Wired drone for treating a surface by spraying a treatment fluid

Abstract

The invention relates to a wired drone (100) for treating a surface (200), comprising: - a propulsion system, and - a fluid spraying system. The drone is essentially characterised in that it comprises: - a first sonar (110), - a second sonar (120), and - an arithmetic unit configured to: determine the distance between each sonar and the surface (200); calculate the difference between the measurement of the first sonar (110) and of the second sonar (120); and deduce therefrom: - the yaw angle of the drone (100), and - the distance of the drone (100) from the surface (200); and control the position of the drone (100) by the difference between: - the calculated distance and a predetermined distance setpoint, and - the calculated yaw angle of the drone (100) and a predetermined yaw angle setpoint of the drone (100).

Description

[0001] Wired drone for treating a surface by spraying a treatment fluid.

[0002] The present invention relates to surface treatment in the field of construction, maintenance, cleaning and renovation. The surface to be treated can be of any type, whatever its covering, facade or roof of buildings, whether residential (individual house, apartment building) or professional (offices, factories, silos etc.), or more generally any flat or non-flat surface which has a height greater than 2m, and for example a wind turbine, both its mast and its blades.

[0003] In this field, it is common to have to carry out risky tasks such as working at height or even on dangerous materials or substances, for example carcinogenic, mutagenic and toxic for reproduction (CMR).

[0004] In particular, risky tasks involve projecting fluid, liquid or gaseous products onto building surfaces.

[0005] Document FR3048415 is known. However, the device presented there requires a telescopic mast and a camera on it, which is impractical. Document W02020021305 is also known, but this requires support means to keep a drone in contact with the surface to be treated.

[0006] The applicant also filed application FR3125017 in this area.

[0007] In this field, it has been observed by the applicant that the mist generated by the spraying of a fluid disrupts the distance sensors.

[0008] The present invention aims in particular to address this problem.

[0009] SUMMARY OF THE INVENTION

[0010] In this context, more specifically, the invention relates, according to a first of its objects, to a wired drone (100) for treating a surface (200) by spraying a treatment fluid, the drone (100) comprising:

[0011] - a propulsion system, comprising a set of engines, front propellers and rear propellers,

[0012] - a treatment fluid projection system comprising a set of at least one spray nozzle for spraying, preferably under high pressure, said treatment fluid, said set comprising a solenoid valve and being connected to a sealed sheath for supplying treatment fluid,

[0013] - a set of at least one distance sensor.

[0014] The set of at least one distance sensor includes:

[0015] - a first sonar (110), configured to measure the distance between said first sonar (110) and said surface (200),

[0016] - a second sonar (120), preferably identical to the first sonar (110), oriented in the same direction as the first sonar (110) and configured to measure the distance between said second sonar (120) and said surface (200), the drone (100) further comprising:

[0017] - a computing unit, configured to:

[0018] • measuring the distance between said first sonar (110) and said surface (200);

[0019] • measuring the distance between said second sonar (120) and said surface (200);

[0020] • calculate a differential measurement between the measurement of the first sonar (110) and the measurement of the second sonar (120); deduce from this:

[0021] - the yaw angle of the drone (100) relative to a normal to the surface (200), and

[0022] - the distance from the drone (100) to the surface (200);

[0023] • and control the position of the drone (100) relative to the surface (200) by difference between:

[0024] - the calculated distance and a predetermined calculated distance, and

[0025] - the calculated drone yaw angle (100) and a predetermined drone yaw angle setpoint (100).

[0026] It is essentially characterized in that: the drone (100) comprises an autopilot system comprising a general servo device which comprises a first PID regulator and which allows servo control in roll, yaw and pitch, and in which the calculation unit, which comprises a second PID regulator distinct from the first PID regulator, is configured to servo control the position of the drone (100) relative to the surface (200) by difference between:

[0027] • the calculated distance and a predetermined distance instruction, and

[0028] • the calculated drone yaw angle (100) and a drone yaw angle setpoint (100).

[0029] Thanks to the invention, the spraying of the treatment fluid can be implemented at a constant flow rate. Maintaining the drone at a set distance coupled with a predetermined yaw angle ensures the effectiveness of the spraying when the drone flies in vertical passes.

[0030] It can be provided that the calculation unit is configured to control the position of the drone (100) relative to said surface (200) so that the difference between the calculated yaw angle of the drone (100) and the yaw angle setpoint is equal to 0.

[0031] This feature makes spraying the treatment fluid more efficient, especially with spray nozzles that project in a cone or triangle pattern.

