JPH0329358Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a paper machine control device used to control paper making/coating processes in the paper manufacturing industry, and particularly relates to an improvement in the display of a monitoring screen.

(Prior Art) The applicant manufactures a paper machine control device,
For example, detailed technical matters are disclosed in Yokogawa Technical Report Vol. 29, p. 195 (1985).

In this papermaking process, there is something called level control. Here, real control means that when a control start command is given by a key command from the operator's station BOPS, the field control station BFCS operates the seed opening valve opening, machine speed, total head pressure, and steam pressure set values. , basis weight detected by a sensor mounted on the frame
Control that changes BW, moisture content MP, ash content, paper machine or coating machine speed, jet wire ratio J/W, and slice opening degree along a predetermined trajectory to target values. The contents of this control include, for example, automatic papermaking speed change and papermaking change control to change the paper type.

Conventionally, when performing level control, a trend screen that displays data such as basis weight, moisture content, ash content, etc. in chronological order, and a sensor that is guided by a frame and scans in the paper width direction and turns back, displays these details. The operator made the decision based on the trend printing.

(Problem that the invention aims to solve) However, it is not easy for the operator to compare the trend screen or trend printout with the target value, so it is necessary to display the current measured value and target value simultaneously to facilitate comparison. There was a request to do so. In particular, no response appears in the trend from the start of control until the dead time of the process has elapsed, making the operator feel uneasy about his or her operation. Furthermore, after the control ends, it is necessary to recognize whether the process continues to operate stably, and it is desired to be able to easily confirm that there is little deviation from the target value.

This invention solves these problems,
It is an object of the present invention to provide a paper machine control device that can easily change the paper making speed and control paper making changes.

(Means for solving the problem) The present invention that achieves the above purpose includes an operator's station that displays the status of the paper making/coating process and gives instructions to the process, and an operator's station that detects the status of this process. A paper machine control device equipped with a sensor and a field control station that controls the paper machine/coating machine based on the target value indicated by the operator's station and the detected value of the sensor, which has the following configuration. be.

That is, the field control station includes a parameter calculation unit that calculates dead time and control end time from the initial state, target value, and control characteristics of the paper machine/coating machine, and a control start signal is sent from the operator's station. A prediction data presentation section is provided for transmitting the target value, the initial state of the sensor and the process, the dead time calculated by the parameter calculation section, and the control end time to the operator's station.

Also, based on the data sent from this predicted data presentation unit, the operator's station
A dead time part that changes in the initial state for the dead time from the time the control starts, a time constant part that changes linearly from the initial state to the target value from the end of the dead time until the control end time, and a time that almost reaches the end of the process after the end of the control time. A prediction display section that displays line-shaped data consisting of a stability monitoring time section that changes at a target value for a period corresponding to a constant, and the state of the sensor or process after the start of control is superimposed on the screen displayed by this prediction display section. A current status display section is provided to display the current status sequentially.

(Function) Each component of the present invention has the following function. The parameter calculation section calculates parameters for roughly displaying the state transition of the process. The predicted data presentation unit transmits parameters from the field control station to the operator's station when necessary.

The prediction display section displays on the screen a polygonal line consisting of a dead time section, a time constant section, and a stability monitoring time section based on the parameters sent from the prediction data presentation section. The current status display section sequentially displays the current values of the process variables over the predicted data, making it clear which area the current control is in.

(Example) The present invention will be explained below using the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 10 is a paper making or coating process, 20 is a sensor that measures the quality of paper,
The paper width direction is scanned at a predetermined period. A field control station 30 includes a parameter calculation section 31 and a predicted data presentation section 32. Reference numeral 40 denotes an operator's station, which includes a prediction display section 41 and a current state display section 42.

To explain the configuration in detail, the parameter calculation section 3
1 inputs the initial state measured by the sensor 20 and the target value instructed from the operator's station 40, and calculates the dead time and control end time based on the control characteristics of the paper making/coating process 10. The predicted data presentation unit 32 starts operating when a level control start signal is transmitted from the operator's station 40, and inputs the initial state measured by the sensor 20 and the target value instructed from the operator's station 40. The dead time and control end time calculated by the parameter calculating section 31 are transmitted to the operator's station 40. This control end time is the dead time when the process is expressed as a first-order delay system plus a time constant.

The prediction display section 41 displays a polygonal line figure based on the data transmitted from the prediction data presentation section 32. The current state display section 42 displays the state of the sensor 20 or the papermaking/coating process 10 after the start of control in chronological order, superimposed on the screen displayed on the prediction display section 41.

