ES2823073B2 - LANDING GEAR ATTACHABLE TO A DRONE STRUCTURE - Google Patents

Description

LANDING GEAR ATTACHABLE TO A DRONE STRUCTURE

OBJECT OF THE INVENTION.

The invention falls within the technical framework of unmanned aerial systems and the inspection of industrial pipes.

The present invention relates to a landing gear that can be attached to a VTOL unmanned aerial system to provide it with the ability to land and move over and along pipes of different diameters and materials.

An object of the present invention is to provide a landing gear that allows an aerial vehicle to position sensors at different points on the external surface of pipes to carry out inspection tasks.

BACKGROUND OF THE INVENTION

Industrial pipes suffer degradation processes in the form of material loss and pitting due to erosion, cavitation, corrosion and fatigue. There are non-destructive inspection methods that allow the thickness of the duct walls to be measured, with ultrasound (UT) inspection being of special interest due to its precision and immediacy. With this technique, a piezoelectric probe or an EMAT probe must be positioned directly on the internal or external surface of the point of the wall to be inspected.

Currently, for the positioning of sensors in inspection tasks, specialized robots are used, due to the many advantages they have over manual access: speed and access capacity, flexibility, precision, safety and economy.

The greatest development has been in robots for internal inspection of pipes. In fact, the most widespread inspection method is intelligent pigging inspection, which makes use of sensor-laden devices that navigate inside the ducts dragged by the pipeline fluid itself.

For pipes where inspection by scraping is not feasible due to its limitations, a wide variety of robots have been developed with different locomotion systems: tractor wheels, caterpillars, gas ejection, or by means of anchoring and pushing mechanisms (imitating the movement of a worm). Numerous commercial solutions are found and actively applied. The Pipetel Explorer uses drive wheels pressed against the pipe wall. Diakont's Rodis has three tracks that rest on three different points on the inner circumference of the pipe. The Balboa Viper is powered by compressed air or nitrogen.

However, there are certain drawbacks. In cable-operated robots it is necessary to empty the pipe and the scope is limited by the length of the cord. Those that operate without cable, need special launch and collection points, do not provide data in real time and risk being trapped.

In refineries and nuclear plants, the use of external inspection robots is of interest, since they do not suffer from the aforementioned problems. Currently, there are two main types of robots developed for external inspection. There are commercial solutions, such as Silverwing's Scorpion 2, that use magnetic wheels or tracks to move across the surface of pipes. They are capable of moving horizontally, vertically, and around curves, but are generally unable to overcome obstacles and are limited to metal pipes.

The main alternative locomotion system consists of an annular structure equipped with wheels or traction chains that obtain their adherence from the pressure exerted by the ring when it closes around the wall of the duct. The Crawler from IMG Ultrasuoni or the Versatrax Microclimber from Inuktun are examples. They are usually limited to straight sections.

Aerial robots or drones have advantages in terms of accessibility and speed for pipe inspection. Drones equipped with sensors have been used for leak detection and inspection of pipelines in gas and oil pipelines and also for inspection of pipelines in industrial plants, where inspection is always done remotely using cameras.

To measure the thickness of the pipes to prevent leaks, these drones must have the ability to perform contact inspection using ultrasound, and for this it is necessary for the drone to land, fixate and move over the pipe. There are some devices that allow the landing gear of a drone to be adapted to irregular terrain so as not to overturn on landing, but they do not allow a VTOL drone to be deployed on a pipe.

WO2019144227 discloses a pipe tracker apparatus including one or more drive wheels capable of moving along and around a pipe, and one or more instruments coupled to the drive wheels. The instruments include sensing instruments and maintenance instruments. The pipe tracker includes a retention mechanism that holds the drive wheels against the outer surface of the pipe. The retention mechanism provides adjustable positions for the drive wheels. The apparatus includes a controller to move the drive wheels and operate the instruments. However, the apparatus is complex and expensive because the movement on the pipe is based on a drive wheel mechanism that is difficult to adapt to the pipes and their irregularities. In addition, it is not possible to use it as a drone landing gear.

