DEVICE, KIT AND METHOD FOR DETECTING ELEVATIONS AND / OR OBSTACLES IN A FIELD

Abstract

TITLE OF THE INVENTION: DEVICE, KIT AND METHOD FOR DETECTING ELEVATIONS AND / OR OBSTACLES IN A FIELD A device (100) for detecting elevation differences and / or obstacles in a field, which comprises:- a chassis comprising:- at least one tool (116, 136),- at least one means for detecting an obstacle (115, 135),- at least one means for detecting an elevation difference comprising a wheel (119) resting on the ground and a contact sensor (120) of the wheel on the ground,- a means for modifying (114, 134, 113, 133, 123, 143) the relative position of the wheel and / or the at least one tool with respect to the chassis,- a control means (150) configured to control the modification of the position of the wheel and / or the at least one tool :- when an obstacle is detected and / or- when a lack of contact between the wheel and the ground is detected. Figure for the abstract: figure 1

Description

Title of the invention: DEVICE, KIT AND METHOD FOR DETECTING ELEVATIONS AND / OR OBSTACLES IN A FIELD Technical field of the invention

[0001] The present invention relates to a device, a kit and a method for detecting unevenness and / or obstacles in a field. It applies, in particular, to the field of agriculture and viticulture. State of the art

[0002] Fields, such as those of fruit trees or vines, are organized in rows. In order to maintain the field, it is necessary to work the soil close to the plantations without damaging them. If the tractor pulling the field working tool shifts, or if the planting width or slope changes, adjusting the width or depth of the working tool can have serious consequences on the crops, especially if the settings are fixed.

[0003] There is currently no solution to effectively detect irregularities in a field. Summary of the invention

[0004] The present invention aims to remedy all or part of these drawbacks.

[0005] The present invention aims to have an adjustment and control of the width or automatic depth control so that the tool always maintains the same working width or depth. The present invention is an automatic width adjustment, re-centering and depth control system that fits on any tool holder and allows the user to control the working width as well as the working depth.

[0006] The present invention protects the plantations, and at the same time, the user, because the latter, being sure of working in good conditions, will not have to turn around constantly and will be able to adopt a better driving position and thus avoid musculoskeletal disorders. Brief description of the figures

[0007] Other advantages, aims and particular characteristics of the invention will emerge from the following non-limiting description of at least one particular embodiment of the device, kit and method which are the subject of the present invention, with reference to the appended drawings, in which:

[0008] [Fig. 1] represents, schematically and in perspective, a first particular embodiment of the device which is the subject of the present invention,

[0009] [Fig.2] represents, schematically and in top view, the first mode of particular embodiment of the device which is the subject of the present invention,

[0010] [Fig.3] represents, schematically and in side view, the first embodiment particular of the device which is the subject of the present invention and

[0011] [Fig.4] represents, schematically and in the form of a flowchart, a first mode for carrying out a method which is the subject of the present invention. Description of the embodiments

[0012] 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.

[0013] The expression "and / or", as used herein and in the claims, is to be understood to mean "either or both" of the elements so conjoined, i.e., elements which are present conjunctively in some cases and disjunctively in other cases. Multiple elements listed with "and / or" are to be interpreted in the same way, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present, other than the elements specifically identified by the "and / or" clause, whether or not they are related to these specifically identified elements.Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with open language such as "comprising" may refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0014] As used herein in the description and in the claims, "or" is to be understood as having the same meaning as "and / or" as defined above. For example, when separating elements in a list, "or" or "and / or" is to be interpreted as inclusive, i.e., the inclusion of at least one, but also more than one, number or list of elements, and, optionally, additional elements not listed. Only terms clearly indicating the contrary, such as "only one of" or "exactly one of", or, when used in the claims, "consisting of", refer to the inclusion of only one element of a number or list of elements.

[0015] As used in this specification and in the claims, the expression "at least one", with reference to a list of one or more elements, should be understood to mean at least one element selected from one or more elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than the elements specifically identified in the list of elements to which the phrase "at least one" refers, whether or not related to those specifically identified elements.Thus, by way of non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer, in one embodiment, to at least one, optionally including more than one, A, without B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, without A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0016] In the claims, as well as in the description below, all transitional expressions such as "comprising", "including", "carrying", "having", "containing", "involving", "holding", "consisting of", and the like, are to be understood as being open, i.e., as meaning including, but not limited to. Only the transitional expressions "consisting of" and "consisting essentially of" are to be understood as closed or semi-closed transitional expressions, respectively.

[0017] It should be noted from now on that figures 1 to 3 are to scale.

[0018] We observe, in figures 1, 2 and 3, which are to scale, but at scales different, a schematic view of an embodiment of the device 100 which is the subject of the present invention.

[0019] The device 100 for detecting unevenness and / or obstacles in a field comprises a chassis. The chassis comprises three parallel crosspieces, 107, 108 and 109. The crosspieces, 107, 108 and 109, are preferably made of a metal alloy, for example stainless steel or aluminum alloy. The crosspieces, 107, 108 and 109, are straight metal profiles with a hollow rectangular section arranged in parallel. The crosspieces, 107, 108 and 109, may have any other section known to those skilled in the art.

[0020] The crosspieces, 107, 108 and 109 are fixed to three slides, 101, 102 and 103. The slide 101 is made of a straight metal profile with a hollow rectangular section.

[0021] The slides, 102 and 103, have a section in the shape of two U-shaped sections placed side by side. A U-shaped section comprises two parallel arms and a junction perpendicular to the two arms joining one end of each arm so as to form a channel. The U-shaped sections of the slides, 102 and 103, are arranged in such a way that the openings between the arms of each section are on the same side. In embodiments, the U-shaped sections have a flap at the end of each arm configured to hold a slide, 201, 202, 203 or 204, in the U-shaped section.

[0022] The slides, 102 and 103, are preferably obtained by joining two U-shaped section profiles, by welding or any other mechanical connection known to those skilled in the art.

[0023] In embodiments, the sliders, 102 and 103, may have any other shape compatible with the production of a sliding connection.

[0024] The sliders, 101, 102 and 103 are arranged perpendicular to the crosspieces, 107, 108 and 109, and form a plane configured to be substantially parallel to the ground when the device is in use.

[0025] The chassis comprises two parts which move in translation relative to the slides, 101, 102 and 103, on either side of the slides, 101, 102 and 103.

[0026] The first part movable in translation comprises a crosspiece 131 connected to three slides: - a first slide 130 of a shape corresponding to the slide 101 and forming a sliding connection with the slide 101, - a second slide 201 of a shape corresponding to the slide 102 and forming a sliding connection with the slide 102, - a second slide 203 of a shape corresponding to the slide 103 and forming a sliding connection with the slide 103.

[0027] The crosspiece 131 therefore moves parallel to the crosspieces 107, 108 and 109 of the chassis.

[0028] The second part movable in translation comprises a crosspiece 111 connected to three slides: - a first slide 110 of a shape corresponding to the slide 101 and forming a sliding connection with the slide 101, - a second slide 202 of a shape corresponding to the slide 102 and forming a sliding connection with the slide 102, - a second slide 204 of a shape corresponding to the slide 103 and forming a sliding connection with the slide 103,

[0029] The crosspiece 111 therefore moves parallel to the crosspieces 107, 108 and 109 of the chassis.

[0030] The slides, 110, 130, 201 to 204, are preferably made of metal alloy.

[0031] Preferably, at least one first slide, 110 and 130, comprises a means for adjusting a lateral position. For example, the position adjustment means lateral can be a hydraulic or pneumatic cylinder fixed on the one hand to the slide, 110 or 130, and on the other hand to the slide 102.

[0032] Lateral is what is in a direction parallel to the axis of the slide 102.

[0033] Preferably, each moving part comprises a tool, 116 or 136. The means for adjusting the lateral position described above is then a means for modifying the relative position of the at least one tool, 116 or 136, with respect to the chassis.

[0034] Preferably, the relative position of the tool, 116 or 136, with respect to the chassis is measured by a position measuring means 106, such as a ruler or a counter configured to detect a position as a function of a number of stepper motor revolutions performed.

[0035] The tool 116 or 136 is fixed to the crosspiece, 111 or 131, of each moving part by means of a pivot connection, 114 or 134, with an axis perpendicular to the crosspieces, 107, 108 and 109, and to the slides, 101, 102 and 103. For example, each crosspiece, 111 or 131, of each moving part may comprise a tool support rod, fixed by a removable fixing means, 112 or 132. The rod, with an axis parallel to the axis of the pivot connection, may be provided with an electric motor, 113 or 133. The motor, 113 or 133, rotates the tool, 116 or 136, along the axis of the pivot connection. Each motor can then be a means of modifying the relative position of the at least one tool with respect to the chassis. Furthermore, each motor preferably comprises a means of measuring a position of the tool, 116 or 136, with respect to the chassis.

[0036] In the embodiment shown, the tool, 116 or 136, is a mower equipped with a side protection 117 to prevent dangerous projections.

[0037] Preferably, the tool, 116 or 136, comprises a means for detecting an obstacle comprising a flexible part deforming upon contact with an obstacle and a sensor for detecting the deformation of the flexible part. For example, the flexible part may be a rounded feeler, 115 or 135, at least partially circumscribing the tool, 116 or 136. The feeler, 115 or 135, may be attached to a spring. When the feeler, 115 or 135, comes into contact with an obstacle, the feeler, 115 or 135, moves and deforms the spring, which actuates a sensor for detecting the deformation of the flexible part. Once the obstacle has passed, the feeler is returned to its initial position by the spring.

[0038] The deformation sensor of the flexible part may be a push button on which the spring and / or the feeler, 115 or 135, actuates following a deformation.

[0039] In embodiments not shown, the obstacle detection means is a proximity sensor, for example an infrared sensor.

[0040] The chassis also comprises two wheels, 123 and 143, fixed to the slider 103 by a sliding connection, 121 and 141, with an axis perpendicular to the axis of the sliding connection, 121 and 141, formed by the slider 103 and to the axis of each crosspiece, 107, 108 and 109. The sliding connection, 121 and 141, is provided with a positioning means of the wheel, 123 or 143, such as a pneumatic or hydraulic cylinder, for example. The wheel positioning means is configured to position the wheel at a predetermined distance from the ground. Such positioning means may be a means for modifying the relative position of the wheel and the at least one tool relative to the chassis.

[0041] At least one mobile part comprises a means for detecting a difference in level comprising a wheel 119 resting on the ground and a contact sensor 120 of the wheel on the ground. In the embodiment shown in Figures 1 to 3, the means for detecting a difference in level 120 is fixed to the crosspiece 111. The means for detecting a difference in level may be any means for detecting a translation according to a sliding connection. Preferably, the means for detecting a difference in level comprises a spring configured to push the wheel 119 towards the ground.

[0042] The device 100, object of the present invention also comprises a control means 150 configured to control the modification of the position of the wheel 119 and / or of the at least one tool 116 and / or 136: - when an obstacle is detected and / or - when a lack of contact of wheel 119 on the ground is detected.

[0043] The control means can receive at least one piece of information representing a value from among: - a value representative of a position measurement from the position measuring means 106, - a value representative of a measurement of the tool position, 116 or 136, relative to the chassis, - a value representative of the detection or absence of an obstacle, from the detection means 115, - a value representative of the positioning of the wheels 123 and 143 and / or, - a value representative of an absence of contact of the wheel 119 on the ground, from the sensor 120.

[0044] The control means can transmit commands: - modification of a position of each moving part relative to the chassis, for example defined by the user by means of a human-machine interface or from a computer memory 151, the modification being implemented by the means of adjusting the lateral position, - modification of the position of the tool, 116 or 136, relative to the chassis, when an obstacle is detected, the modification of the position being carried out by the motor 114 and / or 134, - modification of the positioning of the wheels when a difference in level is detected, that is to say in the event of absence of contact of the wheel 119 on the ground, the modification being implemented by the cylinders of the sliding connections, 121 and 141, - configuration of the positioning of the wheels, 123 and 143, for example defined by the user by means of a human-machine interface or from a computer memory 151, the configuration being implemented by the cylinders of the sliding connections, 121 and 141, and / or - configuration of the position of the tool, 116 or 136, relative to the chassis, for example defined by the user by means of a human-machine interface or from a computer memory 151, the configuration being implemented by at least one means of modifying the relative position of the at least one tool relative to the chassis.

[0045] The commands and values can be transmitted wired or not by a communication means 154 of the control means 150.

[0046] Preferably, the control means comprises a means 152 for adjusting a lateral position of each obstacle detection means 115 and 135 relative to the chassis. The adjustment means 152 then controls the motor, 113 or 133, into position, for example to correspond to the distance between two rows of a field.

[0047] In embodiments, the control means comprises a means 151 for storing a lateral position before the detection of an obstacle, the control means 150 being configured to: - retract at least one tool, 116 or 136, when an obstacle is detected and - in the absence of an obstacle, reposition at least one tool, 116 or 136, to the lateral position stored before detecting an obstacle.

[0048] Retracting is the modification of the position of at least one tool, 116 or 136, to increase the compactness of the device 100.

[0049] When a difference in level is detected, the cylinders of the sliding links, 121 and 141, are actuated so that the position of the tool relative to the ground remains substantially constant, whatever the difference in level.

[0050] In other words, the position before the detection of an obstacle is memorized so that the tool can resume this position once the obstacle has passed. The storage means 151 is, for example, a computer memory.

[0051] In embodiments, the device 100 further comprises means for measuring a lateral dimension of the at least one tool, 116 or 136, and in which the lateral position of each obstacle detection means, 115 or 135, relative to the chassis is adjusted as a function of the measured lateral dimension. For example, the means for measuring a lateral dimension may be a detector of the tool mounted on the chassis associating each tool with dimensions in a database.

[0052] In embodiments, the control means 150 further comprises a means 153 for recording the position of the at least one tool, 116 and 136, relative to the chassis. The recording means 153 may be a computer memory. Preferably, the control means is configured to position the at least one tool, 116 or 136, in the last recorded position.

[0053] In embodiments, the recording means 153 can associate with at least one field, at least one geolocated value among: - a value representative of a position measurement from the position measuring means 106, - a value representative of a measurement of the tool position, 116 or 136, relative to the chassis, - a value representative of the detection or absence of an obstacle, - a value representative of the positioning of the wheels 123 and 143 and / or, - a value representative of an absence of contact of the wheel 119 on the ground.

[0054] A field is, for example, represented geometrically as a plot in a computer memory, for example the storage means 151.

[0055] Preferably, the control means 150 communicates with a geolocation means.

[0056] In embodiments, a human-machine interface communicating with the control means 150 is configured to transmit commands: - for configuring the positioning of the wheels, 123 and 143, for example defined by the user by means of a human-machine interface or originating from a computer memory 151, and / or - configuration of the position of the tool, 116 or 136, relative to the chassis, for example defined by the user by means of a human-machine interface or from a computer memory 151.

[0057] The configuration of the positioning of the wheels, 123 and 143, is preferably implemented by the cylinders of the sliding connections, 121 and 141. The configuration of the position of the tool relative to the chassis is implemented by at least one means of adjusting the lateral position and / or one means of modifying the relative position of the tool relative to the chassis.

[0058] The present invention may be arranged in the form of a kit to form a device 100 for detecting differences in level and / or obstacles in a field, which comprises: - at least one means of attachment to a chassis, - at least one means of detecting an obstacle, 115 and / or 135, - at least one means for detecting a difference in level comprising a wheel 119 resting on the ground and a sensor 120 for contact between the wheel and the ground, - a means of modifying, 113, 133, the relative position of the wheel and / or at least one tool with respect to the chassis, - a control means 150 configured to control the modification of the position of the wheel 119 and / or of at least one tool, 116 and / or 136: - when an obstacle is detected and / or - when a lack of contact of wheel 119 on the ground is detected.

[0059] [Fig.4] represents a method 40 for detecting differences in level and / or obstacles in a field, which comprises: - a step 43 of detecting an obstacle, - a step 44 of detecting a difference in level by means of a means of detecting a difference in level comprising a wheel 119 resting on the ground and a sensor 120 of contact of the wheel on the ground, - a control step 45 for modifying the position of a wheel and / or at least one tool: - when an obstacle is detected and / or - when a lack of contact between the wheel and the ground is detected, - a step 46 of modifying the relative position of the wheel and / or of the at least one tool with respect to the chassis.

