Abstract:
The application relates to a method for tracking product data for a product mass flow in a transport storage section of the tobacco-processing industry having the steps: production of product data sets which each correspond to approximately equal portions of the product mass flow entering the transport storage section, writing the product data sets into corresponding memory units of a data memory and reading the product data sets corresponding to the product mass flow emerging from the transport storage section from the data memory. The application further relates to a corresponding product dating tracking system.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the priority of German Patent Application No. 10 2004 021 440.9 filed Apr. 28, 2004, the subject matter of which is incorporated herein by reference. The disclosure of all U.S. and foreign patents and patent applications mentioned below are also incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   The invention relates to a method and a system for tracking product data, for example quality data, brand information, production machine identification, production time, in a transport storage section of the tobacco-processing industry. 
   DE 102 16 069 A1 discloses a method and an apparatus for tracking product data for individual products in a machine in the tobacco-processing industry which operates with a certain machine cycle, i.e. processes a certain number of individual products per minute. The assignment of the product data to the individual products is based in this case on precise knowledge of the machine cycle and the length of path covered by the product in the machine. This method cannot be transferred to a product mass flow having numerous unordered individual products such as, for example, in a transport section between a cigarette production machine and a packing machine, since here the assignment of the product data to the individual products gets lost. This problem is aggravated when the length of path in the transport storage section is variable as is the case, for example, when a variable cigarette store is used. 
   SUMMARY OF THE INVENTION 
   The object of the invention consists in providing a method and a system for tracking product data for a product mass flow in a transport storage section in the tobacco-processing industry. 
   The invention solves this object in particular by the following steps and corresponding apparatus characteristics: production of product data sets which each correspond approximately to uniform successive portions of the product mass flow entering the transport storage section, writing the product data sets in corresponding memory units of a data memory and reading the product data sets corresponding to the product mass flow emerging from the transport storage section from the data memory. The invention is based in particular on the virtual apportioning of the product mass flow and the production and storage of product data sets corresponding to the individual portions of product. By means of this subdivision it is possible according to the invention to track product data averaged over a portion of product. 
   The data memory has a memory input and a memory output, wherein the product data sets are written via the memory input into the memory medium and are stored there in a fixed sequence and the product data sets written into the memory medium in a sequence matching the sequence of the corresponding portions of product in the transport storage section are read out from the memory medium via the output. 
   The transport storage section is a unit for the automatic transportation and/or storage of the product mass flow. Preferably the data memory maps the transport storage section logically. When, for example, the transport storage section comprises a pure transport section or a FIFO store in which the product mass flow enters at an entrance and exits in the same sequence at an exit the data memory usefully comprises a corresponding FIFO data memory (first in, first out principle). When, for example, the transport storage section comprises a cul-de-sac store into which the product mass flow enters and from which the product mass flow emerges in the reverse sequence the data memory usefully comprises a corresponding FILO or LIFO data memory (first in, last out or last in, first out principle). 
   A preferred implementation of a FIFO data memory is a ring memory having in each case a displaceable write and read pointer. Preferably, their position is shifted to a logically adjacent memory unit after a product data set has been written or after the emergence of a portion of product from the transport section. Furthermore, the position of the write or read pointer is preferably fixed in the event of a stoppage of the product mass flow entering the transport section or of the product mass flow leaving the transport section. 
   Another preferred implementation of a FIFO data memory is a FIFO stack memory (FIFO stack). Product data sets for a product mass flow entering the transport section are written to the FIFO stack memory and product data sets for the product mass flow emerging from the transport section are read out of the FIFO stack memory. 
   A preferred implementation of a FILO data memory is, accordingly, a FILO stack memory (FILO stack). 
   The invention is not restricted to said implementations of FIFO or FILO data memories. The use of shift registers, for example, is also covered by the invention. 
   The apportioning is preferably done in segments of uniform length of the product mass flow in the transport direction since this variable is particularly simple to determine from the speed of transport. Other types of apportioning are also conceivable, however, for example in portions having an approximately equal number of individual products or in portions of approximately equal weight. 
   Preferably the length or more generally the size of the product portions is adjustable in order to allow adaptation to different requirements. Preferably, the product data sets are set up for storing the length of the product portion in the transport direction. This can be useful in particular for transport storage sections having a plurality of transport segments of differing speed since in this case the length of the product portions varies. Preferably, the product data sets are set up for storing a product occupancy designation which specifies whether the transport segment corresponding to the product data set is occupied by product. This can be useful in order to identify a lack of occupation or other type of occupation of transport segments. 
