NL2035526B1 - Harvesting cutting and gripper head - Google Patents

Abstract

-22- ABSTRACT The present invention discloses a harvesting tool for harvesting crops attached to a petiole of 5 a plant. Such a tool may be fitted to a robot arm and comprises a gripping unit for gripping the petiole. It further comprises a cutting unit that is configured to cut the petiole that is gripped by the gripping unit. This gripping unit comprises a first drive, which is used to move the gripped petiole relative to the harvesting tool.

Description

Harvesting cutting and gripper head

TECHNICAL FIELD

[0001] The disclosed technology generally relates to technology for harvesting crops, such as tomatoes. More specifically the disclosed technology relates to a harvesting cutting and gripper head that can be attached to a robot arm.

BACKGROUND

[0002] The field of greenhouse farming has witnessed significant advancements with the introduction of picking robots capable of automating the labour-intensive task of harvesting crops. These robots offer the potential to enhance efficiency, productivity, and reduce labour

Costs.

[0003] Crops, such as tomatoes, are delicate and often have varying degrees of ripeness.

Picking robots often face challenges in handling the tomatoes gently to avoid bruising or damaging the fruit or vegetable. The lack of fine motor skills and the inability to assess the ripeness of each tomato accurately can result in suboptimal harvesting, leading to reduced yield and potential loss in quality.

[0004] As an example of one of the crops that can be used in combination with this invention, vine tomatoes are disclosed. Vine tomatoes, compared to single tomatoes, present additional challenges due to their growth patterns and the interdependence of multiple fruits on a single vine. Picking robots must navigate through dense foliage and identify clusters of ripe tomatoes within a larger plant structure. The complexity of the tomato plant makes it more difficult for robots to precisely locate and harvest individual fruits without causing damage or disrupting neighbouring tomatoes.

[0005] However, once a picking robot has successfully navigated to and identified crops to be picked, such as a cluster of tomatoes on a single petiole of the tomato plant, further problems arise. To harvest the cluster of vine tomatoes, picking robots often cut the vine tomatoes off of the plant. In determining the optimal location of the cut, the robot has to take multiple factors into account. To start, a cut that is close to the vine tomatoes ensures an aesthetically pleasing harvested crop that is ready-for-market (does not need additional trimming), with only a short portion of petiole still attached to the vine tomatoes. However, this inherently leaves a large piece of petiole still attached to the tomato plant, which may harm the tomato plant over time. Leaving large pieces of petiole attached to a plant leaves the plant vulnerable to diseases, pests, bacteria, and fungi, disrupts the natural nutrient flow within the plant, and may result into an imbalance of resource allocation within the plant. In turn, placing a cut that is too close to the node of the plant, leaving only a small piece of petiole attached to the plant, results in an aesthetically unpleasing crop and requires another separate cut to be performed on the crop-side after harvesting.

[0006] Another factor to take into account when placing a cut is whether the optimal cut location can be reached at all; the optimal cut location may be obstructed, not in sight, and/or simply not be accessible due to it laying outside the work envelope of the robot.

[0007] The present invention aims to improve the capabilities of picking robots being able to successfully navigate through vegetation and engage crops from a preferred orientation.

Further, it aims to provide a means for improving optimal cutting during harvesting of crops to avoid diseases on the plant-side and ensure aesthetically pleasing and ready-for-market products.

SUMMARY

[0008] To address at least some of the above discussed drawbacks of the prior art, there 1s proposed, according to a first aspect of the disclosure, a harvesting tool for harvesting crops attached to a petiole of a plant. The harvesting tool is preferably fitted to a robot arm. The harvesting tool comprises a gripping unit. The gripping unit allows to engage the petiole by at least partially surrounding the petiole, which allows locking the petiole. In this application the gripping unit locks onto the petiole, e.g. by providing a ring around the petiole into which the petiole is locked by surrounding the petiole.

[0009] In preferred embodiments, the gripping unit is arranged to grip the petiole. Gripping includes receiving the petiole and engaging the petiole from two generally opposing sides. To lock/grip the petiole, the robot arm or any other means for positioning the harvesting tool 1s used to bring the gripping unit in engagement with the petiole. Any means for identification of a petiole to which crops is attached, can be used. The identified petiole carries crops that are identified as suitable for harvesting.

[0010] In embodiments, the harvesting tool has a cutting unit configured to cut the petiole that is locked, preferably gripped, by the gripping unit.

[0011] According to the invention, the harvesting tool is arranged to move the locked petiole with respect to the harvesting tool. This allows, after locking the petiole, to move the petiole with respect to the harvesting tool. This allows repositioning of the harvesting tool while the petiole is already locked/gripped. In embodiments, the petiole is locked by surrounding it, e.g. by a ring, and the harvesting tool is moved using the robot arm. This allows moving the harvesting tool with respect to that locked petiole, e.g. by sliding the ring along the petiole.

[0012] In embodiments, the gripping unit comprises a drive, and the gripping unit and first drive are arranged to move the gripped petiole relative to the harvesting tool. This allows, after gripping the petiole, to move the petiole with respect to the harvesting tool. This allows repositioning of the harvesting tool with respect to the gripped petiole.

