Abstract:
A routing system for shared conduits used in industrial applications is sensitive to material types and material flow histories to allow compatible materials to flow through shared conduits without cleaning while preventing contamination of materials in those shared conduits.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0003]    The present invention relates generally to industrial control systems and, more particularly, to systems and methods for facilitating movement of materials. 
       BACKGROUND 
       [0004]    Integrated manufacturing operations involve high-complexity manufacturing processes. Such processes are involved in many areas of modern production. These areas include substantially any type of packaged products that are commonly found in grocery stores or other distribution outlets. For example, these products include beverages, flour, boxed items such as cereals, shampoo, liquid soaps, fertilizers, and so forth. Often, complex factory equipment arrangements and programming are provided to produce all or portions of such products. 
         [0005]    Production often involves the movement of materials through a series of production equipment. For example, in a beverage manufacturing operation, liquid materials including different types of beverages can be moved from a set of storage tanks to a filling station that can include multiple filling lines or bottling equipment for filling bottles, cans or other product packages. The beverages can be transported through a set of pipes connecting the storage tanks to the filling equipment. Typically, a shared network of interconnected pipes joined by valves is used so that each storage tank may communicate with each filling station, allowing great flexibility in pairing storage tanks and filling stations while avoiding the prohibitive cost of dedicated lines between each storage tank and each filling station. Header valves are arranged in an array providing a pass from each storage tank to one of a set of shared pipes. Similar valves join each of the filling stations to the shared pipes. By properly switching the sets of valves, material can be routed flexibly from any individual storage tank to any individual filling station. Further mixing operations can be conducted by routing multiple storage tanks to an individual filling station. 
         [0006]    A manufacturing operation can include hundreds of storage tanks, dozens of filling lines and multiple pipes connecting the storage tanks to the filling lines. Coordinating the flow of different beverage types by controlling both sets of valves can be complex. 
         [0007]    Movement of materials from multiple sources to multiple destinations through a limited set of intermediate containers is not limited to the context of beverage production or even to transport of liquid materials. Coordination of movement of gases and solids, for example granular materials (e.g., grains), create similar issues. 
         [0008]    A method of determining a route through an array of shared conduits is described in co-pending application Ser. No. 11/380,367, filed Apr. 26, 2006, and hereby incorporated by reference. The route may be used to control the electrically actuated valves to provide for an efficient transfer of materials. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention provides a routing system that is sensitive to the types of materials being routed and that can modify the routing for a shared conduit system to allow selected reuse of some conduits for different materials. The invention may distinguish not only between materials but also between orders of materials allowing two materials to pass in a first sequence in a conduit while blocking the same two materials from passing through the conduit in a different sequence. In this way, more efficient use of the shared conduits may be had without cleaning of the conduits while preventing contamination between materials. 
         [0010]    Specifically then, the present invention provides a computer-controlled material transport system for use for routing materials through a set of conduits joined by electrically controllable valves. The invention includes a routing system, designating a route through the conduit based on the need to transport a material from a source to a destination through the set of conduits, and a route controller. The route controller includes a valve controller receiving the route from the routing system and identifying valves to provide control signals to the electrically controllable valves to implement the route and a valve interlock locking implementation of the route based on a history of previous routes, indicating materials in the conduits, and based on a material compatibility array implementing rules about the mixing of materials. 
         [0011]    Thus it is an object of at least one embodiment of the invention to provide a sophisticated route management system that may better re-use shared conduits for more efficient transportation of materials. Because compatible materials may be identified, all mixtures of materials need not be prohibited while still preventing undesired contamination of materials. 
         [0012]    The valve interlock may receive a list of valves from the valve controller needed to implement the route and analyze the route based on the identified valves. 
         [0013]    It is thus an object of at least one embodiment of the invention to provide a simple method for evaluating conduit reuse driven by the identification of individual valves. 
