JP2017091181A - Field apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a field apparatus that prevents traffic from increasing on a communication path and can precisely calculate a management index.SOLUTION: A field apparatus 100 includes sensors 110 and 115, a process value calculation unit 131, and a management index calculation unit 132. The sensors 110 and 115 output measurement values obtained by measuring measurement objects in a plant at a first cycle. The process value calculation unit 131 calculates a process value on the basis of the measurement values output by the sensors 110 and 115. The management index calculation unit 132 calculates a management index used for diagnosis of the plant at a second cycle longer than the first cycle using the calculated process value.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a field device installed in a plant.

  Conventionally, in plants, factories, and the like (hereinafter referred to as “plants” when these are collectively referred to), field devices (measuring instruments, operation devices) called field devices and controllers that control them are connected. A distributed control system (DCS) has been established, and advanced automatic operation has been realized.

  In a plant in which such a distributed control system is constructed, for example, field devices transmit measured values (flow rate, pressure, temperature, etc.) to external devices, and external devices are abnormal based on measured values received from field devices. Diagnosis is performed (see, for example, Patent Documents 1 and 2).

JP 2010-218301 A Special table 2008-535106 gazette

  However, since the measurement cycle of the field device is short, when the field device transmits a measurement value to the external device every measurement cycle, traffic on the communication path may increase. In order to prevent an increase in traffic, when a field device attempts to thin out a measured value and send it to the controller, the real-time property of the measured value is lost, and a management index used for diagnosis of the plant may not be accurately calculated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a field device capable of accurately calculating a management index while preventing an increase in traffic on a communication path.

A field device (100) according to claim 1 of the present invention is a field device installed in a plant, and outputs a measurement value obtained by measuring a measurement object in the plant in a first period. Using a sensor (110, 115), a process value calculation unit (131) that calculates a process value based on the measurement value output from the sensor, and the process value calculated by the process value calculation unit, A management index calculation unit (132) that calculates a management index used for diagnosis of the plant in a second period longer than the first period.
A field device according to a second aspect of the present invention is the field device according to the first aspect, wherein the management index calculation unit calculates the management index by performing a multiple regression calculation using the process value. 133).
The field device according to claim 3 of the present invention is the field device according to claim 2, wherein the storage unit (120) stores a coefficient of a multiple regression equation calculated by the multivariate analysis unit performing multivariate analysis in advance. It further includes a signal input unit (155) to which an external signal output from an external device is input, and the multivariate analysis unit is calculated by the coefficient stored in the storage unit and the process value calculation unit. The management index is calculated by performing multiple regression calculation using the process value and the external signal input to the signal input unit.
A field device according to a fourth aspect of the present invention is the field device according to the second or third aspect, wherein the multivariate analysis unit determines the state of the plant based on the calculated management index.
The field device according to claim 5 of the present invention further includes a display unit (140) for displaying the state of the plant determined by the multivariate analysis unit in claim 4.
The field device according to claim 6 of the present invention further includes a state output unit (150) for outputting the state of the plant determined by the multivariate analysis unit to an external device in claim 4 or 5.
The field device according to claim 7 of the present invention is the maintenance management unit (134) according to claim 1 or 2, wherein the management index calculation unit calculates maintenance management information used for maintenance management of the plant as the management index. ).
The field device according to an eighth aspect of the present invention is the field device according to the seventh aspect, wherein the maintenance management unit uses the average value and the standard deviation of the process values to obtain the upper limit management value and the lower limit management value of the measurement value. Calculated as a management index.
The field device according to claim 9 of the present invention is the field device according to claim 8, wherein the maintenance management unit determines that the process value calculated by the process value calculation unit is larger than the upper limit management value, or the process value is When it is smaller than the lower limit management value, it is determined that an abnormality has occurred in the plant.
In the field device according to claim 10 of the present invention, an abnormality has occurred in the plant in accordance with the determination in claim 9 that an abnormality has occurred in the plant by the maintenance management unit. It further has a display unit (140) for displaying the above.
A field device according to claim 11 of the present invention outputs alarm information to an external device in accordance with claim 9 or 10 when the maintenance management unit determines that an abnormality has occurred in the plant. And a status output unit (150).

