Agricultural robot with a tool carrier lifting device configurable for any type of crop

Abstract

The invention relates to an agricultural robot comprising a straddle-type chassis, equipped with a plurality of rows of rolling elements parallel to a main axis of movement and allowing the agricultural robot to move on ground, the chassis having at the center a ground clearance greater than a predetermined height. The agricultural robot also comprises a tool holder having at least one arm carrying at least one tool, the arm pivoting about an axis while being connected by a cable to a winch fixed to the chassis, the height of the tool relative to the chassis being adjusted by said winch, the arm being configured to be fully raised above the ground clearance in a so-called high position. Figure for abstract: figure 1

Description

Title of the invention: Agricultural robot comprising a device for lifting a tool holder configurable for any type of crop TECHNICAL FIELD OF THE INVENTION

[0001] The field of the invention is that of agricultural machinery.

[0002] More specifically, the invention relates to an agricultural robot comprising a device for lifting a tool holder configurable for any type of crop.

[0003] The invention finds applications in particular for the preparation and maintenance of a crop field, particularly for large-scale crops such as the cultivation of cereals (wheat, barley, corn, etc.), the cultivation of oilseeds (sunflower, rapeseed, soybeans, etc.) or that of protein crops (peas, field beans, etc.). STATE OF THE ART

[0004] Agricultural robot techniques are known from the prior art, having tool holders particularly adapted to carry out an action close to the ground, or even in contact with the ground. This may be, for example, a hoeing or weeding action.

[0005] Tool holders generally comprise arms actuated by jacks enabling the arm to be positioned relative to the ground in order to enable the action of a tool carried by the arm.

[0006] These jacks generally provide mechanical rigidity which can be useful for holding the tool in position but does not allow natural freedom in the working position allowing it to actually follow the terrain.

[0007] However, the jacks have limited travel, requiring complex assemblies if one seeks to increase the travel.

[0008] Furthermore, the mechanical complexity will also increase when it is sought to make several tools of a tool holder independent of each other.

[0009] It should be emphasized that an agricultural robot generally seeks to treat several rows of crops simultaneously and that each of these rows has height disparities specific to a crop field.

[0010] The mechanical complexity becoming significant to independently manage the tools of the tool holder implies that the tool holders are generally not configured to be lifted above fifty centimeters from the ground. In the case of a field of large crops, exceeding this height, the agricultural robots of the prior art are generally not implemented because they damage the crops present while there is still a need to act against weeds growing in the field.

[0011] There are tool carrier techniques that allow them to be lifted higher, especially when the tool carriers are associated with a tractor and generally articulated externally of the tractor chassis. On the one hand, these techniques are not compatible with an agricultural robot that has less mechanical power. On the other hand, positioning outside the chassis is incompatible with an agricultural robot that has safety systems allowing it to move alone in the environment.

[0012] None of the current systems can simultaneously meet all the required needs, namely to offer an agricultural robot technique which has a tool holder adapted to any type of crop and in particular to a large-scale crop field, i.e. having significant ground clearance. Statement of the invention

[0013] The present invention aims to remedy all or part of the drawbacks of the state of the art cited above.

[0014] To this end, the invention relates to an agricultural robot comprising a straddle-type chassis, equipped with a plurality of rows of rolling elements parallel to a main axis of movement and allowing the agricultural robot to move on the ground, the chassis having in the center a ground clearance greater than a predetermined height, characterized in that the agricultural robot also comprises a tool holder having at least one arm carrying at least one tool, the arm pivoting about an axis while being connected by a cable to a winch fixed to the chassis, the height of the tool relative to the chassis being adjusted by said winch, the arm being configured to be fully raised above the ground clearance in a so-called high position.

[0015] Thus, at least one tool can be raised into the high position making it possible to secure this or these tool(s) during a movement of the agricultural robot which can then step over an obstacle or part of the crop, in particular during a phase of repositioning the agricultural robot.

[0016] In addition, the use of the winch allows lifting of the tool(s) with a significant movement that is easily controlled at height. Several height configurations are thus possible: • low working position with the tool(s) at least close to the ground; • intermediate position; • high position for storage and safety.

[0017] By extension, here we mean by rope any type of element capable of being wound in the winch in order to lift the arm of the tool holder, such as a cable, a chain, a strap, etc.

[0018] In particular embodiments of the invention, the tool holder comprises a plurality of arms each carrying at least one tool, each arm pivoting around an axis and being connected by a cable to a separate winch fixed to the chassis, the arms being configured to be fully raised above the ground clearance in the high configuration.

[0019] It should be emphasized that for the sake of clarity of reading, each winch comprises only one drum on which a rope is wound. The case of a winch with several drums will be considered as equivalent to a plurality of winches with a single drum, each winch being able to be operated synchronously.

[0020] In particular embodiments of the invention, all the arms pivot around a common axis.

[0021] In particular embodiments of the invention, the agricultural robot comprises an actuator driving at least two winches at the same time.

[0022] The arms operated by the two winches can then be advantageously synchronized.

[0023] In particular embodiments of the invention, at least one rope rests on at least one separate pulley of the winch.

[0024] The use of a pulley, for example positioned directly above an arm carrying at least one tool, advantageously makes it possible to reduce the force required to lift said arm.

[0025] In particular embodiments of the invention, the ground clearance is greater than fifty centimeters.

[0026] In particular embodiments of the invention, at least one arm has a ground tracking device.

[0027] A ground tracking device may be of a mechanical type such as a wheel or of an electronic type such as for example a LIDAR.

[0028] In particular embodiments of the invention, the tool holder is presented by the lower face of the chassis, facing the ground.

[0029] In particular embodiments of the invention, the tool holder is configured to move exclusively within a space delimited by the chassis.

[0030] Thus, the tool holder is protected inside the chassis, thus providing additional safety for an individual moving around the robot.

[0031] In particular embodiments of the invention, the pivot axis of each arm is secured to a support of the chassis, the support being configured to translate relative to the chassis, perpendicular to the main axis of movement of the agricultural robot, the support being separate for each arm or common to at least two arms.

[0032] Thus each arm can be translated to the right or left relative to the main axis of movement of the robot, offering the possibility of adjusting the lateral position of the tool(s) relative to the actual position of the sowing. It should be emphasized that agricultural land is generally not perfectly flat, presenting reliefs capable of making the agricultural robot pitch or roll relative to the horizontal.

[0033] The support may be of the trapezoidal type.

[0034] Advantageously, the agricultural robot can comprise a device for controlling the parallelism of the arms.

[0035] In particular embodiments of the invention, the agricultural robot comprises a device for determining the position of a row of crops relative to the agricultural robot and a device for adjusting the position of an arm relative to said row of crops.

[0036] Thus, the agricultural robot can adapt to any type of terrain by adjusting in real time the position of an arm in height and / or laterally in relation to the sowing.

[0037] In particular embodiments of the invention, the agricultural robot comprises a device for monitoring the integrity of at least one cable. BRIEF DESCRIPTION OF THE FIGURES

[0038] Other advantages, aims and particular characteristics of the present invention will emerge from the following non-limiting description of at least one particular embodiment of the devices and methods which are the subject of the present invention, with reference to the appended drawings, in which: • [Fig.l] is a perspective view of an agricultural robot according to the invention moving in a crop field; • [Fig.2] is a side sectional view of the agricultural robot of [Fig.l]; • [Fig.3] is a side sectional view of the agricultural robot of [Fig.l] according to a other embodiment; • [Fig.4] is a top sectional view of the agricultural robot of [Fig.l]; • [Fig.5] is a sectional view from above of the agricultural robot of [Fig.l] according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous manner.

[0040] It should be noted, from now on, that the figures are not to scale. Example of a particular embodiment

[0041] [Fig.l] is a schematic view of an agricultural robot 100 moving in a crop field 105. The agricultural robot 100 comprises a straddle-type chassis 110, comprising a platform 111, substantially parallel to the crop field 105, connecting two rows 112 of rolling elements 115 in contact with the field 105. The agricultural robot 100 moves along a main axis 120, parallel to the two rows 112. The main axis 120 of movement of the agricultural robot 100 corresponds to the direction of the crop rows 140 of the field 105 when the agricultural robot 100 follows the rows 140 to treat them.

[0042] For this purpose, the agricultural robot 100 advantageously comprises a device 145 for acquiring a stream of data in real time, which may be images or data from a scanner such as a LIDAR (acronym for the English term “laser imaging detection and ranging”). The data acquired by the device 145 are processed by a device 146 for determining the position and orientation of at least one row 140 of crops relative to the chassis 110. The device 146, which comprises a logic unit, is here integrated inside the chassis 110, and allows the robot 100 to follow the rows 140 of crops.

[0043] The chassis 110 advantageously has a ground clearance 130 greater than a predetermined height, for example fifty centimeters, or even eighty centimeters, sufficient to span possible obstacles and the rows 140 of crops.