Document RU2707644, published after the application date of the present invention, discloses a robot for the automatic and automated diagnosis of objects such as gas and oil pipelines. The robot has a mobile main platform with side wheels connected via a controller to activate a drive with drive wheels. It also comprises a video camera, a lighting unit, a gas detector and a universal robot control panel. In addition, the robot is equipped with an aerodynamic platform with support wheels and a propeller with horizontal stabilization on the left and one on the right, as well as a propeller controller. The use of lateral drive wheels makes the system complex and makes it difficult to implement it in guiding the robot on the pipe.

Document CN110614623, published after the application date of the present invention, discloses a self-adaptive variable radius pipe detection robot comprising a drive mechanism, a main frame, a damping mechanism, a detection system and a control system. The drive mechanism uses four off-axis motors to independently drive four wheels. Through differential movements it allows movements rotation and the like, and patrols in all directions of a pipeline. The damping mechanism is equipped with a spring damper, to allow the robot to continue when it encounters a bump due to a pipe connection, straddling the bump to cross it. The robot then recovers its original size under the action of the spring to continue moving forward. This robot allows automatic adjustment according to the radius of the outer surface of the pipe, without the need for an external power source and reducing the complexity of the structure. This solution is also complex and expensive due to its spring damping mechanism and the implementation of traction in said mechanism, which allows it to adapt to irregularities but complicates its use and maintenance. In addition, it is not possible to use it as a drone landing gear.

DESCRIPTION OF THE INVENTION

The present invention describes a landing gear capable of deploying on the external surface of industrial pipes of various sizes and materials, a VTOL drone equipped with sensors intended to carry out inspection tasks at points that are not accessible by usual external inspection robots. .

Specifically, the landing gear is designed to carry out external ultrasonic inspection of industrial pipes using a VTOL drone equipped with sensors, which can be of the EMAT type, so that the drone is positioned above the pipe to be inspected.

Unlike ring-based external inspection systems, this landing gear is coupled to a drone capable of flying to pipe points that external inspection robots cannot access due to the presence of obstacles along the way. The pipe. The fixing system of the landing gear of the invention, in the form of a clip, unlike the ring, can be opened and closed allowing remote coupling and uncoupling.

The landing gear is therefore intended to be coupled to the structure of a VTOL (vertical take-off and landing) drone and comprises elements that are coupled to a lower surface of a VTOL drone, in particular, at least two clamp mechanisms, preferably, one located in a front area and another in a rear area, and a steerable tractor wheel mechanism located in the central area of the bottom surface of the drone.

The clip mechanism comprises a drone coupling structure, to be coupled to the lower surface of the drone, a central body; two side arms, which are preferably L-shaped, and a first actuator that drives the movement of the arms.

The central body connects to the drone's docking structure and houses the first actuator. The lateral arms comprise an internal face and an internal end, and are attached to the body of the clamp, so that they can pivot around said internal end. In this way, the first actuator can drive the movement of the arms, causing them to pivot around their inner end, resulting in an opening and closing movement of the clamp.

The arms also comprise omnidirectional wheels that are coupled to the inner face of said arms, so that once the gripper mechanism is coupled to a pipe, the omnidirectional wheels are in contact with said pipe.

The arms can pivot around their inner end by making use of a pair of lateral rods, which comprise the central body. For this, the arms can have through holes at their inner end, so that the lateral rods pass through said through holes.

Preferably, the gripper mechanisms comprise a train of gears, to allow movement of the arms. The gear train in turn can comprise a first and a second gear at its output that rotate at the same speed and in opposite directions in order to allow the clamp to close. Likewise, the arms may have at their inner end a semicircular rack concentric to the through hole, to engage in the gear train of the caliper body.

On the other hand, the central body is preferably formed by two complementary panels separated by tubular spacers, so as to guarantee the ideal separation between the complementary panels to allow the rotation of the arms.

