CN108685161B

CN108685161B - Method and system for determining the origin trajectory of products of the tobacco processing industry, cigarette inspection station

Info

Publication number: CN108685161B
Application number: CN201810325641.2A
Authority: CN
Inventors: S.波西; K.梅纳格; S.阿克布恩
Original assignee: Sodim SAS
Current assignee: Kolber Technical Instrument Co ltd
Priority date: 2017-04-12
Filing date: 2018-04-12
Publication date: 2022-03-25
Anticipated expiration: 2038-04-12
Also published as: EP3387919A1; KR20180115230A; EP3387919B1; CN108685161A; KR102624345B1

Abstract

The invention relates to a method and a system for determining a source trajectory of products of the tobacco processing industry, and to a cigarette inspection station. A single length filter cigarette produced in a cigarette manufacturing machine having a plurality of tracks is received in a rotary device and rotated about a rotation axis parallel to the longitudinal axis of the cigarette, wherein during rotation of the cigarette held in the rotary device, the seam of the tipping paper and the wrapper of the cigarette is optically detected, the origin track of the cigarette being determined from the results of the optical detection. According to the invention, the optical detection comprises distance measurements performed using at least one first distance measuring device and at least one second distance measuring device, the at least one first distance measuring device being positioned and oriented so as to generate at least one first raw data signal representative of the distance to the tipping paper of the cigarette, and the at least one second distance measuring device being positioned and oriented so as to generate at least one second raw data signal representative of the distance to the tipping paper of the cigarette.

Description

Method and system for determining the origin trajectory of products of the tobacco processing industry, cigarette inspection station

Technical Field

The invention relates to a method and a system for determining a source trajectory of products of the tobacco processing industry, and to a cigarette inspection unit. A single length filter cigarette produced in a cigarette manufacturing machine having a plurality of tracks is received in a rotary device and rotated about a rotation axis parallel to the longitudinal axis of the cigarette, wherein a seam of a wrapper and a tipping paper of the cigarette is optically detected during rotation of the cigarette held in the rotary device, wherein the origin track of the cigarette is determined from the result of the optical detection.

Background

It is known in the art to manufacture filter cigarettes in a cigarette manufacturing machine having a plurality of tracks, for example dual tracks. Such machines may have multiple tracks in the unit for preparing the endless tobacco rod and in the unit for producing the endless filter rod. The endless tobacco rods are each wrapped in an endless wrapper paper band which is wrapped around the tobacco within the tobacco rod and closed by an applied adhesive which joins the wrapper to itself in the overlapping region of the seam constituting the wrapper paper band. The filter rods may or may not be wrapped in the filter paper band as such.

After the tobacco rod and the filter rod are cut from the endless tobacco rod and the filter rod, they are brought together into a filter tipping unit, forming a common mass flow of cigarettes. In a typical arrangement, a double length filter rod is inserted between two single length tobacco rods. The tipping paper with the adhesive applied end portions is wrapped around the filter rod and simultaneously overlaps adjacent portions of two adjacent tobacco rods, thereby providing a stable connection between the filter rod and the tobacco rods. To complete the wrapping, the adhesive portion of the tipping paper is applied to the opposite end of the tipping paper. In the next step, the central double length filter rod is cut in the middle, thereby forming two single length filter cigarettes.

Frequently, quality control is performed, which can be used to detect problems in the different units of the cigarette manufacturing machine, which may be specific to its single track. One such quality control method is to form a mass flow and an object. These sample cigarettes were subjected to further testing. In order to attribute the results to different tracks from different units, it is necessary to determine the source track of the sample cigarette being tested.

EP 2183985B 1 discloses a technique for determining a source trajectory in a cigarette manufacturing machine having a plurality of trajectories, wherein a sample cigarette is received by a rotating member for rotating the cigarette relative to a detection member arranged to detect radiation from the cigarette and generate a signal indicative of the detected radiation, and a processing member is included arranged to process the signal generated by the detection member to identify shadows cast by the tipping paper seam and by the tipping paper seam, and wherein the processing member is arranged to determine a difference between a circumferential position of the shadow cast by the tipping paper seam and a circumferential position of the shadow cast by the tipping paper seam, and to generate a signal indicative of the source trajectory of the cigarette in dependence thereon. The technique disclosed in EP 2183985B 1 is based on the fact that: the seam will cast a shadow when illuminated by light at an oblique angle from one side. The signal processing includes detecting the amplitude and position of the dip in the signal of the light detected by the detecting means and comparing the magnitude of the dip with a predetermined threshold. Furthermore, a timer is used during rotation of the cigarette to detect the time difference for the occurrence of a sag in the wrapper seam and the tipping paper seam, and this time difference is then compared with a predetermined threshold value for the time difference.