         [0014]    The valves have an upstream and downstream side and the material compatibility array implements different rules for the same the materials depending on whether the materials are upstream or downstream. 
         [0015]    Thus it is another object of at least one embodiment of the invention to provide for sophisticated reuse in situations where the order of the materials may affect their compatibility. 
         [0016]    The materials include both product materials and cleaning materials the latter serving only to clean the conduits. 
         [0017]    It is thus another object of at least one embodiment of the invention to manage the routing in the context not only of materials to be routed but cleaning solutions used for cleaning shared conduits. 
         [0018]    The valve interlock may be implemented as a function block in a function block programming language for an industrial control system. 
         [0019]    It is thus another object of at least one embodiment of the invention to provide a sophisticated routing system that may be readily implemented in custom designed programs by control engineers. 
         [0020]    A clean pipe may be considered to be a material. 
         [0021]    It is thus an object of at least one embodiment of the invention to provide a system that recognizes clean pipes that are compatible with all materials. 
         [0022]    The route controller may provide a signal to the routing system when the implementation of a route is locked so that the routing system may designate a new, alternative route. 
         [0023]    It is thus another object of at least one embodiment of the invention to provide a system that can re-route materials to efficiently accommodate material compatibilities. 
         [0024]    These particular features and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a block diagram of a shared conduit system joining material sources (e.g. storage tanks) to material destinations (e.g. filling stations) as controlled by an industrial controller executing a program according to the present invention; 
           [0026]      FIG. 2  is a schematic representation of one shared conduit system showing multi-valve manifolds communicating between the shared conduit system and each of the material sources and material destinations; 
           [0027]      FIG. 3  is a detailed view of one manifold of  FIG. 2  as it communicates with a material source showing a designation of upstream and downstream connection lines; 
           [0028]      FIG. 4  is a figure similar to that of  FIG. 3  showing the manifold communicating with a material destination; 
           [0029]      FIG. 5  is a detailed block diagram of the program of the present invention showing a router that communicates a route to a route master module of the present invention, the latter which may communicate with a control module controlling various valves; 
           [0030]      FIG. 6  is a logical diagram of a material compatibility matrix used by the route master module of  FIG. 5 ; 
           [0031]      FIG. 7  is a logical diagram of a material history chart used by the route master module of  FIG. 5 ; and 
           [0032]      FIG. 8  is a functional block as may be used in a function block programming language incorporating the route master module of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0033]    Referring now to  FIG. 1 , a material transport system  10  may include material sources  12  communicating via primary conduits  14  with shared conduits  16 . The shared conduits  16  may communicate, via secondary conduits  18 , with material destinations  20 . Such a system may be found, for example in a brewery, where the material sources  12  represent holding tanks for different types of beer and the material destinations  20  are bottle filling machines. Nevertheless the present invention is not limited to this particular application. 
         [0034]    The shared conduits  16  may provide a number of pipes  22  passing in parallel between the material sources  12  and material destinations  20  as controlled by electrically actuated valves  24 . In this example, the valves  24 , control the passage of fluid in an on/off state; however, generally the term valve should be considered to embrace any control of passage of material between conduits. 
         [0035]    The valves  24  receive signals from I/O modules  26  of an industrial control system  30 , the latter which may communicate via a network  32  with a central programmable logic controller  34 . The programmable logic controller  34  may communicate via the same or a different network  36  with a programming terminal  38  or other programmable logic controllers or equipment (not shown). 
         [0036]    The programmable logic controller  34  incorporates a control program  40  typically prepared for a particular manufacturing operation and defining control of the valves  24  of the material transport system  10  as well as other components in the manufacturing process, for example the bottle filling machines  50  themselves. The present invention further provides a routing routine  42  that may work in context with the control program  40  to define routes through the shared conduits  16  based on the demands of the control program  40 . 
         [0037]    Typically the control program  40  will be written in a standard industrial control language to be readily modified according to the demands of the current manufacturing environment. Such standard industrial control languages include, for example, function block language, as will be described below, in which functional blocks are connected with virtual wires to provide for the programming of the system. 