[0013] Accordingly, with the harvesting tool of the invention, a first locking, preferably gripping, location of the petiole can be identified, which is a location that e.g. can be easily reached. Subsequently, the locking, preferably gripping, location can changed by moving the harvesting tool with respect to the locked/gripped petiole. The harvesting tool can be moved closer to the node where the petiole is connected to the plant or the harvesting tool can be moved closer to the crops.

[0014] In an embodiment, the gripping unit comprises a first and a second roller. Rollers can be mounted on a bearing. The rollers can be driven to rotate. The petiole is gripped between the rollers and the harvesting tool has a drive for driving at least one of the rollers for moving the gripped petiole relative to the harvesting tool.

[0015] In an embodiment, the gripping unit comprises a first and second gripper arranged to be movable towards each other. A suitable second drive is provided in the housing of the harvesting tool. This allows opening and closing of the gripping unit to grip a petiole between respective grippers. The grippers can be rollers.

[0016] In an embodiment, the cutting unit comprises a first and second cutter. The cutters can be provided on opposing sides of the gripping unit. This allows cutting the petiole on both sides of the gripper. This allows to position the harvesting tool for locking/gripping the petiole, without having to take into account at which end the cutter is. This reduces the complexity for positioning the harvesting tool for engaging and subsequently locking/gripping the petiole. The cutting units on opposing ends of the gripping unit also allow cutting the petiole either closer to the plant or closer to the crops.

[0017] In embodiments, the harvesting tool further comprises a wrist between two housing parts. One housing part supports the gripping unit, the other housing part comprises a mount for mounting on a robot arm.

[0018] In embodiments, the harvesting tool further comprises a barrier that partly encloses the first and/or second gripper(s). The barrier extends away from the housing in a same direction as the gripping unit, the barrier being formed around the gripping unit as a protective cover thereof.

[0019] The harvesting tool of any of the embodiments of the invention can be connected to a robot arm. The robot arm allows positioning the harvesting tool with respect to the petiole.

The robot arm can bring the harvesting tool in a position that allows locking, preferably gripping, the petiole. The robot arm can be arranged to reposition the harvesting tool once the petiole 1s locked/gripped.

[0020] In embodiments, while driving the gripping unit, the harvesting tool can be repositioned. While the locking/gripping location is moved closer to the node where the petiole is connected to the stem of plant, the harvesting tool is moved closer to that location too using the robot arm. As the petiole is already locked/gripped, the harvesting tool can move through vines and leaves of the plant without losing grip of the petiole.

[0021] In embodiments while driving the gripping unit, the harvesting tool can be repositioned. While the gripping location is moved closer to the crops connected to the petiole, the harvesting tool is moved closer to that location too using the robot arm. As the petiole is already gripped, the harvesting tool can move through vines and leaves of the plant without losing grip of the petiole. In embodiments, the petiole is already cut loose from the plant. Moving the harvesting tool with the robot arm can comprise moving the harvesting tool closer to a container for collecting the crops.

[0022] To address any of the drawbacks of the prior art, a second aspect of this disclosure provides a method of harvesting crops attached to a petiole of a plant using a harvesting tool.

The harvesting tool may be fitted to a robot arm. The robot arm can position the harvesting tool with respect to the petiole.

[0023] Before cutting the crops from the petiole, the robot arm moves the harvesting tool into engagement with the petiole at a location of the petiole that can be reached. The system of robot arm and harvesting tool can identify first that has crops that is ready for being harvested and can then identity the petiole to which it is connected and can then identify where that petiole can be reached by the robot arm.

[0024] In embodiments, after positioning the harvesting tool in the vicinity of the petiole, the petiole is engaged by at least partially surrounding the petiole, which allows locking the petiole. The petiole is locked by the harvesting tool, e.g. by providing a ring around the petiole into which the petiole is locked.

[0025] In preferred embodiments, the harvesting tool is arranged to grip the petiole.

Gripping includes receiving the petiole and engaging the petiole from two generally opposing sides. The petiole is gripped by the harvesting tool that is brought into its vicinity. Any location of the petiole can be engaged, either close to the crops or close to the stem.

[0026] In embodiments, after locking or preferably gripping, the locked/gripped petiole is moved relative to the harvesting tool. During moving of the gripped petiole, the harvesting tool can be repositioned using the robot arm. Repositioning the harvesting tool can include moving the harvesting tool along the path of the locked/gripped petiole that is still connected to the stem of the plant.

[0027] Moving the locked petiole can include allowing to slide the petiole with respect to the harvesting tool, e.g. by partially surrounding the petiole. In embodiments, moving the locked petiole does not include a force on the petiole, but only receiving the petiole in a ring.

Moving the locked/gripped petiole with respect to the harvesting tool can include a regripping the petiole, driving the gripped petiole, etc. The gripping unit can have a drive coupled to grippers of the gripping unit for moving the gripped petiole.

[0028] In embodiments, moving the gripped petiole relative to the harvesting tool comprises repositing the harvesting tool towards a node where the petiole is attached to the plant. This allows gripping the petiole closer to that node attached to the plant.

[0029] In embodiments, after moving the locked/gripped petiole with respect to the harvesting tool, a cut is made on the locked/gripped petiole. This separates a part of the petiole with crops from the stem. In embodiments, the cut is made near the node where the petiole is attached to the plant. This allows severing close to the entire petiole from the plant, reducing chances of subsequent diseases.

[0030] In embodiments, after cutting the petiole, the severed petiole with crops is held/gripped by the harvesting tool. In embodiments, the petiole is cut between the gripping location and the node connected to the plant.

[0031] In embodiments, after cutting, the robot arm can reposition the harvesting tool with gripped and severed petiole away from the plant. Repositioning the harvesting tool can include moving it closer to a container for collecting crops.

[0032] The method can include moving the harvesting tool along the gripped and severed petiole in a direction towards a node where the petiole is attached to the crop. Subsequently a cut can be made, close to the crops. This can be the second cut.

[0033] In embodiments, during driving the harvesting tool towards the crops of the gripped petiole, the harvesting tool can be repositioned. The harvesting tool can be repositioned away from the plant. The harvesting tool can be repositioned towards the container. In embodiments, the method further comprises the step of moving the gripped petiole to or above a container for storing crops.

[0034] In embodiments, the first cut can be made between the gripped petiole and the node attached to the plant. The second cut can be made between the gripped petiole and the crops.

This allows cutting close to the desired location, while maintaining the gripped petiole into engagement with the harvesting tool. After a second cut, the gripped petiole can be released.

[0035] In embodiments, the method further comprises the step of making a third cut at the second location on the gripped petiole near the node where the petiole is attached to the crop.

BRIEF DESCRIPTION OF DRAWINGS

[0036] Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0037] FIG. 1 shows an example embodiment of a harvesting tool for harvesting crops;

[0038] FIG. 2 shows an example plant comprising crops that are suitable for harvesting with the harvesting tool;

[0039] FIG. 3 shows an example embodiment of a harvesting tool for harvesting crops;

[0040] FIG. 4 shows an example embodiment of a method for harvesting crops using a harvesting tool;

[0041] FIG. 5 shows an example embodiment of a harvesting tool for harvesting crops.

DETAILED DESCRIPTION OF DRAWINGS

[0042] Hereinafter, certain embodiments will be described in further detail. It should be appreciated, however, that these embodiments may not be construed as limiting the scope of protection for the present disclosure.

[0043] FIG. 1 shows an example embodiment of a harvesting tool 100. The harvesting tool allows harvesting crops attached to a petiole of a plant. Terminology used in the following paragraphs to describe plant sections and crops will be described in FIG. 2.

[0044] Harvesting tool 100 can be mounted on a picking arm, e.g. a robot arm, of a harvesting system used e.g. in greenhouses. Picking robots are capable of automating the harvesting crops, such as tomatoes. A picking robot is programmed to navigate to and identify a cluster of crops, such as tomatoes, on a single petiole of the tomato plant.

[0045] In the below, the description will focus on the harvesting tool 100. For details of the harvesting system as a whole, e.g. operating details, reference is made to NL2031985, incorporated by reference. Specifically, reference is made how to drive the harvesting system and how to drive the robot arm. Also, reference is made to positioning of the harvesting system, robot arm and harvesting tool with respect to the crops. Reference is also made to image recognition, identification of crops, determination of properties of the crops using cameras, videos and other capture device that can be present in the harvesting system or in the harvesting tool described in detail below.

[0046] Housing part 106 has a mounting device 108 that can be attached to the robot-arm of a harvesting system, preferably attached to rotating joint on the robot-arm of the harvesting system. Suitable robot arms preferably have at least 5 degrees-of-freedom, more preferably at least 6

[0047] Harvesting tool 100 comprises two housing parts 105 and 106 connected via a rotation joint 107. Housing part 105 comprises first and second grippers 102 and 103.

Housing part 105 also comprises first and second cutters 110 and 111.

[0048] Housing part 105 is rotatable with respect to housing part 106 of the harvesting tool 100. A suitable rotation drive can be housed in body 106. The drive may comprise an electromotor, gearbox, and/or a control unit. Having 4 point-of-rotation this close to the first and second grippers 102 and 103 is highly advantageous, as it allows the harvesting tool to engage with petioles that are hard to reach through surrounding vegetation.

[0049] Harvesting tool 100 comprises a gripping unit 119 that has first and second grippers 102 and 103. The gripping unit 119 is arranged to temporarily grip a section of a plant or crop. The grippers 102,103 are arranged to grip a petiole 101 of a plant. A gripped petiole 101 is shown in FIG. 1. First and second grippers 102 and 103 may grip petiole 101 on lateral positions, preferably on opposite positions of petiole 101, such that petiole 101 is temporarily constrained between first and second grippers 102 and 103.

[0050] To achieve gripping of petiole 101, first and second grippers 102 and 103 may be arranged in two configurations: an open- and a closed position. The gripping unit 119 can comprise a drive to move the grippers between the open and closed position. In the open position, second gripper 103 is positioned away from first gripper 102, such that there exists a gap between first and second grippers 102 and 103 in which petiole 101 can be received. A suitable guide or slider 112 is present to allow such operation.

[0051] Although FIG.1 shows gripping the petiole 101, the petiole can also be locked by surrounding it. Locking the petiole 101 can be additional to the gripping suing grippers 102/103.

