AUTONOMOUS AGRICULTURAL ROBOT FOR CUTTING HOCK SHOOTS AND METHOD FOR DOING SO

Description

TECHNICAL FIELD

[0001] The present invention belongs to the field of industrial equipment used in agriculture, and relates more particularly to an autonomous robot for cutting suckers.

[0002] The present invention finds a direct application in the cultivation of shrubs of the Betulaceae family, and more particularly of hazel trees, by limiting the development of suckers and thus improving the yield of said hazel trees and the harvesting of hazelnuts. STATE OF THE ART

[0003] The cultivation of nuts, hazelnuts among others, saw significant development at the beginning of the 20th century, notably thanks to improvements in cultivation and harvesting techniques.

[0004] The main hazelnut production areas are in Europe (Italy, Turkey, France, Spain), North America (United States, Canada) and Asia (mainly China).

[0005] Hazelnuts are also grown in other parts of the world, such as Australia, North Africa and South America, but in smaller quantities.

[0006] During the 20th century, demand for hazelnuts continued to grow due to their popularity as an ingredient in many food products, as well as for their nutritional properties.

[0007] Thus, global production increased by almost 600% between the middle of the 20th century, reaching a quantity of 1,080,000 tonnes in 2021, according to the Food and Agriculture Organization of the United Nations.

[0008] This level of production was achieved by increasing the cultivated areas, but also the yield, by improving growing conditions, in particular by limiting the development of suckers.

[0009] Suckers are shoots that grow from the roots of hazelnut plants and can contaminate hazelnut orchards by developing outside the cultivated area. This can pose a problem for hazelnut cultivation because they can compete with cultivated plants for water and nutrients, leading to decreased yields and reduced hazelnut quality.

[0010] In addition, suckers can carry diseases (anthracnose, powdery mildew, etc.) and pests (hazelnut weevil, bugs, hazelnut ermine moth, etc.) which can spread to the hazelnut crop, resulting in significant losses for producers.

[0011] To combat suckers, there are several techniques such as manual weeding as well as mechanical weeding using specialized machines to pull up suckers, or the use of herbicide-type chemical products to eradicate suckers.

[0012] However, these techniques are generally inefficient or can have negative environmental impacts when chemicals are used. The development and use of autonomous robots in agriculture appears to be a solution that could address the challenges and constraints of hazelnut production while limiting the environmental impact.

[0013] As an example, document FR3001102A1 presents a self-contained agricultural device comprising, among other things, a power supply system and means of movement. The invention also includes a system for optimizing these movements.

[0014] This invention makes it possible to cultivate agricultural plots, maintain them, and collect data.

[0015] Document FR2994057A1 presents a vine pruning robot which mainly comprises a mobile structure on tracks which moves between rows of vines, a system for capturing images of the vines and their branches, and cutting pliers.

[0016] The images acquired are first processed by an onboard computer, which then provides instructions for pruning the vines. A camera system and its associated process are also presented. This system allows, among other things, the identification of branches that need to be cut.

[0017] However, these devices do not seem suitable for maintaining plots of crops with suckers that need pruning.

[0018] Furthermore, sucker removal systems exist but are not autonomous, requiring the presence and various actions of operators to control the proliferation of these suckers. These systems can therefore only be used a certain number of times a year, given the costs involved, on average five to six times depending on the orchard and the availability of operators for this task.

[0019] Documents EP 4 016 112 A2, FR 2 617 366 A1, US 2021 / 092911 A1, EP 3 574 744 A1 and FR 3 053 870 A1 illustrate alternative solutions.

[0020] It is therefore important to implement a sucker control strategy adapted to the characteristics of the hazelnut plot and allowing to minimize the risks of contamination while maintaining a high quality production that meets the growing demand.

