Abstract:
A method and system for food preparation and processing that determines the bulk density of food particulate matter input into particulate packaging machinery and performs bulk density feedback of packaged food particulate matter. The feedback mechanism inputs bulk density values into a controller that are referred against acceptable values. Where the input values of bulk density are outside the acceptable range the controller automatically alters the food preparation and packaging process to obtain acceptable bulk density values. The method system are applicable to any food manufacturing process, although they are particularly well suited to the manufacture of food in flake, chip, puffed or extruded form.

Description:
This application claims benefit of provisional patent application No. 60/345,972 filed Nov. 9, 2001. 

   FIELD OF THE INVENTION 
   The invention relates generally to food processing machinery and to electronic controllers for controlling such machinery. More particularly, it relates to machinery for producing flaked or particulate material such as breakfast cereals, cookies, baked goods, snack food, and the like that is divided into portions and packaged as individual portions of a predetermined weight and volume. In addition, it relates to machinery for volumetrically measuring individual package portions of such food products and weighing such portions. 
   BACKGROUND OF THE INVENTION 
   Many food products, such as those mentioned above, are individually packaged for sale on grocery store shelves. The packages have a finite volume typically on the order of 250 cubic inches and a finite weight, typically on the order of one-half to three pounds. For obvious reasons, manufacturers would like to maintain the weight of the product as closely as possible to the weight designated on the outside of the individual package or box. Underweight products violate federal packaging and marketing standards. At the same time, manufacturers cannot guarantee the minimum weight of food simply by providing an excess volume of food product. Boxes in which the food product is placed have a finite volume, and an excess volume may cause the boxes to distend outwardly, tearing them, or making it difficult or impossible to package them into cartons or containers for shipping. 
   Further complicating the processes of appropriately portioning the food product is the fact that the food product manufacturing process itself may cause the relationship between volume and weight to vary widely. The relationship between volume and weight is called the “bulk density”. Bulk density is expressed as units of weight per units of volume. Typically, it is expressed as ounces per cubic inch or grams per cubic centimeter, although these units of measure are not mandatory. If the bulk density of a food product increases dramatically as food processing equipment drifts from its nominal and preferred position, a unit of weight of the food product will take up a considerably smaller volume. While this is enough to meet federal and state packaging standards, since the weight is held constant, consumers are often upset because the large package they have only appears to be half full. Even though the weight is correct, the reduced volume leaves the consumer feeling angry and frustrated. Similarly, if the bulk density of the food product drops dramatically, a given weight of the product will take up a considerably larger volume. When this happens, if the portioning process for each of the packages is based solely upon weight, the portions will increase in volume and may jam the packaging machinery causing it to fail. This requires shutting down the packaging machinery and cleaning it out. Any shut-down of the food processing line imposes a significant cost on the food manufacturer. What is needed, therefore is a system and process for feeding back a signal indicative of the bulk density of the product being portioned and packaged to the food manufacturing process so that it can be adjusted on the fly and the proper bulk density, weight, and volume of each individually wrapped portion can be properly maintained. It is an object of this invention to provide such a system and process. 
   SUMMARY OF THE INVENTION 
   The invention can be summarized as a cup filler or other volumetric metering device that is configured to generate an electrical signal that indicates the bulk density of a volumetrically metered portion of particulate food matter. The cup filler is connected to food processing machinery that actually makes the particulate food matter and sends a signal indicative of the bulk density to the food processing machinery to which it is coupled. The food processing machinery includes an electronic controller that is configured to change at least one operational of the machinery itself in response to the received bulk density signal to thereby alter the bulk density of the food product. 

   
     DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which: 
       FIG. 1A  is a schematic illustration of a food preparation system in which raw materials are processed into continuous particulate matter, then portioned into individual portions of particulate matter, and then packaged; 
       FIG. 1B  shows an alternative embodiment of a food preparation system with a checkweigher; 
       FIG. 2  is a schematic diagram of the food processing shown in  FIGS. 1A and 1B  and of the electronic controller that communicates with the food processing machinery and regulates operational parameters of the food processing machinery based upon a bulk density signal received from the volumetric metering apparatus; 
       FIG. 3  illustrates the volumetric metering apparatus including a cup filler having a distance measuring device mounted on it for determining the relative position of the bottom plate with respect to the top plate to determine the volume of the cups, as well as an electronic controller that receives a signal from this distance measuring device; 
       FIG. 4  is a fragmentary cross-sectional view of an actuator used to raise a bottom plate of a cup filler with respect to a top plate, as well as the sensors and instrumentation for driving the actuator, and for weighing individual portions of food through use of either a weigh bucket or alternative embodiments of a checkweigher or centripetal force meter; 
       FIG. 5  is a close-up view of a cup and actuator of the cup filler of  FIG. 4 ; 
       FIG. 6  is a flow chart of the steps performed by the electronic controller of the volumetric metering apparatus to determine the bulk density of the particulate matter; 
       FIG. 7  illustrates the steps executed by the electronic controller of the volumetric metering apparatus in an embodiment of the system in which the electronic controller maintains the weight of each portion of particulate food matter constant by varying the volume; 
       FIG. 8  illustrates an alternative embodiment of the cup filler of  FIGS. 3-5  in which the actuator and motor of  FIG. 3  has been replaced with a rigid chain drive for raising and lowering the bottom plate with respect to the top plate; 
       FIGS. 9A and 9B  show a partial alternative embodiment of the cup filler in which the actuator of  FIG. 3  has been replaced with a cable cylinder that is fixed to the bottom plate to move the bottom plate with respect to the top plate; 
       FIGS. 10A and 10B  illustrate yet another alternative drive mechanism for raising the bottom plate with respect to the top plate of the cup filler, the drive mechanism comprised of an electric cylinder with a motor driven rod that is coupled to the bottom plate to raise it and lower it with respect to the top plate; 
       FIG. 11  is a flow chart of steps performed by electronic controller  200  when it changes operating parameters of any of the food processing machinery illustrated in response to the signal indicative of bulk density received from controller  312 ; and 
       FIG. 12  is a top view of the actuator  316  of  FIG. 3  taken at section line  12 — 12  in FIG.  3  and showing a chain and sprocket arrangement. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1A  illustrates the overall food processing system. On the left hand side, raw materials such as water, flour, grains, fruit, preservatives, humectants, sugar, vitamins, and the like, are input into the food processing machinery  100 . Food processing machinery  100  forms the raw materials into a continuous stream of particulate matter  102 . This particulate matter may be beads, pellets, flakes, or other small, discrete portions of food. The continuous stream of particulate food matter is combined, metered by volume and weighed in a volumetric metering and weighing apparatus  104 . The apparatus divides the continuous stream of particulate food matter  106  into individual portions of food that are to be packaged. The portioned particulate food matter  106  is then directed to the portion packaging apparatus  108 . In this apparatus, each of the portions that were provided to the apparatus  104  are individually wrapped, such as in waxed paper, plastic film, cardboard boxes or the like, and exit the system for distribution as shown by arrow  110 . In the volumetric metering apparatus  104  a signal  112  indicative of the bulk density of the continuous particulate matter is generated and transmitted to the food machinery  100 . 