FIG. 2 is an explanatory diagram of the data structure, where A is the data sent from the predictive display section 32 to the predictive display section 41 during level control, and B is the data transmitted from the predictive display section 32 to the predictive display section 41 during level control.
This is the SV (set value) or PV (instantaneous value) periodically transmitted from the station 30.

As an initial value from the first prediction data presentation unit 32,
Basic items measured by the sensor 20 such as seed opening valve opening, seed flow rate, total head pressure, steam pressure, machine speed, BW, and MP are transmitted. Since the field control station collects trend data at regular intervals, for example, at 2-second intervals, it transmits this to the current status display section 42.

FIG. 3 is an explanatory diagram of the screen of the operator's station. The polygonal line consists of a dead time part, a time constant part, and a stability monitoring time part. The dead time portion is a straight line that changes in the initial state for the dead time from the start of control. The time constant portion changes linearly from the initial state to the target value after the dead time has elapsed until the control end time, and has a period corresponding to the time constant of the process. The stability monitoring time section is a straight line that changes at the target value during a period that corresponds to the time constant of the process after the elapse of the control end time. The necessary time is secured to determine whether the system is in an unstable state such as hunting. Subsequently, the current status display section 42 sequentially displays the trend data. Data from the start of control to the present is displayed continuously, and the remaining part displays trends that continue to occur.

The operation of the device configured in this manner will be described next. FIG. 4 is an operational diagram at the start of level control. When a start command is received from the operator's station, the field control station transmits the predicted value to the prediction display unit 41 using the prediction data presentation unit 32. Of this data, the operator
Instructs the operator's station to display what is of interest on the screen.

FIG. 5 is an explanatory diagram of trend data. The field control station receives data from the papermaking/coating process 10, BW, MP, etc. from the sensor 20 sent via the communication line.
Periodically transmitted to the operator's station.
Process data is transmitted, for example, at 2-second intervals, and sensor data is transmitted every time the sheet is folded in the paper width direction.

When control is completed and the process status reaches the target value and stabilizes, the end time is displayed on the screen and the data is saved until the next level control.

(Effects of the invention) As explained above, the invention has the following practical effects.

(1) The predicted value is displayed immediately after control is started, and then the instantaneous value is displayed in chronological order, making it easy to monitor the control process.

(2) Since it is divided into the dead time section, time constant and stability monitoring time section, it is easy to understand which mode the current process is in. Especially during the dead time, even if the process is operated, the trend will not change. Even though the impact does not appear, the operator can know when the impact will occur, so the process can be operated with peace of mind.

(3) Stability monitoring The time section displays the time trend required to determine process stability, so the stability (robustness) of the process state after the target value is reached can be monitored.

(4) When the control process becomes easier to see, it becomes easier to collect operating conditions for optimal control, which is useful for optimizing control.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of the data structure, Fig. 3 is an explanatory diagram of the operator's station screen, and Fig. 4 is an explanatory diagram of the screen of the operator's station.
The figure is an operation diagram at the start of level control, and FIG. 5 is an explanatory diagram of trend data. 10...Paper making/coating process, 20...Sensor, 30...Field control station BFCS, 31...Parameter calculation section, 32...
... Prediction data presentation section, 40 ... Operator's station BOPS, 41 ... Prediction display section, 42 ...
...Current status display section.

Claims (1)

[Claims for Utility Model Registration] An operator's station that displays the status of the papermaking/coating process and gives instructions to the process, a sensor that detects the status of this process,
In a paper machine control device equipped with a field control station that controls a paper machine/coating machine based on a target value instructed by the operator's station and a detected value of a sensor, initial conditions, target values, and paper machine/coating machine are controlled. A parameter calculation section calculates dead time and control end time from the control characteristics of the machine tool, and when a control start signal is sent from the operator's station, the parameter calculation section calculates the target value, the initial state of the sensor and the process, The field control station is equipped with a predicted data presentation unit that transmits the dead time and control end time to the operator's station, and based on the data sent from the predicted data presentation unit, the dead time is set in the initial state from the start of control. The time constant part changes linearly from the initial state to the target value from the time the dead time elapses until the control end time, and the time constant part changes at the target value for a period approximately corresponding to the process time constant after the control end time elapses. A prediction display section that displays line-shaped data consisting of a stability monitoring time section, and a current status display section that sequentially displays the sensor or process status after the start of control on the screen displayed by the prediction display section. A paper machine control device provided in a station, characterized by: