Apparatus and method for manufacturing green tires

Abstract

The invention relates to an apparatus (10) for manufacturing green tyres, comprising a rotatable and movable drum (16) for manufacturing green tyres, a platform (21) arranged upstream of said drum (16) and comprising a flat surface (21a) for receiving one end of an elastomeric element, at least one robot arm (18), an ECU (40) and at least one first 3D camera, the robot arm (18) is configured to clamp an end portion of an elastomeric element from above and comprises at least three rows of elements made of magnetic material, the ECU (40) is configured to control the robot arm (18), and the first 3D camera is configured to acquire an image of the end portion of the elastomeric element on the platform (21).

Description

Technical Field

[0001] The present invention relates to the field of tire manufacturing, and more particularly to a method for manufacturing a green tire and an apparatus for carrying out such a method. Background Art

[0002] The tire of a motor vehicle wheel generally comprises three distinct areas: a crown comprising the crown reinforcement and the tread intended to come into contact with the ground; beads intended to attach the tire to the rim of the wheel; and sidewalls intended to connect said crown to said beads.

[0003] The tyre further comprises a metal or textile fiber structure forming a carcass, serving to reinforce the structure of the tyre and allowing the crown to be connected to the beads.

[0004] The manufacture of a green tire involves sequentially assembling elements in the form of bead wires, strips, or plies to form a cylindrical carcass reinforcement. This cylindrical carcass reinforcement is then transformed into a toroidal carcass reinforcement in a step known as "forming." During this step, the crown portion of the cylindrical carcass reinforcement is stretched so that its diameter increases, and the bead portions are moved axially toward each other. Finally, elements in the form of strips or plies are sequentially assembled onto the crown portion of the carcass reinforcement, forming the crown reinforcement and, on top, the tread.

[0005] The assembly and shaping steps are typically carried out on a drum for producing a cylindrical green tire, which is rotatable about an axis of rotational symmetry. The elements, in the form of threads, strips, or plies, are laid circumferentially onto the drum or onto the green tire being produced. This laying step is performed manually or automatically.

[0006] When the layup step is performed manually, an operator facing the drum grasps the end portion of an element (e.g., a ply wound on a reel), pulls it onto the drum, and positions and secures it to the drum or the green tire being built. The drum is then rotated for one complete revolution. During the drum's rotation, the operator guides the ply so that the windings form a substantially straight cylinder. The operator then cuts the ply and adjusts the joint between the two ends of the ply.

[0007] However, performing the laying step manually has many disadvantages. The operator has limits in terms of speed and precision. Furthermore, approaching or exceeding these limits makes the operator's work more tedious and mentally exhausting, which can be detrimental to the quality of the green tire being produced or even the operator's safety.

[0008] On the other hand, the automation of the manually performed laying step also presents technical problems, in particular designing a manufacturing machine capable of carrying out said laying step and, above all, programming said machine so that it can carry out said laying step.

[0009] Some machines for manufacturing green tires are known in which a drum is moved between multiple laying stations by means of a carriage or robotic arm. Each laying station is adapted to lay a specific component, such as a bead wire or a strip. Because each station has a different production rate, the faster laying stations are underutilized, impairing their efficiency. Furthermore, the design, construction, and operation of such assembly machines are very complex and expensive.

[0010] Some machines for manufacturing green tires are also known that comprise only two laying stations, each suitable for laying a group of preassembled elements. Thus, two complete rotations of the drum are sufficient to lay a first group intended to constitute the carcass reinforcement and a second group intended to constitute the crown reinforcement and the tread. However, such manufacturing machines require adaptations to the structure and composition of the green tire itself, which severely limits tire design and industrialization processes.

[0011] Document FR-B1-3116227 is also known, which proposes the automated placement of elastomeric elements on a drum for manufacturing green tires, comprising a predetermined sequence of steps in which the elastomeric element is gripped by a robotic arm including an actuator and pulled toward the drum. However, this document proposes a collaborative robotic arm, in other words, one that collaborates with an operator who manually performs the steps following the interruption in the sequence.

[0012] Furthermore, this document does not describe how the laying step is performed.

[0013] Specifically, the mechanical reinforcement of the elastomeric element, combined with the fact that it is wound on a reel, results in an end surface that is not completely flat after being unwound for placement on the drum's outer surface. Furthermore, the element's stiffness can affect the lateral position of its end when unwound onto a flat surface. In other words, the lateral position of the tip of the unwound elastomeric element can be angularly offset from the axial axis, which is perpendicular to the drum's axis of rotation.

[0014] There is therefore a need to overcome the above-mentioned drawbacks and to automate the machines for manufacturing green tyres while improving the laying of the elastomeric elements and maintaining satisfactory reliability and productivity. Summary of the Invention

[0015] The present invention aims to improve the laying of elastomeric elements, in particular the clamping of the elastomeric elements upstream of a drum, and the anchoring of said elastomeric elements on said drum.

[0016] The present invention also aims to improve the cutting of elastomeric elements.

[0017] The invention relates to an apparatus for manufacturing a green tyre, the apparatus being associated with a first orthogonal reference system and comprising a drum for manufacturing the green tyre, the drum being rotatable about an axis of rotation of the first reference system, a platform arranged upstream of the drum, at least one robotic arm, and an electronic control unit ECU, the platform extending along a transverse axis of the first reference system and comprising a flat receiving surface for receiving an end portion of an elastomeric element or a ply, the electronic control unit ECU being configured to operate the robotic arm.

[0018] The apparatus further includes at least a first three-dimensional camera that generates a coordinate point cloud measured in a reference frame associated with the first camera, has a line of sight toward the platform, and is configured to acquire an image of an end portion of the elastomeric element on the platform.

[0019] The robotic arm comprises at least one gripper associated with a second orthogonal reference frame different from the first reference frame and configured to grip an end portion of the elastomeric element from above.

[0020] The holder comprises at least three rows of magnetic elements or magnets which are parallel to each other and regularly spaced apart from each other along the axis of extension of the second reference system.

[0021] The ECU includes at least:

[0022] a gripping module for gripping an end portion of the elastomeric element and configured to determine a gripping point of the gripper based on the point cloud generated by the first camera, and

[0023] an anchoring module for anchoring said end portion on the outer surface of the drum and configured to determine the anchoring point of each row of magnetic elements on the outer surface of the drum.

[0024] Thus, unlike prior art multi-station automated assembly machines where each station is dedicated to laying down a specific component or pre-assembled assembly, the assembly apparatus is flexible.

[0025] Furthermore, the robotic arm is more precise and faster than a human operator, which improves the quality of the green tires produced and increases the effective time of the manufacturing equipment. The term "effective time" means the net time, excluding the time associated with producing a green tire that does not meet the quality requirements. The term "net time" means the time it takes the machine to produce a green tire, excluding time associated with production rate interruptions or failures.

[0026] The tip of the elastomeric element or ply corresponds to the end of the end portion (for example triangular) of the elastomeric element. In other words, the tip corresponds to the apex or peak of said end portion.

[0027] For example, the end portion extends along an extension axis of the second reference system, which extension axis is angularly offset from the transverse axis of the first reference system.

[0028] The angle of angular offset between the axis of extension of the second reference frame and the transverse axis of the first reference frame is preferably non-zero.

[0029] Advantageously, the clamping module comprises:

[0030] - an acquisition module for acquiring an image of the end portion of the elastomeric element on the platform by means of a first camera,

[0031] a segmentation module for segmenting the image of the end portion of the elastomeric element on the platform into three regions, and

[0032] a determination module for determining the position of the gripper, in particular the position of the gripping point, and comprising a first image processor configured to: determine an initial gripping point in the point cloud of the image from the acquisition module, correct the initial gripping point by translating it by a distance corresponding to the radius of the magnet of the gripper along an extension axis of a second reference system and along a second longitudinal axis of the second reference system perpendicular to the extension axis, and determine the gripping point that is transmitted to the robotic arm by the transmission module.

[0033] This translation makes it possible to increase the surface area of ​​the holder available for magnetization together with the end portion of the elastomeric element.

[0034] The three regions of the visible end portion on the platform include a first region corresponding to the region between the tip or peak of the end portion and a second region between the first region and a third region between the second region and the edge of the platform.

[0035] The total length of the end portion of the elastomeric element corresponds to the distance between the tip of said end portion and the edge of the platform.

[0036] Preferably, the first region and the third region each correspond to 30% of the total length. Alternatively, the length of the first region may be different from the length of the third region. For example, the length of the first region may be between 20% and 30% of the total length, and the length of the third region may be between 20% and 30% of the total length.

[0037] According to an embodiment, the determination means for determining the position of the gripper is configured to determine a straight line passing through a side of the second region, the gripping point being offset a distance from the tip of the end portion in the axial direction.

[0038] According to an embodiment, the device comprises a first fixed vertical laser, which indicates the center of the drum, a second fixed horizontal laser, which indicates the azimuth of the laying of the elastomeric elements, and two variable vertical lateral lasers, which indicate the longitude of the laying, the lasers being rigidly fixed to the fixed structure or gantry of the device. The anchoring module comprises a module for projecting the lasers onto the outer surface of the drum, in particular onto the laying area at the ends of the elastomeric elements.

