METHOD AND UNIVERSALLY USABLE DEVICE FOR PRODUCING A PREDETERMINED BREAKING LINE, AND PROCESSING SYSTEM COMPRISING SUCH A DEVICE

Abstract

A method and device for producing a predetermined breaking line in a vehicle interior trim part with a scanning laser beam. An actual position of the vehicle interior trim part held in a working plane relative to a laser scanning device is detected by a camera and the actual position of the predetermined breaking line is derived. A stored desired position for a scan figure corresponding to the predetermined breaking line is corrected to an actual position, whereby the predetermined breaking line is produced at a predetermined position on the vehicle interior trim part during scanning of the scan figure. A positional shift of the scan figure becomes possible because a sensor matrix with an upstream diffuser is used, which can detect transmitted components of the laser beam independently of the position of the laser beam along the scan figure.

Claims

1. A method for producing a predetermined breaking line in a vehicle interior trim part, comprising: picking up and arranging a vehicle interior trim part in a working plane between a sensor matrix and a processing head containing a laser scanning device, scanning a laser beam, using the laser scanning device, on an inner side of the vehicle interior trim part, describing a scan figure, along the predetermined breaking line, wherein material removal in the form of holes is effected in each case down to a predetermined residual wall thickness at a plurality of processing locations along the predetermined breaking line and measured values are acquired by individual sensors of the sensor matrix during the material removal caused by a portion of the laser beam transmitted at the processing locations, forming a respective comparative measured value from measured values acquired simultaneously and comparing with a reference measured value to which the predetermined residual wall thickness is assigned, and controlling a laser generator to emit the laser beam as a function of a comparison result, acquiring measured values of all individual sensors that lie above a predefined threshold value so that the predetermined breaking line can be positioned as desired within a field of view of the sensor matrix, optically detecting an actual position of the vehicle interior trim part relative to the laser scanning device and deriving from the actual position of the vehicle interior trim part an actual position of the predetermined breaking line relative to the laser scanning device, and correcting a desired position of a scan figure stored for a desired position of the predetermined breaking line for scanning the predetermined breaking line to an actual position of the scan figure, and producing the predetermined breaking line at a predetermined position on the vehicle interior trim part during scanning of the scan figure.

2. The method for producing a predetermined breaking line in a vehicle interior trim part according to claim 1, wherein: the method is carried out on three vehicle interior trim parts with a time overlap, and the method further comprises arranging the vehicle interior trim parts one after the other in the working plane by two feeders and determining an actual position of the scan figure individually for a respective actual position of the respective vehicle interior trim part.

3. The method for producing a predetermined breaking line in a vehicle interior trim part according to claim 2, wherein: a first of the three vehicle interior trim parts is processed while held in a first of the two feeders, while the second feeder transports the finished second vehicle interior trim part to an output location, and then the third vehicle interior trim part, which has not yet been processed, is picked up at an input location and transported for processing.

4. The method for producing a predetermined breaking line in a vehicle interior trim part according to claim 1, wherein the transmitted part of the laser beam is scattered so that measured values can be acquired by more individual sensors.

5. A device for producing a predetermined breaking line in a vehicle interior trim part, comprising: a sensor matrix, a diffuser, a camera, a laser generator, a processing head arranged in a defined manner with respect to the sensor matrix and an intermediate working plane, said processing head containing a laser scanning device, which is connected to the laser generator, in which the vehicle interior trim part to be processed is arranged, and a control and computing unit, wherein: a field of view of the sensor matrix is larger than a maximum extension of the predetermined breaking line, the camera is directed towards the working plane, and is configured to detect an actual position of the vehicle interior trim part arranged in the working plane in relation to the laser scanning device, from which an actual position of the predetermined breaking line is derived therefrom, and the control and computing unit is configured to bring the scan figure into alignment with the predetermined breaking line, and the diffuser is arranged upstream of the sensor matrix.

6. The device for producing a predetermined breaking line in a vehicle interior trim part according to claim 5, wherein individual sensors of the sensor matrix each have a sensitivity that is matched to each other so that the sensor matrix has a homogeneous sensitivity.

7. A processing system comprising a device for producing a predetermined breaking line in a vehicle interior trim part according to claim 5, the processing system including at least two feeders by which a vehicle interior trim part is alternately transported and positioned in the working plane of the device for producing the predetermined breaking line.

8. The processing system according to claim 7, wherein the at least two feeders include multi-axis robots which hold the vehicle interior trim parts suspended in the working plane in each case.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The invention will be explained in more detail below with reference to exemplary embodiments and drawings. In the drawings:

[0040] FIG. 1 is a schematic representation of a device for producing a predetermined breaking line in a vehicle interior trim part, and

[0041] FIG. 2 shows a processing system comprising a device according to FIG. 1 and two feeding means.