     FIG. 1B  shows an alternative embodiment of the system illustrated in FIG.  1 A. Raw materials are input into food processing machinery  100 . Food processing machinery  100  processes raw materials into a continuous stream of particulate matter  102 . The continuous stream of particulate matter  102  is combined and metered by volume in the volumetric metering apparatus  114 . Alternatively, but not diagrammatically shown, apparatus  104  of  FIG. 1A  may be substituted for apparatus  114  of FIG.  1 B. The continuous stream of particulate food matter  102  is divided into individual portions of food that are to be packaged. The portioned particulate matter  106  is then directed to the portion packaging apparatus  108 . The portion packaging apparatus  108  individually wrap each of the individual portions of particulate matter. The individually wrapped products  116  continue through a checkweigher  118  and exit the process for distribution as shown by arrow  110 . A weight measurement signal  120  is generated by checkweigher  118  and sent to the volumetric metering apparatus  114 . Signal  112  is generated by apparatus  114 , and is indicative of the bulk density of the continuous particulate matter, and signal  112  is transmitted to the food processing apparatus  100 . Bulk density is calculated from known volume of particulate food matter and a weight measurement obtained from a weight sensing device, such as but not limited to a weigh bucket, centripetal force meter or checkweigher. This signal indicative of the bulk density  112  is used to control food processing machinery  100  such that the machinery generates a revised stream of continuous particulate matter that is closer to the target bulk density. 
     FIG. 2  illustrates one embodiment of the food processing machinery of FIG.  1 . In this embodiment, an electronic controller  200  receives the bulk density signal  112  and responsibly controls, based upon the magnitude of that signal, a variety of food processing devices. The electronic controller  200  is electrically coupled to these devices and receives sensor signals therefrom and calculates and applies actuator signals thereto. The devices include a enrober  202 , mixer/agitator  204 , a pre-conditioner  206 , a cooking extruder  208 , a batch steam cooker  210 , a forming and cooking extruder  212 , a pelletizing extruder  214 , a microwave oven  216 , a tempering oven  218 , flaking rolls  220 , shredding rolls  222 , deep-fat fryer  224 , gun-puffer  226 , toasting oven  228 , and baking oven  230 . Each of the devices  202 - 230  transmits sensor signals to controller  200  over communications lines  232 ,  234 , and  236 . Electronic controller  200  transmits control signals to drive the various actuators on these devices over communications lines  232 ,  234  and  236  as well. Each of the devices  202 - 230  may include an integral electronic controller to receive sensor signals and provide actuator signals to the mechanical and electrical components of that device. In this embodiment, communications lines  232 ,  234  and  236  are coupled to the electronic controllers in each of the devices  202 - 230  and communicate with the on-board electronic controller for that device. Electronic controller  200  may be a PLC or, preferably, an industrial PC. 
   Mixer/agitator  204  may be a paddle blender, a double ribbon blender, a paddle/ribbon blender, a plow blender/turbulent mixer, a fluidizing Forberg-type mixer, an air mixer, a V-blender, a cone mixer, a single blade mixer, or a speed flow continuous mixer. The mixer may be oriented vertically or horizontally. It preferably includes a variable speed motor coupled to the paddles or agitators, a control valve for regulating a flow of steam or hot water to the mixer  204  to regulate the flow of steam or water to the mixer in models so equipped. It also includes a temperature sensor that provides a temperature sense signal indicative of the raw material being mixed or agitated therein. The variable speed motor and control valves are controlled by signals provided either by the internal PLC or by electronic controller  200  over communication line  232 . The temperature sensor provides temperature signal to electronic controller  200  indicative of the temperature of the mix also over communication line  232 . The motor and control valve in mixer  204  may be driven directly by an on-board PLC or may receive their control signals from electronic controller  200 . 
   Preferred mixers include the automated mixers provided by AMF Bakery Systems, Air Process Systems &amp; Conveyors Company, Inc., and Dunbar Systems, Inc. Most preferred is the TBM Series Tilt Bowl Mixer manufactured by AMF that includes a PLC configured to control mixing speed, mixing and refrigeration time, and dough temperature. 
   Cooking extruder  208  and forming and cooking extruder  212  are preferably a twin screw extruder having a variable speed drive motor coupled to a splitter/reduction gear box to drive both screws. The motor is preferably a DC drive motor. The extruder preferably includes a pressure and temperature transducer fitted to the die block to monitor the temperature and pressure of the material being extruded. In addition, these extruders preferably include at least one electrical heating element (although steam may be used) that is connected to a variable power control to regulate the degree of heating. When steam is used, the extruder preferably includes an electronic control valve configured to throttle the steam provided to the extruder thereby permitting the temperature of the extruder and hence the material being extruded to be varied. In addition, a water-cooling jacket is preferably provided around the shell of the extruder to cool the extruder and hence the material when temperatures become too high. These extruders preferably include a dedicated controller, preferably a PLC that directly controls the motor drive and monitors the pressure transducer temperature transducer and controls the valve regulating steam flow rate and the power circuitry controlling the flow of electricity to the electrical heating elements. A preferred extruder  208  or  212  is the MPF Series Extruders manufactured by APV Baker, Inc. Another preferred extruder, in accordance with the foregoing description, includes the Wenger Magnum Series Twin Screw Extruder as configured with the Wenger Automatic Process Management System software operating in conjunction with the Wenger PLC. 
   The pelletizing extruder  214  is preferably a single screw extruder driven by a variable speed motor, preferably a DC or AC variable speed motor coupled to a gear reducer. The barrel of the extruder includes a water jacket disposed to conduct heat from the extruded material into circulating cold water. The extruder screw is preferable cored for water-cooling as well. An electronic control valve is coupled to the water jacket to provide electronic control of cooling flow rate through the water jacket. The temperature sensor is disposed on the barrel in at least one region, to sense the temperature of the barrel and provide feedback for the appropriate cooling. A die plate is fixed to the exit end of the extruder barrel and includes a plurality of passages through which the extruded material is forced. The extruder also includes an adjustable die face cutter having a multi-bladed knife disposed to rotate across the outer face of the die and cut off individual pellets as they pass through the passages in the die. This multi-bladed knife is coupled to a variable speed motor drive to control the rate at which individual pellets are cut off and thereby to control the size of the pellets that are produced. A preferred extruder in accordance with this description is the APV Baker Incorporated BPF-200 Series Extruder. The pelletizing extruder  214  preferably includes a PLC coupled to and configured to drive the variable speed motor that rotates the screw with respect to the barrel and the variable speed motor drive that rotates the multi-bladed knife with respect to the outwardly facing die face. 
