EP3927437A1

EP3927437A1 - Belay device for assisted climbing

Info

Publication number: EP3927437A1
Application number: EP20710236.9A
Authority: EP
Inventors: Jérôme BOURQUARD
Original assignee: Abeo SA
Current assignee: Abeo SA
Priority date: 2019-02-19
Filing date: 2020-02-18
Publication date: 2021-12-29
Also published as: WO2020169914A1; FR3092766A1; CN113423472A; FR3092766B1; US20220134164A1

Abstract

The invention relates to a belay device for climbing comprising an automatic winder (1) comprising a pulley (10) and a rope (3). The device comprises an electric motor (12) configured so as to apply a torque to the pulley (10) and an encoder coupled to the pulley. The motor is controlled using the encoder according to the rotation of the pulley (10) so as to modulate said torque applied to the pulley according to at least: - an assistance mode in which the torque applied by the servomotor to the pulley (10) drives a pulling of the rope (3) which assists the climber in his climb; and - a fall mode in which the torque applied by the servomotor to the pulley (10) blocks a fall of the climber or slows it to a speed less than 3 m/s. The invention also relates to a climbing game system with virtual or augmented reality using such a belaying device.

Description

Belay device for assisted climbing

The present invention relates to the field of climbing as a sport or leisure physical activity.

It relates in particular to a device of the belay brake type having increased functions compared to devices known in the state of the art.

The practice of climbing as a sport is currently developing among the general public. In order to practice this activity in complete safety, equipment allowing the climber to be secured in a simple and efficient manner has been developed.

In a known manner, it is common practice to secure a climber in rope climbing "in a pulley workshop" also called a "top rope" using a rope passing through a pulley installed at the top of the route or of the climbing block. One or two insurers are responsible for insuring the climber in the event of a fall or, if necessary, during his descent. The rope is introduced into a belay brake connected to a harness worn by the belayer. The belay brake allows the belayer to release slack when climbing and to brake or even block the rope in the event of a fall or descent of the climber.

Other known devices, called automatic reels, allow the belay of a climber. Very generally, automatic reels constitute so-called rope distribution means and serve to protect a climber against falls by retracting into the reel the play present in the rope when the rope is not under load and by providing a braking force when the rope is loaded, so that the weight at the end of the rope is reduced with a safe purpose (typically, to prevent or slow down a fall).

To provide the braking force, several systems such as a friction brake or a hydraulic damping mechanism have been used in the automatic reel type rope distribution devices. Furthermore, the known devices are distinguished by the presence or by the absence of a clutch to engage the braking system and conversely to disengage it when the rope is not under load, the devices employing a device which does not require clutch may prove to be safer.

For example, document US2014048639 discloses an automatic reel combining a rope return spring and a braking system contactless eddy current, operating on the principle that when an electrically conductive element passes through a magnetic field (or vice versa), the relative motion induces a flow of electric currents in the conductor, which in turn induce a magnetic field which opposes the magnetic field which is applied.

This type of device is simple, effective and safe. Nevertheless, in the context of the development of climbing as a physical activity accessible to many audiences, or as a fun leisure activity, the Applicant has discovered that it could be advantageous to propose an automatic belay device offering new functions. Thus, the invention relates to a belay device for climbing

comprising an automatic reel comprising a pulley and a rope. The device is configured so that the rope is wound or unwound according to the progress of a climber provided by said belay device. The belay device comprises an electric motor configured so as to be able to apply a torque to the pulley and an encoder coupled to the pulley, the motor being controlled by an electronic control circuit using the encoder as a function of the rotation of the pulley so as to modulate said torque applied to the pulley according to at least:

- an assistance mode in which the torque applied by the motor to the pulley pulls the rope which assists the climber in his climb; and - a fall mode in which the torque applied by the motor to the pulley blocks a fall by the climber or slows it down to maintain it at a speed less than 3 m / s.

The device thus proposed in the invention makes it possible to ensure a climber, while offering an assistance function. In particular, the device makes it possible to manage both the climb or "climb" of the climber, and his fall, using a simple and unique system based on a servo motor using an encoder capable of characterizing the rotation of the pulley. The servo-control of the motor is implemented in at least two modes depending on whether the climber is climbing or falling. The device makes it possible in particular to manage the climber's fall in a reliable manner, without resorting to a mechanical, electromagnetic or hydraulic clutch, as is the case in most known belay systems, and also offers an assistance function to the climbs. This opens the practice of sport climbing to a wide audience, or allows a fun practice of climbing. A simple device, based on a servo motor, which can correspond to a servomotor, is also particularly well suited to free climbing centers which are developing today. The motor can be slaved so that the torque driving the traction in the assistance mode is only applied when said encoder detects a rotation of the pulley which reflects a reduction in the force applied by the rope on the pulley.

A climbing aid is thus obtained, which is only active when the climber is actively climbing a wall or boulder. In other words, it is not a question of continuously and fixed reduction of the weight of the user during his ascent, but of proposing a device which adapts to the climb carried out, for example according to the efforts made. by the climber, or according to the dynamism of this climb.

Of course, permanent assistance is not excluded from the invention, and may be applied in some embodiments.

The value of the torque applied by the motor to the pulley in the assistance mode may in particular be a function of the value, rate, or speed of the decrease in the force applied by the rope on the pulley. It can be a function of a predefined device calibration value.

The motor can be servo-controlled so that, in the assist mode, the ascent speed, corresponding to the speed of the rope winding on the pulley, is substantially constant.

The device thus allows in particular an adaptation to the wishes or to the morphology, in particular to the weight, of the climber. The device can thus be adapted, for example, to a specific training program, for example providing for a climber's progression in his practice by reducing the level of assistance little by little. The device can be adapted to a more playful practice of climbing, by providing a very high level of assistance allowing the user to climb almost effortlessly, to jump from one grip to another, or even from a wall. to another, etc.

The motor can be servo-controlled so that in fall mode the torque applied to the pulley essentially ensures a predefined fall speed

substantially constant, regardless of the force applied by the rope (3) on the pulley.

The motor can be slaved so that in the fall mode the torque applied to the pulley allows the climber to gradually brake before ensuring a substantially constant fall speed.

The motor, as a controlled device, makes it possible to directly manage a climber's fall situation. In particular, the fall speed can be limited to a speed that avoids any risk of injury. It is accepted that a speed lower than 3 m / s, in particular a speed of about 2 m / s, is compatible with a safe descent. In addition, in certain embodiments of the invention, the servo-control of the motor can be programmed to ensure dynamic belaying of the climber, more comfortable and safer than sudden braking.

The motor can be directly linked to the pulley or can be linked via a synchronous mechanical transmission.

Thus, no clutch-type device is employed in the invention in its nominal mode of operation. A device of the clutch or mechanical brake type is only implemented, if necessary, in an optional degraded mode implemented for example in the event of a fault in the electrical supply to the device. The motor and the pulley are interconnected so that the motor causes a direct drive of the pulley, or with a gear ratio, in order to apply an assist or resistance torque.

The device may further include a disc brake configured to be actuated automatically in the event of an interruption of the power supply to said device.

By its configuration alone, the device can thus, in a degraded operating mode corresponding for example to an electrical power cut to the motor, ensure the safety of the climber in the event of a fall. The disc brake ensuring the safety of the climber in the event of a power failure to the device is engaged in the absence of power supply, and released when the device is powered on.

The motor may be of the brushless type and have a rotor carrying a series of permanent magnets and a stator carrying a set of windings.

Such an engine is reliable, little subject to wear, and allows to obtain a high mechanical torque.

The device may include a mechanical system allowing movement of the automatic reel, in a so-called transverse direction, perpendicular to the general direction of extension of the rope outside the automatic reel, this direction being said to be vertical. For example, the automatic reel is mounted on a rail extending in the transverse direction so that it can be freely translated along said rail, or on an arm pivoting along an axis extending substantially in the vertical direction.

A transverse movement of the automatic reel, which comprises in particular the pulley, makes it possible to follow the movement of the climber laterally. This increases user comfort, prevents movement of the climber's pendulum in the event of a fall, and makes the device compatible with wide climbing walls.

The invention also relates to a fun climbing system comprising a climbing structure, a virtual reality device such as a helmet or glasses, a computer system adapted to project into the virtual reality device an image applied to the structure to be climbed, and a belay device for climbing as described above.

The invention also relates to a fun climbing system comprising a climbing structure, an augmented reality device, a computer system adapted to project an image on the structure to be climbed, and a belay device for climbing such as: as previously described.

In a fun climbing system according to the invention, a sensor can be configured to determine the position and attitude of a climber using said fun climbing system, so as to vary the image projected in the device. virtual reality or on the structure to be climbed.

The device proposed in the invention allowing not only the belaying of a climber but also the climbing assistance makes it possible to envisage a playful use which differs from the current practice of climbing. By coupling the device to a virtual environment, whether it is generated using a virtual reality device or an augmented reality device, a unique experience can be offered to

the user. For example, a child or adult in this environment may feel like they are climbing a tree or building virtually recreated in correspondence with the holds available on a wall or other climbing structure. This fun activity is then carried out effortlessly, or even like a superhero, the belay device according to the invention being able to achieve performances inaccessible to a human. For example, it is possible to climb at high speed, perform jumps from holds to holds, or any other climbing experience with a reduced sensation of gravity.

Other features and advantages of the invention will appear further in the description below.

In the accompanying drawings, given by way of non-limiting examples: FIG. 1 shows, in a schematic three-dimensional view, a belay device in accordance with an embodiment of the invention;

FIG. 2 represents, in an exploded three-dimensional view, the device of FIG. 1; FIG. 3 represents, in a schematic view, a particular embodiment of the invention and its environment of use;

Figure 4 shows, in a three-dimensional schematic view, another embodiment of the particular invention and its environment of use;

FIG. 5 shows, in a three-dimensional schematic view, a fun climbing system according to an embodiment of another aspect of the invention.

Figure 1 shows an example of a belay device for climbing according to one embodiment of the invention. This device comprises an automatic winder 1, comprising a housing 2 inside which a rope 3, which may consist of a flat strap, is wound up and unwound as required.

The reel comprises a fixing interface 4, adapted to be fixed to a mounting bracket 5. In the example shown here, the device comprises the mounting bracket 5, which constitutes a fixed point capable of reliably supporting a force. important, greater than the weight of a climber.

The connection between the mounting bracket 5 and the attachment interface 4 of the reel 1 is made in the example shown using two bolts 6.

Other means of mechanical connection, for example tie rods or studs, are obviously possible. For example, the device may be without mounting bracket 5, so as to be fixed at the top of a climbing wall, for example using two carabiners.

In addition, as described in more detail with reference to Figures 3 and 4, the device can be configured to allow lateral movement of the reel, with a suitable mounting bracket that can have various configurations.

The device is provided with an electrical supply socket 7, allowing the connection of a supply cable 8. According to certain variants of the invention, the device can be equipped with a programming socket, which can be associated or disconnected from the power supply socket 7.

Figure 2 shows an exploded view of the belay device according to the embodiment shown in Figure 1, allowing in particular to see the internal elements of the housing 2 of the reel 1.

A frame 9, which in the example shown here comprises the fixing interface 4, constitutes the main structure of the belay device. A pulley 10 allows the winding and unwinding of the rope 3, which here takes the form of a flat strap. A rope guide 1 1 is used to guide the rope 3, in particular for its good winding on the pulley 10. The rope guide is typically a part, for example in plastic material, comprising a slot allowing the guided passage of the flat strap constituting the rope 3.

The device comprises an electric motor 12 which comprises a rotor 14 and a stator 13. The operation of the motor is controlled by an electronic control circuit 15.

The rotor 14 consists essentially of a ring on an internal face of which permanent magnets 16 are fixed. The permanent magnets 16 are advantageously powerful magnets, for example made of neodymium. The stator 13 is positioned inside the crown of the rotor 14. The stator 13 has a set of windings 17. The rotor and stator form a brushless motor, commonly referred to as "brushless". This type of engine generates high torque, and is very reliable and not subject to wear, in the absence of friction parts. The motor 12, and in particular the rotor 14, is directly linked to the pulley 10, for example by nuts distributed around the perimeter of the pulley 10 and of the rotor 14. Thus, any rotational movement of the rotor 14 is transmitted directly to the pulley 10, and vice versa.

The shaft 18 is immobilized in rotation with respect to the pulley 10 by means of a key. An encoder 24 is linked to the shaft 18, and thus makes it possible to characterize the rotation of the pulley 10.

The shaft 18 is advantageously mounted on bearings, in particular vis-à-vis the stator 13. For example, two ball bearings 19 allow free rotation of the shaft (and therefore of the pulley 10 and of the rotor 13) in the shaft. 'reel.

The reel further comprises a disc 21, rigidly linked to the pulley 10 by means of spacers 22.

The disc 21 constitutes, in cooperation with a caliper 23, a disc brake making it possible to slow down or block the rotation of the pulley 10. This brake can be actuated as a safety device, for example in the event of stopping the supply. of the belay device, for example to slow the rotation of the pulley in the event of a fall of a climber secured by the belay device.

The assembly consisting of the motor 12, the frame 9, the pulley 10 and the disc 21, is included between two flanges 22 fixed together through spacers, which are for example distributed around the periphery of the flanges 22.

In a variant, the disc 21 can serve as an encoder wheel which makes it possible, using one or more optical sensors, to characterize the rotation (angle of rotation, and / or speed of rotation) of the pulley 10. The information on the rotation of the pulley 10 makes it possible to determine the speed of winding or unwinding of the rope 3, in particular the linear speed of entry or exit of the rope. rope in the reel housing.

The electronic circuit 15 is positioned outside the mechanical part of the system located between the two flanges 22, but could according to other embodiments be located differently, in particular between the flanges 22.

Unlike known belay devices, braking during a fall of a climber provided by the device is achieved by applying a suitable torque to the pulley by the motor 12. In addition, the belay device allows climbing assistance, also by applying torque by the motor to the pulley.

The use of a motor makes it possible to precisely and dynamically control the torque applied to the pulley according to various modes of operation of the device and according to the force exerted by the rope 3 on the belay device.

In a fall mode, the belay device must limit the climber's fall speed to a safe speed, that is, a speed at which the climber can land safely on the ground. A speed of 1.8 m / s, or 6 feet per second, is considered suitable. The device can thus offer a fall speed, which can optionally be programmed, of 1 m / s, 1, 8 m / s, 2 m / s, or 3 m / s, these values being given by way of non-limiting examples. .

For this fall mode, the torque to be applied by the motor depends on the climber using the device as well as on the geometry of the pulley, and in particular on its diameter. For a fall blocking, a torque is applied applying the rope a force opposite and equal to the force exerted by the climber (typically his weight). For a given fall speed, the applied torque is modulated to maintain the desired maximum fall speed.

The servo motor, by dynamic management of the torque applied to the pulley, can also allow dynamic belaying of the climber. Typically, beyond a certain climbed height, which can be determined by the amount of rope 3 wound into the reel from the start of an ascent, it may be more comfortable and safer for the climber not to stop. suddenly fall, but ensure gradual braking until an acceptable fall speed is reached. In the context of traditional belaying, carried out by a belayer located at the bottom of the wall, this is obtained by making a little slack in the rope before slow down the climber's fall. Such behavior can be reproduced automatically, programmed, by the belay device proposed in the invention.

A fall situation can be detected by the unwinding of the rope 3, which results in a given direction of rotation of the pulley 10. As an alternative, or in addition to this parameter, the acceleration of the rotation of the pulley and / or the torque or the torque variation applied by the rope 3 to the pulley can be determined and used.

One of the primary functions of an automatic reel belay device is to allow the rope to be gradually rewound as the climber ascends. The proposed device allows this basic function to be fulfilled without providing any assistance, that is to say without applying a pulling force to the climber or at least without applying a significant pulling force. Typically, the servo motor can be programmed to wind the rope with a very low torque applied to the pulley, and or be programmed to stop its winding as soon as the reaction of the rope 3 on the pulley 10 increases.

The belay device also makes it possible to provide climbing assistance, in an assistance mode, by pulling the rope 3. Such pulling reduces the climber's apparent weight; and facilitates its ascent. The motor can be controlled, programmed, so as to dynamically adapt the assistance provided, according to various laws or various parameters.

The climber may wish assistance in the context of sports training in climbing, for example to modulate the efforts in a training program, to work on his climbing technique without the constraint of significant efforts, or on physically demanding passages or sequences. In these and other cases, permanent pulling on the rope may be bothersome or unwanted. The device makes it possible to apply traction only as assistance to an effort, that is to say to ensure that the assistance is only offered in response to an effort by the climber, and modulated depending on the force detected.

For example, the application of traction on the rope by the motor can be limited to situations in which the servo device, via an encoder, detects a rotation of the pulley reflecting a decrease in the force applied by the rope on pulley. The reduction, compared to an initial or reference situation, corresponds to the fact that when climbing, the climber applies part of his weight to the climbing holds or more generally of the weight he was exerting on the rope, and therefore realizes an effort tending to hoist it. The force applied by the rope on the pulley being the result of the force exerted by the climber and the reaction of the rope to the force applied by the pulley, it corresponds at all times to the climber's weight minus the part of this weight supported at climbing holds, and can at any time be compared to a predefined value to determine whether the climber is climbing or not. Thus, assistance can only be provided when the climber is exerting an effort, just as assist devices of electric bicycles do, by analogy, which only provide assistance when pedaling is detected.

The decrease in the force exerted by the rope on the pulley can be described by several parameters, in particular the absolute value of this decrease, by its rate compared to an initial value, or by its speed. These parameters can be determined by observing the rotation of the pulley. These settings can also be combined, one with another or all three, to determine the level of assistance to apply. The level of assistance is advantageously dynamically modulated according to the evolution of one or more of these parameters.

In particular, assistance can only be implemented when there is a sufficient predefined offset between the force exerted by the rope on the pulley and a reference force is observed. This offset allows the climber to be assisted only after a certain level of effort has been provided. This is to avoid the untimely implementation of assistance. This can also make it possible to define, for example, a constant value of an effort to be produced by the climber, the difference between this value and the force necessary for climbing being provided by the assistance function of the belay device.

The assistance offered may also take into account a calibration value. This value can be fixed, by default, or programmed according to the user. For example, the user's weight, or a predefined fraction of the user's weight, can be taken as a calibration value.

Other engine control laws may be contemplated within the scope of the invention. For example, the motor can be slaved so that the climbing speed of the climber is constant. This type of assistance is not very suitable for the practice of sport climbing, but can, in some cases, be adapted to a fun climbing activity.

FIG. 3 illustrates a belay device for climbing according to one embodiment of the invention. According to this embodiment, the reel can be move laterally at the top of the climbing wall 25 to accompany a lateral movement of the climber which is ensured.

The transverse direction T is defined as a direction perpendicular to the vertical V, that is to say the direction of application of gravity or the general direction of extension of the belay rope. The transverse direction extends in the general extension plane of the climbing wall considered.

In the embodiment of Fig. 3, the automatic reel 1 is mounted via a mounting bracket 5 fitted on a rail 26 extending in the transverse direction T. The automatic reel moves freely on the rail 26, from so that its movement accompanies the lateral movements of the climber.

Figure 4 illustrates a variant of the principle illustrated in Figure 3. In the embodiment of Figure 4, the automatic reel 1 offering a climbing assistance function is mounted on a swivel arm 27, which allows its

transverse movement. Although the movement is not purely transverse, the device can be configured to allow adequate transverse movement, and has the advantage of great simplicity and reliability.

Figure 5 illustrates another aspect of the invention, according to which the belay device allowing climbing assistance is employed in a

virtual or augmented reality environment. Indeed, because of the assistance that can be provided, as well as the comfort and high level of safety offered, the proposed belay device is particularly suitable for more fun uses than the traditional practice of climbing.

The invention thus also relates to a fun climbing system shown in FIG. 5. In addition to the belay device comprising an automatic reel 1, the device comprises a computer system 28 programmed to apply to a climbing structure 29 (by example a climbing wall) a virtual environment.

The virtual environment can be applied by means of a projector 30. This is referred to as augmented reality.

The environment can be applied via a virtual reality headset 31, this is called virtual reality.

The projector and the virtual reality headset can be used as an alternative or as a complement, for example to concomitantly allow the climber's immersion in the virtual environment and a visualization by spectators of the virtual environment in which the climber is placed. The virtual environment can be of any type, for example a

natural environment (cliff, virtual tree 33, etc.) or an urban environment (facade of a building, monument, etc.).

The virtual environments are advantageously created so that the holds of the virtual environment correspond, in position and form, to the real holds of the climbing structure 29.

The set may include means to make the virtual environment dynamic, depending on the actions of the climber. For this, sensors are used to determine the position and attitude of the climber. These may be sensors positioned on the climber, and / or one or more cameras associated with image processing software. It is thus possible to vary the environment, projected on the climbing structure 29 or in a virtual reality headset, to adapt it to certain actions of the climber. It is also possible to provide the climber with a virtual reality headset with visual feedback on the position of his own limbs in the virtual environment.

A playful climbing system as proposed according to this aspect of the invention makes it possible to offer a new climbing experience, playful or for educational purposes (for example for an adaptation to the sensation of vertigo) or even a completely playful experience: climbing effortlessly in unusual virtual environments, jumping from tree to virtual tree, between virtual buildings, etc., for example like a superhero capable of superhuman physical prowess.