DETAILED DESCRIPTION

[0042] FIG. 1 shows a schematic representation of a device according to the invention for producing a predetermined breaking line 0 in a vehicle interior trim part 1. Said device contains a sensor matrix 3, a processing head 4 arranged in a defined manner with respect to it and an intermediate working plane A in which the vehicle interior trim part 1 to be processed is arranged, as well as a control and computing unit 5, which may include a controller and a computer or a combination thereof. The working plane A is adapted to the surface contour of the vehicle interior trim part 1 and need not be a geometric plane. The processing head 5 contains a laser generator 7, or is connected to a laser generator 7, as well as a laser scanning device 6 and a camera 8 fixed with respect to the laser scanning device 6. The laser generator 7, the laser scanning device 6 and the camera 8 are connected to the control and computing unit 5 via signals.

[0043] A field of view of the camera located in the working plane A advantageously covers at least one field of view of the sensor matrix located in the working plane A. Advantageously, both fields of view in the working plane A are of equal size and completely cover each other. A scanning range of the laser scanning device, determined by the maximum deflection of a laser beam S emitted by the laser generator 7, in the x and y directions of a scanner coordinate system, is matched to the size of the field of view of the sensor matrix so that said field of view can be scanned as completely as possible. The camera 8 and the laser device 6 are fixedly connected to each other, whereby a camera coordinate system of the camera has a fixed, known relative position to the scanner coordinate system of the laser scanning device and whereby the image coordinates of each image point of an image generated by the camera 8 can be assigned to the scan coordinates of a scanner position of the laser scanning device 6, respectively.

[0044] For the complete creation of a predetermined breaking line 2 with a device according to the invention, the field of view of the sensor matrix must be larger than the maximum extension of a possible predetermined breaking line 2.

[0045] A significant advantage of a device according to the invention is that a vehicle interior trim part 1 to be processed, which is held in the working plane A, only needs to be roughly positioned. Rough positioning means here that the predetermined breaking line 2 to be produced need only lie within the field of view of the camera and within the scan field of the laser scanning device. This makes it possible to hold the vehicle interior trim part 1 in the working plane A, e.g. using a multi-axis robot 9, see FIG. 2, instead of placing it in a part-specific holding device, with which a higher positioning accuracy is achieved. It is also possible to pick up the vehicle interior trim part 1 less precisely, for example with suction cups 10, which is particularly advantageous for holding larger vehicle interior trim parts 1, compared to a gripper 11. The camera 8 has the function of optically recording the vehicle interior trim part 1, which is only roughly positioned in the working plane A, in order for the computing and control unit 5 to determine an actual position for the vehicle interior trim part 1 and derive an actual position for the predetermined breaking line from the image data obtained. The desired position of a scan figure (predefined processing coordinates) stored for a desired position of the predetermined breaking line is corrected to an actual position (corrected processing coordinates) and the laser scanning device 6 is controlled in the actual position of the vehicle interior trim part 1 to execute the scan figure along the predetermined position of the predetermined breaking line. For this purpose, the relative position of the vehicle interior trim part 1 in the camera coordinate system and thus relative to the scanner coordinate system is determined from the image data. To this end, defined features on the vehicle interior trim part 1, to which the predetermined breaking line 2 has a known fixed positional relationship, are determined in the image data.

[0046] Advantageously, the computer and control unit 5 can store not only one scan figure but several scan figures, each related to a desired position or also related to different desired positions of a predetermined breaking line to be produced.

[0047] The device can therefore be used for various vehicle interior trim parts that differ in the position and contour of the predetermined breaking line.

[0048] Using the device to form the predetermined breaking line 2 in the vehicle interior trim part 1 exactly at the predetermined position, even though the vehicle interior trim part 1 was only roughly positioned when it was arranged in the working plane A, is made possible by the use of the sensor matrix 3 in conjunction with image data-based control of the laser scanning device 6. The sensor matrix 3 has a homogeneous sensitivity, which was preferably adjusted by electronically tuning the sensitivity of the individual sensors of the sensor matrix 3 to each other. As a result, an identical comparative value is formed for an identical residual wall thickness, regardless of the number and position of the individual sensors that supply a measured value.

[0049] A diffuser 12 is arranged upstream of the sensor matrix 3. The portion of the laser beam transmitted at the individual processing locations during the production of the predetermined breaking line 2 (also to be understood here as secondary radiation caused by the laser beam at the processing location) is scattered by the diffuser 12 and is therefore distributed over a larger number of individual sensors than if no diffuser were arranged upstream.

[0050] A device 0 according to the invention is particularly suitable for installation in a production line, since it is compatible with a wide variety of feeding means or feeders 13 due to its low requirements for the positioning accuracy of the vehicle interior trim part to be processed with respect the device.

[0051] Together with at least one feeding means 13, preferably two, it forms a processing system, see FIG. 2, in which a vehicle interior trim part 1 is alternately removed from a stack by the feeding means 13 and transported into the working plane A of the device for producing a predetermined breaking line 2.

[0052] Particularly high flexibility in movement is provided if the feeding means 13 include a multi-axis robot 9, which holds the vehicle interior trim parts 1 suspended in the working plane A in each case.

[0053] In a method according to the invention for producing a predetermined breaking line in a vehicle interior trim part 1, the vehicle interior trim part 1 is picked up and arranged in a working plane A between a sensor matrix 3 and a processing head 4 arranged in a defined manner with respect thereto and containing a laser scanning device 6.

[0054] The laser scanning device 6 directs a laser beam S to an inner side of the vehicle interior trim part and scans said laser beam S, describing a scan figure, along the predetermined breaking line 2. This causes material to be removed in the form of holes, down to a predetermined residual wall thickness in each case, at a plurality of processing locations along the predetermined breaking line 2. With increasing material removal, the residual wall thickness at each processing location decreases until individual sensors of the sensor matrix detect transmitted components of the laser beam during material removal and record measured values.

[0055] A comparative measured value is formed from the measured values acquired simultaneously by each individual sensor of the sensor matrix and compared with a reference measured value to which the predetermined residual wall thickness is assigned.

[0056] This means that, regardless of the location, each of the individual sensors which provide a acquired measured value form an identical comparison value when the same residual wall thickness is reached at the respective processing location.

[0057] A laser generator 7 emitting the laser beam S is controlled as a function of a comparison result between the comparison value and the reference value. Controlling here can mean that the laser generator is switched off or that the laser parameters, e.g. a pulse length or a pulse amplitude, are changed.

[0058] The measured values of all individual sensors that lie above a predefined threshold value are acquired, which means that the predetermined breaking line can be positioned as desired within a field of view of the sensor matrix. However, knowledge of the rough positioning of the vehicle interior trim part also allows conclusions to be drawn about the area of the sensor matrix in which individual sensors will supply a measurement signal, which means that not all individual sensors have to be read out.

[0059] Whereas in the case of exact positioning of the vehicle interior trim part relative to a laser scanning device, as is usual in the prior art, the predetermined breaking line is arranged in a desired position, so that a scan figure stored for this purpose describes the predetermined breaking line, in the present case, according to the invention, the desired position of the scan figure stored for the desired position of the predetermined breaking line is corrected to an actual position for the scan figure assigned to the concrete actual position.

[0060] For this purpose, the actual position of the vehicle interior trim part relative to the laser scanning device is optically acquired by a camera and the actual position of the predetermined breaking line relative to the laser scanning device is derived therefrom.

[0061] A desired position of the scan figure stored for the desired position of the predetermined breaking line is corrected to an actual position of the scan figure, thereby aligning the scan figure with the predetermined breaking line.

[0062] The process is advantageously carried out on three vehicle interior trim parts with a time overlap, arranging the vehicle interior trim parts one after the other in the working plane by means of two of the feeding means.

[0063] In this case, the first of the three vehicle interior trim parts is preferably processed while held in the first of the two feeding means, while the second feeding means transports the finished second vehicle interior trim part to an output location, and then the third vehicle interior trim part, which has not yet been processed, is picked up at an input location and transported for processing.

[0064] Ideally, the sensor matrix is homogeneous in sensitivity over its extent. This can be optimized by scattering the transmitted part of the laser beam, which means that more individual sensors detect transmitted parts and record measured values, thus relativizing any fluctuation.

LIST OF REFERENCE NUMERALS

[0065] 0 device (for producing a predetermined breaking line) [0066] 1 vehicle interior trim part [0067] 2 predetermined breaking line [0068] 3 sensor matrix [0069] 4 machining head [0070] 5 control and computing unit [0071] 6 laser scanning device [0072] 7 laser generator [0073] 8 camera [0074] 9 multi-axis robot [0075] 10 suction cup [0076] 11 gripper [0077] 12 diffuser [0078] 13 feeders or feeding means [0079] A working plane [0080] S laser beam