[0039] For example, the apparatus includes a second three-dimensional camera generating a coordinate point cloud measured in a reference frame associated with the second camera, having a line of sight towards the drum and configured to acquire images of a paved area on the outer surface of the drum.

[0040] The anchor module includes:

[0041] - an acquisition module, which is used to acquire an image of the paving area by means of the second camera, and

[0042] - A module for processing the image of the paving area, configured to detect the lasers, the intersection pixels at the intersection between the second horizontal laser and one of the side lasers (i.e., the right side laser if the end portion of the elastomeric element is facing the right, or the left side laser if the end portion is facing the left), and the intermediate pixels at the intersection of the first horizontal vertical laser and the second horizontal laser, to estimate the intersection point and the intermediate point corresponding to the three-dimensional point of the intersection pixel and the intermediate pixel of the drum.

[0043] Advantageously, the anchoring module comprises:

[0044] a module configured to determine, based on the distance between the two rows of magnets and the radius of the magnets, the anchor point of each magnet relative to the point of intersection in the plane normal to the plane where the circle fitted on the point cloud of one side laser lies,

[0045] a module for transmitting said anchor point to a control module for controlling the gripper and configured to control the array of magnets of the gripper, in particular the actuator of each magnet, respectively.

[0046] For example, the ECU includes a supporting module for supporting the elastomeric element around the drum, a cutting module for cutting the elastomeric element into desired lengths, and a welding module for welding the cut portions of the elastomeric element to end portions anchored on the outer surface of the drum.

[0047] According to an embodiment, the gripper of the robotic arm comprises actuators each connected to a magnet, said actuators being individually controlled to sequentially release the third row of magnets, the second row of magnets, and then the first row of magnets.

[0048] When anchoring the end portions of the elastomeric elements on the drum, it is preferred that the actuators are deactivated row by row in order to release the anchoring areas of the elastomeric elements.

[0049] The anchoring module makes it possible to anchor a product of complex shape on a circular shape (ie a drum) by determining three anchor points belonging to the same circle.

[0050] The magnetic element of the gripper of the robot arm is preferably mounted on a bracket configured to be connected to the end portion of one or more robot arms (in case there are two robot arms).

[0051] According to an embodiment, the first row of magnetic elements, the second row of magnetic elements, and the third row of magnetic elements each include at least one magnetic element.

[0052] According to another embodiment, the first row of magnetic elements and the second row of magnetic elements of the gripper of the robotic arm each include a single magnetic element.

[0053] For example, the third row includes at least three magnetic elements or magnets, and one magnetic element of the third row is aligned along the extension axis with the magnetic elements of the first and second rows.

[0054] For example, the set of magnetic elements is arranged in a T-forming manner.

[0055] Typically, the shape of the holder is symmetrical.

[0056] By means of the symmetrical arrangement of the clamps, the same clamp can be used to clamp the end portion of the elastomeric element facing towards the right or the end portion of the elastomeric element facing towards the left.

[0057] Alternatively, provision can be made for the holder to comprise a different number of magnetic elements, for example greater than or equal to six magnetic elements.

[0058] The magnetic element may have a circular or rectangular cross-section or any other cross-section.

[0059] According to an embodiment, the apparatus includes a second robotic arm. A single robotic arm is required for both the clamping and anchoring steps. However, the presence of the second robotic arm allows for clamping the distal end of the end portion of the elastomeric element oriented in the second direction. The second robotic arm is also used during the cutting step to hold the end portion against the drum.

[0060] For example, a first 3D camera (eg, an RGB-D sensor) is fixed, pointing upstream toward the platform and attached to a fixed structure or gantry.

[0061] The first 3D camera is advantageously used for the laying step and the clamping step.

[0062] The first 3D camera makes it possible to avoid the recalibration required when using a 2D camera. Specifically, the first 3D camera can immediately match the distance of an object and its perceived size, thereby making it possible to measure the size of an object without having to indicate the depth of the object relative to the camera.

[0063] For example, the second 3D camera (eg an RGB-D sensor) is fixed, pointed towards the drum and is particularly attached to a fixed structure or gantry.

[0064] The second 3D camera is advantageously used for the anchoring step, the cutting step and the welding step.

[0065] The RGB-D 3D camera is advantageously calibrated or standardized only with respect to the robot arm and not the environment, because the camera detects the environment in three dimensions and can measure and determine the position and orientation of elements in its field of view, which allows the platform to be oriented in different orientations. In other words, it is the 3D camera that adapts to the orientation of the platform.

[0066] In case there are two robotic arms, the two RGB-D 3D cameras are advantageously calibrated or normalized only with respect to the two robotic arms.

[0067] According to an embodiment, the platform comprises at least one plate or strip made of magnetic material or magnetized, extending along a longitudinal axis parallel to the axis of rotation and arranged on the receiving surface of the platform.

[0068] The magnetized strip makes it possible to attract the threads of the elastomeric element having magnetic properties, thereby pressing the end portion of said element onto the platform. Alternatively, provision can be made that the platform does not comprise such a magnetized strip.

[0069] According to a second aspect, the present invention relates to a method for automatically laying elastomeric elements in sequence by means of an apparatus for manufacturing a green tire, the apparatus being associated with a first orthogonal reference system and comprising a drum for manufacturing the green tire, a platform arranged upstream of the drum, at least one robotic arm arranged, and at least a first three-dimensional camera, the drum being capable of rotating about an axis, the platform extending along a transverse axis of the first reference system and comprising a flat receiving surface for receiving the end of the elastomeric element, the first three-dimensional camera generating a cloud of coordinate points measured in a reference system associated with the first camera, having a line of sight toward the platform and being configured to capture an image of the end portion of the elastomeric element on the platform (in particular on the flat receiving surface).

[0070] The robotic arm comprises at least one gripper associated with a second orthogonal reference frame different from the first reference frame and configured to grip an end portion of the elastomeric element from above.

[0071] The holder comprises at least three rows of magnetic elements or magnets which are parallel to each other and regularly spaced apart from each other along the axis of extension of the second reference system.

[0072] The method comprises at least one laying step, said laying step comprising a procedure having at least the following steps:

[0073] - a step of clamping the end portion of the elastomeric element, during which the clamping points of the clamp are determined based on the point cloud generated by the first camera, and

[0074] - a step of anchoring said end portions on the outer surface of the drum, during which the anchoring points of each row of magnetic elements on the outer surface of the drum are determined.

[0075] Thus, in the anchoring step, contact pressure is applied and the portion of the end portion anchored on the drum is gradually released.

[0076] For example, the end portion extends along an extension axis of the second reference system, which extension axis is angularly offset from the transverse axis of the first reference system.

[0077] Advantageously, the step of clamping the end portion of the elastomeric element includes: a step of acquiring an image of the end portion of the elastomeric element on the platform by a first camera, a step of dividing the image of the end portion of the elastomeric element on the platform into three areas, a step of determining the position of the clamper (especially the position of the initial clamping point) in the point cloud of the image acquired in the acquisition step by a processor, a step of correcting the initial clamping point by translating the initial clamping point along an extension axis of a second reference system and along a second longitudinal axis perpendicular to the extension axis of the second reference system parallel to the rotation axis and the transverse axis to obtain a clamping point, and a step of transmitting the clamping point to the robotic arm so that the end portion of the elastomeric element is clamped by the clamper.

[0078] Advantageously, the anchoring step comprises a step of causing the laser to project and a step of acquiring an image of the paving surface on the outer surface of the drum by means of a second camera (e.g. an RGB-D sensor), said second camera generating a cloud of coordinate points measured in a reference system associated with said second camera and having a line of sight towards the drum, said steps of causing the laser to project and of acquiring the image being carried out before the step of clamping the end portion of the elastomeric element by the clamper.

[0079] The lasers include a first fixed vertical laser that indicates the center of the drum, a second fixed horizontal laser that indicates the azimuth of the laying of the elastomeric element, and two variable vertical side lasers that indicate the longitude of the laying to predict the trajectory of the robot arm and confirm where to anchor the end.

[0080] For example, the anchoring step further includes:

[0081] - a step of processing the image of the paved area, during which the lasers and the point cloud generated by the second camera are detected, the pixels associated with the lasers are separated in the image acquired in the acquisition step, and then the intersection pixels at the intersection between the second horizontal laser and one of the side lasers are detected,

[0082] - a step of determining the anchor point of each row of magnets relative to the point of intersection in the plane normal to the plane of the normal to which the circle fitted on the point cloud of one lateral laser lies, based on the distance between the two rows of magnets and the radius of the magnets of the holder, and

[0083] - A step of transmitting the anchor point of each magnet to a control module for controlling the gripper, said control module being configured to control the rows of magnets of the gripper, in particular the actuator of each magnet, respectively.

[0084] Advantageously, before the laying step, the method comprises an elastomeric element supplying step of laying an end portion of the elastomeric element on the surface of the platform of the device.

