Versatile and automated device for removing surface defects by abrasion

Abstract

The invention relates to a device (7) comprising at least one tool (9, 11, 13) having an abrasive element and a surface analysis system (15) housed in a recess, said recess having an opening equipped with at least one flap (17) movable between a masking position and a disengagement position of said surface analysis system (15). The invention also relates to a method implementing such a device. Figure to be published with the abstract: Fig. 3

Description

Title of the invention: Versatile and automated device for removing surface defects by abrasion

[0001] The invention lies in the field of motor vehicle assembly lines and relates in particular to robotic tools and methods for removing uninteresting layers in different types of materials using various operations such as roughing, sanding, grinding, polishing, etc.

[0002] Motor vehicles comprise a body composed of various assembled stamped panels, and on which the vehicle components are mounted. The assembly of the body is generally carried out by robots along an assembly line and comprises, in a first step, the assembly of the body which involves welding operations, such as spot welding operations. In a second step, the openings are mounted on the body. Before mounting the openings and in order to ensure an impeccable visual appearance and technical performance, it is known to carry out various so-called surfacing and / or grinding operations during which certain surfaces are subjected to operations of elimination of uninteresting layers implementing roughing, sanding, grinding, polishing operations, etc. These various operations can be carried out by operators and / or by robots.

[0003] Document US2021 / 0101289 proposes a robot-assisted grinding apparatus which comprises a manipulator; a grinder; a linear actuator coupling the grinder to a tool center point of the manipulator, an extraction system connected to an outlet in a housing of the grinder and a pipe connecting the extraction system to the outlet in the housing of the grinder. The pipe is arranged around the housing of the grinder and the linear actuator in a roughly spiral-shaped manner and is attached at one end to the manipulator.

[0004] The proposed solution is interesting but remains insufficient since it is limited to a single operation, in this case grinding. Indeed, to the applicant's knowledge, no robotic tool known to date can satisfactorily carry out all of said surfacing and / or grinding operations. A solution therefore remains to be found to overcome this problem. Indeed, the time lost for the necessary tool changes depending on the situations encountered and the desired degree of finish increases the total production costs of the vehicles.

[0005] Document CN109514571 proposes a method of using robotic vision and a force sensor for the precise positioning of a car grinding point vehicle grinding. A six-axis robot is included and provided with a 3D vision camera, a grinding disc and a force sensor. The method comprises the following steps: first, the 3D vision camera is used to synthesize the three-dimensional position of a vehicle body; second, the deflection value of the vehicle body is calculated; third, according to the deflection value and the calibration position of the vehicle body, the six-axis robot is instructed to move to the precise position of the vehicle body; fourth, the pressure threshold value of the force sensor is set; fifth, the grinding disc is made to touch the area close to the grinding point on the vehicle body through the six-axis robot; sixth, through the detection of the force sensor, the six-axis robot automatically stops the downward pressure;seventh, the actual descending depth of the grinding disc after the six-axis robot starts to act is calculated; eighth, the compensation value is the difference between the actual depth and the calibrated depth; and ninth, precise control of the grinding point and the grinding depth is achieved. By means of the method described above, the grinding accuracy is improved. ;

[0006] The solution proposed here is also interesting but still remains insufficient since it is also limited to a single operation, which is grinding. Furthermore, the use of a 3D camera increases the maintenance costs related to cleaning the lens due to working in a dusty environment and / or with projections.

[0007] The invention aims to improve the previous situation by providing a solution to at least one of the problems and / or drawbacks encountered in the prior art. In particular, the invention aims to provide a simple and economical method and tool which make it possible to carry out different surfacing and / or grinding operations in a suitable and automated manner.

[0008] To this end and according to a first aspect, the invention relates to a device comprising at least one tool provided with an abrasive element and a surface analysis system, remarkable in that the surface analysis system is placed in a housing, said housing showing an opening equipped with at least one movable flap movable between a masking position and a position for releasing said surface analysis system.

