KR20060087933A - Active supply pressure control system for compressed air - Google Patents

Abstract

The present invention relates to a system for adjusting the supply flow rate of compressed air, and more particularly, to stabilize the pressure on the demand side by actively controlling the supply flow rate of the compressed air supplied from the compressor chamber according to the change in air pressure on the demand side The present invention relates to a compressed air supply pressure active servo control system.

Compressed air supply pressure active servo control system according to the present invention is installed between the outlet side of the reservoir tank located in the compressor chamber and the header line to vary the opening angle of the on-off valve provided therein according to the control signal input from the outside Flow rate adjusting means for adjusting a supply flow rate of the compressed air supplied to the header line side; A pressure sensor provided at an outlet side of the flow rate adjusting means to measure a supply pressure of compressed air supplied to a header line and output the electrical pressure as an electrical signal; In response to the difference between the pressure measurement value input from the pressure sensor and the preset pressure setting value, the pressure measurement value is input to the time change while controlling the driving of the flow rate adjusting means to adjust the supply flow rate of the compressed air supplied to the header line side. It characterized in that it comprises a controller for outputting on the screen in the form of a graph.

Supply pressure, active, PID control, flow regulator

Description

Active supply pressure control system for compressed air

1 is a schematic diagram showing the configuration of a compressed air supply system to which the compressed air supply pressure active servo control system according to the present invention is applied.

Figure 2 is a block diagram schematically showing the configuration of a controller constituting a control system according to a preferred embodiment of the present invention.

3 is a circuit diagram for explaining a conversion process of a PWM signal output from a microcomputer.

4 is a diagram illustrating an output screen of the control system according to the present invention.

<Explanation of symbols for the main parts of the drawings>

100: flow control means

300: compression sensor

500: controller

510: control panel

520: LCD display unit

530: micom

531: timer section, 532: memory section,

533: analog / digital conversion unit, 534: flow control unit

555: screen generation unit

540: signal conversion unit

541: filter portion, 542: linear current amplifier portion

550 screen control unit

560: amplification unit

570: communication interface unit

The present invention relates to a system for adjusting the supply flow rate of compressed air, and more particularly, to stabilize the pressure on the demand side by actively controlling the supply flow rate of the compressed air supplied from the compressor chamber according to the change in air pressure on the demand side The present invention relates to a compressed air supply pressure active servo control system.

In order to advance the industrial structure, improve competitiveness and productivity, each industry is accelerating the automation of production facilities, and the automation trend using pneumatic pressure has been increasing rapidly since the early 80s.

Industrial robots are the main element of production equipment automation. As most industrial robots use pneumatics as the main energy source to simplify the apparatus, various pneumatic devices including pneumatic compressors are widely used throughout the industry.

Therefore, electricity and pneumatic are basically recognized as basic energy sources for production automation. Pneumatic systems are used as main energy sources for various production equipment because they have better safety and higher energy density per unit volume than electric equipment.

 However, most pneumatic systems operate without systematic consideration of energy efficiency, which causes serious power waste. Reported in foreign cases, only 50% of the compressed air produced is used for production, while 25-30% by leaks, 10-15% by pressure loss, and 5-10 by misuse / pneumatic pressure. A loss of% is occurring.

In addition, in order to prevent a decrease in productivity due to severe fluctuations in the supply air pressure, power consumption is maintained by keeping the supply air pressure at the maximum, which is a serious energy waste factor.

That is, the actual compressed air supply system is a situation in which severe pressure fluctuations occur for various reasons.

As a representative reason, the capacity of the reservoir tank is selected as small as compared to the capacity of the air compressor, and the compressor is frequently loaded / unloaded, which may cause serious fluctuations in the supply of compressed air. Pressure loss occurs.

Extreme pressure loss can also be caused by improper capacity selection of valves, filters and piping materials. Since compressed air is supplied at the maximum pressure in order to prevent a sudden drop in the supply air pressure caused by the sudden change in the demand for pneumatic pressure, the loss of pressure causes severe energy waste.

In addition, despite the need to use regulators to minimize the demand for pneumatics at the end-use stages, it is necessary to operate the machine at excessively high pressures to avoid product defects due to unstable fluctuations in pneumatics. The situation is causing a decrease.

The present invention has been invented to solve the above problems, the compressed air supply pressure to stabilize the pressure on the demand side by actively controlling the supply flow rate of the compressed air supplied from the compressor chamber in accordance with the change in air pressure on the demand side The purpose is to provide an active servo control system.