Disclosure of Invention

The object of the invention is to improve the technique, in particular with regard to the reliability of the detection of the joint.

This object is achieved by a method for determining a source trajectory for products of the tobacco processing industry, wherein single length filter cigarettes produced in a cigarette manufacturing machine having a plurality of trajectories are received by a rotating device (in particular a rotating chuck) and rotated about a rotation axis parallel to a longitudinal axis of the cigarettes, wherein during rotation of the cigarettes held in the rotating device, optical detection of the seams of the tipping papers and of the cigarettes is carried out, wherein the source trajectory of the cigarettes is determined from the results of the optical detection, wherein the optical detection comprises distance measurements performed using at least one first distance measuring device and at least one second distance measuring device, wherein the at least one first distance measuring device is positioned and oriented so as to generate at least one first raw data signal representing the distance to the tipping papers of the cigarettes, and the at least one second distance measuring device is positioned and oriented to produce at least one second raw data signal indicative of the distance to the tipping paper of the cigarette.

Although the technique described in EP 2183985B 1 can be perfected by improving the lighting conditions, including the use of a well-defined light source with a small light emitting area, the selection of an appropriate wavelength of the detected light and the improvement of the signal processing, it is affected by the fact that: paper seams can be poorly defined and, therefore, the shadows cast by the seams can vary in width and depth. In contrast, the present invention relies on optical distance measurement rather than shadow detection. Optical distance measuring devices with an accuracy in the micrometer range are available and the target area is virtually point-like, whereas in shadow detection techniques the field of view to be examined may be several millimeters long and wide. Thus, the optical distance measurement provides excellent resolution and therefore higher reliability in detecting the seam of the wrapper and the tipping paper.

When the cigarette is rotated, the paper seam will produce a step or spike in the distance measurement signal proportional to the thickness of the wrapper or tipping paper, which may range between 0.05 and 0.25 mm, depending on the type of wrapper or tipping paper used in each particular brand of cigarette. Such steps are much larger than the resolution of modern distance measuring devices and can therefore be easily detected with a good signal-to-noise ratio (SNR). One type of distance measuring device that may be used to implement the method of the present invention is a laser telemetry device.

Preferably, the at least one first raw data signal and/or the at least one second raw data signal are filtered using a high-frequency pass filter. This measure will filter out most deviations of the cigarette from the ideal cylindrical shape, but leave sharp spikes or step functions in place that are created by the paper seam. Furthermore, the at least one filtered first raw data signal and/or the at least one filtered second raw data signal are preferably denoised after having been filtered using a high-frequency pass filter, wherein the denoising is performed in particular using a median filter. The median filter removes extreme noise events by removing or reducing the residual noise in the signal by relying on the median value within a window of several data points. Depending on the relative size of the median filter window with respect to the width of the portion of the signal affected by the paper seam (which is also referred to as the paper seam signal), the paper seam signal in the signal may survive the median filter, or the residue of the median filter being modified such that signals above or below a predetermined threshold are not filtered out.

In an embodiment, a seam signal (in particular a peak or step function representing a paper seam) is detected within the raw data signal or the filtered raw data signal, in particular by detecting a signal amplitude exceeding a threshold range to a statistically significant extent, the threshold range being selected or calculated such that random fluctuations of the filtered raw data signal remain within the threshold range. With this method, statistically significant results of scene detection are reliably achieved. In a further embodiment, the wrapping direction of the seam is determined by the sign of the amplitude of the seam signal. Depending on the wrapping direction, the peak or step function representing the paper seam and thus constituting the paper seam signal will appear with a positive or negative sign to indicate a decrease or increase in the distance between the surface of the cigarette's wrapper or tipping paper and the distance measuring device. If the wrapper or tipping paper is wrapped in the same direction as the direction of rotation of the cigarette in the spin chuck, the distance will increase upon reaching the scene, whereas if the paper is wrapped in the opposite direction to the direction of rotation of the cigarette, the distance will suddenly decrease.

