CN100388144C - Intelligent two-wire system electropneumatic valve positioner and control method therefor - Google Patents
Intelligent two-wire system electropneumatic valve positioner and control method therefor Download PDFInfo
- Publication number
- CN100388144C CN100388144C CNB2005100162651A CN200510016265A CN100388144C CN 100388144 C CN100388144 C CN 100388144C CN B2005100162651 A CNB2005100162651 A CN B2005100162651A CN 200510016265 A CN200510016265 A CN 200510016265A CN 100388144 C CN100388144 C CN 100388144C
- Authority
- CN
- China
- Prior art keywords
- control
- intelligent
- unit
- current
- valve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The present invention relates to an intelligent two-line electric valve positioner which comprises a control circuit unit, an I/P electric converting unit and a valve position test feedback unit, wherein input signals and feedback signals of the valve position enter into a microprocessor control unit of the intelligent electric valve positioner control circuit together to carry out a comparison operation. According to deviations of the input signals and the feedback signals of the valve position, the present invention outputs one control signal to the I/P electric converting unit to control the output atmospheric pressure of the I/P electric converting unit and the valve rod the mileage of driving charging section of the highway of a pneumatic governor valve, the travel of the valve rod is simultaneously fed back to the control circuit unit to form closed-loop control. The present invention takes the microprocessor as a control core, adopts the electric balance principle instead of the traditional force equilibrium principle to achieve accurate control of the valve position by converting electric control instructions to pneumatic positioning gains, and strengthens and expands functions of the positioner. The whole machine is controlled by a singlechip to realize full digitization and intelligence, and thoroughly alters traditional situation that field requirements are met by means of processing of parts with different structures and site adjustment.
Description
Technical field
The present invention relates to electric variable valve steady arm, particularly relate to a kind of intelligent electric controlled atmosphere joint valve positioner system and control method thereof.
Background technology
Along with progress of industry, the steady arm of electric control valve from initial be the steady arm of principle of work with pure pneumatic, mechanical force balance, develop into afterwards be the electricity/pneumatic valve positioner of principle of work with the electromagnetic conversion, up to the intelligent of today with use the steady arm of field bus technique.Its total trend is electrification, intellectualized operation and control, and will adapt with totally digitilized Industry Control.
At present, the steady arm that China uses mainly is based on the mechanical type steady arm of force balance principle, it adopts nozzle-baffle technology, this steady arm is in use easy to wear, when being installed, adjustment need regulate a series of spring screws usually repeatedly to reach dynamic balance, operating process very complicated, control underaction, the valve that can not cooperate different stroke forms easily, and precision can not guarantee.
After pneumatic positioner valve, electropneumatic valve positioner has also appearred in this area, and the direct current setting signal of 0～10mA or 4～20mA is adopted in its input.This class locator structure and above-mentioned pneumatic positioner valve are similar, and difference only is that corrugated tube has changed electromagnet into, and it is output as air pressure signal, can realize the double action of pneumatic positioner valve and electropneumatic transducer.Because the input of electropneumatic valve positioner is a current signal, and what need in the side circuit is a different set of voltage, need the voltage of 3.3V as the MCU power supply, and the control piezoelectric ceramic valve needs 24V or higher voltage, therefore must be through certain conversion and processing.Power-switching circuit in the electropneumatic valve positioner, its task are exactly that the electrorheological of input is changed into 3.3V and two groups of power supplys of 24V, use for microcontroller and other devices.In the state of the art, the realization of power-switching circuit is earlier input current to be converted into a lower voltage, produce vibration by oscillator again, obtain the required voltage value by rectification, filtering and linear voltage stabilization at last, but the shortcoming of this scheme is that the key component of circuit (transformer) needs own coiling.And, make the precision of its this series products be difficult to guarantee just because of the technological process restriction that is subjected to the coiling transformer, poor, the job insecurity of the consistance of operating result, and power consumption is bigger, and volume is also very huge.
Summary of the invention
The present invention is just in order to solve the defective that above-mentioned prior art exists, and a kind of intelligent two-wire system electropneumatic valve positioner and control method thereof are proposed, piezo technology is applied to steady arm, adopt high integration power supply design proposal, and can utilize high integrated microprocessor to realize the control of pneumatic Direct Travel of intelligent two-wire system electropneumatic valve positioner or angle stroke actuators.
The invention provides a kind of intelligent two-wire system electropneumatic valve positioner, comprise control circuit unit, I/P electric conversion unit and valve position detection feedback unit, described control circuit unit comprises power-switching circuit and microprocessor control unit, described I/P electric conversion unit comprises gas circuit control and the amplifier section that is made of two piezo electric valve groups, and described valve position detection feedback unit comprises feedback potentiometer and valve position feedback lever; The microprocessor control unit that input signal and valve position feedback signal together enter described intelligent electric valve positioner control circuit compares computing, export a control signal to I/P electric conversion unit according to both deviations, the output pressure of control I/P electric conversion unit and the stem movement of pneumatic control valve, the stroke of valve rod feeds back to control circuit unit simultaneously, form closed-loop control, it is characterized in that described power-switching circuit is the power-switching circuit that the input current signal of 4～20mA is converted to 6V, 3V and three groups of voltages of 24V.
The present invention also provides a kind of intelligent two-wire system electropneumatic valve positioner control method, utilize microprocessor to interrupt and liquid crystal display operation in control circuit unit by data acquisition, button, realization is carried out switching between each pattern by button, carry out corresponding action and control strategy, parameter shows, it is characterized in that this method may further comprise the steps:
1) shutdown system house dog clock generator stops regularly, and opens global interrupt;
2) port initialization;
3) call the liquid crystal display subroutine, the display operation result;
4) carry out the A/D channel selecting, clock, timing setting, and open the A/D interruption;
5) be provided with the button clock, timing is set, open button and interrupt;
6) enter low-power consumption mode of the present invention;
7) judge currently whether arrive the A/D interrupt timing time;
Arrive as the A/D interrupt timing, then enter the A/D interruption subroutine;
Carry out the A/D interruption subroutine;
Interruption is returned, and waits for and satisfies timing next time;
Otherwise, judge whether the current time has arrived the button interrupt timing;
As this moment the button interrupt timing arrive, then enter the button interruption subroutine;
Carry out the button interruption subroutine, interrupt returning, wait for that timing arrives next time.
Compared with prior art, the speed regulating method that the present invention proposes based on the asynchronous motor of motion electromotive force control, the intelligent electric pneumatic valve positioner is core with the microprocessor, adopt electrobalance (digital balance) principle to replace traditional force balance principle, by automatically controlled instruction transformation being become pneumatic location increment realize accurate control, strengthen and expanded the function of steady arm to valve position.Complete machine adopts Single-chip Controlling, realized total digitalization, intelligent, as the discharge characteristic correction, automatic zero set (AZS) can be realized by software function with transferring range, warning, fault self-diagnosis, on-the-spot demonstration etc., these characteristics are that existing similar project is not available, have thoroughly changed different part processing of traditional dependence structure and the on-the-spot situation that adapts to field requirement of adjusting.
Be elaborated below in conjunction with embodiment and with reference to the technical scheme of accompanying drawing to this invention.
Description of drawings
Fig. 1 is the functional module structure figure of intelligent two-wire system electropneumatic steady arm of the present invention;
Fig. 2 is the main flow chart of intelligent two-wire system electropneumatic steady arm control method of the present invention;
Fig. 3 is the A/D conversion interrupt routine process flow diagram of intelligent two-wire system electropneumatic steady arm control method of the present invention;
Fig. 4 is the keyboard interrupt handling procedure process flow diagram of intelligent two-wire system electropneumatic steady arm control method of the present invention.