In particular, it aims to provide a compressed air supply pressure active servo control system that can monitor the supply pressure change in real time.

It is also an object of the present invention to provide a compressed air supply pressure active servo control system that can more precisely control the flow rate of supply pressure by minimizing the error of demand side supply pressure measured by the pressure sensor according to the electrical environment at the site installation.

In addition, it is an object of the present invention to provide a compressed air supply pressure active servo control system that can suppress the hunting phenomenon occurs in accordance with the opening and closing of the valve.

In addition, it is an object of the present invention to provide a compressed air supply pressure active servo control system that can monitor the operating state of the pneumatic system at a remote location without restriction of distance through communication.

Active air control pressure supply system according to a preferred embodiment of the present invention for achieving the above object is installed between the outlet side and the header line of the reservoir tank located in the compressor chamber according to the control signal input from the outside Flow control means for controlling the supply flow rate of the compressed air supplied to the header line side by varying the opening angle of the on-off valve provided therein, and supply of compressed air provided to the header line side provided on the outlet side of the flow control means A pressure sensor for measuring a pressure and outputting the electrical signal; and driving the flow rate adjusting means to adjust a supply flow rate of compressed air supplied to the header line according to a difference between a pressure measurement value input from the pressure sensor and a preset pressure set value. The pressure measurement input at the same time That a controller for the output to the screen in graphic form according to features.

According to this configuration, the compressed air supply pressure active servo control system according to the present invention adjusts the opening angle of the on / off valve of the flow regulating means according to the difference between the pressure measurement value and the pressure setting value on the demand side measured by the pressure sensor and the header line. By actively stabilizing the pressure on the header line side according to the pressure change on the side, it is possible to produce compressed air at the minimum pressure and flow rate required by the stabilization of the supply air pressure, thereby reducing the power cost of producing compressed air.

In particular, the pressure measurement on the header line side, which is the demand side measured by the pressure sensor, is output on the screen in the form of a graph over time, so that the manager can easily check the operating state of the device and the change in supply pressure.

The invention will become more apparent through the preferred embodiments described below with reference to the accompanying drawings. Hereinafter will be described in detail to enable those skilled in the art to easily understand and reproduce through these embodiments.

1 is a schematic diagram showing the configuration of a compressed air supply system to which a compressed air supply pressure active servo control system according to the present invention is applied.

As shown in the drawing, a compressed air supply system of a large plant to which an active servo control system for compressed air supply pressure according to the present invention is applied is to supply high-quality compressed air necessary for a pneumatic automation device or a plant facility, and an air compressor, A rear cooler, an air dryer, a reservoir tank, a flow rate adjusting means having a pressure sensor on the outlet side, a header line, and the like.

According to this configuration, the compressed air supply system supplies compressed air supplied from the compressor chamber by the flow rate adjusting means of the compressed air supply pressure active servo control system according to the present invention installed between the reservoir tank outlet side and the demand line header line. The flow rate is actively adjusted according to the change in air pressure on the demand side to stabilize the supply pressure of the compressed air supplied to the demand side.

That is, the compressed air supply pressure active servo control system according to the present invention has an opening / closing provided in the flow control means 100 installed between the reservoir tank outlet side and the demand line header line according to a signal input from the controller 500. By varying the opening angle of the valve, the supply flow rate of the compressed air supplied to the demand side is varied to stabilize the supply pressure on the demand side.

In addition, the controller 500 of the compressed air supply pressure active servo control system according to the present invention is the pressure on the header line side, which is a demand side measured by the pressure sensor 300 according to an operation signal input from the operation unit 510 provided on the front surface. By outputting the measured value to the LCD display unit 520 in the form of a graph over time, the administrator can easily check the operating state of the device and the change of the supply pressure.

Therefore, the compressed air supply system to which the compressed air supply pressure active servo control system according to the present invention is applied is opened and closed according to the difference between the pressure on the demand side and the set pressure measured by the pressure sensor installed at the outlet side of the flow regulating means. By adjusting the opening angle of the valve, the pressure on the header line side can be actively stabilized in accordance with the change in the demand pressure on the header line side, thereby producing compressed air at the minimum pressure and flow rate required for stabilizing the supply air pressure. Can reduce the power cost.

