JPS6262067A - Method of controlling opening of damper by drive of electric motor - Google Patents

Abstract

PURPOSE:To control opening of a damper efficiently by processing for canceling an instantaneous change in a set opening of a damper, which is set according to fluid pressure and flow rate, and driving the damper. CONSTITUTION:A fluid pressure valve detected by a pressure detector 22 in a pipe 12 is input to an opening setting arithmetic unit 24. The opening setting arithmetic unit 24 outputs an opening signal to a digital controller 10 according to a pressure difference with an external set pressure Po. The digital controller 10 performs average processing for the input opening signal to time, and feeds out an opening adjust signal according to the result to an electric motor 16 through a power supply open-and-close control panel 26. An opening of a damper 14 driven by the electric motor 16 is fed back to the digital controller 10 by an opening sending device 20, and when it reaches a set opening, the operation of the electric motor 16 is stopped.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention relates to a damper opening control method driven by an electric motor, and in particular, a flow of fluid (gas or liquid) is passed through a pipe suitable for regulating or discharging pressure. Detects the pressure of the fluid or the value of the flow device, determines the opening degree to be given to the damper installed in the pipe based on the detected value and the preset value, and calculates the requested setting. The present invention relates to an improvement in a damper opening/control method using an electric motor, in which the damper is driven by an electric motor to control the opening of the damper based on the opening. [Prior Art] Generally, when adjusting the flow rate or pressure of a fluid (gas or liquid) flowing in a pipe, a damper is installed in the pipe and the opening degree of the damper is controlled. ing. If the damper used in this manner has a large diameter or is used under high pressure, a large driving force is required to open and close the damper, so the damper must be driven by an electric motor rather than by air pressure. Incidentally, in order to continuously control the opening degree of the damper, an analog control method is suitable, and a dedicated damper control device is commercially available. However, in such commercially available damper control devices, no standardized method has been established for flexible, horizontal and vertical application to sequence control and speed control of electric motors. On the other hand, as a recent trend, so-called digital IT such as sequencers and programmable logic controllers,
The No. 11 device is becoming the mainstream device for sequentially controlling electric motors. This digital control device is general-purpose and can be applied flexibly and horizontally and vertically to sequence control and speed control of electric motors. Problems that CM Ming attempts to solve] However, the conventional digital control device as described above,
In digitally controlling the drive of the electric motor to control the opening degree of the damper, the following problems or problems have been encountered. (1) In general, fluids have many small fluctuations in pressure or flow rate (and in order to control the opening of a damper that handles such fluid, the pressure or flow n of the fluid must be the standard for opening control). In order to achieve The electric motor must frequently rotate forward or reverse in response to changes in the opening degree, and the electromagnetic switch that turns on and off the power supplied to the electric VJ machine also has to operate frequently. The electric motor and the 11m switch cannot withstand such repeated switching on and off both thermally and mechanically. (2) Continuous damper In the method of driving the electric motor under control using a digital control device as described above, the request for setting the opening degree must be met by only simple movements such as forward rotation, reverse rotation, and stopping of the electric motor. ZQ
There is a difficulty in W. Moreover, when the electric motor is driven, it is difficult to perform accurate positioning due to inertial motion, and therefore it is very difficult to accurately control the opening degree of the damper. (3) The electric motor is suitable for running and stopping by turning on and off the power supply, or for continuous speed aυ control, and therefore does not require opening control and can simply be opened and closed completely. For dampers that are only controlled, the electrical drive system is widely used. However, using an electric motor to control the damper opening is difficult compared to air-driven damper opening control, and has not been generally used. (4) When using such a digitally controlled ag device, the damper opening degree is 1
When used for i1J control, it is necessary to take in a signal of the actual damper opening position as a feedback signal for the control. However, since there is a possibility that an error such as a position signal from a sensor that detects the opening position of the damper deviates over time may occur, the accuracy of the damper opening control becomes poor.