Fig. 5 is the liquid crystal display handling procedure process flow diagram of intelligent two-wire system electropneumatic steady arm control method of the present invention;
Fig. 6 is the power converting circuit figure in the Intelligent Electro-Pneumatic Valve Positioner control circuit of the present invention;
Fig. 7 is the high-side current detection circuit figure of the power converting circuit in the intelligent two-wire system electropneumatic steady arm of the present invention;
Fig. 8 is the switched capacitor voltage inverter circuit of the power converting circuit in the intelligent two-wire system electropneumatic steady arm of the present invention;
Fig. 9 is the inductive type switching mode DC-DC converter circuit figure of the power converting circuit in the intelligent two-wire system electropneumatic steady arm of the present invention;
Figure 10 is the excess voltage protection figure of the power converting circuit in the intelligent two-wire system electropneumatic steady arm of the present invention;
Figure 11 is a Single-chip Controlling unit hardware block scheme of the present invention;
Figure 12 is for Liquid Crystal Module of the present invention adopted based on I
2The Application of Interface block scheme of C bus;
Figure 13 is the control circuit figure of the I/P electrical equipment converting unit of intelligent two-wire system electropneumatic steady arm of the present invention.
Embodiment
Generally, for the two-wire system steady arm, its input current signal scope is 4～20mA, and this signal provides the needed energy for steady arm simultaneously as positioning signal.The total current drain of system must require (promptly guarantee under the condition of minimum current 4mA circuit still can operate as normal) less than the minimum current in loop.In order to leave certain allowance, simultaneously for the intelligent transducer of compatibility based on the HART agreement, then design entire circuit the maximum consumption electric current on be limited to 3.5mA.Just because of the harsh requirement of two-wire system system to power consumption, so the design and optimization of control circuit is the key that technical solution of the present invention realizes, overall design of the present invention is promptly around how realizing that low-power consumption launches.
Intelligent two-wire system electropneumatic valve positioner proposed by the invention is made up of Intelligent Electro-Pneumatic Valve Positioner control circuit unit 101, electric (electric current/air pressure) converting unit of I/P and valve position detection feedback unit, and its system architecture as shown in Figure 1.Come the input signal and the valve position feedback signal of self tuning regulator together to enter microprocessor, compare computing, export a control signal to the I/P converting unit according to both deviations, the output pressure of control I/P unit and the stem movement of pneumatic control valve, the stroke of valve rod feeds back to control module simultaneously, forms closed-loop control.
Wherein, control circuit unit is the PCB printed circuit-board assembly, mainly comprises:
1, DC/DC power-switching circuit is used for converting the input current signal of 4～20mA to 6V, 3V and three groups of voltages of 24V.Specifically, three groups of voltages are respectively: a. produces the 6V power supply with linear power supply; B. produce the 3V power supply with charge pump; C. produce the 24V power supply with inductive type switching mode DC-DC transducer; Also comprise sample circuit in this power-switching circuit.
2, control module
Adopt the super low power consuming single chip processor application system, the MSP430 single-chip microcomputer of TI company for example mainly comprises:
The a.A/D modular converter; B. human-machine interface module; C. pulsed drive module; D. Design of System Software.
Above-mentioned control circuit unit is the PCB printed circuit-board assembly, and it leaves 4 splicing ears at erecting frame, and the electric conversion I/P unit below printed panel is connected, and leaves the screw connecting terminal box simultaneously and is connected with the valve position feedback system; Valve position detection feedback unit does not have the gap with regulating valve rod and cooperates by rigidly connected connecting rod.
Gas circuit control and amplifier section that I/P electric conversion unit is made of two piezo electric valve groups, the pneumatic valve group is installed in enclosure interior, and the pneumatic interface of air inlet and output pressure is positioned at a side of steady arm, is connected with the PCB printed circuit board (PCB).
Valve position detection feedback unit comprises feedback potentiometer and valve position feedback lever, it is by rigidly connected connecting rod, do not have the gap with regulating valve rod and cooperate, thereby the stroke of variable valve (displacement or corner) is converted to the corner of feedback potentiometer, and then can be converted into electric signal.It is not conventional potentiometer that parameter setting adopts potentiometer, the potentiometer that is used to feed back, but a kind of special potentiometer that ball bearing and durable resistive foil are housed.Resistive foil is made with special wear-resistant conductive plastics material.Therefore potentiometer can be used for various occasions, and part can not damage yet continuously.
Operation valve A and B are used for controlling pressurized air turnover pneumatic control valve, and valve A is a gas admittance valve, and valve B is a vent valve, and these two valves all have only " opening " and " pass " two states.This control thought is actually with little valve controls compressed air require, promotes big valve with pressurized air again, controls the flow of controlled medium, is a kind of design proposal of step control.
Specifically, at any one time, can only have among valve A, the B one open-minded, another is closed.If when A opens, owing to compressed air pressure greater than film head internal pressure, so pressurized air enters variable valve, valve rod moves down; If otherwise when B opens, the indoor pressurized air of modulating gas valve is arranged people's atmosphere through B, and valve rod moves up under the effect of spring, in intelligent valve positioner, for can with the control circuit interface, opening and turn-offing of valve A and B must be able to be controlled by power consumption.The valve A, the B that use in the reality have polytypes such as solenoid valve, piezoelectric ceramic valve.Used herein is a kind of piezoelectric ceramics operation valve, and its ultimate principle is the piezoelectric effect according to piezoelectric.With the piezoelectric ceramic piece of a small pieces special facture, add that in its both sides 24～30V voltage piezoelectric ceramic piece will bend, total deformation quantity can reach tens microns.Thereby can block/decontrol air intake opening or exhausr port, reach the purpose of control air-flow.Because the impedance of piezoelectric ceramics is very high,, be easy to realize two-wire system instrument and explosion-proof so that the advantage of this operation valve is a power consumption is extremely low.In addition, its quick action, light weight, thereby still can reliably working in the bigger environment of vibrations.
As shown in Figure 2, be the main program flow of intelligent two-wire system electropneumatic valve positioner control method proposed by the invention, mainly constitute by data acquisition subroutine, button interruption subroutine, liquid crystal display subroutine etc.Realization shows the control and the result of the fixture system that the present invention proposes.In major cycle, carry out switching between each pattern by button, carry out corresponding action and control strategy, show the parameters such as parameter, valve opening of input.This master routine may further comprise the steps: at first, shutdown system house dog clock generator stops regularly, and opens global interrupt, step 201; The initialization port, step 202; Call the liquid crystal display subroutine, display operation result, step 203; Carry out the A/D channel selecting, clock, timing setting, and open A/D interruption, step 204; The button clock is set, timing is set, open button and interrupt step 205; Enter low-power consumption mode of the present invention, step 206; Judge current A/D interrupt timing time, the step 207 of whether arriving; Arrive as the A/D interrupt timing, then enter the A/D interruption subroutine, step 208; After executing the A/D interruption subroutine, interrupt returning, wait for and satisfy timing next time; Otherwise current A/D interrupt timing does not arrive, and then continues to judge whether the current time has arrived button interrupt timing, step 209; As this moment the button interrupt timing arrive, then enter the button interruption subroutine, step 210; After executing the button interruption subroutine, interrupt returning, wait for and satisfy timing next time.