   In order to identify a product mass stream entering the transport storage section or emerging therefrom the product data tracking system preferably comprises corresponding entry or exit sensors. 
   In the case of a majority of transport segments or transport devices in the transport section it can be useful to assign a data subset memory to each transport segment or each transport device. Each subset memory can, for example, be a ring memory having a write and read pointer, as described above. Each subset memory can also be constructed, by way of example, as a FIFO or FILO stack memory. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other advantageous characteristics emerge from the subsidiary claims and the following description of advantageous exemplified embodiments with reference to the attached drawings. These show: 
       FIG. 1 : a schematic overview of a product data tracking system for a transport section between a cigarette production machine and a packing machine; 
       FIG. 2  a schematic illustration of a product data set; 
       FIG. 3A : a schematic illustration of a cigarette mass flow being transported through the transport section at different times; 
       FIG. 3B : a schematic illustration of a ring memory as data store at the times shown in  FIG. 3A ; and 
       FIG. 3C : a schematic illustration of a FIFO stack memory as data store at the times shown in  FIG. 3A . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Cigarettes come out of a cigarette production machine  10  and are conveyed in the form of an unordered stream of cigarettes  11  containing, for example, of the order of 1,000 cigarettes per meter of transport section in the direction of the arrow by means of a transport section  12  to a packing machine  13 . The transport section  12  comprises a plurality of transport devices  14 - 17  which are drawn in the figures purely schematically as conveyor belts but by no means are restricted to these. The transport section  12  comprises inter alia a FIFO cigarette store  16  having a transport device  18  whose length is variable depending on storage demand as indicated in  FIG. 1  by means of dotted lines. 
   In the cigarette production machine  10  product data about the cigarettes produced are present, for example cigarette quality data, brand information, an identification of the production machine  10 , date and time of production, etc. The product data tracking system comprises a data processing unit  20  having a control means  21  and a storage means  22 . The control means  21  requests production data from the cigarette production machine  10  and periodically writes corresponding production data sets  30   a ,  30   b ,  30   c , . . . into the storage means  22 . By this means the product mass flow  11  is virtually subdivided into product portions  11   a ,  11   b ,  11   c , . . . as indicated in  FIG. 1  by dotted lines. When the transport speed of the stream of cigarettes  11  through the transport section  12  is, by way of example, 20 cm/s and the control means  21  writes production data requested from the cigarette production machine  10  once a second as production data sets  30   a ,  30   b ,  30   c , . . . into the storage means  22  this corresponds to a virtual apportioning of the product mass flow  12  into product portions  11   a ,  11   b ,  11   c , . . . of a certain length, in this example a portion length of 20 cm. In doing this, the production data set usefully contains production data averaged over one storage period. 
   An example of a format for a production data set  30  is shown in  FIG. 2 . A production data set  30  comprises by way of example a field  31  for storing the cigarette brand, a field  32  for storing the identity of the cigarette production machine  10 , a field  33  for storing the production date and time, a field  34  for storing the portion length (in cm in this case) and fields  35 ,  36 , . . . for storing cigarette quality data such as the average weight, the standard deviation of the average weight, etc. The label “1” in the product occupancy identification field  40  indicates that the data set  30  corresponds to a product portion and is not, for example, an empty portion as a result of an interruption of the product mass flow  11 . 
   Preferably, production data sets are written into the storage means  22  only when the product enters the transport section  12 . For this purpose, the entry sensor  23  is provided, which sends a corresponding signal to the control means  21  when a product enters the transport section  12  in order to activate the write operation, or in the event of an interruption of the product mass flow entering the transport section  12  to interrupt the write operation by means of a corresponding signal. 
   In a preferred embodiment the storage means  22  comprises at least one FIFO stack memory  26  in which the product data sets  30   a ,  30   b ,  30   c , . . . are stored in predetermined sequence in the form of a stack, wherein the product data sets  30   a ,  30   b ,  30   c  . . . first filed on the stack are read out again in the same sequence  30   a ,  30   b ,  30   c , . . . by taking them out of the stack (FIFO principle). 
