medium comprising: a cutting clamp comprising two opposing members for clamping a portion of a cutting at a clamping position; and a holding device comprising two opposing members for supporting the cutting at a position closer to the cutting end that is to be put into the cultivation medium than the clamping position; wherein the cutting clamp and the holding device are connected to each other such that the opposing members of the holding device and the cutting clamp are moveable towards and away of each other simultaneously, and such that the distance between the opposing members of the cutting clamp and the opposing members of the holding device is variable. Each of the two opposing members of the cutting clamp may be provided with a substantially flat surface facing each other. Such surfaces limit the chance that cuttings are damaged during clamping.

In some embodiments, the holding device takes the form of a bend limiting element for limiting the degrees of freedom of the cutting while being clamped by the cutting clamp, the two opposing members of the bend limiting element being shaped in such a way that in a position at which the two members contact each other a hole is available between the two members. The cutting clamp may be moveable with respect to the bend limiting element.

In some other embodiments, the opposing members of the holding device are moveable towards and away from each other independently of the opposing members of the cutting clamp by variation of the distance between the opposing members of the holding device and the cutting clamp. The holding device may then take the form of a bent leaf spring, the two ends of which form the two opposing members. The leaf spring ends of the bent leaf spring may be moveable with respect to the cutting clamp by connection to an actuator-driven member.

Some embodiments of the invention further relate to an apparatus for placing cuttings of plants in a cultivation medium comprising: a cuttings supply system; a camera system for identifying cuttings provided by the supply system that are suitable for individual pick up; a pick-up tool for picking up cuttings identified by the camera system; and a planting system for planting cuttings in the cultivation medium; wherein the planting system comprises one or more cutting holding units as described above. The planting system and the pick-up tool may be separate entities, and the pick-up tool may be arranged for suitably placing picked-up cuttings in the one or more cutting holding units. The use of a pick-up tool that is separate from the planting system allows for an improved throughput. The planting system may further comprise an indentation unit for indenting the cultivation medium before planting such that the one or more cutting holding units can plant cuttings in indentations in the cultivation medium made by the indentation unit. The planting system may further comprise a frame to which the one or more cutting holding units and the indentation unit are connected.

In some embodiments of the apparatus, the pick-up tool is arranged to place picked cuttings in the cutting clamps of the one or more cutting holding units such that the distance between the clamping position and the cutting end to be put in the cultivation medium is substantially the same for each cutting.

Some embodiments of the invention relate to a method of placing cuttings of plants in a cultivation medium comprising: providing one or more cutting holding units as described above; suitably placing cuttings into the one or more cutting holding units; and planting the placed cuttings in the cultivation medium. The method may further comprise indenting the cultivation medium. The placed cuttings are then planted in the indentations within the cultivation medium.

In some embodiments of the method suitably placing comprises placing picked cuttings in the cutting clamps of the cutting holding units such that the distance between the clamping position and a cutting end to be put in the cultivation medium is substantially the same for each cutting.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following is a description of various embodiments of the invention, given by way of example only and with reference to the drawings.

FIG. 1schematically shows an apparatus1for placing cuttings of plants in a cultivation medium.FIG. 2shows a schematic cross-section of a portion of the apparatus ofFIG. 1. The basic components of the apparatus1will be discussed with reference toFIGS. 1 and 2.

The plant cuttings may be cuttings of any sort, and may include cuttings having a stem and one or more leafs, further referred to as stem cuttings, cuttings predominantly consisting of leafs, further referred to as leaf cuttings, as well as cuttings having a turnip further referred to as turnip cuttings. Examples of stem cuttings include, but are not limited to, cuttings of chrysanthemum, Christmas star, boxwood, flamingo flower (‘anthurium’), and panda plant (‘kalanchoe’). Examples of leaf cuttings include, but are not limited to, cuttings of crab cactuse, and conifer. Examples of turnip cuttings include, but are not limited to cuttings of cranesbill (‘geranium’).

