CN110652034A

CN110652034A - Device and method for optically measuring on a rod of articles of the tobacco processing industry and use of an optical measuring device

Info

Publication number: CN110652034A
Application number: CN201910574589.9A
Authority: CN
Inventors: P.施特劳贝; R.赫罗克; H-H.贝恩克; S.罗泽; A.埃尔雅拉德
Original assignee: Rainbow Neon Machinery Manufacturing Co Ltd
Current assignee: Kolber Technology Co ltd
Priority date: 2018-06-29
Filing date: 2019-06-28
Publication date: 2020-01-07
Anticipated expiration: 2039-06-28
Also published as: DE102018129256A1; CN110652034B

Abstract

Optical measuring device (10) for the determination of at least one characteristic, quality value and/or service data of an endlessly processed product rod (11) of the tobacco processing industry on the basis of triangulation, comprising: at least one light source (12) for generating a plurality of incident light paths (16) that fall onto the surface of the article band (11) around its perimeter; at least three light sensitive elements (29-31) arranged in the triangulation system with respect to the incident light path (16); a digital evaluation device (73) is provided for determining the 3-dimensional surface profile of the product strip (11) from the measurement signals transmitted by the light-sensitive elements (29-31). The optical measuring device (10) has at least one light deflecting element (14, 17, 24, 25) between the light source (12) and the product web (11) for deflecting at least one incident light path (16) and/or between the product web (11) and at least one light sensitive element (29-31) for deflecting at least one exit light path (38-40).

Description

Device and method for optically measuring on a rod of articles of the tobacco processing industry and use of an optical measuring device

Technical Field

The invention relates to an optical measuring device for the triangulation-based acquisition of at least one characteristic, quality value and/or service data of an endlessly processed product rod of the tobacco processing industry, comprising: at least one light source for generating a plurality of incident light paths, the incident light paths falling onto the surface of the article strip around the perimeter of the article strip; at least three light sensitive elements arranged in a triangulation system with respect to an incident light path; a digital evaluation device, which is provided to determine the 3-dimensional surface profile of the product strip from the measurement signals transmitted by the light-sensitive elements. The invention further relates to the use of such an optical measuring device and to a corresponding optical measuring method.

Background

In order to know, in particular, the diameter of the tobacco rod in a cigarette manufacturing machine, an optical measuring device according to the shadow principle is known from DE 10304503 a 1. The light source and the sensor run around the tobacco rod in such a way that a spiral path of the measurement position along the tobacco rod is obtained on the basis of the advancing of the tobacco rod in the rod or advancing direction. The known optical measuring device has movable components and requires a strip length of up to 12m, based on the measuring principle used for determining the diameter of the profile.

The high demand for new products and product information requires that the line profiles and thus in particular also the diameter values be obtained at a significantly shorter distance. Another object is to avoid moving parts in the measuring device in order to reduce losses and to reduce the space requirements of the measuring device.

After the endless strip has passed through the measuring device, the endless strip is divided into rods of the same length by means of a cutting device. In some applications, each rod may be assembled in segments from different materials. The passing segment is typically closed with wrapping paper. However, the profile is represented by built-in segments. For each segment block, quality parameters, in particular diameter, ovality, etc., are required in order to check and optimize the quality of the overall production and the production flow. Today no measurement system is available for this measurement task.

DE 102004057092 a1 discloses a device for detecting the diameter and/or cross-sectional shape of rod-shaped articles of the tobacco processing industry, which has a plurality of light sources arranged around the articles for emitting light onto the articles, wherein a position-sensitive sensor is provided in each case relative to each light source for receiving light scattered by the surface of the article and for detecting the height profile of the article.

Disclosure of Invention

The object of the invention is to provide a measuring device in which the losses are reduced and the space requirements are reduced, and which provides the required or desired quality values, characteristics and/or service information for each rod and, in the case of multi-segment rods, for each segment block.

The invention solves this object with the features of the independent claims.

For profiling the product strip around its circumference, the measurement principle of optical triangulation, namely the light section method (Lichtschnittverfahren), is used. The incident light is projected onto the surface of the product web in a circumferential manner around the entire circumference of the product web, i.e. around a full 360 °, and there generates a clear light ray which surrounds the product web. A plurality of light-sensitive elements are arranged in the triangulation system according to the invention relative to the incident light path in order to respectively capture partial profiles of the product strip.