  According to the field device of the present invention, it is possible to prevent an increase in traffic on the communication path and accurately calculate a management index.

1 is a block diagram illustrating an overall configuration of a plant control system 1. FIG. 2 is a block diagram illustrating an example of a detailed configuration of a field device 100. FIG. FIG. 10 is a diagram for explaining management index calculation processing by a multivariate analysis unit 133; FIG. 6 is a diagram for explaining management index calculation processing by a maintenance management unit 134; It is a flowchart which shows a management parameter | index calculation process. It is a flowchart which shows the process by the multivariate analysis part 133. 5 is a flowchart showing processing by a maintenance management unit 134.

  Hereinafter, field devices according to embodiments will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the overall configuration of the plant control system 1. The plant control system 1 is a control system that performs monitoring and control of a plant. Plants include, for example, chemical and other industrial plants, plants that manage and control wells in and around gas fields and oil fields, plants that manage and control power generation such as hydropower, thermal power, and nuclear power, solar power, wind power, etc. There are plants that manage and control energy harvesting, and plants that manage and control water and sewage and dams.

  As shown in FIG. 1, the plant control system 1 includes a field device 100, an I / O module 200, a controller 300, and an operation monitoring terminal 400. The field device 100 includes a measuring device 100a such as a flow meter or a temperature sensor, and an operating device 100b such as a valve device or an actuator device. Hereinafter, when it is not distinguished which “field device”, it is simply expressed as a field device 100. In FIG. 1, two field devices are shown, but three or more field devices may be installed in the plant.

  The field device 100 is connected to an I / O port provided in the I / O module 200 via a transmission line L. The transmission line L is, for example, a transmission line used for transmitting an analog signal of “4 to 20 mA”, a transmission line used for transmitting a pulse signal of “0 to 1 kHz”, and a contact provided inside the field device 100. Including a transmission line that transmits a High signal / Low signal by turning ON / OFF the signal. The field device 100 transmits signals such as measured process values (for example, flow rate and temperature) to the I / O module 200 via the transmission line L.

  The field device 100 and the I / O module 200 are, for example, a wired industrial network that conforms to HART (registered trademark), FieldBus, or the like, or a wireless industrial network that conforms to ISA100.11a, WirelessHART (registered trademark), or the like. It may be connected with.

  The I / O module 200 is provided between the field device 100 and the controller 300. A plurality of field devices 100 can be connected to the I / O module 200. The I / O module 200 processes signals transmitted / received between the connected field device 100 and the controller 300. For example, a process of converting a signal received from the field device 100 (an analog signal such as a “4 to 20 mA” signal and a digital signal superimposed on the analog signal) into a signal that can be received by the controller 300 is performed. The I / O module 200 transmits the converted signal to the controller 300 via the cable C.

  The controller 300 and the operation monitoring terminal 400 are connected to the network N. The network N is, for example, a wired network such as Ethernet (registered trademark), but wireless communication conforming to a wireless communication standard such as Wi-Fi (registered trademark), WiMAX (registered trademark), 3G / LTE (registered trademark), or the like. May be a wireless network.

  The controller 300 controls the field device 100 by performing process control communication with the field device 100 in accordance with an instruction from the operation monitoring terminal 400. Specifically, the controller 300 acquires a process value measured by a certain field device 100 (for example, the sensor device 100a), calculates an operation amount of the other field device 100 (for example, the valve device 100b), and transmits it. Thus, the other field device 100 (for example, the valve device 100b) is controlled.

  The operation monitoring terminal 400 is a terminal that is operated by an operator such as a plant and used for process monitoring. For example, the operation monitoring terminal 400 acquires data (for example, a process value) transmitted from the field device 100 from the controller 300 and transmits the behavior of the field device 100 or the controller 300 to the operator, and based on an instruction from the operator. The controller 300 is controlled.