On the inner wall of each arm, the omnidirectional wheels can be attached by means of a second articulated suspension. These omnidirectional wheels are the element that contacts the external wall of the pipe when the clamp closes around it, allowing movement without slipping in the longitudinal direction of the pipe and in the circumferential direction.

The second articulated suspension preferably comprises a first wishbone, a second wishbone and a second shock absorber. Thus, the first fork and the second fork are joined to each other and to the omnidirectional wheel by their open part, making use of a through axle for the omnidirectional wheel.

For its part, the second shock absorber comprises two rods, a first rod and a second rod, so that the first rod is attached to the inner face of the arm.

The closed part of the first fork joins the inner face of the arm and the closed part of the second fork joins the second stem of the second shock absorber.

The steerable tractor wheel mechanism comprises a fixed platform that is attached to the bottom surface of the drone, a mobile platform, which rotates with respect to the fixed platform by means of a second actuator, a tractor wheel, attached to the mobile platform and a third actuator, which drives the movement of the drive wheel.

The fixed platform preferably comprises a circular hole inside, the inner wall of which has a circular rack and, on its upper edge, has a bevel that can house a set of bearing balls.

The mobile platform, for its part, can be formed by an upper panel and a lower panel, preferably circular, which are closed by pressure on the upper and lower part of the central hole of the fixed platform and rest on the bearing balls to rotate around. to the vertical axis with respect to the fixed platform.

The second actuator is attached to the mobile platform and comprises a central pinion that meshes with the circular rack of the fixed platform, allowing the orientation of the mobile platform to be controlled.

The drive wheel is attached to the mobile platform by means of a first articulated suspension that houses the third actuator and may comprise a rigid panel, a second support and a first shock absorber, which comprises two rods.

The rigid panel is connected with the lower panel of the mobile platform, by means of a first support, with a first rod of the shock absorber and with the support.

The bracket connects to the bottom of the rigid panel and is attached to a second shock absorber rod and the drive wheel. In addition, the support houses the third actuator, which is connected laterally to said support and to the drive wheel, to produce its movement.

The first articulated drive wheel suspension is dimensioned so that when the drone's clamp mechanisms close around the pipe, the drive wheel is pressed against the outer wall of the pipe, generating traction when driven by its third actuator. .

The mobile platform allows to orient the tractor wheel in the longitudinal or transversal direction of the tube. With the drive wheel oriented in the transverse direction, the traction helps to stabilize the roll of the VTOL drone. With the drive wheel oriented in the longitudinal length, the drive moves the drone along the pipe. In forward motion, the roll of the drone is exclusively stabilized by the VTOL drone propulsion system.

In the case of an inspection operation by means of a VTOL drone under the remote control of a pilot, the pilot's transmitter and the drone's reception system have four additional channels to control the actuators of the gripper and tractor wheel mechanisms. The clamp mechanisms and the tractor wheel mechanism are attached to the bottom surface of the drone and the actuators are connected to their respective channels on the drone's receiver.

The operation begins with the drone on the ground, supported on the tips of the arms, with the clamp mechanisms in an open position, and with the drive wheel oriented in the direction perpendicular to the drone's forward direction. The pilot takes off and positions the drone vertically at a point on the pipeline close to the inspection point. The pilot directs a low speed vertical descent until the drive gear drive wheel The landing makes contact with the pipe, at which point the first actuator is actuated to cause the clamp mechanisms to close.

By controlling the third actuator, which controls the drive wheel oriented in the transverse direction of the tube, and the drone's propulsion system, the pilot can maintain the drone's roll stabilized while it is fixed to take measurements with the sensors with which it is equipped. .

In order to move the drone over the pipe to another point, the pilot commands the second actuator, which controls the rotation of the mobile platform of the drive wheel mechanism, aligning it with the longitudinal direction of the drone and then commands the third actuator, which controls the drive wheel, to generate traction in the desired direction. Once the drone reaches the new point, the second actuator is commanded to align the wheel with the cross direction of the tube.

Once the operation is finished, the pilot commands the first actuator to allow the opening of the clamps, it separates from the pipe through a vertical takeoff and drives the drone to the landing point, landing with the clamp mechanisms in an open position.

DESCRIPTION OF THE DRAWINGS

Fig. 1.- perspective view of a preferred embodiment of the invention comprising two gripper mechanisms and a drive wheel mechanism.

Fig. 2.- Bottom view of the preferred embodiment of the invention shown in Figure 1.

Fig. 3.- Exploded perspective view of the central body with the assembled arms and the first actuator.

Fig. 4.- Exploded perspective view of the central body and the first actuator.

Fig. 5.- Front view of one of the arms of the clamp mechanism, with the omnidirectional wheels mounted.

Fig. 6.- Exploded perspective view of an omnidirectional wheel.

Fig. 7.- Exploded perspective view of the clamp body, showing the assembly of the arms.

Fig. 8.- Front view of the central body with the arms assembled.

Fig. 9.- Perspective view of the assembly of the central body to the coupling structure and from this to the lower surface of the drone.

Fig. 10.- Perspective view of the drive wheel mechanism.

Fig. 11.- Perspective view of the drive wheel mechanism including part of the suspension structure.

Fig. 12.- Exploded perspective view of the first articulated suspension, the third actuator and the drive wheel.

Fig. 13.- Front view of the landing gear attached to a drone, coupled to a conduit, with the clamps closed around it and with the drive wheel resting on the outer wall.

Fig. 14.- Side view of the landing gear attached to a drone, shown in Figure 13.

PREFERRED EMBODIMENT OF THE INVENTION

The invention refers to a landing gear intended to be coupled to a VTOL drone, for vertical landing and takeoff. The landing gear of the invention allows the drone, to which it is intended to be coupled, to land on a pipe for ultrasonic inspection, remain attached to said pipe and move along it.

Figure 1 shows a preferred embodiment of the landing gear of the invention. The landing gear comprises two clamp mechanisms (1) and a drive wheel mechanism (2). Both mechanisms (1, 2) are adapted to be coupled to a lower surface of the drone (3).

Each clamp mechanism (1) comprises a coupling structure (4) to the drone, which is in the form of a lattice, attachable to the lower surface of the drone (3), in particular, the clamp mechanisms (1) are intended to be coupled in a front area and in a rear area, respectively, of said lower surface of the drone (3).

Each clamp mechanism (1) also comprises a central body (5) and two arms (6), designed to pivot around said central body (5). The arms (6) of the clamp mechanism (1) are L-shaped to allow them to surround a pipe when the clamp mechanism (1) is closed. Each of the arms (6) comprises, in turn, two omnidirectional wheels (7) joined to the arms (6) at two points.

In addition, the clamp mechanism (1) comprises a first actuator (9) coupled to the central body (5) and mechanically connected to the arms (6) in order to produce their rotational movement around the central body (5). ).

Figure 2 shows another view of the landing gear of the invention. The drive wheel mechanism (2) of the landing gear shown in Figure 2 comprises a fixed platform (10), attachable to the lower surface of the drone (3), in particular, in a central area of said lower surface of the drone ( 3), a mobile platform (11) configured to rotate with respect to the fixed platform (10), a first articulated suspension (14), incorporating a first shock absorber (49), a drive wheel (13), attached to the platform mobile (11) by means of the first articulated suspension (14), a second actuator (12) connected to the mobile platform (11) to cause a rotational movement of said mobile platform (11), and a third actuator (15) housed in the first suspension (14) and connected to the drive wheel (13) to cause its movement.

Figure 3 shows a detail of the assembly of the lateral arms (6) in the central body (5). Said central body (5) comprises two complementary panels (18, 35) separated by a set of tubular spacers (36) that ensure that the distance between both complementary panels (18, 35) is the desired one.

