Device for performing at least one task on a structure to be machined; the device includes a telescopic pressing element.

Description

1. Scope of the invention

[0001] The field of invention is that of the design and production of devices implemented in industry to perform various tasks on a structure to be worked on, in particular for the aeronautical industry. 2. Prior art

[0002] Many methods are commonly used to perform different tasks or operations on a structure. These may include, for example, drilling, countersinking, installing a temporary fastener, coating a rivet with sealant and then inserting the rivet into a hole drilled in the structure, or any other operation.

[0003] Mobile devices have been developed to enable tasks to be performed on complex structures such as airplanes.

[0004] Among these devices are those of the type comprising a tool placed at the end of a robotic arm to be manipulated and moved relative to the structure to be worked, the device including means of securing, such as suction cups, allowing the tool to be secured to the structure to be worked in order to take over the forces due to the completion of the task to relieve the robotic arm.

[0005] A device of this type can, for example, incorporate a drilling device to allow drilling operations to be carried out.

[0006] Some devices, called multi-tasking devices, are likely to include several functional modules, each dedicated to performing a particular task.

[0007] Such a device comprises a single output spindle capable of being driven in rotation and / or translation along the same axis via motor and control means.

[0008] This single pin can be made to cooperate alternately with the different on-board modules in order to allow the completion of a task to which they are dedicated.

[0009] Patent applications PCT / EP2020 / 069158, PCT / EP2020 / 069159, PCT / EP2020 / 069160, PCT / EP2020 / 069161, PCT / EP2020 / 069162, filed by the Applicant, describe multi-tasking devices

[0010] Document WO 2020 / 212631 A1 discloses a device for carrying out at least one task on a workable structure, said device comprising: a frame; means for fixing said frame to motorized handling means capable of moving said device at least partially in space relative to a workable structure; a spindle capable of being driven in rotation and / or translation along the same axis to carry out said at least one task; a pressure element, coaxial with said spindle, capable of exerting a compressive force against the surface of said workable structure; said pressure element comprising a first and a second element, said second element comprising a free end capable of coming into contact with said surface.

[0011] In the aerospace industry, it is common to drill holes in structures consisting of stacked sheet metal parts that will later be joined with rivets inserted through the holes. In this case, the drilling device is often equipped with a pressure element. This pressure element, which typically extends along the axis of the output spindle carrying the cutting tool, moves along this axis to press against the structure being worked on before drilling the hole. The use of the pressure element keeps the sheet metal parts pressed against each other during drilling and prevents chips from getting trapped between them.

[0012] The pressure element can be secured to the device by means of a ball joint whose axis coincides with that of the spindle.

[0013] Such a ball-jointed assembly can have the advantage of offering the possibility, by measuring the inclination of the axis of the pressing element relative to the axis of the spindle, to ensure that the axis of the spindle is orthogonal to the surface of the structure to be worked, which is the case when the pressing element is supported against the surface of the structure to be worked and the inclination of its axis relative to that of the spindle is zero.

[0014] Furthermore, for reasons of space and cost, it is generally preferable to use a small robotic arm to move a multi-tasking device. To achieve this, methods such as suction cups are used to secure the device to the structure being worked on, thus transferring the stresses from the robotic arm to the structure performing the tasks.

[0015] This robotic arm, when used with a pressure element, presses the element against the structure being worked on. To reduce the overall size of the robotic arm when a pressure element is used, it can be advantageous to mount the moving pressure element in translation along the spindle axis and to implement specific drive mechanisms. Such a setup can also be used to measure the pressing forces applied by the pressure element against the structure being worked on.

[0016] In addition to verifying the normality of the spindle relative to the structure being worked on and measuring the pressing forces of the pressing element against the structure being worked on, it can be useful to know other parameters such as: the initial distance between the effector and the surface at the moment the pressing element comes into contact with the surface; the depth of displacement of the surface when the force of the pressing element is applied to the surface.

[0017] However, to date there is no multi-task device equipped with a pressing element that allows, in a simple, efficient and compact way, to perform all of these functions.

[0018] Consequently, there is a need for improvement in this regard of multitasking devices.

[0019] Thus, the implementation of the pressure elements can be improved. 3. Objectives of the invention

[0020] The invention aims in particular to provide an effective solution to at least some of these different problems.

[0021] In particular, according to at least one embodiment, an objective of the invention is to provide a technique for improving multi-task devices equipped with a pressure element.

[0022] In particular, the invention aims, according to at least one embodiment, to provide a multi-task device equipped with a pressing element that is versatile in terms of the functionalities that can be offered.

[0023] Another objective of the invention is, according to at least one embodiment, to allow verification of the orthogonality of the spindle with respect to the surface of the structure to be worked.

[0024] Another objective of the invention is, according to at least one embodiment, to provide such a technique which makes it possible to control the pressure exerted by a pressure element on a surface against which it is compressed.

[0025] Another objective of the invention is, according to at least one embodiment, to allow evaluation of the initial distance between a multi-task device and the surface of a structure to be worked on at the moment when the pressing element comes into contact with that surface.

[0026] Another objective of the invention is, according to at least one embodiment, to allow evaluation of the depth of displacement of the surface when the force of the pressing element is applied to the surface.

[0027] Another objective of the invention is, according to at least one embodiment, to provide such a technique which is reliable, robust and compact. 4. Presentation of the invention

[0028] To this end, the invention proposes a device for performing at least one task on a structure to be worked on, said device comprising: a frame; means for fixing said frame to motorized handling means capable of moving said device at least partially in space relative to a structure to be worked; means for positioning and / or securing said device to said structure to be worked; a spindle capable of being driven in rotation and / or translation along the same axis to perform said at least one task; a pressure element, coaxial with said spindle, capable of exerting a compressive force against the surface of said structure to be worked when said device is secured to said structure by said fixing means; said pressing element comprising a first and a second element linked by a ball joint, said second element comprising a free end adapted to come into contact with said surface and said first element being movable in translation along the axis of said spindle in such a way that the second element is oriented orthogonally to said surface when it is compressed against said surface.

[0029] Thus, the invention is based on the implementation of a telescopic pressure element whose end is ball-jointed.

[0030] The combined implementation of a telescopic and spherical pressure element also offers the possibility of performing a multitude of functions, providing a versatile device, such as: The invention allows for the verification of the normality of the spindle axis relative to the surface of the workpiece; the evaluation of the force applied by the pressure element against the workpiece; the evaluation of the initial distance between the end effector and the surface at the moment the pressure element makes contact with the surface; and the evaluation of the depth of surface displacement when the pressure element's force is applied. The implementation of this invention thus provides a compact and versatile multi-tasking device equipped with a pressure element.

[0031] A device according to the invention includes means for driving said first element in translation.

[0032] When a device according to the invention is implemented to carry out a method of performing at least one task, these means can enable the implementation of a translational training step of said first element.

[0033] The said means of translational drive comprise a screw and nut system.

[0034] The said screw-nut system comprises a threaded portion formed at the periphery of said first element and a rotating threaded ring of complementary shape, said translational drive means comprising means for rotating the said ring relative to said first element which is fixed in rotation, said ring being fixed in translation along its axis relative to the frame.

[0035] A process can thus include a step of rotating said ring relative to said first element which is fixed in rotation, said ring being fixed in translation along its axis relative to the frame.

[0036] Said means of rotational drive comprise a motor connected to said ring by a cascade of gears.

[0037] According to one possible feature, a device according to the invention includes means for measuring at least one piece of information representative of the thrust along the axis of said spindle generated by said second element on said surface.

[0038] A process may thus include a step of measuring at least one piece of information representative of the thrust along the axis of said spindle generated by said second element on said surface.

[0039] According to one possible feature, a device according to the invention includes means for detecting the impact of said thrust: of a contact entry value corresponding to the thrust value at the moment of contact of the free end of the second element with said surface and, of a pressing value of said structure to be worked.

