Method and device for controlling a papermaking machine

Abstract: The invention relates to a method for controlling a papermaking machine/board machine/tissue machine or such, which papermaking machine/board machine/tissue machine or such includes basic unit assembly groups, such as a head-box, a wire section, a press, a drying section, a coating unit, a finishing machine, etc. The machine control system of the papermaking machine/board machine/tissue machine or such comprises a central processing unit (e.g. a unit for control room, alarm and other such functions), one or more process control units, and one or more input/output units, which are connected by control cables to the controlled units or actuators. In the method the process control units and/or input/output units of the machine control system are located in a mechanical machine part in connection with basic unit assembly groups of the papermaking machine/board machine/tissue machine or such. The invention also relates to an integrated machine control module in the machine control system of a papermaking machine/board machine/tissue machine or such. The integrated machine control module comprises an internal cabinet, wherein the process control units and/or the input/output units of the machine control system are located. Said internal cabinet equipment is arranged for monitoring ambient conditions as well as equipment for removing stresses caused by ambient conditions in such a way that the integrated machine control module can be located in ambient conditions existing in connection with basic unit assembly groups of the papermaking machine.

Description: The invention concerns a method for controlling a papermaking machine/board machine/tissue machine or such, which papermaking machine/board machine/tissue machine or such includes basic unit assembly groups, such as a headbox, a wire section, a press, a drying section, a coating unit, a finishing machine etc., and wherein the machine control system of the papermaking machine/board machine/tissue machine includes a central processing unit (e.g. a unit for control room, alarm and other such functions), one or more process control units and one or more input/output units connected over control cables with the controlled units or actuators. The invention also concerns a machine control system including an integrated machine control module for machine control system of the papermaking machine/board machine/tissue machine or such, which machine control system includes a central processing unit (e.g. a unit for control room, alarm and other such functions), one or more process control units and one or more input/output units as well as data transmission connections between the said units. The present invention is concerned with a papermaking machine's machine control system and with the location of its components. In this context, a machine control system means machine control, process control, quality control and monitoring systems. The method according to the invention is also suitable for use in machines for reconverting paper/board (printing machines, laminate production). The machine control system for use in controlling a papermaking machine includes process control units and input/output units, which in known solutions are given centralised locations outside the machine components. From the location compartment cables are drawn to the papermaking machine's basic unit assembly groups and the cables are connected with each controlled piece of equipment or machine part. In such an arrangement the process control units and input/output units of the machine control system are located in a compartment intended for electric equipment, wherein they are protected against moisture, temperature variations and other environmental stresses. In the arrangement described above, a control cable is brought to each controlled unit of the papermaking machine from an assembly compartment, which is located elsewhere and wherein the machine control system's process control units and input/output units are located. This cabling work between the assembly compartment and the basic unit assembly groups is done on the work site where the papermaking machine is installed. The installation work includes drawing of main cables and unit cables, connecting of cable ends and testing of cable connections. The above-mentioned connecting work is done after the mechanical machine installation and it prolongs considerably the time needed for installation of the papermaking machine. Locating equipment units of the machine control system in connection with the papermaking machine's basic unit assembly groups is prevented by the problematic ambient conditions of the papermaking machine's basic unit assembly groups, where the occurrence of high temperatures, moisture and harmful concentrations prevents the locating of sensitive electronic components. The present encapsulation of the machine control system does not provide adequate protection against ambient conditions, nor is any monitoring associated with protection arranged for the electromechanical equipment used today. For this reason, the input/output units and control units of the machine control system are located outside the machine's basic unit assembly groups, where suitable conditions for computer and electronic components can easily be arranged. Moreover, document EP 0 234 518 A2 discloses an improved system for