[0085] According to an embodiment, the procedure of the laying step further comprises the steps of supporting the elastomeric element around the drum, cutting the elastomeric element into desired lengths, and welding the cut portions of the elastomeric element to end portions anchored on the outer surface of the drum. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Other objects, features and advantages of the present invention will become apparent from a reading of the following description given by way of non-limiting example only with reference to the accompanying drawings, in which:

[0087] [ Figure 1 ] shows very schematically an overall view of a green tyre manufacturing plant for carrying out the method for manufacturing a green tyre according to the invention;

[0088] [ Figure 2A ]、[ Figure 2B ]and[ Figure 2C ] shows in detail the end portion of the elastomeric element Figure 1 The location of the device on the platform;

[0089] [ Figure 3A ]、[ Figure 3B ]and[ Figure 3C ] shows various angular positions of the end portion of the elastomeric element relative to the transverse axis;

[0090] [ Figure 3D ] shows Figure 3B Details;

[0091] [ Figure 4 ] partially shows Figure 1 A holder for the device;

[0092] [ Figure 5 ] shows that Figure 1 The image processor of the device performs image processing;

[0093] [ Figure 6 ] schematically shows a three-dimensional representation from a first RGB-D camera;

[0094] [ Figure 7 ] shows the translation of the clamping point of the end portion of the elastomeric element according to the radius of the magnet of the clamp;

[0095] [ Figure 8 ] schematically shows Figure 1 an image captured by a second camera of an outer surface of a drum in the apparatus;

[0096] [ Figure 9 ] shows the anchor points P1, P2, P3 of the magnets of the clamper on the normal In the plane Pi(π) relative to the intersection point P I location;

[0097] [ Figure 10A ] shows a circle fitted on the point cloud of the laser;

[0098] [ Figure 10B ] shows the anchoring points of the magnets of the gripper;

[0099] [ Figure 11 ] shows an example of a pneumatic diagram for controlling an actuator of a magnet in a gripper;

[0100] [ Figure 12A ]、[ Figure 12B ] shows an elastomeric element wrapped around a drum in a 360° rotation;

[0101] [ Figure 13A ]、[ Figure 13B ]、[ Figure 13C ]、[ Figure 13D ] shows the successive steps of cutting an elastomeric element;

[0102] [ Figure 14A ] shows the exit point P of the cut portion when the elastomeric element is cut S and the surface on which it is wound upon the surface of the drum;

[0103] [ Figure 14B ] shows the position of the elastomeric element at the end of anchoring of its end portion on the drum;

[0104] [ Figure 14C ] shows a region of interest ROI where an entry point is formed during cutting;

[0105] [ Figure 15A ] schematically shows the initial point of interest P I,i and the final point of interest P F,i ;

[0106] [ Figure 15B ]yes Figure 15A Details;

[0107] [ Figure 15C ] shows the rotation angle for supporting the elastomer element

[0108] [ Figure 16 ] is a flow chart showing some steps in the method for manufacturing a green tire according to the present invention. DETAILED DESCRIPTION

[0109] In the remainder of this description, a first orthogonal reference system or datum X, Y, Z is considered, associated with the apparatus 10 for manufacturing a green tyre and comprising:

[0110] - a longitudinal axis X, which Figure 1 is horizontal, extends from rear to front and is parallel to the axis of rotation XX' of the drum 16;

[0111] - transverse axis Y, which is Figure 1 is horizontal, perpendicular to the longitudinal axis X, and extends from left to right; and

[0112] - vertical axis Z, which is Figure 1 The center is perpendicular to the longitudinal axis X and the transverse axis Y, and extends from bottom to top.

[0113] Considered is also a second orthogonal reference system or datum X, Y, Z, associated with the tool, in particular with the holder 25 used, and comprising:

[0114] - longitudinal axis X1, which is Figure 7 The middle is horizontal and extends from left to right;

[0115] - Extension axis Y1, which is Figure 7 is horizontal, perpendicular to the longitudinal axis X1 of the holder reference system, and extends from bottom to top; and

[0116] - vertical axis Z1, which is Figure 7 Orthogonal to the longitudinal axis X and the extension axis Y1 and extending from the rear to the front, said vertical axis Z1 coincides with the vertical axis Z of the reference system associated with the device.

[0117] Figure 1 A plant 10 for manufacturing a green tyre is shown, comprising a feed station 12 for supplying elastomeric elements 13 and at least one laying station 14 for laying said elements.

[0118] The term "elastomeric element" means an elastomeric product which has been optionally reinforced, calendered or extruded to a given profile, thereby forming a continuous strip or ply and, in a broader sense, a group of preassembled elastomeric elements. In this case, the elastomeric element 13 is wound on a reel 15.

[0119] The laying station 14 comprises a green tyre building drum 16 (partially shown), a robot arm 18 provided with actuators 20 or tools suitable for the steps of building a green tyre and a platform 21 for presenting the product.

[0120] The term "laying station" also means the area where the elastomeric elements are laid.

[0121] As shown, without being limiting in any way, the feed station 12 for supplying elastomeric elements 13 comprises a multi-axis industrial robot 34 suitable for manipulating containers holding the elastomeric elements.

[0122] The term "feeding station" also refers to the area where the industrial robot 34 is located. The feeding station 12 is adjacent to the laying station 14 and comprises a storage space 36 where the containers are placed.

[0123] For example, the container is in the form of a reel 15, a pay-off reel 38 comprising the reel 15 or a roller table holding an elastomeric element that does not fit on the reel.

[0124] The manufacturing facility 10 includes an electronic control unit 40 (ECU) configured to operate the feed station 12 and the layup station 14 .

[0125] The ECU 40 is particularly suitable for controlling the automatic laying of the elastomeric element 13 on the drum 16 .

[0126] The drum 16 has a substantially right cylindrical shape, which is rotationally symmetrical about a central axis XX'. The drum 16 is rotatable about the central axis XX' relative to a support 24, which is fixed or movable in a horizontal plane, for example by a carriage 23, or in multiple directions, for example by a multi-axis industrial robot.

[0127] The radially outer surface 16a of the drum 16 constitutes a laying surface in contact with the one or more first laying elements 13. The one or more second laying elements are in contact with the radially outer surface of the one or more first laying elements.

[0128] The robot arm 18 can be a six-axis type, comprising a series of six sections of variable length, articulated to one another via six joints or pivots, which is by no means limiting. For example, the robot includes a base 18a pivotally mounted on a fixed structure or gantry 28 via a first joint (not visible), a first segment or shoulder 18b pivotally movable relative to the base 18a via a second joint 26, a second segment or elbow 18c pivotally movable relative to the first segment 18b via a third joint 26a, and a wrist 18d pivotally movable relative to the second segment 18c along three different rotational axes via three joints (not visible). The base 18a and wrist 18d can rotate on their own. Each joint or pivot is actuated by an electric motor (not shown). One or more grippers 20 are integrally mounted to the wrist 18d. Depending on the tools used and the arrangement of the laying station 14, the robot arm 18 can take various forms with more or fewer axes of movement.

[0129] The robotic arm 18 is configured to perform an automated and sequential laying of the elastomeric elements 13 on the drum 16 .

[0130] For both the gripping step and the anchoring step, a single robotic arm is required.

[0131] As described below, the end portion 13a of the elastomeric element has a triangular shape oriented in either direction.

[0132] Thus, the apparatus may comprise a second robotic arm, identical and parallel to the first. The presence of the second robotic arm makes it possible to grip the end of the end portion 13a of the elastomeric element 13 oriented in the second direction. The second robotic arm may also be used in the cutting step to hold the end portion against the drum.

[0133] Typically, the apparatus may include one or two robotic arms 18 .

[0134] The tool 20 for performing automatic laying is selected from the group consisting of at least one gripper 25 and a pair of scissors. Figure 4 and Figure 7 The holder 25 will be described in detail.

[0135] The tool 20 may also comprise rollers for applying pressure to the element after it has been laid on the outer surface 16a of the drum 16 and pressing it against said outer surface 16a.

[0136] As shown, the apparatus 10 comprises a robotic arm 18 that projects above the drum 16 , preferably about 0.5 m from the central axis XX′ of the drum 16 in the horizontal direction.

[0137] As in Figure 2AAs shown in detail, a platform 21 for presenting the products is arranged upstream of the drum 16 and upstream of the mechanical guide GM.

[0138] The platform 21 comprises a flat receiving surface 21 a for receiving the end portion 13 a of the elastomeric element 13 , in particular the end portion 13 a of said element 13 after being partially unwound from the reel 15 .

[0139] The mechanical reinforcement of the elastomeric element 13, coupled with the fact that said element is wound on a reel 15, results in the surface of the end portion 13a, after being unwound onto the platform 21 for laying on the outer surface 16a of the drum 16, not being perfectly flat, as in Figure 2B Visible in.

[0140] To this end, the platform 21 may comprise a plate or strip 21 b made of magnetic material or magnetized, said plate or strip 21 b extending along the longitudinal axis X and arranged on a receiving surface 21 a for receiving the elastomeric element 13. The magnets 21 b make it possible to attract the magnetic threads of the elastomeric element 13, thereby pressing the end portion 13 of said element 13 against the platform 21. Alternatively, provision may be made for the platform 21 to comprise no such magnets 21 b.

[0141] The stiffness of the elastomeric element 13 may affect the position at which its end portion is unwound on the flat surface 21 a of the platform 21. In other words, the longitudinal position of the end portion 13 a of the unwound elastomeric element 13 may extend along an extension axis Y1 that may be angularly offset from the transverse axis Y perpendicular to the axis of rotation XX′ of the drum 16.