In further embodiments, an offset is determined between the positions of the wrapper seam and the tipping paper seam on the circumference of the cigarette, which is indicative of the source trajectory. This can be done by the relative position of the recording paper seam signal with respect to the time the tipping paper is on the wrapper and the position within the data signal corresponding to the position on the circumference of the cigarette. In performing the detection of the offset of the position, the offset of the first distance measuring device and the second distance measuring device in terms of their angular relationship with respect to the circumference of the cigarette must be corrected. For example, it may be necessary to offset the two distance measuring devices by 90 ° or 180 ° or still different angles relative to each other, due to the available space within the machine or cigarette inspection unit.

The object of the invention is also achieved by a system for determining a source trajectory of a product of the tobacco processing industry, the system comprising: a rotating device, in particular a rotating chuck, for receiving and rotating single length filter-tipped cigarettes produced in a cigarette manufacturing machine having a plurality of tracks about an axis of rotation parallel to the longitudinal axis of the cigarettes; an optical detection means for optically detecting a seam between a wrapping paper of a cigarette and a tipping paper; a controller and signal processing means for processing raw data signals of the optical detection means, wherein the optical detection means comprises at least one first distance measuring device and at least one second distance measuring device, wherein the at least one first distance measuring device is positioned and oriented so as to generate at least one first raw data signal representing the distance to the tipping paper of the cigarette and the at least one second distance measuring device is positioned and oriented so as to generate at least one second raw data signal representing the distance to the tipping paper of the cigarette. Preferably, the controller and the signal processing means are configured to perform the method of the invention described above.

The system of the invention thus comprises the same features, characteristics and advantages as the method of the invention described above. The controller and signal processing means may be implemented in one device, e.g. a programmable computer, or in several different devices interconnected for the transmission of commands and data.

In an embodiment, the at least one first distance measuring device and/or the at least one second distance measuring device comprises one or more laser telemetry units, thereby providing excellent resolution and reliability. In a further embodiment, the signal processing unit is configured to filter the at least one first raw data signal and/or the at least one second raw data signal using a high frequency pass filter, and in particular to de-noise the at least one first raw data signal and/or the at least one second raw data signal that has been high pass filtered, in particular using a median filter.

In a further embodiment, the signal processing unit is configured to detect a seam signal, in particular a peak or step function representing a paper seam, within the raw data signal or the filtered raw data signal, in particular by detecting a signal amplitude exceeding a threshold range to a statistically significant extent, the threshold range being selected or calculated such that random fluctuations of the filtered raw data signal remain within the threshold range.

In a further advantageous embodiment, the signal processing unit is configured to detect a wrapping direction of the seam by detecting a sign of an amplitude of the seam signal and/or is configured to detect an offset between positions of the wrapper seam and the tipping paper seam on a circumference of the cigarette, the offset being indicative of the source track.

The object of the invention is furthermore achieved by a cigarette inspection unit comprising the system of the invention described previously for determining the origin trajectory of products of the tobacco processing industry. The cigarette inspection unit thus embodies the same features, characteristics and advantages as the system of the invention and the method of the invention.

Other features of the invention will become apparent from the description of embodiments according to the invention and from the claims and the included drawings. Embodiments in accordance with the present invention can implement individual features or a combination of several features.

Drawings

Without limiting the general purpose of the invention, it is described below on the basis of exemplary embodiments, wherein reference is explicitly made to the attached drawings for a disclosure of all details according to the invention which are not explained in greater detail herein. The figures show:

figure 1 is a schematic representation of double length cigarettes from different tracks,

figure 2 is a schematic representation of a wrapper seam and a tipping paper seam on cigarettes from different source tracks,

figure 3 is a schematic representation of an embodiment of the system according to the invention,

FIG. 4 shows the measured signals from the system shown in FIG. 3 at various stages of signal processing, an

Figure 5 processed distance signals from various signals of a simple cigarette.

In the drawings, elements of the same or similar type or respectively corresponding parts are provided with the same reference numerals to prevent items from needing to be reintroduced.