[0060] The method 40 may comprise optional steps of: - configuration 41 of the positioning of the wheels, 123 and 143, for example defined by the user by means of a human-machine interface or from a computer memory 151, and / or - configuration 42 of the position of the tool, 116 or 136, relative to the chassis, for example defined by the user by means of a human-machine interface or from a computer memory 151.

[0061] Preferably, the means of the device 100 and of the kit are configured to implement the steps of the method 40 and their embodiments as set out above and the method 40 as well as its different embodiments can be implemented by the means of the device 100. Presentation of the invention

[0062] According to a first aspect, the present invention relates to a device for detecting differences in level and / or obstacles in a field, which comprises: - a chassis comprising: - at least one tool, - at least one means of detecting an obstacle, - at least one means of detecting a difference in level comprising a wheel resting on the ground and a sensor for contact between the wheel and the ground, - a means of modifying the relative position of the wheel and / or of the at least one tool with respect to the chassis, - a control means configured to control the modification of the position of the wheel and / or of the at least one tool: - when an obstacle is detected and / or - when a lack of contact between the wheel and the ground is detected.

[0063] Thanks to these provisions, it is possible to detect plantations and retract a soil working tool. The plantations, for example trees and / or vines, are therefore not damaged. In addition, in order to have a more efficient soil working tool, local unevenness is detected and the tool can therefore be repositioned to always penetrate the soil sufficiently.

[0064] In embodiments, the control means comprises means for adjusting a lateral position of each obstacle detection means relative to the chassis.

[0065] Thanks to these provisions, the device is adaptable to fields in which the plantations are in rows, whatever the dimension between two rows.

[0066] In embodiments, the control means comprises a means for storing a lateral position before the detection of an obstacle, the control means being configured to: - retract at least one tool when an obstacle is detected and - in the absence of an obstacle, reposition at least one tool to the lateral position stored before detecting an obstacle.

[0067] With these provisions, when a plantation is detected, the tool is re-traced to protect the plantation and then repositioned to work between the plantations.

[0068] In embodiments, the device which is the subject of the present invention further comprises a means for measuring a lateral dimension of the at least one tool, and in which the lateral position of each obstacle detection means relative to the chassis is adjusted as a function of the measured lateral dimension.

[0069] Thanks to these provisions, the device is adapted to the dimensions of the soil working tool which may differ from one manufacturer to another.

[0070] In embodiments, the device which is the subject of the present invention further comprises a means for recording the position of the at least one tool relative to the chassis.

[0071] Thanks to these provisions, when the user stops for the day or for a break, the position of the tool is memorized.

[0072] In embodiments, the control means is configured to position the at least one tool in the last recorded position.

[0073] Thanks to these provisions, when the user stops for the day or for a break, the stored tool position makes it possible to reconfigure the tool position to restart the soil treatment more quickly.

[0074] In embodiments, the means for modifying the relative position of the wheel and the at least one tool with respect to the chassis comprises at least one hydraulic cylinder.

[0075] Thanks to provisions, the device is reactive and can therefore quickly catch up with the detected difference in level or quickly retract the obstacle detection means and / or the tool.

[0076] In embodiments, the obstacle detection means comprises a flexible part deforming upon contact with an obstacle and a deformation sensor of the flexible part.

[0077] Thanks to these provisions, the device is robust and resistant to possible fouling during soil work.

[0078] In embodiments, the obstacle detection means is a proximity sensor.

[0079] Thanks to these provisions, any contact with the plantations is avoided, they are thus preserved.

[0080] According to a second aspect, the present invention aims at a method for detecting differences in level and / or obstacles in a field, which comprises: - an obstacle detection step, - a step of detecting a difference in level by means of a means of detecting a difference in level comprising a wheel resting on the ground and a sensor for contact of the wheel on the ground, - a step of controlling a modification of the position of a wheel and / or at least one tool: - when an obstacle is detected and / or - when a lack of contact between the wheel and the ground is detected, - a step of modifying the relative position of the wheel and / or of the at least one tool in relation to the chassis.

[0081] The aims, advantages and particular characteristics of the method which is the subject of the present invention being similar to those of the device which is the subject of the present invention, they are not recalled here.