[0052] After identifying a petiole to be locked/gripped, a (not shown) robot arm of a harvesting system moves the harvesting tool 100 with gripping unit 119 towards the petiole.

The petiole is approached with the grippers 102/103 facing the petiole. The housing part 105 with grippers 102/103 is also oriented so that the to-be-gripped petiole generally aligns with the gripped petiole 101 position shown in FIG.1. Subsequently the harvesting tool 100 is moved towards the to-be-gripped petiole so that the petiole is positioned between the opened grippers 102, 103. Subsequently the grippers 102/103 are closed.

[0053] Gripping of petiole 101 using first and second grippers 102 and 103 may happen under a predetermined force, which is preferably more than 2 N, more preferably between 2

Nand 50 N. The force that is being applied to petiole 101 may also be controlled, that is determined and adjusted in real time using sensors, such as a strain gauge, load cell, force sensing resistors, piezoelectric sensors, capacitive sensors, and/or other force measuring sensors.

[0054] Harvesting tool 100 may further comprise a sensor arranged to detect the presence and/or an orientation of petiole 101. This sensor may be arranged to detect whether petiole 101 is present in the environment of harvesting tool 100 and whether petiole 101 is in a correct orientation to be gripped. Alternatively, this sensor may be used to detect the presence and/or an orientation of petiole 101 between first and second grippers 102 and 103. This sensor may be a photocell, photoresistor, inductive sensor, ultrasonic sensor, camera, LIDAR, a strain gauge, and/or other sensor capable of detecting the presence and/or an orientation of petiole 101. Once petiole 101 has been received in the gap between first and second grippers 102 and 103, harvesting tool 100 takes on a closed position. In the closed position, second gripper 103 is positioned toward first gripper 102, such that the gap between first and second grippers 102 and 103 decreases and petiole 101 is gripped between first and second grippers 102 and 103. In the embodiment described in this paragraph, first gripper 102 is fixed and second gripper 103 is arranged to move away and toward first gripper 102. Alternatively, first gripper 102 may also be arranged to move away and towards second gripper 103, allowing first and second grippers 102 and 103 to both move away and towards each other. Vice versa, second gripper 103 may also be fixed while first gripper 102 is arranged to move away and towards second gripper 103. This type of (linear) gripping mechanism is advantageous in comparison to a rotational gripping mechanism, as it enables first and second grippers 102 and 103 to be equipped with rollers that are capable of engaging petiole 101 on exactly opposite sides, instead of (slightly) angled opposing sides. Exactly opposing rollers provide a more robust rolling motion that is compatible with petioles that are not completely straight.

[0055] Slider 112 is arranged to move first and/or second grippers 102 and 103 away and/or towards their opposing gripper. Slider 112 is attached to first and/or second grippers 102 and 103 and may comprise a linear actuator and/or any other actuator capable of moving first and/or second grippers 102 and 103 away and/or towards their opposing gripper. Slider 112 may further comprise a pneumatic or electric drive for moving second gripper 114 towards first gripper 113.

[0056] The gripped petiole 101 can be moved with respect to housing 105. To that end, the gripping unit 119 comprises a drive. The drive and gripping unit 119 are arranged to move the gripped petiole. In FIG. 1 the first and second grippers 102 and 103 may each respectively comprise and/or be attached to first and second rollers 113 and 114. Rollers 113/114 are rotatable, e.g. connected via a bearing, with respect to the housing 105 and can be connected to a suitable drive received in housing 105.

[0057] Once first and second grippers 102 and 103 have gripped petiole 101, first and second rollers 113 and 114 are configured to move petiole 101 relative to harvesting tool 100.

By actuating first and second rollers 113 and 114 and/or rolling first and second grippers 102 and 103, the gripped petiole 101 is pushed in a direction in which it is not constrained by first and second grippers 102 and 103. These directions are the two directions that are perpendicular to the harvesting tool; either in direction 117 (pointing at the crop that is attached to the petiole) or in direction 118 (pointing at the stem and/or plant that is attached to the petiole).

[0058] First and second rollers 113 and 114 may be connected to a first and second electromotor, such as a servomotor or DC motor, to rotate the rollers. First and second grippers 102 and 103 and/or first and second rollers 113 and 114 may comprise first and second engagement surfaces 115 and 116, which are the surfaces that actually engage petiole 101 during gripping and rolling. First and second engagement surfaces 115 and 116 may be coated and/or be manufactured from a material that experienced high surface friction with petiole 101, such as rubber and/or plastics. First and second engagement surfaces 115 and 116 may be curved to capable of optimally receiving, gripping, and rolling petiole 101 which commonly has a circular cross-section.

[0059] Harvesting tool 100 may be moved relative to petiole 101 using first and second rollers 113 and 114 to arrive at a preferred cutting location on petiole 101. One advantage of present harvesting tool 100 is that petiole 101 does not have to be gripped at the location at which petiole 101 needs to be cut. In principle, petiole 101 may be gripped at any random location on the petiole, after which first and second rollers 113 and 114 may move harvesting tool 100 to the preferred cut location on the petiole.