[0032] It can be provided that the first sonar (110) and second sonar (120) are symmetrical to each other with respect to a longitudinal plane of symmetry.

[0033] This feature makes position keeping calculations simpler.

[0034] It can be provided that the activation of the treatment fluid projection system is controlled by the position of the drone (100) relative to the surface (200).

[0035] Thanks to this feature, spraying can only start when the drone is in an effective position, which saves the consumption of treatment fluid.

[0036] It can be provided that the set of at least one distance sensor further comprises at least one of the following sensors:

[0037] • a set of at least one third sonar;

[0038] • a set of at least one stereo camera, the detection distance of which is greater than the detection distance of the first sonar (110), the second sonar (120) or the third sonar.

[0039] It can be provided that the set of at least one distance sensor further comprises at least one lidar (360), the detection distance of which is greater than the detection distance of the stereo camera.

[0040] Thanks to this feature, the position of the drone is known in detail in that each sensor is activated according to the distance to the determined surface and the range of said sensor. In addition, thanks to the stereo camera or the lidar, it is possible to generate a point cloud, from which a plane can be extracted, therefore a distance to the plane and a normal to the plane, thanks to known algorithms, sometimes integrated, in particular in certain stereo cameras.

[0041] It is also possible to provide automatic piloting means, so that the drone (100) is autonomous or semi-autonomous.

[0042] It can be provided that the drone (100) comprises an autopilot system comprising a general servo-control device for the drone (100) in roll, yaw and pitch, and in which the calculation unit, which comprises a PID regulator separate from the general servo-control device for the drone (100) in roll, yaw and pitch, is configured to servo-control the position of the drone (100) relative to the surface (200) by difference between:

[0043] • the calculated distance and a predetermined distance instruction, and

[0044] • the calculated drone yaw angle (100) and a drone yaw angle setpoint (100).

[0045] Thanks to this feature, a standard drone can be adapted to implement the invention.

[0046] It can be provided that the accuracy of the position of the drone (100) relative to said surface (200) is 5 cm + / - 10% over a position range of the assembly of at least one spray nozzle between 5 cm and 90 cm from said surface (200).

[0047] Thanks to this feature, the implementation of surface treatment with a drone according to the invention is particularly effective.

[0048] According to another of its objects, the invention relates to a method for treating a surface (200) with a treatment fluid, using a wired drone (100) according to the invention, the method comprising steps consisting of:

[0049] - detecting the distance from the drone (100) to said surface (200),

[0050] - detect the yaw angle of the drone (100) relative to a normal to the surface (200),

[0051] - control the position of the drone (100) relative to the surface (200) by difference between:

[0052] • the detected distance and a predetermined distance setpoint, and

[0053] • the detected yaw angle of the drone (100) and a predetermined yaw angle setpoint of the drone (100), the method further comprising at least one of the steps consisting of:

[0054] - create a depth map using measurements from at least one distance sensor,

[0055] - detecting defects on said surface (200) using measurements from the assembly of at least one distance sensor, and

[0056] - spraying, preferably under high pressure, a treatment fluid onto said surface (200).

[0057] For the purposes of the present invention, the verbs: detect, measure and determine are understood indistinctly.

[0058] Advantageously, the present invention only implements a single drone, and not a fleet of drones.

[0059] The drone according to the invention can advantageously be implemented in constrained urban environments, even inhabited ones and a few centimeters from the facades, in the field of building, construction or renovation. It can also be implemented in the audiovisual, industry, agriculture, etc.

[0060] Other characteristics and advantages of the present invention will appear more clearly on reading the following description given by way of illustrative and non-limiting example and made with reference to the appended figures.

[0061] DESCRIPTION OF THE DRAWINGS

[0062] [Fig. 1] illustrates the local reference of a drone according to the invention,

[0063] [Fig. 2] illustrates a top view of a drone according to the invention,

[0064] [Fig. 3] illustrates in top view a drone according to the invention having a certain yaw,

[0065] [Fig. 4] illustrates the drone of Figure 3 in profile view.

[0066] DETAILED DESCRIPTION

[0067] The solution according to the invention comprises a drone 100. The drone 100 comprises a propulsion system, known per se, which comprises a set of engines, front propellers and rear propellers and which will not be described further. The drone 100 also comprises a treatment fluid projection system, also known per se, for example from application FR3125017 filed by the applicant. The treatment fluid projection system comprises a set of at least one spray nozzle for spraying, preferably under high pressure (100-130 bars), said treatment fluid, said set comprising a solenoid valve and being connected to a sealed sheath for supplying treatment fluid.