[0142] Figure 3A A situation is shown in which the end portion 13a of the unwound elastomeric element 13 extends along an axis of extension Y1 which is not angularly offset from the transverse axis Y perpendicular to the axis of rotation XX' of the drum 16. This situation is particularly rare.

[0143] Figure 3B The end portion 13a of the unwound elastomeric element 13 is shown extending along an extension axis Y1 angularly offset inwardly from the transverse axis Y, while Figure 3C The case is shown where the end portion 13a of the unwound elastomeric element 13 extends along an extension axis Y1 angularly offset outwards from the transverse axis Y.

[0144] exist Figure 4 and Figure 7 The holder 25 shown in detail in 2 comprises three rows of magnetic elements or magnets 25a, 25b, 25c, 25e, 25f parallel to each other and to the axis of rotation of the drum 16. The rows of magnetic elements are regularly spaced apart from each other in the direction of extension Y1.

[0145] As shown, the first and second rows of magnetic elements each include one magnetic element 25a, 25b, and the third row includes three magnetic elements 25c, 25e, 25f. One of the magnetic elements 25c of the third row is aligned with the magnetic elements 25a, 25b of the first and second rows along the extension axis Y1'.

[0146] In this case, the set of magnetic elements 25a, 25b, 25c, 25e, 25f is arranged to form a T. Typically, the shape of the holder is symmetrical.

[0147] By means of a T-shaped arrangement of the magnets or a symmetrical arrangement of the clamps, the same clamp can be used to clamp the end portion of the elastomeric element facing to the right or the end portion of the elastomeric element facing to the left.

[0148] Alternatively, provision can be made for the third row to comprise only one magnetic element.

[0149] As shown, the holder 25 includes five magnetic elements.

[0150] Alternatively, provision can be made for the holder 25 to include a different number of magnetic elements, for example greater than or equal to six magnetic elements.

[0151] The magnetic elements 25 a , 25 b , 25 c , 25 e , 25 f are mounted on a bracket 25 d that is configured to be connected to an end portion of one of the robotic arms 18 .

[0152] The gripper 25 of the robot arm 18 is configured to grip the end portion 13 a of the elastomeric element 13 from above.

[0153] However, since the holder 25 is rigid, if the end portion is moved along Figure 3B or Figure 3C If the extension axis Y1 shown extends angularly offset from the transverse axis Y, it would not be possible to align the clamp 25 with the end portion 13 a of the elastomeric element 13 .

[0154] The apparatus 10 includes a first 3D camera (not shown), such as an RGB-D sensor, which generates a coordinate point cloud measured in a reference frame associated with the first camera, has a line of sight toward the platform 21, and is configured to acquire an image of the end portion 13a of the elastomeric element 13 on the platform 21. This step corresponds to step 151 of acquiring an image of the elastomeric element 13 on the platform 21. The first 3D camera is attached to the gantry 28 and is directed upstream toward the platform 21.

[0155] The first 3D camera makes it possible to avoid the recalibration required when using a 2D camera. Specifically, the first 3D camera can immediately match the distance of an object and its perceived size, thereby making it possible to measure the size of an object without having to indicate the depth of the object relative to the camera.

[0156] To this end, the electronic control unit ECU 40 includes a clamping module 50 for clamping the end portion 13 a of the elastomeric element 13 .

[0157] The clamping module 50 includes a capturing module 51 for capturing an image of the end portion 13 a of the elastomeric element 13 on the platform 21 through a first 3D camera.

[0158] The clamping module 50 further includes a segmentation module 52 for segmenting the image of the end portion 13a of the elastomeric element 13 on the platform 21 into Figure 3B There are three visible areas Z1, Z2, and Z3.

[0159] The first zone Z1 corresponds to Figure 3D The tip P of the end portion 13a is visible in po The total length L of the end portion 13a of the element 13 corresponds to the tip P of the end portion 13a. po The distance from the edge 21c of the platform 21.

[0160] Preferably, the first zone Z1 and the third zone Z3 each correspond to 30% of the total length L. Alternatively, the length of the first zone Z1 may be different from the length of the third zone Z3. For example, the length of the first zone Z1 may be between 20% and 30% of the total length L, and the length of the third zone Z3 may be between 20% and 30% of the total length L.

[0161] The clamping module 50 further includes a determination module 53 for determining the position of the clamp 25, in particular the clamping point P of the clamp 25. p location.

[0162] The determination module 53 for determining the position of the gripper 25 is configured to determine a straight line d1 passing through a side edge of the second zone Z2 .

[0163] Clamping point P p In the axial direction, the tip P of the end portion 13a is po Offset distance d p .

[0164] The determination module 53 for determining the position of the gripper 25 further comprises a first image processor configured to determine the tip or initial gripping point P pi Initial position in the point cloud of the image from the acquisition module 51 .

[0165] The image processor includes the following steps, refer to Figure 5 As shown, where the reference frames u and v are specific to the image. The processor detects the area of ​​the platform 21 in the image and then performs a binary thresholding process in the area. The binary thresholding process can be performed using the so-called Otsu's method.

[0166] In the binary image obtained, the maximum contour C is detected and the extreme pixels P corresponding to the left, right and bottom of the contour are extracted. max,g 、P max,d and P max,b .

[0167] Then, the orientation of the end portion 13a of the elastic member 13 is determined using these three pixels. max,g and the bottom extreme pixel P max,b The first distance between the right extreme pixel P max,d and the bottom extreme pixel P max,b If the first distance is greater than the second distance, that is, if ||P max,g -P max,b ||>||P max,d -P max,b ||, then it is the elastic element facing the left, otherwise it is the elastic element facing the right.

[0168] Finally, the pixel p of the right edge of the end portion 13a is detected by searching for the intersections between the N vertical lines and the contour C of the second area Z2 of the end portion 13a of the elastomeric element 13. d,i and the pixel p on the left edge g, i.

[0169] The first camera of RGB-D type further makes it possible to obtain a depth frame superimposed on the color image in order to retrieve the depth of the points of interest obtained from the image processing performed on the color image and then calculate the three-dimensional coordinates of each of said points to obtain the depth as shown in FIG. Figure 6 Thus, for each pixel of the acquired image, its depth and then its spatial coordinates can be retrieved.

[0170] The first image processor is configured to estimate the pixel P max,b Obtained tip P po 3D points and pixels p g,i and pd,i Obtained left 3D point P g,i and the right 3D point P d,i .

[0171] The first image processor is configured to estimate the number of pixels passing through these points P g,i and P d,i The straight lines d2 and d3 are used to calculate the angle θ formed between the two straight lines d2 and d3. NST , and by putting point P po Project to obtain the initial clamping point P pi , the point P po It is projected onto the plane defined by the two straight lines d2 and d3.

[0172] The projected distance between these points corresponds to the distance d mentioned above p .

[0173] Then, the first image processor is configured to convert the initial gripping point P pi The distance Ra is translated along the longitudinal axis X1 and the extension axis Y1 of the second reference system X1, Y1, Z1 associated with the clamp 25, that is, the distance Ra is translated to the left and backward when the elastomeric element 13 is facing to the right, or the distance Ra is translated to the right and backward when the elastomeric element 13 is facing to the left.

[0174] Figure 7 The initial gripping point P is shown with the elastomeric element 13 facing to the right. pi The distance Ra is translated to the left and back, thereby obtaining the gripping point P transmitted to the robot arm 18 by the transmission module 54. pf .

[0175] The distance Ra corresponds to the radius of the magnets 25 a , 25 b , 25 c of the holder 25 .

[0176] This translation distance Ra along the longitudinal axis X1 of the second reference system X1 , Y1 , Z1 makes it possible to increase the surface area of ​​the holder 25 available for magnetization together with the end portion 13 a of the elastomeric element 13 .

[0177] Specifically, the clamp 25 is initially aligned with the line d1, is displaced by a distance -Ra along the longitudinal axis X1 of the second reference system when clamping the end portion 13a of the elastomeric element 13, and is displaced by a distance +Ra along the longitudinal axis X1 to offset this displacement when laying.

[0178] A similar procedure is followed along the extension axis Y1 of the second reference system X1 , Y1 , Z1 .

[0179] The electronic control unit ECU 40 further comprises an anchoring module 60 for anchoring said end portion 13 a on the outer surface 16 a of the drum 16 .

[0180] When the end portion 13 a of the elastomeric element 13 has been gripped by the gripper 25 , it needs to be moved to the drum 16 and anchored on the outer surface 16 a of said drum 16 .

[0181] To this end, the surface of the end portion 13a is rolled onto the outer surface 16a of the drum 16 by applying contact pressure and gradually releasing the anchoring portion of the end portion 13a.

[0182] Since the clamp 25 is rigid, it is not possible to anchor the end portion 13a to the drum 16 in a single laying operation. Since the clamp 25 comprises three rows of magnets 25a, 25b, 25c, 25e, 25f, the anchoring step is performed in three successive laying operations. T1 、R T2 and R T3 That is, each row of magnets 25a, 25b, 25c, 25e, 25f performs a laying operation.