Between the complementary panels (18, 35) there is a gear train (24) coupled to a first complementary panel (18). The first complementary panel (18) also supports the first actuator (9), an adapter (19) being arranged between both elements. The gear train (24) located between the complementary panels (18, 35) is mechanically connected with the lateral arms (6), so that the movement of said gear train (24) causes the movement of the lateral arms (6), producing the opening or closing of the clamp mechanism ( one).

The lateral arms (6), shown in figure 3, also comprise an inner end, which is the one that joins the central body (5), and an inner face, the surface located in the closing direction of the clamp mechanism. (1), to which two omnidirectional wheels (7) are attached on each arm (6), so that when the clamp mechanism (1) closes around a pipe, the omnidirectional wheels (7) are in contact with that pipe. The omnidirectional wheels (7) are attached to the inner face of the lateral arms (6) by means of a second articulated suspension (8).

Figure 4 shows a detailed view of the first complementary panel (18) of the central body (5), the gear train (24) and the first actuator (9). Thus, the first complementary panel (18) of the central body (5) comprises a central rod (23), which supports a first gear (26) of the gear train (24), and two other lateral rods (22), which support each of the lateral arms (6) respectively. The gear train (24), in this case, is formed by the first gear (26) and a second gear (25), which rotate at the same speed, but in opposite directions to engage in the lateral arms (6) and produce in them a rotational opening or closing movement of the clamp mechanism (1). The adapter (19) is a surface that mechanically connects the first actuator (9) with the first complementary panel (18) of the central body (5) and comprises a central slot (21) that allows the connection between the first actuator (9) and the gear train (24) located between the two complementary panels (18, 35). Likewise, the first complementary panel (18) also comprises a coupling slot (20) that allows the connection between the first actuator (9) and the gear train (24).

Figure 5 shows a detail of a lateral arm (6), incorporating omnidirectional wheels (7). The lateral arm (6) comprises a through hole (27) at its inner end, which allows connection to the central body (5), and a semicircular rack (28), which meshes with the gear train (24) located in inside said central body (5). In addition, each of the omnidirectional wheels (7) is attached to the lateral arm (6) by means of two holes (29, 30), located in the vicinity of the internal face, to which they are connected by means of the second suspension (8) articulated.

Figure 6 shows a specific detail of the assembly of the omnidirectional wheels (7) and the second articulated suspension (8). Said second articulated suspension (8) is formed by two rigid forks (31, 32), which have an open end and a closed end, a through axle (34) and a second shock absorber (33) with two rods. Thus, both rigid forks (31,32) are placed with the open end aligned with an axis of rotation of the omnidirectional wheel (7), so that a first fork (31) comes into contact with the omnidirectional wheel (7), while a second fork (32) rests on the first fork (31). Next, the thru-axle (34) joins the two forks to the omni-directional wheel (7), so that it allows the rotation of the omni-directional wheel (7) around the thru-axle (34), and the relative movement of the first fork (31) and the second fork (32) with respect to the omnidirectional wheel (7) and with each other.

The first fork (31) is attached to a first hole (29) of the two holes (29, 30), located in the vicinity of the internal face, being able to rotate around said first hole (29), while the second fork (32) is attached to a first stem of the two stems of the second shock absorber (33), being able to rotate around said first stem, and a second stem of the second shock absorber (33) is attached to a second hole (30) of the internal face of the arm (6), being able to rotate around said second hole (30).

Figures 7 and 8 show two views of the assembly of the first complementary panel (18) of the central body (5) and the lateral arms (6). The lateral rods (22) are inserted through the through holes (27) at the internal end of the arms (6), at the same time that the first gear (26) and the second gear (25) of the gear train (24) mesh with the semicircular rack (28) of the arms (6). Thus, the arms (6), driven by the semicircular rack (28) geared to the gear train (24) that drives the first actuator (9), pivot around the lateral rods (22) of the central body (5), producing an opening or closing movement of the clamp mechanism (1).