Detailed Description

Figure 1 shows a schematic representation of a double length cigarette 10 from different tracks of a two track machine. These two tracks are named track a (ta) and track b (tb). The double length cigarette 10 is made up of a double length filter rod 14 in the middle and single length tobacco rods 12 on either side thereof, the single length tobacco rods 12 being attached to the filter rod 14 by tipping paper wrapped around the filter rod 14 and adjacent portions of the tobacco rod 12. Two double length cigarettes 10 from tracks TA and TB are depicted as being transported cross-axially in a transport direction 11. Double-length cigarette 10 is then cut along cutting plane 16 to form two single-length cigarettes 24, each oriented axially opposite one another. These two parts are named "front bar" (FR) and "rear bar" (RR). Thus, the four single-length cigarettes resulting from the cutting will have the orbital combinations FR-TA, RR-TA, FR-TB and RR-TB.

In a further subsequent step, the front or rear rod is reoriented so as to assume the same orientation as the other cigarettes.

Figure 2 shows a schematic representation of the wrapper seam and the tipping paper seam on cigarettes of different source tracks, four single length cigarettes 24 being numbered 1 to 4 and corresponding to the FR-TA, RR-TA, FR-TB and RR-TB rods of figure 1. The separated portion of figure 2 depicts a single length cigarette 24 and a wrapper seam 26 and its tipping paper seam 28, where the direction of overlap is indicated by using a solid line for the edge of the upper layer of paper and a dashed line for the hidden edge of the lower layer of paper at each seam. In addition, it can be seen that there is an offset between the wrapper seam 26 and the tipping paper seam 28 of each single length cigarette 24, which may also indicate the origin trajectory of the cigarette 24.

Above the middle portion of figure 2, the end portion of the tobacco rod of the single length cigarette 24 is shown, illustrating either a clockwise or counter-clockwise packing direction. Below the separating portion of fig. 2, the transition between the tobacco rod and the filter portion of the cigarette 24 is also shown, indicating the direction of wrapping of the tipping paper. The packing orientation of the four cigarettes 24 can be summarized in the following table:

numbering	Direction of overlapping of wrapping paper	Direction of overlapping tipping paper
			1	+	-
2	-	+
			3	-	-
4	+	+

This shows that the combinations achievable by the pack orientation are sufficient to identify up to four cigarettes.

It can be extended to even more tracks when seam alignment or seam offset is considered, as shown in the following table:

numbering	Seam alignment	Direction of overlapping of wrapping paper	Direction of overlapping tipping paper
				1	0	+	+
2	0	+	-
				3	0	-	+
4	0	-	-
				5	1	+	+
6	1	+	-
				7	1	-	+
8	1	-	-

It can be extended more in case there are more available seam offset values.

Fig. 3 shows a schematic representation of an embodiment of the system according to the invention, in this case as part of a cigarette inspection unit 32. The technique used according to the invention is based on two distance measuring devices, in particular and by way of example, two or more laser telemetry heads 36, 38, which accurately measure the distance between the heads on the surface of the cigarette 24, which in turn is held in position and rotated about its longitudinal axis by a rotating device, in this case a rotating chuck 34. A first telemetry head, a tobacco laser telemetry head 36, is guided at the surface of the wrapper 25 of the cigarette 24, while a second telemetry head, a filter laser telemetry head 38, is guided at the surface of the tipping paper 27 of the cigarette 24. This is depicted in the lower portion of fig. 3 in a cross-sectional view through the tobacco portion of the cigarette 24, along with an indication for the direction of rotation 35 and an axis of rotation 35', the axis of rotation 35' ideally coinciding with the center of the cigarette 24.

During rotation of cigarette 24 on or in spin chuck 34, laser beams emitted from laser telemetry heads 36, 38 will encounter wrapper seam 26 and tipping paper seam 28, respectively. While the spin chuck 34 is rotating, both laser telemetry heads 36, 38 measure changes in distance between the respective

laser telemetry head

36, 38 and the surface of the cigarette 24 accurately and in real time. Laser telemetry heads 36, 38 will each generate a distance signal containing signals of varying distances encountered in traversing

paper seams

26, 28 due to the thickness of wrapper paper 25 and tipping paper 27, respectively. Depending on the direction of change, the system detects whether it is packing clockwise or counter-clockwise. Since the overlapping portions of filter and tobacco are measured simultaneously, the system is able to give the relative angular difference between the two seams.

The raw data signals generated by tobacco laser telemetry head 36 and filter laser telemetry head 38 are transmitted to signal processing unit 40 and signal processed within signal processing unit 40, as will be shown in fig. 4 and 5.