At least three light-sensitive elements are provided in order to be able to detect all points of the strip profile around the entire circumference and to obtain meaningful image information from the light-sensitive elements also for the corresponding edge regions of the product strip. All photosensors advantageously capture a defined angular range of the strip profile simultaneously. A 360 deg. perimeter profile may be established from the light reflected by the article strip and captured by the photosensitive element.

According to the invention, the optical measuring device has at least one light deflection element between the light source and the product web for deflecting at least one incident light path and/or between the product web and at least one light-sensitive element for deflecting at least one outgoing light path. In this way, the light source, the light-sensitive element and/or the further optical element can be positioned at a desired location, which enables a particularly compact or space-saving arrangement.

Advantageously, at least one light deflecting element can be arranged in each outgoing light path, which also increases the freedom in the arrangement of the optical elements.

The term "beam path" is to be understood as broadly as possible and here encompasses not only the incident beam path between the light source and the product strip, the outgoing beam path between the product strip and the light-sensitive element, but also (sub-) beam paths between the light source, the product strip, the light-sensitive element and the beam-deflecting element.

This can be achieved in that the light beam emitted by the light source is appropriately deflected in order to generate a plurality of light beams or light fans (Lichtf ä chern) which are incident on the product strip.

In an advantageous embodiment, the light source generates a main radiation fan, wherein a part of the main radiation fan falls onto the product strip and another part of the main radiation fan passes by the product strip on one or both sides thereof and is directed onto the product strip after passing by the product strip by means of at least one light deflecting element.

Preferably, the optical measuring device has at least three incident light paths arranged around the circumference of the product strip, in order to be able to illuminate the product strip as uniformly and brightly as possible around the total circumference of the product strip. It may be sufficient for this purpose for exactly three light paths to fall onto the product strip.

Alternatively, it is also possible to provide a plurality of light sources for generating the light paths which fall onto the product strip.

Advantageously, a collimating lens is arranged in the incident light path in order to collimate the incident beam and thus to obtain a uniform beam density or illumination of the strip surface in the measurement field. But may also be switched without a collimating lens.

From the three-dimensional surface profile of the product strip measured or calculated by means of the optical measuring device, a plurality of desired quality values, characteristics and/or service data can be determined.

The quality values that can be known are, for example: the diameter and circumference of the article strand; ovality; out-of-roundness factors, such as the standard deviation of the strip profile radii; the position of the seam of the wrapping strip, for example as an angle. The quality values are advantageously calculated and specified for each rod, for each segment and/or as an average value for the production. In general, one or more standard deviations (or differences) of one or more of the above parameters may contain meaningful information and may be known for further processing.

The features of the product strip to be detected are, in particular, features which can be noted as defects in the product, i.e. in the cut strip. The features of this form are for example: profile defects on sub-blocks and/or on individual segments of a strip; wrapping the bonding part of the strip in the direction of the endless strip; a bond site defect at a bond joint on a sub-block of the strip; foreign matter on the bar adheres.

The service data to be advantageously known are, for example: bar vibration (Strangschwingen); uneven longitudinal seams of the wrapping strip, for example as a standard deviation via production; outline region diagram (profilelot); 3D region map.

According to the foregoing, the photosensitive element is advantageously a position-sensitive imaging sensor, in particular a CMOS sensor, in order to enable the application of triangulation in data evaluation.

Preferably, the incident light beam is incident perpendicularly on the product strip, so that a closed ray around the circumference of the product strip is obtained.

Advantageously, the drawing plane of the light-sensitive elements is arranged obliquely with respect to the corresponding optical axis, i.e. the optical axis of the respective lens. This arrangement according to Scheimpflug-Regel enables: a sharp image is optimally produced in the drawing plane of the profile plane to be measured.

The scanning rate of the measuring device is advantageously sufficiently high and is in particular selected such that the axial distance between the two measuring profiles is smaller than or equal to the shortest segment length in the product strip. This can be achieved: at least one measurement profile is obtained for each segment in the article strip.