[0040] A process may therefore include a step for detecting the impact of said thrust: of a contact entry value corresponding to the thrust value at the moment of contact of the free end of the second element with said surface and, of a pressing value of said structure to be worked.

[0041] According to one possible feature, a device according to the invention includes means for measuring at least one piece of information representative of the inclination of said second element with respect to the axis of said spindle.

[0042] A process may thus include a step of measuring at least one piece of information representative of the inclination of said second element with respect to the axis of said spindle.

[0043] According to one possible characteristic, said means of measurement, of at least one information representative of the inclination, include distance sensors, for example inductive or laser or other, carried by said frame and distributed uniformly around said second element, said sensors being capable of measuring the radial displacement of said second element relative to the frame.

[0044] A process may thus include a step of measuring the radial displacement in the plane of the sensors of said second element relative to the frame.

[0045] According to one possible characteristic, the said first and second elements are tubular.

[0046] According to one possible characteristic, a reference frame is associated with the said frame, the said device including means for measuring a translational displacement of the said first element relative to the reference frame of the said frame along the axis of the said spindle.

[0047] A process may thus include a step of measuring a translational displacement of said first element with respect to the reference frame of said frame along the axis of said spindle.

[0048] According to one possible characteristic, said means for measuring the translational displacement of said first element with respect to said frame reference include a sensor for measuring the angle of rotation of the rotor of said motor.

[0049] A process may therefore include a step of measuring the angle of rotation of the rotor of said motor.

[0050] According to one possible feature, a device according to the invention includes means for determining the distance, along a direction parallel to the axis of said spindle, between the surface oriented towards said device of said structure to be worked and a reference surface of said frame in said reference frame associated with said frame, said means for determining said distance when said device is secured to said structure to be worked by said means for securing, taking into account the value of the angle provided by said angle sensor at the time when said means for detecting detects the attainment by said thrust of said contact entry value corresponding to the thrust value at the time of the contact of the free end of the second element with said surface.

[0051] A process may thus include a step of determining the distance, along a direction parallel to the axis of said spindle, between the surface oriented towards said device of said structure to be worked and a reference surface of said frame in said reference frame associated with said frame, said step of determination consisting of determining said distance when said device is secured to said structure to be worked by said means of securing, taking into account the value of the angle at the time of the attainment by said thrust of said contact value corresponding to the value of thrust at the time of the contact of the free end of the second element with said surface.

[0052] According to one possible variant, a device according to the invention includes means for measuring the deformation of said structure to be worked under said pressing force, said deformation corresponding to the translational displacement of the first element between the moments when said detection means detect that the value of said thrust passes from said contact entry value to said pressing value.

[0053] A process may thus include a step of measuring the deformation of said structure to be worked under said pressing force, said deformation corresponding to the translational displacement of the first element between the moments when the value of said thrust passes from said contact entry value to said pressing value.

[0054] According to one possible variant, a device according to the invention comprises: at least two functional modules, each of said functional modules comprising at least one moving part capable of enabling the performance of a given task; a single drive spindle movable in rotation and / or translation along the same axis and capable of cooperating individually with said moving parts to animate them with a rotational and / or translational movement enabling the performance of their given task.

[0055] According to one possible characteristic, said functional modules belong to the group comprising at least: drilling modules; modules for setting rivets coated with mastic; modules for setting temporary fixings.

[0056] The invention also covers a method of performing at least one task on a structure to be worked on by means of a device according to any one of claims 1 to 16 comprising a pressure element comprising a first and a second element linked by a ball joint, said method comprising a step of moving said first element in translation along the axis of said spindle in such a way that the second element is oriented orthogonally to said surface when it is compressed against said surface. 5. Description of the figures

[0057] Other features and advantages of the invention will become apparent from the following description of particular embodiments, given by way of simple illustration and not limitation, and the accompanying drawings, among which: [ Fig 1 ] there figure 1 illustrates a perspective view of an example of a multitasking device according to the invention; [ Fig 2 ] there figure 2illustrates a partial cross-sectional view along a plane passing through the axis of the spindle of the device. figure 1 ; Fig 3 ] there figure 3 illustrates a detailed view of the figure 1 centered on the pressing element; [ Fig 4 ] there figure 4 illustrates a cross-sectional view of the figure 3 along a plane orthogonal to the axis of the spindle; [ Fig 5 ] there figure 5 illustrates a detailed view of the figure 3 . 6. Description of specific embodiments 6.1. Architecture Means of attachment to handling equipment

[0058] We describe, in relation to the figures 1 to 4 an example of a multi-tasking device according to the invention.