Since a wide variety of cigarette lengths exist on the market, tobacco laser telemetry head 36 is preferably designed to be adjustable in height. The filter laser telemetry head 38 may be held in a fixed position to measure directly below the area of the ventilation holes or perforations 30 that may be present in the tipping paper 27 to prevent any unwanted signal changes.

Fig. 4 a) to 4 d) show the measurement signals from the system shown in fig. 3 in various stages of signal processing. In all cases, the vertical axis is in millimeters and shows the deviation in distance between the surface of cigarette 24 and the observation laser telemetry head, which in this case may be tobacco laser telemetry head 36 or filter laser telemetry head 38. The horizontal axis indicates the number of each measurement period. In this case at a resolution of about 0.76 ° in each data point, or every 0.05 mm over the circumference of the cigarette.

The surface of cigarette 24 is typically irregular, and rotation creates additional noise to the measurement signals emitted by laser telemetry heads 36, 38. Such irregularities are clearly visible in the original data signal 50 shown in fig. 4 a). Since the signal 50 repeats itself, it is apparent that the cigarette 24 being tested has rotated more than twice. Clearly visible in the raw data signal 50 are the narrow peaks that make up the seam signal 52. This measurement is made because the seam signals 52 have a positive sign, that is they represent peaks having increasing values for the distance between the surface of the cigarette 24 and the laser telemetry head, which means that the wrapping direction of the paper is such that the laser beam first encounters the upper layer on the overlapping region of the seam and then the end of the seam, creating a step in the signal with an amplitude slightly less than 0.2 mm, 0.2 mm corresponding to the thickness of the paper. Furthermore, it can be seen that although the overall trend of the original distance signal 50 is increasing, the distance signal decreases sharply in the data point immediately preceding the seam signal 52. This reduction before the sudden increase is due to the

seam

26, 28 being pushed out by the tobacco or filter material within the wrapper 25 or tipping paper 27. Conversely, if the wrapping direction is reversed relative to the direction of rotation of the cigarette, encountering such a scenario would suddenly decrease the distance to the laser telemetry head, thereby creating a negative peak in the raw data signal 50.

The raw data signal 50 may be processed to isolate the seam signal 52. A suitable filter for eliminating variations in the raw data signal 50 caused by irregularities in the cigarette itself is a high frequency pass filter which eliminates low frequency portions of the raw data signal 50. This can be done by not using any means such as performing a fast fourier transform on the signal or simply by computing all data points n of the raw data signal 50:

wherein the content of the first and second substances,Y _highpassandY _rawrespectively representing high-pass filtered data points and raw data signal points. This high-pass filtering results in a high-pass filtered signal 60 shown in fig. 4 b). The high pass filtered signal 60 exhibits a fairly stable baseline around zero and a significant seam signal 62 indicating a paper thickness of about 0.18 mm.

Although the high-pass filtered signal 60 itself has been adapted to detect the location and design of the seam signal 62 embedded therein, another data signal processing step may advantageously be applied to the high-pass filtered signal 60 in order to achieve better noise reduction or smoothing of the signal. This can be achieved by using a median filter. The result of applying the median filter with a window size of three data points is shown in fig. 4 c) as the smoothed signal 70 with the seam signal 72. The median filter operates such that the median value is selected from three different values of the data points present in the future window, i.e. the highest and lowest values are discarded. The noise in the baseline signal is significantly reduced. Thus, the seam signal 72 in the signal 70 can be identified with very high confidence.

In a further step shown in fig. 4 d), the seam signal 72 is identified by applying a bilateral threshold around the baseline signal 70 according to the following formula:

threshold value =μ± cσ

WhereinμIs the average of the signal 70 after the median filtering step, andσis the standard deviation of the signal 70 after median filtering. Constant numbercMay be chosen appropriately to eliminate false positives and may range between 2 and 4. In the case of fig. 4 d), the threshold is 2.8 above and below the average value of the signal 70σOr standard deviation. Each peak in the signal 70 that exceeds the bilateral threshold is considered a seam detection. If the system finds that more peaks are detected than expected, the peak with the highest absolute value of amplitude may be prioritized.

The method of the present invention can be performed independently of the brand or size of the cigarette, as advantageously the cigarette 24 can be rotated more than once so that the seam signal 72 is encountered more than once. Since the seam signal 72 will thus be recognized multiple times, subsequent occurrences of the seam signal 72 indicate a complete rotation of the cigarette 24.

The results of the seam signal recognition are shown in fig. 5 a) and 5 b). In this case, the raw data signals of both tobacco laser telemetry head 36 and filter laser telemetry head 38 have been subjected to high frequency pass filtering and are shown superimposed on each other in fig. 5 a). The packing direction was the same in both cases, as indicated by the negative amplitude of the peaks. The seam signal 76 represents a wrapper seam signal and the seam signal 78 represents a wrapper seam signal.

The system provides peak locations for tobacco laser telemetry head 36 at locations 32 and 501 with an amplitude of approximately-114 μm and a signal-to-noise ratio of 22.5dB, while filter laser telemetry head 38 observes peaks at locations 372 and 841 with an amplitude of approximately-140 μm and a signal-to-noise ratio of 23.5 dB. The system that generates the two corresponding signals employs a tobacco laser telemetry head 36 and a filter laser telemetry head 38 that are at 90 ° angles to each other relative to the cigarette 24 due to mechanical constraints. This 90 ° offset between laser telemetry heads 36, 38 must be taken into account when calculating the offset between wrapper seam 26 and wrapper seam 28.

Shifting or correspondingly phase shifting between the two seams 26, 28AThe calculation in degrees is:

wherein the content of the first and second substances,Trepresents the average of two cycles, anψ _tpAndψ _wpthe positions of the tipping paper seam 28 and the wrapper paper seam 26 are shown, each in terms of the number of sampling points. 90 ° offset between laser telemetry heads 36, 38 is by plus +T/4Is counted in.

When using the above-mentioned position of the peak in FIG. 5 a), the average period of 469 data points is calculatedTAnd is inψ _tp=372 andψ _wpin the case of =32, a minimum angle of 9 ° and a maximum angle of 351 ° between the wrapper seam 26 and the wrapper seam 28 are calculated. This is shown in fig. 5 b), but the figure does not account for the 90 ° offset between laser telemetry heads 36, 38.

The result of the paper seam determination is that the two seams are oriented in the same wrap direction, producing a negative sign seam signal, and that there is a 9 ° difference or phase shift between the two paper seams, with the tipping paper seam 28 preceding the tipping paper seam 26 in the direction of rotation 35 of the cigarette 24 within the rotating chuck 34.

All the indicated properties, including those taken alone from the drawings and the individual properties disclosed in connection with the other properties, are deemed to be essential to the invention, either alone or in combination. Embodiments in accordance with the present invention may be realized by individual features or combinations of several features. Features which are combined with the word "particularly" or "in particular" are to be considered preferred embodiments.

List of reference numerals

10 double length cigarette

11 cross axial conveying direction

12 tobacco rod

14 filter tip rod

16 cutting plane

18 cross axial conveying direction

20 end segment

22 filter end section

24 single-length cigarette

25 packaging paper

26 paper wrapper seam

27 tipping paper

28 tipping paper seam

30 perforation

32 inspection unit

34 rotating chuck

35 direction of rotation

35' axis of rotation

36 tobacco laser telemetry head

38 filter tip laser telemetry head

40 Signal processing unit

50 raw data signal

52 seam signal in raw data signal

60 high-pass filtered signal

62 seam signal

70 high-pass filtering and median filtering of the signal

72 seam signal

73 seam position in the filtered signal

Upper 74 threshold value

75 lower threshold value

76 wrapper seaming signal

78 tipping paper seam signal

TA, TB source track

FR front bar

RR rear bar.

Claims

1. Method for determining a track of origin (TA, TB, FR-TA, FR-TB, RR-TA, RR-TB) of products of the tobacco processing industry, wherein a single length filter cigarette (24) produced in a cigarette manufacturing machine having a plurality of tracks (TA, TB) is received by a rotating device (34) and rotated about a rotation axis (35') parallel to the longitudinal axis of the cigarette (24), wherein during the rotation of the cigarette (24) held in the rotating device (34) the wrapper seams (26, 28) of the wrapper (25, 27) of the cigarette (24) and of the tipping paper (27) are optically detected, wherein the track of origin (TA, TB, FR-TA, FR-TB, RR-TB) of the cigarette (24) is determined from the results of the optical detection, RR-TA, RR-TB), characterized in that the optical detection comprises distance measurements performed using at least one first distance measuring device (36) and at least one second distance measuring device (38), wherein the at least one first distance measuring device (36) is positioned and oriented so as to generate at least one first raw data signal representing the distance to the wrapper (25) of the cigarette (24) and the at least one second distance measuring device (38) is positioned and oriented so as to generate at least one second raw data signal representing the distance to the tipping paper (27) of the cigarette (24).