controlling a web property profiling apparatus, wherein a plurality of actuators for selectively altering an environment of a web to which the actuators are exposed are arranged to be spaced across the web profiling apparatus and are connected so that the actuator control signals are conveyed to a control apparatus by means of a serial communication line. The control means selectively outputs signals for driving in a predetermined manner the actuators connected thereto. The connection is provided by a single coaxial cable for linking the control means to each of the plurality of actuator drivers, the drivers being directly connected to the actuators. The actuator drivers are located in close proximity to the connected actuators on the web property profiling apparatus. Each actuator is surrounded by a housing which environmentally protects the driver. The housing includes two layers which are spaced apart from each other to form a chamber therebetween, and a fluid passed through the chamber to remove incoming and generated heat from the actuator drivers. Furthermore, document US 5 771 174 discloses a distributed intelligence actuator controller with peer-to-peer actuator communication, wherein a local area network is used to connect a series of actuators together and to perform communication with a supervisory central control system. The communication is performed from actuator to actuator and a corresponding algorithm resident in each actuator can make target value decisions based on information received from its peers. The actuators are positioned and arranged at spaced apart locations and each actuator is individually controllable and adjustable in response to control signals. Each actuator is additionally connected to an intelligent actuator controller being operatively associated with a corresponding actuator of the plurality of actuators. Communication is performed between the actuator controllers and the supervisory general control system thereby providing a distributed intelligence control system. It is a purpose of the present invention to bring about an arrangement, wherein the input/output units and/or process control units of the machine control system can be located in connection with the papermaking machine's basic unit assembly groups. It is an another purpose of the invention also to bring about such an arrangement, wherein the units of the machine control system are located in connection with the papermaking machine's basic unit assembly groups in a compartment, wherein the temperature and moisture conditions within the protected compartment are monitored. In addition, it is a purpose of the present invention to bring about such a method, by which cabling is reduced between the process control and input/output units of the machine control system and the controlled actuators located in the basic unit assembly groups. An additional purpose of the invention is to bring about such a method, by which the input/output units of the machine control system are located in connection with the basic unit assembly groups of the papermaking machine. An additional purpose of the invention is to bring about such a method, by which the process control units of the machine control system are located in connection with the basic unit assembly groups of the papermaking machine. An additional purpose of the invention is to bring about such a method, by which the process control units and/or input/output units of the machine control system to be located in connection with the basic unit assembly groups of the papermaking machine are protected against stresses and vibrations from the existing environment. An additional purpose of the invention is to bring about such a method, by which the cabling between the machine control system and the equipment to be connected therewith is performed and tested before the papermaking machine is delivered to the customer. According to the present invention the above purposes and objects are accomplished by a method of controlling a papermaking machine, a board machine or tissue machine as well as a machine control system of a papermaking machine, a board machine or tissue machine as set out in the appended claims. The method according to the invention is characterised mainly in that in the method the process control units and/or input/output units of the machine control system are located in a mechanical machine part in connection with the basic unit assembly groups of the papermaking machine/board machine/tissue machine or such. The integrated machine control module according to the invention is characterised in that the integrated machine control module includes an internal cabinet, wherein the process control units and/or input/output units of the machine control system are located, and in that in the said internal cabinet means are arranged for monitoring ambient conditions as well as means for eliminating stresses caused by ambient conditions in such a way that the integrated machine control module can be located in ambient conditions existing in connection with the basic unit assembly groups of the papermaking machine. Locating the input/output units and/or process control units of the machine control system in connection with the basic unit assembly groups of the papermaking machine will reduce cabling work considerably and will save cable material between the input/output units and the controlled equipment. At the same time, a considerable reduction is achieved in the installation delivery cycle. On the installation site, cabling need be arranged only for the voltage supply and for the bus connection between a part of the centralised system and the input/output units. In the arrangement according to the invention, the units of the machine control system are located in connection with the papermaking machine's mechanical basic unit assembly groups, hydraulic centres or other such entities in the same assembly with other automation. Basic unit assembly groups of the papermaking machine are e.g. the headbox, the wire section, the press, the drying section, the on-line/off-line coating units, the on-line/off-line calender and other finishing machines. In the location according to the invention, the process control units and input/output units are protected against temperature, moisture and vibration stresses from the environment by an encapsulation suitable for the purpose. In the arrangement according to the invention, the units of the machine control system are encapsulated in such a way that temperature measurement, monitoring, pressure measurement and removal of accumulated moisture are arranged within the capsule. Lead-ins of the cabling are arranged to be tight by preventing air around the capsule from entering through the lead-ins. In the arrangement according to the invention, the units of the machine control system are protected in such a way that their reliable operation will remain at least at the present level, although the ambient conditions of the place of location according to the invention become considerably more difficult compared with earlier practice. In the following, the invention will be described in greater detail with reference to the appended drawings, wherein: Figure 1 is a block diagram of a papermaking machine's state-of-the-art machine control system. Figure 2 is a block diagram of a machine control system according to the invention, wherein the input/output units are located in connection with basic unit assembly groups of the papermaking machine. Figure 3 is a block diagram of a machine control system according to the invention, wherein the input/output units and the process control units are located in connection with basic unit assembly groups of the papermaking machine. Figure 4 shows an example of the location of input/output units and/or process control units of the machine control system in connection with basic unit assembly groups of the papermaking machine. Figure 5 shows an example of the papermaking machine's basic unit modules, each one of which is controlled by an integrated machine control method in accordance with the invention. Figure 6 shows an integrated machine control module according to the invention. Figure 1 shows in block diagram form the machine control system of a papermaking machine, which includes process control units PCS, input/output units I/O, central processing units CPU as well as a data communication bus C connecting these. From input/output units I/O cabling L1...Ln is drawn to basic unit assembly groups U 1 ...U n of the papermaking machine, which are e.g. a headbox, a wire section, a press, a drying section, on-line/off-line coating units, an on-line/off-line calender and other finishing machines. The machine control system controls actuators located in these, e.g. valves or pneumatically operating machine parts. Cabling L1...Ln may include tens or hundreds of twin wires, wherein a binary/analog signal is travelling. According to the state of the art, the process control units PCS and input/output units I/O of the machine control system are located in an assembly compartment A shown by a dashed line, which is located separately from the basic unit assembly groups of the papermaking machine. Temperature and moisture conditions favourable for computer components exist in assembly compartment A. Between input/output units I/O and basic unit assembly groups U 1 ...U n there is bi-directional control cabling L1...Ln, which transports the control signal from input/output unit I/O to the controlled equipment and the monitoring signal from the controlled equipment to input/output unit I/O. The actuators to be controlled which are located in each basic unit assembly group U 1 ...U n are marked by reference numbers D 11 ...D 1m ; ...; D n1 ...D nm . The actuators D 11 ...D 1m ;...; D n1 ...D nm to be controlled may be located e.g. in the headbox, in the press, on the wire section, in the drying section, in the coating unit, in the calender, in the reel-up, in the cutter or in other finishing machines Figure 2 shows in block diagram form a machine control system, wherein the input/output units I/O are located in connection with the papermaking machine's basic unit assembly groups U 1 ...U n in protected compartments, which in Figure 2 are indicated by dashed line areas B 1 ...B n . The units located in the dashed line areas are located in a protected cabinet or capsule or such in connection with each basic unit assembly group U 1 ...U n of the papermaking machine, so that the cabling between input/output units I/O and the controlled equipment D 11 ...D 1m ;...; D n1 ...D nm may be installed and tested beforehand at the paper machine plant. The connection between input/output units I/O and process control units PCS is formed by data communication bus C'. Figure 3 shows a machine control system according to the invention, wherein both the process control units PCS and the input/output units I/O are located in protected compartments (dashed line areas B 1 ... B n ) located in connection with basic unit assembly groups U 1 ...U n of the papermaking machine. Into process control units PCS located in the protected compartment B 1 ...B n of each basic unit assembly group U 1 ...U n a data communication bus C is introduced, which forms a connection between process control units PCS and the other parts of the machine control system. The connection between process control units PCS and input/output units I/O is brought about by a data communication bus C'. The process control units PCS located in each basic unit assembly group U 1 ...U n also communicate with each other through data communication bus C. With the method according to the invention, it is possible of the components PCS, I/O of the machine control system located in the papermaking machine's basic unit assembly groups to form an integrated machine control module, which is located in a protected compartment. Figure 4 shows an example of a papermaking machine's wire section, wherein two integrated machine control modules I1, I2 are located in connection with the papermaking machine's basic unit assembly group in a compartment, wherein input/output units I/O and/or process control units PCS (the components located within the dashed line areas B 1 ...B n in Figure 2 or 3) are located. The input/output units I/O and/or process control units PCS belonging to the machine control system are typically located in connection with basic unit assembly groups U 1 ... U n so that in the same connection there are also the components of hydraulics, pneumatics, lubrication, vibration control and electronics, to which the integrated machine control module is connected. Figure 4 shows an example of the wire section of a papermaking machine, wherein two integrated machine control modules I1, I2 are located in connection with the basic unit assembly groups of the papermaking machine in a compartment, wherein input/output units I/O and/or process control units PCS are located. The input/output units I/O and/or process control units PCS belonging to the machine control system are typically located in connection with basic unit assembly groups U 1 ...U n so that in the same connection there are also the components of hydraulics, pneumatics, lubrication and electronics as well as the vibration control components, to which the integrated part of the machine control system is connected. In the examples shown in Figure 4, the integrated machine control module I1 and I2 controls and measures/monitors e.g. electrically, hydraulically or pneumatically operating actuators (regulating valves, magnetic valves), limit switches, pressure transmitters, temperature transmitters, and others, such as vibration sensors, position sensors and such. Figure 5 shows an example of a papermaking machine's structural entities, each one of which can be controlled by one integrated machine control module of the machine control system located in the basic unit assembly group, which integrated machine control module includes process control and/or input/output units. In the example shown in Figure 5, the basic unit assembly group of the papermaking machine includes six mechanical structural blocks U 1 ...U 6 , in each one of which an own integrated machine control module may be located. These integrated machine control modules are connected with each other by a data communication bus, whereby they may exchange data on the functions or state of each other. Each integrated machine control module is also connected with the others parts of the machine control system by the data communication bus. Figure 6 shows an integrated machine control module I according to the invention, which preferably includes double encapsulation, so that within an external cabinet 20 an internal cabinet 10 is located, wherein the machine control system's input/output units I/O are located, from which control cables L1...Ln are arranged to the controlled equipment. The machine control system's process control units PCS may also be located in the internal cabinet, but these may also be located in a separate assembly compartment outside the basic unit assembly groups of the papermaking machine. The double encapsulation efficiently prevents the electronic components located in internal cabinet 10 from being exposed to ambient conditions. Hydraulic, pneumatic and electric equipment relating to the papermaking machine's automation may be located in the external cabinet 20 outside internal cabinet 10, possibly similarly protected, whereby they will be in the same mechanical assembly as the units of the machine control system. Lead-in of the cables required in the integrated machine control module I is arranged through tight lead-ins t into external cabinet 20 and further through leadins t' into internal cabinet 10. A power supply cable P, data communication bus C (system bus or I/O bus) and control cables L1...Ln for the controlled equipment are brought into the integrated machine control module I. Input/output units I/O and process control units PCS are typically in the form of electronic cards, which are installed in electronics frame E. To frame E the data communication bus C is brought from the machine control system, through which bus C the units of the integrated machine