What can realize in above-mentioned master routine is: steady arm can be determined zero point, range, action direction and the locating speed of actuator automatically according to input parameter when initialization.During work, can change, revise controlled variable, aging, the wearing and tearing equal error of compensation valve automatically according to the mechanical property of valve or actuator.Realized total digitalization, intelligent, as the discharge characteristic correction, automatic zero set (AZS) can be realized by software function with transferring range, warning, fault self-diagnosis, on-the-spot demonstration etc., these characteristics are that existing similar project is not available, have thoroughly changed different part processing of traditional dependence structure and the on-the-spot situation that adapts to field requirement of adjusting.
As shown in Figure 3, flow process for the A/D interrupt handling routine 30 of intelligent two-wire system electropneumatic valve positioner control method proposed by the invention, it is the subroutine of being called by master routine under the situation of satisfying condition, this subroutine comprises following steps: at first, carry out the input signal sampling, step 301; Judge whether current be to adopt P6.4 sampling channel, step 302; In this way, then preserve the A/D transformation result of current sampling, step 303; Judge and finished 5 samplings, step 304; In this way, then carry out digital filtering and handle step 305; The result carries out linearization process, step 306 to digital filtering output; Output signal result is provided with an AD1, step 307; As not, then further judge the whether P6.5 sampling channel of current employing, step 308; If do not satisfy 5 samplings, then return step 301, continue to finish signal sampling;
If current sampling channel is not P6.4, then continue to judge whether current sampling channel is P6.5, step 308; If then preserve the A/D transformation result of current sampled result, step 309; Judge whether to finish 5 samplings, step 310; In this way, then carry out digital filtering, step 311; And linearization process, step 312; And this output signal result is set to AD2; In like manner,, then return step 301, continue to finish sampling if sampling number does not satisfy 5 times.
As shown in Figure 4, button interrupt handling routine for intelligent two-wire system electropneumatic valve positioner control method proposed by the invention, this also is a subroutine of being called in by main program flow under the situation of satisfying condition, it may further comprise the steps: enter button interrupt handling routine 40, judge the current button push that whether receives; Step 401; By the button recognition function, obtain the key assignments of the current button of pressing, step 402; Judge whether to press step 403 for mode key; As not, then backspace subroutine begins, and waits for the reception of new actuation of keys again; In this way, judge further then whether the time that current button is pressed surpasses 5 seconds, step 404; In this way, then be set at configuration mode, step 405; According to the ongoing operation time of user, select different mode of operations respectively: i.e. configuration mode, manual mode and automatic mode to button; Step 405 is to step 409.The function of button depends on selectable mode of operation:
1, automatic mode automatically changes by setting value and constantly makes the deviation of system be tending towards minimum value as far as possible through the steady arm of initialization (and configuration).At this moment+1 key and-1 key are inoperative;
2, manual mode makes steady arm switch to manual mode from automatic mode by the mode of operation key.By reach substep adjustment by+1 key or-1 key.In order to reach quick lift-rising, earlier by+1 key, and then by-1 key; In like manner, for reaching quick decline, earlier by-1 key, again by+1 key.In case release+1/-1 key, topworks just is parked in its current position.Interior setting value is adjusted to current performance variable.Because the manual mode inner control is closed loop,, still can keep current valve position even when therefore being in steady arm source of the gas leakage accident;
3, configuration mode can be converted to configuration mode from automatic mode or manual mode with the mode of operation button, for this reason, must pin at least 5 seconds of mode switch key, until finishing conversion.
Wherein, configuration parameters mainly comprises: the type of execution architecture (angle stroke or Direct Travel), feedback angle (30 ° and 90 °), stroke value, auto-initiation, manually initialization, input current scope, positive retroaction, valve confinement function.
Under configuration mode, can change the parameter value of steady arm, use mode key can select next parameter, if by mode key (＜pin-1 key in 5s), then with reversed sequence selection parameter.Utilize+1 button or-1 button can change parameter value.
As shown in Figure 5, be liquid crystal display subroutine flow process of the present invention, by master routine is called, it may further comprise the steps: write the initialization command defining mode, step 501; Define inner RC mode of oscillation, step 502; Start oscillator, step 503; Open display, step 504; Write data time sequence, step 505 continuously; Show the valve position program, step 506; Show the configuration mode program, step 507.
The present invention has adopted Liquid Crystal Module LCM046, and it has less size, and power consumption is very low, powerful, so, during system design, do not utilize the built-in liquid crystal driver module of MSP430 single-chip microcomputer, and adopt based on I
2The connected mode of C bus,
Below by specific embodiment, further specify the implementation of the system of intelligent two-wire system electropneumatic valve positioner of the present invention.
(1) steady arm control circuit unit
DC-DC transducer commonly used at present mainly contains linear voltage regulator, inductive type switching mode DC-DC transducer and capacitance charge pump DC-DC transducer.In three kinds of power supply changeover devices, linear voltage regulator is simple, ripple-free and electromagnetic interference emission (EMI), but efficient is low and output voltage can only be lower than input voltage; Switch power efficiency height, the most flexible, can provide boost, step-down and opposite polarity output, be voltage ratio V
Out/ V
InHigh ideal is selected, and guarantees that the key of low ripple, EMI and noise is circuit design; Charge pump can provide equally and boost, step-down, opposite polarity output, and efficient is higher, and external circuits is simple, low EMI and low ripple, but its output current is limited.
Because power module needs to convert input current to multi-group power, so comprehensive three's characteristics, the power supply design proposal that adopts three's mode to combine is used to produce the supply voltage of different amplitudes.The present invention proposes the power supply of novel two-wire system system, its power-switching circuit figure as shown in Figure 6.In this power-switching circuit, comprise polarity protection and the anti-interference part of power supply front end, produce 6V power supply, high-side current detection circuit, produce 3V power supply, inductive type switching mode DC-DC transducer realization 24V power supply, 2.5V voltage reference with the switching capacity voltage inverter with linear power supply; The overvoltage protection unit.
1. polarity protection and the anti-interference part of power supply front end;
Square 1:JP1 is an input terminal, and 3 is the anode of 4～20mA, and the output of 1 and 2 ends elder generation short circuit is connected to the output terminal of electric current loop.3 are connected with U0 (schottky diode), are the polarity protection effect.U0 and inductance L 11,1 end of JP1 links to each other with inductance L 12, and they link to each other with U1 respectively more then, and U1 is a common mode choke, and this connected mode is in order to eliminate the high-frequency crosstalk of common mode interference and power supply front end.R1, C1 are in series and U1 joins, and prevent the appearance in a certain frequency range resonance effect.Circuit is input as 4～20mA electric current loop, because misoperation or fortuitous event can will damage switching power supply with its polarity wrong.The purpose of polarity protection is exactly only to work as with correct polarity to connect, and power supply could be worked.Utilize the device of unidirectional conducting to realize, adopt the polarity protection of the schottky diode of low pressure reduction here as circuit.
2, produce the 6V power supply with linear power supply
Sample resistance Rsense is connected on the back segment of square 1, the other end links to each other with U2, U2 is the Zener diode of 6V, the one end links to each other with sample resistance Rsense, the other end inserts ground level, C2, C3 are respectively tantalum electrochemical capacitor and little ceramic condenser, and C2, C3 are in parallel with U2, in order to eliminate low frequency and high frequency interference.
The 6V power supply that the anode of U2 is power circuit provides end, can find out that by square 2 circuit is simple and reliable.
