Patent Application
20130060376
The present invention relates to a computerized control device and a computer-implemented method for regulating the speed of a conveyor in a printed product processing facility. The present invention relates in particular to a computerized control device and a computer-implemented method for regulating the speed of a conveyor for delivering printed products to stacking devices which form stacks from supplied printed products.
In printed product processing facilities, products are formed in collecting facilities from a plurality of intermediate and primary products by collation, insertion or collection (in the narrower sense), with these products being supplied by a conveyor to one or more stacking devices which stack the products to form stacks. In the known printed product processing facilities, the speed of the conveyor is matched fixedly to the processing speed or the processing power of the stacking stations used. In the event of failure of a stacking device, the conveying speed needs to be reduced to a defined value corresponding to the remaining available stacking stations. In this case, it is often necessary to stop the printed product processing facility and/or to resume operation at a manually set, reduced conveying speed. In order to prevent overload of the stacking devices and reduce failures as far as possible, the conveying speed is limited fixedly to a value which is below the maximum possible processing power of the stacking devices, in particular when the stacking devices are intended to produce stacks with different and sometimes varying sizes.
The laid-open specification EP 1 935 821 describes a method for stacking printed products in a production line, in which the process for collating the printed sheets to form intermediate products is controlled depending on the stack size to be formed. According to EP 1 935 821, a minimum number of cycles which are required by the stacking devices for forming a stack is calculated on the basis of the cycle time for the delivery of a stack and the cycle number at which the production line produces. If particularly small stacks need to be formed with a relatively low number of cycles, empty cycles are introduced in the production line according to EP 1 935 821, which reduces the production capacity of the production line.
An object of the present invention is to propose a computerized control device and a computer-implemented method for speed regulation during delivery of printed products to stacking devices which do not have at least some of the disadvantages of the known systems. It is in particular an object of the present invention to propose a computerized control device and a computer-implemented method for regulating the speed of a conveyor for delivering printed products to stacking devices which enable flexible production of stacks of different sizes.
In accordance with the present invention, these aims are achieved in particular by the elements of the independent claims. Further advantageous embodiments emerge also from the dependent claims and the description.
The abovementioned aims are achieved by the present invention in particular in that, in order to regulate the speed of a conveyor for delivering printed products to stacking devices which form stacks from products supplied, an assignment plan is run for the stacking devices with products which were detected at a detection point upstream of the stacking devices on the conveyor and are processable by in each case one associated stacking device at a defined setpoint speed of the conveyor. The setpoint speed of the conveyor is automatically reduced when it is not possible to determine, in the assignment plan for at least one product, a stacking device which can process the at least one product at the unreduced setpoint speed of the conveyor, i.e. when the product in question in the assignment plan cannot be associated to one of the stacking devices in such a way that it is processable at the unreduced setpoint speed of the conveyor. In this case, it is determined, for a product, preferably on the basis of the present position of the product in question, on the basis of the processing speeds of the stacking devices, on the basis of the setpoint speed of the conveyor, and on the basis of the association of products to in each case one of the stacking devices according to the assignment plan, whether and by means of which of the stacking devices the product in question is processable at the defined setpoint speed of the conveyor. In this case, the present position of a product on the conveyor defines in each case its relative position or distance with respect to the inputs of the stacking devices.
Preferably, in each case one present position on the conveyor or in the associated stacking devices is determined for the products included in the assignment plan, and the setpoint speed of the conveyor is increased when a product which has been the cause of a reduction in the setpoint speed of the conveyor has reached a defined position (in the printed product processing facility). The setpoint speed of the conveyor is increased, for example, when the product which has been the cause of a reduction in the setpoint speed of the conveyor has reached the release point for transfer to the associated stacking device or has already been triggered at this point and has been transferred to the stacking device or has been processed prior to the stacking device.