[0060] Moving the gripped petiole 101 with respect to the harvesting tool 100 may comprise any of the following steps. In embodiments, the harvesting system identifies and/or determines a preferred cutting location of the petiole. Cameras and image recognition techniques can be used.

[0061] Moving the gripped petiole 101 can comprise a combined operation of the actuated first and second rollers 113 and 114 and repositioning of the harvesting tool using the robot arm to which the harvesting tool 100 is mounted. Repositioning the harvesting tool allows moving of the harvesting tool such that a path 1s followed generally along the path of the petiole extending from the stem 206 of the plant as shown in FIG.2. In this manner the movement of the petiole 101 that is still connected to the plant is reduced.

[0062] To make an actual cut on petiole 101, harvesting tool 100 further comprises first and second cutters 110 and 111, preferably located adjacent and on opposite sides of first and second grippers 102 and 103. Once harvesting tool 100 has arrived at the preferred cutting location on the petiole, first and/or second cutters 110 and 111 may be activated to make a cut in petiole 101 on either side of first and second grippers 102 and 103.

[0063] Before cutting the locked petiole 101, the petiole 101 is gripped to ensure that the harvesting tool holds the petiole 101 after severing the petiole 101 from the plant.

[0064] FIG.3 shows the first and second cutters 110 and 111 in detail. Generally, embodiments of this disclosure show first locking, preferably gripping the petiole at a first location, moving the harvesting tool along the petiole to a second location for cutting the petiole, severing the petiole from the plant and subsequently moving the harvesting tool along the gripped petiole to a third location for cutting the crops from the remaining petiole. The first, second and third location can be different location along the petiole. As a result, part of petiole 101 can still remain gripped between first and second grippers 102 and 103, even after a cut has been made.

[0065] When harvesting tool 100 makes a cut in petiole 101 using first cutter 110, the remaining part of petiole 101, which is the part extending towards direction 117, is still gripped. Similarly, if harvesting tool 100 makes a cut in petiole 101 using second cutter 111, the remaining part of petiole 101, which is the part extending towards direction 118, is still gripped. This is advantageous, as it allows harvesting tool 100 to make two cuts in petiole 101: a first cut that may be close to the stem/plant (direction 118) and ensures that the plant stays healthy after harvesting, and a second cut that may be close to the crop (direction 117) and ensures that an aesthetically pleasing crop is harvested, that is ready-for-market, and does not need to be post-processed. This second cut may be executed when the crop attached to petiole 101 is located above a crate or container for storing crops. By repositioning the harvesting tool using the robot after severing the petiole from the plant, the harvesting tool can be positioned close to the container. The second cut results in the crops falling into the container. The remaining stem can be released and dropped on the ground, away from the container, by again repositioning the harvesting tool using the robot arm.

[0066] Besides being capable of making two cuts, it is also advantageous that harvesting tool 100 is capable of gripping the remaining part of petiole 101 gripped after making a first cut, because this allows the remaining part of severed petiole 101 — which preferably comprises the crop — to be transported to a different location before making a second cut.

After making a second cut in petiole 101, the crop is harvested and will not be gripped by harvesting tool 100 any longer and might fall. The robot arm connected to harvesting tool 100 that is gripping petiole 101 repositions the harvesting tool near or above a crate after a first cut and before cutting the crops.

[0067] After severing the petiole 101 from the plant with a first cut, multiple cuts can be performed on the petiole before cutting the crops. An advantage of multiple cuts before cutting the crops, is that the gripped petiole is made shorter than after the first cut. This makes it so that the object (petiole + crop) that has to be moved near or above the crate is smaller, making it easier to pass and avoid vegetation present within the environment.

[0068] A barrier 109 extends away from the housing of the harvesting tool. First gripper 102 extends away from the housing in the same direction and is partly enclosed by barrier 109, which ensures that it is protected from objects, such as leaves and branches, in its environment. Second gripper 103 may also be partly enclosed by a barrier. Protection against objects in the environment is needed, as these objects may get stuck in between first and second grippers 102 and 103 during gripping and/or get stuck inside first and second rollers 113 and 114 during rolling.

[0069] FIG. 2 shows an example plant 200 comprising crops that are suitable for harvesting with the harvesting tool. Plants and/or crops that may be harvested with the present invention include, but are not limited to: fruits, such as tomatoes, apples, citrus fruits, vegetables, such as zucchini’s and eggplants. In practice, the presented harvesting tool is capable of harvesting any crop that is attached to a plant by a petiole.

[0070] Example plant 200 grows tomatoes 201, which are to be harvested in clusters, also called vine tomatoes. Each tomato 201 is attached to other tomatoes in the cluster by vines 202. Each cluster of vine tomatoes is attached to a single petiole 204. The point where the vines 202 of tomatoes 201 connects to the petiole is called the crop node 203. In the case of tomatoes or other crops that are harvested in clusters, crop node 203 (where the cluster collects into a single petiole 204) is also the point at which the crop should be cut. Crop node 203 may be identified as the point where petiole 204 is first split into a vine 202 that is attached to a tomato 201, preferably anywhere within the vicinity of that point, more preferably less than 5 cm before that point.