[0021] The new solutions, based on the use of autonomous agricultural robots, must also adapt to all types of trees and terrain. Indeed, while the land is generally flat, it can also have irregularities that could limit the robots' movement, ultimately preventing them from operating with complete autonomy. PRESENTATION OF THE INVENTION

[0022] The present invention proposes an alternative to existing solutions, with an autonomous agricultural robot that eliminates the need for chemical inputs in the fight against suckers and improves, for example, the working conditions of hazelnut producers, without degrading farm yields, on the contrary.

[0023] For this purpose, the present invention relates to an autonomous agricultural robot for the maintenance of an orchard according to claim 1.

[0024] Depending on a particular characteristic, the robot includes at least one solar panel on all or part of its chassis.

[0025] According to another distinctive feature, the robot includes at least one LIDAR and / or high-resolution camera mounted on its chassis.

[0026] Advantageously, the cutting head comprises at least one interchangeable tree trunk protection ring which is fixed to said head by means of a plurality of screws on an upper peripheral surface Ps and / or a lower peripheral surface Pi of said head.

[0027] Advantageously, the protective crown has a multitude of fingers. Depending on a particular characteristic, the fingers are almost circular and / or oblong in shape, and are mainly defined individually by a diameter and a center.

[0028] According to another particular characteristic, two consecutive fingers are spaced on the protective crown by an inter-center space between each center characterizing said fingers.

[0029] Advantageously, the cutting head is suitable for cutting tree suckers in the orchard.

[0030] Advantageously, the cutting head is suitable for managing weeds in orchard rows.

[0031] Finally, the present invention also relates to a method for cutting suckers according to claim 10.

[0032] Advantageously, the process also includes a step of repositioning the robot.

[0033] Advantageously, the process also includes a step of moving the robot to another row of trees.

[0034] According to a particular feature, the process also includes a step of sending a notification of completion of work.

[0035] The fundamental concepts of the invention having been set forth above in their most elementary form, other details and characteristics will become clearer upon reading the description that follows and in view of the attached drawings. BRIEF DESCRIPTION OF THE FIGURES

[0036] The figures are provided for illustrative purposes only to aid understanding of the invention without limiting its scope. The various elements may be represented schematically and are not necessarily to the same scale. Throughout the figures, identical or equivalent elements are identified by the same numerical reference.

[0037] This is illustrated as follows: Figure 1 : a front perspective view of an autonomous agricultural robot for cutting suckers according to the preferred embodiment of the invention; Figure 2 : a side perspective view of the part of the robot containing a cutting tool; Figure 3A: a front perspective view of a robot arm incorporating a cutting system; Figure 3B : another front perspective view of the robot arm, when the cutting system has a negative inclination; Figure 3C : another front perspective view of the robot arm, when the cutting system has a positive inclination; Figure 4 : a top-down perspective view of the arm in a retracted configuration; Figure 5A : a perspective top view of a protective crown, according to a first embodiment; Figure 5B : a perspective top view of a protective crown, according to a second embodiment; Figure 6 : the main steps in a sucker cutting process; Figure 7 : a representation of the use of the autonomous agricultural robot in an orchard. DETAILED DESCRIPTION OF IMPLEMENTATION METHODS

[0038] It should be noted that certain technical elements well known to those skilled in the art are described here to avoid any insufficiency or ambiguity in the understanding of the present invention.

[0039] The embodiment described below refers to an autonomous agricultural robot, powered by solar panels, whose main functions, without limiting the invention, are to cut and control hazelnut shoots, thereby improving mechanized hazelnut harvesting, and also to maintain the ground cover in hazelnut orchards. Furthermore, this robot can operate continuously using batteries. This robot is also lightweight and adaptable to all types of terrain.

[0040] There figure 1represents an autonomous agricultural robot 100, according to a preferred embodiment of the invention, which mainly comprises a chassis 10, preferably made of aluminum, supporting wheels 11, an articulated arm 12, and a platform 16 located above said chassis.

[0041] Each of the 11 wheels is fitted with an all-terrain tire, allowing the 100 robot to move easily across different orchard terrains. Furthermore, to ensure sufficient stability on various surfaces, the 100 robot has a wheelbase of approximately 2 meters.