Because power circuit is to be connected in 4～20mA electric current loop, so adopt shunt regulating circuit comparatively desirable.Zener diode, buried Zener diode and energy gap voltage reference all can be designed to parallel circuit in two ends or three end tandem circuit for three kinds.Zener diode needs the current-limiting resistance of a series connection for being operated in back-biased diode.Under the situation that requires high precision and low-power consumption, Zener diode is normally unaccommodated, but Zener diode is usually used in voltage clamping circuit, its clamping voltage scope is very wide, and from 2V to 200V, power can be from several milliwatts to several watts, and it sucks the very capable of electric current, low price.So, utilize the effectively characteristic of clamping voltage, ABSORPTION CURRENT of Zener diode, produce the 6V power supply and absorb unnecessary electric current simultaneously.Adopt simultaneously the schottky diode of low pressure reduction as the polarity protection of circuit (during tens mA electric currents, forward voltage drop＜0.3V).
3, the design of sample circuit
Valve positioner requires single-chip microcomputer can receive the current signal (4～20mA) of the by-pass valve control aperture of self tuning regulator, for this reason, at the front end of the power circuit sample resistance of connecting, amplify by differential amplifier at the sample resistance two ends, sends into microprocessor and sample.Float influence to The measuring precision in order to reduce temperature, current sense resistor selects for use Heat stability is good, the little constantan wire of drift to make.
Based on the requirement of power consumption, need select single supply op for use, will reduce range of signal.Therefore, the choice of location of sample resistance is particularly important.The author designs two kinds of different sampling modes according to the difference of sample resistance position.Sampling mode one: high-side current detects
The input common-mode range of high-side current detecting amplifier is independent of operating voltage, even can guarantee that like this current detection circuit is still effective under the situation of low-work voltage.Its circuit connects situation as shown in Figure 7.This circuit is just taken from the partial enlarged drawing of square 3 among Fig. 6.Wherein, U3 is the high-side current detecting amplifier, and 1 end is a power end, and 6V terminal direct and square 2 joins, and C4 is a shunt capacitance, links to each other with 1 end, 3 ends respectively.8 ends, 6 ends access the two ends of sample resistance R sense respectively.4 ends are output voltage terminal, and R2, C5 form filtering circuit and link to each other with 4 ends, then the filtering voltage value are sent into the AD1 of microprocessor.
The present invention selects the max4372 of Maxim company for use, and it is a kind of flash current sense amplifier with buffering output.Max4372 has following characteristics: wide power voltage range: 2.7V～28V; Circuit structure allows 0V to 28V to import; Supply voltage independently; When the common mode voltage of input closely during voltage, ground connection is detected input end and is kept good linearty and stop the output phase reversing.In addition, current sinking only is 30 μ A during amplifier work, reaches 0.18% full scale accurate rate, the output impedance of 1.5 Ω.Saved the voltage output that Zeng Yi Let puts.
The high-side current detecting amplifier of Maxim adopts a resistance that is connected in power positive end and circuit under test power import to detect electric current, and high-side current detects and avoided introducing external resistance to ground level, has improved the overall performance of circuit and has simplified wiring.
4, produce the 3V power supply with the switching capacity voltage inverter
Charge pump is also referred to as the switching capacity voltage changer, and the loss of charge pump is mainly from the ESR and the transistorized conducting resistance of internal switch (RDSON) of capacitor, and the two can do very lowly.The benefit that adopts the charge pump maximum is to eliminate the magnetic interference that is caused by inductance or transformer, and the pump input noise can be eliminated by filter capacitor, and circuit design is simply effective, only needs external ceramic condenser.
We utilize the paraphase characteristics of " voltage is relative quantity " this thought and switching capacity during design, design stable 3V power supply cleverly, and its circuit connecting relation as shown in Figure 8.It is the local amplifying circuit of the square 4 in the corresponding diagram 6.With output terminal 1 end ground connection, it is output terminal that 4 ends are held on ground, and input end 2 ends are the 6V voltage end, and like this, ground end output is actual to be 0.5 times of input end, i.e. the 3V power supply.
Because max1720 has the characteristics of high-level efficiency, High Output Current, so this partial circuit power consumption is extremely low and because the Switching Power Supply decompression transformation can promote output current, the Power supply belt load capacity strengthens greatly.
That we select for use is the switched capacitor voltage inverter max1720 of Maxim company, it adopts the SOT23-6 encapsulation, can carry out paraphase or multiplication of voltage to the input voltage in 1.5V～5.5V scope, voltage transitions efficient is 99.9%, the quiescent current of 50 μ A (using when turn-offing pin lower), output current can reach 25mA.
5, inductive type switching mode DC-DC transducer is realized the 24V power supply
Owing to need to provide the power supply of 24V among the design, and Switching Power Supply is voltage ratio V
Out/ V
IoHigh ideal is selected, so select for use inductive type switching mode DC-DC transducer to realize the 24V power supply.
The principle of work of inductive type DC-DC transducer is first storage power, releases energy in a controlled manner then, thereby obtains needed output voltage.Common minimum needs external inductors, electric capacity and a schottky diode, that select for use here is max1605, this chip operating voltage is+2.4V is to+5.5V, can rise to 28V with hanging down the cell voltage that reaches 0.8V, its working current only is 18 μ A, conversion efficiency is 88%, helps reducing the ripple and the outer member size of output voltage in little electric current is used, and its circuit connection situation is seen shown in Figure 9.It is the local amplifying circuit of the square 5 among Fig. 6.1, the 2 end short circuits of U5 are connected with the 3V power supply.C7 is a shunt capacitance, a termination power, other end ground connection.5 ends and 3 end short circuits insert ground level.Inductance L 3 one ends link to each other with the 6V of process holding circuit, and the other end is connected with D1 with 4 ends.6 ends are the feedback input, and its threshold value is 1.25V.
The inductive type boost converter is that low-voltage-drop linear voltage regulator (LDO) can't replace, although the voltage stabilizing charge pump can be realized boosting, efficient is lower, and output current is less.The shortcoming of boost converter is that output ripple and switch noise are bigger.The controlling schemes that need choose reduces the loss in efficiency that the switched field effect pipe causes with oscillation-damped, takes following solution for this reason:
(1) selection of energy storage inductor: inductance is the Primary Component that influences the DC-DC converter performance, and the main parameter of considering has inductance value, saturation current and direct current resistance.We select the power inductance that direct current resistance is lower, saturation current is bigger for use, and this inductance is generally the coil that is wrapped on the FERRITE CORE.When the electric current of the inductance of flowing through is big, add the saturated of magnetic core, actual inductance value will be descended, so should select the inductance of big (crossing the peak point current of inductance greater than actual flow) of saturation current for use, in general, 20% slightly saturated (inductance value descends 20%) is acceptable.
Inductance value generally can be selected between 10 μ H to 300 μ H.Too small inductance value will make inductive current discontinuous, causes the electric current fan-out capability to reduce, and output ripple increases, and might be before current limliting comparer switch-off power switch, makes inductive current be increased to very big value and causes the damage of DC-DC converter; Inductance value is excessive then can to cause the instant response variation, and increases DC-DC converter volume.Choosing of inductance value should be foundation with actual input/output condition and to the requirement of output ripple, transient response etc.
I/O condition among the design is:
Input voltage V
Fn=3V;
Output voltage V
Out=26V;
Output current I
Out=20mA;
Maximum operation frequency F
Max=500kHz;
The peak delta I=0.5A of inductive current pulsation during output-current rating.
The calculation procedure of inductance peak point current is as follows:
1. computed duty cycle: D=(V
Out-V
In)/V
Out=88.5%;
2. calculate average inductor current: I
Lavb=I
Out/ (1-D)=0.173A;
3. calculate inductance peak point current: I
LP=I
Lavb+ Δ I/2=0.423A;
4. calculate inductance value: L ≈ V
In* D/ (Δ I*F
Max)=10.6 μ H.