2. Method according to claim 1, characterized in that the at least one first raw data signal and/or the at least one second raw data signal are filtered using a high frequency pass filter.

3. Method according to claim 2, characterized in that the at least one filtered first raw data signal and/or the at least one filtered second raw data signal is noise reduced after having been filtered using a high frequency pass filter.

4. The method of claim 3, wherein the noise reduction is performed using a median filter.

5. The method of claim 1, wherein a seam signal (62, 72) is detected within the raw data signal or the filtered raw data signal.

6. The method of claim 5, wherein the seam signal (62, 72) is a peak or step function representing a paper seam.

7. The method according to claim 5, characterized by detecting the seam signal (62, 72) within the raw or filtered raw data signal by detecting signal amplitudes that exceed a threshold range (74, 75) to a statistically significant extent, the threshold range (74, 75) being selected or calculated such that random fluctuations of the filtered raw data signal remain within the threshold range.

8. A method according to claim 1, wherein the wrapping direction of the wrapper seam (26) and the wrapper seam (28) is determined by the sign of the amplitude of the seam signal (62, 72).

9. A method according to claim 1, wherein an offset is determined between the positions of the wrapper seam (26) and the tipping paper seam (28) on the circumference of the cigarette (24), the offset being indicative of a source track (TA, TB, FR-TA, FR-TB, RR-TA, RR-TB).

10. A system for determining a source trajectory (TA, TB, FR-TA, FR-TB, RR-TA, RR-TB) of a product of the tobacco processing industry, the system comprising: a rotating device (34) for receiving and rotating a single length filter cigarette (24) produced in a cigarette manufacturing machine having a plurality of tracks (TA, TB) about a rotation axis (35') parallel to the longitudinal axis of the cigarette (24); -optical detection means for optically detecting a wrapper seam (26) and a tipping paper seam (28) of a wrapper (25) and a tipping paper (27) of the cigarette (24); -a controller and signal processing unit (40) for processing raw data signals (50) of the optical detection means, characterized in that the optical detection means comprise at least one first distance measuring device (36) and at least one second distance measuring device (38), wherein the at least one first distance measuring device (36) is positioned and oriented so as to generate at least one first raw data signal representing the distance to the tipping paper (25) of the cigarette (24) and the at least one second distance measuring device (38) is positioned and oriented so as to generate at least one second raw data signal representing the distance to the tipping paper (27) of the cigarette (24).

11. The system of claim 10, wherein the controller and the signal processing unit (40) are configured to perform the method of claim 1.

12. The system according to claim 10, characterized in that the at least one first distance measuring device (36) and/or the at least one second distance measuring device (38) comprise one or more laser telemetry units.

13. The system according to claim 10, characterized in that the signal processing unit (40) is configured to filter the at least one first raw data signal and/or the at least one second raw data signal using a high frequency pass filter.

14. The system according to claim 13, characterized in that the signal processing unit (40) is configured to perform noise reduction on the high-pass filtered at least one first raw data signal and/or at least one second raw data signal.

15. The system according to claim 14, characterized in that the signal processing unit (40) is configured to perform the noise reduction using a median filter.

16. The system according to claim 10, wherein the signal processing unit (40) is configured to detect a seam signal within the raw data signal or the filtered raw data signal.

17. The system according to claim 16, wherein the signal processing unit (40) is configured to detect a seam signal by detecting a signal amplitude exceeding a threshold range to a statistically significant extent, the threshold range being selected or calculated such that random fluctuations of the filtered raw data signal remain within the threshold range.

18. A system according to claim 10, wherein the signal processing unit (40) is configured to detect the wrapping direction of the wrapper seam (26) and the tipping paper seam (28) by detecting a sign of an amplitude of the seam signal (62, 72).

19. A system according to claim 10, wherein the signal processing unit (40) is configured to detect an offset between the positions of the wrapper seam (26) and the tipping paper seam (28) on the circumference of the cigarette (24), the offset being indicative of a source track (TA, TB, FR-TA, FR-TB, RR-TA, RR-TB).

20. A cigarette inspection unit comprising a system for determining a source trajectory of products of the tobacco processing industry according to one of claims 10 to 19.