[0071] The point at which petiole 204 connects to the rest of the plant is called petiole node 205. Plant 200, or in essence stem 206, comprises multiple petiole nodes 205, some of which connect to crops and some of which connect to leaves 205. The combination of petioles 204 and leaves 207 often make 1t so that crops, such as tomatoes 201, are hard to reach without having to either push aside objects or navigate around them. Pushing away objects, such as leaves 207 and petioles 204 can result in damage. Pushing away plant parts may be damaging to plant 200. Moreover, harvesting environments, such as greenhouses, are often limited in size, accommodate devices, and are equipped with (tension) wires that are difficult to avoid for robots. Therefore, a preferred solution for a robot is to navigate around and avoid objects.

This in turn stresses the need for solutions that include a lower required gripping accuracy, additional flexibility, and degrees of freedom to operate in a greenhouse comprising poles, frames and wires.

[0072] As was previously discussed, it is preferred to make a cut as close to crop node 203 as possible, as it results in an aesthetically-pleasing and ready-for-market product, in turn avoiding the need for any additional post-processing steps and thus reducing labour costs. It is also preferred to make a cut as close to petiole node 205 and not leave a large portion of remaining petiole 208 attached to the stem 206 of plant 200, as this leaves plant 200 susceptible to diseases, pests, bacteria, and fungi, and may disrupt the natural nutrient flow within the plant, and result into an imbalance of resource allocation within the plant. The present invention allows providing a first cut close to crop node 203 and a second cut close to petiole node 205. Also, the harvesting tool of the present invention may lock, preferably grip, the petiole at any location and move itself to the desired cutting locations. The invention allows more ways of reaching the petiole as the petiole can be gripped at different locations along the length of the petiole, not limited to the cutting positions. Even more advantageous is that the present invention allows positioning of the harvesting tool to desired cutting locations, as well as placing a first cut, while keeping the petiole gripped afterwards, thereby not having the cut-off crop fall down on the ground, which may cause damage to the crop.

[0073] FIG. 3 shows the same harvesting tool 300 for harvesting crops twice, in two orientations. Harvesting tool 300 has housing 311 that comprises first and second grippers 302 and 303, which in turn respectively comprise first and second rollers 306 and 307. First and second grippers 302 and 303 further respectively comprise engagement surfaces 308 and 309. Slider 310 is arranged to move first and/or second grippers 302 and/or 303 are away and/or towards their opposing gripper, provide force onto and grip a petiole between the first and second grippers 302 and 303.

[0074] Once harvesting tool 300 has gripped a petiole and moved harvesting tool 300 to a preferred location on the petiole using first and second rollers 306 and 307, a cut can be made using either first and/or second cutters 304 and/or 305. First and second cutters 304 and 305 each comprise a blade, preferably with a concave shape to optimally receive the petiole with a substantially circular cross section without the petiole escaping from the blade during cutting,

[0075] First and second cutters 304 and 305 are each connected to an electromotor, such as a servomotor or DC motor, that drives rotation of first and second cutters 304 and 305 toward and away from housing 311. Once rotated downward toward body 311, first and second cutters 304 and 305 may slide inside first and second slits 312 and 313 respectively. First and second slits 312 and 313 are arranged to receive first and second cutters 304 and 305, such that an object (such as a petiole) — which is presented perpendicular to first and second slits 312 and 313 — may be cut throughout its full cross section at the location of the first and second slits 312 and 313. This feature of harvesting tool 300 is advantageous, as it will ensure that a perfect cut is always made. Imperfect cuts are defined as cuts that do not fully cut an object, leaving (parts) of the object intact, and thereby having the two sides of the object remained connected to each other. Without first and second slits 312 and 313, first and second cutters 304 and 305 would merely be able to cut up to the top surface of body 311, leaving the possibility of object material being squished by the first and second cutters 304 and 305 onto the top surface of body 311. When object material is squished by a cutter, the force provided by the cutter may not be enough to cut through the squished material, thereby leaving the object partly intact. By providing first and second slits 312 and 313, no object material 1s ever squished and perfect cuts are guaranteed.

[0076] FIG. 4 shows an example embodiment of a method 400 for harvesting crops attached to a petiole of a plant using a harvesting tool.

[0077] Step 401 comprises gripping a petiole at a location on the petiole using grippers provided on the harvesting tool. The location at which the petiole is gripped by the harvesting tool in step 401 may be at any location along the length of the petiole, but is preferably a location that is (most) suitable for gripping, which may be a location that is most accessible for the harvesting tool. Accessible locations may include those that are unobstructed by leaves, branches, other petioles, and/or locations that require the least effort to reach for a robot arm that is attached to the harvesting tool. The location at which the petiole is gripped by the harvesting tool location may be gripped at any angle/orientation, again preferably being an angle/orientation that 1s most accessible to the harvesting tool and/or the robot arm that is attached to the harvesting tool.

[0078] In step 401, the petiole may be approached with the gripping unit facing the petiole.

The housing part of the harvesting tool is also oriented so that the to-be-gripped petiole generally aligns with the gripped petiole 101 position shown in FIG.1. Subsequently, the harvesting tool is moved towards the to-be-gripped petiole so that the petiole is positioned in between the gripping unit, such as the opened grippers 102 and 103 of FIG. 1. Lastly, the gripping unit is closed, after which the petiole is successfully gripped. In other embodiments, the petiole is locked by the gripping unit.