The determination as to whether and by means of which of the stacking devices the products transported on the conveyor are processable at the defined setpoint speed of the conveyor and the virtual assignment of the products to the individual stacking devices based thereon enable automatic, dynamic and flexible matching of the conveying speed to product-specific parameters and states, such as product thickness, stack size, number of products in stack, stack structure and availability and processing speed of stacking devices, wherein an overflow of non-processable products is avoided as far as possible and the production capacity (i.e. products/time) is kept as high as possible. In particular in the case of a plurality of stacking devices, this dynamic matching of the conveying speed enables a high degree of flexibility in the stack formation with individually different and temporally varying stack sizes in the individual stacking devices.
In a preferred variant embodiment, the present conveying speed of the conveyor is set to the setpoint speed in each case at a defined point in time and, in the assignment plan, a product is associated to one of the stacking devices when the product in question is processable by the stacking device in question at a conveying speed which is set to the reduced setpoint speed from the defined point in time on.
In one variant embodiment, the time for setting the present conveying speed of the conveyor to the reduced setpoint speed is set to be as late as possible such that the product in question is still processable by the associated stacking device in question. Prolonging a reduction in speed as long as possible has the advantage that the conveying speed and therefore the operating performance are kept as high as possible, while the processability of the product is maintained and a product overflow is avoided.
In one variant embodiment, the present conveying speed of the conveyor is set to the setpoint speed at periodic points in time. The period of the points in time for the gradual matching of the conveying speed to a reduced or increased setpoint speed is preferably a multiple of the time period in which two successive products on the conveyor pass a fixed reference point, for example the detection point. At a conveying speed of 36 000 products/h, the period between two products is 0.1 second, for example, and the gradual matching of the conveying speed is performed, for example, in each case after ten products in a single-second cycle. The limitation of the matching of the conveying speed to points in time which follow one another in identical time segments has the advantage that an excessively frequent change in the conveying speed and an inclination of the system to oscillate, which is associated therewith, are avoided. In a combined variant, the above-described point in time which is as late as possible is fixed to the directly preceding “periodic point in time”.
In a further preferred embodiment, in the event of a reduction in the setpoint speed of the conveyor, the products which are included in the assignment plan and are still located on the conveyor are each associated afresh to one of the stacking devices which can process the product in question at the reduced setpoint speed of the conveyor. The fresh assignment of the products which have not yet been triggered and which are not located in the overflow region in the event of any reduction in speed enables continuous automatic optimization of the production planning and implementation by processable assignment of the products to the stacking devices in a manner matched dynamically to the conveying speed.
In addition to a computerized control device and a computer-implemented method for regulating the speed of a conveyor for delivering printed products to stacking devices, the present invention moreover relates to a computer program product which comprises a computer-readable storage medium with a stored computer code. The computer code is configured to control one or more processors of the control device in such a way that the processors or the control device run an assignment plan for the stacking devices with products which were detected at a detection point upstream of the stacking devices on the conveyor and are processable by in each case one associated stacking device at a defined setpoint speed of the conveyor, and that the processors or the control device reduce the setpoint speed of the conveyor when at least one product in the assignment plan cannot be associated to one of the stacking devices in such a way that it is processable at the unreduced setpoint speed of the conveyor.
An embodiment of the present invention will be described below with reference to an example. The example of the embodiment is illustrated by the following figures attached:
Approaches for implementing the invention
In
The printed product processing facility 1 and in particular the conveyor 2 operate in a so-called off-line mode, in the sense that they are not coupled directly to machines for producing printed products, but receive the printed products from a product store.
In the configuration shown in
In one variant embodiment, one or more product processing devices, for example a stretch wrapping machine for packing the products P in a packaging wrap, are arranged between the collecting facility 4 and the conveyor 2. Further product processing devices 21, 22 are also arranged in the case of the conveyor 2, depending on the variant embodiment, for example a stapler for stapling the product during transport with a product carrier 20, or an addressing device for printing or sticking an address of a recipient, an information sheet, a trade sample or another add on to the products P held in a product carrier 20.