         [0038]    Referring now to  FIG. 2 , in one topology, the shared conduits  16  may consist of a set of loops  43  formed of pipes  22 , shown for simplicity as concentric loops. Each material source  12 , for example, a tank  44 , may connect via a primary conduit  14  to a manifold  46  joining the primary conduits  14  to each of the pipes  22  of the individual loops  43 . The manifold  46  provides at each juncture, between primary conduits  14  and pipes  22 , a valve  48 . In this way, by selectively opening one valve  48 , a single path may be generated between, for example, tank  44  and the pipe  22  of one loop  43 . 
         [0039]    Conversely, each of the material destinations  20 , for example, a bottle filling machine  50 , may connect individually with pipes  22  of each of the loops  43  through a corresponding manifold  52  joined to the material destination  20  by secondary conduit  18 . Again the junctions between each pipe  22  and the secondary conduit  18  are controlled by electrically actuated valves  24  so that selection and activation of one electrically actuated valve  24  in manifold  52  creates a path between any pipe  22  and an individual bottle filling machine  50 . 
         [0040]    Referring now to  FIG. 3 , activation of a given valve, for example, electrically actuated valves  24   b , will join dedicated primary conduit  14  to loop pipe  22   b . For manifold  46 , the material in primary conduit  14  will be considered “upstream material” and material in pipe  22   b  will be considered “downstream material”. 
         [0041]    Referring now to  FIG. 4 , conversely for manifold  52 , a single valve, for example valve  24   d , may connect pipe  22   d  to secondary conduit  18 . In this case the material in pipe  22   d  will be considered to hold “upstream material” while the material in secondary conduit  18  will be considered to hold “downstream material”. 
         [0042]    Referring now to  FIG. 5 , the routing program  42  of the present invention includes a router  60  that, based on the need to move material from a material source  12  to material destinations  20  (as determined by the control program  40 ), determines one or more possible routes through the shared conduits  16 . The determination of this routing system may be done as described in co-pending U.S. application Ser. No. 11/380,367, filed Apr. 26, 2006 referenced above or by other means, including manual actions or pre-programmed template routes invoked by the control program  40 . 
         [0043]    This route information  62  is then passed to a route master program  64  of the present invention. At the route master program  64 , the route information  62  is provided to an equipment module  66  which determines the electrically actuated valves  24  which must be activated to implement the route of the route information  62 . These valves  24  are identified by reviewing the primary conduits  14 , secondary conduits  18 , and shared conduits  16  designated by the route information  62  and identifying as the valves  24  to be actuated those valves  24  providing the interfaces between the identified conduits, typically under the constraint that only one valve  24  of each manifold  46  or  52  will be actuated at a time. 
         [0044]    The identified valves  67  to be actuated are then provided to a route interlock program  68  of the present invention which determines whether those valves  24  to be actuated in fact may be actuated based on consideration of the particular materials that are upstream and downstream of each valve  24 . By reducing the problem of material compatibility to a simple analysis of upstream and downstream materials, complex and arbitrary compatibility rules may be effected. These rules are held in the compatibility matrix  70  read by the route interlock program  68 . The route interlock program  68  also reviews a flow history table  73  that provides ongoing information about upstream and downstream materials as will be described below. 
         [0045]    Referring now to  FIG. 6 , the material compatibility matrix  70  provides for a set of rows and columns each identified to a particular material in the universe of materials held in material source  12 . For example, these materials may include a “clean in place” material, such as a food safe detergent for cleaning the pipes as indicated by material ( 2 ), or particular product, such as a dark beer, as indicated by materials ( 3 ) through ( 6 ), or light beer, as indicated by materials ( 7 ) through ( 10 ). A virtual material ( 1 ) represents a clean pipe having no materials in it. 