[Purpose 1 of Rmei] The present invention has been made in view of the above-mentioned problems of the conventional art. Another object of the present invention is to provide a method for controlling the damper opening degree by driving an electric motor, in which the opening degree of the damper can be stably and accurately controlled by the fr1 motor. [Means for Solving the Problems] The present invention detects the pressure or flow rate of fluid flowing in a pipe, and adjusts the flow rate of the fluid in the pipe based on the detected value and a preset value. An electric motor drive that determines the set opening degree to be given to the damper installed, and controls the opening degree of the damper by driving the damper bar with an electric machine based on the requested set opening degree. In the damper opening control method according to Find the difference between
The above object is achieved by determining the control (2) to be applied to the damper based on the difference, and controlling the opening degree of the damper by driving the damper with the electric motor based on the control (m). [Operation] In the present invention, the value of the pressure or flow rate of the fluid flowing in the pipe is detected, and based on the detected value and a preset value, it is applied to the damper disposed in the pipe. When controlling the opening degree of the damper by driving the damper electric motor based on the requested opening degree, the instantaneous change in the value of the determined opening degree is canceled. Processing is performed to obtain the essential value of the set opening degree, and to cancel out the instantaneous change with the actual damper opening degree. The difference between the set opening degree and the set opening degree determined by the control is determined, the control all ffi to be applied to the damper is determined based on the difference, and the damper is driven by the electric motor to control its opening degree based on the determined control angle. I try to do that. Therefore, even if the pressure or flow rate of the fluid flowing through the pipe fluctuates, the opening degree of the damper can be controlled stably and accurately.