[0082] According to a third aspect, the present invention relates to a kit for forming a device for detecting differences in level and / or obstacles in a field, which comprises: - at least one means of attachment to a chassis, - at least one means of detecting an obstacle, - at least one means of detecting a difference in level comprising a wheel resting on the ground and a sensor for contact between the wheel and the ground, - a means of modifying the relative position of the wheel and / or at least one tool in relation to the chassis, - a control means configured to control the modification of the position of the wheel and / or at least one tool: - when an obstacle is detected and / or - when a lack of contact between the wheel and the ground is detected.

[0083] The aims, advantages and particular characteristics of the kit which is the subject of the present invention being similar to those of the device which is the subject of the present invention, they are not recalled here.

Claims

Claims

1. Device (100) for detecting unevenness and obstacles in a field, characterized in that it comprises: - a chassis comprising: - two wheels (123, 143), - at least one tool (116, 136), - at least one means for detecting an obstacle (115, 135), - at least one means for detecting an unevenness comprising another wheel (119) resting on the ground and a contact sensor (120) of this other wheel (119) on the ground, - a means for modifying (121, 141, 114, 134, 113, 133) the relative position of said two wheels (123, 143) and / or of the at least one tool relative to the chassis, - a control means (150) configured to: * control the modification of the position of the at least one tool when an obstacle is detected, and * control the modification of the position of said two wheels (123, 143) relative to the chassis when an absence of contact of said other wheel (119) on the ground is detected.

2. Device (100) according to claim 1, wherein the control means (150) comprises means (152) for adjusting a lateral position of each obstacle detection means relative to the chassis.

3. Device (100) according to claim 2, wherein the control means (150) comprises a means (151) for storing a lateral position before the detection of an obstacle, the control means being configured to: - retract at least one tool when an obstacle is detected and - in the absence of an obstacle, reposition the at least one tool to the lateral position stored before the detection of an obstacle.

4. Device (100) according to one of claims 2 or 3, which further comprises a means (106) for measuring a lateral dimension of the at least one tool (116, 136), and in which the lateral position of each obstacle detection means (115, 135) relative to the chassis is adjusted as a function of the measured lateral dimension.

5. Device (100) according to one of claims 1 to 4, which further comprises means (153) for recording the position of the at least one tool (116, 136) relative to the chassis.

6. Device (100) according to claim 5, wherein the control means (150) is configured to position the at least one tool (116, 136) in the last recorded position.

7. Device (100) according to one of claims 1 to 6, in which the means for modifying (121, 141, 114, 134, 113, 133) the relative position of said two wheels (123, 143) and of the at least one tool (116, 136) with respect to the chassis comprises at least one hydraulic cylinder.

8. Device (100) according to one of claims 1 to 7, in which the obstacle detection means (115, 135) comprises a flexible part deforming upon contact with an obstacle and a sensor for deforming the flexible part.

9. Method (40) for detecting differences in level and obstacles in a field, characterized in that it comprises: - a step of detecting (43) an obstacle, - a step of detecting (44) a difference in level by means of a means of detecting a difference in level, - a control step (45) configured to control the modification of the position of two wheels (123, 143) and / or at least one tool: - when an obstacle is detected and / or - when an absence of contact of another wheel (119) on the ground is detected, the means of detecting a difference in level comprising this other wheel (119) resting on the ground and a sensor (120) of contact of said other wheel (119) on the ground, - a step of modifying (46) the relative position of said two wheels (123, 143) and / or of the at least one tool with respect to the chassis.

10. Kit for forming a device for detecting differences in level and obstacles in a field, characterized in that it comprises: - at least one means of attachment to a chassis, - two wheels (123, 143), - at least one means of detecting an obstacle (115, 135), - at least one means of detecting a difference in level comprising another wheel (119) resting on the ground and a contact sensor (120) of this other wheel (119) on the ground, - a means (121, 141, 114, 134, 113, 133) for modifying the relative position of said two wheels (123, 143) and / or of the at least one tool relative to the chassis, - a control means (150) configured to: * command the modification of the position of at least one tool when an obstacle is detected, and * controlling the modification of the position of said two wheels (123, 143) relative to the chassis when an absence of contact of said other wheel (119) on the ground is detected.

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