Then can choose saturation current and be not less than 0.173A, the inductance about inductance value 11 μ H.
(2) selection of sustained diode
For improving conversion efficiency, this device should be selected the lower schottky diode of forward conduction voltage drop for use.Its major parameter is inverse peak voltage V
RAnd maximum forward current value I
D, we select the MBRS0530 of Motorola for use here.
(3) selection of ripple electric capacity
The equivalent series resistance ESR of filter capacitor is the principal element that causes output ripple, and can have influence on conversion efficiency.Ceramic condenser and tantalum electrochemical capacitor have lower ESR, also can select the alminium electrolytic condenser of low ESR for use, but should avoid the standard aluminum electrochemical capacitor as far as possible, and capacity is generally got 10 μ F～100 μ F, for heavier load, should choose bigger electric capacity.The filter capacitor of larger capacity helps improving output ripple and transient response.Here, select little ceramic condenser for use, ceramic condenser can obtain low input and output noise, and reliable operation under high-temperature condition takies less area simultaneously again.
(4) eliminate the DC-DC noise
The universal method of eliminating the DC-DC noise is inhibition technology, particularly filtering and shielding.Another solution of saving cost is that the frequency of operation (noise source) with the DC-DC transducer locks onto clock frequency, the ripple of this frequency and radiation do not influence system performance, noise spectrum can be removed simultaneously, improve system performance and save cost (need not shielding).
62.5V voltage reference
1 end of U6 is a power end, links to each other with 6V power supply and 5 ends, and 2,4 ends are held with being, directly connects.1, insert C11 between access capacitor C 10,3 ends and 2 ends between 2 ends, C10, C11 are tantalum electric capacity, and the appearance value is at 1～10uf, and 3 ends are output terminal, output reference voltage 2.5V.
7, overvoltage protection
When Zener diode punctures or normally during voltage stabilizing; to make the switching regulator cisco unity malfunction; even damage internal components; therefore; be necessary to use the input excess voltage protection; automatically shut down the step-up/step-down circuit of Switching Power Supply, its circuit connection situation is seen shown in Figure 10, promptly corresponding to the local amplification circuit diagram of the square among Fig. 67.
U7 is the charge pump amplifier, when comparer is used.2 ends of U7 (operational amplifier negative terminal) connect 2.5 benchmark, and the partial pressure value of 3 (operational amplifier anode) termination 6V power supply is under the normal operating conditions, 3 terminal voltages are lower than 2 end group standards, the output terminal 6 end output low levels of U7, not conducting of field effect transistor U8, then each power circuit keeps duty.When Zener diode normally during voltage stabilizing, 3 terminal voltages are higher than 2 ends, 6 ends output high level, and field effect transistor U8 conducting, then the other end voltage clamp of R8 automatically shuts down the ascending, descending volt circuit of Switching Power Supply in zero potential.
8, the PCB of Switching Power Supply design
The layout of printed board cabling mode and components and parts usually can influence the performance of circuit, so when the design and printing wiring board, need contemplate the placement problem of cabling mode and components and parts.Otherwise the efficient of printed-wiring board (PWB), maximum output current, output ripple and other characteristic all will be affected.Two main causes that produce these influences then are being connected of ground wire (GND, VSS) and power lead (VCC, VDD).If ground wire and power lead are reasonable in design, circuit can normally be worked, and obtain the preferable performance index, otherwise can produce problems such as interference, performance index deterioration.
The several problems that note in below proposing to design:
A. use plane routing mode (planar pattern) ground connection and connect power lead, guarantee the ground wire low noise and avoid many long wire jumpers to cut apart ground plane;
B. place components and parts in regular turn one by one by the trend of the marking current in the circuit diagram, guarantee that the line between them is the shortest,, simultaneously components and parts are placed on same direction, be convenient to reflow soldering to reduce noise;
C. owing to producing stray capacitance between connecting up, long line can produce impedance, so notice that in design stray capacitance helps eliminating noise with the shortening length of arrangement wire between line, reduces the generation of radiation;
D. carry out the layout of element according to circuit theory diagrams, input current line and output current line should be distinguished;
E. adopted coil and transformer in the ifs circuit, must carefully connect;
F. must guarantee the gap more than 0.5 millimeter between components and parts or between components and parts pad and pad, avoid occurring bridge joint.
In boost converter, note also following some:
A. output capacitance is close with IC as far as possible, reduce current return as far as possible;
B. carry out ground wire at the back side of pcb board with the plane routing method and connect, the ground wire of backboard face links to each other with the ground wire in plate front by a via hole;
C. guarantee that feedback resistance and feedback pin are short as much as possible and as far as possible little at feedback pin place wiring area;
D. electric capacity is in parallel uses to reduce the equivalent series resistance in parallel (ESR) of filter capacitor, also makes each electric capacity can shunt a part of ripple current simultaneously.
For the power consumption of further reduction system, at first to shorten working hours as far as possible, prolong the power down time; Next is to cooperate external circuit to reduce the power consumption of system, will carry out some settings before promptly entering power-down mode:
A closes power supply that does not use peripheral components etc.;
B. counterpart is handled: to the I/O mouth that uses as accurate bidirectional interface, if a mouthful line has external pull-up resistor, then should put height before entering power-down mode, close inner pull-down transistor; If a mouthful line does not connect external pull-up resistor (adopt on the inside and draw), then enter and should put before the power-down mode lowly, pull up transistor to close inside; Split and should put height before a mouth line of Lou exporting configuration enters power-down mode, these operations should at first guarantee the external function of mouth certainly;
C. turn off some obsolete function, as the detection of power loss analog comparator etc., watchdog function is more special, configuration in the time of can only programming, in the program in case use and just it can not be turned off.Not needing watchdog function not enable its function when programming gets final product.
Wherein, localization part and operating part constitute a backfeed loop, and input block accepts 4～20mA current signal of self-controller.The throttle position feedback signal compares in microprocessor as controlled variable and given signal value, its deviation is sent the pulse of different length by the delivery outlet of master control borad, generation puts on the output pressure of control I/P converting unit, drives the variable valve action thereby finish.
(2) single-chip computer control system
Control module is selected the MSP430F149 super low power consuming single chip processor that has FLASH for use, and its FLASH storer reaches 60KB, and RAM reaches 2KB; 12 A/D converters have internal reference source, sampling maintenance and autoscan characteristic; The clock source can make device reach minimum power consumption flexibly; Numerically controlled oscillator (DCO) can make device wake up rapidly from low-power consumption mode, activates in the time that is less than 6 μ s.Its hardware principle block diagram as shown in figure 11.The realization of native system MSP430 Single Chip Microcomputer (SCM) system low-power consumption is with discontinuity work even most of situation system to be under free time or the power-down mode.In the Single Chip Microcomputer (SCM) system of being interrupted work, the quiescent dissipation of peripheral components is first-selected index.The MSP430 series monolithic is integrated in a large amount of CPU peripheral modules in the sheet and each module of system is independent operating fully, timer (Timer), I/O port (I/O Port), A/D conversion, house dog (Watchdog), LCD (LCD) etc. can be under the state of host CPU dormancy independent operating.Any one module can be waken CPU up by interruption when the needs host CPU is worked, thereby system is moved with lowest power consumption.This function can be so that the power consumption of SCM peripheral system reduces greatly.MSP430F149 has the Flash storer of 60KB, system configuration parameter can be write, thereby reduce the current drain that external EEPROM brings.