   Microwave oven  216 , tempering oven  218 , toasting oven  228 , and baking oven  230  may be any of a variety of food processing ovens, such as infra-red ovens, convection ovens, fluidized bed ovens, microwave ovens, or ovens having a combination of these heating technologies inside. A preferred oven for use in toasting food products such as cereal flakes is the APV Baker Thermo Glide Toaster. This system includes an electronically controlled fan to vary the flow rate of hot air circulating around the particulate food as well as several temperature sensors responsive to the air temperature of the air within the oven and at least one variable speed motor for controlling the speed of the internal conveyor that conveys the particulate food matter through the oven. Ovens based on microwave technology include both a microwave generator and a microwave applicator. The microwave generator portion of the microwave oven preferably includes a PLC configured to continuously vary the power output over the entire range of 0% to 100%. A preferred microwave generator for use with the microwave oven is the Amana QMP-1759 Microwave Generator. A preferred microwave applicator is shown in U.S. Pat. No. 5,457,303, which is incorporated herein for all that it teaches. Alternative microwave applicators include any of the QMP-2103 Series Amana microwave continuous cooking systems. 
   Flaking rolls  220  are preferably of a dual-roll design having two pressure rollers with parallel axes that are closely aligned to each other to provide a small gap therebetween in which the pellets are crushed and turned into flakes. An example of such a flaking roll system can be found in U.S. Pat. No. 5,018,960. The system disclosed in the &#39;960 patent, which is incorporated herein for all that it teaches, is preferably modified to include a stepping or servo motor coupled to threadably adjustable devices  136  (shown in the &#39;960 patent) to rotate those devices and thereby change the nip clearance between the flaking rolls under electronic control such as by a belt or gear engagement. In addition, in a preferred embodiment these servo or stepping motors are preferably controlled by an on-board PLC in the block indicated by flaking rolls  220  in  FIG. 2 , thereby permitting flaking rolls  220  to communicate with electronic controller  200  over communications line  234 . In this manner, electronic controller  200  can control the nip clearance between the flaking rolls, either directly by being coupled to the motor driving the threadably adjustable devices  136  (as shown in the &#39;960 patent) or by transmitting signals to the PLC that is on-board flaking rolls  220  and directing that PLC to control the nip clearance between the flaking rolls. In addition, electric motor  130  in the flaking roll apparatus (as shown in the &#39;960 patent) preferably a variable speed DC or AC motor that is similarly connected via communication lines  234  to electronic controller  200  or to the on-board PLC which in turn controls motor  130  (as shown in the &#39;960 patent) and is responsive to motor speed commands transmitted by electronic controller  200  over communication lines  234 . In this manner, electronic controller  200 , either directly (by direct coupling to the drive motor  130  of the &#39;960 patent) or indirectly (by coupling to drive motor  130  (of the &#39;960 patent) through the on-board PLC of flaking rolls  220 ) is capable of varying the speed of the flaking rolls as well as varying their spacing. In an alternative embodiment of flaking rolls  220 , threadably adjustable devices  136  (as shown in the &#39;960 patent) are replaced with a hydraulic cylinder that can extend to increase the nip clearance or retract to reduce the nip clearance between the flaking rolls  76 ,  78  (of the &#39;960 patent). In a system such as this, the hydraulic cylinder is fluidly coupled to a hydraulic power unit (also included with flaking rolls  220 ) and the flow of fluid between the hydraulic power unit and the hydraulic cylinders is regulated by a bi-directional electro-hydraulic control valve disposed in hydraulic conduits coupling the hydraulic power unit to the flaking roll assembly such that by the application of electrical signals to the electro-hydraulic control valve it can increase the nip clearance between the rolls or decrease the nip clearance between the rolls, and can provide a predetermined load by regulating the hydraulic pressure in the cylinders which are directly proportional to the closing force holding the two rolls together. This electro-hydraulic control valve is preferably coupled indirectly to electronic controller  200  through the on-board PLC, which is coupled to and in communication with communication lines  234  and thereby with electronic controller  200 . 
   Shredding rolls  222  are formed in the conventional fashion as a plurality of rolls arranged in several roll stations, each station having two rolls, at least one of which having a plurality of circumferential grooves defined on an outer surface thereof, such that when the extruded food product is provided to the station or stations, comprising the shredding rolls or shredding mill, each station will subdivide or shred the material into a plurality of longitudinal threads of food product. Shredding rolls  222  preferably include a plurality of variable speed drive motors that drive the shredding rolls in each roll station or stand, and are coupled to the actual rolls to permit their speed to vary under electronic control. Similarly, each of the actual rolls is provided with internal passages through which cooling fluid (typically water) is conducted to cool the rolls during operation. An electrical proportional control valve is also provided as part of the shredding rolls  222  fluidly connected between the source of cooling water and the rolls themselves to regulate the flow of this cooling fluid through the rolls, thereby controlling the temperature of the rolls and the amount of cooling. In addition, shredding rolls  222  include at least one temperature sensor disposed to detect the temperature of the rolls and/or cooling water, and thereby permit the regulation of the temperature of the rolls by opening and closing the cooling fluid valve in response to the temperature. The motors, valve and sensors of the shredding rolls  222  are coupled over communication lines  234  to electronic controller  200 , thereby permitting electronic controller  200  to vary the speed of the rolls, vary the amount of cooling fluid passing through the rolls, and control the temperature of the rolls. 
   In an alternative embodiment, shredding rolls  222  include a PLC coupled to the motors, valve and temperature sensors. In this embodiment, the PLC is coupled to the electronic controller  200  and is configured to receive motor speed commands and cooling commands from electronic controller  200 . Examples of shredding rolls in accordance with the present invention are the shredding mills or rolls manufactured by Wolverine Corporation, such as the Wolverine 16 Station Shredding Line. 
   The food processing devices illustrated in  FIG. 2  produce a continuous stream of particulate food matter  102 , according to any of a variety of product recipes. Several of these recipes are disclosed in U.S. patents, for example U.S. Pat. No. 5,510,130; U.S. Pat. No. 5,709,902; U.S. Pat. No. 5,182,127; U.S. Pat. No. 4,844,937; and U.S. Pat. No. 5,919,503, all of which are incorporated herein by reference for all that they teach. 