[0044] It should be emphasized that the agricultural robot 100 is configured to intervene in the crop field 105, in particular for maintenance operations, such as weeding weeds 150 present near the plantations 141.

[0045] To this end, the agricultural robot 100 has, in the present non-limiting example of the invention, a tool holder 160 preferably moving entirely within the perimeter of the chassis 110 for safety reasons.

[0046] The tool holder 160 comprises a plurality of arms 165, in this case three arms 165, each of the arms 165 carrying at least one tool 166 chosen according to the desired treatment.

[0047] Advantageously, as illustrated in [Fig.2] which is a sectional view of the agricultural robot 100 along an axis parallel to the main axis of movement 120, each arm 165 pivots around an axis 210 which is in the present non-limiting example of the invention common to all the arms 165. Each arm 165 can thus pivot between a first position, called storage, where the arm is substantially parallel to the platform 111, making it possible to raise the tools 166 above the ground clearance 130, and a second position, called treatment, where the tools 166 are in contact with the field 105 of cultivation. Of course, all intermediate positions between the storage position and the treatment position are possible.

[0048] The adjustment of the pivoting of each arm 165 is advantageously carried out according to the invention by means of a winch 220 which can be common to several arms 165 or separate for each arm 165. Each arm 165 is thus in the present non-limiting example of the invention connected to a separate winch 220 by means of a rope 225 which can be a cable, a chain or any other type of rope.

[0049] The integrity of a cable 225 can advantageously be checked by a control device 226 measuring for example the electrical resistivity of an electric wire running along the cable 225. The check can also be carried out by means of a measurement of the tension at the winch 220.

[0050] Advantageously, a pulley 230 is positioned directly above each arm 165 carrying tools 166, in order to reduce the force required to lift said arm 165. Preferably, the pulley 230 is positioned directly above the center of gravity of the arm 165 and of the tools 166 carried by the arm 165, or even directly above the center of gravity of the tools 166, only, carried by the arm 165. An intermediate position between these two points can also be envisaged.

[0051] It should be emphasized that, as illustrated in [Fig.3], a plurality of pulleys 230 can be used to multiply the forces on each winch 220.

[0052] Each arm 165 may also comprise a wheel 235 intended to roll on the field 105 in order to follow the ground and guide in height the tools 166 carried by the corresponding arm 165.

[0053] Each arm 165 can advantageously be secured to a support 240 of the chassis 110, configured to translate parallel to the chassis 110 and to the field 105, perpendicular to the main axis 120 of movement of the robot 100. The support 240 thus pivots along a substantially vertical axis 250 when the robot 100 moves in the field 105.

[0054] As illustrated in [Fig.4], which is a top view of the tool holder 160 comprising three arms 165, the support 240 of each arm 165 has a parallelepiped shape composed of a support bar 410 and two parallel arms 420 each pivoting around an axis 250.

[0055] The translation of each support 240 is for example carried out by means of a jack 430 or any other linear displacement device known to those skilled in the art.

[0056] The arms 165 are here adjusted in height by means of a single winch 220, the cables 225 being wound around a single bar 430.

[0057] In an alternative embodiment illustrated in [Fig. 5], each arm 165 is adjusted in height by a separate winch 220. The three winches 220 can be aligned or offset as in [Fig. 5]. It should be emphasized that the winches 220 can be actuated separately or at the same time by one or more independent actuators, each winch 220 being able to be associated with a separate actuator for greater flexibility in use.

[0058] By adjusting the height of an arm 165 and its lateral position relative to the chassis 110, the position of the tools 166 carried by the arm 165 can be advantageously adjusted relative to the position of the row 140 of crops being treated. The adjustment of the height and the lateral position is here carried out by an adjustment device 147 illustrated in [Fig.l]. The adjustment device 147 is for this purpose connected to the device 146 for determining the position of a row 140 of crops relative to the chassis 110. Other advantages and optional features

[0059] The ropes 225 may be straps offering a significant advantage over a cable, in particular insofar as the winding and unwinding of a strap is carried out without blocking whereas a cable may tend to get blocked in the winch by friction. The use of a strap thus allows for smooth and uninterrupted operation of the agricultural robot.

[0060] In addition, the necessary lifting torque provided by the winch can be reduced, for example halved, by using pulleys. This means that the winch can have reduced power, which can extend the life of the motor and reduce the energy consumption of the agricultural robot.

[0061] The pulley and strap system is also simple to control, allowing for precision in positioning tools at height. This can be particularly useful in agricultural applications where precision can be essential to avoid damaging crops.

[0062] In addition, the system is easy to set up. It does not require high precision in manufacturing, which can make manufacturing more economical. This can make the agricultural robot more affordable for farmers.

[0063] Finally, the position of the winch can be easily modified, for example moved towards the front or rear of the chassis 110 with respect to the main axis of movement 120. Thus, it is possible to maintain a reduced footprint, even by multiplying the number of actuators.

[0064] Furthermore, it should be emphasized that the winch motor can be advantageously controlled in position, by determining a zero position measurement, known by the English term “homing”, when the tools 166 are in the raised position, then by unwinding a measurable number of turns. The sensor measuring the zero position can be for example a position sensor or an encoder relative to the winch motor.

[0065] The agricultural robot 100 generally comprises an element for verifying the high position of the tool holder 160 or the winding of the winch 220. This element may be an inductive, capacitive, mechanical sensor or a rotary or linear absolute encoder. In addition, the agricultural robot 100 may also comprise an element for verifying the low position of the tool holder 160 or the unwinding of the winch 220, which may also be an inductive, capacitive, mechanical sensor or a rotary or linear absolute encoder.

[0066] It should be emphasized that the arms 165 of the tool holder 160 of the agricultural robot 100 are always parallel to the two rows 112 of wheels 115 of the robot 100, which is essential for carrying out work in the field 105.

[0067] The agricultural robot may also comprise an element for measuring the angular position of each arm 165 independently, which makes it possible to determine the height of the tools 166 carried by each arm 165 relative to the chassis 110.

[0068] In addition, the agricultural robot 100 may comprise an element for measuring the lateral position of each support bar 410, which makes it possible to determine the position of each arm 165 in width relative to the chassis 110, i.e. perpendicular to the main axis 120 of movement of the robot 100.

[0069] The agricultural robot 100 may also comprise an element for measuring the three-dimensional position of each arm 165 independently, which makes it possible to determine the height and width position of each arm 165 relative to the chassis 110. This measuring element may in particular be composed of a camera and a device for detecting known or even calibrated targets in an image acquired by the camera.

[0070] The agricultural robot 100 may also comprise a device for verifying the integrity of the ropes 165, such as straps or lifting cables. This verification may for example be carried out by monitoring the consumption of the motor during the raising and lowering of the tools 166. The integrity of the ropes may also be ensured by a device for measuring the resistivity of an electric cable integrated into a rope 165.

Claims

Claims

1. Agricultural robot (100) comprising a straddle-type chassis (110), equipped with a plurality of rows (112) of rolling elements (115) parallel to a main axis of movement (120) and allowing the agricultural robot to move on ground, the chassis having at the center a ground clearance (130) greater than a predetermined height, characterized in that the agricultural robot also comprises a tool holder (160) having at least one arm (165) carrying at least one tool (166), the arm pivoting about an axis (210) while being connected by a cable to a winch (220) fixed to the chassis, the height of the tool relative to the chassis being adjusted by said winch, the arm being configured to be fully raised above the ground clearance in a so-called high position.

2. An agricultural robot according to claim 1, wherein the tool carrier comprises a plurality of arms each carrying at least one tool, each arm pivoting about an axis and being connected by a cable to a separate winch fixed to the chassis, the arms being configured to be fully raised above the ground clearance in the high configuration.

3. An agricultural robot according to claim 2, wherein all arms pivot about a common axis.

4. An agricultural robot according to any one of claims 2 to 3, comprising an actuator driving at least two winches at the same time.

5. Agricultural robot according to any one of claims 1 to 3, in which at least one cable rests on at least one separate pulley of the winch.

6. An agricultural robot according to any one of claims 1 to 4, wherein the ground clearance is greater than fifty centimeters.

7. An agricultural robot according to any one of claims 1 to 5, wherein at least one arm has a ground tracking device.

8. Agricultural robot according to any one of claims 1 to 6, in which the tool holder is presented by the lower face of the chassis, facing the ground.

9. Agricultural robot according to any one of claims 1 to 7, wherein the tool holder is configured to move exclusively within a space delimited by the chassis.

10. Agricultural robot according to any one of claims 1 to 8, in which the pivot axis of each arm is secured to a support of the chassis, the support being configured to translate relative to the chassis, perpendicular to the main axis of movement of the agricultural robot, the support being separate for each arm or common to at least two arms.

11. Agricultural robot according to any one of claims 1 to 9, comprising a device for determining the position of a row of crops relative to the agricultural robot and a device for adjusting the position of an arm relative to said row of crops.

12. Agricultural robot according to any one of claims 1 to 10, comprising a device (226) for monitoring the integrity of at least one cable (225).

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