[0183] To determine these laying instructions R T1 、R T2 and R T3 The anchoring module 60 includes a laser projection module 61 for projecting lasers, namely a first fixed red vertical laser L1 (which indicates the center of the drum 16), a second fixed green horizontal laser L2 (which indicates the azimuth of the laying of the elastomeric element) and two variable green vertical side lasers L3, L4 (which indicate the longitude of the laying) on ​​the outer surface 16a of the drum 16.

[0184] Lasers L3 and L4 with wavelengths corresponding to green are preferred because green can be more easily distinguished from the tire's rubber. Rubber tends to reflect red, which reduces the contrast of the lasers. Alternatively, lasers L3 and L4 can be configured with wavelengths corresponding to red or another color.

[0185] Similarly, lasers L1 and L2 may have wavelengths corresponding to a color other than red, such as green or another color.

[0186] The laser is attached to the gantry 28 .

[0187] The apparatus 10 further comprises a second 3D camera (not shown) generating a coordinate point cloud measured in a reference frame associated with the second camera, having a line of sight towards the drum 16 and configured to acquire images of the paving area on the outer surface 16a of the drum 16 .

[0188] The second camera is, for example, an RGB-D sensor.

[0189] The second camera is set to highlight the various lasers L1, L2, L3, L4. As a non-limiting example, the second camera can be set to increase exposure to capture light from the lasers, increase saturation to highlight the primary colors, and modify white balance to highlight green.

[0190] The anchoring module 60 includes a capture module 62 for capturing images of the outer surface 16a of the drum 16, in particular, images of the laying area, by means of a second camera attached to the gantry 28 and directed toward the drum 16. The captured images of the outer surface 16a of the drum 16 are shown in FIG. Figure 8 middle.

[0191] Before the end portion 13a of the elastomeric element 13 is gripped by the gripper 25, an image of the laying area on the outer surface 16a of the drum 16 is acquired in order to predict the trajectory of the robot arm 18 and to identify where to anchor said end 13a.

[0192] This collection step is carried out upstream of the end portion 13a of the clamping elastomeric element 13, making it possible to avoid creeping of said end 13a.

[0193] The anchoring module 60 further includes an image processing module 63 for processing the image of the paving area, the image processing module 63 including a second image processor configured to detect the lasers L1 , L2 , L3 , L4 and the 3D point cloud.

[0194] The image processing module 63 is further configured to separate pixels associated with the lasers in the acquired image using color segmentation in an image converted into a saturated image (referred to as hue, saturation, value or HSV).

[0195] The module 63 is configured to detect an intersection pixel p at the intersection between the second horizontal laser L2 and one of the side lasers L3, L4 (i.e., the right side laser L3 if the end portion 13a of the elastomeric element 13 is facing right, or the left side laser L4 if the end portion 13a is facing left). i .

[0196] The axis XX' of the drum 16 is determined by the intersection pixel p I The middle pixel p of the drum detected at the intersection between the first vertical laser L1 and the second horizontal laser L2 m The vectors between are limited.

[0197] Using the depth information of the camera, we can estimate the intersection pixel p I and the middle pixel p of the drum mThe intersection point P corresponding to the three-dimensional point I and the middle point P m .

[0198] The anchoring module 60 comprises a module 64 configured to be fixed to the anchoring position according to the distance d between the two rows of magnets 25a, 25b, 25c, 25e, 25f. r and the radius R of magnets 25a, 25b, 25c, 25e, 25f a To determine the normal of each of magnets 25a, 25b, 25c below In the plane Pi(π) relative to the intersection point P I Anchor points P1, P2, P3: Figure 8 The plane of the normal line on which the circle C fitted on the point cloud of one of the side lasers L3 and L4 lies.

[0199] Figure 9 Shows how the normal In the plane Pi(π) relative to the intersection point P I To locate the anchor points P1, P2, P3 of each row of magnets 25a, 25b, 25c, 25e, 25f.

[0200] To determine the position of the first anchor point of the first row of magnets 25a on the fitted circle C, the intersection point PI is pivoted around the axis of the circle by an angle θ according to the following equation I1 :

[0201] [Equation 1]

[0202] θ I1 =R a / R

[0203] Where R is the measured radius of the drum 16 .

[0204] The positions of the second anchor point P2 and the third anchor point P3 of the second row of magnets 25b and the third row of magnets 25c on the fitting circle C are as follows: I The angle θ around the axis of the circle is respectively pivoted according to the following equation I2 and θ I3 To limit:

[0205] [Equation 2]

[0206] θ I2 =(R a +d r ) / R

[0207] [Equation 3]

[0208] θ I3 =(R a +2dr ) / R),

[0209] Center P c The fitting circle C with radius R is determined based on the drum axis, the drum radius and the center of the circle.

[0210] The axis of the drum passes through the vector To determine the radius, the radius can be obtained in two ways: by measuring it with a telemeter or by estimating the diameter.

[0211] In order to determine the center P c The module 64 is configured to fit a circle on the 3D point cloud of one of the side lasers L3, L4. The equation sought is from The axis of the drum is derived from the great circle C of the drum (in other words, the circle drawn on the sphere with the same center as the sphere). In other words, the axis of the drum is the normal to the intersection of a sphere with the same radius as the drum 16 and a plane passing through the center of the sphere.

[0212] P i For any point on the sphere, we get the first relation:

[0213] [Equation 4]

[0214] (x i -x c ) 2 +(y i -y c ) 2 +(z i -z c ) 2 -R 2 =0

[0215] The great circle lies on the normal In the plane π, for any point P i The following relationship is obtained:

[0216] [Equation 5]

[0217]

[0218] Expanding this gives the following equation:

[0219] [Equation 6]

[0220] n π,x (x c -x i )+n π,y (y c -y i )+n π,z (z c -z i )=0

[0221] By setting the radius R and normal Finally found point P c , so that for any intersection point P I , the following equations are solved numerically:

[0222] [Equation 7]

[0223] ((x i -x c ) 2 +(y i -y c ) 2 +(z i -z c ) 2 -R 2 ) 2

[0224] +(n π,x (x c -x i )+n π,y (y c -y i )+n π,z (z c -z i )) 2 =0

[0225] Once the circle C is defined, it is necessary to work in two dimensions to perform various rotations about the circle.

[0226] Figure 10A The circle C fitted on the point cloud of the laser is shown. The intersection point P I Projection P on the fitted circle C I / C Rotate around the center of the circle to find the anchor points P1, P2, P3 of each magnet 25a, 25b, 25c. This projection is necessary to ensure that all points are on the fitted circle C. The vectors of the anchor points P1, P2, P3 are determined using the following relationship and

[0227] and

[0228] Therefore, the vector is defined as the vector product of these vectors, i.e.

[0229] The second anchor point P of the second row of magnets 25b 2,TCP is by placing the second intersection point P2 along the axis Translation distance d r To determine, such as Figure 10B shown.

[0230] Likewise, the third anchor point P of the third row of magnets 25c, 25e, 25f 3,TCP is by placing the third intersection point P2 along the axis Translation distance 2d r to confirm.

[0231] Therefore, the gripper 25 follows the reference frame Then The end portion 13a of the elastomeric element 13 is anchored to the third point P3, then to the second point P2, and finally to the first point P1 in this order.

[0232] Figure 10B Shows the reference frame used to obtain and displacement.

[0233] In order to Go to Then from Go to Ideally, the robot arm 18 should follow a trajectory that is an involute of a circle in order to roll the surface of the end portion 13a of the elastomeric element 13 onto the surface 16a of the drum 16 by applying contact pressure. However, considering the flexibility of the end portion 13a of the elastomeric element 13 and the short distances between the various anchor points, it can be assumed that an approximation of such an involute is sufficient. In short, the robot arm 18 follows a linear trajectory between each anchor point, and only the three calculated anchor points are transmitted to the arm 18.

[0234] The module 64 for determining the anchoring point is configured to convert the displacement d previously determined when clamping the end portion 13a of the elastomeric element 13 into p and R a Take it into consideration.

[0235] Therefore, the three anchor points P 1,TCP 、P 2,TCP 、P 3,TCP Displacement radius along the longitudinal axis X - R a To compensate for the translation of the entire gripper 25, the first anchor point P 1,TCP Displacement distance d along the longitudinal axis X p This compensates for the displacement performed relative to the tip of the end portion 13a, thereby ultimately obtaining the respective anchoring points P1, P2, P3 of the magnets 25a, 25b, 25c.

[0236] The anchor points P1 , P2 , P3 of each row of magnets 25 a , 25 b , 25 c , 25 e , 25 f are then transmitted to the control module 65 for controlling the gripper 25 .

[0237] The gripper control module 65 is configured to control the magnets 25a, 25b, 25c of the gripper 25, respectively, and in particular an actuator (not shown) of each magnet.

[0238] In particular, when anchoring the end portion 13 a of the elastomeric element 13 on the drum 16 , the actuators must be deactivated row by row in order to release the anchoring zone of the elastomeric element 13 .