  FIG. 2 is a block diagram illustrating an example of a detailed configuration of the field device 100. In FIG. 2, as an example of the field device 100, a block diagram of a flow meter that measures the flow rate of the fluid in the pipe is shown. The field device 100 includes a flow sensor 110, a temperature sensor 115, a storage unit 120, a control unit 130, a display unit 140, a signal output unit 145, a state output unit 150, a signal input unit 155, and a state input. Part 160.

  The flow sensor 110 is a sensor that measures the flow rate of the fluid in the pipe and supplies a signal indicating the measured value (flow rate) to the control unit 130. The temperature sensor 115 is a sensor that measures the temperature of the fluid in the pipe and supplies a signal indicating the measured value (temperature) to the control unit 130. The flow sensor 110 and the temperature sensor 115 supply measured values to the control unit 130 at a sampling period of 50 [msec], for example.

  The storage unit 120 is a memory used by the control unit 130 and is realized by, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD (Hard Disk Drive), a flash memory, or the like.

  The control unit 130 includes a processor such as a CPU (Central Processing Unit) and a program memory that stores programs, and controls the entire field device 100. The control unit 130 includes a process value calculation unit 131 and a management index calculation unit 132.

  The process value calculation unit 131 calculates a process value (flow rate data) by performing signal processing such as filtering and moving average on the measurement value supplied from the flow rate sensor 110. The process value calculation unit 131 calculates a process value (temperature data) by performing signal processing such as filtering and moving average on the measurement value supplied from the temperature sensor 115. The process value calculation unit 131 supplies the calculated process value to the management index calculation unit 132 and the signal output unit 145.

  The management index calculation unit 132 uses the process value supplied from the process value calculation unit 131 to calculate a management index. The management index is an index used for diagnosis of the plant, for example, an index indicating the lining thinning amount of piping in the plant, the quality or yield of the product.

  The management index calculation unit 132 includes a multivariate analysis unit 133 and a maintenance management unit 134. Although described in detail later, the multivariate analysis unit 133 calculates a management index by performing multiple regression calculation using the process values (flow rate data and temperature data) supplied from the process value calculation unit 131. The multivariate analysis unit 133 supplies the calculated management index to the signal output unit 145. In addition, the multivariate analysis unit 133 determines the state of the plant based on the calculated management index, and supplies information indicating the state of the plant to the display unit 140 and the state output unit 150.

  Although the details will be described later, the maintenance management unit 134 uses the process values (flow rate data and temperature data) supplied from the process value calculation unit 131 to produce maintenance management information (for example, manufactured in the plant) necessary for plant maintenance management. Information necessary for yield control and quality control of the product to be calculated) is calculated as a management index. The maintenance management unit 134 determines whether an abnormality has occurred in the plant based on the calculated management index. When an abnormality has occurred in the plant, the maintenance management unit 134 supplies alarm information to the display unit 140 and the state output unit 150.

  The display unit 140 is a display device such as a liquid crystal display device, for example, and displays information indicating the state of the plant supplied from the multivariate analysis unit 133 or the maintenance management unit 134.

  The signal output unit 145 receives, for example, the process value supplied from the process value calculation unit 131 and the management index supplied from the management index calculation unit 132 via the transmission line L used for transmitting the “4 to 20 mA” signal. Transmit to the I / O module 200. The signal output unit 145 transmits the process value and the management index to the I / O module 200 at a cycle of 1 [sec], for example.

  The I / O module 200 converts the management index received from the signal output unit 145 into a signal that can be received by the controller 300 and transmits the signal to the controller 300. The signal output unit 145 may transmit the process value and the management index via the transmission line L used for transmitting the pulse signal instead of the transmission line L used for transmitting the “4 to 20 mA” signal. .

