GB2491394A - Pressure control of pressurised air supply - Google Patents
Pressure control of pressurised air supply Download PDFInfo
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- GB2491394A GB2491394A GB1109284.8A GB201109284A GB2491394A GB 2491394 A GB2491394 A GB 2491394A GB 201109284 A GB201109284 A GB 201109284A GB 2491394 A GB2491394 A GB 2491394A
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- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
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Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D16/00—Control of fluid pressure
- G05D16/20—Control of fluid pressure characterised by the use of electric means
- G05D16/2006—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means
- G05D16/2013—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means
- G05D16/2026—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means with a plurality of throttling means
- G05D16/2046—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means with a plurality of throttling means the plurality of throttling means being arranged for the control of a single pressure from a plurality of converging pressures
- G05D16/2053—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means with a plurality of throttling means the plurality of throttling means being arranged for the control of a single pressure from a plurality of converging pressures the plurality of throttling means comprising only a first throttling means acting on a higher pressure and a second throttling means acting on a lower pressure, e.g. the atmosphere
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D16/00—Control of fluid pressure
- G05D16/20—Control of fluid pressure characterised by the use of electric means
- G05D16/2006—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means
- G05D16/2013—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means
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- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Control Of Fluid Pressure (AREA)
- Measuring Fluid Pressure (AREA)
- Measuring Arrangements Characterized By The Use Of Fluids (AREA)
Abstract
An apparatus 10 and method for supplying pressurised air to a testing facility, the apparatus comprising a supply inlet 12 for receiving air under pressure from a pressurised air source 14, an outlet 16 in fluid connection with the Inlet 12, for supplying air at a target pressure to the testing facility, a supply valve 26 for regulating the flow of air between the supply inlet 12 and the outlet 16, a first air pressure sensor 34 for determining the pressure of air supplied to the supply inlet:12 a vent valve 30 disposed between the supply valve 34 and the outlet 16, for venting air from the Apparatus 10, a second air pressure sensor 38 for determining the pressure of air exiting the outlet 16, and a controller 22 operable to receive a target air pressure profile to be output by the apparatus 10, and signals of air pressure from the first 34 and second air 30 pressure sensors, and to control the supply valve 26 in response thereto to as to regulate the flow of air therethrough so as to minimise any differential between the target air pressure and the pressure of the air leaving the outlet 16 at any point in time.
Description
Title: Apparatus and: methcd.for.supplying pressurised air to a testing facility.
escitionoflrjvefltiofl The inventiOn relateS tb T Bfl apparatiisfor suppying.pressurised air to: atesting facility, and to a method for the same The invention relates, in particuIar but not exclusively, to an apparatus and method for supplying pressurised air to a testing facility for simulating conditions in an aviation environment Many devices and equipment used onboard aircraft require pressurised air sources to be able: to operate. One such ex'ample is an on board oxygen generating apparatus (or "OBOC") another would be an Environmental Control System Typically, pressurised air is bled from a compression section of a gas turbine engine of an aircraft to provide pressurised air to an 080G. The pressurised air produced from the engines has a stiffness' quality, wherein the pressure produced is so great, and the vbl.ume produced is so high, that bleeding off a relatively small amount of the pressurised air has ttle or no effect on the operation of the engine or the pressure of the air available for delivery. The pressurised air produced frç..rn the engines is also capable 91 high rates of change: of pressure and temperature.
In facilities for testing devices requiring pressurised air, it is desirable to simulate the conditions tnat are produced by bleeding off air from an aircraft engine, as this is how the air will be supçlied in use. Previous methods of providing pressurised air to a testing facility include running an engine in order to reproduce the effect This method is costly, as expensive fuel must be burnt in order to operate the engine. Furthermore, it is expensive to supply, maintain and. operate an engine for testing purposes, and it is not environmentally friendly to do so.
Simulation systems have been proposed in Which air from a p.ressurised air Source k controlled so as to reproduce the effect of the pressurised air from an engine. It is relatively simple to design a system t control the pressure of air supplied to a tesUng facility at a single set point, but no previous systems have been able to simulate accurately and efficiently a pressure profile to correspond with the changing pressure condiuons that may be experienced in use with suitably high transient response performance and fidelity in order to simulate a target air pressure profile, apparatus is provided to 10. control the flow of air from. pressurised air' source (such as a bank of compressors) to a testing facility It is known for the apparatus to include a supply' valve between. the source of the: pressurised air and the outiet to the testing facility, so that the pressure of the air passing through the apparatus a nbe controlled.