A controller, in particular an FPGA and/or a microprocessor, can advantageously be associated with each light sensor for preprocessing, pre-evaluating and/or data compression of the signals of the light sensors. In this embodiment, the data of all controllers are advantageously sent to a main control and/or data integration unit, in particular an FPGA and/or a microprocessor, for further processing.

The measuring module according to the invention advantageously comprises the optical measuring device described above and a housing enclosing the measuring device, which has a through-opening for the through-guiding of the product strip through the measuring module. In this case, the previously described controller and the main control and/or data integration unit are advantageously likewise arranged in the measuring module. It is particularly advantageous if the distance of the through-openings from the nearest housing edge is less than or equal to half the distance between two product strips to be processed in a double strip machine. In this case, two identically constructed measuring modules can be used, the second measuring module being arranged rotated by 180 ° relative to the first measuring module.

The invention furthermore proposes the use of an optical measuring device as described above for measuring quality values, characteristics and/or service data of individual segments in endlessly repeating multi-segment rod segments of a product strip.

According to a further aspect of the invention, a method is proposed for optically measuring quality values, characteristics and/or service data of an endlessly processed product strand of the tobacco processing industry by means of the optical measuring device described above, wherein the measurement is advantageously carried out synchronously with the division of the product strand into rods and/or segments and/or synchronously with the production speed.

Drawings

The invention is explained below with the aid of preferred embodiments with reference to the drawings. Here:

fig. 1 shows a perspective view of an optical measuring device;

fig. 2 shows a schematic diagram for illustrating the triangulation or truncation method used;

FIG. 3 shows a perspective view of a light generating system in an optical measuring device;

FIG. 4 shows a perspective detail view of the central region of the optical measuring device from FIG. 1;

FIG. 5 shows a perspective top view of an article bar with an exemplary projected laser line;

FIG. 6 shows a schematic cross-section through a strip of articles with an equidistant arrangement of photosensitive elements;

fig. 7 shows a perspective view of two measuring modules for a double-sliver machine;

figure 8 shows a perspective view of a cigarette maker with a measuring module arranged in a dispensing unit;

FIG. 9 shows a schematic diagram starting from a measuring device for illustrating data processing and evaluation;

FIG. 10 shows a schematic view of an article bar assembled from multi-segment bars;

FIGS. 11 and 12 illustrate exemplary profile region diagrams in a polar or Cartesian coordinate system; and

fig. 13 shows an exemplary 3D profile region map.

Detailed Description

The measuring device 10 is used for measuring a three-dimensional 360 ° surface profile of an endlessly processed product rod 11 of the tobacco processing industry, for example a tobacco rod, a filter rod or a multi-segment filter rod. The product strand 11 is pushed in the longitudinal direction in a rod-forming machine 83 of the tobacco processing industry, as is illustrated in fig. 8.

An example for converting a measuring device 10 under narrow structural space conditions is shown in fig. 1. The measuring device 10 comprises a light generating system 9, which is shown in fig. 3 in a separate state in view of a better overview, that is to say without the cameras 35 to 37 and the beam deflection elements 41 to 49 on the exit side. The light generation system 9 advantageously has exactly one laser source 12 which is provided for generating the laser fan 13 and for this purpose (see fig. 2) may for example have a laser diode 74 or a laser and suitable optical means 75, for example a cylindrical lens, or have movable scanning means. The light fan 13 is deflected by means of a deflection element 14 such that the deflected light fan 15, viewed in the strip direction, is substantially centered (see fig. 2) and falls vertically onto the product strip 11. In the light path 16 incident on the product web 11, which comprises the

light fans

13, 15, 18, a collimator lens 17 is advantageously arranged in order to produce substantially parallel light fans 18 from the dispersed

light fans

13, 15.

The deflection by the deflection element 14 is advantageously carried out about an angle in the angular range of at least 90 °, further advantageously at least 135 °, for example between 135 ° and 180 °.

The widened and optionally collimated incident light path 16 is advantageously projected onto the strip 11 from two additional and thus a total of three sides by means of mirrors 24, 25 in order to obtain a light ray 21 which surrounds the circumference of the strip 11. This is described more precisely below with reference to fig. 3.