[0009] As will be understood from reading the definition which has just been given, the invention is remarkable in that it combines one or more tools intended to carry out operations of removing layers of materials by means of one or more abrasive elements and a surface analysis system capable of carrying out detection of surface defects. The surface analysis system is configured to identify both the area of ​​action and the most suitable tool(s) for correcting the defect detected. The invention is further remarkable in that the surface analysis system is protected from a dusty environment and / or projections in that it is placed in a housing whose opening is closed by at least one movable flap when the surface analysis system is not in use; preferably, when the tool(s) is in use. Thus, the system is versatile in that it has several functionalities in a single device, while reducing, or even eliminating, the costs associated with cleaning the surface analysis system.

[0010] According to a preferred embodiment, the device is remarkable in that it comprises at least two tools provided with an abrasive element; that is, two different tools. For example, the device may comprise two or three. Incorporating several different tools provided with an abrasive element and therefore adapted to different finishes is advantageous in that it is no longer necessary to make stops for their change. In other words, the cycle time is reduced due to the reduction in times associated with tool changes. Efficiency is increased and production costs are reduced.

[0011] Preferably, at least one tool provided with an abrasive element is selected from a roughing tool, a sanding tool, a grinding tool or a polishing tool. For example, the device comprises two or three tools and all the tools are selected from a roughing tool, a sanding tool, a grinding tool or a polishing tool.

[0012] Ideally, the surface analysis system comprises at least one 3D camera, one 2D camera and / or one laser scanning device.

[0013] According to one embodiment, a suction means is associated with at least one tool provided with an abrasive element. Preferably, a suction means is associated with each of the tools provided with an abrasive element. This configuration therefore provides a flexible system which integrates a defect detection and analysis system and the multiple anchoring of different tools and suction means in the same core. Thus, the operations of detecting and identifying surface defects and the removal of material by abrasion then suction are carried out with a single device.

[0014] Advantageously, at least one tool provided with an abrasive element is associated with a shape compensation system. Preferably, at least one shape compensation system comprises a flexible longitudinal axis support mechanism and / or a tilting mechanism. This configuration allows the device to adapt to complex and / or curved surfaces. This configuration also allows the device to adapt to the thickness of the detected surface defects.

[0015] Preferably, at least one tool provided with an abrasive element is mounted on one of the walls of a housing forming the housing so as to be placed outside said housing. The installation of the tool(s) on the housing forming the housing of the The surface analysis system gives the device a compact and versatile character. Everything is thus carried by the same core, by the same robot hand.

[0016] For example, the movable shutter(s) are moved by translation

[0017] Advantageously, the device further comprises at least one jack arranged for moving the movable shutter(s) between their masking position and their release position. For example, the housing in which the surface analysis system is received is hermetically sealed by the movable shutter(s). The invention has a movable protection mechanism against suspended particles and projections generated during the removal of unwanted materials, thus reducing the maintenance and cleaning time of the optics.

[0018] According to a second aspect, the invention relates to a robot which is remarkable in that it comprises at least one hand which holds a device according to the first aspect; preferably the hand is configured to be able to rotate on itself and to be able to tilt; and / or the hand is carried by an articulated arm.

[0019] According to a third aspect, the invention relates to a surfacing and / or grinding method which is remarkable in that it comprises the following steps:

[0020] positioning a device according to the first aspect opposite a surface to be treated;

[0021] moving the movable shutter(s) from their masking position to their position of release from the surface analysis system;

[0022] activation of the surface analysis system and analysis of the surface to be treated with optionally the movement of the device according to the length and / or the width of said surface;

[0023] identification of the tool(s) to be used depending on the surface defect(s) to be eliminated;

[0024] deactivation of the surface analysis system and closing of the movable shutter(s);

[0025] positioning the selected tool or the first selected tool opposite the area to be treated, activation of said tool, treatment of the surface with optional movement of the device according to the length and / or width of said surface; and deactivation of said tool;

[0026] optionally, positioning the next selected tool opposite the area to be treated, activating said surface treatment tool with optionally moving the device along the length and / or width of said surface; and deactivating said tool.

[0027] Preferably, the device is held by the hand of a robot according to the second aspect.