[0239] Figure 11 An example of a pneumatic diagram for controlling the actuators of the rows of magnets 25a, 25b, 25c, 25e, 25f in the gripper 25 is shown. The second and third actuators are each connected to a secondary pneumatic directional valve 26a, 26b, for example of the 5 / 2 type, which is connected to a main pneumatic directional valve 26c, for example of the 5 / 3 type. The first actuator of the first magnet 26a is directly connected to the main pneumatic directional valve 26c.

[0240] The anchoring module 60 makes it possible to anchor a product of complex shape on a circular shape, ie a drum, by determining three anchoring points belonging to the same circle.

[0241] The ECU 40 further comprises a support module 70 configured to wind the elastomeric element 13 around the drum 16 in a 360° rotation once the end portion 13a of the element 13 is anchored on the outer surface 16a of the drum 16, as shown in FIG. Figure 12A and Figure 12B shown.

[0242] The ECU further comprises a cutting module 80 configured to cut the elastomeric element 13 wound on the drum 16 into desired lengths.

[0243] The metal fiber reinforced elastomeric element 13 must be cut between and along two metal fibers.

[0244] The cutting module 80 is configured to transmit instructions to a robot arm 18 to cut the inc Insert the cutting tool between the two wires and cut until the exit point P S , return to the entry point P inc , and then cut the remaining portion of the elastomeric element 13 until the end point P F ,like Figure 13A 、 Figure 13B 、 Figure 13C and Figure 13D shown.

[0245] By synchronizing the rotation of the robot arm 18 with the drum 16, the remaining portion of the elastomeric element 13 is cut until the end point PF .

[0246] The cutting module 80 includes a cutting preparation module 81, which is configured to determine the cutting point P inc .

[0247] Entry point P inc is determined upstream of the support operation.

[0248] When the elastomeric element 13 is cut and its surface is rolled onto the surface of the drum 16, the exit point P of the cut portion S With the initial point of interest P I,i Overlap, such as Figure 14A The point of interest is located at the other end of the hypotenuse of the right triangle formed by the tip of the end portion 13 a of the elastomeric element 13 .

[0249] At the end of the anchoring of the end portion 13a of the elastomeric element 13 on the drum 16, the elastomeric element 13 is located Figure 14B Position shown.

[0250] The cutting preparation module 81 is configured to arrange the entry point in a manually defined region of interest ROI selected between the mechanical guide GM downstream of the platform 21 and the top of the drum 16 so that the cutting tool has enough space to cut into the elastomeric element 13 .

[0251] exist Figure 14C In the example, the region of interest ROI is located at a known azimuth angle A1, which is itself located at an angle β from the azimuth angle A2 of the horizontal laser L2, at which the elastomeric element 13 is anchored in the anchoring step. I,i The target distance from the guidance boundary is denoted as Δ g .

[0252] l NST is the width of the elastic element 13, L is the angle θ NST The length of the adjacent side, R is the radius of the drum 16, in order to make the initial point of interest P I,i Arranged at the azimuth angle A2 of the laser L2, the drum needs to be rotated by an angle γ L =L / R.

[0253] Therefore, in order to set the initial point of interest P I,i To be arranged in the region of interest ROI, the drum 16 needs to be rotated by an angle γ = L / R - β.

[0254] In order to detect the initial interest point P in the positioning area I,i, grazing incidence illumination is used to be able to distinguish the elastomeric element 13 from the underlying layer on the drum 16. This produces shadows along the edges of the elastomeric element 13 which define the outline in the image.

[0255] The cutting preparation module 81 includes an image processor 82 configured to determine an initial point of interest P I,i .

[0256] The input to the algorithm is the 3D image from the second camera pointed at the drum 16, the depth frame, and the pixels where the initial interest point P has been placed. I,i The mask of the region of interest (ROI).

[0257] To detect contours, the image processor 82 uses a Sobel filter (not shown) configured to detect horizontal intensity changes and then vertical intensity changes by convolution. By combining the results, the gradient of each point is obtained.

[0258] In the present case, only diagonal contours are sought, so the image processor 82 applies the Sobel filter twice with a 3x3 diagonal convolution matrix.

[0259] For the elastomeric element 13 facing left, the matrix is ​​represented as follows:

[0260]

[0261] For the elastomeric element 13 facing to the right, the matrix is ​​represented as follows:

[0262]

[0263] The use of a diagonal matrix is ​​optimal for elastomeric elements whose end portions 13a form an angle of 45° with the transverse axis Y. Another angle of the end portions 13a may be provided.

[0264] The image processor 82 is then configured to use a binarization thresholding method to obtain a resulting black and white image, and is configured to focus in the region of interest ROI to detect the largest contour of the image in order to separate it in the black and white image.

[0265] For each line of the image containing at least one white pixel, only the rightmost pixels (for the elastomeric element 13 towards the left) are retained in order to refine the contour as close as possible to the elastomeric element 13. The contour is then expanded towards the right using only the expansion function with the convolution vector k = [1, 1, 1, 1, 1, 0, 0, 0, 0, 0].

[0266] The image processor 82 is then configured to perform a new contour search and search the convex envelope of the contour for polygons having vertices represented by the pixels.

[0267] This step makes it possible to reduce the number of pixels of the contour, using only the vertices of the convex envelope. I Determined to be the lowest vertex of the two leftmost vertices.

[0268] During the cutting movement the cutting tool must not hit the mechanical guide or the drum 16. This is why the point of interest P I Need to be located at a distance Δ from the mechanical guide GM g± ∈ place.

[0269] To measure the distance Δ g± ∈, the image processor 82 uses pixel p dir , the pixel p dir is the highest vertex of the two leftmost vertices.

[0270] Line d NST is a 2D image consisting of two pixels p I and p g The defined straight line. Pixel p g Corresponding to the straight line d NST The line d that is manually defined in the image and represents the boundary of the mechanical guide g The intersection between.

[0271] From pixel p I and p g The point P obtained I,i and P g The distance between them is compared with the distance Δg. If the initial point of interest P I,i Too close to the mechanical guide GM, the actuator 20 is therefore at risk of being blocked by the mechanical guide GM, and if the initial point of interest P I,i Too far and there is a risk that the actuator 20 will be blocked by the drum 16 .

[0272] The image processor 82 displaces the elastic element 13 so that the pixel p I The initial point of interest P obtained I,i Located at a distance Δg, this is ideal for the plunging movement. The displacement is performed by rotating the drum 16, the direction of rotation of the drum 16 depending on the marking of the displacement to be performed.

[0273] For example, Δg=0.055m and ∈=0.01.

[0274] After the initial point of interest P is detected I,iAfterwards, and after verifying the distance Δg between this point and the mechanical guide GM, the elastomeric element 13 is supported by the supporting module 70 before the cutting operation is carried out, i.e. by winding it around the drum 16. This operation is carried out by synchronizing the rotation of the drum 16 with the rotation of the reel 15.

[0275] Once the elastomeric element 13 is supported, Figure 15A The initial point of interest P determined before the support operation I,i Different from the final point of interest P F,i , the final point of interest P F,i is a point of physical interest which forms part of the elastomeric element 13 and which therefore rotates about the drum 16 therewith.

[0276] The cutting module 80 includes a module 83 for cutting the initial point of interest P I,i Determine the entry point P inc And the entry point P inc and Figure 13A 、 Figure 13B 、 Figure 13C The desired exit point P for the cutting phase is shown S The constant distance h between 偏移 .

[0277] Constant distance h 偏移 It is predetermined in the previous step and will not be described here.

[0278] like Figure 15B As shown, the entry point P inc Along the axis XX' of the drum 16 from the initial point of interest P I,i Axially offset x 偏移 = sinθ NST ·h 偏移 .

[0279] Exit point P S With the initial point of interest P I,i The length between 偏移 As shown below:

[0280] l 偏移 =h 偏移 cosθ NST

[0281] Therefore, if Figure 15C As shown, the rotation angle for supporting the elastic element 13 Not 2π, but equal to in

[0282] Thus, when the elastomeric element 13 is attached to the drum 16, the exit point PS and the final point of interest P F,i coincide.

[0283] The cutting module 80 further includes a heating module 84 for heating a cutting tool (not shown).

[0284] The cutting module 80 further includes a module for analyzing the axial force F of the robot arm 18 generated during the cutting operation. x and lateral force F y Module 85, the module 85 is configured to obtain the force through the force sensor installed on the robot arm 18, determine the cutting exit point P S , and correct the angle of the cutting tool in real time during the cutting operation.

[0285] Finally, the ECU 40 comprises a welding module 90 configured to press the elastomeric element 13 as close as possible to the cutting portion and to control a multi-profile pressing roller capable of rolling in all directions and accompanying the elastomeric element 13 as the cutting proceeds.

[0286] The welding module 90 is also configured to control a welding tool, referred to as a zipper, that is configured to join the cut ends of the elastomeric element 13 together along a joint in a first direction and a second direction.

[0287] Figure 16 The flowchart in shows some manufacturing steps of a method 100 for manufacturing a green tire.

[0288] The method 100 includes a step 140 of sequentially laying up the elastomeric elements 13 using the manufacturing apparatus 10 .

[0289] To this end, the method 100 comprises, before the laying step 140 , a feeding step 110 of feeding the laying station 14 with the aid of the feed station 12 , the elastomeric element 13 , the element to be laid taking the form of a continuous strip or ply.