The climbing belay device developed in the invention thus provides a simple and safe automatic reel belay device for climbing without a belay device. It makes it possible to achieve, by one and the same means, namely a servo motor using an encoder coupled to the reel pulley, both a belay function in the event of a fall, and a climbing assistance. The use of a servo motor makes it possible to obtain the necessary torque to be applied to the pulley for these two functions, and the modulation of this torque according to various motor servo laws, in order to meet the uses and the purpose of the motor. device in the practice of climbing as a sport, leisure or fun activity.

By its very simple configuration and the functions it offers, the device is suitable for use in a fun climbing assembly allowing a virtual environment to be applied to a real climbing structure, to offer new experiences and / or fun for the climber.

Claims

1. Belay device for climbing comprising an automatic reel (1) comprising a pulley (10) and a rope (3), the device being configured so that the rope (3) is wound or unwound according to the evolution. a climber insured by the said belay device,

characterized in that the belay device comprises:

an electric motor (12) configured so as to be able to apply a torque to the pulley (10) and an encoder coupled to the pulley, the motor being controlled by an electronic control circuit using the encoder according to the rotation of the pulley (10) so as to modulate said torque applied to the pulley according to at least:

- an assistance mode in which the torque applied by the motor to the pulley (10) pulls the rope (3) which assists the climber in his climb; and

- a fall mode in which the torque applied by the motor to the pulley (10) blocks a fall by the climber or slows it down to maintain it at a speed lower than 3 m / s.

2. Device according to claim 1, wherein the motor (12) is controlled so that the torque driving the traction in the assistance mode is applied only when said encoder detects a rotation of the pulley which reflects a decrease in the force applied by the rope (3) on the pulley (10).

3. Device according to claim 2, wherein the value of the torque applied by the motor (12) to the pulley (10) in the assistance mode is a function of the value, the rate, or the speed of the decrease. the force applied by the rope (3) on the pulley (10).

4. Device according to one of the preceding claims, wherein the value of the torque applied by the motor (12) to the pulley (10) in the assistance mode is a function of a predefined device calibration value.

5. Device according to one of the preceding claims, wherein the motor (12) is controlled so that, in the assistance mode, the ascent speed, corresponding to the winding speed of the rope (3) on the pulley (10) is substantially constant.

6. Device according to one of the preceding claims, wherein the motor (12) is controlled so that in the drop mode the torque applied to the pulley (10) essentially ensures a substantially constant predefined fall speed, regardless of the force applied by the rope (3) to the pulley (10).

7. Device according to claim 6, wherein the motor is controlled so that in the fall mode the torque applied to the pulley allows progressive braking of the climber before ensuring a substantially constant fall speed.

8. Device according to one of the preceding claims, wherein the motor (12) is directly linked to the pulley (10) or through a synchronous mechanical transmission.

9. Device according to one of the preceding claims, further comprising a disc brake (21) configured to be actuated automatically in the event of a power cut to said device.

10. Device according to one of the preceding claims, wherein the motor (12) is of the brushless type and comprises a rotor (14) carrying a series of permanent magnets and a stator (13) carrying a set of coils.

1 1. Device according to one of the preceding claims, characterized in that it

comprises a mechanical system allowing a displacement of the automatic reel, in a so-called transverse direction (T), perpendicular to the general direction of extension of the rope (3) outside the automatic reel (1) called vertical (V ).

12. Device according to claim 1 1, wherein the automatic reel (1) is mounted on a rail (26) extending in the transverse direction (T) so as to be able to be freely translated along said rail (26). , or on a pivoting arm (27) along an axis extending substantially in the vertical direction (V).

13. A fun climbing system comprising a climbing structure (29), a virtual reality device such as a helmet (31) or glasses, a computer system

(28) adapted to project in the virtual reality device an image applied to the structure to be climbed (29), and a belay device for climbing according to one of the preceding claims.

14. A playful climbing system comprising a climbing structure (29), an augmented reality device, a computer system (29) adapted to project an image onto the structure to be climbed, and a belay device for climbing according to one of claims 1 to 12.

15. A fun climbing system according to claim 13 or claim 14

having a sensor configured to determine the position and attitude of a climber using said playful climbing system, so as to vary the image projected in the virtual reality device or on the structure to be climbed (29).