The apparatus1comprises a cuttings supply system10for supplying a plurality of cuttings. The cuttings supply system10may comprise a cutting inlet for enabling a supply of cuttings to the cuttings supply system. Alternatively, the cuttings may be inserted into the cuttings supply system10via the open top, either manually by a human operator or automatically, for example via a conveyor belt.

Preferably, the cuttings supply system10takes the form of a container having side walls12and a bottom14. The bottom14supports the cuttings whereas the side walls12ensure that cuttings are kept within the container. A container occupies little space, which makes the apparatus1compact. Additionally, movement and/or installment of the apparatus1may be easy as well.

The apparatus further comprises a camera system20(only shown inFIG. 2) for identifying cuttings among the plurality of cuttings provided by the supply system10that are suitable for individual pick up. The camera system20comprises one or more cameras22. Based on images obtained with the one or more cameras22cuttings that are suitable for individual pick up are identified using pattern recognition techniques. For example, in case of stem cuttings, the camera system20may be arranged to identify individual stems based on the recognition of a pattern corresponding to an individual stem of a stem cutting lying on the bottom of the cuttings supply system. The images provided by the camera system20may be any type of suitable image including 2-dimensional images and 3-dimensional images. In case of 3-dimensional imaging, the camera system20generally includes more than one camera22.

The apparatus further comprises a pick-up tool30. The pick-up tool30is communicatively coupled to the camera system20as is schematically shown inFIG. 2. The pick-up tool30is arranged for picking up cuttings identified by the camera system20among the plurality of cuttings and suitably placing picked-up cuttings in a planting system40.

Preferably, the pick-up tool30is provided with one or more gripping arrangements, each gripping arrangement comprising one or more grippers. The term gripper should be understood to include any type of gripper including but not limited to mechanical grippers and suction cups. Further details with respect to grippers that may be used in embodiments of the invention will be discussed with reference toFIGS. 4a-4c.

The pick-up tool30may comprise a robot arm32with sufficient degrees of freedom to enable suitable placement of picked-up cuttings in the planting system40. In some applications a robot arm32having 4 degrees of freedom, i.e. 3 rotation axes, where one axis is arranged to allow transfer along the axis (preferably in a direction substantially perpendicular to the bottom surface of the cuttings supply system) is sufficient. In some other applications a more sophisticated robot arm32is needed, for example a robot arm32capable of picking up cuttings in all kinds of three-dimensional (3D) orientations using 3D-images. Such more sophisticated robot arm32may be arranged to operate with 6 degrees of freedom.

The robot arm32is programmed to move the one or more grippers towards a suitable cutting on the bottom surface14of the cuttings supply system10, and to bring the gripper in a suitable gripping position. For this purpose, the cutting position (for example using x,y-coordinates as will be understood by a person skilled in the art) and the orientation of the cutting are used as input, where these parameters are obtained using the camera system20. Starting from this gripping position the gripper is arranged to perform a predetermined gripping action.

The planting system40is arranged for simultaneously planting multiple cuttings in a cultivation medium. The pick-up tool30may move back and forth between the cuttings supply system10and the planting system40to provide the multiple cuttings that are to be planted simultaneously. The planting system40may include a planting unit42and/or an indentation unit44. The planting unit42is arranged to accommodate multiple cuttings in a predetermined orientation. The indentation unit44is arranged for indenting the cultivation medium, i.e. it makes holes of suitable size and shape to accommodate a cutting to be planted. The indentation unit44is arranged to indent the cultivation medium before the planting unit plants the cuttings in indentations made with the indentation unit. The planting unit42and the indentation unit44may be rigidly connected to each other, for example by connection to a common frame, to simplify alignment of the holes made in the cultivation medium and the components within the planting unit to arrange the planting of the cuttings.

The apparatus1may further comprise a cultivation medium supply unit50for supplying the cultivation medium. The cultivation medium may be provided in a predefined format, for example in the form of soil cubes with suitable dimensions (e.g. length×width×height of 40 mm×40 mm×30 mm). The cultivation medium may be any medium suitable for cultivating cuttings. Examples of suitable cultivation media include but are not limited to a soil block, a soil cube, rock wool, and flower soil.