   At the exit end of the transport section  12  an exit sensor  24  is preferably provided in order to detect product emerging from the transport section  12 . In the event of product emerging from the transport section  12  the control means  21  can, if required, read out the associated product data set from the storage means  22  and make it available for further use, for example transmit it to the packing machine  13 . This occurs when using a FIFO stack memory simply by periodic taking off of a product data set from the stack. Due to the fixed sequence within the stack and the FIFO principle it is ensured that the product data sets  30   a ,  30   b ,  30   c , . . . are correctly assigned to the product portions  11   a ,  11   b ,  11   c ,  11   d  . . . emerging from the transport section  12  regardless of the length of the transport section  12  in question, in the cigarette store  16  for example. The read-out period is usefully adapted to the exit period of the emerging product portions  11   a ,  11   b ,  11   c ,  11   d , . . . which is associated with the length of the emerging product portions  11   a ,  11   b ,  11   c ,  11   d , . . . . When the emerging product portions  11   a ,  11   b ,  11   c ,  11   d , . . . are of constant length and the transport speed over the entire transport section  12  does not change, the read-out period usefully matches the storage period. 
   It is not absolutely essential to provide a separate entry sensor  23 . The information about product entering the transport section can also be obtained, for example, from a component preceding the transport section  12 , in this case from the cigarette production machine  10 , if the information identifying a product portion is available there. The same applies to the exit sensor  24 , which can be dispensed with when the information identifying a product portion can be obtained, for example, from a component downstream of the transport section, the packing machine  13  in this case. This can be the case, for example, when instead of the length of the product portions in the transport direction the number of individual products per portion is used to define a product portion. 
   Even in the event of a stoppage of the product mass flow entering the transport section  12  it is not excluded to write product data sets to the storage means  22 . These then usefully contain a corresponding label, “0” for example, in a product occupancy identification field  40  in the product data set  30  (see  FIG. 2 ). 
     FIGS. 3A to 3C  serve to explain the storage and reading operation for a ring memory and a FIFO stack memory. In  FIG. 3A  the passage of a mass flow of cigarettes through the transport section  12  is shown schematically, wherein successive points in time are shown from top to bottom. The vertical line “E” designates entry into and the vertical line “A” exit from the transport section  12 . A product portion arranged over the line “E” is detected by the entry sensor  23  and a product portion arranged over the line “A” is detected by the exit sensor  24 . In  FIG. 3B  the corresponding memory state in each case of a ring memory  25  in the storage means  22  for storing the product data sets  30   a ,  30   b ,  30   c , . . . is illustrated. In  FIG. 3C  the corresponding memory state in each case of a FIFO stack memory  26  in the storage means  22  for storing the product data sets  30   a ,  30   b ,  30   c , . . . is alternatively shown. The memory units  25   a ,  25   b ,  25   c , . . . of the ring memory  25  or the memory units  26   a ,  26   b ,  26   c , . . . of the FIFO stack memory  26  serve for storing a product data set  30 . The ring memory  25  comprises a write pointer  27  and a read pointer  28 . The FIFO stack memory  26  comprises a stack input  50  and a stack output  51 . 
   The embodiment shown in  FIG. 3B  with a ring memory will be described first of all. At time t 1 , for example at start-up of the transport section  12 , the product mass flow  11  has not yet entered the transport section  12 . The write pointer  27  and the read pointer  28  are set to the same memory unit  25   a  of the ring memory  25 . At time t 2  product running into the transport section  12  is detected by the entry sensor  23 , a corresponding data set “1” is produced by the control means  21  and written to the memory unit  25   a  identified by the write pointer  27 . After this, the write pointer  27  is shifted by one memory unit while the read pointer  28  is kept in position since no product leaving the transport section  12  has been found. At time t 3  product running into the transport section  12  is detected by the entry sensor  23 , a corresponding data set “2” is generated by the control means  21  and written to the memory unit  25   b  identified by the write pointer  27 . After this, the write pointer  27  is again shifted by one memory unit. In analogous fashion at time t 4  the product data set corresponding to the product portion “3” is written to the memory unit  25   c  identified by the write pointer  27  and the write pointer  27  is again shifted by one memory unit. At time t 5  the entry sensor  23  detects that the product mass flow  11  entering the transport section  12  has been interrupted and therefore stops writing product data sets to the ring memory  25 . At time t 6  the exit sensor  24  detects that product is leaving the transport section  12 . Accordingly, it reads the product data set “1” to which the read pointer  28  refers from the ring memory  25  and which corresponds to the exiting product portion “1”. After this, the read pointer  28  is shifted by one memory unit. At time t 7  the product data set “4” is written to the memory unit  25   d  identified by the write pointer  27  and the write pointer  27  is shifted by one memory unit and also the product data set “2” is read out of the memory unit  25   b  identified by the read pointer  28  and the read pointer  28  is shifted by one memory unit. At time t 8  the product data set “3” is read out of the memory unit  25   c  identified by the read pointer  28  and the read pointer  28  is shifted by one memory unit. At time t 9  the exit sensor  24  detects that the product mass flow coming out of the transport section  12  has been interrupted and accordingly stops reading product data sets out of the ring memory  25 . At time t 10  the exit sensor  24  detects that product is coming out of the transport section  12 . Accordingly, the product data set “4” is read out of the memory unit  25   d  identified by the read pointer  28  and the read pointer  28  is shifted by one memory unit. At time t 11  the transport section  12  is empty and the ring memory  25  is in a state as at time t 1 . Since in this embodiment the write and read pointers  27 ,  28  are shifted along the memory units the memory is constructed as a ring memory  25  so that after a certain end memory unit the write and read pointers  27 ,  28  are shifted to a start memory unit (see time t 11 ). 