[0028] Preferably, at least one suction means is associated with at least one tool provided with of an abrasive element and the method implements steps of activating and deactivating the or one of the suction means simultaneously with the tool to which it is partner.

[0029] The invention will be well understood and other aspects and advantages will appear clearly on reading the following description, given by way of example with reference to the attached drawing plates in which:

[0030] [Fig-1] [Fig. 1] is a perspective view of a robot whose hand holds a device according to the invention.

[0031] [Fig.2] [Fig.2] is a perspective view of a device according to the invention, the movable shutter is in the masking position of the surface analysis system.

[0032] [Fig.3] [Fig.3] is a perspective view of a device according to the invention, the movable shutter is in the release position of the surface analysis system.

[0033] [Fig.4] [Fig.4] illustrates the step of positioning the device opposite a surface to be analyzed.

[0034] [Fig.5] [Fig.5] illustrates the step of analyzing the surface to be treated with the displacement of the device according to the length of said surface.

[0035] [Fig.6] [Fig.6] illustrates the step of surface treatment with a first tool.

[0036] [Fig.7] [Fig.7] illustrates the step of surface treatment with a second tool operated after the first tool.

[0037] In the remainder of the description, the term “comprise” is synonymous with “include” and is not limiting in that it allows the presence of other elements in the device or robot or other steps in the method to which it refers. It is understood that the term “comprise” includes the terms “consist of”.

[0038] Similarly, the terms "lower", "upper", "high" and "low" will be understood according to their usual definition, in which the terms "lower" and "low" indicate a greater proximity to the ground in the vertical direction than the terms "upper" and "high" respectively.

[0039] Reference is first made to [Fig.l] illustrating a robot 1 according to the invention. The robot 1 comprises an articulated arm 3 so that it can be moved in all directions. The robot 1 has a hand 5 at the end of its arm 3 configured to be able to rotate on itself and to be able to tilt. The hand 5 of the robot holds a device 7 according to the invention.

[0040] With reference to Figures 2 and 3, the device 7 comprises at least one tool (9, 11, 13) provided with an abrasive element and a surface analysis system 15. According to the invention, the surface analysis system 15 is placed in a housing showing an opening equipped with at least one movable flap 17 movable between a masking position (see [Fig.2]) and a release position (see [Fig.3]) of said surface analysis system 15.

[0041] The device 7 may comprise one or more tools (9, 11, 13) provided with an abrasive element. For example, it may comprise at least two tools (9, 11, 13) provided with a abrasive element. In the embodiment illustrated in Figures 1 to 7, the device comprises three tools (9, 11, 13) provided with an abrasive element. However, a person skilled in the art will be able to provide the device with four or more tools provided with an abrasive element. Similarly, the device can also carry other types of tools not provided with an abrasive element, for example a paint sprayer, instead of a tool provided with an abrasive element. For example, the device can comprise 3 tools, two of which are provided with an abrasive element but not the third.

[0042] According to one embodiment, at least one tool (9, 11, 13) provided with an abrasive element is chosen from a roughing tool, a sanding tool, a grinding tool (11, 13) or a polishing tool (9). For example, the device may comprise two grinding tools with different grains allowing different types of finishes to be carried out. The different tools mounted on the device are known to those skilled in the art and are commercially available. Roughing, grinding, sanding or polishing tools are available from FERROBOTICS COMPLIANT ROBOT TECHNOLOGY GMBH under the trade name Active Orbital Kit.

[0043] According to a preferred embodiment, the or at least one of the tools (9, 11, 13) provided with an abrasive element is associated with a shape compensation system 19, preferably comprising a flexible support mechanism and / or a tilting mechanism. The presence of a shape compensation system allows the tool to adapt intelligently and easily to complex surfaces, thus automatically measuring the applied force, being able to compensate for sudden counter-forces.

[0044] The abrasive element is carried by a treatment head of the tool which is itself carried by the flexible support mechanism of longitudinal axis and / or the tilting mechanism. A flexible support system of the “compliance” type is known to those skilled in the art and ensures control of the contact force of the head with the part to be treated. An example of compliance is disclosed in application US 2014 / 000583. The compliance (or flexible support mechanism) allows a relative movement of the head relative to the surface to be treated along the longitudinal axis of the compliance. The tilting mechanism allows the treatment head to be tilted.