[0290] The feeding step 110 includes a step 111 of gripping a container (e.g., a reel 15, a pay-off drum 38 containing a reel 15, or a roller table) by a multi-axis industrial robot 34 or an automated carriage. Each container contains an elastomeric element to be laid. The feeding step 110 further includes a step 112 of positioning the container so that the elastomeric element is ready for laying and unwinding the elastomeric element 13 until its end 13a is laid on the surface 21a of the platform 21 of the apparatus 10.

[0291] The laying step 140 is automatically controlled by the ECU 40. A robot arm 18 provided with a gripper 25 automatically lays the elastomeric element 13 on the green tire building drum 16 according to the following procedure.

[0292] The laying step 140 includes a procedure having the following steps: a step 150 of clamping the end portion 13a of the elastomeric element 13, a step 160 of anchoring the end portion 13a on the outer surface 16a of the drum, a step 170 of supporting the elastomeric element 13 around the drum, a step 180 of cutting the elastomeric element 13 into the desired length, and a step 190 of welding the cut portion of the elastomeric element to the anchored end portion 13a.

[0293] The step 150 of clamping the end portion 13 a of the elastomeric element 13 includes a step 151 of acquiring an image of the end portion 13 a of the elastomeric element 13 on the platform 21 by a first RGB-D camera.

[0294] The clamping step 150 further comprises a step 152 of segmenting the image of the end portion 13a of the elastomeric element 13 on the platform 21 into three zones Z1 , Z2 , Z3 as described above with reference to the segmentation module 52 for segmenting the image of the end portion 13a .

[0295] The clamping step 150 comprises the following step 153: determining the position of the clamp 25, in particular the clamping point P, by means of an image processor. p , as described above with reference to the determination module 53 for determining the position of the gripper 25 .

[0296] The clamping step 150 comprises the following step 154: by means of an image processor, the initial clamping point P pi The initial gripping point P is corrected by translating the distance Ra along the longitudinal axis X1 and the extension axis Y1 of the reference system of the gripper 25. pi To obtain the clamping point P pf , as described above with reference to the determination module 53 for determining the position of the gripper 25 .

[0297] Then, in the transfer step 155, the clamping point P pf Transmitted to the robotic arm 18.

[0298] In the step 160 of anchoring said end portion 13a on the outer surface 16a of the drum 16, contact pressure is applied and the anchoring of the end portion 13a is gradually released.

[0299] The anchoring step 160 includes a step 161 of projecting a laser and a step 162 of acquiring an image of the outer surface 16 a of the drum 16 by a second RGB-D camera directed toward the drum 16 .

[0300] Steps 161 and 162 are performed before step 155 of gripping the end portion 13 a of the elastomeric element 13 by the gripper 25 in order to predict the trajectory of the robot arm 18 and to determine where to anchor said end portion 13 a.

[0301] The lasers comprise a first fixed vertical laser L1 , for example red, indicating the centre of the drum 16 , a second fixed horizontal laser L2, for example green, indicating the azimuth of the laying of the elastomeric element, and two variable vertical side lasers L3 , L4 , for example green, indicating the longitude of the laying.

[0302] The anchoring step 160 further comprises a step 163 of processing the image of the paving area, wherein the lasers L1, L2, L3, L4 and the 3D point cloud are detected, pixels associated with the lasers are separated in the acquired image, and an intersection pixel p is detected at the intersection between the second horizontal laser L2 and one of the side lasers L3, L4 (i.e., the right side laser L3 if the end portion 13a of the elastomeric element 13 is facing right, or the left side laser L4 if the end portion 13a is facing left). i The image processing module 63 is used to perform step 163 of processing the image.

[0303] The anchoring step 160 further comprises the following step 164: according to the distance d between the two rows of magnets 25a, 25b, 25c r and the radius R of the magnets 25a, 25b, 25c a To determine the normal of each row of magnets 25a, 25b, 25c, 25e, 25f in the following In the plane Pi(π) relative to the intersection point P i Anchor points P1, P2, P3: the plane of the normal on which the circle C fitted on the point cloud of one of the side lasers L3, L4 lies.

[0304] As described above, the reference anchor point determination module 64 determines the anchor points P1 , P2 , P3 of each row of magnets 25 a , 25 b , 25 c , 25 e , 25 f .

[0305] The anchoring step 160 further includes a step 165 of transmitting the anchoring points P1, P2, P3 of each row of magnets 25a, 25b, 25c, 25e, 25f to a control module 65 for controlling the clamp 25, wherein the control module 65 is configured to control the rows of magnets 25a, 25b, 25c, 25e, 25f of the clamp 25, in particular the actuators of each row of magnets.

[0306] In the supporting elastomeric element 13 around the drum step 170 , once the end portion 13a of the elastomeric element 13 is anchored on the outer surface 16a of the drum 16 , the elastomeric element 13 is wound around the drum 16 in a 360° rotation.

[0307] The step 180 of cutting the elastomeric element 13 to the desired length comprises a step 181 of preparation for cutting, wherein the entry point P corresponding to the insertion point of the cutting tool between the two metal wires is determined by means of the module 81 for preparation for cutting as described above. inc .

[0308] Upstream of the supporting step 170 a step 181 of preparing for cutting is performed.

[0309] In a step 181 of preparing for cutting, the region of interest ROI and the initial point of interest P are determined as described above with reference to the module 81 and the image processor 82 for preparing for cutting. I,i .

[0310] The cutting step 180 further includes the following step 183: I,i Determine the entry point P inc And the entry point P inc and Figure 13A 、 Figure 13B 、 Figure 13C The desired exit point P for the cutting phase is shown S The constant distance h between 偏移 , as mentioned above, is used to determine the entry point P inc As described in module 83.

[0311] The cutting step 180 further includes a step 184 of heating the cutting tool during the cutting operation 186 and analyzing the axial force F of the robot arm 18 generated during the cutting operation 186. x and lateral force F y Step 185 is configured to obtain the force through the force sensor installed on the robot arm 18 to determine the cutting exit point P S , and the angle of the cutting tool is corrected in real time during the cutting operation 186.

[0312] The step 190 of welding the cut portion of the elastomeric element to the anchored end portion 13a involves pressing the elastomeric element 13 as close as possible to the cut portion and controlling a multi-profile pressing roller that is able to roll in all directions and accompany the elastomeric element 13 as the cutting 186 is performed.

[0313] In a welding step 190 , a welding tool, known as a zipper, is controlled and configured to join the cut ends of the elastomeric element 13 together along a joint in a first direction and a second direction.

[0314] The laying system and method according to the present invention are designed to be suitable for existing manual equipment and new equipment.

Claims

1. An apparatus (10) for manufacturing a green tire, associated with a first orthogonal reference system (X, Y, Z) and comprising a drum (16) for manufacturing a green tire, a platform (21) arranged upstream of the drum (16), at least one robotic arm (18), an electronic control unit (40), and at least a first three-dimensional camera, the drum (16) being rotatable about an axis of rotation (XX') of the first reference system, the platform (21) extending along a transverse axis (Y) of the first reference system and comprising a flat receiving surface (21a) for receiving an end portion (13a) of an elastomeric element (13), the electronic control unit (40) being configured to operate the robotic arm (18), the at least first three-dimensional camera generating a cloud of coordinate points measured in a reference system associated with the first camera, having a line of sight towards the platform (21) and being configured to acquire an image of an end portion (13a) of the elastomeric element (13) on the platform (21), characterized in that: The robot arm (18) comprises at least one gripper (25), the gripper (25) being associated with a second orthogonal reference system (X1, Y1, Z1) different from the first reference system (X, Y, Z), being configured to grip the end portion (13a) of the elastomeric element (13) from above, and comprising at least three rows of magnetic elements (25a, 25b, 25c, 25e, 25f), the at least three rows of magnetic elements (25a, 25b, 25c, 25e, 25f) being parallel to each other and regularly spaced apart from each other along an axis of extension (Y1) of the second reference system (X1, Y1, Z1); the electronic control unit (40) comprising at least: a gripping module (50) for gripping the end portion (13a) of the elastomeric element (13) and configured to determine a gripping point (P) of the gripper (25) based on the point cloud generated by the first camera; p ),as well as - an anchoring module (60) for anchoring the end portion (13a) on the outer surface (16a) of the drum (16) and configured to determine an anchoring point (P1, P2, P3) of each row of magnetic elements (25a, 25b, 25c, 25e, 25f) on the outer surface (16a) of the drum (16).

2. The device (10) according to claim 1, wherein The end portion (13a) extends along an extension axis (Y1) of a second reference system (X1, Y1, Z1), said extension axis (Y1) being angularly offset from a transverse axis (Y) of the first reference system (X, Y, Z).

3. The device (10) according to claim 1 or 2, wherein The clamping module (50) comprises: - an acquisition module (51) for acquiring an image of the end portion (13a) of the elastomeric element (13) on the platform (21) by means of a first camera, - a segmentation module (52) for segmenting the image of the end portion (13a) of the elastomeric element (13) on the platform (21) into three zones (Z1, Z2, Z3), and - a determination module (53) for determining the clamping point (P p ), and comprising a first image processor configured to: determine an initial gripping point (P pi ), by moving the initial clamping point (P) along the extension axis (Y1) of the second reference system (X1, Y1, Z1) and along the second longitudinal axis (X1) perpendicular to the extension axis (Y1) of the second reference system pi ) is translated by a distance (Ra) corresponding to the radius of the magnetic elements (25a, 25b, 25c, 25e, 25f) of the clamper (25) to correct the initial clamping point (P pi ), and determine the gripping point (P) transmitted by the transmission module (54) to the robot arm (18) pf ).