[0042] The articulated arm 12 is connected to the robot 100 by a pivot axis and is moved by means of an electric motor 124. This motor allows the arm to be deployed from a position on one side 100D of the robot 100, preferably located on the right side of the robot 100, to a desired position in a horizontal plane H at an angle R defined between the side 100D of the robot and a long edge 1231 of the part 123, up to a position that may be substantially perpendicular to said side. In other embodiments, the articulated arm 12 is fixed to a side 100G, located on the left side of the robot 100, and the positioning of said arm is then carried out relative to side 100G. In addition to deploying the articulated arm 12, the electric motor 124 also serves to move said arm by performing small-amplitude, back-and-forth rotations.

[0043] In the implementation mode represented at the figure 1The articulated arm 12 comprises three parts 121, 122, and 123, without this limiting the invention. Advantageously, the three parts 121, 122, and 123 slide relative to each other to allow, in particular, compact storage of the articulated arm 12. The deployment and retraction of the three parts 121, 122, and 123 is preferably performed manually, without this limiting the invention. Furthermore, parts 121 and 122 respectively comprise a stop 1211 and a stop 1222, as shown in the figure. figure 3A which halt the deployment of said parts.

[0044] The various parts 121, 122, and 123 of the articulated arm 12 are preferably screwed together. This feature does not limit the invention, as those skilled in the art could find other solutions for holding the various parts 121, 122, and 123 together when the articulated arm 12 is extended.

[0045] The extreme part 121 of the articulated arm 12 includes at least one interchangeable cutting head 13, for cutting suckers, comprising a cutting blade 134 rotated by means of an electric motor 131, said head also comprising a limit switch 133.

[0046] The cutting head 13 is fixed to part 121 of the articulated arm 12 by means of a horizontal axis 137, as shown in the figure 3A .

[0047] The attachment of the cutting head 13 allows a forward tilt of said head, with a travel of approximately 10 mm.

[0048] This angle is necessary to cut the suckers as close to the ground as possible. Thus, the limit switch 133 detects the contact of the cutting head 13, on which it is installed, with the trunk of a tree, and then commands a retraction of said head so that the cutting blade 134 does not damage said trunk.

[0049] In another embodiment, the articulated arm 12 is equipped with other types of tools, such as a cutting head dedicated to managing weeds in orchards or a cutting device adapted to lignified shoots such as an electric pruner.

[0050] Furthermore, and in the embodiment presented to the figure 1 The robot 100 includes a multitude of sensors, such as a front camera 17, a side camera 18, a rear camera 19, a distance sensor 14, a geolocation sensor 20, as well as a wireless communication system 15 allowing the exchange of a data stream remotely with an operator using a technology known to the person in the trade (Bluetooth, 2G / 3G / 4G / 5G, LoRa, ZigBee, Z-Wave, etc.), selected to best adapt to certain characteristics of the orchard (area, type of network available, etc.).

[0051] The front camera 17 and the rear camera 19 will primarily be used to align the robot 100 within the orchard and position it optimally in relation to the trees. The side camera 18 will detect the presence of suckers by analyzing the recorded images and thus instruct the robot 100 to cut them. Furthermore, the side camera 18 can detect if a branch is caught near the cutting heads 13, allowing the robot 100 to move its articulated arm 12 to free them. This functionality, among other things, guarantees the robot 100's complete autonomy without requiring human intervention during its work phases.

[0052] In some embodiments, the robot 100 is equipped with at least one lidar (English acronym for light detection and ranging, which can be translated into French by detection and estimation of distance by light) and / or at least one high-resolution camera in order to, for example, measure the size of tree trunks in an orchard, count the fruits present on a tree, and thus carry out orchard monitoring (identification of each tree).

[0053] In other embodiments, the robot 100 is suitable for use in the purpose of studying the soil of an orchard, in particular by mapping the soils by carrying out water measurements using at least one conductivity meter for example, or by taking soil samples for analysis, using for example an electric sampling auger.