  The state output unit 150 transmits the state information indicating the state of the plant supplied from the multivariate analysis unit 133 and the alarm information supplied from the maintenance management unit 134 to the I / O module 200 via the transmission line L. For example, the status output unit 150 transmits alarm information and the like to the I / O module 200 by using a transmission line L that transmits a High signal / Low signal by turning on / off a contact provided inside the field device 100. Send.

  As described above, the status output unit 150 transmits alarm information and the like to the I / O module 200 using the transmission line L of a system different from the transmission line L used by the signal output unit 145. Thus, it is possible to prevent an increase in traffic on the transmission line L used by the signal output unit 145 and to transmit alarm information to the I / O module 200 immediately.

  The status output unit 150 may not only transmit alarm information to the controller 300 via the I / O module 200 but also transmit alarm information to other field devices 100 via the I / O module 200. . Thereby, alarm information can be shared between field devices.

  An external signal transmitted from the external device is input to the signal input unit 155. For example, an external signal output from an external device is input to the signal input unit 155 via the transmission line L used for transmitting the “4 to 20 mA” signal. Note that the signal input unit 155 may receive an external signal via the transmission line L used for transmitting the pulse signal instead of the transmission line L used for transmitting the “4 to 20 mA” signal. The signal input unit 155 supplies the input external signal to the control unit 130.

  Alarm information transmitted from an external device such as another field device 100 is input to the state input unit 160. For example, the status input unit 160 transmits alarm information and the like from the I / O module 200 by using the transmission line L that transmits a High signal / Low signal by turning ON / OFF a contact provided in the field device 100. Receive.

  As described above, the status input unit 160 receives alarm information and the like from the I / O module 200 using the transmission line L of a system different from the transmission line L used by the signal input unit 155. Thus, it is possible to prevent an increase in traffic on the transmission line used by the signal input unit 155 and to receive alarm information from the I / O module 200 immediately.

  Next, the multiple regression calculation by the multivariate analysis unit 133 will be described. The multivariate analysis unit 133 performs multiple regression calculation using the coefficient calculated by performing multivariate analysis in advance, the process value supplied from the process value calculation unit 131, and the external signal input to the signal input unit 155. . The multivariate analysis unit 133 calculates a management index (for example, an index indicating the lining thinning amount of piping in the plant, the quality or yield of the product) by performing multiple regression calculation.

  FIG. 3 is a diagram for explaining management index calculation processing by the multivariate analysis unit 133. Hereinafter, the case where the lining thinning amount of piping is calculated as the management index Y will be described. The “lining thinning amount” is a management index representing the thinning amount [mm / year] of the coating member inside the pipe.

  First, the flow sensor 110 measures the flow rate of the fluid in the pipe and supplies a signal indicating the measurement value (flow rate) to the process value calculation unit 131. The temperature sensor 115 measures the temperature of the fluid in the pipe and supplies a signal indicating the measurement value (temperature) to the process value calculation unit 131.

  The process value calculation unit 131 calculates a process value (flow rate data X1) based on the measurement value supplied from the flow sensor 110, and at the same time, calculates a process value (temperature data X2) based on the measurement value supplied from the temperature sensor 115. Is calculated. The process value calculation unit 131 supplies the calculated flow rate data X1 and temperature data X2 to the multivariate analysis unit 133.

  On the other hand, the process value (slurry hardness data X3) output from the external device is input to the signal input unit 155. The external device may be another field device 100 that measures the slurry hardness of the fluid in the pipe, or may be an input device such as a keyboard that receives input of the slurry hardness from the user. The signal input unit 155 supplies the received slurry hardness data X3 to the multivariate analysis unit 133.

  The multivariate analysis unit 133 performs multiple regression calculation using a multiple regression equation. The multiple regression equation is expressed as the following equation (1). In equation (1), the coefficients A0 to A3 are values calculated by the multivariate analysis unit 133 performing multivariate analysis in advance, and are stored in the storage unit 120.