[0045] Such shape compensation systems are known to those skilled in the art and are, for example, marketed by the company FERROBOTICS COMPLIANT ROBOT TECHNOLOGY GMBH under the trade name Active Compliant Technology (ACT) and described in document WO2020243762. They are also known from document FR3033511 from the company GEBE2 PRODUCTIQUE.

[0046] According to a preferred embodiment of the invention, a suction means 21 is associated with at least one tool (9, 11, 13) provided with an abrasive element. Preferably, a suction means 21 is associated with each of the tools (9, 11, 13) provided with an abrasive element. The presence of this or these suction means makes it possible to eliminate all or part of the dust and / or projections generated by the surface treatment operations using the abrasive elements. Advantageously, the suction elements 21 are fixed to the housing forming the housing receiving the surface analysis system 15 by at least one flange 23.

[0047] Although they are of undeniable effectiveness, it has been found that the presence of suction means 21 is not entirely sufficient for optimal protection of the surface analysis system 15. This is why the invention places the surface analysis system 15 in a protective casing forming a housing.

[0048] According to a preferred embodiment, the different tool(s) (9, 11, 13) are advantageously mounted on the walls of a casing forming a housing in which a surface analysis system 15 is arranged. Thus the tool(s) are placed outside said housing. The housing can be closed or opened by means of at least one movable flap 17. When the movable flap is in the masking position ([Fig.3]), the person skilled in the art will benefit from the housing being hermetically closed so as not to allow dust and other projections to enter the housing and come into contact with the surface analysis system 15. The movable flap(s) 17 can be moved by any means. In the illustrated embodiment, the housing can be closed by a single movable flap 17 which is moved between its release and masking positions by translation by one or more jacks 25.

[0049] The surface analysis system 15 can be of any kind and preferably comprises at least one 3D camera, one 2D camera and / or one laser scanning device. Such surface analysis systems are known to those skilled in the art and will not be described further. It is simply indicated that the system will identify the surface defects in which material is to be removed and evaluate the thickness of the defect and, thereby, the quantity of material to be removed. Based on the information obtained using the camera or laser scanning, the device will choose the most suitable tool or sequence of tools and remove the unwanted excess material by the tool(s).

[0050] According to one embodiment of the invention, the method implemented comprises the following steps illustrated in Figures 4 to 7:

[0051] positioning a device 7 according to the invention opposite a surface 27 to be treated (here a side of a body). This step is illustrated in [Fig.4].

[0052] movement of the movable flap(s) 17 from their masking position to their position of release from the surface analysis system 15.

[0053] activation of the surface analysis system 15 and analysis of the surface to be treated with movement of the device 7 according to the length and / or the width of said surface 27. This step is illustrated in [Fig.5]. The width can be understood as being the height. In the case of a complex surface, the movement of the device 7 can be done in the three directions, namely the length, the width and the height of said surface.

[0054] identification of the tool(s) (9, 11, 13) to be used depending on the surface defect(s) to be eliminated.

[0055] deactivation of the surface analysis system 15 and closing of the movable shutter(s) 17. It will be noted that the surface analysis system 15 is only revealed when it is in use. Outside of these times, it remains preferentially protected in the housing closed by the movable shutter(s) 17, whether the tool(s) are activated or not.

[0056] positioning the first tool 13 selected opposite the area to be treated, activation of said tool 13, treatment of the surface 27 with movement of the device 7 according to the length and / or the width of said surface 27; and deactivation of said tool 13. The width can be understood as being the height. In the case of a complex surface, the movement of the device 7 can be done in the three directions, namely the length, the width and the height of said surface. When only one tool is selected, the implementation of the method ends with the deactivation of the tool, the first tool is the only tool selected. In the illustrated case, a sequence using two tools has been chosen by the surface analysis system 15. This sequence begins with the activation and use of a first tool, here a grinding tool 13 as illustrated in [Fig.6] and continues with the activation and use of a second tool, here a polishing tool 9 as illustrated in [Fig.7].