The cultivation medium supply unit50preferably takes the form of a conveyor belt52. The conveyor belt52may then be aligned with the indentation unit44and the planting unit42. In some embodiments, such alignment means that the conveyor belt52transfers a portion of the cultivation medium that is indented by the indentation unit44towards a position at which the planting unit42can place a cutting in the hole made in the cultivation medium.

The side walls12and the bottom14may be rigid. Alternatively, at least one side wall12may be at least partially permeable. For example, in the embodiment shown inFIG. 2, the left side wall12ais formed by a plurality of brushes13. The brushes13may brush off debris from the picking tool30. In particular, the robot arm32of the pick-up tool30may move the grippers through the brushes to clean the grippers after placement of cuttings in the planting system40.

The bottom14may, at least partially, moveable. For example, as schematically shown inFIG. 2, at least a portion of the bottom14may be formed by a portion of a conveyor belt16. In some particular embodiments the bottom surface for supporting the cuttings is an irregularly moveable surface. Further details with respect to the irregularly moveable surface will be discussed with reference toFIGS. 3a,3b.

FIG. 3ashows an elevated view of a portion of the cuttings supply system10ofFIG. 1. In particular,FIG. 3ashows a side wall12of the container11provided with an actuator16for creating surface movement in a direction substantially perpendicular to the bottom surface14of the container11, i.e. to create movement in a z-direction when the surface lies in an x-y plane. The actuated movement in the z-direction is preferably a non-linear movement.

FIG. 3bschematically shows the z-direction movement actuation mechanism used to obtain non-linear movement of the bottom surface in a direction substantially perpendicular thereto. In the mechanism shown inFIG. 2a driving unit, e.g. an electromotor, is arranged to drive a drive axis17into a rotational motion. The drive axis17is connected to a bottom surface actuating structure18, in this example a bar of which only a cross-section is shown. The actuating structure18may extend underneath the entire width of the bottom surface. By connecting the drive axis17and the actuating structure18with a rigid connection unit19, the rotational motion of the drive axis17is converted into a movement of the actuating structure18in a direction substantially perpendicular to the bottom surface14of the container, i.e. the z-direction. As a result of the movement in the z-direction, cuttings are “shaken” and can spread out over the surface. The movement may further improve disentanglement of entangled cuttings to obtain individual cuttings suitable for planting. Note that further irregularity in the movement of the bottom surface may be obtained by using a drive axis with a non-circular cross-section, for example an elliptical cross-section.

In addition to movement in the z-direction, movements of the irregularly moveable surface may include one or more predefined in-plane movements of the complete surface. For example, as shown inFIG. 2, the entire surface is part of a conveyor belt that is moveable towards and away from the planting system (denoted with X-direction and −X-direction respectively).

By combining movement of the bottom surface14in an in-plane direction, and driving the actuator16to create movement of the bottom surface14in a direction substantially perpendicular thereto, irregular movement can be created in a controllable fashion. As a result of the irregular movements in both in-plane and z-directions, disentanglement of cuttings improves further, which further enhances the development of a plurality of individual cuttings within the cuttings supply system10.

Both the surface movements and temporary surface deformations may be controllable with a control unit. The control unit can take the form of a computer or any other suitable control device known to those skilled in the art. The control unit may be instructed to execute a program. In particular, the control unit may be communicatively coupled to the camera system20, and arranged to execute a movement program to be applied to the irregularly moveable surface in dependence of one or more images obtained with the camera system. If the camera system20cannot detect sufficient individual cuttings on the irregularly moveable surface, the camera system may instruct the control unit to execute the movement program.

The movement program contains computer readable instructions that may be stored on a computer readable medium. The computer readable medium having the movement program stored thereon may be provided to the control unit to perform, when executed by a processor in the control unit, the movement program for controllably moving the irregularly moveable surface as described above.