As can be seen from
The reference symbols 2A, 2B, 2C in
In
As is illustrated in
The control device 5 comprises one or more operational computers each having one or more processors. The control device 5 is preferably connected to the various components of the printed product processing facility 1, in particular to the conveyor 2, the product detector 23, the release devices 2A, 2B, 2C, 2U, the stacking devices A, B, C, the overflow station U, the product processing devices 21, 22, the collecting facility 4, the separating devices 31, 32 and to various sensors, actuators and counters of these components, via the communications link 6 for data interchange.
As is illustrated schematically in
The control module 54 is configured to control the printed product processing facility 1 on the basis of the route plan 56 in such a way that stacks for delivery which comprise a plurality of products P consisting of a primary product HP and one or more intermediate products VP and are produced and arranged in such a way that they can be transported and delivered in accordance with the route plan 56, are provided in the stacking devices A, B, C.
The route plan 56 comprises route information or address information for the delivery of stacks comprising a plurality of products P with an association of stacks to defined delivery sequences or geographical positions, for example an association of stacks with products P assembled according to a specific product structure to specific routes, addresses or zones. Individual products P can be assembled and/or addressed individually for a recipient in one variant embodiment.
The tracking module 51 is configured to track the products P conveyed on the conveyor 2 in respect of their contents, i.e. primary products HP and intermediate products VP, and their positions on the conveyor 2, for example relative to the detection point DD and/or relative to one or more of the release points AA, BB, CC, UU (tracking information). In order to produce individualized products P which are provided, for example, with an individual address of a recipient and/or, in terms of content, with content which is geared individually to the recipient in question, a product P can be identified over its entire delivery time on the conveyor 2, from the collecting facility 4 up to stacking in a specific stack in one of the stacking devices A, B or C, or screening in the overflow station U, and tracked in terms of its position.
The planning module 53 is configured to associate the products P detected by the product detector 23 at the detection point DD in each case in the assignment plan Z dynamically to one of the stacking devices A, B, C, as is described in the following sections in respect of
The regulation module 52 is configured to match the conveying speed of the conveyor 2 dynamically and automatically to the capacity utilization, processing capacity and availability of the stacking devices A, B, C, as is likewise described in the sections below in respect of
In step S1, the product detector 23 detects a product P* conveyed past the detection point DD on the conveyor 2. The corresponding detection signal is passed via the communications link 6 to the control device 5, where the detection of the product P* activates the tracking module 51 for tracking and associating the product P* to the superordinate route plan 56, and the planning module 53 for associating the product P* to one of the stacking devices A, B, C.
In
In the schematic illustration of the assignment plan Z in
The reference symbols ZA, ZB and ZC in
At point in time T1, a stack P5, P20 with five or twenty products P, respectively, is completely formed in the stacking device A, B, C.
At point in time T2, for example 0.5 second after point in time T1, a layer L5 with five products P was formed on the intermediate stacker 7, while the stack P5 or P20 formed has been conveyed out of the stacking device A, B, C through a distance s.
At point in time T3, for example 1.0 second after the point in time T1, the intermediate stacker, and therefore the stacking device A, B, C in question, is prevented from receiving further products P in the upper example in
At point in time T4, for example 1.5 seconds after point in time T1, the stack P5 or P20 was conveyed out of the stacking device A, B, C through the further distance s both in the upper example and in the lower example in
At point in time T5, for example 2.0 seconds after point in time T1, the stack P5 or P20 was conveyed completely out of the stacking device A, B, C both in the upper example and in the lower example in
As is illustrated in the example in
In
B, C because a product P in question on the conveyor 2 cannot be assigned to the stacking device A, B, C owing to a superordinate route plan 56 or because the stacking device A, B, C has a technical problem and is not available, at least temporarily.