The advantageously parallel incident

light paths

16, 18 fall on the product strip 11 in an intermediate region 19, which can be designated as the main radiation fan. Previously, the parallelized light fan 18 also traversed a protective tube 20 transparent to the laser light, which can be made of glass, for example, and arranged in the region of the measuring site around the circumference of the product strand 11, so that the image sensors 29 to 31 of the cameras 35 to 37 (see fig. 1) remain unaffected by dust and foreign particles. An air flow can be generated which flows parallel to the wall of the protective tube 20 in order to keep the measuring area clean.

The central region 19 of the fan 18 incident on the product strip 11 produces a laser line 21 on the surface of the product strip 11, in particular on the wrapping material of the product strip, as can be seen, for example, in fig. 5.

The parallelized fans 18 have a total width B which is at least 3 times, advantageously at least 4 times, still further advantageously at least 5 times the width B of the product strip 11, see fig. 3. Thus, on both sides of the product web 11, the lateral regions 22, 23 of the parallelized fan 18 can pass through the product web 11.

On the rear side of the product strand 11, considered from the

incident radiation fans

15, 18 or the incident beam path 16, a further deflection element 24, 25 is provided on one or preferably both sides of the product strand 11, which deflects in each case one of the lateral regions 22, 23 of the radiation fan 18 in such a way that it falls as an incident beam fan 26, 27 from the rear side onto the surface of the product strand 11. Advantageously, the deflection by each deflection element 24, 25 takes place about an angle in the range from 120 ° to 180 °, for example about 150 °. In this way or by means of a further suitable beam deflection, the central beam axes of all three beam fans 19, 26, 27 incident on the product strip enclose an angle of 120 ° with respect to one another.

As can be seen better in fig. 2, the

deflection elements

14, 24 and 25 are arranged in the beam path 16 such that all of the beam fans 19, 26, 27 incident on the product strip touch the product strip 11 at the same axial position MP of the product strip, so that the beam fans 19, 26, 27 incident on the product strip alternately overlap and produce a laser line 21 which is closed on itself and completely surrounds the product strip 11 through 360 °. The laser line 21, which is wound around the product strip 11 at 360 °, opens a plane that intersects the central longitudinal axis of the product strip 11 at point MP.

The laser line 21 which runs around the product strip 11 on its surface is recorded by means of optical triangulation. For this purpose, a plurality of

photosensitive elements

29, 30, 31 are arranged around the product strip, see fig. 1. The light-

sensitive elements

29, 30, 31 are in particular imaging sensors which convert light incident on the light-

sensitive elements

29, 30, 31 into electrical signals which contain image information and are evaluated by an electronic evaluation unit. Advantageously, a respective

light sensor

29, 30, 31 is associated with each incident light fan or light beam 19, 26, 27.

The measuring principle used for laser triangulation of the incident light fan or light beam 19 and the corresponding light-sensitive element 29 is explained below with reference to fig. 2. The same applies to the triangulation system of the further light-

sensitive elements

30, 31 with respect to the respective incident light fan or light beam 26, 27.

A laser line or a laser fan, which is very thin in the strip direction, is directed onto the product strip 11 by means of the laser source 12 as described above. The incident light beams or light fans 16, 19 advantageously fall perpendicularly onto the surface of the product strip 11 in a view transverse thereto (see fig. 2). The light sensitive elements 29 are arranged in this view such that the optical axis of light emerging from the surface of the product web 11 encloses a triangulation angle α with the optical axis of light incident on the surface of the product web 11. The triangulation angle α is advantageously in the range between 10 ° and 80 °, further advantageously between 20 ° and 70 °, still further advantageously between 30 ° and 60 ° and optimally between 40 ° and 50 °. Based on the triangulation angle α, the surface structure of the product strip mirrored in the corresponding course of the laser line 21 is shaped on the photosensitive element 29 and can be known computationally. In other words, the height information is obtained by capturing an image of the projected laser line 21 at a defined angle, i.e. the triangulation angle α, by means of the optical device or lens 32 and the imaging sensor 29 (see fig. 5). In this way, a measurement accuracy or measurement resolution is achieved for diameter measurements of better than 0.1mm, for example 0.01 mm.