Figure 9 shows an assembly view of the assembly formed by the central body (5) and the lateral arms (6), and the lower surface of the drone (3). The connection is made by means of the coupling structure (4), which comprises a first set of connection holes (38) in its lower area to join, by means of a screwed joint, said coupling structure (4) to the central body ( 5), which in turn comprises a set of complementary holes (39) in its upper area. Also, the structure The coupling structure (4) also comprises a second set of connection holes (37) in its upper area to join, by means of a screwed joint, said coupling structure (4) to the lower surface of the drone (3), which, in turn, time, it comprises a first set of coupling holes (16) to allow said union.

Figure 10 shows a view of the drive wheel mechanism (2), where it can be seen that the fixed platform (10) comprises an interior central hole and the mobile platform (11) is located inside said central hole. In addition, the fixed platform (10) comprises a set of perforated flanges (40) to allow the attachment of said fixed platform (10) to the lower surface of the drone (3), which also comprises a second set of coupling holes (17). ). The first articulated suspension (14) connects the mobile platform (11) to the drive wheel (13) and supports the second actuator (12) and the third actuator (15).

Figure 11 shows an exploded view of the drive wheel mechanism (2), which includes the fixed platform (10), the mobile platform (11), the first articulated suspension (14) and the second actuator (12). In the inner central hole of the fixed platform (10) there is a circular rack (44) and a bevel (43), located on the upper edge of the inner central hole, intended to house a set of bearing balls.

The mobile platform (11) is made up of two circular panels, an upper panel (41) and a lower panel (42), connected by a bolted joint. The upper panel (41) rests on the bearing balls located on the bevel (43) of the fixed platform (10), while the lower panel (42) is placed under said bearing balls.

Furthermore, the second actuator (12) of the drive wheel mechanism (2) also comprises a central pinion (45) engaged in the circular rack (44) of the fixed platform (10). The second actuator (12) is attached to a first support (46) which in turn is connected to the lower panel (42) of the mobile platform (11), by means of a bolted joint.

Thus, the combination of the fixed platform (10), the mobile platform (11) and the second actuator (12) allows a rotation movement of the drive wheel mechanism (2), by sliding the upper panel (41) and the lower panel. (42) of the mobile platform (11) on the bearing balls by the action of the central pinion (45) of the second actuator (12).

The first support (46), shown in figure 11, joins with the lower panel (42) of the mobile platform (11), with the second actuator (12) and with the first articulated suspension (14), which comprises a rigid panel (47) through which it joins the first support (46).

Figure 12 shows an exploded view of the first articulated suspension (14), the drive wheel (13) and the third actuator (15). The first articulated suspension (14) comprises the rigid panel (47), the first shock absorber (49), with two rods, and a second support (48), which includes a central hole. The rigid panel (47) joins with a first rod of the first shock absorber (49), in its upper zone, and with the second support (48), in its lower zone. A second rod of the first shock absorber (49) connects with the second support (48).

The drive wheel (13) is attached to the support by means of an axis that passes through the support through a perforation (51) of the same, the wheel through its axis of rotation and connects with the third actuator (15), passing through the support once more through a hole (50) to which said third actuator (15) is coupled.

Figures 13 and 14 show two views of the landing gear of the invention mounted on a VTOL drone and coupled to a pipe by means of the clamp mechanism (1), where the lateral arms (6) surround the pipe and put the wheels in contact. omnidirectional (7) with said pipe, likewise, the drive wheel (13) also comes into contact with the pipe, to generate traction against the wall. If the drive wheel (13) is oriented longitudinally, the traction is used to perform a forward or backward movement along the pipe. If the drive wheel (13) is oriented transversely, the traction is used to cooperate with the drone's propulsion system in stabilizing its balance around the pipe.

Claims (14)

1. Landing gear attachable to a structure of a vertical takeoff and landing VTOL drone, comprising a lower surface of the drone (3), and in which the landing gear comprises: • at least two clip mechanisms (1), attachable to the lower surface of the drone (3), each comprising: or a coupling structure (4) to the drone, intended to be coupled to the lower surface of the drone (3); or a central body (5), mechanically connected to the coupling structure (4); or two lateral arms (6), each comprising an internal face and an internal end, joined to the central body (5), so that the arms (6) can pivot around their internal end, and comprise omnidirectional wheels (7 ), coupled to its inner face; characterized in that each clamp mechanism (1) comprises a first actuator (9), housed in the central body (5), connected to the arms (6) to drive its movement; and because the landing gear also comprises: • a steerable drive wheel mechanism (2), attachable to a central area of the lower surface of the drone (3), comprising: or a fixed platform (10) attachable to the structure of the drone (3); or a mobile platform (11), linked to a second actuator (12), and which rotates with respect to the fixed platform (10) around the vertical axis by means of said second actuator (12); or a tractor wheel (13), connected to the mobile platform (11) by means of a first articulated suspension (14); or a third actuator (15) housed in the first suspension (14), connected to the drive wheel (13) to drive its movement. 2. Landing gear according to claim 1, wherein the arms (6) are L-shaped. 3. Landing gear according to claim 1, wherein the clamp mechanisms (1) are attachable to the lower surface of the drone (3), in a front area and a rear area. 4. Landing gear according to claim 1, wherein the central body (5) comprises a first complementary panel (18) and a second complementary panel (35), separated by tubular spacers (36). 5. Landing gear according to claim 4, wherein the central body (5) comprises two lateral rods (22) joined to the first complementary panel (18), so that the arms (6) have, at their inner end, through holes (27) that allow said rods (22) to pass through them, to allow the closing of the clamp mechanism (U 6. Landing gear according to claim 1, where the central body (5) also comprises a gear train (24), driven by the first actuator (9), which drives the movement of the arms (6). Train according to claim 6, characterized in that each arm (6) has, at its inner end, a semicircular rack (28), which meshes with the gear train (24) contained in the central body (5). 8. Landing gear according to claim 7, wherein the gear train (24) comprises a first gear (26) and a second gear (25) that rotate at the same speed and in opposite directions, so that each of the gears (25, 26) mesh with the rack (28) of one of the arms (6). 9. Landing gear according to claim 1, where the omnidirectional wheels (7) are coupled to the inner face of the arms (6) by means of a second articulated suspension (8). 10. Landing gear according to claim 9, wherein the second articulated suspension (8) comprises: - a first fork (31) and a second fork (32), which have an open part and a closed part, which are joined to each other and to the omnidirectional wheel (7) by its open part by means of a through axle (34), and - a second shock absorber (33), comprising two rods, a first rod attached to the inner face of the arm, and where the first fork (31) joins the inner face of the arm at its closed part and the second fork (32) joins at its closed part a second stem of the second shock absorber (33). 11. Landing gear according to claim 1, wherein the fixed platform (10) of the drive wheel mechanism (2) comprises a central circular hole, which has a bevel (43) on its upper edge, intended to house a set bearing balls, and a circular rack (44) on the inner wall. 12. Landing gear according to claim 11, wherein the second actuator (12) of the drive wheel mechanism (2) also comprises a central pinion (45), which engages on the circular rack (44) of the fixed platform ( 10). 13. Landing gear according to claim 11, wherein the mobile platform (11) comprises an upper panel (41) and a lower panel (42), so that the upper panel (41) is placed on the bezel (43). ) of the fixed platform (10), resting on the bearing balls housed in said bevel (43), to pivot around the vertical axis, and the lower panel (42) is placed under said bearing balls. 14. Landing gear according to claim 13, wherein the first suspension (14) of the drive wheel mechanism (2) comprises: - a rigid panel (47), joined to the lower panel (42) of the mobile platform (11) by means of a first support (46), - a first shock absorber (49), comprising two rods, where a first rod is attached to the rigid panel (47), and - a second support (48), attached to the lower area of the rigid panel (47) and to a second rod of the first shock absorber (49), where the drive wheel (13) is connected to the second support (48) and the third actuator (15).