[0059] As shown in these figures, such a multi-tasking device 1 comprises a frame 2.

[0060] This frame 2 is equipped with means of fixing 3 to a motorized handling device (not shown) to which it is intended to be attached so as to be able to be moved at least in part in relation to a structure to be worked on (not shown).

[0061] These motorized handling equipment belong to the group which notably includes: robotic arms; walking robots for example according to the principle described in patent document FR-B1-2 809 034; digital grids for example according to the principle described in patent document WOA-2-200349899.

[0062] Such fastening means 3 are known in themselves and are therefore not described. They may, for example, include a plate and bolt type system, quick-release clamp-type fastening means, a clamp or cam system....

[0063] Motorized handling equipment is capable of moving, at least partially (particularly when the controller is stationary), the multitasking device in space relative to the surface of the structure being worked on, between at least one approach position in which the device is close to the surface but at a distance from it, and a docking position in which the device is pressed against the surface, for example, to be secured there if securing means are implemented. It can also place the multitasking device in a storage position when it is not in use for an operation. Single output pin

[0064] The device includes a single drive spindle 7 that is movable in rotation and / or translation along the same axis.

[0065] The device also includes MT motor and transmission means to enable the spindle to undergo rotational and / or translational movement along its longitudinal axis. These motor and transmission means are known in themselves and are not described in further detail here. Controller

[0066] The device typically includes a controller 4 comprising the control and power electronics enabling the device to be controlled and powered.

[0067] This controller 4 is preferably contained in a box away from frame 2 and stored permanently on site.

[0068] Controller 4, or at least some of its components, could nevertheless be mounted on frame 2. Methods of solidarity with a structure to be worked on (optional)

[0069] The system may optionally, but preferably, include means of solidarity 5 with the structure to be worked on.

[0070] These means of solidarity can be of different types.

[0071] For example, they may include suction cups 51 attached to the frame 2 and capable of being connected to vacuum devices such as a vacuum pump to improve adhesion to the surface of the structure being worked on. These suction cups can be grouped together to form suction cup pads.

[0072] When no means of securing to the structure to be worked on is implemented, the handling device can constitute not only a means of positioning the frame in relation to the structure to be worked on but also a means of immobilizing it in position in relation to the structure to be worked on. Functional modules

[0073] The device is capable of incorporating a plurality of MF functional modules.

[0074] Each of these MF functional modules allows for a specific task to be performed, such as drilling and / or countersinking, riveting, installing temporary fasteners (e.g., staples), or applying (or coating) a bead of sealant to a fastener (rivet or screw). Other functions could be considered, such as screw driving.

[0075] Functional modules, for example, belong to the group comprising at least: drilling and / or countersinking modules; rivet setting modules with or without sealant; temporary fixing installation modules.

[0076] A temporary fastener used in the aeronautical industry is a mechanical device that allows at least two walls to be clamped together in order to carry out production operations necessary for the final assembly of these walls, such as counter-drilling or the installation of screws or rivets.

[0077] By definition, these temporary fixings are removed as the screws or rivets fulfill their function of assembling the walls.

[0078] Temporary fixings are placed in holes made in the walls after the initial relative positioning of these walls.

[0079] Temporary fixings only require access from one side of one of the walls.

[0080] Such functional modules are described in particular in patent documents PCT / EP2020 / 069158, PCT / EP2020 / 069159, PCT / EP2020 / 069160, PCT / EP2020 / 069161, PCT / EP2020 / 069162, filed by the Applicant.

[0081] The device includes means 12 for aligning the various onboard modules with the spindle 7 to perform a task. These means may, for example, include a carousel, a cartridge holder, or other similar components. Pressure element

[0082] The device comprises a tubular pressure element 6 mounted to move in translation relative to the frame 2 along the axis of movement of the spindle 7 and as an extension thereof. The pressure element is therefore coaxial with the spindle. Because it is tubular, the spindle can translate within the pressure element.

[0083] Such a pressure element 6 can for example be used during a drilling operation to exert a compressive force on the structure to be drilled, in particular to ensure contact between the plates of a stack and to prevent the introduction of chips and / or the formation of burrs between these plates during drilling.

[0084] The pressure element 6 comprises a first element 61 and a second element 62 linked by a ball joint 630 along the axis of the spindle.

[0085] The second element 62 includes a free end 620 suitable for coming into contact with the surface of the structure to be worked on.

[0086] The first element 61 is movable in translation along the axis of the spindle in such a way that the second element 62 is oriented orthogonally to the surface when it is compressed against the surface.

[0087] The pressure element comprises an intermediate element 63. The intermediate element 63 comprises an end 631 oriented towards the frame 2 to which it is fixedly attached. It comprises an opposite end 632 oriented towards the free end 620 of the second tubular element 62. The first element 61 is mounted to slide in translation inside the intermediate element along the axis of the spindle while remaining fixed against rotation about this axis. The intermediate element 63 thus serves as a means of guiding the first element 61 in translation.

[0088] The pressure element includes a ring 64. This ring is threaded. It is mounted to rotate freely but to move linearly along the axis of the spindle by being connected to the intermediate element by means of a pair of ball bearings 65.

[0089] The first tubular element 61 includes a threaded portion formed at its periphery which cooperates with the tapped portion of the ring. These tapped and threaded portions constitute a screw-nut system.

[0090] The device includes means for rotating the ring. These means include a motor 8 whose rotor comprises a shaft 81 connected to the ring 64 by means of a cascade of spur gears 82, the ring carrying a gear on its periphery. Other types of motors and transmissions could be used to rotate the ring, such as a belt drive.

[0091] The screw-nut system, the gear train and the motor constitute means of translational drive of the first tubular element 61.

[0092] The motor 8 is equipped with an angle sensor 83 capable of measuring the angle of rotation of the rotor relative to the stator. Thrust measurement applied by the pressing element

[0093] In one embodiment, the device includes means for measuring at least one piece of information representative of the thrust along the axis of the spindle generated by the second element 62 of the pressure element 6 on the surface of the structure to be worked.

[0094] In this embodiment, these measurement means include a thrust sensor 9 which includes strain gauges arranged on the first element 61. Other types of thrust sensors could alternatively be implemented.

[0095] The device also includes 10 means of detecting impact by the thrust: of a contact entry value corresponding to the thrust value at the moment of contact of the free end of the second element with the surface of the structure to be worked and, of a pressing value of the structure to be worked.

[0096] The entry thrust value corresponds to the thrust value recorded when it goes from zero to a non-zero value.

[0097] The pressing thrust value is a predetermined value to which the thrust is desired to be applied.

[0098] Possible uses of this data will be described in more detail later. Determining the deformation of the structure under the pressure exerted by the pressing element

[0099] In one embodiment, the device includes means for measuring 11 the deformation of the structure to be worked under said pressing force.

[0100] The deformation measured by these measuring means corresponds to the translational displacement of the first element 61 between the moments when the detection means detect that the value of the thrust changes from the contact entry value to the pressing value. Measurement of the pressure element's inclination

[0101] In one embodiment, the device includes means 12 for measuring at least one piece of information representative of the inclination of the second element 62 with respect to the axis of the spindle.

[0102] In this embodiment, the means for measuring at least one information representative of the inclination include inductive sensors 120. In a variant, it could be laser or other sensors.