  Y = A0 + A1, X1 + A2, X2 + A3, X3 (1)

  The multivariate analysis unit 133 reads the coefficients A0 to A3 from the storage unit 120. The multivariate analysis unit 133 then reads the coefficients A0 to A3 read from the storage unit 120, the flow rate data X1 and the temperature data X2 calculated by the process value calculation unit 131, and the slurry hardness data supplied from the signal input unit 155. Using X3, the lining thinning amount data Y is calculated as a management index.

  The multivariate analysis unit 133 supplies the calculated lining thinning amount data Y to the signal output unit 145. The signal output unit 145 transmits the lining thinning amount data Y supplied from the multivariate analysis unit 133 to the I / O module 200 via the transmission line L.

  The I / O module 200 converts the lining thinning amount data Y received from the signal output unit 145 into a signal that can be received by the controller 300, and transmits the converted signal to the controller 300 via the cable C. Thereby, the operator of the plant who operates the controller 300 can grasp the lining thinning amount.

  In addition, the multivariate analysis unit 133 determines the state of the plant based on the calculated management index (lining thinning data Y). For example, the multivariate analysis unit 133 determines the state level of the piping in the plant based on the following determination criteria (a) to (e), and derives level data LD indicating the determined state level. The threshold values TH1 to TH4 are preset threshold values according to the thickness of the lining and the like, and TH1 <TH2 <TH3 <TH4.

(A) When Y ≦ TH1: Determination level 1
(B) When TH1 <Y ≦ TH2: Determination level 2
(C) When TH2 <Y ≦ TH3: Determination level 3
(D) When TH3 <Y ≦ TH4: Determination level 4
(E) When Y> TH4: Determination level 5

  The multivariate analysis unit 133 supplies the derived level data LD to the display unit 140. The display unit 140 displays the state level of the piping in the plant based on the level data LD supplied from the multivariate analysis unit 133. The display unit 140 may display the state level with characters or a graphical object such as a bar graph. The plant operator can grasp the state of the pipe by confirming the state level of the pipe displayed on the display unit 140.

  Further, the multivariate analysis unit 133 supplies the derived level data LD to the state output unit 150. The state output unit 150 transmits the level data LD supplied from the multivariate analysis unit 133 to the I / O module 200 via the transmission line L.

  The I / O module 200 converts the level data LD received from the status output unit 150 into a signal that can be received by the controller 300, and transmits the converted signal to the controller 300 via the cable C. Thereby, the plant operator who operates the controller 300 can grasp the state level of the piping in the plant.

  Note that the management index Y calculated by the multivariate analysis unit 133 is not limited to the lining thinning amount data. For example, the multivariate analysis unit 133 may calculate product quality data as the management index Y. In this case, the multivariate analysis unit 133 calculates the quality data Y of the product based on the following formula (2).

  Y = A0 + A1 · X1 + A2 · X2 (2)

  In Expression (2), A0 to A2 are coefficients, X1 is flow rate data, and X2 is pH data. The pH data is data input from an external device to the signal input unit 155, and is data indicating the pH value of the fluid flowing in the pipe. The external device may be another field device 100 that measures the pH value of the fluid in the pipe, or may be an input device such as a keyboard that receives an input of the pH value from the user.

  The multivariate analysis unit 133 calculates the management index Y at a cycle (for example, 1 [sec]) longer than the sampling cycle (50 [msec]) of the flow sensor 110 and the temperature sensor 115. Further, the signal output unit 145 transmits the management index Y to the I / O module 200 at the management index Y calculation period (1 [sec]). Thereby, an increase in traffic on the communication path can be prevented.

  FIG. 4 is a diagram for explaining management index calculation processing by the maintenance management unit 134. The maintenance management unit 134 calculates a management index (for example, an upper limit management value and a lower limit management value) different from the management index (for example, lining thinning amount data and product quality data) calculated by the multivariate analysis unit 133. To do. The management index calculation process performed by the maintenance management unit 134 will be described below.