[0057] positioning a second tool 9 selected opposite the area to be treated, activation of said second tool 9, treatment of the surface with movement of the device 7 according to the length and / or width of said surface; and deactivation of said second tool 9.

[0058] The latter can optionally be repeated with a third tool if the sequence so provides. Thus, more generally, the method comprises an optional step of positioning the next selected tool (9, 11, 13) opposite the area to be treated, activating said tool (9, 11, 13), treating the surface with optionally moving the device (7) along the length and / or width of said surface; and deactivating said tool (9, 11, 13).

[0059] In the implementation illustrated in Figures 4 to 7, it will be noted that the grinding tool 13 (here the first tool in the sequence) is associated with a suction means 21. The method is advantageous in that it implements steps of activating and deactivating the or one of the suction means 21 simultaneously with the tool (9, 11, 13) with which it is associated.

Claims

Claims

1. Device (7) comprising at least one tool (9, 11, 13) provided with an abrasive element and a surface analysis system (15) placed in a housing, said housing showing an opening equipped with at least one movable flap (17) movable between a masking position and a release position of said surface analysis system (15), characterized in that it comprises at least two tools (9, 11, 13) provided with an abrasive element, at least one tool (9, 11, 13) provided with an abrasive element is chosen from a roughing tool, a sanding tool, a grinding tool (11, 13) or a polishing tool (9).

2. Device (7) according to claim 1, characterized in that the surface analysis system (15) comprises at least one 3D camera, one 2D camera and / or one laser scanning device.

3. Device (7) according to one of the preceding claims, characterized in that a suction means (21) is associated with at least one tool (9, 11, 13) provided with an abrasive element; preferably, a suction means (21) is associated with each of the tools (9, 11, 13) provided with an abrasive element.

4. Device (7) according to one of the preceding claims, characterized in that at least one tool (9, 11, 13) provided with an abrasive element is associated with a shape compensation system (19); preferably, at least one shape compensation system (19) comprises a flexible longitudinal axis support mechanism and / or a tilting mechanism.

5. Device (7) according to one of the preceding claims, characterized in that at least one tool (9, 11, 13) provided with an abrasive element is mounted on one of the walls of a housing forming the housing so as to be placed outside said housing.

6. Device (7) according to one of the preceding claims, characterized in that the movable flap(s) (17) are moved by translation and / or in that the device further comprises at least one jack (25) arranged for moving the movable flap(s) (17) between their masking position and their release position.

7. Robot (1) characterized in that it comprises at least one hand (5) which holds a device (7) according to one of the preceding claims; preferably, the hand (5) is configured to be able to rotate on itself and to be able to tilt; and / or the hand (5) is carried by an articulated arm (3).

8. Surfacing and / or grinding method characterized in that it comprises the following steps: positioning a device (7) according to one of the preceding claims opposite a surface to be treated; moving the movable flap(s) (17) from their masking position to their position for releasing the surface analysis system (15); activating the surface analysis system (15) and analyzing the surface to be treated with optionally moving the device (7) along the length and / or width of said surface; identifying the tool(s) (9, 11, 13) to be used depending on the surface defect(s) to be eliminated; deactivating the surface analysis system (15) and closing the movable flap(s) (17);positioning the selected tool (9, 11, 13) or the first selected tool (9, 11, 13) opposite the area to be treated, activating said tool (9, 11, 13), treating the surface with optionally moving the device (7) along the length and / or width of said surface; and deactivating said tool (9, 11, 13); optionally, positioning the next selected tool (9, 11, 13) opposite the area to be treated, activating said tool (9, 11, 13), treating the surface with optionally moving the device (7) along the length and / or width of said surface; and deactivating said tool (9, 11, 13).;

9. Surfacing and / or grinding method according to claim 9, characterized in that at least one suction means is associated with at least one tool (9, 11, 13) provided with an abrasive element and in that the method implements steps of activating and deactivating the or one of the suction means simultaneously with the tool (9, 11, 13) with which it is associated.

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