Hereinafter, the configuration of the compressed air supply pressure active servo control system according to the present invention will be described in detail.

As shown in FIG. 1, the compressed air supply pressure active servo control system according to the present invention includes a flow rate adjusting means 100 for adjusting a flow rate of compressed air supplied from a reservoir tank side to a demand line in response to an external signal; The pressure sensor 300 for measuring the pressure of the compressed air supplied to the header line and the control of the flow control means 300 according to the measurement value input from the pressure sensor 300 and the measured pressure measurement graph over time It includes a controller 500 for controlling to display in the form.

The flow rate adjusting means 100 is installed in a connection pipe connecting between the outlet side of the reservoir tank and the header line, and supplies compressed air supplied from the outlet side of the reservoir tank to the header line side according to a control signal input from the controller 500. Adjust the flow rate.

That is, in the embodiment of the present invention, the flow rate adjusting means 100 is composed of a valve positioner and a butterfly valve which is an open / close valve, and adopts a valve positioner manufactured by Posle flate of USA.

The valve positioner is equipped with a pneumatic actuator. The permanent magnet is used to adjust the opening and closing angle of the butterfly valve installed in the connecting pipe by adjusting the pneumatic actuator output by adjusting the control signal as the set value and the position of the drive shaft as the measured value. As a force balance positioner using a motor or a torque motor using a coil, a detailed description thereof will be omitted since it is already known before the filing date.

Therefore, the flow rate adjusting means 100 configured as described above operates the valve positioner according to the control signal input from the controller 500 to generate the driving air pressure of the pneumatic actuator. The generated air pressure causes the actuator mounted on the valve positioner to rotate.

Accordingly, the butterfly valve installed inside the connecting pipe is opened and closed at a predetermined angle in accordance with the rotational force of the actuator. Therefore, the supply flow rate of the compressed air supplied to the demand side is adjusted so that the supply pressure on the demand side can be adjusted.

For example, if the air pressure drops with increasing pneumatic demand, the opening angle of the butterfly valve increases. On the contrary, when the air pressure rises as the pneumatic demand decreases, it reduces the opening angle of the butterfly valve to regulate the air pressure on the demand side, which reduces the flow rate through the connecting pipe.

As such, the signal for controlling the driving of the flow regulating means is output from the controller, and the description thereof will be described in more detail in the controller to be described later.

In addition, the pressure sensor 300 is provided on the outlet side of the flow rate adjusting means 100 to measure the supply pressure of the compressed air supplied to the header line side, that is, the supply pressure of the compressed air consumed on the demand side, and output it as an electric signal.

In the embodiment of the present invention, the pressure sensor 300 is a capacitive semiconductor sensor among semiconductor sensors, which has no hysteresis phenomenon, excellent linearity, and is small and lightweight, and is also very strong against vibration. The semiconductor pressure sensor includes a diaphragm for converting external pressure into a stress and a converter for converting power generated from the diaphragm into an electrical signal to output a voltage signal, which is an electrical signal proportional to the pressure. Since the technology is a detailed description thereof will be omitted.

Meanwhile, according to a characteristic aspect of the present invention, the controller 500 controls the driving of the flow regulating means through a PIC microcomputer-based PID control algorithm. That is, the controller 500 controls the driving of the flow rate adjusting means 100 to adjust the supply flow rate of the compressed air supplied to the header line side according to the difference between the pressure measurement value input from the pressure sensor 300 and the preset pressure setting value. In addition, the controller 500 controls to output the pressure measurement input from the pressure sensor 300 in real time on the screen in the form of a graph according to time changes.

That is, the controller 500 according to the present invention includes an operation unit 510 for receiving a manager's operation signal as shown in FIG. 2, an LCD display unit 520, a microcomputer 530 for controlling driving of the entire apparatus, and A signal converter 540 for converting the control signal input from the microcomputer 530 into an electrical signal, and a screen controller 550 for controlling the screen signal output from the microcomputer 530 to be output to the LCD display unit 520. do. The controller 500 further includes an amplifier 560 and a communication interface 570.

The operation unit 510 receives a manager's operation signal, and various keys are installed under the LCD display unit 520 installed in the front of the controller. In the embodiment of the present invention, the operation unit 520 is a menu for setting various types of menus output through the LCD display unit 520, for example, a pressure setting menu for setting a supply pressure required on the demand side or a time setting for time setting. ? And? Keys for selecting a measured pressure zero adjustment menu and the like for compensating for the pressure measurement according to the menu and the surrounding environment, and a selection key for selecting a menu moved by an arrow key operation.

On the other hand, the microcomputer 530 calculates the actual pressure value for the pressure measurement value input from the pressure sensor 300 according to the operation signal input from the operation unit 510 and outputs the calculated actual pressure measurement value as a screen signal according to time change. In addition, the microcomputer 530 simultaneously controls the driving of the apparatus to output a control signal for controlling the driving of the flow regulating means 100 according to the difference between the actual pressure measurement value and the preset pressure setting value.

In the embodiment of the present invention, the microcomputer 530 is hardware-decrypted by the RISC method. That is, since the circuit in the chip is designed to decode all instructions in hardware, the processing speed of the instructions is significantly faster than that of the CISC method. The timer unit 531, the memory unit 532, and the analog / digital The converter 533 includes a data corrector 534, a flow rate control controller 535, and a screen generator 536.

The memory unit 532 includes a flash memory, an EEPROM, and an SRAM. The memory unit 532 stores pressure set values input from various programs and control units for controlling driving of the apparatus as a whole, pressure measured values input from a pressure sensor, and pressure correction values.

Here, the pressure set value means a target pressure value of the compressed air used for the pneumatic automation device or the plant facility. In addition, the pressure correction value means a noise value generated by the electric environment of the site during the site installation. In other words, the pressure correction value is a pressure value for correcting a phenomenon in which a difference between the pressure measurement measured by the pressure sensor and the pressure measurement recognized by the controller due to the electric environment around the site is indicated. In the embodiment of the present invention, the above-described target input value and pressure correction value are set according to the operation of the manager.

The analog / digital converter 533 converts an electrical signal, which is an analog signal input from the pressure sensor 300, into a digital signal. That is, the amount of analog voltage input from the pressure sensor 300 is converted into an 8-bit digital value. Accordingly, the controller converts an electrical signal input from the pressure sensor through an analog / digital converter into a signal that can be processed by the microcomputer.

In addition, according to an additional embodiment of the present invention, since the input signal input from the pressure sensor 300 is very weak, the controller 500 may provide an input signal between the pressure sensor 300 and the microcomputer, that is, the analog / digital converter 533. An amplifying unit 560 for amplifying the predetermined size is further provided.

Accordingly, the controller 500 prevents distortion of the weak signal of the pressure sensor input to the analog / digital converter 533 through the amplifier 560 and amplifies and outputs an input of a very small input signal. In addition, the amplifying unit 560 loads the output, the output current flows to supply power, but the current hardly flows to the input so that the output does not affect the input. That is, in this embodiment, the amplifier 560 has a high input impedance and low output impedance, and thus acts as a kind of buffer amplifier to prevent the load effect of the driving circuit.

The pressure measurement converted into the digital signal is corrected to the actual measurement of the supply pressure of the current demand side through the data correction unit.

The data correction unit 534 calculates an actual pressure measurement value for the pressure measurement value input from the analog / digital converter 533 using the pressure correction value stored in the memory unit 532.

The pressure measurement input to the controller of the system according to the present invention includes the noise component due to the electrical environment around the system when the system is installed on site. Accordingly, the pressure correction value corresponding to the noise component is corrected to the pressure measurement value input from the pressure sensor through the data correction unit 534.

That is, when the system is installed in the field, the data correction unit 534 measures the pressure measured from the pressure sensor and the actual pressure value for the actual demand-side supply pressure, respectively, by the electric environment around the site. The pressure measurement inputted through the pressure sensor by the difference is calibrated and calculated.

Therefore, the microcomputer of the controller according to the present invention can not only accurately measure the supply pressure of the compressed air that is currently required through the data correction unit, but also operate the flow control means more accurately through the flow control unit. .

On the other hand, the flow rate control unit 535 outputs a control signal for controlling the driving of the flow rate control unit according to the difference between the actual pressure measurement value output from the data correction unit 534 and the pressure set value stored in the memory unit 532.

That is, in the embodiment of the present invention, the flow rate control controller 535 is a proportional calculus controller and generates a differential signal according to the difference between the actual pressure measurement value and the pressure set value. In addition, a control signal corresponding to the differential signal is generated through the proportional calculus control scheme, and the pulse width is modulated to output a signal in the range of 1V to 5V to the signal converter 540.

At this time, the maximum closing control signal of the flow regulating control unit to close the closing valve included in the flow regulating means of the output signal output to the signal conversion unit 540 is the maximum closing angle of the switching valve included in the flow regulating means It is desirable to restrict to maintain a predetermined angle.

Accordingly, by limiting the closing angle of the butterfly valve of the flow regulating means to 90% by the maximum closing control signal output from the flow regulating control unit, it is possible to suppress the occurrence of hunting phenomenon caused by the closing of the butterfly valve completely do.

That is, when the butterfly valve is completely closed by the control signal output from the flow control controller, the supply pressure on the header line side, which is the demand side, drops sharply, and the valve opens rapidly to make up for it. However, by limiting the maximum closed control signal itself output from the flow rate control unit as described above, a certain angle is always open, so that the occurrence of the hunting phenomenon can be suppressed. In this way, the occurrence of the hunting phenomenon can be suppressed in hardware. For example, a rotational bump may be used inside the connection pipe to limit the rotation angle of the butterfly valve.

Therefore, the microcomputer according to the present invention can stably control the supply pressure within the pressure fluctuation range by controlling the supply pressure for the compressed air according to the difference between the actual pressure measurement value and the pressure set value through a proportional calculus control scheme.

In particular, the maximum closing angle of the on / off valve included in the flow regulating means is opened while maintaining a predetermined angle by the maximum closing control signal of the flow regulating control part which causes the on / off valve included in the flow regulating means to close to the maximum. It is possible to suppress the occurrence.

On the other hand, the screen generating unit 536 outputs an output screen output to the LCD display unit 520, for example, a text and graph screen for the pressure set value set by the manager's operation and the supply pressure measurement value of the demand side measured by the pressure sensor. Generates a screen signal to output.

According to a characteristic aspect of the present invention, the screen generating unit 536 may output the actual pressure measurement value output from the data correction unit 534, the time information input from the timer unit 531, and the pressure setting value stored in the memory unit 532. Generates a screen signal to output to the screen in the form of a graph according to the time change with reference to.

In particular, the screen generating unit 536 displays the pressure set value stored in the memory unit 532 in a dotted line, and outputs a screen signal to display the actual pressure measurement output from the data correction unit 534 in a solid line.

Therefore, the microcomputer constituting the controller according to the present invention according to the configuration as described above through the proportional calculus control scheme to control the control signal for supplying pressure to the compressed air corresponding to the differential signal according to the difference between the actual pressure measurement value and the pressure set value By generating and pulse-modulating the pulse width and output-controlling the signal converter, the supply pressure can be stably controlled within the pressure fluctuation range.

In addition, the microcomputer outputs a screen signal that implements a real-time pressure change graph of the actual pressure measured by the pressure sensor through the screen generator, thereby monitoring the change in supply pressure. In particular, when the set pressure is changed on the LCD display, a dotted line appears at the set pressure position, and the actual measured pressure is displayed by the solid line, thereby enabling easy monitoring of the pressure control situation and the pressure deviation.

Meanwhile, the signal converter 540 converts a pulse width modulation (PWM) signal, which is a control signal output from the microcomputer, into an electrical signal and outputs the electrical signal to the flow rate adjusting means 100. The filter unit 541 and the linear current amplifier unit ( 542).

The filter unit 541 converts the pulse width modulation signal output from the flow rate control unit 535 of the microcomputer into a smoothing circuit to a voltage signal having a predetermined level. The linear current amplifier 542 converts the voltage signal output from the filter unit 541 into a current signal.

That is, the pulse width modulated signal output from the flow rate control unit 535 of the microcomputer is smoothed and applied to the non-inverting end of the OP-Amp through the resistor and the capacitor of the signal converter as shown in FIG. 3. In the OP-Amp characteristic, the output voltage makes the voltage difference between the two inputs zero, so as much voltage as input by the PWM is applied to the source of the FET.

In addition, the voltage-current characteristics of the FET appear in a form in which the output current is adjusted by the input voltage, so that an external bias voltage is appropriately applied to the three terminals of the gate, drain, and source, and thus the flow of current, which is an electrical signal output to the flow adjusting means. To control.

Therefore, the controller according to the present invention controls the current output of 4 ~ 20 mA required to drive the valve positioner of the flow rate control means by the PWM signal of 1V ~ 5V output from the flow rate control control unit to drive the valve positioner To control.

The screen controller 550 controls to display the screen signal output from the microcomputer 530 on the LCD display. That is, in the embodiment of the present invention, the screen controller 550 is a graphic Hangul LCD display module and is equipped with functions necessary for driving the LCD display unit. For example, a screen that is output from a microcomputer with a built-in font ROM containing Korean, English, numbers, and special characters as well as graphic functions such as dots, lines, circles, boxes, etc. Control to display the signal on the LCD display.

Since the graphic Hangul LCD display module is a known technology before the filing date of the present application, a detailed description of the configuration and various functions of the module will be omitted.

Therefore, the screen controller 550 controls to display the LCD on the LCD display unit 520 according to the screen signal output from the screen generator 536 of the microcomputer. That is, as shown in FIG. 4, the screen controller 550 may be configured to a pressure set value set by a manager's operation on a text layer and an actual supply pressure measurement value of a demand side measured by a pressure sensor according to a screen signal input from the screen generator. Print textual information about A graphic screen of pressure variation is displayed on the graphic layer.

In particular, the set pressure on the LCD display part is indicated by a dotted line at the set pressure position according to the control signal of the screen generating part, and the actual measured pressure is displayed by the solid line. It can be easily monitored.

In addition, according to an additional embodiment of the present invention, the controller 500 further includes a communication interface 570 that outputs the actual pressure measurement output from the data corrector 534 to the outside.

In this embodiment, the communication interface unit 570 is an RS232C communication interface unit. By connecting a Bluetooth module or a TCP / IP connection module supporting near field communication to the interface unit, the supply pressure measured in the field via wired / wireless It is possible to see the operating status of the data on the office monitor.

Hereinafter, an operating state of the compressed air supply pressure active servo control system according to the present invention having the configuration as described above will be described with reference to FIGS. 1 to 3.

First, when the pressure measurement value for the demand pressure on the header line side, which is the demand side, is input from the pressure sensor 300 installed at the outlet side of the flow regulating means 100, the input pressure measurement value is converted into an analog / digital converter 533. Is converted into digital data. The actual pressure measurement value of the demand side is calculated through the data correction unit 534.

The flow control unit 535 of the microcomputer constituting the controller outputs a drive signal of the flow control unit corresponding to the difference between the pressure set value stored in the memory unit and the actual pressure measurement value input from the data correction unit 534.

At this time, the control signal generated by the flow rate control unit 535 is generated by the PID control method as described above and converted into an electrical signal necessary for driving the valve positioner of the flow rate control unit through a signal conversion unit with a pulse width modulated signal. Output to the valve positioner.

Accordingly, the flow rate adjusting means 100 generates a driving air pressure of the pneumatic actuator by operating the valve positioner according to the electric signal input from the controller 500. The generated air pressure causes the actuator mounted on the valve positioner to rotate. Accordingly, the butterfly valve installed inside the connection pipe is opened and closed at a predetermined angle according to the rotational force of the actuator to adjust the supply flow rate of the compressed air supplied to the header line, which is the demand side.

On the other hand, the microcomputer 530 of the controller controls the actual pressure measurement value input from the data compensator 534 to output the screen signal displayed on the LCD display unit 520 through the screen generator 536.

That is, the screen generator 536 converts the measured pressure value into a hexadecimal coordinate system on the LCD display by using a programming technique with respect to the actual measured pressure output from the data compensator 534 as described above. The hexadecimal coordinate system, which is converted to implement real-time monitoring function using the time information input from the timer unit 531, is again converted into hexadecimal coordinates for a change in time, and the current pressure state is once every 15 seconds. A screen signal is generated to be displayed and output to the screen controller 550.

Accordingly, the controller displays text information and a real-time fluctuation pressure graph on the LCD display according to the screen signal input from the screen generator through the screen controller.

As described in detail above, the compressed air supply pressure active servo control system according to the present invention adjusts the opening angle of the on / off valve of the flow regulating means according to the difference between the pressure on the demand side and the set pressure measured by the pressure sensor. By actively stabilizing the pressure on the header line side according to the pressure change on the line side, it is possible to produce compressed air at the minimum pressure and flow rate required by the stabilization of the supply air pressure, thereby reducing the power cost of producing compressed air. .

In particular, the pressure measurement on the header line side, which is the demand side measured by the pressure sensor, is output on the screen in the form of a graph over time, so that the manager can easily check the operating state of the device and the change in supply pressure.