   Depending on the particular food preparation process required, and as shown in the aforementioned patents and text, each of the devices  202 - 230  can be provided with raw material and can sequentially process the raw materials to produce the continuous particulate matter. The particular order in which the devices are used to process these raw materials are shown in the aforementioned patents. 
   Any of the actuators that have been described above and form a part of devices  202 - 230  will change the bulk density of the finished food matter, the continuous particulate food matter, and thus may be moved or otherwise varied, either in speed, position, length of time of operation, or temperature, to achieve a preferred bulk density to the particulate food matter produced by the food processing machinery. For example, changing the quantity of raw materials provided to the mixer/agitator will change the bulk density of the continuous particulate food matter. Changing the temperature at which any of the devices works by varying the heating or cooling applied to the devices will also vary the bulk density. Changing the speed at which any of the devices  202 - 230  operates will also alter the bulk density of the continuous particulate food matter. 
   Not all of the devices  202 - 230  are required for every possible process, however. For example, when producing breakfast cereal flakes, flaking rolls  220  would be used and shredding rolls  222  would not be used. Conversely, when manufacturing a shredded breakfast cereal, shredding rolls  222  would be used and flaking rolls  220  would not. Similarly, when making toasted flaked products, one of the ovens  216 ,  218 ,  228  or  230  would be used to toast the product and deep fat fryer  224  would not be used. When preparing puffed cereal products, gun puffer  226  would be used to puff the cereal and deep fat fryer  224  would not be used. 
     FIG. 3  illustrates a volumetric metering apparatus illustrated in  FIG. 1 , a volumetric filler shown here as a cup filler. The preferred embodiment of the cup filler is shown in the attached non-provisional patent application Ser. No. 10/062,966, entitled “APPARATUS FOR METERING AND PACKAGING BULK PARTICULATE OR FLAKED MATERIAL”, Jan. 31, 2002, which is incorporated herein for all that it teaches. In particular, the cup filler includes two buckets disposed underneath discharge chutes to weigh the measured volume of particulate food matter, in the present case the particulate food matter is placed in each bucket. As the cup plate  300  rotates, resting on the bottom plate  302 , it sequentially and alternately empties each filled cup  304  into a bucket. Each of the cups  304  provides the volumetric metering and portioning capacity of the system. Each cup  304  has a predetermined volume that is varied by raising or lowering the bottom plate  302  with respect to the top plate  306 . By altering the overlap of the two cylinders  308  and  310 , which comprise each one of the cups  304 , the volume of the each cup  304  is changed thereby changing the volume of dispensed particulate food matter. 
   Now referring to  FIG. 4 , an actuator  406 , as described in above referenced application Ser. No. 10/062,966, is configured to raise and lower the bottom plate  302  thereby varying the volume of the cups. As shown, actuator  406  is in the form of a first externally threaded cylinder  402  that is threadedly engaged to an internally threaded cylinder  404 . Internally threaded cylinder  404  is supported on locking ring  426 , which is pinned via pin  428  to output shaft  424 . A thrust bearing  430  is disposed between ring  426  and cylinder  404  to support the weight of cylinder  404  and to permit it to remain stationary while output shaft  424  rotates. Since cylinder  402  is threadedly engaged with cylinder  404 , it is also supported by cylinder  404  on bearing  430  and its weight is similarly transferred to ring  426  and through pin  428  to shaft  424 . A motor  400  is coupled to a drive pulley  420  to rotate drive pulley  420 . Pulley  420  is coupled to cylinder  404  by belt  422 , which extends completely around both drive pulley  420  and cylinder  404 . Thus, as pulley  420  is rotated by motor  400 , outer cylinder  404  rotates as well. When cylinder  404  rotates, it either raises or lowers cylinder  402  due to the threading action of their mutually engaged threads. Thus, bottom plate  302 , which rests on cylinder  402 , can be raised or lowered by the motor  400  whenever motor  400  operates. Referring to  FIG. 3 , when bottom plate  302  is raised and lowered, it raises and lowers the cup plate  300 . Cup plate  300  and top plate  306  rotate with respect to bottom plate  302  and move both first cylinder  308  and second cylinder  310  of each of the cups. When cup plate  300  is raised or lowered, the first cylinder  308  moves relative to the second cylinder  310 , which is stationary, of each cup  304 . As a result the cylinders move together and overlap more or pull apart and overlap less. When they move together, they serve to reduce the volume of each of cups  304 . When they pull apart and overlap less, they serve to increase the volume of each of cups  304 . In this manner, motor  400  functions to change the volume of the cups either by increasing or decreasing the volume. 
   While the embodiment shown in  FIG. 4  includes a belt that engages cylinder  404  to motor  400 , in an alternative embodiment a chain is preferred as shown in FIG.  12 . Referring now to  FIG. 12 , cylinder  404  can be replaced with an alternative cylinder  1200  having a plurality of gear teeth  1202  extending outwardly from its outer surface and collectibly defining a sprocket. In a similar fashion, the pulley  420  of  FIG. 4  can be replaced with a pulley  1204  having a plurality of outwardly extending teeth  1206  that collectably define a sprocket. About these two sprockets, a chain  1208  can be used instead of timing belt  422  shown in FIG.  4 . 
   Referring now to  FIG. 3 , controller  312  is shown as it is connected to an additional device in the system, a relative position-indicating device  314 . Device  314  is preferably a position sensor utilizing magneto restriction technology, such as the Temposonics RH series, fixed to bottom plate  302  and providing a signal indicative of the distance between bottom plate  302  and top plate  306 . However, other position sensing devices may be used, such as an ultrasonic range finding device. The device shown in  FIG. 4 , with the exception of device  314  and PLC  312 , is the cup filler illustrated in  FIGS. 1-4G  of non-provisional patent application Ser. No. 10/062,966 entitled “APPARATUS FOR METERING AND PACKAGING BULK PARTICULATE OR FLAKE MATERIAL”. 
   Device  314  determines the relative distance between plates  302  and  306  based upon the elapsed time between the launching of the electronic interrogation pulse and arrival of the strain pulse. It then provides a signal indicative of the distance between the two plates on signal line  316 , which is coupled to controller  312  and device  314 . In this manner, controller  312  is made aware of the relative spacing of plates  302  and  306 , and any changes in the spacing of the two cylinders  308  and  310  that comprise each of cups  304 . Position sensors appropriate for use as device  314  are manufactured by Temposonics, whereas ultrasonic range finders appropriate for substitution of device  314  are manufactured by Hyde Park. 
   Controller  312  is configured by an internal program to provide several signals on signal lines  324 . One or more of these signals are indicative of the bulk density of the product. As described above, the bulk density of the product is defined as the ratio of the weight of a predetermined quantity of the particulate matter, and the volume of that predetermined quantity.  FIG. 6  is a flow chart of the digital program executed by controller  312  in which it determines and transmits the signal or signals indicative of bulk density, as described more fully below. 
   At the bottom of  FIG. 4  is a schematic representation of a weigh bucket  318 . Each bucket is mounted on a load cell  320 , which includes one or more force measuring devices. These force-measuring devices communicate an electrical signal indicative of the weight of the bucket and its contents over electrical signal line  322 . In this manner, an electrical signal is produced, indicative of the weight of the bucket and its contents, for future processing. In a similar fashion, motor  400  is driven by an electrical signal provided on signal line  330 . Both lines  322  and  330  are electrically connected to electronic controller  312 , here shown as a programmable logic controller or PLC. Alternatively electronic controller  312  may be an industrial PC. Motor driver circuits  332  are provided to generate an electrical signal of sufficient magnitude to drive motor  400 . Signal conditioning circuit  326  is provided to condition electrical signals provided by load cell  320  to controller  312  over signal lines  322 . Controller  312  is configured to generate a plurality of signals that are provided to communication circuit  328 , which then applies them to signal lines  324 . The signals on signal lines  324  comprise the signal or signals indicative of bulk density that is/are provided to the food processing machinery in block  100 , and, more particularly, to electronic controller  200  in FIG.  2 . 
     FIG. 5  is a fractional cross sectional view of outlets  336 , top plate  306 , cups  304 , passages  500 , cup plate  300 , and bottom plate  302 . Outlets  336  extend downward from hopper  334  into top plate  306 , which is formed as a circular pan or tray. 
   The cups  304  are in the form of two cylinders. A first cylinder  310  is fixed to and extends below top plate  306 . Passage  500  defines the opening of first cylinder  310 . Cylinder  310  is preferably circular in cross section, and is fitted into second cylinder  308 . 
   The volume of cups  304  can be varied by raising and lowering bottom plate  302  with respect to top plate  306 . This raising and lowering is provided by actuator  406 , which is pinned to shaft  502 . Actuator  406  expands or retracts in length in response to an electrical signal generated by the electronic controller for this system. It is pinned to shaft  502  and supports bottom plate  302 , and cup plate  300 , including second cylinders  308 . When it expands in length, its top portion  504  raises with respect to shaft  502 . Since bottom plate  302  and cup plate  300  rest on actuator  406 , they are also raised. Cup plate  300  may be keyed to shaft  502  by key  506 . Key  506  slides upward in key slot  504  thereby keeping cup plate  300  rotationally coupled to shaft  502  in a plurality of vertical positions. When cup plate  300  is raised, cylinder  308  moves upwards around the outer surface of cylinder  310 . Since the two cylinders define the volume of each cup  304 , this upward motion causes a reduction in cup volume, and hence a reduction in the volume of bulk material metered into each cup. A similar increase in cup volume can be created by lowering the upper portion of actuator  406  thereby causing cylinder  308  to slide downward realtive to cylinder  310 . 
   In  FIG. 5 , outlet  336 , top plate  306 , passages  500 , cylinders  308  and  310 , cup plate  300  and bottom plate  302  are shown as forming one long continuous path through the system. This is not the orientation that they have in reality. If it were, cups  304  would provide no metering capability. As soon as outlet  336  was positioned over passage  500 , an unlimited quantity of bulk material would fall through the continuous passage formed by these elements until virtually the entire system was filled with bulk material. 
     FIG. 5  illustrates these elements as being vertically aligned simply for convenience of illustration. In fact, they are rotationally staggered in a specific fashion that permits cups  304  to be filled in one position and emptied in a second position. For this reason, when outlet  304  is oriented over the top of cup  304  and bottom plate  302  are not in the position shown in FIG.  5 . In fact, they are rotated to a different position in which the passage through bottom plate  302  is not below cup  304 . In this position bottom plate  302  provides a solid base to cup  304  thus permitting the cup to be filled. In a similar fashion, when the opening in bottom plate  302  is in the position shown in  FIG. 5  to permit the bulk material previously placed in cup  304  to fall into drop tube  508 , outlet  336  is not positioned above cup  304 . 
   In step  600  of  FIG. 6 , controller  312  receives data indicative of the volume of the cups  304 . In the preferred embodiment, device  314  generates a signal indicative of the relative spacing of top plate  306  and bottom plate  302 . This distance is related to volume by a linear relationship (given the right-cylindrical shape of cups  304 ) by the equation Y=MX+B, where X is the distance between the two plates, Y is the volume, M is a constant and B is a constant. Thus, there is a linear relationship between X and Y based upon the known inside diameters of the cups and the relative shapes of the cylinders comprising the cups  304 . 
   In an alternative embodiment for determining volume, controller  312 , which drives motor  400 , is programmed to maintain a counter in its electronic memory that is equivalent to the rotational position of motor  400 . Since the rotational position of motor  400  corresponds directly to the threaded engagement of the two cylinders,  402  and  404 , and since the threaded engagement of these cylinders also indicates the height of bottom plate  302  with respect to top plate  306 , the rotational position of motor  400  also indicates the volume of the cups by the relationship Y=MX+B, where X is the rotational position of motor  400 , Y is the volume of cups  304  and M is a constant and B is a constant. Thus, even when there is no separate device  314 , the volume of cups  304  can be determined by tracking the rotational position of motor  400  which drives bottom plate  302  up and down in a counter that is incremented or decremented when in a preferred embodiment, an initialization program is provided in controller  312  in which motor  400  is driven to a predetermined position and zeroed out. By “predetermined positions”, it is meant that the bottom plate would be moved until the cups have a known and predetermined volume and the motor counter in controller  312  would be set to a known value (such as zero) associated with this known volume. This “zeroing out” would then permit the volume to be determined based on relative motions of motor  400 . This process of initializing a counter based on the rotation of motor  400  could be automated by providing an electrical limit switch  432  that would be engaged by bottom plate  302  when it reached the predetermined position for zeroing out. Controller  312 , connected to the switch, will drive motor  400  until it sensed that the switch was engaged, thereby indicating that the cups  304  were in their position of predetermined volume. At which time, controller  312  will set the counter indicative of the motor&#39;s  400  rotational position to the predetermined value. 
   While the preferred embodiment permits the bottom plate  302  to be driven up or down with respect to the top plate  306  and thereby permits the volume of each of the cups  304  to be varied dynamically, this is not an essential requirement in determining the bulk density of the particulate food matter or of providing a signal or signals indicative of bulk density. Since bulk density is a ratio of volume to weight, if the cups have a fixed volume, the bulk density will vary only with the weight. 
   In step  602 , controller  312  receives data indicative of the weight of a portion of particulate food matter deposited in a weigh bucket  318 . In the preferred embodiment, load cell  320  includes circuitry  326  to generate a digital value indicative of weight. This data is transmitted over signal lines  322  to circuitry  326  in controller  312 . In this embodiment, device  320  is preferably a Tedea Model 910 Load Cell combined with a GSE 460 indicator. The Tedea Model 910 Load Cell provides an analog signal, and the GSE 460 indicator converts that analog signal to digital format. It is this data that is preferably provided over signal line  322  to controller  312 . Alternatively, the Tedea Model 910 load cell could be used as device  320  and the analog signal provided by the load cell on line  322  is sent directly to PLC  312 . In this embodiment, circuitry  326  would comprise an analog-to-digital converter. If controller  312  was an Allen-Bradley PLC, circuit  326  could be an analog-to-digital converter card manufactured by Hardy. Of course, any arrangement of strain gauges, load cells, or other deflection-measuring device that generates a signal indicative of the weight of the contents of the bucket could be used as device  320 . 
   In the preceding examples, the weight that was determined was the weight of a predetermined quantity of particulate food matter metered by a cup  304  into a fixed and stationary weigh bucket  318 . In an alternative embodiment, however, the weight of the predetermined quantity of material metered by each cup  304  as it directs particulate matter into drop tube  408  could be measured by a centripetal force meter instead of weigh bucket  318  and device  320 . Referring back to  FIG. 4 , in this alternative embodiment, as each cup  304  deposits the measured volume of particulate food matter into drop tube  408 , it would be directed into or against centripetal force meter  410 . Centripetal force meter  410  can be used in place of weigh bucket  318  and device  320 , and would be connected to controller  312  by signal line  412  and circuitry  434 . In addition checkweigher  118  is shown in  FIG. 4  as an alternative embodiment for determining the weight of the particulate food matter. The checkweigher  118  is downstream of the food packaging and would be connected to controller  312  by signal line  436  and circuitry  438 . 
   The checkweigher maybe used to replace or work in conjunction with either the weigh bucket or centripetal force meter weight sensor devices. In the alternative embodiment shown in  FIG. 1B , a checkweigher  118  located downstream of the packaging replaces the weigh bucket. The checkweigher measures the weight of the finished product. This value is compared to a reference value. Previously entered reference and deviation values are product specific. Volume information, combined with information relating to weight, from the checkweigher, is received by the PC/PLC. Information received by the PC/PLC is used to calculate bulk density, which in turn is used to thereby change upstream activities of the food processing machinery in order to obtain optimal product weight and bulk density. 
   In the alternative centripetal force meter embodiment, material is released from cups  304  and enters drop tubes or spouts  408 , it is directed downward against plate  414 , which is mechanically coupled to meter  410 . Plate  414  causes the particulate food matter to deflect in its direction of travel as shown by arrow  416 , which describes the path of the matter from drop tube  408  into feed tube  418 . As the matter is steered in a curved path, it deflects plate  414 , which in turn deflects measuring devices inside meter  410 . This deflection is amplified and turned into an analog or digital signal indicative of the force applied to plate  414  and is provided over signal line  412  to controller  312 . A preferred centripetal flow, meter for use in this system is the CFM Series centripetal force meter manufactured by CentriFlow. Of the meters in that series, the CentriFlow CFM-6 is especially preferred. The use of weight bucket  318  and centripetal flow meters  410  are two types of alternatives in place of a checkweigher  118 . These two alternatives, if so desired, may also be used with the addition of a checkweigher  118 . 
   The next step in the process of generating and transmitting the bulk density signal to controller  200  (i.e., food process  100 ) is that of determining the signal indicative of bulk density. As noted above, if cups having a fixed volume are employed in the cup filler (i.e., bottom plate  302  is not adjusted with respect to top plate  306 ) then the bulk density signal can be derived strictly from the weight data. The step of determining the signal indicative of bulk density is simply that of providing the signal indicative of the weight that is received from multiple types of devices  410 ,  320  or  118  as mentioned above. Each of these devices provides a signal indicative of the weight of a discreet volume or portion of particulate food product. Since the volume is fixed (in this example), the bulk density varies in direct relationship to the weight. Since bulk density is expressed as weight per unit volume, and since volume is fixed, the relationship is as follows:
 
 Y=MX  
 
where Y is the bulk density, X is the weight (derived from the signal provided by device  410 ,  320  or  118 ), and M is a constant of proportionality. An appropriate correction factor is provided in controller  200  to properly format the data for use in the food process control algorithms executed by controller  200 . It should be clear that the weight in itself, for a cup filler having a fixed volume cup  304 , is a signal indicative of bulk density  112 .
 
   In cup fillers such as the preferred embodiment shown herein where the volume can change as well as the weight, the signal indicative of bulk density  112  is a product of both the volume signal provided by sensor  314  and the weight signal provided by devices  410 ,  320  or  118 . Again, since bulk density is the ratio of weight to unit volume, controller  312  can directly calculate a value or signal indicative of bulk density by dividing the signal received from device  410 ,  320  or  118  by the signal received from sensor  314 . Expressing this in general form,
 
 Y=M ( W/V )+ B  
 
where Y is a value indicative of bulk density, M is a constant of proportionality, W is a value indicative of the weight signal received from devices  410 ,  320  or  118 , V is a value indicative of the volume signal received from device  314  and B is a second constant. Controller  312  is preferably configured to calculate Y and thereby provide a single value indicative of the bulk density of a measured portion of the particulate food matter. It should be clear that various additional scaling factors and offsets may be necessary in this and the other equations depending upon the resolution and signal format of devices  314 ,  410 ,  320  and  118 . In a preferred embodiment, controller  312  is configured to calculate this value Y by combining the weight signal and the volume signal and transmit this value over lines  324  to controller  200  as a signal indicative of bulk density  112 .
 
   In a preferred embodiment, controller  312  includes a control algorithm that is configured to maintain the weight of each portion of food constant. As I noted in the background of this invention, it is quite important with food products to meter a precise weight of food material into each individually wrapped package of food.  FIG. 7  illustrates this control process performed by controller  312  to maintain the weight of each portion constant. In  FIG. 7 , a target weight W t  is stored electrically in controller  312 . Controller  312  compares this target weight with the actual weight in summation block  700 . From this comparison an error signal (e) is generated. Controller  312  is programmed with a control algorithm indicated by block  702 , preferably a PID control algorithm, which uses this error signal to generate a motor drive signal (m). This motor drive signal is applied to motor  400 , causing the volume of cups  304  to change. By changing the volume of the cups  304 , the weight of subsequently measured volumes of particulate food matter by either of devices  410 ,  320 ,  118  is changed. This actual weight (“W a ”) is received by controller  312 , which feeds it back to the summation block  700  to begin the control loop all over again. While this is a preferred embodiment of a feedback control algorithm implemented in controller  312  and used to maintain the weight of each measured portion constant, other feedback control algorithms such as a PD or PI algorithm, for example, may be suitable depending upon the speed of response of the system. 
   Since varying the position of the motor  400  controls the weight, the rotational commands transmitted to the motor  400  to make it move to a predetermined position that will minimize the weight error can be combined with the existing motor position to determine the new position of the motor. For example, if motor  400  is a stepper motor or servomotor, the signal provided to motor  400  is typically going to be the amount of rotation expressed a number of revolutions through which the motor should be rotated to raise and lower bottom plate  302 . In either case, controller  312  can, as each correction to the motor position is received, sum these corrections to determine the current position of the motor  400  at any time. Since each motor position corresponds to a particular volume of each of cups  304 , the motor position is indicative of the cup volume. Furthermore, since the control algorithm shown in  FIG. 7  that is executed by controller  312  maintains the weight of each portion of particulate food matter constant, by minimizing the error signal “e”, the motor position is inversely related to the bulk density of the metered portion of particulate food matter that is being weighed. The equation that expresses this relationship is:
 
 Y=M (1/ M   p )+ B  
 
Where Y is bulk density, M is a constant, M p  is motor position and B is another constant.
 
   In other words, the greater the motor position measured as an angle or a series of pulses, the greater the volume of the cups. Since the weight is controlled by controller  312  to be constant, it is not a factor in this equation. Only the motor position signal, “M p ” determines the volume and hence the bulk density of the particulate food matter. Thus, when the weight is held constant by controller  312 , the motor position (or more generally the position of the bottom plate with respect to the top plate) is indicative of the bulk density of the particulate food matter. Y is preferably calculated by controller  312  and sent to controller  200  as a signal indicative of bulk density  112 . This step is represented by block  604  of FIG.  6 . 
   Stepper motors are inclined to slip. In other words, when motor drive signals are applied to stepper motors they occasionally do not rotate the desired or commanded amount. As a result, relying on the motor position as provided by the motor drive circuit or by maintaining a motor position counter that is the sum of all the motor position drive commands, may not provide an accurate indication of the motor position. In these cases, it is particularly beneficial to provide an independent motor position sensor such as a shaft encoder that is fixed to the motor to rotate with the motor. This shaft absolute encoder will provide a series of pulses with each increment of motor  400  rotation that can be counted and the rotational position of the motor (hence the volume of cups  304 ) can be determined. Alternatively, the motor can be driven in an open/loop fashion to maintain the weight constant and the signal from device  314  or any similar device that provides an indication of the position of the top plate  306  with respect to the bottom plate  302 , such as a Temposonics position sensor, can be used as a direct indication of the current volume of the cups  304 . 
   In step  606 , shown in  FIG. 6 , controller  312  transmits the signal or signals indicative of bulk density  112  to the food processing machinery  100  (i.e., controller  200 ). Since bulk density can be indicated either by weight data (when volume is held constant) or by volume (when weight is held constant) or by both volume and weight data (when both vary simultaneously) any one of these signals can be provided by controller  312  to controller  200  of the food processing machinery  100 . In the preferred embodiment, controller  312  provides all three values to controller  200  over communication lines  324 . These three signals include the weight data provided by devices  410 ,  320  or  118 , the volume data provided by device  314  (or volume data derived from the rotational commands sent to motor  400 , or from a shaft encoder configured to rotate with motor  400 ), and a combined volume and weight signal that is based upon the weight signal divided by the volume signal or reciprocal thereof. Of course, these values can be scaled or inverted, or additional correction factors combined with them in order to compensate for particular signal levels or formats provided by a position sensing device  314 , such as the Temposonics position sensor. In addition, controller  312  can provide discrete values, or it can provide moving averages of any of these foregoing values based upon the average bulk density of several successive weighed portions (re cupfuls) of particulate food matter based upon the weight and/or volume of a single portion (cupful) of metered particulate food material. 
   In the description of the cup filler including its controller  312 , particular components were described. Different components that provide the same capabilities may be substituted in the invention to provide the same capability, but with alternative structures. For example, rather than the threaded cylinder arrangement provided to drive bottom plate  302  up and down, a jack can be provided. This jack may be a hydraulic jack, a scissors jack, a pneumatic jack, or a motor driven ball-screw jack. In addition, motor  400  may be a servomotor, a stepper motor or a conventional DC or AC motor. Bottom plate  302  may be raised and lowered by a cable cylinder, such as that manufactured by Greenco or by a rigid chain driven by motor  400 , such as that manufactured by Serapid. Alternatively, a linear actuator, such as any of the actuators in the Rexroth Star would also be applicable.  FIG. 8  illustrates a rigid chain drive  800  driven by motor  400  through reduction gear box  802 . This would replace cylinders  402  and  404  (FIG.  4 ).  FIG. 9  illustrates a Greenco cable cylinder including a cable  702  fixed to bottom plate  302 . When the Greenco cable cylinder is driven, it moves cable  902  up and down with respect to top plate  306 . In  FIG. 9 , two views of the cup filler are shown, in  FIG. 9A , the bottom plate  302  is in a lowered position, and in  FIG. 9B  the bottom plate  302  is in a raised position 
     FIGS. 10A and 10B  illustrate yet another means of raising and lowering the bottom plate  302  with respect to top plate  306 . In this embodiment, rather than cylinders  402  and  404 , a linear actuator  1000  is provided that is fixed to a lower stationary portion  1002  of the cup filler and includes an extendable rod  1004  that is driven upward and downward with respect to housing  1006 . Motor  400  is coupled to a ball-screw or Acme threaded member (not shown) inside housing  1006  that engages with member  1004  to raise it and lower it with respect to stationary portion  1002 . The upper end of member  1004  is engaged with the bottom of bottom plate  302 , thus raising and lowering it with respect to top plate  306  whenever motor  400  is driven. Housing  1008  at the lower end of actuator  1000  covers either gears or belts that engage motor  400  to the servo ball-screw or Acme threaded member disposed inside housing  1006 . In this manner, rotation of motor, which is coupled to the ball screw,  400  causes member  1004  to raise and lower, thus raising and lowering bottom plate  302  with respect to top plate  306 . 
   The other components of the cup filler have been removed in  FIGS. 8-10  for better illustration of the different actuators that may be used in place of the cylinders  402  and  404 . Controller  312  and controller  200  are preferably programmable logic controllers or PLC&#39;s; such as the Automation Direct brand PLC, which is manufactured by Koyo, and preferably the D405 series, the D305 series, or the D205 series. Alternatively, an Allen-Bradley PLC from the SLC series or ControlLogix series, or MicroLogix series is also suitable. The Siemens 505 series or S-7 series PLC&#39;s are suitable, as is Modicon Quantum series PLC. Alternatively controller  312  and controller  200  may be industrial PC&#39;s. 