[0103] These inductive sensors are mounted on the frame and distributed uniformly around the second element 62. They are capable of measuring the radial displacement of the second element 62 relative to the first element 61. Preferably, there are three of these sensors. This radial displacement is measured in the median plane PM of the sensors, which is itself located at a distance L from the pivot point CP of the first pressure element 61. The radial displacement is not necessarily in the plane of one of the sensors; therefore, it is calculated from the signals provided by two of the sensors, possibly correlated with the signal from the third sensor. Analysis of these signals allows us to determine the eccentricity of the pressure element section located in the median plane of the sensors, as well as the orientation of the displacement of said section in the median plane.

[0104] It is thus possible to determine the value of the inclination as well as the orientation of the plane in which the inclination occurs. The calculation of the inclination follows established geometric rules and will not be detailed further here.

[0105] Implementing these methods for measuring the inclination of the pressure element makes it possible to determine whether the pressure element is coaxial or inclined relative to the spindle.

[0106] A maximum inclination value is predefined. If the actual inclination is less than this value, the inclination is simply recorded and drilling continues. If the actual inclination is greater than the predetermined value, the positioning of the end effector relative to the workpiece surface is adjusted.

[0107] If the actual inclination is zero, then the spindle is orthogonal to the surface of the structure being worked on. Measurement of the exit distance of the pressure element

[0108] In one embodiment, a frame is associated with the frame, one of whose three axes is parallel to the spindle axis, and the origin can be located at the intersection between the spindle axis and a reference surface of the end effector frame perpendicular to the spindle axis.

[0109] In this case, the device includes means 13 for measuring a translational displacement of the first element 61 of the pressure element 6 relative to the frame reference along the axis of the spindle.

[0110] In this embodiment, these means of measuring the translational displacement of the first element relative to the frame reference include the sensor for measuring the angle of rotation of the motor rotor used to drive the ring 64 in rotation and therefore the pressure element 6 in translation.

[0111] Thus, the angle values ​​provided by the motor's angle sensor can be used to calculate the distance between the free end of the second element 62 of the pressure element and the origin of the coordinate system according to the following formula: Distance surface / origine = Angle mesuré × Const 1 + Const 2

[0112] Constants 1 and 2 are determined from the geometric characteristics of the effector including the pitch of the screw-nut system described above, the transmission ratio between the motor and the ring, the angular position of the motor angle sensor corresponding to the zero of the angle etc. Determining the distance between the surface of the structure to be worked on and the device

[0113] In one embodiment, the device includes means 14 for determining the distance, along a direction parallel to the axis of the spindle, between the surface oriented towards the device of the structure to be worked and the reference surface of the frame in the reference frame associated with said frame.

[0114] In this case, the reference point mentioned previously for measuring the exit distance of the pressure element can be used to determine the distance between the surface of the structure to be worked and the device.

[0115] These determination means are capable of determining this distance when the device is secured to the structure being worked on by the fastening means. To do this, they take into account the angle value provided by the angle sensor 83 at the moment the detection means detect that the thrust reaches the contact value corresponding to the thrust value at the moment the free end of the second element makes contact with the surface of the structure being worked on, in order to determine this distance according to the following formula: Distance surface / bâti = Angle mesuré × Const 3 + Const 4

[0116] Constants 3 and 4 are determined from the geometric characteristics of the effector including the pitch of the screw-nut system described above, the transmission ratio between the motor and the ring, the angular position of the motor angle sensor corresponding to the zero of the angle etc. 6.2. Operation

[0117] To perform a task on a structure to be worked on, handling equipment is first used to move the multi-task device to the location on the structure where the task is to be performed.

[0118] This initial approach is based on the fact that the control means of the handling means know the geometry of the structure to be worked on and are therefore able to position the effector where the hole needs to be made.

[0119] Following this initial approach, the multi-task device is in a position such that the axis of the spindle is substantially coaxial with the axis of the hole to be made, the said device remaining a certain distance away from the surface of the structure to be treated.

[0120] However, given the various inaccuracies of the handling equipment and the structure, the position of the effector in relation to the structure must be refined by using reference elements previously provided or placed on the structure to be worked on to identify the place(s) where tasks must be carried out.

[0121] Means of checking the orthogonality of the spindle axis relative to the surface, such as a camera mounted coaxially to the spindle and coupled to lasers projecting a pattern onto the surface of the structure, are implemented to verify whether or not the spindle axis is orthogonal to the surface. If not, the orientation of the device is modified using handling means to correct the inclination of the spindle axis relative to the surface.

[0122] A misalignment of the spindle axis with respect to the locating element can also be determined using the camera and is corrected accordingly by moving the multi-tasking device parallel to the surface.

[0123] If the initial locating element is a pre-existing hole, the handling means begin by centering the end effector spindle on this hole and then move the multi-tasking device relative to this hole to reach the location of the hole to be made, the relative positioning of these holes being known by the control means of the handling means.

[0124] Once the device position and spindle orthogonality are correct, the device is moved from its approach position to its docking position by the handling means in a direction normal to the surface.

[0125] The means of securing, for example suction cups, are activated where necessary to secure the frame to the structure to be worked on.

[0126] Following the clamping process, the pressure element is moved towards the surface of the structure being worked in order to press it against the surface. To achieve this, the motor 8 is driven to rotate the ring 64. Under the effect of the rotation of the ring 64, the first element 61 of the pressure element translates along the axis of the spindle towards the surface of the structure being worked. The free end 620 of the second element 62 gradually comes into contact with the surface, inducing, through a hinge effect, the application of the end 620 of the second element 62 against the surface of the structure being worked.

[0127] Throughout the deployment of the pressure element 6, the means for measuring the translational displacement of the pressure element measure the angle of rotation of the motor.

[0128] The means of measuring the thrust measure the thrust until they detect the instant at which the value of the thrust exerted on the surface by the pressing element reaches the value of entry into contact.

[0129] The means for determining the distance, along a direction parallel to the axis of the spindle, between the surface oriented towards the device of the structure to be worked and the reference surface of the frame then determine this distance by taking into account the value of the angle provided by the angle sensor at the moment when said detection means detect the reaching by the thrust of the contact entry value corresponding to the thrust value at the moment of the contact of the free end of the second element with the surface.

[0130] Knowing the deployment distance of the pressure element and / or the distance between the surface of the structure being worked on and the reference surface of the frame allows verification that the device is correctly positioned relative to the surface. A deployment that is too small or too large compared to the theoretical relative position of the device with respect to the surface may indicate incorrect positioning, necessitating correction of the device's position after disengaging the securing means. In this case, the controller commands the device to perform the required position correction.

[0131] The pressing element continues to be deployed until the thrust measurement means detect that the thrust has reached the predetermined pressing value corresponding to the pressure that is desired to be applied against the surface of the structure to be worked on.

[0132] The means of measuring the inclination determine the inclination of the pressing element relative to the axis of the spindle.

[0133] In one variant, the inclination of the axis of the pressure element relative to that of the spindle is measured and then: If the inclination is less than a first predetermined value, the drilling is carried out and the value of the defect (i.e. the inclination) is recorded; if the inclination is greater than a second predetermined value, the process of positioning the device is restarted.

[0134] The means for measuring the deformation of the structure being worked determine, when the thrust reaches the pressing value, the deformation undergone by the structure under the effect of the pressure imposed by the pressing element. This deformation corresponds to the translational displacement of the first element 61 between the moments when the detection means detect that the thrust value changes from the initial contact value to the pressing value. This deformation can be compared to a reference value to ensure that the deformation imparted to the structure being worked is adequate.

[0135] The module corresponding to the operation to be performed is placed in the axis of the spindle and then coupled to it.

[0136] The spindle is then moved to perform the desired operation, for example drilling and / or countersinking, installing a coated or uncoated rivet, installing a temporary fixing...

[0137] Once the operation is completed, the spindle is disconnected from the functional module and then the functional module is moved so that it is no longer in line with the spindle.

[0138] Other tasks can then be carried out in the same place (for example, setting a rivet in a hole) or in another place on the structure being worked on.

Claims

1. Device for carrying out at least one task on a structure to be worked, said device comprising: - a frame (2); - means (3) for fastening said frame (2) to motor-driven handling means capable of at least partly moving said device in space relative to a structure to be worked; - means (5) for positioning and / or securing said device to said structure to be worked; - a spindle (7) capable of being driven in rotation and / or in translation along the same axis to carry out said at least one task; - a pressing element (6), coaxial with said spindle (7), capable of exerting a compressive force against the surface of said structure to be worked when said device is secured to said structure by said means for positioning and / or securing (5); said pressing element comprising a first (61) and a second (62) element connected by a ball joint connection (630), said second element (62) comprising a free end (620) capable of coming into contact with said surface and said first element (61) being movable in translation along the axis of said spindle (7) so that the second element (62) orients orthogonally to said surface when compressed against said surface, said device comprising means for translational driving of said first element (61), said means for translational driving comprising a screw-nut system, said screw-nut system comprising a threaded portion provided at the periphery of said first element (61) and a threaded ring (64) movable in rotation with a complementary shape, said means for translational driving comprising means for rotational driving of said ring (64) with respect to said first element (61) immobilised in rotation, said ring (64) being immobilised in translation along its axis with respect to the frame (2), said means for rotational driving comprise a motor (8) connected to said ring (64) by a cascade of pinions (82).

2. Device according to claim 1, comprising means for measuring at least one piece of information representative of the thrust along the axis of said spindle (7) generated by said second element (62) on said surface.

3. Device according to claim 2, comprising means (10) for detecting when said thrust reaches: - a coming-into-contact value corresponding to the thrust value at the time the free end (620) of the second element (62) comes into contact with said surface, and - a value of pressing of said structure to be worked.

4. Device according to any one of claims 1 to 3, comprising means (12) for measuring at least one piece of information representative of the inclination of said second element (62) relative to the axis of said spindle (7).

5. Device according to claim 4, wherein said means (12) fr measuring at least one piece of information representative of the inclination comprise distance sensors carried by said frame (2) and distributed uniformly around said second element (62), said sensors being able to measure the radial movement of said second element (62) relative to the frame (2).

6. Device according to any one of claims 1 to 5, wherein said first (61) and second element (62) are tubular.

7. Device according to any one of claims 1 to 6, wherein a reference frame is associated with said frame (2), said device comprising means for measuring a translational movement of said first element (61) with respect to the reference frame of said frame (2) along the axis of said spindle (7).

8. Device according to claims 2 and 7 in combination or not with any one of claims 3 to 6, wherein said means for measuring the translational movement (13) of said first element (61) with respect to said reference frame of said frame (2) comprise a sensor (83) for measuring the angle of rotation of the rotor of said motor (8).

9. Device according to claims 2, 3 and 8 in combination or not with any one of claims 4 to 7, comprising means for determining the distance (14), along a direction parallel to the axis of said spindle (7), between the surface oriented towards said device of said structure to be worked and a reference surface of said frame (2) in said reference frame associated with said frame (2), said means (14) for determining determining said distance when said device is secured to said structure to be worked by said securing means (5), taking into account the value of the angle provided by said angle sensor (83) at the time when said means (10) for detecting detect the reaching by said thrust of said coming-into-contact value corresponding to the thrust value at the time of the coming into contact of the free end (620) of the second element (62) with said surface.

10. Device according to claims 2 and 3 in combination or not with any one of claims 4 to 9, comprising means (11) for measuring the deformation of said structure to be worked under said compressive force, said deformation corresponding to the translational movement of the first element (61) between the times when said means (10) for detecting detect that the value of said thrust changes from said coming-into-contact value to said value of pressing.

11. Device according to any one of claims 1 to 10, wherein said device is of the multi-task type and comprises: - at least two functional modules, each of said functional modules comprising at least one movable member that can allow carrying out a given task; - one single driving spindle (7) movable in rotation and / or in translation along the same axis and capable of cooperating individually with said movable members in order to drive them in a rotational and / or translational movement enabling them to carry out their given task.

12. Device according to any one of claim 11, wherein said functional modules belong to the group comprising at least: - drilling modules; - modules for placing rivets coated or not with mastic; - modules for placing temporary fasteners.