  The process value calculation unit 131 calculates a process value (flow rate data X1) based on the measurement value supplied from the flow sensor 110, and at the same time, calculates a process value (temperature data X2) based on the measurement value supplied from the temperature sensor 115. Is calculated. The process value calculation unit 131 supplies the calculated flow rate data X1 and temperature data X2 to the maintenance management unit 134.

  The maintenance management unit 134 stores the flow rate data X1 and the temperature data X2 supplied from the process value calculation unit 131 in the storage unit 120. As a result, the storage unit 120 accumulates logs of the flow rate data X1 and the temperature data X2.

  The maintenance management unit 134 calculates a management index based on the flow rate data X1 and the temperature data X2. Hereinafter, as an example, a case where the maintenance management unit 134 calculates the upper limit management value UL and the lower limit management value LL of the flow rate data X1 as management indexes will be described.

  The maintenance management unit 134 reads the log of the flow rate data X1 from the storage unit 120, and calculates the average value Av and the standard deviation σ of the flow rate data X1 based on the read log of the flow rate data X1. Then, the maintenance management unit 134 calculates the upper limit management value UL of the flow rate data X1 based on the equation (3), and calculates the lower limit management value LL of the flow rate data X1 based on the equation (4).

UL = Av + 3 · σ (3)
LL = Av−3 · σ (4)

  Next, when the flow rate data X1 supplied from the process value calculation unit 131 is larger than the upper limit management value UL, the maintenance management unit 134 determines that an abnormality has occurred in the plant, and an abnormality has occurred in the plant. Alarm information AI indicating this is supplied to the display unit 140. In addition, when the flow rate data X1 supplied from the process value calculation unit 131 is smaller than the lower limit management value LL, the maintenance management unit 134 determines that an abnormality has occurred in the plant, and an abnormality has occurred in the plant. Is displayed on the display unit 140.

  The display unit 140 displays that an abnormality has occurred in the plant based on the alarm information AI supplied from the maintenance management unit 134. The plant worker can confirm that the abnormality has occurred in the plant by confirming the display content of the display unit 140.

  When the maintenance management unit 134 determines that an abnormality has occurred in the plant, the maintenance management unit 134 supplies the alarm information AI to the state output unit 150. The status output unit 150 transmits the alarm information AI supplied from the maintenance management unit 134 to the I / O module 200 via the transmission line L.

  The I / O module 200 converts the alarm information AI received from the status output unit 150 into a signal that can be received by the controller 300, and transmits the converted signal to the controller 300 via the cable C. Thereby, the plant operator who operates the controller 300 can grasp that an abnormality has occurred in the plant.

  The maintenance management unit 134 may calculate the upper limit management value UL of the management index Y (for example, lining thinning amount data and product quality data) calculated by the multivariate analysis unit 133 as a management index. .

  In this case, for example, the multivariate analysis unit 133 supplies the calculated lining thinning amount data Y to the maintenance management unit 134. The maintenance management unit 134 calculates the upper limit management value UL of the lining thinning amount data Y supplied from the multivariate analysis unit 133. The maintenance management unit 134 determines that an abnormality has occurred in the plant when the lining thinning amount data Y supplied from the multivariate analysis unit 133 is larger than the upper limit management value UL. When the maintenance management unit 134 determines that an abnormality has occurred in the plant, the status output unit 150 outputs alarm information to the controller 300 via the I / O module 200, and the display unit 140 has an abnormality in the plant. Show what is happening. Thereby, it is possible to calculate a management index for the data calculated by the multivariate analysis unit 133.

  The maintenance management unit 134 accumulates the logs of the flow rate data X1 and the temperature data X2 in the storage unit 120, and has a cycle (for example, 1 [sec]) longer than the sampling cycle (50 [msec]) of the flow rate sensor 110 and the temperature sensor 115. ) To calculate the management index (upper limit management value UL and lower limit management value LL). Further, the status output unit 150 transmits the management index to the I / O module 200 at the management index calculation cycle (1 [sec]). As a result, an increase in traffic on the communication path can be prevented.