control system communicate with the other parts of the machine control system and with other systems of the papermaking machine, such as e.g. the electric drives or the quality control system. Electronics frame E within internal cabinet 10 is equipped with vibration dampers d, which protect units to be connected to electronics frame E against disturbing vibrations caused by the papermaking machine environment. Through external cabinet 20 supply channel 15 for trimming air is brought into internal cabinet 10, which channel supplies trimming air continuously into internal cabinet 10. The supply channel 15 for trimming air is equipped with a pressure reducer 16, which is used for regulating a suitable flow rate of trimming air. The air supplied to internal cabinet 10 flows through internal cabinet 10 and exits by way of fitting 25. The small airflow through internal cabinet 10 will remove moisture and other impurities entering the cabinet during maintenance. The flow-through causes a slight overpressure in external cabinet 20, whereby removal through condensation water exit opening 26 of water condensing in external cabinet 20 will become more efficient. A temperature detector 11 and a moisture detector 12 are located within internal cabinet 10 for use in monitoring that conditions within internal cabinet 10 will remain suitable for the operation of the machine control system's units. Temperature and moisture detectors 11, 12 may be provided with transmitters, which send temperature and moisture data to the monitoring unit. In case permissible temperature and moisture limits are exceeded, the papermaking machine's monitoring system will receive an alarm. Typically, leaving the door of the integrated machine control module I open will result in an alarm. Although the invention was described in the foregoing by way of example in connection with a wire section, the invention may also be applied just as well in other basic unit assembly groups. The following is a presentation of claims defining the inventive idea, within the scope of which various details of the invention may vary and depart from the above presentation given only as an example. The invention relates to a method for controlling a papermaking machine/board machine/tissue machine or such, which papermaking machine/board machine/tissue machine or such includes basic unit assembly groups, such as a headbox, a wire section, a press, a drying section, a coating unit, a finishing machine, etc. The machine control system of the papermaking machine/board machine/tissue machine or such comprises a central processing unit (e.g; a unit for control room, alarm and other such functions), one or more process control units, and one or more input/output units, which are connected by control cables to the controlled units or actuators. In the method the process control units and/or input/output units of the machine control system are located in a mechanical machine part in connection with basic unit assembly groups of the papermaking machine/board machine/tissue machine or such. The invention also relates to an integrated machine control module in the machine control system of a papermaking machine/board machine/tissue machine or such. The integrated machine control module comprises an internal cabinet, wherein the process control units and/or the input/output units of the machine control system are located. Said internal cabinet equipment is arranged for monitoring ambient conditions as well as equipment for removing stresses caused by ambient conditions in such a way that the integrated machine control module can be located in ambient conditions existing in connection with basic unit assembly groups of the papermaking machine.

Claims: A method of controlling a papermaking machine, board machine or tissue machine, which papermaking machine, board machine or tissue machine includes basic unit assembly groups (U 1 ...U n ), such as a headbox, a wire section, a press, a drying section, a coating unit or a finishing machine, and wherein a machine control system of the papermaking machine, board machine or tissue machine includes a central processing unit (CPU), one or more process control units (PCS) connected to said central processing unit (CPU), and one or more input/output units (I/O), connected by control cables (L1... Ln) to the controlled units or actuators (D 11 ... D 1m ; D n1 ... D nm ), comprising the steps of: connecting said process control units (PCS) located in connection with said basic unit assembly groups (U 1 ... U n ) of said papermaking machine to one another by a data communication bus (C), connecting said input/output units (I/O) located in connection with said basic unit assembly groups (U 1 ... U n ) of said papermaking machine to said process control unit (PCS) by a data communication bus (C'), housing the process control units (PCS) and/or the input/output units of the machine control system in an internal cabinet, locating said process control units (PCS) and/or input/output units (I/O) of the machine control system within a mechanical machine part in the basic unit assembly groups of the papermakingmachine, board machine or tissue machine, and locating said process control units (PCS) and/or said input/output units (I/O) in connection with basic unit assembly groups (U 1 ... U n ) of said papermaking machine in a same compartment as hydraulics, pneumatics, electricity, or