4. The apparatus (10) according to any one of the preceding claims, comprising a first fixed vertical laser (L1) indicating the center of the drum (16), a second fixed horizontal laser (L2) indicating the azimuth of the laying of the elastomeric element, and two variable vertical lateral lasers (L3, L4) indicating the longitude of the laying, the lasers being rigidly fixed to the fixed structure (28) of the apparatus, wherein The anchoring module (60) comprises a module (61) for projecting the lasers (L1, L2, L3, L4) onto the outer surface (16a) of the drum (16).

5. The apparatus (10) of claim 4, comprising a second three-dimensional camera generating a cloud of coordinate points measured in a reference frame associated with the second camera, having a line of sight towards the drum (16) and configured to acquire images of a paving area on an outer surface (16a) of the drum (16), wherein The anchoring module (60) comprises: - an acquisition module (62) for acquiring images of the paving area, and - a module (63) for processing an image of the paved area, comprising a second image processor configured to detect the lasers (L1, L2, L3, L4) and intersection pixels (p) at the intersection between a second horizontal laser (L2) and one of the side lasers (L3, L4); I ), and estimate the intersection pixel (p I ) and the middle pixel of the drum (p m ) of the three-dimensional point corresponding to the intersection point (P I ) and the midpoint (P m ).

6. The device (10) according to any one of the preceding claims, wherein The electronic control unit (40) further comprises a supporting module (170) for supporting the elastomeric element (13) around the drum (16), a cutting module (180) for cutting the elastomeric element (13) into a desired length, and a welding module (190) for welding the cut portion of the elastomeric element (13) to an end portion (13a) anchored on the outer surface (16a) of the drum (16).

7. The device (10) according to any one of the preceding claims, wherein The gripper (25) of the robotic arm (18) includes actuators, each of which is connected to a magnetic element (25a, 25b, 25c, 25e, 25f), and the actuators are controlled to release the third row of magnetic elements (25c, 25e, 25f), the second row of magnetic elements (25b), and then the first row of magnetic elements (25a) in sequence.

8. The device (10) according to any one of the preceding claims, wherein The magnetic elements (25a, 25b, 25c, 25e, 25f) of the gripper (25) of the robot arm (18) are mounted on a bracket (25d) configured to be connected to an end portion of the robot arm (18).

9. The device (10) according to any one of the preceding claims, wherein The first row of magnetic elements, the second row of magnetic elements, and the third row of magnetic elements of the gripper of the robotic arm each include at least one magnetic element.

10. The device (10) according to claim 8, wherein The first row of magnetic elements and the second row of magnetic elements of the gripper of the robotic arm each include a single magnetic element, and the third row includes at least three magnetic elements (25c, 25e, 25f), and one magnetic element (25c) of the third row is aligned with the magnetic elements (25a, 25b) of the first and second rows along the extension axis (Y1) of the second reference system (X1, Y1, Z1).

11. The apparatus (10) according to any one of the preceding claims, comprising a second robotic arm.

12. The device (10) according to any one of the preceding claims, wherein The platform (21) comprises at least one magnetized strip (21b) extending along a longitudinal axis (X) parallel to the axis of rotation (XX') of the drum (16) and arranged on a receiving surface (21a) of the platform (21).

13. Method for automatically laying down elastomeric elements (13) in sequence by means of a device (10) for making a green tire, the device (10) being associated with a first reference system (X, Y, Z) and comprising a drum (16) for making a green tire, a platform (21) arranged upstream of the drum (16), at least one robotic arm (18), and at least a first three-dimensional camera, the drum (16) being rotatable about an axis of rotation (XX'), the platform (21) extending along a transverse axis (Y) of a first orthogonal reference system (X, Y, Z) and comprising a flat receiving surface (21a) for receiving an end (13a) of the elastomeric element (13), the at least first three-dimensional camera generating a point cloud of coordinates measured in the reference system associated with the first camera. , having a line of sight toward the platform (21) and being configured to acquire an image of an end portion (13a) of an elastomeric element (13) on the platform (21), the robotic arm (18) comprising at least one gripper (25), the gripper (25) being associated with a second orthogonal reference system (X1, Y1, Z1) different from the first reference system (X, Y, Z), being configured to grip the end portion (13a) of the elastomeric element (13) from above, and comprising at least three rows of magnetic elements (25a, 25b, 25c, 25e, 25f), the at least three rows of magnetic elements (25a, 25b, 25c, 25e, 25f) being parallel to each other and regularly spaced apart from each other along an axis of extension (Y1) of the second reference system (X1, Y1, Z1), characterized in that The method comprises at least: - a laying step (140) comprising a procedure comprising at least a step (150) of clamping the end portion (13a) of the elastomeric element (13), in which the clamping point (P) of the clamp (25) is determined based on the point cloud generated by the first camera p ),as well as - a step (160) of anchoring the end portion (13a) on the outer surface (16a) of the drum, wherein the anchoring points (P1, P2, P3) of each row of magnetic elements (25a, 25b, 25c) on the outer surface (16a) of the drum (16) are determined.

14. The method (100) according to claim 13, wherein: The end portion (13a) extends along an extension axis (Y1) of the second reference system (X1, Y1, Z1), the extension axis (Y1) being angularly offset from the transverse axis (Y) of the first reference system (X, Y, Z); The step (150) of clamping the end portion (13a) of the elastomeric element (13) comprises: a step (151) of collecting an image of the end portion (13a) of the elastomeric element (13) on the platform (21) by a first camera; a step (152) of dividing the image of the end portion (13a) of the elastomeric element (13) on the platform (21) into three regions (Z1, Z2, Z3); and a step (152) of determining an initial clamping point (P) of the clamp (25) in a point cloud of the image collected in the collecting step (151). pi ) of the second reference system (X1, Y1, Z1) and along a second longitudinal axis (X1) perpendicular to the extension axis (Y1) of the second reference system, thereby moving the initial gripping point (P pi ) translates a distance (Ra) corresponding to the radius of each magnetic element (25a, 25b, 25c) of the clamper (25) to correct the initial clamping point (P pi ) to obtain the clamping point (P pf ) step (154), and the clamping point (P pf ) is transferred to the robot arm (18) to clamp the end portion (13a) of the elastomeric element (13) by the clamper (25) (155).

15. The method (100) according to claim 14, wherein: The anchoring step (160) comprises a step (161) of projecting a laser (L1, L2, L3, L4) and a step (162) of acquiring an image of the laying area on the outer surface (16a) of the drum (16) by a second three-dimensional camera, the second three-dimensional camera generating a coordinate point cloud measured in a reference system associated with the second camera and having a line of sight towards the drum (16), the steps (161, 162) of projecting a laser and acquiring an image being performed while the elastomeric element (16) is clamped by the clamp (25). 3), the lasers (L1, L2, L3, L4) comprising a first fixed vertical laser (L1) indicating the center of the drum (16), a second fixed horizontal laser (L2) indicating the azimuth of the laying of the elastomeric element, and two variable vertical side lasers (L3, L4) indicating the longitude of the laying.

16. The method (100) according to claim 15, wherein: The anchoring step (160) further comprises: - a step (163) of processing the image of the paved area, wherein the lasers (L1, L2, L3, L4) and the point cloud generated by the second camera are detected, pixels associated with the lasers (L1, L2, L3, L4) are separated in the image acquired in the acquisition step (162), and intersection pixels (p) at the intersection between the second horizontal laser (L2) and one of the side lasers (L3, L4) are detected I ), - According to the distance (d) between the two rows of magnetic elements (25a, 25b, 25c) r ) and the radius (R a ) to determine the normal of each row of magnetic elements (25a, 25b, 25c, 25e, 25f) below In the plane (Pi(π)) relative to the intersection point (P i ) of the anchor points (P1, P2, P3): the plane of the normal to which the circle (C) fitted on the point cloud of one of the side lasers (L3, L4) lies, and - a step (165) of transmitting the anchor points (P1, P2, P3) of each row of magnetic elements (25a, 25b, 25c, 25e, 25f) to a control module (65) for controlling the gripper (25), the control module (65) being configured to control the rows of magnetic elements (25a, 25b, 25c, 25e, 25f) of the gripper (25), respectively.

17. The method (100) according to any one of claims 13 to 16, comprising an elastomeric element supplying step (110) before the laying step (140), in which the end portion (13a) of the elastomeric element (13) is laid on the surface (21a) of the platform (21) of the device (10).

18. The method (100) according to any one of claims 13 to 17, wherein: The procedure of the laying step (140) further includes: a step (170) of supporting the elastomeric element (13) around the drum, a step (180) of cutting the elastomeric element (13) into a desired length, and a step (190) of welding the cut portion of the elastomeric element (13) to the end portion (13a) anchored on the outer surface (16a) of the drum (16).

Images