  If the process value is transmitted to the controller at a short cycle such as a sensor sampling cycle, traffic on the communication path increases. For this reason, the conventional field device transmits the process value to the controller at a period longer than the sampling period of the sensor by thinning out the process value.

  However, if the process value is thinned out, the real time property of the process value is lost, so the management indices (lining thinning data, product quality data, upper limit management value UL, lower limit management value LL) are accurately calculated. I couldn't. On the other hand, according to the present embodiment, the field device 100 calculates the management index, and transmits the management index at a period longer than the sampling period of the sensor. As a result, the field device 100 according to the present embodiment can prevent an increase in traffic on the communication path and accurately calculate the management index.

  FIG. 5 is a flowchart showing management index calculation processing. The processing according to this flowchart is executed at a cycle of 1 [sec], for example. First, the process value calculation unit 131 acquires the measurement value (flow rate) of the flow sensor 110 and the measurement value (temperature) of the temperature sensor 115 (step S10).

  The process value calculation unit 131 calculates a process value (flow rate data X1 and temperature data X2) based on the measurement value (flow rate) acquired from the flow sensor 110 and the measurement value (temperature) acquired from the temperature sensor 115 (step S11). ). The process value calculation unit 131 supplies the calculated process values (flow rate data X1 and temperature data X2) to the multivariate analysis unit 133.

  A process value (slurry hardness data X3) output from an external device is input to the signal input unit 155. The multivariate analysis unit 133 acquires the process value (slurry hardness data X3) input to the signal input unit 155 (step S12).

  Thereafter, a process by the multivariate analysis unit 133 (to be described later with reference to FIG. 6) (step S13) and a process to be described with reference to the maintenance management unit 134 (step S14) to be described later with reference to FIG. .

  FIG. 6 is a flowchart showing processing by the multivariate analysis unit 133 in step S13 of FIG. First, the multivariate analysis unit 133 reads the coefficients A0 to A3 of the multiple regression equation from the storage unit 120 (step S20). Then, the multivariate analysis unit 133 calculates a management index using a multiple regression equation (step S21). For example, the multivariate analysis unit 133 is supplied from the coefficients A0 to A3 read from the storage unit 120, the process values (flow rate data X1 and temperature data X2) calculated by the process value calculation unit 131, and the signal input unit 155. Using the external signal (slurry hardness data X3), a management index (lining thinning amount data Y) is calculated based on the multiple regression equation shown in the above equation (1).

  The multivariate analysis unit 133 determines the state level of the plant based on the determination criteria (a) to (e) described above, and derives level data LD indicating the determined state level (step S22). The multivariate analysis unit 133 displays the determined state level on the display unit 140 (step S23) and supplies the derived level data LD to the state output unit 150 (step S24). The state output unit 150 transmits the level data LD supplied from the multivariate analysis unit 133 to the controller 300 via the I / O module 200. The above is a series of processing by the multivariate analysis unit 133.

  FIG. 7 is a flowchart showing processing by the maintenance management unit 134 in step S14 of FIG. First, the maintenance management unit 134 reads a log of process values (flow rate data X1) from the storage unit 120 (step S30). Next, the maintenance management unit 134 calculates the upper limit management value UL and the lower limit management value LL as management indexes based on the read log (step S31). For example, the maintenance management unit 134 calculates the upper limit management value UL of the flow rate data X1 based on the aforementioned equation (3), and calculates the lower limit management value LL of the flow rate data X1 based on the aforementioned equation (4).

  The maintenance management unit 134 determines whether or not the process value (flow rate data X1) supplied from the process value calculation unit 131 is greater than the upper limit management value UL (step S32). When the process value (flow rate data X1) supplied from the process value calculation unit 131 is larger than the upper limit management value UL (step S32: YES), the process proceeds to step S34 described later.