         [0046]    The material compatibility matrix  70  distinguishes between upstream materials, which are identified to columns as depicted, and downstream materials identified to the rows as depicted. In order for a particular identified valve  24  determined by equipment module  66  to be opened, the intersection of the appropriate row and column of the material compatibility matrix  70  is reviewed to determine a compatibility of the proposed mixing. This compatibility is indicated in  FIG. 6  by the letter “Y”. So, for example, if the downstream product is a clean pipe shown by row ( 1 ), any upstream material may be introduced into that pipe as is indicated by a full matrix row of Y&#39;s. In another example, if the downstream material is a cleaning material ( 2 ), then only a clean pipe ( 1 ) may be an upstream material, and no other actual product, such as beer, can be introduced into this detergent. Note that the material compatibility matrix  70  distinguishes not only the material but also the order of introduction of the material. Thus, for example, a light beer represented by column ( 9 ) may not be introduced into a conduit earlier having had a dark beer, as represented by row ( 4 ) whereas a dark beer represented by column ( 4 ) may be introduced into a conduit earlier having had a light beer as represented by row ( 9 ). 
         [0047]    Referring again to  FIG. 5 , if the route is rejected by route interlock program  68 , a signal  77  may be returned to the router  60  so that an alternative route may possibly be determined. Similarly, this may occur if a signal  75  is returned from the control module  72  indicating a failure of valve  24  or the like. In this way, the natural redundancy of the shared conduits  16  may be fully exploited. 
         [0048]    Referring still to  FIG. 5 , only if the identified valves  67  provided by equipment module  66  are approved by route interlock program  68 , will the equipment module  66  provide those identified valves  67 ′ to the control module  72 . The control module  72  provides an outputting of control signals to cause actuation of the desired valves  24 . The router  60  and control module  72  operate together to allocate only pipes  22  that are not currently in use. 
         [0049]    Referring now to  FIG. 7 , the use of the compatibility matrix  70  by the route interlock program  68  requires an identification of upstream materials and downstream materials and thus an understanding of the historical path of materials through the shared pipes  22 . This is provided by the flow history table  73  which lists each valve and the upstream material (material A) and downstream material (material B). For example, as shown in row one corresponding to valve one, an upstream material may be material ( 3 ) and downstream material may be material ( 5 ). This table may also store the state of the particular valve  24  indicating whether it should be blocked from opening “Y” or interlock with respect to these two materials as determined from the material compatibility matrix  70 . For a manifold  46 , the flow history table  73  will initially show upstream materials corresponding to the material in the material sources  12  and downstream materials corresponding to a clean pipe. Conversely for manifold  52 , a flow history table  73  will initially show upstream materials corresponding to a clean pipe and downstream materials corresponding to a clean pipe. As materials are moved this flow history table  73  is updated. For example, when a valve is opened corresponding to row ( 4 ), the downstream material ( 2 ) will automatically be reset to be equal to upstream material ( 3 ). A flow history table  73  is provided for each manifold  46  and  52 . 
         [0050]    Referring now to  FIG. 8 , in a preferred embodiment, the routing program  42  of the present invention may be embodied in a function block  80  so as to be combined with other functional blocks of standard programming language to provide for this material sensitive routing capability. The function block  80  may receive route information  62  for receiving the route information from a router  60  (the latter implemented possibly as another functional block or as a set of custom programmed functional blocks) and return a status  82  indicating whether the route was in fact implemented. The values of compatibility matrix  70  and flow history table  73  may be provided by inputs  84  which provide for material names, material numbers and compatibility information (that is, each element of the compatibility matrix  70 ) for each combination of material A and material B. In this way, the information of the compatibility matrix  70  and flow history table  73  is invested into the function block  80 . 
         [0051]    The output of a function block  80  may be a list of the valve numbers  85  and their interlocked status sent to the control module  72 . Status data  75  may be reported back from the control module  72  to indicate the status of the valves  24  as being actually opened or closed to help update the flow history table  73 . 
         [0052]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.