[0054] In other embodiments, the robot 100 incorporates an odor detector and analyzer to locate truffles in the orchard that develop in symbiosis with hazelnut trees, for example.

[0055] Furthermore, in order to ensure monitoring of the different production sites, all the data collected is recorded in a database and then analyzed.

[0056] The robot 100 operates on electrical power, and its various components are powered by batteries 22, which are recharged by means of at least one solar panel 16 comprising a multitude of photovoltaic cells 161. This solar panel is sized to provide the electrical energy necessary for the proper functioning of the robot. The batteries 22 of the robot 100 can also be recharged by connecting the robot to an electricity distribution network in addition to the electrical energy supplied by the solar panel 16.

[0057] Preferably, the batteries 22 have two voltages. A first voltage of 12 V for part of the batteries 22 to power in particular the sensors, and a second voltage of 24 V for the other part of battery 22 used to power the motors of the wheels 11, the articulated arm 12, a steering of the robot 100 as well as the cutting heads 13.

[0058] In other embodiments, the voltage of some 22 batteries is 48 V in order to increase the power supply of the equipment connected to them.

[0059] Advantageously, the robot 100 is light enough not to crush hazelnuts on the ground or damage the soil when it is waterlogged, for example, after heavy rain. The robot preferably has a mass M of around 150 kg, although this is not a limitation of the present invention. Indeed, the choice of different materials by a person skilled in the art for the chassis 10, as well as the number of batteries 22, will influence the mass M.

[0060] The Robot 100 can then work right up until the hazelnut harvest, as the nuts are not damaged during the robot's passes. This technical feature of the Robot 100 is an advantage for growers, as it allows them to maintain their orchards year-round, regardless of harvest times or weather conditions.

[0061] In addition, the robot 100 is capable of operating at night, provided it is equipped beforehand with a suitable lighting system.

[0062] Thus, the regularity of the sucker cutting carried out by the robot 100 allows for optimal maintenance of the orchards.

[0063] Advantageously, images from the front camera 17, side camera 18 and rear camera 19 are also used to detect the presence of operators who may be near the robot 100, in order to avoid any risk of injury between said robot and the operators.

[0064] Finally, the robot 100 includes a control unit 25, such as an embedded computer, a PLC, or any other similar equipment known to those skilled in the art, enabling the piloting, control and automation of the movement, measurement and analysis functions implemented in said robot.

[0065] Preferably, the control unit 25 controls the charging of the batteries 22 as well as the monitoring of the consumption of the robot 100.

[0066] Similarly, preferably, all or part of the sensors and actuators of the robot 100 are connected to the control unit 25.

[0067] There figure 2 represents a perspective view of the part of the robot 100 on which the articulated arm 12 is installed.

[0068] A stepper motor 211 is installed on the chassis 10 of the robot 100 to adjust the height of the articulated arm 12 relative to the ground, by means of a vertical linear mechanism 21 which includes a belt (not shown here) that adjusts the height of a platform 212 on which the motor 124 is fixed, as shown in the figure 1 The vertical linear unit is capable of supporting a load of 35 kg.

[0069] In the embodiment described here, the robot 100 comprises a single vertical linear 21.

[0070] In other embodiments, the robot 100 includes two vertical linears in order to support a larger load at the level of the articulated arm 12, said linears being driven by the same stepper motor 211.

[0071] Indeed, since the orchard has uneven soil, height differences of around ten centimeters must be compensated for in order to cut the suckers as close to the ground as possible. Without the 211 stepper motor, a "flower cut" cannot be performed.

[0072] There figure 3A , there figure 3B and the figure 3C represent perspective views of the articulated arm 12 of the robot 100, said arm being equipped with two cutting heads 13.

[0073] There figure 3A represents the articulated arm 12 and the two cutting heads 13 when said arm is in the sucker cutting position.

[0074] Thus, the blade 134 is protected from potential damage from the ground by means of a protective plate 135, located in the lower part of the cutting head 13. Furthermore, to protect the tree trunks, the cutting head 13 has, on an upper peripheral surface Ps and / or a lower peripheral surface Pi, A tree trunk protection ring 132 has multiple fingers 1321 that keep the trunk at a distance from the blade 134, while still allowing the cutting of suckers. The fingers 1321 protect the tree in place but are sized to allow suckers to enter the cutting heads 13 so they can be cut by the cutting blade 134. The protection ring 132 is screwed onto the cutting head 13 by means of a plurality of screws 1325, as shown in the figure. figure 1 .

[0075] When the cutting head 13 is positioned in front of the base of a hazel tree and its suckers, said head is slightly inclined forwards while rotating around the axis 137.

[0076] Furthermore, since part 121 is freely articulated relative to part 122, part 121 can pivot in the plane V vertical to the front face 1221 of part 122, as shown in the figure 1 , then inclined relative to part 122. This inclination allows the suckers to be cut as close as possible to the ground, facilitating in particular the maintenance of the orchards, the suckers once cut not protruding from the ground, or of a negligible height.

[0077] The state of the inclination of part 121, positive, negative or zero, relative to plane 122 in plane V is measured by means of two push-button limit switches 126, installed on either side of a support 125 which is positioned on part 122. Each limit switch 126 includes a push button 1261 which is located above part 121. Thus, depending on the state of the push buttons 1261 (open or closed), it is possible to deduce how part 121 is inclined relative to part 122.

[0078] THE Figures 3B and 3C represent the articulated arm 12 for different inclinations of the part 121 comprising the two cutting heads 13, with respect to a horizontal axis X, representing a zero inclination

[0079] Thus on the figure 3B ,When the inclination is at an angle α, this information, measured by the limit switches 126, is interpreted by the control unit 25 of the robot 100 as the articulated arm 12 being positioned too high relative to the ground. Indeed, the part 121, due to its mass and the action of gravity, naturally tilts towards the ground and cannot be in contact with it. If the robot 100 is expected to cut suckers at this time, a command is sent to the motor 211 to lower the articulated arm 12.

[0080] Conversely, and on the figure 3C , When the inclination presents an angle b, this information is interpreted by the control unit 25 of the robot 100 as a position that is too low relative to the ground for the articulated arm 12. In this case, a command is sent to the motor 211 to raise the articulated arm 12 so that part 121 of said arm is in a position close to that shown in the figure 3A(that is, with zero inclination in plane V).

[0081] There figure 4 represents the articulated arm 12 when each of the parts 121, 122 and 123 that comprise said arm are retracted by sliding them into one another. Advantageously, the volume thus occupied by the articulated arm 12 is minimized and allows for easier storage and transport than when said arm is extended.

[0082] There figure 5A and the figure 5B represent respectively a protective crown 132 and a protective crown 232, according to a first and a second embodiment, when these are not screwed onto the cutting head 13. Advantageously, the protective crowns 132 and 232 are interchangeable in order to adapt to the orchards in which the robot 100 performs maintenance work.

[0083] Indeed, depending on the season and the size of the suckers and tree trunks, it may be necessary to change the protective crowns 132 and 232 to ensure optimal cutting while preserving the tree trunks. The protective crowns 132 and 232 are easily changed, as they have numerous holes 1324 and 2324, some threaded and some not, allowing them to be screwed onto and unscrewed from the cutting heads 13.

[0084] The protective crowns 132 and 232 are characterized among other things by a number N132 of fingers 1321 and a number N232 of fingers 2321. Preferably, the fingers 1321 have an external shape almost circular and the fingers 2321 have an external shape oblong, without this representing a limitation to the invention, other shapes being able to be used by the person skilled in the art, such as triangular, rectangular.

[0085] In the embodiment shown in the figure 5AThe shape of each finger 1321 is defined by a diameter d1321 and a center 1322. The fingers 1321 are distributed, uniformly or unevenly, around the periphery of the protective ring 132, said fingers being spaced by an intercenter distance E1321. The intercenter distance E1321, the diameter d1321, and an external edge b132 of the protective ring 132 then define an interfinger zone Z232, which is hatched on the figure 5A .

[0086] In the embodiment shown in the figure 5BThe oblong shape of each finger 2321 is defined by a semicircular end of diameter d2321, a width e2321 equal to the diameter d2321, and a depth p2321 average between an outer edge b232 of the protective crown 232 and an end x2321 of said finger, and finally a center 2322. As before, the fingers 2321 are distributed, uniformly or not, around the periphery of the protective crown 232, said fingers being spaced by an intercenter space E2321. Between two consecutive fingers 2321 and the outer edge b232 of the protective crown 232, an interfinger zone Z232 is defined, which is hatched on the figure 5B .

[0087] Advantageously, the inter-finger zones Z132 and Z232 are the spaces into which suckers insert during pruning operations, allowing the blades 134 to cut said suckers. Conversely, the fingers 1321 and 2321 keep the tree trunk away from the blades 134 so that the trunks are not damaged by said blades.

[0088] There figure 6 represents the main steps of a 500 sucker cutting process in an orchard 600, as shown in the figure 7 , using the autonomous agricultural robot 100, for a particular implementation method.

[0089] Process 500 mainly comprises: a step 510 of verifying the registration of the orchard 600 in mapping software to authorize the start of the robot 100; a step 520 of aligning the robot 100 with respect to a row of trees 61-63, as shown in the figure 7; a step 530 of measuring the distance between the robot 100 and a tree 611a-c, 621a-b of the orchard 600; a step of positioning the articulated arm 12 at the level of the tree if the position of the robot 100 is correct and a step 542 of repositioning the robot 100 relative to the tree if the position of the robot 100 is not correct; a step 550 of cutting the suckers using the cutting heads 13 of the robot 100; a step 560 of moving the robot to the next tree, if the row of trees 61-62 in which the robot is located still contains some; a step 570 of moving the robot to another row of trees 61-62, if there are still rows to work in the orchard 600; and a step 580 of sending a notification of completion of work to an operator.

[0090] Step 510 aims to ensure that the orchard 600 in which the robot 100 is located has been previously entered into the mapping software included in the robot's control unit 25. The robot 100 will then compare its position, obtained using its geolocation sensor 20, with the georeferenced work zones. If the robot 100's position is within a work zone, it will be authorized to move and activate the cutting heads 13. Thus, the robot 100 can only operate autonomously within a predetermined zone.

[0091] This is a necessary safeguard to avoid, in particular, any risk of degradation in areas of non-selected cultivation.

[0092] Furthermore, this check will allow the robot 100 to be contained within a specific area, even if that area lacks a physical boundary. Indeed, the orchard 600 may not be delimited by fences or barriers, for example, which would physically prevent the robot 100 from moving to another location. Once the start command is given, the robot 100 is then authorized to begin the work of pruning the suckers.

[0093] Step 520, the alignment of robot 100 in the orchard 600, and in relation to a row of trees 61-62, will consist of positioning robot 100 so that said row, where sucker pruning work is planned, is on the side where the articulated arm 12 is installed. Step 520 is carried out using images collected by the front camera 17 and rear camera 19 of robot 100. The tree 611a-c, 621a-b on which robot 100 will perform maintenance is then detected and selected using the side camera 18. In some embodiments, and when each tree 611a-c, 621a-b has been entered into the robot's mapping software, it is possible to select only certain trees 611a-c, 621a-b to perform the work. This selection makes it possible in particular to optimize the time spent by robot 100 in orchard 600 by not lingering on trees 611a-c, 621a-b which do not require maintenance.

[0094] Step 530 of measuring the distance between robot 100 and tree 611a-c, 621a-b, of orchard 600 is then carried out using distance sensor 14.

[0095] If the position of the robot 100, and its distance from the tree 611a-c, 621a-b, is correct, the robot will then rotate the articulated arm 12 by means of a rotational movement performed by the electric motor 124 during step 541 of positioning said arm. In addition, the height of the articulated arm 12 relative to the orchard floor 600 is adjusted by means of the motor 211 so that the cutting heads 13 are as close as possible to the base of the suckers 6111a, as shown in the diagram. figure 7 .

[0096] In the opposite case where the position of the robot 100, as well as its distance from the shaft 611a-c, 621a-b are not correct, said robot moves during the automatic repositioning step 542 in order to then be able to deploy the articulated arm 12.

[0097] Step 550, which involves cutting the suckers using the cutting heads 13 of robot 100, is then carried out. Prior to and during step 550, an analysis of the number of suckers to be cut is performed on trees 611a-c and 621a-b, so that robot 100 can adjust its speed, which is generally around 1.5 km / h. Therefore, robot 100 is not dependent on the vegetative development of orchard 600 and can be used without prior preparation of the orchard, for example, if a large number of suckers need to be cut. Furthermore, if there are no suckers to cut, the robot does not approach trees 611a-c and 621a-b and moves on to the next tree. Similarly, and before moving on to the next tree, a check is carried out by the side camera 18 to ensure that all the suckers 6111a have been cut flush.Indeed, to properly maintain the orchard, the suckers must be cut as close to the ground as possible to prevent them from becoming trapped, particularly in areas where hazelnuts could become trapped. To achieve this, the cutting heads are positioned close to the suckers and wrap around the base of the tree to cut them.

[0098] In addition, the motor 124 makes rotations of small amplitudes which result in back and forth movements of the articulated arm 12 and make it easier to cut the suckers 6111a.

[0099] When the suckers 6111a are cut, the cutting heads 13 exert pressure at the base of the tree, which is transmitted to the articulated arm 12, causing the arm to retract by means of the motor 124. Thus, the power of the motor 124 is adjusted according to two parameters: the density of suckers 6111a to be cut, which is evaluated by means of the camera 18; the amount of inclinations of the cutting heads 13 caused by contact with the suckers and which also indicates a number of suckers 6111a that have been cut.

[0100] In addition, the control unit 25 continuously measures an electrical current Imoteur which independently cycles through each of the motors 131 that rotate their blade 134. This continuous measurement of the electrical current Imotor allows for the evaluation of the mechanical stresses at each of the blades 134. Indeed, the higher the electrical current Imotor, the greater the mechanical stresses at the blades 134. Depending on certain thresholds and the observed durations of exceeding these thresholds, actions are defined, such as shutting down the robot 100 for safety, or sending notifications to an operator.

[0101] During step 560 of moving the robot 100 towards the next tree, the articulated arm 12 is raised if necessary to facilitate the movement of said robot, and in particular to prevent the mower heads 13 from being damaged by coming into contact with the ground.

[0102] Once the sucker pruning 6111a has been completed in a row of trees 61-63, step 570, which involves moving robot 100 to another row, is carried out if the row being maintained is not the last. Robot 100 will then make a U-turn at the end of the row and realign itself with the trees of a row, continuing the pruning until all the tree bases have been maintained.

[0103] When maintenance work in the orchard has been completed, a notification is sent to at least one operator to inform them. This notification can be sent, for example, via SMS (an acronym for SMS). Short Message Service), or by any other means of communication known to a person skilled in the art, and depending on the possibilities of sending information remotely in the geographical area where robot 100 is located.

[0104] There figure 7 represents an example of the use of robot 100 in orchard 600 to cut suckers 6111a.

[0105] Thanks to the use of robot 100 in orchard 600, the use of contact herbicides to control suckers 6111a and the use of systemic herbicides to control weeds on rows 61-62 are reduced.

[0106] Furthermore, due to its autonomous operation, the robot 100 is capable of maintaining the orchard 600 at a higher frequency than existing solutions that require the continuous presence of at least one operator. Thus, a minimum of one monthly visit by the robot 100 to the orchard 600 is possible, whereas existing solutions, primarily for cost and time reasons, are limited to an average of four visits per year.