1, LCD display module
Because the LCD power consumption is lower and can reach preferable man-machine conversation effect, so select for use it as display device.LCD and button provide Man Machine Interface together, and display is used to show the various status informations of valve positioner, and button is used to import configuration data and manual operation.
LCD MODULE is selected 48 sections LCD MODULE LCM046 for use, it includes house dog (WDT) clock generator, the buzzing driving circuit of 2 kinds of frequencies, built-in display random access memory, can show the arbitrary fields stroke, 3-4 line serial line interface, can with any single-chip microcomputer, IC interface, low-power consumption characteristic, show state 40 μ A (representative value), battery saving mode＜1 μ A, operating voltage 2.4～5.2V, the visual angle contrast is adjustable, clear display, reliable and stable, use programming simple, be the best universal display module of instrument and meter, hand-portable instrument etc.
Liquid Crystal Module LCM046 has less size, and power consumption is very low, powerful, thus during The Hardware Design, do not utilize the built-in liquid crystal driver module of MSP430 single-chip microcomputer, and adopt based on I
2The connected mode of C bus, its Application of Interface block scheme as shown in figure 12, thereby can save the I/O port greatly, the expansion of microprocessor after being convenient to.Because there is pull-up resistor LCM046 inside, be to guarantee low-power consumption, send after the number at every turn ,/CS ,/RD ,/WR, DATA must connect high level or suspension.Here the operating voltage of MCU and LCM046 is identical, can directly join./ RD ,/IRQ, BZ can, get final product with three-wire interface :/CS ,/WR and DATA.
2, I/P control circuit
Because piezoelectric ceramics needs the above driven of 24V, and the pulse height of microprocessor output can only reach its power supply amplitude, is not enough to drive piezoelectric ceramic valve.So need extra I/P control circuit, pulse by a small margin (3V) be transformed into significantly (more than the 24V) pulse.
Because isolated gate FET is a field effect of utilizing semiconductor surface, how much change the conducting channel Control current by induced charge, its grid is in non-conductive (insulation) state, characteristics such as general transistor volume is little, weight is low so it not only has concurrently, power consumptive province, life-span length, and also have input impedance very high (up to 10
15Ω), low, the Heat stability is good of noise, advantage such as capability of resistance to radiation is strong and manufacturing process is simple, thereby expanded its range of application widely.
The circuit of I/P converting unit is to utilize the on-off action of the reinforced insulation gate field-effect transistor (MOSFET) of N raceway groove to control.So-called enhancement mode is meant U
GS=0 o'clock, there is not conductive channel between the drain-source, even between drain-source, add voltage (within the specific limits), there is not drain current yet, its control circuit is as shown in figure 13.In this control circuit, the way of output of utilizing timer A0, A1, B0, the B1 of MSP430 single-chip microcomputer to produce different amplitudes is controlled four terminals of piezoelectric ceramics.Lifting one of them unit is example, when P1.0 output high level, and then Q1 pipe conducting, the Q2 grid voltage is 0V, then the Q2 pipe ends, piezoelectric ceramics 1 end output this moment 0V; When the P1.0 output low level, the Q1 pipe ends, and Q2 manages conducting, piezoelectric ceramics 1 end output 24V.By the output waveform of control timer A0, and then the different conditions that the control piezo electric valve continues to open, intermittently open or valve position is constant.The principle of other three unit is identical, repeats no more.
3, Design of System Software
One of software design task of low-power dissipation system is exactly to cooperate hardware circuit, further reduces the power consumption of system.System software adopts modular design, and not only program structure is clear, and is convenient to further expand.System software is made of modules such as master routine, timer interrupt service routine, keyboard interrupt service routine, data acquisition process subroutine, liquid crystal display subroutine, power down protection subroutines.
Advance people's dormant state after the master routine initialization, close each peripheral power supply.Each function program is waken CPU up by the timer timer-triggered scheduler, carries out the conversion of analog quantity and other processing.Dispose and enter dormant state again.Interrupt service routine is the core of this Design of System Software, and in order to reduce power consumption, main subroutine module is all finished in interrupt service routine.
(1) master routine
The MSP430 single-chip microcomputer has development environment very easily, can use C or C Plus Plus, improves the efficient of exploitation debugging work greatly; Simultaneously, the document information that is produced is also understood easily, is convenient to transplant.And for the single-chip microcomputer of FLASH type, then have and develop debugging enironment very easily, because the JTAG debugging interface is arranged in the device sheet, also has the erasable FLASH storer of writing, so can adopt in the FLASH that downloads, the operation by software control procedure in device is then read the sheet internal information by jtag interface and is debugged exploitation for the deviser and use.This mode only needs a PC and a JTAG debugger, and does not need emulator and programmable device.
The MSP430 single-chip microcomputer has a kind of activity pattern and 5 kinds of low-power consumption modes, and its mode of operation is by the control bit setting.Under various mode of operations, the active state of 3 kinds of clocks that clock system produces and the power consumption of system have nothing in common with each other.
Utilize the low power mode of operation of MSP430 single-chip microcomputer, behind the microcontroller electrification reset, system at first carries out initialization operation, as the setting of interrupting, the distribution of port etc., enters dormant state then.Close each peripheral power supply.Each function program is waken CPU up by the timer timer-triggered scheduler, carries out the conversion of analog quantity and other processing.Disposing enters dormant state again,
Referring to Fig. 2, master routine mainly is made of data acquisition subroutine, button interruption subroutine, liquid crystal display subroutine etc.In major cycle, carry out switching between each pattern by button, carry out corresponding action and control strategy, show the parameters such as parameter, valve opening of input.
For the power consumption of further reduction system, at first to shorten working hours as far as possible, prolong the power down time; Next is to cooperate external circuit to reduce the power consumption of system, will carry out some settings before promptly entering power-down mode:
A closes power supply that does not use peripheral components etc.;
B. counterpart is handled: to the I/O mouth that uses as accurate bidirectional interface, if a mouthful line has external pull-up resistor, then should put height before entering power-down mode, close inner pull-down transistor; If a mouthful line does not connect external pull-up resistor (adopt on the inside and draw), then enter and should put before the power-down mode lowly, pull up transistor to close inside; Split and should put height before a mouth line of Lou exporting configuration enters power-down mode, these operations should at first guarantee the external function of mouth certainly;
C. turn off some obsolete function, as the detection of power loss analog comparator etc., watchdog function is more special, configuration in the time of can only programming, in the program in case use and just it can not be turned off.Not needing watchdog function not enable its function when programming gets final product.
(2) data acquisition interrupt service routine
This module is mainly finished the ADC sampled data is handled and closed-loop control, and the setting signal and the feedback signal of valve position is converted to digital quantity, the error of calculation.In power down moment, protect useful information and system running state automatically, can recover duty before the power down during incoming call automatically, guarantee the continuity handled, its process flow diagram is as shown in Figure 3.
Main operation is all finished in timer, can make the work of single-chip microcomputer discontinuous manner, with abundant reduction power consumption; When not working, make it be in low-power consumption mode 3.The analog to digital conversion part is finished in timer A1; The Piezoelectric Driving module is then utilized timer A0 and B0 to be operated in comparison pattern and is produced needed signal, to satisfy the requirement of system to low-power consumption.
In the control of valve position, native system adopts the five-point switch control algolithm.So-called five-point switch, be meant error range divide honest, center, dead band, negative in, negative big five zones, in zones of different, carry out different actions and reduce error: when error during in honest or negative big zone, controller output continuous signal is given the piezoelectricity operation valve, continue air inlet or exhaust, stroke is changed fast; Zone in hitting exactly or bearing, the pulse signal of output certain width, interrupted air inlet or exhaust, stroke slowly changes; In the dead band, output signal not, stroke does not change.
In order to reduce interference to sampled value, improve the reliability of system, usually adopt the method for digital filtering.Medium filtering is that several sampled values are arranged in certain sequence, and as arranging from small to large, getting its intermediate value then is this sampled value.This method is applicable to variable change process more slowly, eliminates the interference that accidentalia causes; And the arithmetic mean value filtering is the addition of continuous sampling value several times summation, and divided by sampling number n, the gained result is as this time sampled value.This method is applicable to the sampled signal that recurrent pulses change.The digital composite filtering that native system adopts arithmetic mean value filtering and medium filtering to combine not only can be eliminated the recurrent pulses interference but also can eliminate random pulses and disturb.
(3) button interrupt service routine
This program circuit is referring to Fig. 4, and button is provided with three buttons of units shared (+1 key ,-1 key and mode of operation button) and is used the setting of the pattern of finishing the work, manually operated control valve position, the setting of controlled variable etc.Equally, in order to reduce power consumption, the design adopts the mode of interruption to handle key response, carries out the switching between each pattern, and the function that reaches any configuration button depends on selectable mode of operation:
1. automatic mode
Automatic mode is pattern commonly used, automatically changes by setting value and constantly makes the deviation of system be tending towards minimum value as far as possible through the steady arm of initialization (and configuration).At this moment+1 key and-1 key are inoperative.
2. manual mode
By the mode of operation key, make steady arm switch to manual mode from automatic mode.By reach substep adjustment by+1 key or-1 key.In order to reach quick lift-rising, earlier by+1 key, and then by-1 key; In like manner, for reaching quick decline, earlier by-1 key, again by+1 key.In case release+1/-1 key, topworks just is parked in its current position.Interior setting value is adjusted to current performance variable.Because the manual mode inner control is closed loop,, still can keep current valve position even when therefore being in steady arm source of the gas leakage accident.
3. configuration mode
Can be converted to configuration mode from automatic mode or manual mode with the mode of operation button, for this reason, must pin at least 5 seconds of mode switch key, until finishing conversion.
Configuration parameters mainly comprises:
A. the type of execution architecture (angle stroke or Direct Travel)
B. feed back angle (30 ° and 90 °)
C. stroke value
D. auto-initiation
E. manually initialization
F. input current scope
G. positive retroaction
H. valve confinement function
Under configuration mode, can change the parameter value of steady arm, use mode key can select next parameter, if by mode key (＜pin-1 key in 5s), then with reversed sequence selection parameter.Utilize+1 button or-1 button can change parameter value.
(4) liquid crystal display program
Liquid Crystal Module LCM046 has less size, and power consumption is very low, powerful, so, during system design, do not utilize the built-in liquid crystal driver module of MSP430 single-chip microcomputer, and adopt based on I
2The connected mode of C bus, its process flow diagram as shown in Figure 5.
Claims (9)
1. intelligent two-wire system electropneumatic valve positioner, comprise control circuit unit, I/P electric conversion unit and valve position detection feedback unit, described control circuit unit comprises power-switching circuit and microprocessor control unit, described I/P electric conversion unit comprises gas circuit control and the amplifier section that is made of two piezo electric valve groups, and described valve position detection feedback unit comprises feedback potentiometer and valve position feedback lever; The microprocessor control unit that input signal and valve position feedback signal together enter described intelligent electric valve positioner control circuit compares computing, export a control signal to I/P electric conversion unit according to both deviations, the output pressure of control I/P electric conversion unit and the stem movement of pneumatic control valve, the stroke of valve rod feeds back to control circuit unit simultaneously, form closed-loop control, it is characterized in that described power-switching circuit is the power-switching circuit that the input current signal of 4 ~ 20mA is converted to 6V, 3V and three groups of voltages of 24V.
2. intelligent two-wire system electropneumatic valve positioner as claimed in claim 1; it is characterized in that; the power-switching circuit of described control circuit unit comprises that polarity protection and the anti-interference unit of power supply front end, linear power supply produce 6V power circuit unit, sample circuit unit, high-side current detection circuit unit, switching capacity voltage inverter generation 3V power supply unit, inductive type switching mode DC-DC transducer realization 24V power supply unit, 2.5V voltage reference and overvoltage protection unit.
3. intelligent two-wire system electropneumatic valve positioner as claimed in claim 2; it is characterized in that; described linear power supply produces in the 6V power circuit unit; one end of sample resistance links to each other with the output terminal of described polarity protection with the anti-interference unit of power supply front end; the other end links to each other with the Zener diode anode that the 6V power supply is provided; this Zener diode other end ground connection, and two electric capacity in parallel with this Zener diode are set respectively in this circuit unit.
4. intelligent two-wire system electropneumatic valve positioner as claimed in claim 2, it is characterized in that, in the described sample circuit unit, at the front end of the power circuit sample resistance of connecting, amplify by differential amplifier at the sample resistance two ends, send into microprocessor and sample, this sample resistance is the resistance that constantan wire is made.
5. intelligent two-wire system electropneumatic valve positioner as claimed in claim 2 is characterized in that, described high-side current detection circuit unit adopts the high-side current detecting amplifier of band buffering output.
6. intelligent two-wire system electropneumatic valve positioner as claimed in claim 2 is characterized in that, described switching capacity voltage inverter adopts the switching capacity voltage inverter of max1720, can produce the 3V power supply.
7. intelligent two-wire system electropneumatic valve positioner as claimed in claim 2, it is characterized in that, described overvoltage protection unit is with charge pump operational amplifier device as a comparison, its negative terminal connects the partial pressure value of 2.5V benchmark, positive termination 6V power supply, the output terminal output low level of operational amplifier, not conducting of field effect transistor, then each power circuit keeps duty; When Zener diode normally during voltage stabilizing, the positive terminal voltage of operational amplifier is higher than negative terminal, output terminal output high level, and the field effect transistor conducting, then the other end voltage clamp of parallel resistance automatically shuts down the ascending, descending volt circuit of Switching Power Supply in zero potential.
8. intelligent two-wire system electropneumatic valve positioner control method as claimed in claim 1, utilize microprocessor to interrupt and liquid crystal display operation in control circuit unit by data acquisition, button, realization is carried out switching between each pattern by button, carry out corresponding action and control strategy, parameter shows, it is characterized in that this method may further comprise the steps:
Shutdown system house dog clock generator stops regularly, and opens global interrupt;
Port initialization;
Call the liquid crystal display subroutine, the display operation result;
Carry out the A/D channel selecting, clock, timing setting, and open the A/D interruption;
The button clock is set, timing is set, open button and interrupt;
Enter low-power consumption mode of the present invention, be i.e. advance people's dormant state after the initialization, close each peripheral power supply, each function program is waken CPU up by the timer timer-triggered scheduler, carries out the conversion of analog quantity and other processing, disposing enters dormant state again, to realize reducing power consumption;
Judge current whether to arrive the A/D interrupt timing time;
Arrive as the A/D interrupt timing, then enter the A/D interruption subroutine;
Carry out the A/D interruption subroutine;
Interruption is returned, and waits for and satisfies timing next time;
Otherwise, judge whether the current time has arrived the button interrupt timing;
As this moment the button interrupt timing arrive, then enter the button interruption subroutine;
Carry out the button interruption subroutine, interrupt returning, wait for that timing arrives next time.