[0079] Step 402 comprises moving the harvesting tool along the gripped petiole in a direction towards a node where the petiole is attached to the plant. Moving in step 402 may comprise rotating first and second rollers of the harvesting tool such that the petiole is moved relative to the harvesting tool. In doing so, the stem of the plant may slightly bend in the direction of the harvesting tool to accommodate the movement of the petiole with respect to the harvesting tool, essentially forcing the petiole such that the harvesting tool reaches a first location near the node where the petiole is attached to the plant.

[0080] Alternatively, the harvesting tool may be repositioned relative to the petiole while rotating the first and second rollers, essentially guiding the harvesting tool to a first location on the gripped petiole near the node where the petiole is attached to the plant. To achieve this, the harvesting tool may be repositioned using the robot arm to which the harvesting tool is connected. Moving the harvesting tool to a different location along the petiole allows to reduce movement of the petiole that is still connected to the stem of the plant. The harvesting tool will move away from the initially gripped position of step 401. During step 402, the harvesting tool with gripping unit 119 moves to a position near the node where the petiole is attached to the rest of the plant. Throughout the movement of the harvesting tool with respect to the petiole, the petiole may stay gripped by the first and second grippers of the harvesting tool.

[0081] Step 403 comprises making a first cut at a first location on the gripped petiole near the node where the petiole is attached to the plant. Said first location on the petiole is near the node where the petiole is attached to the plant, preferably within 5 cm, more preferably within 2 cm, of that node. Cutting at said first location preferably comprises making a cut with the first and/or second cutters of the harvesting tool, more preferably the cutter that is closest to the node where the petiole is attached to the plant, because it leaves the remaining petiole with crop still gripped by the harvesting tool.

[0082] Step 404 comprises moving the harvesting tool along the gripped petiole in a direction towards a node where the petiole is attached to the crop. It is noted that, at this point, the remaining petiole that is gripped is no longer attached to the plant, merely to the crop, by virtue of the first cut. In step 404, the harvesting tool moves to a new location, namely to the node where the petiole is attached to the crop. Throughout said movement step, the petiole may stay gripped by the harvesting tool.

[0083] Step 404 may additionally comprise repositioning the harvesting tool with gripped petiole to a location near or above a crate for collecting crops. During this step, vegetation of the (neighbouring) plant(s) is avoided by the harvesting tool and/or the robot arm that is attached to the harvesting tool.

[0084] During step 404, additional cuts in the gripped petiole can be made, severing parts of the petiole at the side towards the plant (away from the crops). This reduces the length of the petiole.

[0085] Step 405 comprises making a second cut at a second location on the gripped petiole near the node where the petiole is attached to the crop. Said second location on the petiole is near the node where the petiole is attached to the crop, preferably within 10 cm of that node, more preferably within 5 cm of that node. Cutting at said second location preferably comprises making a cut with the first and/or second cutters of the harvesting tool. The cut may be made by the cutter that is closest to the node where the petiole is attached to the crop, resulting in the crop falling, preferably inside a container for storing crops. Alternatively, the cut may be made by the cutter that is furthest from the node where the petiole is attached to the crop, resulting in the crop staying gripped by the harvesting tool. Method 400 may then further comprise moving the gripped crop to a container and either releasing the crop from its grip or making a cut with the other cutter, thereby also releasing the crop.

[0086] Step 405 may additionally comprise repositioning the harvesting tool with gripped petiole to a location near or above a crate for collecting crops, such that, after the second cut, the crop is received by the crate. During this step, vegetation of the (neighbouring) plant(s) is avoided by the harvesting tool and/or the robot arm that is attached to the harvesting tool.

[0087] FIG. 5 shows an example embodiment of a harvesting tool 500 for harvesting crops, which has two main parts: body 501, which at least comprises first and second grippers and first and second cutters, and attachment body 502, which may be attached to a robot arm.

Body 501 is rotatable with respect to attachment body 502 around axis. The range of rotation of body 501 spans at least 135 degrees, preferably at least 180 degrees, and can rotate with any increment.

[0088] The following clauses disclose embodiments of the invention.

[0089] Clause 1. A harvesting tool for harvesting crops attached to a petiole of a plant, the harvesting tool preferably to be fitted to a robot arm, the harvesting tool comprising: - a gripping unit for locking, preferably gripping, the petiole; and - a cutting unit configured to cut the petiole that 1s locked, preferably gripped, by the gripping unit, wherein the gripping unit is arranged to move the locked, preferably gripped, petiole with respect to the harvesting tool.

[0090] Clause 2. The harvesting tool of clause 1, wherein the gripping unit comprises a first and a second roller, wherein the petiole is gripped between the rollers and the harvesting tool has a drive for driving at least one of the rollers for moving the gripped petiole relative to the harvesting tool.

[0091] Clause 3. The harvesting tool of clause 1 or 2, wherein the gripping unit comprises a first and second gripper arranged to be movable towards each other to grip a petiole in between.

[0092] Clause 4. The harvesting tool of clause 2 and 3, wherein the first and second rollers are used as first and second grippers.