[0107] Finally, the autonomous agricultural robot 100 is suitable, subject in particular to adaptations to its dimensions which can be carried out by a person in the trade, for use in orchards 600 where other types of trees are cultivated and producing for example nuts (walnuts, chestnuts, almonds, etc.), stone fruits (plums, apricots, cherries, etc.) or pome fruits (apples, pears, lemons, etc.).

Claims

1. Autonomous agricultural robot (100) for maintaining an orchard (600) wherein trees (611a-c, 621a-b) are cultivated, said robot comprising a chassis (10), supported by four wheels (11) suitable for moving on any type of terrain, and defining a wheelbase E100, of the order of 2 m between the front wheels (11), said chassis integrating a front camera (17), a side camera (18), a rear camera (19), a communication system (15), a geolocation sensor (20), a control unit (25) as well as at least one battery (22), characterised in that said robot comprises at least one articulated arm (12), comprising at least two parts (121, 122, 123) sliding in one another, said arm performing rotations of an angle R in a horizontal plane H by means of an electric motor (124), said arm comprising at least one interchangeable cutting head (13), as well as a distance sensor (14) for measuring a distance between said robot and said trees; said robot wherein the articulated arm (12) is positioned vertically by means of a vertical linear element (21) attached to the chassis (10), and comprising a platform (212) driven by means of a stepper motor (211); the part (121) of the articulated arm (12) on which the cutting head (13) is attached being inclined at an angle a or b, in a vertical plane V of a front face (1221) of said arm.

2. Robot (100) according to one of the preceding claims, and comprising at least one solar panel (16) on all or part of the chassis (10) of said robot.

3. Robot (100) according to any one of the preceding claims, and comprising at least one LIDAR and / or a high-resolution camera attached to the chassis (10) of said robot.

4. Robot (100) according to any one of the preceding claims, and wherein the cutting head (13) comprises at least one interchangeable tree trunk protection ring (132, 232) which is attached to said head by means of a plurality of screws (1325) on an upper peripheral surface Ps and / or a lower peripheral surface Pi of said head.

5. Robot (100) according to Claim 4, and wherein the protection ring (132, 232) comprises a plurality of fingers (1321, 2321).

6. Robot (100) according to Claim 5, and wherein the fingers (1321, 2321) have a near-circular shape and / or an oblong shape, and are defined individually by a diameter (d1321) and a centre (1322).

7. Robot (100) according to Claim 6, and wherein two consecutive fingers (1321, 2321) are spaced apart on the protection ring (132, 232) by an inter-centre space (E1321, E2321) between each centre (1322, 2322) characterising said fingers.

8. Robot (100) according to any one of the preceding claims, and wherein the cutting head (13) is capable of cutting suckers (6111a) from trees (611a) in the orchard (600).

9. Robot (100) according to any one of the preceding claims, and wherein the cutting head (13) is capable of managing the vegetation cover in rows (61-62) of orchards (600).

10. Method (500) for cutting suckers (6111a) by means of at least one cutting head (13), said method being implemented by a robot (100) according to one of Claims 1 to 9, and characterised in that it comprises the following steps: - (510) of verifying that the orchard (600) is registered in mapping software of the control unit (25) in order to authorise the robot (100) to start up; - (520) of aligning the robot (100) with respect to a row of trees (61-62) by means of the front (17) and rear (19) cameras of said robot; - (530) of measuring the distance between the robot (100) and a tree (611a-c, 621a-b) in the orchard (600); - (541) of positioning the articulated arm (12) of the robot (100) by means of the electric motor (124) as well as the stepper motor (211); - (550) of cutting the suckers by means of the cutting heads (13) of the robot (100); and - (560) of moving the robot to a next tree;11. Method (500) according to Claim 10, further comprising a step (542) of repositioning the robot (100).

12. Method (500) according to Claim 10 or 11, further comprising a step (570) of moving the robot to another row of trees (61-62).

13. Method (500) according to any one of Claims 10 to 12, further comprising a step (580) of sending a notification that the work is complete.