Each light-sensitive element 29-31 is advantageously assigned a respective lens 32-34, see fig. 1. Each lens 32-34 has at least one, and preferably a plurality of optical lenses as is conventional. Each light-sensitive element 29-31 forms a respective camera 35-37 with the associated lens 32-34. The cameras 35-37 are arranged such that the laser line 21 is on the surface of the product strip 11 at the focus of the corresponding lens 32-34, so that the laser line 21 is clearly shaped onto the light sensitive elements 29-31. One or more of the cameras 35 to 37 may advantageously be arranged such that their optical axes each extend horizontally, as can be seen in fig. 1.

One or more beam deflecting elements 41-49 are advantageously arranged between the product strip 11 and each camera 35-37. The cameras 35 to 37 can thus be arranged optimally as a function of the installation space provided, so that measuring modules 50, 51 (see fig. 7) can be obtained which are as compact and optimally adapted to the respective installation situation as possible. The beam deflecting elements 41-49 may be or comprise mirrors and/or prisms, for example.

The outgoing light path 38 relative to the light sensitive element 29 is exemplarily described below. Similar considerations apply to the further outgoing

light paths

39, 40 with respect to the light-

sensitive elements

30, 31, respectively.

In the exit beam path 38 to the light sensor 29, three

beam deflection elements

41, 42, 43 are arranged in the embodiment according to fig. 1. Embodiments with one, two or more than three beam-deflecting elements in each outgoing light path 38-40 are contemplated.

Starting from the surface of the product strand 11, a first beam deflection element 41 may be provided, which deflects the beam 38 emerging at the triangulation angle α, for example, in such a way that the deflected beam 52 extends at an angle of between 75 ° and 105 °, for example at 90 °, relative to the strand axis. This can best be seen in fig. 4.

The light beam 52 deflected by the first beam-deflecting element 41 is deflected by at least one, here two, further beam-deflecting

elements

42, 43 in such a way that the outgoing light path 38 finally enters the camera 35. The total deflection by the at least one further beam-deflecting

element

42, 43 is advantageously at least 90 ° and for example 135 ° or even 180 ° as in the case of the light-sensitive element 31.

The light-

sensitive elements

29, 30, 31 are advantageously arranged at the same angular spacing relative to one another, in a preferred case three light-

sensitive elements

29, 30, 31 being arranged offset by 120 ° in each case around the product web 11. This is schematically shown in fig. 6. In other words, each

photosensitive element

29, 30, 31 covers an angular range of 120 ° in the circumferential direction of the product web 11, or 360 °/n in the case of n

photosensitive elements

29, 30, 31.

When one or more beam-deflecting elements 41-49 are arranged in the respective outgoing light path 38-40 between the product web 11 and the respective photosensitive element 29-31, the outgoing light paths 38-40 are advantageously arranged at the same angular spacing relative to one another around the product web 11. In this case, they may be arranged offset based on the light deflecting elements 41 to 49, not depending on the angular pitch of the light sensitive elements 29 to 31 as follows.

As described above, the beam path from the laser source 12 is deflected by the plurality of

mirrors

14, 24, 25, 41 to 49 as far as the imagers 29 to 31, so that the

individual components

12, 29 to 31 can be optimally positioned.

Thus, by combining the three laser lines 21 here, each over a 120 ° circumference of the product strip 11 (typically n laser lines each around a 360 °/n circumference of the product strip 11), a completely three-dimensional 360 ° profile of the product strip 11 surface, i.e. around the total circumference of the product strip 11, is obtained.

The measuring device 10 is advantageously enclosed by a housing 53 and thus forms the measuring

modules

50, 51. Fig. 7 shows the situation for a double strip machine for parallel processing of two endless product strips 11. In this case, two measuring

modules

50, 51 are advantageously provided, i.e. a

separate measuring module

50, 51 is provided for each product strip 11. The measuring

modules

50, 51 can advantageously be constructed to be identical. The housing 53 of each measuring

module

50, 51 advantageously has through-

openings

54, 55 opposite one another for the through-guiding of the product strand 11, which is only schematically illustrated in fig. 7, through the housing 53 and thus through the measuring device 10. Only the rear through-opening 55 in the rear wall of the housing 53 is schematically shown in fig. 7 for the measuring module 50.

The arrangement of the through

openings

54, 55 in the housing 53 may be asymmetrical. In particular, the through-

openings

54, 55 can be arranged at a significantly smaller distance d from the

nearest housing edge

56 or 57 or housing wall 58 than any other housing edge or housing wall. Particularly advantageously, the distance D is at most half as large as the distance D between two bars in a double-bar machine. In this case, it is possible to use correspondingly constructed measuring modules which are arranged only at 180 ° relative to one another in a rotating manner, as is shown in fig. 7.

Fig. 8 schematically shows a rod-forming unit 81 of a rod-forming machine 83 of the tobacco processing industry with a measuring device 10 integrated therein. In the case of a tobacco rod maker 83 as in fig. 8, the rod making unit 81 is usually preceded by a dispensing unit 84. In another embodiment, it may relate to a filter rod forming unit 81, for example in the form of a filter tow preparation unit, in a filter rod maker 83. In another embodiment, it may relate to the filter segment assembly section 81 of a multi-segment filter rod-making machine 83. Such a slivering machine 83 and slivering unit 81 are sufficiently known and therefore a detailed description is omitted here. The measuring device 10 described above is integrated into the rod-forming unit 81 or rod-forming machine 83 and is therefore produced.

The measuring device 10 or the measuring module 50 is advantageously located in the rod-forming unit in the rod-advancing direction between a wrapping device 59 for wrapping the material rod with a wrapping tape, for example paper, and a cutting device 60 for continuously cutting the endless rod 11 into individual rod-shaped elements.

In the following, the arrangement of the measurement data in the measurement module 50 and further data processing are explained with reference to fig. 9.

The measuring module 50, as described above, comprises at least three light-sensitive or imaging sensors 29 to 31, which are arranged, for example, offset by 120 ° in each case around the product web 11. Each sensor 29 to 31 can be assigned a controller 61, for example in the form of an FPGA and/or a microcontroller, which can be used, in particular, for pre-evaluation and/or data compression. The data of the individual image sensor modules are transmitted via corresponding fast data connections 62 to a main control or data integration unit 63, for example also to an FPGA and/or a microcontroller. The sensor module 50 now supplies the profile values of the product strip 11 via the fast data connection 64 to a following evaluation unit 65, for example as a polar coordinate system or cartesian coordinate system.

In the arithmetic unit 66, which receives the sensor data from the sensor module 50, the quality values, special features and/or service data of the strip are generated from the sensor data in conjunction with the machine controller 67. These data are advantageously used for machine visualization and/or parameterization 68 and/or controllers and/or actuators for the manufacturing process, in particular by means of an actuator 69 for the adjustment and/or an actuator 70 for product selection or product waste (produktausschus), in order to achieve a higher product quality and a more efficient running time of the manufacturing machine. The main control or data synthesis unit 63 and/or the arithmetic unit 66 according to fig. 9 advantageously form a digital evaluation device 73 according to the claims.

Via corresponding data channels, the information can also be used for data collection and analysis in the superordinate data collector 71 and for controlling and/or regulating the upstream machine 72, in order to also increase the quality of the components to be supplied to the production machine there.

In an alternative embodiment, the computing power of the main control or data integration unit 63 is sufficiently large, in which embodiment the quality values, special features and/or service data of the bars can also be calculated there from the sensor data and made available to the visualization device 68 and further processing devices via suitable data channels.

An advantageous application of the measuring device 10 is for measuring quality values, characteristics and/or service data of individual segments in endlessly repeating multi-segment rod segments of a product strip 11. This is explained below with respect to fig. 10.

The endless processed product strip is formed from continuously repeating rod segments. Each rod segment (Stabschnitt) corresponds to a rod after the strip of articles 11 has been cut into individual rods by means of the cutting device 60 (see fig. 8). The rod section can therefore also be referred to as a rod in a simplified manner.

Each rod or rod section Sn is in turn assembled in this application from the same sequence of segments T1, T2, T3. In the present case, each rod has three segments T1, T2, T3, wherein each rod may have more or less than three segments. This therefore relates to multi-segment rods.