As shown in
In step S3, the planning module 53 checks whether the detected product P* could be assigned for processing to a stacking device A, B, C or whether it needed to be associated to the overflow region dU. In the case of an assignment for processing to a stacking device A, B, C, the regulation module 52 moves onto step S4, otherwise to step S5.
In step S5, the regulation module 52, on the basis of the detected product P* which could not be associated as processable to a stacking device A, B, C, initiates a reduction in the conveying speed vF of the conveyor 2 by virtue of the fact that it fixes a setpoint speed 55 vset which corresponds to the conveying speed vF reduced by a defined difference value Δv for example vset=vF−Δv=36 000 products/h−1000 products/h=35 000 products/h.
In step S6, the planning module 53 performs, on the basis of the setpoint speed 55 vset, a reassignment of the products P which have not yet been released and are located on the conveyor 2 in sections dA, dB or dC. In this case, depending on the variant embodiment or selected operating mode, various reduction points in time are assumed at which the actual present conveying speed vF is set to the setpoint speed 55 vset.
In a first variant, the reduction point in time is fixed to a fixed time period, i.e. a gradual reduction in speed takes place possibly at periodic points in time, for example in each case after one or after ten seconds.
In a second variant, the reduction point in time is fixed to a point in time at which a fixedly determined point on a section between the detection point DD and the release points AA, BB, CC is reached, for example the point in time at which the most recently detected product P* reaches a predetermined distance from one of the release points AA, BB, CC.
In a further variant, the reduction point in time is fixed at a point in time which is as late as possible (for example at one of the periodic points in time) in such a way that a processable assignment to stacking device A, B, C results for all products which have not yet been released. This latest possible point in time is determined iteratively, for example, with various points in time being checked at which a specific point on a section between the detection point DD and the release points AA, BB, CC is reached (for example by the most recently detected product P*), for example in accordance with fixed distances (for example at 90%, 80%, 70% etc.) or stepwise as in the case of a binary search algorithm.
In the case of the reassignment of as yet unreleased product P, a varying conveying speed vF is therefore assumed which corresponds to the present conveying speed vF up to the reduction point in time and, from the reduction point in time on, is reduced to the setpoint speed 55 vset. The reassignment preferably takes place beginning with the “oldest” as yet unreleased product P, which is located at the next to last release point CC, then the “younger” products P up to the “youngest” product which is the most recently detected product P*, in accordance with the criteria which were already described in connection with step S2.
In step S7, which is optional, the planning module 53 checks whether all of the as yet unreleased products P could be assigned as processable to one of the stacking devices, A, B, C at the setpoint speed 55 vset. If this is not the case, in step S5 a further speed reduction is optionally determined and/or in step S6 an earlier point in time for the speed reduction is checked iteratively.
In step S4, the planning module 53 checks whether a product P which has been the cause of a reduction in the conveying speed vF or setpoint speed 55 vset of the conveyor 2 has reached a defined position, for example the release point AA, BB, CC of the associated stacking device A, B, C and increases the setpoint speed 55 vset of the conveyor 2 by the defined difference value Δv.
In step S8, the regulation module 52 checks whether the point in time for a gradual matching of the conveying speed vF has been reached, i.e. whether the present time value corresponds to the point in time fixed for a speed matching or a specific product P has reached a correspondingly defined position on the conveyor 2. If this is the case, the regulation module 52, in step S9, sets the conveying speed of the conveyor 2 to the setpoint speed 55 vset, i.e. the present conveying speed is reduced or increased by a defined difference value Δv.
In
Finally, it should be mentioned that although computer program code has been associated to specific functional modules in the description and that the implementation of steps in specific sequences has been represented, it will be clear to a person skilled in the art that the computer program code can be structured differently and the sequence of at least certain steps can be changed without in the process deviating from the protected subject matter.
| Number | Date | Country | Kind |
|---|---|---|---|
| 00340/10 | Mar 2010 | CH | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/CH11/00031 | 2/22/2011 | WO | 00 | 11/13/2012 |