In addition, by calculating the actual pressure measurement of the measured pressure through the data correction unit, it is possible to adjust the flow rate of the supply pressure more accurately by minimizing the error of the demand-side supply pressure measured by the pressure sensor in accordance with the electrical environment in the field installation .

In addition, by limiting the closing angle of the butterfly valve of the flow regulating means by 90% by the maximum closing control signal output from the flow regulating control unit, it is possible to suppress the occurrence of the hunting phenomenon caused by the butterfly valve is completely closed.

By connecting a Bluetooth module or a TCP / IP connection module that supports short-range communication through the communication interface, it is possible to more conveniently grasp the operation state on the office monitor of the supply pressure data measured in the field via wired or wireless. .

Although the present invention has been described with reference to the accompanying drawings, it will be apparent to those skilled in the art that many different and obvious modifications are possible without departing from the scope of the invention from this description. Therefore, the scope of the invention should be construed by the claims described to include many such variations.

Claims (8)

It is installed between the outlet side of the reservoir tank located in the compressor chamber and the header line to adjust the flow rate of the compressed air supplied to the header line by varying the opening angle of the on / off valve provided therein according to a control signal input from the outside. Flow rate adjusting means; A pressure sensor provided at an outlet side of the flow rate adjusting means to measure a supply pressure of compressed air supplied to a header line and output the electrical pressure as an electrical signal; In response to the difference between the pressure measurement value input from the pressure sensor and the preset pressure setting value, the pressure measurement value is input to the time change while controlling the driving of the flow rate adjusting means to adjust the supply flow rate of the compressed air supplied to the header line side. A controller outputting the screen in the form of a graph; Compressed air supply pressure active servo control system comprising a. The method of claim 1, wherein the controller is: LCD display unit, An operation unit which receives an operation signal of a manager, The actual pressure value for the pressure measurement value input from the pressure sensor is calculated according to the operation signal input from the operation unit, and the calculated actual pressure value is output on the screen in the form of a graph according to time change, and at the same time as the difference from the preset pressure setting value And a microcomputer for controlling driving of the entire apparatus to output a control signal for controlling driving of the flow rate adjusting means. A signal converter converting the control signal output from the microcomputer into an electrical signal and outputting the electrical signal to the flow rate adjusting means; And a screen controller for controlling the screen signal output from the microcomputer to the LCD display unit. The method of claim 2, wherein the microcomputer is: With timer part, A memory unit storing pressure set values and pressure correction values and various programs inputted from the operation unit; An analog / digital converter for converting an analog signal input from the pressure sensor into a digital signal; A data correction unit for correcting and calculating an actual pressure measurement value with respect to the pressure measurement value input from the analog / digital conversion unit using the pressure correction value stored in the memory unit; The signal is converted by generating a differential signal according to a difference between the actual pressure measurement value output from the data correction unit and the pressure set value stored in the memory unit, and pulse width modulating a control signal corresponding to the differential signal through a proportional calculus control scheme. A flow rate control unit for outputting Screen generation for generating a screen signal to output the actual pressure measurement output from the data correction unit to the screen in the form of a graph according to the time change with reference to the time information input from the timer unit and the pressure set value stored in the memory unit Compressed air supply pressure active servo control system comprising a. The method of claim 3, wherein The maximum closing control signal output from the flow rate control unit so that the on-off valve of the flow rate adjusting means closes to the maximum, the maximum closing angle of the on / off valve included in the flow rate adjusting means maintains a predetermined angle. Compressed air supply pressure active servo control system. The method of claim 3, wherein And the screen generating unit displays the pressure set value stored in the memory unit in a dotted line, and displays the actual pressure measurement value input from the data correcting unit in a solid line. The method of claim 3, wherein the signal conversion unit: A filter unit for converting the pulse width modulation signal output from the flow rate control unit into a voltage signal having a predetermined level; Compressed air supply pressure active servo control system comprising a linear current amplifier for converting the voltage signal output from the filter unit into a current signal. The method of claim 3, wherein the controller is: And an amplifier for amplifying a signal input from the pressure sensor and outputting the amplified signal to the analog / digital converter. The method of claim 3, wherein the controller is: Compressed air supply pressure active servo control system further comprises a communication interface for outputting the actual pressure measurement output from the data correction unit to the outside.

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