One method of controfling ihe pressure of air passing through the apparatus is to employ a feedback algorithm to minimise the difference between the observed pressure of the air leaving the outlet, and the target air pressure. A common way to achieve: this is by using a proportio.naF-integral-deilvative (RID) controller to calculate a control signal to control the supply valve PID controllers aim to minimise an Lerror in this case the difference at a point in time between the air pressure being supplied by the system and the target air pressure.. To achieve' this, the error at any moment in time: is evaluated in three' separate components.,. to produce a control signal.: .a' "proportional' component that is directly proportional to the observed error! an integral component that represents the history of the error observed, and a "differential" component that represents the, current rate of change. in the error.
Each component is scaled by a constant, and combined to achieve an output control signal desigped to: minimise the error over time.
A PID controller is configured so that the constant by which each component is scaled is suitable to a:chieVe.a smooth and accurate transition in Output to a target value over time. The responsiveness ot the system in ie:rirs of the length of time taken to settle on a target output value, and the degree of error S in: the output value UhtiI the target is reached depends on the: nature. of the variabIE,s being measured..
A problem with known air pressure controi systems is that although they are capable of achieving a target air pressure over time, they are generally optimised for use with a particular source of pressurised air and the system under test and to achieve a particular target value Typically, air pressure control systems do not react quickly to a change in the target pressure, and a fluctuation, in. the target. can: lead to a sudden. change in the output from. the system, which is likely to overshoot' the target pressure, and then osciflate about the target value for an undesirable period of time.
Where a target air pressure is determined from a target profile, such as a continuous model of varying target pressures, or a stepped model in which the target value changes at discrete intervals, there is a need to achieve each targel. pressure: quickly a'Ad.E.cu.ratdly Known systems are unsuitable. Ipi: this purpose, as by the time a steady state target output value has been achieved (if at all)) a new target has been set by the target profile As a result, the system c.utputs inaccurate air pressures for a large propfln of the time.
This renders the apparatus impractical for testing devices which rely on a pressu'rised source of air, thief. as an OB.OG for use in aircraft According to an aspect of the invention we provide a method for controlling an apparatus for supplyin pressurised air to a testing facility, the apparatus comprising a supply..inlet.for receiving air under pressure fro.m a pressurised air scurce,, an outlet in fluid connection With. the. inlet, for supplying air at a target pressure to the testing facility, a suppi va've for regulating the flow of &r between the supply inlet and the outlet, a first air pressure sensor for det.trtuining the pressure ct aft scpplied to tf supply inlet, a vent vaIve disposed between the supply valve and the outlet, for venting air from the apparatus, a second air pressure sensor for determining the pressure of air exiting the outlet, and a control means for receiving an indication of a target air pressure, the method including receiving from a control means a target air pressure profile to be output by the apparatus, receiving from the first and second air pressure sensors a signal of the air pressure of the air supplied to the apparatus, and a signal of the air pressure of the air output by the apparatus, respectively, determining a control signal, and controlling the supply valve according to the control signal so as to regulate the flow of air thërethrough so as to minimise any differential between the target air pressure and the pressure of the air leaving the outletat any point in time.
According to another aspect of the invention we provide an aplparalus for supplying pressurised air to a testing facility, the apparatus comprising a supply inlet for receiving air under pressure from a pressurised air source, an outlet in fluid connection with the inlet for supplying air at a target pressure to the testing facility, a supply valve for regulating the flow of air between the supply inlet and the outlet, a first air pressure sensor for determirnng the pressure of air supplied to the supply inlet, a vent valve disposed between the supply valve and the outlet, fOr venting air from the apparaius: a second air pressure sensor for determining the pressure of air exiting the outlet, and a controller operable to receive a target air pressure profile to be output by the apparatus, and signals of air pressure from the first and second air pressure sensors, and to control the supply valve in response thereto so as to regulate the flow of air therethrough. so as to minimise any differential bezeen the target air pressure. and the pressUre of the air leaving the outlet at any point in 30. tima Further features for the' first and second aspects of the invention are set out in the claims appended hereto..
Embodiments of the invention will now be described by way of example only, with reference to the accompanying figures, of which Figure us a flow diagram of a controfler of the type known from the prior art, Figure 2 isa diagram' of the apparatus of the. resent. invention.; Figure 3 is a flow diagram of a controller according to the present invention, Figures 4A to 7A are graphs showing the performance of traditional PID controlled pressurised air supply systems in response to a change in target pressure value (psi9 I sac),, at increasing levels ofsource air pressure supplied to the system; and Figures 48 to 7B are graphs showing the performance Of the method of the present invention in response to a change in target pressure value (psig / sec), at levels of source air pressure supplied t the' system corresponding to those of. Figures 4A to 7A, respectively.
An apparatus 10 for supplying pressurised air to a testing facility comprises a supply inlet 12 for receiving air under pressure from a pressurised air source 14, and an outlet 16 in fluid connection with the inlet 12 The apparatus also includes a supply valve 26 for regulating the flow of air from the pressurised air source 1.4 intO the apparatus, a first air pressu.re'sensor 34 for deterrnht.ing the pressute of source air sUpplied to the apparatus.,, a vent valve 30. disposed between the supply valve 26 and the outlet 16, for venting air from the apparatus, a second air pressure sensor 38 for determining the pressure of air output by the apparatus to the testing facility,, and a control means 18 for receiving a target air pressure.
Figure 1 shoWs a controller of the type knowd from the prior art. A; controller ii I is shown having a cOntrol means I 8 for recEiving a target air pressure to be output by the apparatus,. a supply outlet 24 and a vent 28. The target air pressure may be supplied to the confrpl rriean:s I B by a user or may be 51 generated autorAatkal!y by asimuIatIon.ctntcoI.Ier.
The controfler 11 receives a signal 38 of the air pressure of the air currently being output from the apparatus through the outlet 16, and this is used to calculate the current terrpr' in performance. In other words. the controller determines the difference 40, at a point in time, between the target air pressure and the air pressure of air leaving the outlet 16 That error is input to a PID controller 59, and passed to each of a proportional component 46, an integral component 48, and a derivative component 44 A configurable weighting factor, stored as a constant Cl, C2, ca, is applied to the error value input to each of the components, so that the relative contribution each cbrr.ponent makes to the control of the apparatus may be increased or decreased? The proportional component 46 is a value indicative of the current error, scaled 2G by' its respective constant, 02..
The integral component 48 is a value indicative of the past errors over time (i e the integral of the error term), scaled by constant Cl The integral output value is determined by calculating the integral of the error with respect to time The effect of the integ.raF value is to cause the change in output value to accelerate towards' the. target value, but this may lead to overshoot r.ast the target value, since the contribution of the integral component is based on past errors rather than the current error. To lessen the impact of this overshooting, the integral value is limited according to a fixed-limit anti-wind-up logic component: 51 to prevent integral component rising outside aboye a pm-determined magnitude aLue.
The derivative component 44. is a value indicaflve of the current rate of change of the error, and has. th.e effect lessening the effect of overs:hOOt caused by the. integral coi'n�b.heflt. The derivative, component is determined by caI*culating the. derIvative. of the error valuö against time, scalec. by Constant ca. The values output by the proportional 46, uitegral 48 and derivative 44 components are then combined 52 to deterrmne a control signal to be output to a supply valve controller 24 The supply valve controller 24 controls the supply valve 26 so as: to open or close it açcqrd'i'ng to the control signal, to regulate the flow of air therethrough from the source of pressurised air A vent 1.5 control signal is also determined by the apparatus, according to the same combined valUe 52 oUtpUt. by the PID controller 59. Typically, the vent control signal is inversely proportional to the control signal, such that the air pressure in the apparatus is: increased by opening the supply ValVe.26 and simultaneously closing the vent valve 30, and decreased by opening the vent valve 30 and closing the supply valve.26,.
The apparatus and method of the present invention shall now be described with, reference to Figures 2 and 3 Figure 2 shows an apparatus for supplying pressurised air to a testing facility, includbig the features as generall.y described above. In addition to those.
features, the apparatus further inOludes a third sensor 36 that: is disposed adjacent the exit of the vent (La not within the portion of the apparatus through which pressurised air flows), for determining the pressure of atmospheric air surrounding the apparatus a A workstation 1. may be connected to the controller 22, so that a user may input a target air pressure profile to the controller 22. AItemalively. the workstation 18 may store a target air pressure. profile, and provide updated v&ues representing the: required air pressu re outputto the controller 22 oVer t*iinë.. A further WdtkstatiOn 2O or alternatiVely the same workstation 18, may receive signals of the air pressUre of the e*it flowing through the OUtlet. 16 f:p1rh: the second air pressure sensor, to allow an operator to monitor the performance of the apparatus 10, The. controller 22 Ts shavEn In Figure 3 The cOntroller 22 receives a signal of the air �ressure of the air currently being: output from the apparatus,. from the second: air pressure. sensor 3. The current Eerrort in performance is then determined, by calculating the difference 40 at that point in time between the target air pressure and the air pressure being achieved. That error is then scaled by a volume compensation factor 42, according to the volume of the apparatus downstream of the supply valve 261 and vent valve 30. This compensating factor accounts for the fact that if the volume of the pressunsed air dcwnstream: cf the: valves is large, changes to the air pressure must be made to a relativdy large volume of air compared to a scenario in which the volume: is smaller.: Therefore, larger correcting measures must be taken to MfEIct:the. pressure nra larger:Volun::e.Of: air,: and vice versa.
The: value output from the volume compensation calculation is then provided as an input to two PlO controllers 60, 160 for determining values: to control the suppIy valve 26 and vent valve 30, respectively. Each PID contrOller 60, 160 provides the input Value, to each of a proportional component 46 1464 an integral component 48, 148 and a derivative co mponent:44, 144. The values are then scaled by a pnfigurable constant Cl,, C2, :C3, C4, :Q5 Ct stored for each of the components. This scaling:constaflt: allows each of the proportional 46, 146, integral 48. 148 and derivative 44, 144 components to be given a different weighting, so that the performance of the PID controller may be configured to optimise performance.
S The: proportional corn ponent 46, 146 i. scaled by its respective constant 02.
CS. The integral component 48., 148. is. scaled by its respective constant Cl,.
04, and is, subject to limiting by an antiwi.'nd-up logic component 50, 150 to.
prevent the integral component rising above a certain vahie.. The. derivative component 44, 144 is determIned by. calculating the derivative of the: error value against time, and scaled by its respective.constant C3, 06.
The values output by the components of' each PID controller 60, 160 are eaph then combined 52, 1.52.. Finally! first 54 and second 154 dynamic gain units receive the combined outputs of the first 60 and second 160 PID controllers, respectively. Each dynamic gain unit 54., 1.4 also receives the target profile value representing the air pressure to be achieved. In addition, the first direct gain unit 54 also receives the signal of air pressure from the first air pressure sensor 34, and determines a control signal to be output to the supply valve controller 24 according to the combined output of:the PID controller 60, the target profile! and the signal of aIr pressure from the first air pressure. sensor 34. This dynamic gain allows the controller to parUally override over-enthuSstic corrections to errors' input t.o the. PID controller (for example in a situation where the target air pressure value has almost been reached, yet a large: correction has been generated due to past errors, or because an over-correction has already been made). This 4sanitycheck on the value: output to the supply valve controller 24 helps to lessen the problem of over-shooting' the target, and also damps oscillations iii the output air pressure once the target value has been reached.
The second dynamic gain unit 154 operates in a similar manner, determining a vent control signal to output to the vent controller 28 according to the. output.of the second PID controller 160, the target profile, and the signal of air pressure from the third air pressure sensor 34. By. taking into account the current air 5: pressure of atmosphetic air, the vent valve controller 28 can be operated more effectively, as the effect of o�ening and closing the vent valve.0 on the pressure within the apparatus is dependent in part on the pressure differential with the atmospheric air outside the apparatus..
To balance the effect. of applying dynamic gain to the, control signal. and vent control signal, the limits, imposed by the PlO controllers 60, 160' on' the. integral component by the. anti-wind-up logic components 50, 150 are determined dynamically according to the same dynamic inputs as their respective dynamic gain units 4, 154. The anti-wind-up logic component 50 of the first P1D controller 60 determines a limit on the integral component according to the target profile, and the signal of air pressure from the first air pressure sensor 34. The anti-wind-up logic component 150 of the second PID controller 160 determines a limit on its respective integral component according to the target profile, and the signal o. air pressure from' the third air pressure sensor 34. By applying dynamic gain to the value' output from the PID controller, and :determini:ng the limit to impose on the integral component of the PlO controller determined dynamically bn the same basis, over-accentuated corrective fluctuations in the control gnal an,d want control signal are avoided.
An ad Vantage of the apparatus and method according to the present invention, is that the application of' dynamic gain, bSnced by the dynamic: limiting applied to the values determined by the integral components of the' PlO controllers, results in a rapid yet smooth' transition from a first target air pressure to a second target air pressure. This allows the apparatus to be used to provide pressurised air for a simulation in which the air pressure changes Ii: over time, either at di&rete time intervals, or corWnuously over a time period.
The air pressure output by the apparatus is adjusted rapidly by applying dynamic gaIn, but does not overshoot to fly great extent! in party because of thedynamic determiriatidh of the limit On the inteçral components.
S
Fudhermcre. Dy. providing separata: PIP. controllers for each of the &pply vaI\s 26 and the vent valve 30, the: appsratu:s Can be n.ore responsive to the changThg air pressure. This is becauSe the valves can be c.pe.rated in combinatiOn, to better control a change i air pressure., rather than operating the valves according to a single control value (i e opening one and simultaneously closing the other).
A further advantage of the apparatus is that the apparatus vOlume, air pressure of the air supplied to the apparatus, and atmospheric air pressure are afl taken into account when determining how to control the valves. This enables greater precision when determining how to control the valves based :n the past and current rates of change in the differential between: the target airpressure and the achieved air pressure outputfrom the outlet 16.
Figures:4A and 4B of the drawings are graphs showing the. performance of a tradifional PlO controlled pressurised air supply apparatus (Figure 4A) and the apparatus of the present invention (Figure 4B) in response to a change in target pressure value (psig / eec) As. the target pressure changes, the pressUre' output by the appäràtus changEs accordingly, reaching the target pressure and levelling cff at that pressure. Figures4A and 4B showthat, for a particular pressure of air supplied by the pressurised air source, the traditional P10. controlled apparatus performs at the same, or a similar, level to the apparatus and method of the present inventiOn. This is because the traditional system can be optimised to perform weM with a particular air pressure supply. ao
Figures 5A and SB, 6A and 68, and 7A and 7B show corresponding graphs: for SF) identica' simuiatin each performed under an increased supp. 1Y pressure (frOm the pressurised air source), with the grapPs of Figures IA and 7B showing the simu'ation performed with the highest pressure air source These graphs illustrate the smooth transitions achieved by the apparatus and method of the present invention, wherein the target air pressure is achieved and the output air pressure stabilised far more rapidly than by the corresponding traditional apparatus..
Figure 7A shows that when the air supplied to the apparatus is under a very high pressure, traditional methods of controlling the output from the apparatus fluctuate dramatically about the target air pressure. This is due to over-correction being performed, and due to the nature of traditional PID control methods, the over-correction results in large oscillations about the target value as the apparatus struggles to limit the impact of the large (and slowly decreasing) corrections imposed by the integral component. It can be.seen from the graph that not only does the apparatus struggle to reach and maintain the target air pressure, but by the time the target profile value has changed to a different air pressure3 the previous:: air pressure may not have been achieved This means that when a simulation requires a changing air pressure, a traditional PID controlled air pressure supply apparatus and method will likely fail to achieve the required output air pressure throughout the simulatim In contrast, the graph Of Figure 78 shoWs that the apparatus and method, of the present invention achieves the required air pressure relatively quickly, and although the output air pressure over-shoots the target pressure by a small arhount, this error is rapidly corrected and the air pressure maintained at the dósired level with little or no oscillation. 30:
When used in this specIfication and claims, the terms "comprises" and comprisingnl and variations thereof mean that the specified features, steps or integers are included., The terms are not to be interpreted to exclude the presence of other feature.s, steps or com'p.ene.nts.
The features disclosed in the foregoing description, or the following claims1, or the accompanying drawings expressed in theft specific forms or in terms of a.
means for pertrming the disclosed functions or a method or process for attaining the disclosed result, as *appropriatQ m.ay separately, or in any combination of such features, be utilised for realisi.ng the invention, in diverse forrn.s thereof.
Claims (7)
- CLAIMS1. A method for controlling an apparatus for supplying pressurised air to a testing facility, the apparatus comprising: S a supply iplet for receiving air under pressure from a pressurised air source, an outlet in fluid connection with the inlet, for supplying air at a target pressure to the testing. facility, a supply Valve for regulating the flaw of air between the supplyinlêt and IC. the outlet1 a first air pressure sensor for determining the pressure of air supplied to the supply inlet, a: vent valve diéposed between the supply valve and the: cutlet, for venting air from the apparatus, H 1:5 a second air pressure sensor for determining the pressure of air exiting the outlet, and a control means for receiving an indication of a target air pre,ssure the method including: receiving from a control means a target air pressure profil.e to be output by the apparatus, receiving from the first and second air pressure sensors a signál.bf the air pressure of the air supplied to the apparatus, and a signal of the air pressure of thE: air output by the apparatus, respectively, determining a control signal, and controlling the supply valve according to the control signal so as to regulate the flow of air therethrough so as to minimise any differential between the target air pressure and the pressure of the air leaving the outlet at any point in time.
- 2. The method of cam 1, wherein the target air pressure profile Is one of o.r a combination of: a single value, a plurality of values and associated time intervals, and a continuous gradient of target ai.r pressure values.5.
- 3. The method of claim I or claim 2 wherein the step of determining a control signal comprises, determining a control signal according to the. signals f the air pressures received from the first and second air pressure Sensors and the target air pressure profile.
- 4, The method of any one of the precedir.g daims. further comprising the steps of determining a ventcontrol signal, and controlling the vent valve according to the vent control, signal so. as to regulate the air vented from the apparatus.
- 5. The method of claim 4, wherein the step of determining a vent control signal comprises determining a vent control signal according to the signal of the air pressure received from the second air pressure sensor and the target profile.
- 6. The method of claim 4, wherein' the apparatus further comprises a third air pressUre sensor disposed ad jacent.the. exit of the vent' for determining the: pressure of atmospheric air, and the step of:deterrnining a vent control Signal compdses determining, a. vent cpntro! signal. according to the signals of the. air pressures: received, from the second and. third aft pressure: sensors and the target profile.
- 7. The method of any One of the precedllng claims, wherein the step of determining a control signal comprises determining a component of the control signal using a first proportional-integral-derivative controller to minimise the difference over time between the target profile and the signal of air pressure received from the second air pressure sensor. I 5& The method of claim 7 wher&n the step of determining a vent control sIgnaJ comprises detmining a component of the vent cOntrol signal using a secondS proport[onal-integral4erivative controller to minirnisc the difference over time between. the target profile and the sign:aI of air pressure received from the second ai.r pressure sensor.91 The method of claim 7 or daim B wherein determining a component cf. the control signal comprises Umiting an integraL component determined by the first proportionakntegral-derivative controller subject according to the signal of air pressure received from the fist air pressure.:seflsor and the target profile..10. The method of any one of claims 7 to' 9, where dependent dfrectiy or indirectly on claim 6, wherein determining' a component of the' vent control signal comprises limiting an integral component determined by the second proportional-integral-derivative controller according to the signal of air pressure received from thethird afrpressure sensorand:,the target profile.ii. The method f any one of the preceding claims where dependent directly or indirectly on claim 7 or claim 8:, wherein:the. step cf determining a control signal comprises applying dynamic gain to a value output from the first proportional-integral-denvative controller, such that the control signal restores the system pressure' to. thetarget profile,.12. The method: of olaim ii., wherein a component of the control signal is proportiOnal to the. sIgnal. cf air pressure rcceivsd from the first air pressure sensor.13. The method of any one of the preceding claims where dependent directly or indirectly on claim 7 or claim 8, wherein the step of determining a vent çpntrol signal comprises applying dynamic gain to a value cutput from the second proportional-integral-derivative controllers such that a corn ponent of the vent control signal is proportiona.l to the target. profile.14. The method of claim 13, where dependent directly or indirectly on claim 6, wherein.a component of the vent control signal is proportional to the signal of air pressure received from the third.air pressure sensor.1.5. The mthod of any one of the preceding claims where dependent directly or indirectly on dàim 7 or claim 8, wherein the step of determining a component of the control signal using a first proportional-integral-derivative controller comprises scaling the target profile. and the signal of air pressure received from the second air pressure sensor by a value proportional to the volume of the apparatus.downstream of the supply valve and vent valve.1.6. The method of any preceding claim wherein the testing facility is for testing devices and/or apparatus for aircraft which rely on a pressurised afr sourCe..17.. An apparatus for supplying pressurised air to a testing facility, the 2Q apparatus.com prisng:: a supply inlet, for receiving air under pressure from a pressurised air source, an outlet in fluid connection with the Inlet, for supplying air at' a target pressure to the testing facility, a supply valve for regulating the flow of air between the. supply inlet and the outlet, a first air pressure sensor fOr determining the pressure of air supplied to the supply inlet, a vent valve disposed between the supply valve and. the outlet, for venting airfrom the apparatus, a second air pressure sensor for determining the pressure of air exiting the outlet, and a controller operable to receive a target:a.ir pressure profileto be output by the apparatus1 and signals of air pressure from the first and second air pressure sensors, and to control the supply valve in response thereto so as to regulate the flow of air therethrough so as to minimise any differential between the target air pressure and the pressure of the air leaving the OL.Uet at any pointin tune.18 The apparatus of claim 17, further comprising a third air pressure sensor for determining. th.e pressure of atmospheric air at an exit of the vent valva 19: A method substantially as described herein and/or with reference to Figures 2, 3, 4B, 58, 68 and 7B of the accompanying drawings.2ft An apparatus substantiafly as described herein and/or with reference to F1:guieS 2, 3, 4B, 58, 68 and lB of the accompanying drawings.21. Any novel feature or novel combination of features described herein and/or in Figures 2, 3,, 4B, 581, W ad lB of the accompanyin.g drawinga
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1109284.8A GB2491394A (en) | 2011-06-02 | 2011-06-02 | Pressure control of pressurised air supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1109284.8A GB2491394A (en) | 2011-06-02 | 2011-06-02 | Pressure control of pressurised air supply |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201109284D0 GB201109284D0 (en) | 2011-07-20 |
| GB2491394A true GB2491394A (en) | 2012-12-05 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1109284.8A Withdrawn GB2491394A (en) | 2011-06-02 | 2011-06-02 | Pressure control of pressurised air supply |
Country Status (1)
| Country | Link |
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| GB (1) | GB2491394A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106054955A (en) * | 2016-05-18 | 2016-10-26 | 中国航空工业集团公司西安飞机设计研究所 | Multi-air source system flow balance controlling apparatus |
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| WO1999040360A1 (en) * | 1998-02-04 | 1999-08-12 | Gas Research Institute | Adaptive system for predictive control of district pressure regulators |
| US6519938B1 (en) * | 1998-12-22 | 2003-02-18 | Coltec Industries Inc. | Recording and controlling pneumatic profiles |
| JP2003076429A (en) * | 2001-08-31 | 2003-03-14 | Hitachi Hybrid Network Co Ltd | Automatic pressure control device |
| JP2004263847A (en) * | 2003-02-28 | 2004-09-24 | Hitachi Hybrid Network Co Ltd | Pressure control unit |
| US20050120805A1 (en) * | 2003-12-04 | 2005-06-09 | John Lane | Method and apparatus for substrate temperature control |
| WO2008140537A1 (en) * | 2006-12-13 | 2008-11-20 | Alcon, Inc. | Adjustable pneumatic system for a surgical machine |
| CN201297647Y (en) * | 2008-11-19 | 2009-08-26 | 攀枝花新钢钒股份有限公司 | Pipeline pressure control system for combustible gas |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999040360A1 (en) * | 1998-02-04 | 1999-08-12 | Gas Research Institute | Adaptive system for predictive control of district pressure regulators |
| US6519938B1 (en) * | 1998-12-22 | 2003-02-18 | Coltec Industries Inc. | Recording and controlling pneumatic profiles |
| JP2003076429A (en) * | 2001-08-31 | 2003-03-14 | Hitachi Hybrid Network Co Ltd | Automatic pressure control device |
| JP2004263847A (en) * | 2003-02-28 | 2004-09-24 | Hitachi Hybrid Network Co Ltd | Pressure control unit |
| US20050120805A1 (en) * | 2003-12-04 | 2005-06-09 | John Lane | Method and apparatus for substrate temperature control |
| WO2008140537A1 (en) * | 2006-12-13 | 2008-11-20 | Alcon, Inc. | Adjustable pneumatic system for a surgical machine |
| CN201297647Y (en) * | 2008-11-19 | 2009-08-26 | 攀枝花新钢钒股份有限公司 | Pipeline pressure control system for combustible gas |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106054955A (en) * | 2016-05-18 | 2016-10-26 | 中国航空工业集团公司西安飞机设计研究所 | Multi-air source system flow balance controlling apparatus |
| CN106054955B (en) * | 2016-05-18 | 2019-05-24 | 中国航空工业集团公司西安飞机设计研究所 | A kind of multiple air supply system flow balance controller |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201109284D0 (en) | 2011-07-20 |
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