【Example】

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a damper opening control method using electric motor drive according to the present invention will be described in detail. This embodiment is a damper opening degree control device equipped with a digital controller 10, as shown in FIG. In FIG. 1, a damper 14 is installed in a vibrator 12 through which fluid (gas or liquid) flows, the purpose of which is to adjust the flow rate of the fluid. The damper 1
4 is connected to an electric motor 16 via a shaft, and
A cam limit switch 18 for detecting the fully open and fully open positions of the damper 14 is also connected via a shaft. The electric motor 16 has the damper 1 on an extension of its drive shaft.
An opening transmitter 20 that continuously detects the actual opening HK of No. 4
is provided. On the other hand, a pressure detector 22 for detecting the pressure value P of the fluid is provided behind the damper 14 in the vibrator 12 along the fluid flow direction, and its output is sent to the opening degree setting calculator 24. is input. The opening degree setting 82i calculator 24 compares the externally applied pressure value Pa and the actual pressure value P, calculates an appropriate opening degree SK for the damper 14, and outputs it to the digital controller 10. be.
□The digital controller 10 uses the set opening SK input from the navigation opening setting calculator 24, the fully open or fully open position LP of the damper 14 input from the cam limit switch 1, and the opening transmitter 20. Based on the detected actual opening degree HK of the damper 14, the electric VJ machine 16 is driven via an electromagnetic opening/closing control panel 26 to accurately and reliably control the opening position of the damper 14. In addition, the first
28 in the figure indicates the opening degree of the damper 14 and the opening degree transmission +R20
This is an opening indicator that displays a failure signal from the valve. As shown in FIG. 2, the digital controller 10 internally converts the outputs of the opening transmitter 20 and the opening setting calculator 24 into analog-to-digital converters (hereinafter referred to as A/digital converters).
A/D conversion circuits 32A and 32B convert the actual opening HK signal from the opening transmitter 20 into an A/D converter.
an opening transmitter signal zero/span adjustment processing circuit 34 that calculates the actual opening value x 2 of the damper 14 based on the converted signal and the position ILP signal from the cam limit switch 18;
Then, the set opening from the opening setting section TS device 24 is determined by A/D.
After conversion, the specified opening signal averaging processing circuit 36 performs averaging processing, and the specified opening signal averaging processing circuit 36 P!
An opening indicator output processing circuit 38 outputs an output indicating the opening to an external opening indicator 28 based on the A calculation result, and a damper 14 outputs the opening transmitter signal zero/span adjustment processing circuit 34. The difference between the actual opening value x 2 and the averaged set opening D3 output from the designated opening signal averaging circuit 36 is determined, and based on the difference, the opening/closing direction and opening/closing time of the damper 14 are determined. The opening adjustment processing circuit 40 calculates and outputs the opening degree adjustment processing circuit 40. Note that, as the digital controller 10, a digital control device that controls a general-purpose sequencer, a programmable logic controller 1 to a roller, etc. by scanning processing using a stored program method can be used. The effects of the embodiment will be explained below. Digital controller D-RA 10 shown in Figures 1 and 2
processes the input signal by making full use of the scanning processing method, and the temporal processing routine is the third one.
It is as shown in the figure. Next, the processing contents of each of these four divided procedures will be explained. First, the designated opening signal averaging process in step 50 is performed in the designated opening signal averaging processing circuit 36 based on the flowchart shown in FIG. That is, as shown in FIG. 4, first, in step 110, it is determined whether the output signal from the opening degree setting calculator 24 has been sampled for the first time or ten times. When the determination result is positive, that is, when sampling is performed for the first time or 10 times, the process proceeds to step 112, where the initial reset of the sampling cycle and integrated data is performed. Next, the process proceeds to step 114, and if the determination result in step 110 is negative, the process also proceeds to step 114, in which it is determined whether the sampling clock has risen. When the determination result is positive, that is, when the sampling clock rises, the process proceeds to step 116, where the data of the set opening SK output from the opening setting calculator 24 is A/D converted according to the sampling clock. It is taken into the container 32B in batches. Based on the conversion rate shown in Figure 5, the imported data is
From the analog value corresponding to fully closed to fully open of 0IllA, the data Do of the digital value of do"dlGo corresponding to it
Convert to In this case, if a signal of 201il8 or more is input, an over signal O8 is output as an abnormality. Next, the process proceeds to step 118, where data D.1 is obtained by 1/10 of the data Do of the digitized signal.
Proceeding to step 120, averaged data D2 of the data DO is obtained based on the following equation (1). D2−Σ(Den/10) η− = (Do + +Do 2...+Do 1 o)
/10...<1) However, Don is the A/D conversion data Do taken in every sampling clock. The numbering data of the set opening degree SK is processed based on this equation (1), for example, as shown in FIG. The process then proceeds to step 122, where the sampling counter is incremented, and the process proceeds to step 124, where the sampling reaches 10.
Determine whether it has been performed twice. When the determination result is positive, that is, when sampling has been performed 10 times, the process proceeds to step 126, where the size of the averaged data D2 is determined. As shown in FIG. 7, this size determination is such that when the averaged data D2 is greater than its upper limit value Dzc, it is determined to be a full-open command, and when the averaged data 3D2 is smaller than the minimum 1i11D2 days, it is determined to be a full-open command; Furthermore, if the averaged data D2 is smaller than the abnormality 1aDz^, it is determined that one of the circuits that inputs a signal to the specified opening degree signal averaging processing circuit 36 is abnormal, and a disconnection alarm is output. The signal whose size is determined in this way and the disconnection alarm signal are sent to the opening indicator 28 via the opening indicator output circuit 38.
is output to. Next, the process proceeds to step 128, and data other than the averaged data D2 whose size has been determined as described above out of the averaged data D2 is inputted to the opening degree adjustment processing U circuit 40 as data D3 for which the averaging process has been completed. Note that when the process of step 128 is completed and the judgment results of the previous steps 114 and 124 are negative, the opening transmitter signal zero/span adjustment process of step 52 shown in FIG. Proceed to processing steps. In this way, this specified opening degree signal averaging processing circuit 36
Since the set opening SK from the opening setting calculator 24 is averaged, stability of the opening control response can be obtained. Furthermore, since the fully open and fully open positions of the damper 14 can be reliably determined, the control system can be stabilized in the vicinity of these positions. Next, the opening transmitter signal zero/span adjustment process in step 52 is performed in the opening transmitter signal zero/span adjustment circuit 34 based on the flowchart shown in FIG. In FIG. 8, first in step 130, the Ifij degree transmitter 20
The signal of the actual opening degree 1-IK of the damper 14 outputted from is converted by the A/D converter 32A based on the above-mentioned FIG. 5,
Import as digital value of damper opening data x 1. Next, in step 132, it is determined based on the signal of the position LP of the cam limit switch 18 whether the damper 14 is at the open end or not. If the judgment result is positive,
That is, when the position of the damper 14 is at the open end or the closed end, the process proceeds to step 134, where the data when the damper 14 is at the open end is fetched, and the process proceeds to step 136, where data when the damper 14 is at the closed end is acquired ×1 (take in C7. Then
In step 138, a span correction coefficient C is calculated based on the following equation (2). C= (l o o-do)/ (A-8)・”(2)
However, Δ is the data when the damper 14 is open x 1
(o) is the digital value, and B is the digital value of the data X1(c) at the r1N end of the damper 14. Next, proceed to step 140, and also proceed to step 13
If the determination result in step 2 is negative, step 140
Proceed to the above data x 1 and obtain the zero/span adjusted value x2
In order to obtain , the following equation (3) is calculated using the digital values A1B and C obtained in steps 134, 136, and 138. X2-CX (X+ 'B) ・・・・・・・・・
(3) By performing this calculation, the opening transmitter 2
The signal output from the damper 14 is reliably converted into digital values dB oo, do corresponding to when the damper 14 is fully open and when the damper 14 is fully open. is also linearly converted, and the deviation and error of the opening transmitter 20 are corrected. Furthermore, since the correction coefficients for the digital values ASB and C obtained above are updated each time the damper 14 is fully opened, zero and span adjustments are always made using the latest calculation formula. Therefore, the accuracy of this entire control system is improved. Next, the opening degree indicator output processing in step 54 is performed in the opening degree indicator output processing circuit 38 based on the flowchart shown in FIG. In FIG. 9, first step 14
2, the data of the opening degree of the damper 14 obtained by zero/span adjustment in the previous step 140 x 2 is taken in, and the process proceeds to step 144, where the data x 2 is read in accordance with the display rate of the opening indicator 28. d O""'d I U
In order to display the digital value of O' from 0 to 100%, the following formula (
Perform proportional calculation based on 4) to obtain a digital value x 3 for display. X3-XzX 100/(d+oo do)”
(4) Next, the process proceeds to step 146, where the display digital value obtained by equation (4) x 3 is displayed on the opening indicator 28, and the process proceeds to step 148, where the disconnection alarm etc. output in the previous step 126 is displayed. An abnormality alarm is displayed on the opening degree indicator 28. In this way, changes in the opening degree and abnormalities of the damper 14 are reported, thereby stabilizing the operation. Next, the opening adjustment process in step 56 is performed in the opening adjustment processing circuit 4o based on the flowchart shown in FIG. In FIG. 10, first, in step 150, it is determined based on the data D3 from the specified opening signal averaging processing circuit 36 whether the set opening to be given to the damper 14 is full open or fully open. When the judgment result is positive, that is, when the set opening degree to be given to the damper 14 is fully open or completely open, the process proceeds to step 152, and an opening/closing signal is sent to the electromagnetic opening/closing control panel 26 so that the damper 14 is fully opened or completely open. @-
On the other hand, if the judgment result is negative, step 15
4, it is determined whether there is a rising edge in the clock pulse. If the determination result is positive, the process proceeds to step 156, where it is determined whether the damper 14 has not operated since the previous clock pulse. If the judgment result is positive, the process proceeds to step 158, and in order to perform control while capturing changes in the control system at certain intervals, instead of performing constant comparison, the comparison is performed at each timing of the clock pulse that occurs at regular intervals. , average (t, data D of the set opening signal for which processing has been completed
J and the opening transmitter signal zero/span adjustment processing circuit 34
The value K of the difference from the actual opening degree signal x 2 obtained in is calculated based on the following equation (5). K=D:5-Xz ・・・・・・・・・(5
) Next, the process proceeds to step 160, in which it is determined whether the absolute value of the difference 1tlIK determined by equation (5) is larger than the deadband value Z. Note that the value of this dead band lil'l z must be set so that the corresponding operation time is longer than the inertia operation time. This is to avoid such a problem, if it is set to a small value, there is a risk that small disturbances in the control system will occur, leading to loss of control and causing a hunting operation of the damper 14. When the determination result in step 160 is positive, that is, when the absolute value of the difference value is larger than the deadband value 2, the process proceeds to step 162, and the process proceeds to step 162, where it is determined whether the difference value K is greater than zero or not. At the same time, the process proceeds to step 168 to calculate the time required for the damper 14 to open or close. If the determination result in the step 162 is positive, in a step 164, after the previous clock pulse, the damper 1
4 determines whether the closing operation has been performed. If the determination result in step 162 is negative, then in step 166 it is determined whether or not the damper 14 has opened after the forward turn O-turn pulse. This step 164
．． The processing performed at 168 is performed for a time corresponding to one clock pulse if the damper 14 operates after the previous clock pulse is generated, or for a period of time equivalent to one clock pulse after the previous clock pulse is generated, when the damper 14 operates from now on. If the operation is in the opposite direction, the damper 14 is kept on standby without opening or closing for a time corresponding to two clock pulses. As a result, if the interval or closing operation time is longer than the clock pulse interval, the damper 14 is operated continuously, and the difference value is calculated again during the clock pulse, and the damper 14 is opened. The accuracy of degree control can be improved. Further, the excessive frequency of operation of the electromagnetic switch and the electric motor 16 in the electromagnetic switching control panel 26 can be reduced, and thermal and mechanical protection can be achieved. - On the other hand, after calculating the opening/closing time of the damper 14 in the previous step 168, the process then proceeds to step 170, and step 1
A calculation is performed to subtract the inertial operation time from the time obtained in step 68. This inertial operation time is preset according to the characteristics of the damper 14 and the electric motor. Next, the process proceeds to steps 172 and '174, in which a control signal is outputted to the electromagnetic opening/closing control 26 so that the damper 14 opens, and a control signal is outputted so that the damper 14 closes. Also, if the determination result in the previous steps 164 and 166 is negative, the process proceeds to steps 172 and 174, and the opening operation signal or the closing operation signal force is outputted to the electromagnetic control illumination board 26. Note that the previous step 154.1
When the determination results in steps 56 and 160 are negative, step 164
．． When the determination result of step 166 is positive, step 152.1
After completing the processing in steps 72 and 174, the process returns to step 110 and each step is repeated again. In this way, the opening degree of the damper 14 is controlled by digital processing, and the inertial motion correction and dead band correction are performed to protect the electric motor and the electromagnetic switch.
Operational responsiveness and adjustment capability can be added. J3, the sampling clock interval and number of times in the specified opening signal averaging processing circuit 36 of the embodiment, or the full open command discrimination value (D 2 C),
Fully open command discrimination value (D2B> and the opening adjustment processing circuit 4
Interval of clock pulses at 0, motor 16
The inertial operation time, dead band value 2, etc. set according to the characteristics of the damper 14 can be easily changed. Therefore, the damper opening degree control device according to this embodiment can optimally configure a control system depending on the state in which it is used, and can respond to any control response. In the embodiment, the specified opening signal averaging processing circuit 3
6, the averaging was performed by stitching formula (1), but the circuit and calculation formula for obtaining the averaged data 3 are not limited to this, and other circuits or calculation formulas may be used.

【Effect of the invention】

As explained above, according to the present invention, even if the damper is driven by an electric motor, the opening degree of the damper can be accurately controlled λ11 without causing an error in the opening degree of the damper. Therefore, it has the excellent effect of being able to stably and precisely control the flow rate or pressure of the fluid in the pipe to be controlled by the damper.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of a damper opening control method driven by an electric motor according to the present invention, and FIG. 2 is a block diagram showing in detail the internal configuration of the digital controller of the embodiment. , FIG. 3 is a flowchart showing the main points of the control performed by the digital controller, and FIG. 4 is a flowchart showing the designated opening signal averaging process performed in the designated opening signal averaging processing circuit in the digital controller. 5 is a diagram showing the conversion rate of the A/D converter of the digital controller, and FIG. 6 is a diagram showing the data processing performed every sampling clock in the specified opening signal averaging processing circuit. A diagram showing the state, FIG. 7 is a diagram showing the state of the processing for determining the size of data performed in the specified opening signal averaging processing circuit, and FIG. FIG. 9 is a flowchart showing the opening transmitter signal zero/span adjustment process performed in the processing circuit; FIG. 9 is a flowchart showing the opening indicator output processing performed in the opening indicator output processing circuit; FIG. , is a flowchart showing the opening degree adjustment process performed within the opening degree adjustment processing circuit. DESCRIPTION OF SYMBOLS 10... Digital controller, 12... Vibrator, 14... Damper, 16... Electric motor, 18... Cam limit switch, 20... Opening degree transmitter, 22... Pressure detector, 24... Opening degree setting calculator, 26... Electromagnetic opening/closing control board, 32A, 32B... A/D converter, 34... Opening degree transmitter signal zero/span adjustment processing circuit. 36... Designated opening degree signal averaging processing circuit, 38... Opening degree display meter output processing circuit, 40... Opening degree adjustment processing circuit.

Claims (1)

[Claims] (1) Detect the pressure or flow rate of the fluid flowing in the pipe, and set the opening degree to be given to the damper installed in the pipe based on the detected value and a preset value. In the damper opening control method using an electric motor, the damper opening degree is controlled by driving the damper with an electric motor based on the obtained set opening degree, Processing is performed to cancel the change, and the difference between the detected actual opening of the damper and the set opening of the damper processed to cancel the instantaneous change is determined, and control to be applied to the damper is determined based on the difference. A method for controlling the opening degree of a damper by driving an electric motor, characterized in that the opening degree of the damper is controlled by driving the damper with the electric motor based on the control amount.