[0068] The drone 100 also includes a computing unit, described later.

[0069] Preferably, the drone 100 comprises automatic piloting means, so that the drone 100 is autonomous or semi-autonomous.

[0070] For example, the drone 100 is of the rotorcraft type (generally a quadcopter or an octorotor), which in flight must remain at a predetermined fixed distance from a surface 200 to be treated.

[0071] For brevity, the surface 200 to be treated is referred to as “the surface”.

[0072] The surface 200 may be flat or curved and is generally vertical, that is to say it may be strictly vertical or have an inclined face, or even a polygonal structure.

[0073] If the drone 100 moves forward or backward relative to the predetermined distance to the surface 200, whether due to the inaccuracy of its inertial unit (IM U), its satellite positioning system (GNSS) or due to an external disturbance (wind), it is imperative that it automatically repositions itself at the predetermined distance, without oscillations, relatively quickly, and avoiding a collision with the surface 200.

[0074] This maintenance at a predetermined distance helps to better manage the problems of treating a surface 200, in particular by high-pressure spraying. Indeed, depending on the nozzles and the pressure used, beyond a threshold distance, for example more than 10 cm from the surface 200, a high-pressure jet may no longer strip; and at less than 3 cm, there is a risk of tearing off the coating of the surface 200 (for example, plaster).

[0075] Spraying, especially high pressure, generates a fog, a spray mist, which is even more significant near the surface 200 since the droplets are partly reflected by the surface 200. This spray mist disturbs a camera or a lidar, and can disturb the magnetic compass of a drone 100, even if only water is sometimes sprayed.

[0076] Additionally, in the case of spraying cleaning products, the cleaning products that are sprayed may have some viscosity and tend to stick to the sensors.

[0077] The present invention makes it possible to overcome this problem in a constrained external environment, in particular thanks to sonars which are not disturbed by the spray mist.

[0078] The environment in which the drone 100 operates is said to be "constrained" because of the very structure of the surface 200 to be treated or the surrounding surfaces which may mask the GPS signal or disturb the Earth's magnetic field, for example because of metal structures, or because of movements of wind turbine blades, etc. The structure of the surface 200 may be complex due to the very architecture of a building which includes, for example, balconies, windows, antennas, vegetation, etc. as well as facades with inclined sides. It is therefore necessary to compensate for the variation in the distance to the surface 200 permanently, so that the distance to the facade is substantially constant, controlled by the sensors, as described later.

[0079] The drone 100 has a local reference frame illustrated in Figure 1.

[0080] The X axis is the roll axis, it is the axis of movement left / right;

[0081] The Y axis is the pitch axis, it is the forward / backward movement axis; and

[0082] The Z axis is the yaw axis, it is the vertical axis of rotation.

[0083] In this case, it is desired that the drone 100 remains at a predetermined fixed distance in x and that its x axis is perpendicular to the surface 200, considering the surface 200 to be locally flat.

[0084] The drone 100 must therefore be constrained in pitch and yaw: In pitch to ensure a fixed distance to the surface 200. In yaw to ensure perpendicularity to the surface 200. By "yaw angle", we mean the angle between the vector of the X axis of the drone (the heading of the drone) and a vector normal to the surface 200.

[0085] By "yaw control" we mean an angular velocity command to turn the drone on its yaw axis.

[0086] The distance from the drone 100 to the surface 200 can be estimated by a distance sensor. However, if the drone 100 is not perpendicular to the surface 200, i.e., if the X axis is not parallel to the normal to the surface 200, then the distance measurement is erroneous.

[0087] Advantageously according to the invention, a set of at least two distance sensors is preferably implemented.

[0088] According to the invention, the set of at least two distance sensors comprises a first sonar 110 and a second sonar 120, preferably identical to the first sonar 110.

[0089] Sonars are advantageous because their measurements are more accurate than those of a camera; and unlike lidars, sonar measurements are not disrupted by reflective surfaces such as reflective or transparent windows.

[0090] In this case, the distance sensors are front sensors, located beyond the blades.

[0091] Preferably, the first sonar 110 and the second sonar 120 are symmetrical to each other with respect to a longitudinal plane of symmetry P, as illustrated in FIG. 2.

[0092] The first sonar 110 is configured to measure the distance between said first sonar 110 and said surface 200.

[0093] The second sonar 120 is preferably oriented in the same direction as the first sonar 110 and configured to measure the distance between said second sonar 120 and said surface 200.

[0094] Using the measurements of the first sonar 110 and the second sonar 120, the computing unit can determine the distance between said first sonar 110 and the surface 200 and the distance between said second sonar 120 and the surface 200. If the second sonar 120 is identical to the first sonar 110 and the drone 100 is perpendicular to the surface 200, then the measurements of the first sonar 110 and the second sonar 120 are the same.

[0095] By calculating a differential measurement between the measurement of the first sonar 110 and the measurement of the second sonar 120, the calculation unit is capable of determining:

[0096] On the one hand the yaw angle of the drone 100, and on the other hand the distance of the drone 100 to the surface 200.

[0097] With D1 the value of the distance from the first sonar 110 to the surface 200, and D2 the value of the distance from the second sonar 120 to the surface 200: the yaw angle of the drone 100 relative to a normal to the surface 200 can be calculated. This is in fact the angle of the surface normal relative to the X axis of the drone. In practice, a yaw angular speed setpoint is obtained after the PID loop described later, thanks to the difference between the two distances of the first sonar and the second sonar; the distance of the drone 100 to the surface 200 can be estimated by the smaller of these two distance values ​​D1 and D2, i.e. min(D1, D2), or by trigonometric calculation since the distance between the first sonar 110 and the second sonar 120 is known.

[0098] Without calculating the value of the yaw angle, we can also simply determine whether the drone 100 is perpendicular to the surface 200 by simple difference a = D1-D2, as illustrated in Figure 3. If this value a is zero, the two sonars are at the same distance from the surface 200 and the drone 100 is locally perpendicular to the surface 200. If the error a is negative, the drone 100 points too far to the left and vice versa when the error a is positive.

[0099] For the flight, the drone 100 receives: a predetermined yaw angle instruction from the drone 100, typically with a value equal to 0; and a predetermined distance instruction from the surface 200.

[0100] Preferably, a tolerance Ex of the positioning in X around the distance setpoint to the surface 200 De is provided, with preferably Ex =< De; with reference to figure 4.

[0101] The distance D from drone 100 to surface 200 is estimated by value D = min(D2, D1). To control the X distance from drone 100, we can calculate the value 5 = D-Dc = min(D2, D1) - De. If the value 5 is positive, then it means that drone 100 is too far from surface 200; and if the value 5 is negative, then it means that drone 100 is too close.

[0102] In this case, a PID regulator is provided, which implements a PID loop, to control the drone 100 in pitch and yaw to the surface 200. Preferably, to avoid control overloads, the pitch control is implemented before the yaw control.

[0103] Typically, a standard drone includes an autopilot system comprising a general servo device (roll, yaw and pitch) which includes a first PID regulator, known per se and supplied with most standard drones. This first PID regulator allows self-stabilization of the flight, but without reference to a facade, nor GPS.

[0104] According to the invention, a second PID regulator is provided. The second PID regulator of the invention is separate from this first PID regulator, and additional to it. A drone according to the invention therefore comprises 2 PID regulators: a standard PID regulator for flight stabilization and a PID regulator according to the invention, which allows control of pitch and yaw relative to the normal to a surface.

[0105] The second PID controller according to the invention allows control of the drone based on the calculation of an error or on a measurement. Two values ​​can be calculated which can be positive or negative depending on the orientation of the drone, and which must tend towards 0 thanks to the PID controller.

[0106] 1. The first measurement is directly the yaw angle.

[0107] According to the definition of the yaw angle, if it is equal to zero, the first sonar and the second sonar are aligned, so the drone is perpendicular to the surface 200, in good condition for the treatment of the surface 200. If the yaw angle is negative or positive, an angular velocity instruction is given to rotate the drone around the Z axis, in a positive or negative direction; With D1 and D2 the distances estimated by the first sonar and the second sonar respectively, and d the distance between the two sonars (see figure 2), the yaw angle A is given by the following trigonometric calculation: A = arctan((D2 - D1) / d).

[0108] 2. The second measurement, differential, is the difference in distance measured by the first sonar 110 and by the second sonar 120. This difference is a good substitute function for estimating the "state" of the drone. Just as for the exact calculation of the yaw angle, if this difference is equal to zero, the drone is correctly positioned relative to the surface 200. A negative or positive difference induces a significant instruction to reposition the drone. The difference in distance is given simply by D2 - D1.

[0109] A set of at least a third sonar can also be planned.

[0110] In this case, a set of four sonars can be provided, in which the first sonar 110 and the second sonar 120 are identical, having identical detection cones. The first sonar 110 and the second sonar 120 make it possible to determine not only the distance between the drone 100 and the surface 200 but also the angle between the drone 100 and the surface 200, i.e. the yaw, using differential calculus.

[0111] A third sonar, whose detection range is greater than that of the first sonar 110 and the second sonar 120, makes it possible to detect whether the drone 100 is at a long distance from the surface 200, i.e. beyond a predetermined threshold value.

[0112] A fourth sonar, whose detection range is less than that of the first sonar 110 and the second sonar 120, makes it possible to detect whether the drone 100 is at a short distance from the surface 200, i.e. below a predetermined threshold value; which makes it possible to implement emergency detection if the drone 100 is too close to the surface 200, i.e. the distance between the drone 100 and the surface 200 presents a danger.

[0113] It is also possible to provide a set of at least one stereo camera, the detection distance of which is greater than the detection distance of the first sonar 110, the second sonar 120 or the third sonar.

[0114] It is also possible to provide at least one 360 ​​lidar, the detection distance of which is greater than the detection distance of the stereo camera.

[0115] It is thus possible to obtain a succession of distance detection ranges, one range per type of sensor. In operation, in one embodiment, as long as the sonars do not return any value (the sonars have a detection capacity of the order of a meter), then the position of the drone 100, or more precisely the distance between the drone 100 and the surface 200 is determined by the minimum of the value of the other sensors (lidar and stereo camera). As soon as the sonars are active, then the value of the sonars replaces that of the other sensors (lidar and stereo camera), the values ​​of the lidar and stereo camera being able to be ignored.

[0116] At a distance of 1m, the first and second 120 sonars take over from the stereo camera, as they are more precise and less subject to noise.

[0117] With four sonars, we advantageously have operation by 2 pairs of sonars:

[0118] - a first pair of sonars, with the first and second sonars 120, where the sensors are identical to each other, and which makes it possible to manage the yaw of the drone 100 relative to the surface 200, considered to be locally flat; and

[0119] - a second pair of sonars, with the third and fourth sonars where the sensors are different from each other, and which makes it possible to manage the distance to the surface 200, so that the drone 100 is “neither too close nor too far”, within a predetermined distance range.

[0120] The distance from each sensor (sonar) to the surface 200 is determined by the value of each sensor, in particular the sonars. Thus the distance D from the drone 100 to the surface 200 is determined.

[0121] Similarly, by differential calculation of the measurements of the first sonar 110 and the second sonar 120, it is possible to detect the yaw angle of the drone 100 relative to a normal to the surface 200.

[0122] The position of the drone 100 relative to the surface 200, in particular the distance, i.e. the position in X, can then be controlled by a predetermined distance instruction.

[0123] The position of the drone 100 relative to the surface 200 can also be controlled by the yaw angle of the drone 100 which is detected using the measurements of the first sonar 110 and the second sonar 120, with reference to a predetermined yaw angle setpoint of the drone 100. Whatever the distance sensors, it is also advantageous to produce a depth map using the measurements of the assembly of at least one distance sensor, in particular a stereo camera.

[0124] Advantageously according to the invention, defects on the surface 200 can be detected using the measurements of the assembly of at least one distance sensor, in particular using the sonars, and more particularly using the fourth sonar.

[0125] The stereo camera can work simultaneously with the sonars. Preferably, the sonar values ​​take precedence over those of the stereo camera, because the values ​​measured by the sonars have a lower variance than the values ​​of the stereo camera.

[0126] Typically, the stereo camera is reliable up to 3m away from the surface 200. The stereo camera is therefore optional.

[0127] Thus, the environment in which the drone 100 operates can be segmented according to 3 distance sensors:

[0128] - sonars, which enable the management of the near-surface environment 200;

[0129] - the stereo camera for an environment 4m from the surface 200, with a wider angle than that of the sonars;

[0130] - a 360 LIDAR, for an even wider understanding of the environment, beyond 4m, or for a 200 surface or complex facade (e.g. balcony).

[0131] Advantageously according to the invention, it is not necessary to carry out mapping prior to flight.

[0132] Obviously, a treatment fluid can be sprayed, preferably under high pressure, onto said surface 200.

[0133] The activation of the treatment fluid projection system is preferably controlled by the position of the drone 100 relative to the surface 200. Preferably, the treatment fluid projection system is activated only when the distance D from the drone 100 to the surface 200 is equal to the distance setpoint.

[0134] For example, for high-pressure cleaning, the high-pressure cleaning nozzle is approximately 5 cm from the surface 200 to be cleaned and the body of the drone 100 is approximately 1 m from it. For spraying cleaning products, the spray nozzle is, for example, approximately 40 cm from the surface 200 to be maintained. Thanks to the invention, the position accuracy is approximately 5 cm over a nozzle position range of between 5 cm and 90 cm from the surface 200.

[0135] By "approximately" we mean, with a margin of plus or minus 10%.

Claims

Claims 1. Wired drone (100) for treating a surface (200) by spraying a treatment fluid, the drone (100) comprising: - a propulsion system, comprising a set of engines, front propellers and rear propellers, - a treatment fluid projection system comprising a set of at least one spray nozzle for spraying, preferably under high pressure, said treatment fluid, said set comprising a solenoid valve and being connected to a sealed sheath for supplying treatment fluid, - a set of at least one distance sensor, wherein the set of at least one distance sensor comprises: - a first sonar (110), configured to measure the distance between said first sonar (110) and said surface (200), - a second sonar (120), preferably identical to the first sonar (110), oriented in the same direction as the first sonar (110) and configured to measure the distance between said second sonar (120) and said surface (200), the drone (100) further comprising: - a computing unit, configured for: • measuring the distance between said first sonar (110) and said surface (200); • measuring the distance between said second sonar (120) and said surface (200); • calculate a differential measurement between the measurement of the first sonar (110) and the measurement of the second sonar (120); deduce from this: - the yaw angle of the drone (100) relative to a normal to the surface (200), and - the distance from the drone (100) to the surface (200); • and control the position of the drone (100) relative to the surface (200) by difference between: - the calculated distance and a predetermined distance instruction, and - the calculated yaw angle of the drone (100) and a predetermined yaw angle setpoint of the drone (100); characterized in that the drone (100) comprises an autopilot system comprising a general servo device which comprises a first PID regulator and which allows servo control in roll, yaw and pitch, and in which the calculation unit, which comprises a second PID regulator distinct from the first PID regulator, is configured to servo control the position of the drone (100) relative to the surface (200) by difference between: • the calculated distance and a predetermined distance instruction, and • the calculated drone yaw angle (100) and a drone yaw angle setpoint (100).

2. Drone (100) according to claim 1, wherein the calculation unit is configured to control the position of the drone (100) relative to said surface (200) so that the difference between the calculated yaw angle of the drone (100) and the yaw angle setpoint is equal to 0.

3. Drone (100) according to any one of the preceding claims, wherein the first sonar (110) and second sonar (120) are symmetrical to each other with respect to a longitudinal plane of symmetry.

4. Drone (100) according to any one of the preceding claims, in which the activation of the treatment fluid projection system is controlled by the position of the drone (100) relative to the surface (200).

5. Drone (100) according to any one of the preceding claims, wherein the set of at least one distance sensor further comprises at least one of the following sensors: • a set of at least one third sonar; • a set of at least one stereo camera, the detection distance of which is greater than the detection distance of the first sonar (110), the second sonar (120) or the third sonar.

6. Drone (100) according to claim 5, wherein the set of at least one distance sensor further comprises at least one lidar (360), the detection distance of which is greater than the detection distance of the stereo camera.

7. Drone (100) according to any one of the preceding claims, further comprising automatic piloting means, so that the drone (100) is autonomous or semi-autonomous.

8. Drone (100) according to any one of the preceding claims, wherein the accuracy of the position of the drone (100) relative to said surface (200) is 5 cm + / - 10% over a position range of the assembly of at least one spray nozzle between 5 cm and 90 cm from said surface (200).

9. Method for treating a surface (200) with a treatment fluid, using a wired drone (100) according to any one of the preceding claims, the method comprising steps consisting of: - detecting the distance from the drone (100) to said surface (200), - detect the yaw angle of the drone (100) relative to a normal to the surface (200), - control the position of the drone (100) relative to the surface (200) by difference between: • the detected distance and a predetermined distance setpoint, and • the detected yaw angle of the drone (100) and a predetermined yaw angle setpoint of the drone (100), the method further comprising at least one of the steps consisting of: - create a depth map using measurements from at least one distance sensor, - detecting defects on said surface (200) using measurements from the assembly of at least one distance sensor, and - spraying, preferably under high pressure, a treatment fluid onto said surface (200).

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