As is clear from fig. 10, the scanning rate of the measuring device is sufficiently high that a circumferential profile P of the product web 11 can be measured at least for each segment. In other words, the spacing a between the two measurement profiles P, obtained by the scan rate, is advantageously less than or equal to the shortest segment length in the product web 11, here less than or equal to the length of segment T2. In a practical embodiment, the pitch between two profile scans P should be at most 20mm, advantageously at most 10mm, further advantageously at most 5mm, for example 3 mm. The scan rate is in practice advantageously at least 500 profile sweeps P per second, advantageously at least 1000 profile sweeps P per second, further advantageously at least 2000 profile sweeps P per second, yet further advantageously at least 3000 profile sweeps P per second and for example at 4000 profile sweeps P per second.

It is also apparent from fig. 10 that the measurement or scanning of the circumferential profile P of the product web 11 is advantageously carried out synchronously with the division of the product web into bars and/or bar segments and/or synchronously with the production speed, i.e. the scanning rate is advantageously adapted to the production speed such that the bars or bar segments are always measured at the same axial position. This improves the similarity of the measurement results.

From the known perimeter profiles, different quality data, characteristics and service values of the product strip 11 can be known.

The quality values are advantageously calculated and specified for each rod, for each segment and/or as an average value for the production. Examples of this are: the diameter and circumference of the article strand 11; ovality; out-of-roundness factors, such as the standard deviation of the strip profile radii; the position of the seam of the wrapping strip, for example as an angle.

In general, one or more standard deviations (or differences) of one or more of the above parameters may contain meaningful information and may be known for further processing. If, for example, an average value is formed from individual values, it is advantageous to specify the standard deviation at the same time, for example, in order to obtain early notice of production and imminent defects that have become unsettled, for example, as a result of machine contamination, and to be able to react to this in a timely manner.

The features of the product strip to be detected are, in particular, features which can be noted as defects in the product, i.e. in the cut strip. The product with the defects is then advantageously selected or removed from production. The features of this form are for example: profile defects on sub-blocks and/or on individual segments of a strip; wrapping the bonding part of the strip in the direction of the endless strip; a bond site defect at a bond joint on a sub-block of the strip; foreign matter on the bar adheres.

Service information is important for machine fitters, service personnel and machine operators to obtain instructions about reliable production and to be able to intervene in the production process, possibly corrected. The service data in this form is, for example: vibrating the strip; uneven longitudinal seams of the wrapping strip, for example as a standard deviation via production; a contour region diagram; 3D region map.

Examples of profile area maps for a scan are shown in figures 11 and 12. A plot of the profile region in a polar coordinate system is shown in fig. 11. It is clearly recognizable that the contour and thus the product strip exhibit a defective flattening in the range between 0 ° and 120 °. The same circumference profile in the cartesian coordinate system is applied in fig. 12 as a radius with respect to the angle or as a function of the angle. It is also evident here that a defective flattening of the profile and thus of the product strip in the range between 0 ° and 120 ° is possible.

An example for a 3D contour plot is shown in fig. 13, which is assembled from a plurality of individual contour plots according to fig. 11 one behind the other in the production direction. The figure here shows only a part of the profile corresponding to the image sensor. It is clear that a full 360 profile can be shown as well. In this image, a thickened portion in the rear region can be identified, which may be a single segment of greater thickness, for example. On the front edge, longitudinal folds can be seen in the bright areas.

Instead of laser line 21, light lines or light-dark edges, in particular composed of structured light, can also be used.

Instead of a single circumferential laser line, several light lines can also be projected onto the product strip at defined axial spacings, so that several profiles can be measured simultaneously per image recording.

Claims

1. Optical measuring device (10) for the determination of at least one characteristic, quality value and/or service data of an endlessly processed product rod (11) of the tobacco processing industry on the basis of triangulation, comprising:

-at least one light source (12) for generating a plurality of incident light paths (16) falling onto a surface of the article band (11) around its circumference;

-at least three light sensitive elements (29-31) arranged in a triangulation system with respect to the incident light path (16);

-digital evaluation means (73) arranged for learning the 3-dimensional surface profile of the product strip (11) from the measurement signals transmitted by the light-sensitive elements (29-31),

characterized in that the optical measuring device (10) has at least one light deflection element (14, 17, 24, 25) between the light source (12) and the product web (11) for deflecting at least one incident light path (16) and/or between the product web (11) and at least one light sensitive element (29-31) for deflecting at least one outgoing light path (38-40).