9. intelligent two-wire system electropneumatic valve positioner control method as claimed in claim 8, wherein said A/D Interrupt Process subroutine more may further comprise the steps:
Carry out the input signal sampling;
Judge whether current be to adopt the P6.4 sampling channel;
In this way, then preserve the A/D transformation result of current sampling;
Judge whether to finish 5 samplings;
In this way, then carrying out digital filtering handles;
The result carries out linearization process to digital filtering output;
Output signal result is set to AD1;
As not, then further judge the whether P6.5 sampling channel of current employing;
If do not satisfy 5 samplings, continue to finish signal sampling;
If current sampling channel is not P6.4, then continue to judge whether P6.5 of current sampling channel;
If then preserve the A/D transformation result of current sampled result;
Judge whether to finish 5 samplings;
In this way, then carry out digital filtering;
And linearization process;
And this output signal result is set for AD2;
If sampling number does not satisfy 5 times, then continue to finish sampling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100162651A CN100388144C (en) | 2005-03-04 | 2005-03-04 | Intelligent two-wire system electropneumatic valve positioner and control method therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100162651A CN100388144C (en) | 2005-03-04 | 2005-03-04 | Intelligent two-wire system electropneumatic valve positioner and control method therefor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1655083A CN1655083A (en) | 2005-08-17 |
| CN100388144C true CN100388144C (en) | 2008-05-14 |
Family
ID=34894207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100162651A Expired - Fee Related CN100388144C (en) | 2005-03-04 | 2005-03-04 | Intelligent two-wire system electropneumatic valve positioner and control method therefor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100388144C (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102052514B (en) * | 2010-12-17 | 2012-05-30 | 中环天仪股份有限公司 | Simple and easy control method of intelligent valve locator |
| CN102563191A (en) * | 2012-02-03 | 2012-07-11 | 深圳乐满油气技术有限公司 | Control valve group for pneumatic positioner |
| CN204270109U (en) * | 2013-03-14 | 2015-04-15 | 费希尔控制国际公司 | Comprise the control system of valve and the control system for control procedure |
| CN103256419B (en) * | 2013-04-16 | 2015-02-25 | 云南大学 | Non-oscillation high-sensitivity controller for ordinary electrically operated valve, and control method thereof |
| CN103256425B (en) * | 2013-05-31 | 2015-12-23 | 中冶长天国际工程有限责任公司 | A kind of sintering controlling method, device and system |
| CN103346755B (en) * | 2013-07-02 | 2015-08-26 | 天津精通控制仪表技术有限公司 | A kind of filtration module |
| CN104806809B (en) * | 2014-01-27 | 2017-06-13 | 上海华林工业气体有限公司 | A kind of rapid exhaust in regulating valve |
| CN104049542B (en) * | 2014-06-12 | 2016-09-07 | 曹学良 | Based on STC12C5A60S single-chip microcomputer ballast water artificial circuit plate |
| CN105156733B (en) * | 2015-07-21 | 2018-03-13 | 长飞光纤光缆股份有限公司 | A kind of automatic positioning control method |
| CN106293618B (en) * | 2016-08-24 | 2019-04-19 | 珠海格力电器股份有限公司 | Generation method, the device and system of random number |
| JP7073620B2 (en) * | 2016-10-31 | 2022-05-24 | ヤマハ株式会社 | Actuator drive control device |
| CN107191658A (en) * | 2017-06-09 | 2017-09-22 | 北京万世明科技发展有限公司 | Two-wire system realizes the method and device of solenoid valve control and state-detection |
| CN109443744A (en) * | 2017-08-30 | 2019-03-08 | 广东核电合营有限公司 | A kind of valve body characteristic check device and system applied to nuclear power plant |
| CN107957691B (en) * | 2017-12-26 | 2023-04-28 | 郑州春泉节能股份有限公司 | Electric valve proportion control device and control method |
| CN109343492B (en) * | 2018-11-08 | 2021-02-12 | 郭浩 | Two-wire system process control system protection device |
| CN111103823A (en) * | 2019-10-21 | 2020-05-05 | 阳江核电有限公司 | Nuclear power station pneumatic diaphragm valve diaphragm experimental device |
| CN112164953B (en) * | 2020-09-14 | 2022-04-12 | 四川航天燎原科技有限公司 | Crimping locator |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20010032518A1 (en) * | 1997-07-23 | 2001-10-25 | Henry Boger | Valve positioner system |
| CN2637852Y (en) * | 2003-09-09 | 2004-09-01 | 上海自动化仪表股份有限公司 | Intelligent valve locator |
-
2005
- 2005-03-04 CN CNB2005100162651A patent/CN100388144C/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20010032518A1 (en) * | 1997-07-23 | 2001-10-25 | Henry Boger | Valve positioner system |
| US20010037159A1 (en) * | 1997-07-23 | 2001-11-01 | Henry Boger | Valve positioner system |
| CN2637852Y (en) * | 2003-09-09 | 2004-09-01 | 上海自动化仪表股份有限公司 | Intelligent valve locator |
Non-Patent Citations (2)
| Title |
|---|
| 智能式电气阀门定位器. 王化祥林慧.电子质量，第9卷. 2003 |
| 智能式电气阀门定位器. 王化祥林慧.电子质量，第9卷. 2003 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1655083A (en) | 2005-08-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100388144C (en) | Intelligent two-wire system electropneumatic valve positioner and control method therefor | |
| CN103744467B (en) | For solar cell maximum power tracing device and the control method thereof of miniature satellite power system | |
| Ang et al. | Power-switching converters | |
| CN201674399U (en) | Low-ripple power source device | |
| CN103079323B (en) | Non-isolated LED (Light Emitting Diode) drive circuit not powered by auxiliary winding | |
| CN103605035B (en) | The no load detection circuit structure of self-adaption switch electric power source | |
| CN103475223A (en) | Step-down converter | |
| CN203279254U (en) | LED driving circuit and constant current control circuit thereof | |
| CN105827112A (en) | BUCK converter having low power consumption characteristic | |
| CN105667429A (en) | Automatic voltage stabilization control and protection method, device and system for vehicle-mounted generator | |
| CN102520241A (en) | Three-phase charge-controlled electric energy meter based on resistance-capacitance voltage reduction and low-voltage direct-current/direct-current (DC/DC) power supply | |
| CN103343831A (en) | Intelligent electrical valve locator main board hardware circuit | |
| CN108762158A (en) | Efficient numerically controlled DC power supply and its test method based on the design of MSP430 microcontrollers | |
| CN204145296U (en) | A kind of DC numerical control power supply | |
| CN206072476U (en) | A kind of valve control device adjusted for fluid flow | |
| CN202550969U (en) | Two-way digital proportional valve amplifier | |
| CN204559392U (en) | The booster driving circuit of comprehensive wiring system current feedback | |
| CN204559380U (en) | For the load driving circuits that the input of managing system of car parking is boosted | |
| CN200976642Y (en) | LCD TV electrical source | |
| CN208268153U (en) | cylinder debugging tool plate | |
| CN107786076A (en) | Microprocessor control system and its control method | |
| CN2850129Y (en) | DC-DC converter | |
| CN202550968U (en) | Open-loop digital proportional valve amplifier | |
| CN207603450U (en) | The control circuit and switching circuit of Switching Power Supply | |
| CN206164935U (en) | LED driving circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Dalian Maxonic Electric Apparatus Co., Ltd. Assignor: Tianjin University Contract record no.: 2010120000104 Denomination of invention: Intelligent two-wire system electropneumatic valve positioner and control method therefor Granted publication date: 20080514 License type: Exclusive License Open date: 20050817 Record date: 20100819 |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080514 Termination date: 20210304 |