FIGS. 4a-4cshow different views of an embodiment of a pick-up tool30. The pick-up tool30comprises one or more gripping arrangements34arranged for picking up cuttings among the plurality of cuttings. In the embodiment ofFIGS. 4a-4cthe pick-up tool30comprises four gripping arrangements34. The shown gripping arrangements34are particularly suitable for the picking up of stem cuttings. Stem cuttings typically include a stem portion with an end that serves as a basis for roots to be formed, and a leaf portion arranged for developing plant elements such as leafs, buds and flowers.

The gripping arrangements34comprise two grippers34a,34b. The grippers34aare parallel grippers. The grippers34bare angled grippers. Each gripper34a,34bcomprises two gripping units that can move in opposing directions with respect to each other. A first gripper34acomprises two opposing flattened gripping units arranged to grip a stem portion of a cutting. The gripping units move parallel with respect to each other. The first grippers34aare arranged to grip the cuttings at a specific gripping position. By using the camera system20a suitable gripping position may be defined for each cutting. For example, the camera system20may define an individual cutting as a cutting for which it can identify a stem portion including the end of the stem portion. The gripping position may then be with respect to the stem portion end. An available first gripper34amay then pick-up the identified cutting at the defined gripping position, for example a position within the stem portion that is located at a predefined distance from the stem portion end. Preferably, the pick-up tool30picks up four cuttings, i.e. each gripper34holding a cutting, before moving towards the planting system40for further handling.

The second gripper34balso comprise two opposing gripping units that can move in opposing directions with respect to each other. In this case, the gripping units rotate towards and away from each other. In closed position, the gripping units of the second grippers34bcontact each other while leaving a central area open. In the case of the grippers34bofFIG. 4bthis open area is substantially circular in shape.

Preferably, the grippers34can be operated separately. In some embodiments the first gripper34aand the second gripper34bof the same gripper arrangement34are operated simultaneously with respect to their closed and open state, i.e. a gripping state and a non-gripping state respectively. In some other embodiments, opening and closing of the first gripper34ais independent from opening and closing the second gripper34b.

The gripping arrangements34of the pick-up tool30ofFIGS. 4a-4cmay operate in the following way in case the cuttings are stem cuttings. First, the robot arm32moves the pick-up tool30towards an identified single cutting on the basis of information obtained with the camera system20. The grippers34a,34bof the gripping arrangements34are in an open state, i.e. a state unsuitable for gripping cuttings.FIG. 4bshows the gripping arrangements34in an open state. The pick-up tool30then picks up the cutting at a suitable gripping position with the first gripper34aof the gripping arrangement34. As a result the stem portion of the cutting is clamped by the first gripper34a. Then a next cutting may be picked up by a first gripper34aof the next gripping arrangement in a similar way as described above. The picking up of cuttings may continue until all first grippers34ahave picked up a cutting, i.e. in this case after the pick-up of four cuttings.

Subsequently, the second grippers34bof the gripping arrangements34close as well, either simultaneously or a short period after the each other. The open central area within the second gripper34bencloses the leaf portion and supports the cutting so that it does not rotate about the gripping position. The second grippers34bthen may be moved away from the first grippers34ain a direction substantially parallel to the orientation of the cutting, schematically denoted by the arrow36inFIG. 4C. While moving away from the first gripper34athe second gripper34bforces the leaves in an orientation facing away from the stem portion. As a result of this orientation blockage by leaves in subsequent process steps, e.g. during planting, is avoided, which improves the reliability of the cutting planting process.

Note that different schemes of operation of the first grippers34aand the second grippers34bmay be possible as well.

Generally, the pick-up tool30assumes that the bottom surface of the cuttings supply system10is at substantially the same level throughout the supply system10. However, to ensure that local deviations from such average level do not jeopardize the performance of the gripping arrangements34, each gripping arrangement34or the pick-up tool30may be provided with a surface detection sensor. In such case, the gripper action may involve approaching the cutting, and activate gripping upon detection of the surface. Alternatively, the robot arm32may place the pick-up tool30so close to the bottom surface14that the maximum distance over which the gripping arrangement34can move to approach the cutting is always sufficient to hit the surface. For example, if the gripping arrangement34can move over 40 mm, and the distance in the direction of gripper movement between the gripping arrangements34and the average level of the cutting supporting bottom14is set to 35 mm, the gripping arrangement34will always be able to pick-up the cutting.

FIG. 5shows a planting system that may be used in embodiments of the invention. The planting system comprises a planting unit42. The planting unit42comprises a number of cutting holding units80for holding cuttings in a predefined orientation. The planting system40ofFIG. 5comprises eight cutting holding units80. If cooperating with the pick-up tool30shown in and described with reference toFIGS. 4a-4c, the pick-up tool30places two times four cuttings in the planting system40before planting is executed. The predefined orientation in the embodiment ofFIG. 5is a substantially horizontal orientation.

The planting unit42is coupled to a rotation mechanism43which is arranged to bring the planting unit42into an orientation suitable for the planting of cuttings. In the planting orientation, the orientation of the cuttings is a substantially vertical orientation with the stem portion facing downwards. So, after being provided with sufficient cuttings by the pick-up tool30, the cutting holding units80are rotated towards the planting orientation and the planting unit42is moved down for planting. Further details with respect to the cutting holding units80will be discussed with reference toFIG. 6.

The planting system40ofFIG. 5further comprises an indentation unit44. The indentation unit is arranged for indenting the cultivation medium before planting such that the planting unit42can plant cuttings in indentation in the cultivation medium made by the indentation unit. The use of an indentation unit44simplifies the planting of cuttings. The planting of cuttings can be done with less force, which reduces the risk of damaging the cuttings during planting. Furthermore, in particular if indenting is executed in a uniform way, the cuttings are more easily placed with a uniform orientation.

The planting system40ofFIG. 5comprises a frame46to which both the planting unit42and the indentation unit44are connected in a defined way. Consequently, the planting as performed by means of the planting unit42can be adjusted very precisely in view of specific operational details of the indentation unit44. Consequently, the reliability of cutting placement may be improved further.

FIG. 6schematically shows a cutting holding unit80that may be used in embodiments of the invention. The cutting holding unit80ofFIG. 6comprises a cutting clamp81and a bend limiting element83. The cutting clamp81is arranged to clamp the cutting at a clamping position, and may take the form of two opposing clamping elements provided with a flat clamping surface portion82. The bend limiting element83is arranged to limit the degrees of freedom of the cutting while being clamped by the cutting clamp81. The bend limiting element83comprises two opposing portions that can move away from and towards each other. The portions are shaped in such a way that in a closed position, i.e. a position at which the two portion contact each other, a hole84is available between the two portions. The hole is dimensioned in such a way that at least the stem of a cutting fits through the hole84.

The two opposing elements of the cutting clamp81and the two opposing portions of the bend limiting element83can be moved away from and towards each other via rods86a,86bas schematically denoted by arrow85. In addition, the cutting clamp81can be moved towards and away from the bend limiting element83, schematically denoted by arrow87. The operation of the cutting holding element80ofFIG. 6during the planting operation will be discussed with reference toFIGS. 7a-7f.

As discussed with reference toFIGS. 4a-4c, in some embodiments, the pick-up tool30is arranged to place gripped cuttings in the planting system40so that the clamping position of the cuttings placed in the planting unit is substantially the same for all cuttings. In case of the use of the cutting holding unit80ofFIG. 6this means that the pick-up tool30is arranged to place each cutting in a suitable cutting holding unit80so that the stem portion extending from the bend limiting element83in a direction away from the cutting clamp81is substantially the same for all cuttings. Typically, the length of the extended portion is about 5-20 mm, preferably 7-15 mm. Having the same clamping position makes the cutting placement in the cultivation medium more uniform. During planting all cuttings are planted at substantially the same depth as the plant depth of each cutting is limited by the bend limiting element being at the same height as the top layer of the cultivation medium in which the respective cutting is placed. An improved uniformity of the depth of planting improves the controllability of the cutting placement process, and makes the process more reliable.

The pick-up tool30may use one or more images obtained with the camera system20to determine at what position a specific individual cutting should be picked up to enable suitable placement in the planting unit. Determining the desired position of pick-up can be done by analysis using pattern recognition algorithms known to those skilled in the art.

FIGS. 7a-7fschematically show a possible way of planting a cutting with the cutting holding unit80ofFIG. 6.FIG. 7aschematically shows a side view of a cutting holding unit80before cutting placement by the pick-up tool. Although not visible inFIG. 7a, both the cutting clamp81and the bend limiting element83are arranged in a position suitable for receipt of a cutting.FIG. 7bshows the same cutting holding unit80including a suitable placed cutting90. InFIG. 7bthe cutting90is clamped by the clamp81while the stem portion of the cutting92penetrates through the hole of bend limiting element83. As explained earlier, the cutting leafs94are oriented such that they do not interfere with the clamping.

Preferably when all cutting holding units are occupied with cuttings, the cuttings can be planted by a sequence of moves schematically shown inFIGS. 7c-7f. First, as shown inFIG. 7c, the clamp81is moved away from the bend limiting element83, schematically denoted by the arrow. As a result, the cutting90moves in the same direction. This may result in the stem portion end to be withdrawn out of the hole in the bend limiting element83as shown inFIG. 7c.

After retraction of the clamp81the holding unit80is rotated towards a substantially vertical orientation, for example by using a mechanism43as shown inFIG. 5. The combined retractions and rotation movement shown inFIGS. 7cand 7dreduces the risk that the stem portion end of the cutting90is damaged by the rotation towards the orientation suitable for planting. Preferably, as shown inFIG. 7d, a cultivation unit95provided with an indentation96is suitably placed underneath the holding unit80for planting purposes.

If needed, not shown inFIGS. 7a-7f, the planting unit40as a whole moves towards the cultivation medium95to allow for continuation of the planting sequence. Preferably, the height of the cultivation medium is known, so that the position of the planting system with respect to the cultivation medium is the same for all cuttings to be planted. This may be done by supplying units of cultivation medium having a fixed height. Alternatively, the height of the cultivation medium and may be measured by means known to the person skilled in the art and then adjusted to align with a predetermined height used by the planting system as its cultivation medium reference height.

When the holding unit80is suitably aligned with the cultivation medium95, the clamp81is moved towards the bend limiting element83as shown inFIG. 7e. The distance over which the clamp81is moved is typically larger than the distance moved in the action shown inFIG. 7c. For example, the clamp81may move about 10 mm away from the bend limiting element83inFIG. 7c, while it moves about 20 mm towards the bend limiting element inFIG. 7e. By moving the clamp81towards the bend limiting element83, the cutting90enters the indentation96in the cultivation medium. As the stem portion92of the cutting90moves through the hole in the bend limiting element83, the insertion of the cutting90is performed in a guided fashion. The combined use of the bend limiting element83and the cutting clamp81ensures that cuttings90can be placed in a substantially upright position. Furthermore, contact between cuttings held by adjacent cutting holding units80is avoided, which improves the reliability of cutting placement.

Finally, the cutting holding unit80releases the cutting90, as schematically shown inFIG. 7f. Releasing the cutting includes the opening of the cutting clamp81and the bend limiting element83combined with retraction of the cutting holding unit80away from the cultivation medium95. Preferably, as shown inFIG. 7f, the cultivation medium95with the cutting placed therein is moved away from the cutting holding unit80while the cutting holding unit80is slightly tilted. This way of release has the advantage that the risk of pulling back and/or damaging the cutting90is reduced.

FIGS. 8a-8bshow another embodiment of a cutting holding unit100that may be used in embodiments of the invention. The cutting holding unit100comprises a cutting clamp101and a holding device105. The cutting clamp101is similar in nature to the cutting clamp81of the cutting holding unit80inFIG. 6. The cutting clamp101is arranged to clamp the cutting at the clamping position and comprises two opposing clamping members103provided with a flat clamping surface portion102.