  When the process value (flow rate data X1) supplied from the process value calculation unit 131 is equal to or lower than the upper limit management value UL (step S32: NO), the maintenance management unit 134 receives the process value (flow rate) supplied from the process value calculation unit 131. It is determined whether or not the data X1) is smaller than the lower limit management value LL (step S33). When the process value (flow rate data X1) supplied from the process value calculation unit 131 is smaller than the lower limit management value LL (step S33: YES), the process proceeds to step S34 described later. On the other hand, when the process value (flow rate data X1) supplied from the process value calculation unit 131 is equal to or higher than the lower limit management value LL (step S33: NO), the processing according to this flowchart is terminated.

  In step S34, the maintenance management unit 134 displays on the display unit 140 that an abnormality has occurred in the plant (step S34). Thereafter, the maintenance management unit 134 supplies the alarm information AI to the status output unit 150 (step S35). The status output unit 150 transmits the alarm information AI supplied from the maintenance management unit 134 to the controller 300 via the I / O module 200. The above is a series of processing by the maintenance management unit 134.

  As described above, in the present embodiment, the flow rate sensor 110 and the temperature sensor 115 are measured values obtained by measuring the measurement target (flow rate and temperature) in the plant in the first period (50 [msec]). Is output. The process value calculation unit 131 calculates process values (flow rate data and temperature data) based on the measurement values output from the flow sensor 110 and the temperature sensor 115. The management index calculation unit 132 uses the calculated process value to calculate a management index used for plant diagnosis in a second period (1 [sec]) longer than the first period (50 [msec]). To do. As a result, an increase in traffic on the communication path can be prevented, and the management index can be accurately calculated.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 Plant control system, 100 Field apparatus, 110 Flow rate sensor, 115 Temperature sensor, 120 Storage part, 130 Control part, 131 Process value calculation part, 132 Management index calculation part, 133 Multivariate analysis part, 134 Maintenance management part, 140 Display Unit, 145 signal output unit, 150 state output unit, 155 signal input unit, 160 state input unit

Claims (11)

Field equipment installed in the plant,
A sensor that outputs a measurement value obtained by measuring a measurement object in the plant in a first period;
A process value calculation unit that calculates a process value based on the measurement value output from the sensor;
Using the process value calculated by the process value calculation unit, a management index calculation unit that calculates a management index used for diagnosis of the plant in a second cycle longer than the first cycle;
Having field equipment. The field device according to claim 1, wherein the management index calculation unit includes a multivariate analysis unit that calculates the management index by performing multiple regression calculation using the process value. A storage unit for storing a coefficient of a multiple regression equation calculated by performing multivariate analysis in advance by the multivariate analysis unit;
It further has a signal input unit to which an external signal output from an external device is input,
The multivariate analysis unit performs a multiple regression calculation using the coefficient stored in the storage unit, the process value calculated by the process value calculation unit, and the external signal input to the signal input unit. The field device according to claim 2, wherein the management index is calculated. The field device according to claim 2, wherein the multivariate analysis unit determines the state of the plant based on the calculated management index. The field device according to claim 4, further comprising a display unit that displays the state of the plant determined by the multivariate analysis unit. The field device according to claim 4, further comprising a state output unit that outputs the state of the plant determined by the multivariate analysis unit to an external device. The field device according to claim 1, wherein the management index calculation unit includes a maintenance management unit that calculates maintenance management information used for maintenance management of the plant as the management index. The field device according to claim 7, wherein the maintenance management unit calculates an upper limit management value and a lower limit management value of the measurement value as the management index using an average value and a standard deviation of the process values. When the process value calculated by the process value calculation unit is larger than the upper limit management value, or when the process value is smaller than the lower limit management value, the maintenance management unit has an abnormality in the plant. The field device according to claim 8. The field device according to claim 9, further comprising a display unit that displays that an abnormality has occurred in the plant in response to a determination that the abnormality has occurred in the plant by the maintenance management unit. The field device according to claim 9 or 10, further comprising a state output unit that outputs alarm information to an external device in response to a determination that an abnormality has occurred in the plant by the maintenance management unit.

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