   The signals exchanged between controller  312  and controller  200  over communications lines  324  may be in the form of an analog voltage or current signal, or a digital signal following the RS232, RS422 or RS485 ASCII communications protocol. Alternatively, circuit  328  may be configured to communicate over lines  324  to controller  200  using the Allen-Bradley DF1 DH45 protocol, the DH Plus protocol, DeviceNet, Control net, RIO, or Ethernet. If a Automation Direct brand PLC is used, the preferred communications protocol is Direct Net, K-Sequence, Ethernet, Profibus, DeviceNet, or MODBUS. The signals indicative of the bulk density, (whether an expression of volume, weight, or a combination of volume and weight), are preferably not only digital signals, but are packetized in digital packets of predetermined lengths. Of course, other PLC&#39;s use other protocols that may be equally applicable to the system. 
   Controller  312  is configured to transmit the data in a first “direct” mode or a second “polled” mode of operation. In the direct mode of operation, controller  312  transmits one or all of the signals indicative of bulk density at predetermined time intervals, typically every ten (10) to fifty (50) milliseconds. In the direct mode, this is done without prompting by any other device connected to communication lines  324 . In the polled mode of operation, controller  312  is configured to receive a predetermined packet of digital information from controller  200  indicative of a request for bulk density data. In response to this, controller  312  is configured to packetize the latest signals indicative of bulk density and to transmit them to controller  200  over communication lines  324  including signals based on weight, on volume, and on combined weight and volume. The polled mode of operation reduces data congestion on communication lines  324 . Alternatively, controller  312  is configured to operate in a combined mode of operation in which the signals indicative of bulk density are transmitted at a predetermined interval yet controller  312  will also respond to queries for information from other devices on signal lines  324  (such as controller  200 ) by packetzing and transmitting specifically requested bulk density data as described above in the polled mode of operation. 
   Referring back to  FIG. 2 , electronic controller  200  is electrically connected to controller  312  as indicated by item  202  which shows the communications line over which electronic controller  200  receives the signal indicative of bulk density from electronic controller  312 . As described above, this data can be in analog form, although it is preferably in digital form and preferably packetized in discrete packets of fixed length. Electronic controller  200  is configured to control each food processing device  202 - 230  in accordance with the operating parameters identified in the patents and text identified above for producing ready-to-eat cereal. In the patents identified above, particular operating parameters, such as temperatures, pressures and speeds of processing for various ones of these devices  202 - 230  are described in greater detail. These operating parameters, and the methods of controlling them using PLC&#39;s or other electronic controllers are well known in the art. As identified above, many of them can be purchased, including their all-ready programmed PLC&#39;s from numerous product manufacturers. By changing any of the operational parameters controllable by machinery items  202 - 230 , the bulk density of the particulate food matter can be changed. For example, by changing the speed of agitation and mixing, or the temperature of the materials that are agitated and mixed, or the length of time the materials are agitated or mixed in device  204 , the bulk density of the particulate food matter will be varied. By changing the speed or temperature at which any of the extruders  208 ,  212 , or  214  operate, the bulk density of the particular food matter can also be varied. By changing the size of each pellet of food matter produced by pelletizing extruder  214  such as by speeding up the extruder screws, or speeding up the knife blade that slices off the pellets, or slowing it down, the bulk density of the particulate food matter can also be changed. Changing the roll spacing or force or temperature of either of flaking rolls  220  or shredding rolls  222  will similarly change the size and shape of the flaked or shredded material and therefore also change the bulk density of the particulate food matter. In a similar fashion, changing the temperature of operation of any of ovens  216 ,  218 ,  228  or  230 , or changing the speed at which material is conveyed through those ovens, such as by varying the power output by the microwave generator or the temperature inside the oven by varying the power to heating elements, will also change the way the particulate food matter or raw dough is treated and therefore also change the bulk density of the particulate food matter. Varying the rate at which coatings are emitted from the enrober  202  that are applied to each of the particles of the particulate food matter will change their weight and hence also change the bulk density of the particulate food matter so enrobed. 
   In short, changing any of the operational parameters of items  202 - 230  changes the bulk density of the particulate food matter. No specific bulk density, and hence no specific operational parameter is claimed in this application. Such a specific bulk density would only be applicable to a particular food item or desired texture or bulk density. Any specific recipe or set of processing parameters used to produce particulate food matter forms no part of this invention. 
     FIG. 11  is a block diagram of a portion of the programming performed by electronic controller  200 . The program represented by this block diagram is stored in an electronic memory inside electronic controller  200  and is executed periodically, preferably on an interval of between 10 and 100 milliseconds to alter the bulk density of the particulate food matter in response to the signal indicative of bulk density received from controller  312 . In step  1100 , electronic controller  200  receives density data, i.e., the signal or signals indicative of bulk density from controller  312 . This data can be received automatically, if controller  312  is operating in its direct mode. If controller  312  is operating in its pulled or combined modes of operation, controller  200  in step  1100  transmits a request for the signals indicative of bulk density, then receives those signals when controller  312  transmits them in response to the request. In step  1102 , controller  200  calculates the appropriate change in the operational parameters of the food processing devices  204 - 230 . Again, this calculation is performed by controller  200  based upon the numeric data received from controller  312  that is indicative of bulk density. An illustrative example of a parameter that can be changed is the size of the flakes produced by flaking rolls  220 . The size of the flakes is a function of the spacing of the flaking rolls, which in turn is varied by varying the force applied to the rolls or the spacing of the rolls. If the rolls are forced together more tightly for a predetermined size of pellet, they will increase the size of the flake and thus change the bulk density. If the size of the pellets is changed, such as by varying the speed of the extruder or the rotating knife that cuts off the pellets from the extruder, this change the volume of each pellet that is flaked and therefore when the pellet is inserted into the flaking rolls  220 , it will change the size of the flake, and thus change the bulk density. The appropriate change in the operational parameters of the food processing machinery is then initiated by the drive actuator  1104 . 
   While the embodiments illustrated in the FIGURES and described above are presently preferred, it should be understood that these embodiments are offered by way of example only. The invention is not intended to be limited to any particular embodiment, but is intended to extend to various modifications that nevertheless fall within the scope of the appended claims. 
   For example, some cup fillers vary the volumes of their cups not by moving a bottom plate up and down and holding a top plate stationary, but by moving the top plate up and down and holding the bottom plate stationary. In such a cup filler, rather than determining the distance between the top plate and the bottom plate by monitoring the changing position or motion of the bottom plate, one would instead monitor the changing position or motion of the top plate using a sensor such as device  314 .