[0093] Clause 5. The harvesting tool of any of the clauses 1-4, wherein the cutting unit comprises a first cutter configured to make a first cut in the petiole located on a first side of gripping unit, and a second cutter configured to make a second cut in the petiole located on a second, different side of the gripping unit, wherein the cutting unit preferably comprises a first and second cutter provided on opposing sides of the gripping unit.

[0094] Clause ©. The harvesting tool of clause 5, wherein the gripping unit comprises a first drive, wherein the gripping unit and first drive are arranged to move the gripped petiole relative to the harvesting tool.

[0095] Clause 7. The harvesting tool of any of the previous clauses, further comprising a barrier extending away from the housing in a same direction as the gripping unit, the barrier being formed around the gripping unit as a protective cover thereof.

[0096] Clause 8. The harvesting tool of any of the previous clauses, further comprising a wrist between two housing parts, one part supporting the gripping unit, the other housing part having a mount for mounting on a robot arm.

[0097] Clause 9. Harvesting robot comprising a robot arm with a harvesting tool according to any of the previous claims attached to the robot arm.

[0098] Clause 10. A method of harvesting crops attached to a petiole of a plant using a harvesting tool with a robot arm, the method comprising the steps of: - positioning the harvesting tool; - locking the petiole with the harvesting tool; - moving the locked petiole relative to the harvesting tool; and - cutting the locked petiole.

[0099] Clause 11. The method of clause 10, wherein locking-on the petiole includes gripping, wherein moving the gripped petiole relative to the harvesting tool comprises re- positioning the harvesting tool in a direction towards a node where the petiole is attached to the plant.

[00100] Clause 12. The methods of clause 10 or 11, further comprising moving the harvesting tool along the locked, preferably gripped, petiole in a direction towards a node where the petiole is attached to the crop.

[00101] Clause 13. The method of any of the clauses 10-12, further comprising the step of re-positioning the harvesting tool with locked, preferably gripped, petiole to or above a container for storing crops.

[00102] Clause 14. The method of any clauses 10-13, wherein cutting comprises: - cutting the petiole between the locked, preferably gripped, location of the petiole and a node where the petiole is attached to the plant; and - cutting the petiole between the locked, preferably gripped, location of the petiole and a node where the petiole is attached to the crop.

Claims (14)

CONCLUSIONS L Harvesting device for harvesting crops connected to a stem of a plant, preferably the harvesting device being mountable on a robot arm, the harvesting device comprising: - a gripping unit for enclosing, preferably engaging, the stem therein; and - a cutting unit for cutting the stem, which is enclosed, preferably engaged, by the gripping unit, the gripping unit being adapted to move the enclosed, preferably engaged, stem relative to the harvesting device. 2. The harvesting device of claim 1, wherein the gripping unit comprises a first and a second roller, the stem being trapped between the rollers, preferably engaged, and the harvesting device has a drive for driving at least one of the rollers to move the trapped, preferably engaged, stem relative to the harvesting device. 3. The harvesting device of claims 1 or 2, wherein the gripper unit comprises a first and second gripper which can move towards each other to grip a stem therebetween. 4. The harvesting device of claims 2 and 3, wherein the first and second rollers are used as first and second grippers. 5. The harvesting apparatus of any of claims 1 to 4, wherein the cutting unit comprises a first cutter configured to make a first cut in the stem located on a first side of the gripping unit and a second cutter configured to make a second cut in the stem located on a second, different side of the gripping unit, the cutting unit preferably comprising a first and second cutter located on opposite sides of the gripping unit. 6. The harvesting device of claim 5, wherein the gripping unit comprises a first drive, the gripping unit and the first drive being adapted to move the gripped stem relative to the harvesting device. 7. The harvesting device of any preceding claim, further comprising a barrier extending from the housing in the same direction as the gripping unit, the barrier being formed around the gripping unit such that the barrier forms a protective cover for the gripping unit. 8. The harvesting device of any preceding claim, further comprising a wrist between two housing parts, one housing part supporting the gripping unit and the other housing part having a mounting point for mounting on a robot arm. 9. A harvesting robot comprising a robotic arm with a harvesting device according to any of the preceding claims attached to the robotic arm. 10. Method for harvesting crops attached to a stem of a plant using a harvesting device with a robot arm, the method comprising: - positioning the harvesting device: - enclosing the stem with the harvesting device; - moving the enclosing stem relative to the harvesting device; and - cutting off the enclosing stem. 11. The method of claim 10, wherein confining the stem comprises engaging, wherein moving the engaged stem relative to the harvesting device comprises moving the harvesting device in a direction toward a node where the stem is connected to a remainder of the plant. 12. Method according to claim 10 or 11, further comprising moving the harvesting device along the enclosed, preferably gripped, stem in a direction of a node by which the stem is connected to a fruit. 13. Method of any of claims 10-12, further comprising moving the harvesting device with the enclosed, preferably gripped, stem in the direction of, in particular above, a container for receiving the fruits therein. 14. The method of any of claims 10 to 13, wherein the cutting comprises: - cutting the stem between the confined, preferably gripped, location of the stem and a node connecting the stem to the plant; and - cutting the stem between the confined, preferably gripped, location of the stem and a node connecting the stem to the fruit.