2. Optical measuring device according to claim 1, characterized in that the number of light sources (12) is smaller than the number of light-sensitive elements (29-31) and/or that the measuring device (10) has exactly one light source (12), in particular a laser light source.

3. Optical measuring device according to one of the preceding claims, characterized in that the at least one light source (12) generates a main radiation fan (15), wherein a part (19) of the main radiation fan (15) falls onto the product strip (11) and another part (22, 23) of the main radiation fan passes by the product strip (11) on one or both sides of it and is directed onto the product strip (11) with at least one light deflecting element (24, 25) after passing the product strip (11).

4. Optical measuring device according to any of the preceding claims, characterized in that the optical measuring device (10) has at least or exactly three incident light paths (16) arranged around the circumference of the article band (11).

5. Optical measuring device according to any of the preceding claims, characterized in that a collimating lens (17) is arranged in the incident light path (16).

6. Optical measuring device according to one of the preceding claims, characterized in that at least one light deflecting element (41-43; 44-46; 47-49) is arranged in each outgoing light path (38, 39, 40).

7. Optical measuring device according to any one of the preceding claims, characterized in that the evaluation device (73) is arranged for learning from the 3-dimensional surface profile one or more of the following quality values or characteristics or service data of the product strip (11):

-a diameter;

-a perimeter;

-ovality;

-out-of-roundness factor;

-the stitch position of the wrapping strip;

-a standard deviation of one or more of the aforementioned parameters;

-a profile defect;

-a bonding site of the wrapping strip;

-a bond site defect of the bond line;

-foreign body attachment;

-the strip is vibrated;

-a non-stationary longitudinal seam wrapping the strip;

-a profile area map;

-3D zone map.

8. Optical measuring device according to one of the preceding claims, characterized in that the light-sensitive elements (29-31) are position-sensitive imaging sensors, in particular CMOS sensors, and/or the incident light path (16) falls vertically onto the product strip and/or the drawing planes of the light-sensitive elements (29-31) are arranged inclined with respect to the corresponding optical axis.

9. Optical measuring device according to any of the preceding claims, characterized in that the scanning rate of the measuring device (10) is selected such that the spacing a between two measuring profiles P is smaller than or equal to the shortest segment length in the product strip (11).

10. Optical measuring device according to one of the preceding claims, characterized in that a controller (61), in particular an FPGA and/or a microprocessor, is assigned to each photosensitive element (29-31) or to all photosensitive elements (29-31) for preprocessing, pre-evaluating and/or data compression of the signals of the photosensitive elements (29-31).

11. Optical measuring device according to claim 10, characterized in that the data of the controller (61) or of all controllers (61) are sent to a main control and/or data integration unit (63), in particular an FPGA and/or a microprocessor, for further processing.

12. Measuring module (50, 51) comprising an optical measuring device (10) according to any one of the preceding claims and a housing (53) enclosing the measuring device (10), the housing having a through-opening (54, 55) for the through-guiding of the product strip (11) through the measuring module (50, 51).

13. Measuring module (50, 51) according to claim 12, characterized in that the distance D of the through-opening with respect to the nearest housing edge (56) is smaller than or equal to half the distance D of two product strips (11) to be processed in a double strip machine.

14. Use of an optical measuring device (10) according to any of the preceding claims for measuring quality values, characteristics and/or service data of individual segments T1, T2, T3 in an endlessly repeating multi-segment rod segment Sn of a product strip (11).

15. Method for the optical measurement of quality values, characteristics and/or service data of an endless processed product rod (11) of the tobacco processing industry by means of an optical measuring device (10) according to one of claims 1 to 11, characterized in that the measurement is carried out synchronously with the division of the product rod (11) into rod Sn and/or rod segments T1, T2, T3 and/or synchronously with the production speed.