vibration control automation, monitoring ambient conditions within the cabinet, protecting said process control units (PCS) and/or said input/output units (I/O) against ambient conditions, such as temperature variations, vibration, moisture and impurities by protective encapsulation and connecting said control cables (L1 ... Ln) with said input/output units (I/O) at a paper machine plant, and removing stresses caused by said ambient conditions in such a way so that said integrated machine control module (I) is located in ambient conditions existing in connection with basic unit assembly groups of said papermaking machine. The method as defined in claim 1, further comprising the step of: connecting said process control units (PCS) and said input/output units (I/O) located in connection with basic unit assembly groups (U 1 ... U n ) of said papermaking machine to at least one of a remaining machine control system through a data communication bus (C). A machine control system of a papermaking machine, board machine or tissue machine, which papermarking machine, board machine or tissue machine includes basic unit assembly groups (U 1 ... U n ), such as a headbox, a wire section, a press a drying section, a coating unit or a finishing machine, and wherein the machine control system includes an integrated machine control module, which machine control system includes a central processing unit (CPU), one or more process control units (PCS) connected to said central processing unit (CPU), and one or more input/output units (I/O), connected by control cables (L1 ... Ln) to the controlled units or actuators (D 11 ... D 1m ; D n1 ... D nm ), wherein data communication connections (C) are between the central processing unit (CPU), the process control units (PCS) and the input/output units (I/O), said process control units (PCS) and/or input/output units (I/O) of the machine control system being located within a mechanical machine part in the basic unit assembly groups of the papermaking machine, board machine or tissue machine, being located in connection with basic unit assembly groups (U 1 ... U n ) of said papermaking machine in a same compartment as hydraulics, pneumatics, electricity, or vibration control automation and being protected against ambient conditions by protective encapsulation, wherein the integrated machine control module comprises : an internal cabinet (10) for housing said process control units (PCS) and/or said input/output units (I/O) of said machine control system therein; monitoring means structured and arranged within said internal cabinet (10) for monitoring ambient conditions within said cabinet, and stress removing means for removing stresses caused by said ambient conditions in such a way so that said integrated machine control module (I) is located in ambient conditions existing in connection with basic unit assembly groups of said papermaking machine. The machine control system as defined in claim 3, wherein said process control units (PCS) and/or said input/output units (I/O) of said machine control system are attached to an electronics frame (E). The machine control system as defined in claim 4 wherein said electronics frame (E) is protected by vibration dampers (d). The machine control system as defined in claim 3, further comprising: a temperature, moisture and/or vibration detector (11) structured and arranged within said internal cabinet (10). The machine control system as defined in claim 3, further comprising: a pressure detector (12) structured and arranged in said internal cabinet (10). The machine control system as defined in claim 3, further comprising: a flow-through of trimming air structured and arranged in said internal cabinet (10). The machine control system as defined in claim 8, further wherein said trimming air is brought into said internal cabinet (10) through a supply channel (15). The machine control system as defined in claim 9, further comprising: a pressure regulator (16) connected to said supply channel (15) in order to regulate the flow rate of the trimming air. The machine control system as defined in claim 3, further comprising: a plurality of tight cable lead-ins (t') for a power supply cable (P), for control cables (L1... Ln) of said equipment to be controlled by said machine control system and for said data communication bus cable (C) arranged within said internal cabinet (10). The machine control system as defined in claim 3, further comprising: a trimming air flow detector (12) for monitoring and ensuring that a door of said internal cabinet (10) remains closed. The machine control system as defined in claim 3, wherein said internal cabinet (10) is located within an external cabinet (20). The machine control system as defined in claim 13, wherein said external cabinet (20) further comprises: a condensation water removal system (26). The machine control system as defined in claim 13, further comprising: a plurality of tight cable lead-ins (t) structured and arranged in said external cabinet (20) for passage of a power supply cable (P), a plurality of control cables (L1... Ln) of said equipment to be controlled by said machine control system and for a data communication bus cable (C).

Inventors: FAGERLUND JOHN, VAEHAETALO HARRI, FAGERLUND, JOHN, VAEHAETALO, HARRI, Vähätalo, Harri
Applicants: METSO PAPER INC, METSO PAPER, INC.
Application year: 2000
Main classification: D21G9
IPC codes: D21G9, D21F7