The holding device105comprises two opposing holding members, and is arranged to hold the cutting at a position closer to the end of its stem portion than the clamp101. In the embodiment ofFIGS. 8a, 8b, the holding device105takes the form of a bent leaf spring106in which the ends of the leaf spring106form the two opposing surfaces107. Of course, different alternatives for the holding device105may be used as well, for example two opposing leaf springs instead of a single one that is bent in a predefined way.

The distance between the two opposing holding member surfaces107of the holding device105and the opposing surface portions102of the cutting clamp101is variable. For example, in the embodiment ofFIGS. 8a, 8b, the center portion of the bent leaf spring106is connected to an actuator-driven member110that can move the holding device towards and away from the cutting clamp101. In particular, the bent leaf spring106is partially guided through the opposing members103of the cutting clamp101, the two opposing leaf spring ends107are moveable towards and away from the two opposing surface portions102. Furthermore, since the bent leaf spring106is partially guided through the opposing members103of the cutting clamps, varying the distance between the two opposing clamp surfaces102results in a similar movement of the leaf spring ends107. The ability to vary the distance between the holding device ends107and the opposing clamp surfaces102in a direction substantially parallel to the direction of the plant stem to be planted, in combination with the ability to control the opening and closing of the opposing members of the holding device105by similar movement of the clamp members103allows for very accurate and reliable planting within a limited period of time. A more detailed operation of the cutting holding element100ofFIGS. 8a,8bduring a planting process will be discussed with reference toFIGS. 9a-9d.

In some embodiments, the holding device105may exert less clamping strength on the cutting than the cutting clamp101. The clamping strength is then preferably such that the holding device105during movement towards the cutting clamp101along a trajectory stays, for at least part of the trajectory, in contact with the cutting. Eventually, the movement towards the clamp101may be such that the cutting is only clamped by the cutting clamp101.

As discussed with reference toFIGS. 4a-4c, in some embodiments, the pick-up tool30is arranged to place gripped cuttings in the planting system40so that the clamping position of the cuttings placed in the planting unit is substantially the same for all cuttings. In case of the use of the cutting holding unit100ofFIGS. 8a, 8bthis means that the pick-up tool30is arranged to place each cutting in a suitable cutting holding unit100so that the stem portion extending from the clamp101is substantially the same for all cuttings. Having the same clamping position makes the cutting placement in the cultivation medium more uniform. During planting all cuttings are planted at substantially the same depth as the plant depth of each cutting is limited by the bend limiting element being at the same height as the top layer of the cultivation medium in which the respective cutting is placed. An improved uniformity of the depth of planting improves the controllability of the cutting placement process, and makes the process more reliable.

Again, the pick-up tool30may use one or more images obtained with the camera system20to determine at what position a specific individual cutting should be picked up to enable suitable placement in the planting unit. Determining the desired position of pick-up can be done by analysis using pattern recognition algorithms known to those skilled in the art.

FIGS. 9a-9dschematically show different positions of the cutting holding unit100ofFIGS. 8a-8bduring the planting process. The movement of the planting system40with respect to the cultivation medium may be executed in a similar way as discussed with reference toFIGS. 7a-7f.

FIG. 9ashows a top view of the holding unit100in a position ready for receipt of a cutting. The actuator-driven member110connected to the holding device105is in an extended position, whereas the opposing members103of the cutting clamp101are in an open position. As a result, the two opposing ends107of the bent leaf spring106extend from the opposing surfaces102of the cutting clamp101and are also ready for receiving a cutting.

After placement of the cutting, the opposing members103of the cutting clamp101are “closed”, for example by pneumatic means, such that the opposing surfaces102and the opposing leaf spring ends107move towards each other until sufficient contact with the cutting is obtained. This position, in which the cutting clamp101and holding device105are clamping and holding the cutting respectively is shown inFIG. 9b. Note that inFIG. 9bno cutting is placed between the opposing surfaces. The position of the holding unit100shown inFIG. 9bis used while placing the cutting directly in the cultivation medium or placing it in an indentation therein. The planting operation may be executed in a similar way as discussed earlier, and may include suitably rotation of the holding unit100in a way as discussed with reference toFIG. 7d.

After placement of the cutting90, the cutting may be released in the following way. First, the actuator-driven member110is retracted, which results in a movement of the spring leaf ends107towards the cutting clamp101. As the bent leaf spring106is partially guided through the opposing members103of the cutting clamp101at positions away from the opposing surfaces102, the movement of the spring leaf ends107towards the cutting clamp101eventually also induces a movement of the opposing leaf spring ends107away from each other. Consequently, the holding device105no longer exerts a holding pressure onto the cutting, and the cutting is solely clamped by the opposing surfaces102of the cutting clamp101. The situation in which the leaf spring ends107are fully retracted, while the opposing members103of the clamp101are still in a closed position is shown, without cutting, inFIG. 9c.

Finally, the opposing clamp members103of the clamp101are moved away from each other, which results in a full release of the cutting. Such “release position” of the holding unit100is shown inFIG. 9d.

After release of the cutting, the holding unit100may move away from the cultivation medium and be prepared for accommodation of the next cutting to be planted.

The cutting holding unit100ofFIGS. 8a, 8bis particularly useful in case the stem is vulnerable for bending and/or when indentations in the cultivation medium are absent or insufficiently consistent in size and/or shape. Where the cutting holding unit80ofFIG. 6“pushes” the cutting during planting, the movement exerted on the cutting by the cutting holding unit100is induced by a “pull”-action of the holding device105in combination with the clamp101. In this embodiment, the cutting generally extends from the lower end of the holding device105only a few mm, such as for example 1, 2 or 3 mm.

A method of planting cuttings in a cultivation medium that may be used in embodiments of the apparatus discussed above may take the following form.

First a plurality of cuttings is provided via a supply system, for example a supply system as shown inFIGS. 1 and 2. A camera system then identifies individual cuttings. The identified individual cuttings are then picked by a pick-up tool and suitably placed in in a planting system. Finally, the placed cuttings are planted in the cultivation medium. The method allows for automatic placement of cuttings into a cultivation medium in a highly reliable and uniform way.

Preferably, while the cuttings are being identified and placed in the planting system indentations are made in the cultivation medium by an indentation unit. Placing the cuttings in indentations reduces the risk of damaging the cuttings during the planting process.

The apparatus for placing cuttings of plants in a cultivation medium may comprise a computer system comprising a processor with peripherals to enable operation of a method of planting cuttings as described above. The processor may be connected with one or more memory units which are arranged for storing instructions and data, one or more reading units, one or more input devices, such as a keyboard, touch screen, or mouse, and one or more output devices, for example a monitor. Further, a network Input/Output (I/O) device may be provided for a connection to the networks.

The processor may comprise several processing units functioning in parallel or controlled by one main processor, that may be located remotely from one another, possibly distributed over the local area network, as is known to persons skilled in the art. The functionality of the present invention may be accomplished by a combination of hardware and software components. Hardware components, either analogue or digital, may be present within the processor or may be present as separate circuits which are interfaced with the processor. Further it will be appreciated by persons skilled in the art that software components that are executable by the processor may be present in a memory region of the processor.

Embodiments of the method may be stored on a computer readable medium, for example a DVD or USB-stick, for performing, when executed by the processor within the cutting placement apparatus, embodiments of a method placing cuttings of plants in a cultivation medium. The stored data may take the form of a computer program, which computer program is programmed to implement an embodiment of the method when executed by the computer system after loading the computer program from the computer readable medium into the computer system.

The invention has been described by reference to certain embodiments discussed above. It will be recognized that these embodiments are susceptible to various modifications and alternative forms well known to those of skill in the art without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention, which is defined in the accompanying claims.