   In an embodiment having a FIFO stack memory  26  as shown in  FIG. 3C  the stack memory  26  at time t 1  is empty. The stack memory  26  has a stack input  50  and a stack output  51 . At time t 2  product running into the transport section  12  is detected by the entry sensor  23 , a corresponding data set “1” is generated by the control means  21  and placed on the stack, i.e. written by the stack input  50  to the stack memory  26 . At time t 3  product running into the transport section  12  is detected by the entry sensor  23 , a corresponding product data set “2” is generated by the control means  21  and written to the stack memory  26 . In analogous manner at time t 4  the product data set “3” corresponding to the product portion “3” is written to the stack memory  26 . At time t 5  the entry sensor  23  detects that the product mass flow  11  entering the transport section  12  has been interrupted and accordingly stops writing product data sets to the stack memory  26 . At time t 6  the exit sensor  24  detects that product is leaving the transport section  12 . Accordingly, it takes the product data set “1” from the stack, i.e. it reads out the product data set “1” from the stack output  51  of the stack memory  26 . At time t 7  the product data set “4” is written to the stack memory  26  and the product data set “2” is read out of the stack memory  26 . At time t 8  the product data set the product data set “3” is read out of the stack memory  26 . At time t 9  the exit sensor  24  detects that the product mass flow  11  coming out of the transport section  12  has been interrupted and accordingly stops reading product data sets out of the stack memory  26 . At time t 10  the exit sensor  24  detects that product is coming out of the transport section  12 . Accordingly, the product data set “4” is read out of the stack memory  26 . At time t 11  the transport section  12  is empty and, therefore, so is the stack memory  26 . 
   To each transport apparatus  14 - 17  in the transport section  12  a respective data subset memory can be assigned, in particular a ring memory  25  each with write and read pointers  27 ,  28  or a FIFO (or possibly a FILO) stack memory  26 . This allows handover of product data sets from one subset memory to a following subset memory on transfer of the corresponding product portions from one transport apparatus to the next transport apparatus. In particular on handover the product data sets can usefully be altered. This can be advantageous in particular when different conveying speeds occur in the transport section  12 . 
   In the example in  FIG. 1  it may be assumed that the conveyor  14  moves at 20 cm/s while the conveyor  15  moves at 25 cm/s and the product portions on entering the transport section  12  have a length L of 20 cm. After the transition of the product portions from the conveyor  14  onto the conveyor  15  they become longer and flatter due to the increase in speed; more precisely they have a length of 25 cm determined by the ratio of the transport speeds. If now, for example by means of a handover sensor between the conveyors  14  and  15 , it is detected that a certain product portion is coming out of the conveyor  14  the corresponding product data set is read out of the subset memory of the memory means  22  corresponding to the conveyor  14 , the length information in field  34  of the product data set is altered in accordance with the ratio of the transport speeds and the amended product data set is written to the subset memory of the following conveyor  15 . 
   It is not absolutely essential, however, in the case of a plurality of transport apparatuses  14 - 17  or when different transport speeds occur in the transport section  12  that to every transport apparatus or every transport segment a respective data subset memory is assigned. This can be dispensed with when, instead of the length of product portions, a variable which is independent of the transport speed is used for determining the product portions, for example the number of individual products per product portion. A single data memory for the entire transport storage section can then be sufficient. 
   The invention has been described in detail with respect to exemplary embodiments, and it will now be apparent from the foregoing to those skilled in the art, that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the appended claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention.