EP0783677A1 - Testable membrane sensor with two full bridges - Google Patents

Testable membrane sensor with two full bridges

Info

Publication number
EP0783677A1
EP0783677A1 EP96922746A EP96922746A EP0783677A1 EP 0783677 A1 EP0783677 A1 EP 0783677A1 EP 96922746 A EP96922746 A EP 96922746A EP 96922746 A EP96922746 A EP 96922746A EP 0783677 A1 EP0783677 A1 EP 0783677A1
Authority
EP
European Patent Office
Prior art keywords
bridge
measuring
sensor
membrane
resistance
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.)
Ceased
Application number
EP96922746A
Other languages
German (de)
French (fr)
Inventor
Erich Zabler
Herbert Keller
Joerg Wolf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP0783677A1 publication Critical patent/EP0783677A1/en
Ceased legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
    • G01L9/0051—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance
    • G01L9/0052—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance of piezoresistive elements
    • G01L9/0055—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance of piezoresistive elements bonded on a diaphragm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/17—Using electrical or electronic regulation means to control braking
    • B60T8/171—Detecting parameters used in the regulation; Measuring values used in the regulation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
    • G01L9/0051—Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R17/00—Measuring arrangements involving comparison with a reference value, e.g. bridge
    • G01R17/10—AC or DC measuring bridges
    • G01R17/105—AC or DC measuring bridges for measuring impedance or resistance

Definitions

  • the invention relates to a sensor, in particular a pressure sensor according to the preamble of the main claim.
  • Pressure sensors are known, for example, in which thin-film resistance measuring bridges for measuring absolute pressures or pressure changes, in particular in hydraulic systems, are arranged on a measuring membrane. Movements of the measuring membrane due to pressure fluctuations lead here to changes in resistance in the respective thin-film resistors due to compression or stretching of the generally meandering resistance tracks.
  • the thin-film resistors are connected in a known manner to form a Wheat ⁇ ton measuring bridge, the assignment of the thin-film resistors to the bridge branches or to the areas on the pressure sensor membrane being chosen such that the opposing resistances change in the same sense and a bridge diagonal voltage is al Sensor signal is measurable.
  • an accurate output signal corresponding to the pressure of the brake hydraulics must be highly reliable and, if possible, also fail-safe.
  • sensors are required, the proper functioning of which must also be continuously verifiable. Further applications are monitoring functions in pneumatic systems and in injection systems for the fuel supply in motor vehicles.
  • the resistances of the measuring bridge which change in the same direction, are preferably located on the pressure measuring membrane at locations with the same mechanical properties with regard to tensile / compressive strain (either in the middle or on Edge of the pressure measuring membrane) and are therefore loaded equally; their deviations behave accordingly. Plastic deformations of the pressure measuring membrane also show the same, undetectable signal errors. Another known possibility of recognizing such errors is to compare the individual resistances, which are repeated at certain intervals, with a stable reference resistor.
  • the reference resistor which is stable over the entire service life, can be connected in parallel to a bridge resistor and can therefore be used to monitor changes in the bridge output signal.
  • the known sensors with the special monitoring mechanisms have the particular disadvantage that there must be a constant switch between the test / monitoring module and the pressure sensor, since the dynamics of the sensor are greatly reduced since the reference measurement takes time. Furthermore, demands for reliability and redundancy cannot be met in this way.
  • the sensor according to the invention of the type specified at the outset is particularly advantageous with the characterizing features of claim 1 in that, by arranging two mutually independent resistance measuring bridges on each membrane half, a check of the functionality of the sensor during operation without particular reference measurements can be done. In addition, the availability of the sensor increases, since even if one of the resistance measuring bridges fails, an emergency operation of the system with the other measuring bridge is guaranteed.
  • the thin-film resistors of at least one of the two resistance measuring bridges are arranged on the measuring membrane such that radial expansions / compressions of the measuring membrane lead to an increase or decrease in resistance.
  • the thin-film resistances opposite each other in the bridge are arranged on the measuring membrane in such a way that a tangential strain is detected in the edge area of the membrane and this leads to an increase in resistance.
  • the two measuring bridges behave differently over the service life with regard to the bridge diagonal signal according to the above-described embodiment, since the thin-film resistances for detecting the tangential expansion detect a different membrane movement than the radial expansion or compression, a simple comparison can be made by comparing the two bridge signals Functional check done. Plastic deformations of the pressure measuring membrane can also be clearly identified in the bridge offset, since the two bridge diagonal signals thereby drift clearly apart. Signs of aging as well as mechanical or physical-chemical effects influence the sensitivity of the two bridges differently, so that they can be identified by comparison.
  • FIG. 1 shows a plan view of a measuring membrane of a pressure sensor
  • FIG. 2 shows an electrical circuit diagram of the right measuring bridge
  • FIG. 3 shows an electrical circuit diagram of the left measuring bridge
  • FIG. 4 shows a detailed image of a thin-film resistor
  • Figure 5 is a diagram of the mechanical stresses / strains on the measuring membrane.
  • FIG. 1 shows a sensor 1 which serves as a pressure sensor for detecting the pressure conditions in the brake hydraulics of a motor vehicle.
  • the sensor 1 contains a measuring membrane 2 (for example made of metal) on which thin-film resistors R1, R2, R3 and R4 (for example made of polycrystalline silicon) are applied to each of two sensor halves 3 and 4.
  • the thin-film resistors R1 to R4 are contacted on the measuring membrane 2 at points 5 and for the external connection, the points 5 are each brought into contact pads 6. This is shown in FIG. 1 for the sake of a better overview only because of the resistance R1 of the right sensor half 4, for example.
  • FIG. 2 and FIG. 3 show the electrical equivalent circuit diagrams of the resistors R1 to R4 on the sensor half 3 (FIG. 2) and the sensor half 4 (FIG. 3), which each form a Wheatstone measuring bridge 7 and 8, respectively.
  • the sensor diagonal voltages Um1 (FIG. 2) by Umr (FIG. 3) are available for the sensor output signal.
  • FIG. 4 shows an exemplary embodiment of one of the thin-film resistors R1 to R4, in which the meandering structure of resistance paths 9 between points 5 can be seen.
  • the resistors R1 to R4 experience a change in their resistance value (+ ⁇ R) with an elongation (+ ⁇ l) in the direction shown.
  • a different geometrical structure can also be selected to achieve the same measurement effect.
  • FIG. 5 shows a diagram of the courses of the mechanical stresses ⁇ caused by pressure changes and the resulting strains or compressions ⁇ in radially different areas of the measuring membrane 2. An explanation of this diagram is given using the description of the exemplary embodiment, in particular with reference to FIGS. 1 to 3.
  • the bridge resistors R1 and R4 of the right sensor half 4 are located in the edge area of the measuring membrane 2 near the mechanical fastening and the bridge resistors R2 and R3 are located in the center of the measuring membrane 2.
  • the bridge resistances R2 and R3 in the center of the measuring membrane 2 to expand in the same direction due to the radial mechanical stress, which leads to an increase in their resistance values (+ ⁇ R).
  • the bridge resistors R2 and R4 in the edge area compression occurs due to the opposite curvature in the fastening area of the measuring membrane 2. Also due to the radial mechanical stress, this leads to a reduction in the resistance values (- ⁇ R) the bridge resistors Rl and R4.
  • the resulting detuning of the measuring bridge 8 can be evaluated via the changed bridge diagonal voltage Umr.
  • the bridge resistances R1 and R4 are arranged identically to the corresponding bridge resistances R1 and R4 in the right half of the sensor 4 and therefore also experience the same changes in resistance.
  • the bridge resistances R2 and R3 of the measuring bridge 7 are also arranged in the edge region of the pressure measuring membrane 2 in such a way that a tangential expansion effect of the membrane surface due to the mechanical tension is evaluated here.
  • the meandering resistance tracks 9 of the resistors R2 and R3 also experience an increase in resistance (+ ⁇ R) due to expansion, but the mechanical interactions between a pressure change (+ ⁇ p) and the detuning of the bridge diagonal voltage Uml are lower different from the interactions on the right sensor half 4.
  • the bridge resistances R2 and R3 of the left-hand measuring bridge 7 also lie in a region of the measuring membrane 2 that is relatively free from mechanical stress, so that the reliability of the left-hand measuring bridge 7 is very high and the emergency running properties of the sensor 1 are also improved.
  • the diagram according to FIG. 5 shows schematically some typical courses of the mechanical stress ⁇ over the radius of the measuring membrane 2 and the resulting expansions / compressions ⁇ on the bridge resistances R1 to R4.
  • Curve 10 shows the course of the radially acting tension ⁇ r and curve 11 shows the course of the tangentially acting tension ⁇ t.
  • Curve 12 represents the course of radial expansion ⁇ r and curve 13 represents the course of tangential expansion ⁇ t with reference to the right vertical coordinate axis.
  • the tangential stress ⁇ t (curve 11) and the resulting elongation ⁇ t are essentially flatter and therefore have another dependency on the pressure change ⁇ p.
  • the bridge resistances R2 and R3 of the left sensor half 3 can be placed in an area of the measuring membrane 2 in which a strain comparable to that of the bridge resistances R2 and R3 right sensor half 4 is detected.
  • the cheapest arrangement possibilities of the bridge branches are indicated in the diagram according to FIG. 5 by small circles, which are approximately symmetrical (+ ⁇ l; - ⁇ l) to the zero point of the expansion-compression axis ⁇ .

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

A testable and highly available sensor has a measurement membrane that bears the resistances of two different full bridges. On the right half (4) radial compressions (R1, 4) and extensions (R2, 3) are used, on the left half (3) radial compressions (R1, 4) but tangential extensions (R2, 3) are used. Ageing phenomena influence the sensitivity of both full bridges to a different extent, so that the sensor may be tested during its operation without any special reference measurements. In addition, one full bridge may be used in an emergency when the other full bridge breaks down.

Description

Prüfbarer Membransensor mit zwei Vollbrücken Testable membrane sensor with two full bridges
Stand der TechnikState of the art
Die Erfindung betrifft einen Sensor, insbesondere einen Druckεensor nach der Gattung des Hauptanspruchs.The invention relates to a sensor, in particular a pressure sensor according to the preamble of the main claim.
Es εind beiεpielsweise Drucksenεoren bekannt, bei denen auf einer Meßmembran Dünnschicht-Widerstandsmeßbrücken zur Meε- εung von absoluten Drücken oder von Druckänderungen inεbe¬ sondere in hydraulischen Systemen angeordnet sind. Bewegun¬ gen der Meßmembran aufgrund von Druckschwankungen führen hierbei aufgrund von Stauchungen oder Streckungen der in der Regel mäanderförmigen Widerstandsbahnen zu Widerεtandε- änderungen in den jeweiligen Dünnschichtwiderständen. Die Dünnschichtwiderεtände εind hierbei in bekannter Weiεe zu einer Wheatεton-Meßbrücke verschaltet, wobei die Zuordnung der Dünnεchichtwiderstände zu den Brückenzweigen bzw. zu den Bereichen auf der Drucksenεormembran εo gewählt iεt, daß sich die gegenüberliegenden Widerstände jeweilε gleich¬ sinnig ändern und eine Brücken-Diagonalspannung alε Senεor- εignal meßbar iεt. In den häufigεten Anwendungεfallen für Drucksenεoren, bei¬ εpielsweiεe in hydrauliεchen Bremεsystemen in Kraftfahrzeu¬ gen, muß ein genaues Ausgangεεignal entsprechend dem Druck der Bremεhydraulik ( Meßbereich ca. 250 bar ) hochzuverläε- sig und möglichst auch ausfallsicher erzeugbar sein. Inεbe- εondere bei εicherheitεkritiεchen Syεtemen im Bereich der Bremsanlagen, z. B. im Antiblockiersystem oder bei der An- tiεchlupfregelung, werden Senεoren benötigt, deren einwand¬ freie Funktion auch ständig überprüfbar εein muß. Weitere Anwendungεfalle εind Überwachungsfunktionen in pneumati¬ schen Syεtemen sowie bei Einspritzanlagen für die Kraft¬ stoffzufuhr in Kraftfahrzeugen.Pressure sensors are known, for example, in which thin-film resistance measuring bridges for measuring absolute pressures or pressure changes, in particular in hydraulic systems, are arranged on a measuring membrane. Movements of the measuring membrane due to pressure fluctuations lead here to changes in resistance in the respective thin-film resistors due to compression or stretching of the generally meandering resistance tracks. The thin-film resistors are connected in a known manner to form a Wheatεton measuring bridge, the assignment of the thin-film resistors to the bridge branches or to the areas on the pressure sensor membrane being chosen such that the opposing resistances change in the same sense and a bridge diagonal voltage is al Sensor signal is measurable. In the most common application cases for pressure sensors, for example in hydraulic brake systems in motor vehicles, an accurate output signal corresponding to the pressure of the brake hydraulics (measuring range approx. 250 bar) must be highly reliable and, if possible, also fail-safe. In particular, in the case of safety-critical systems in the area of brake systems, e.g. B. in the anti-lock braking system or in anti-slip control, sensors are required, the proper functioning of which must also be continuously verifiable. Further applications are monitoring functions in pneumatic systems and in injection systems for the fuel supply in motor vehicles.
Es iεt weiterhin bekannt, daß die Überwachung von Drucksen¬ εoren, die Widerstandsmeßbrücken aufweisen, dadurch vorge¬ nommen wird, daß in vorgegebenen zeitlichen Abständen eine absolute Meεεung der Einzelwiderεtände vorgenommen wird um εomit z. B. alterungs- oder zerstörungsbedingte (z. B. Kor¬ rosion oder Bruch) Änderungen der Widerεtandseigenschaften der einzelnen Dünnεchichtwiderεtände zu erkennen. Auch pla¬ stische Verformungen der Druckmeßmembran durch Überdruck oder Reißen an der am höchsten belasteten Stelle in der Mitte der Membran führen zu Fehlmesεungen. Eine Änderung von sich gleichsinnig ändernden Widerständen in den Brük- kenzweigen kann hierbei ohne die bereit erwähnten besonde¬ ren Maßnahmen nicht erkannt werden, da diese Änderungen εich in der Meßbrücke im Offset kompensieren und damit die Meßbrücke nasch außen scheinbar unverändert ist, die Emp¬ findlichkeit sich aber ändert und damit zu Fehlern führt.It is also known that the monitoring of pressure sensors which have resistance measuring bridges is carried out in that an absolute measurement of the individual resistances is carried out at predetermined time intervals in order to measure z. B. aging or destruction-related (z. B. corrosion or break) changes in the resistance properties of the individual thin-film resistances. Plastic deformations of the pressure measuring membrane due to overpressure or tearing at the most stressed point in the middle of the membrane also lead to incorrect measurements. A change of resistances in the bridge branches which change in the same direction cannot be recognized here without the special measures already mentioned, since these changes are offset in the measuring bridge in offset and the measuring bridge is thus apparently unchanged from the outside, the sensitivity but changes and thus leads to errors.
Die sich jeweils gleichsinnig ändernden Widerstände der Meßbrücke befinden εich auf der Druckmeßmembran vorzugεwei¬ εe an Orten mit den gleichen mechaniεchen Eigenschaften be¬ züglich Zug-/Druckdehnung (entweder in der Mitte oder am Rand der Druckmeßmembran) und werden deεhalb gleich bela- εtet; entεprechend verhalten εich ihre Abweichungen. Auch plastische Verformungen der Druckmeßmembran zeigen somit die gleichen, nicht erkennbaren Signalfehler. Eine weitere bekannte Möglichkeit der Erkennung solcher Fehler iεt der in bestimmten Abständen wiederholte Vergleich der Einzelwi- derεtände mit einem εtabilen Referenzwiderεtand. Der über die geεamte Lebensdauer εtabile Referenzwiderstand kann hierbei zu einem Brückenwiderstand parallel geschaltet wer¬ den und daher zur Überwachung von Änderungen deε Brücken- Auεgangεεignalε herangezogen werden.The resistances of the measuring bridge, which change in the same direction, are preferably located on the pressure measuring membrane at locations with the same mechanical properties with regard to tensile / compressive strain (either in the middle or on Edge of the pressure measuring membrane) and are therefore loaded equally; their deviations behave accordingly. Plastic deformations of the pressure measuring membrane also show the same, undetectable signal errors. Another known possibility of recognizing such errors is to compare the individual resistances, which are repeated at certain intervals, with a stable reference resistor. The reference resistor, which is stable over the entire service life, can be connected in parallel to a bridge resistor and can therefore be used to monitor changes in the bridge output signal.
Die bekannten Senεoren mit den beεonderen Überwachungsme- chanismen haben vor allem den Nachteil, daß ständig zwi¬ schen dem Prüf- /Überwachungsmoduε und der Drucksensierung umgeεchaltet werden muß, waε die Dynamik deε Senεors stark herabsetzt, da die Referenzmeεεung Zeit erfordert. Ferner können hiermit Forderungen nach Auεfallεicherheit und Red¬ undanz nicht realiεiert werden.The known sensors with the special monitoring mechanisms have the particular disadvantage that there must be a constant switch between the test / monitoring module and the pressure sensor, since the dynamics of the sensor are greatly reduced since the reference measurement takes time. Furthermore, demands for reliability and redundancy cannot be met in this way.
Vorteile der ErfindungAdvantages of the invention
Der erfindungεgemäße Sensor der eingangs angegebenen Art ist mit den kennzeichnenden Merkmalen des Anspruchε 1 inε¬ beεondere dadurch vorteilhaft, daß durch die Anordnung von zwei voneinander unabhängigen Widerεtandεmeßbrücken auf je¬ weils einer Membranhälfte eine Überprüfung der Funktionsfä¬ higkeit deε Senεorε während deε Betriebeε ohne beεondere Referenzmessungen erfolgen kann. Zusätzlich erhöht sich die Verfügbarkeit des Sensorε, da auch bei Auεfall einer Wider- εtandεmeßbrücke ein Notlauf deε Systemε mit der anderen Meßbrücke gewährleistet ist. - Λ -The sensor according to the invention of the type specified at the outset is particularly advantageous with the characterizing features of claim 1 in that, by arranging two mutually independent resistance measuring bridges on each membrane half, a check of the functionality of the sensor during operation without particular reference measurements can be done. In addition, the availability of the sensor increases, since even if one of the resistance measuring bridges fails, an emergency operation of the system with the other measuring bridge is guaranteed. - Λ -
Bei einer bevorzugten Ausführungsform des erfindungsgemäßen Sensors sind die Dünnschichtwiderstände zumindest einer der beiden Widerεtandsmeßbrücken εo auf der Meßmembran angeord¬ net, daß radiale Dehnungen/Stauchungen der Meßmembran zu Widerεtandεerhöhung bzw. -Verringerung führen. Bei der je¬ weilε anderen Widerεtandεmeßbrücke εind die εich in der Brücke gegenüberliegenden Dünnschichtwiderεtände auf der Meßmembran εo angeordnet, daß vorzugεweise im Randbereich der Membran eine tangentiale Dehnung erfaßt wird und diese zu der Widerstandserhöhung führt. Durch die Ausnutzung des Tangentialeffekts werden diesen Widerstände εchwächer bela- εtet und die Abweichung über die Lebenεdauer εind εomit auch niedriger.In a preferred embodiment of the sensor according to the invention, the thin-film resistors of at least one of the two resistance measuring bridges are arranged on the measuring membrane such that radial expansions / compressions of the measuring membrane lead to an increase or decrease in resistance. In the case of the other resistance measuring bridge, the thin-film resistances opposite each other in the bridge are arranged on the measuring membrane in such a way that a tangential strain is detected in the edge area of the membrane and this leads to an increase in resistance. By utilizing the tangential effect, these resistances are less stressed and the deviation over the lifetime is thus also lower.
Da die beiden Meßbrücken gemäß der vorgehend beεchriebenen Auεführungεform εich hinεichtlich deε Brückendiagonalεi- gnalε über der Lebensdauer unterεchiedlich verhalten, da die Dünnεchichtwiderεtände zur Erfassung der tangentialen Dehnung eine andere Membranbewegung erfassen als die radia¬ le Dehnung oder Stauchung, kann durch Vergleich der beiden Brückensignale eine einfach Funktionsüberprüfung erfolgen. Auch plastiεche Verformungen der Druckmeßmembran können εo eindeutig im Brückenoffset erkannt werden, da die beiden Brücken-Diagonalεignale hierdurch deutlich auεeinander driften. Alterungserscheinungen sowie mechanische oder phy- sikaliεch-chemische Effekte beeinflusεen die Empfindlich¬ keit der beiden Brücken unterschiedlich, εo daß diese durch einen Vergleich erkannt werden können.Since the two measuring bridges behave differently over the service life with regard to the bridge diagonal signal according to the above-described embodiment, since the thin-film resistances for detecting the tangential expansion detect a different membrane movement than the radial expansion or compression, a simple comparison can be made by comparing the two bridge signals Functional check done. Plastic deformations of the pressure measuring membrane can also be clearly identified in the bridge offset, since the two bridge diagonal signals thereby drift clearly apart. Signs of aging as well as mechanical or physical-chemical effects influence the sensitivity of the two bridges differently, so that they can be identified by comparison.
Weitere vorteilhafte Auεführungεformen εind in den Unteran- εprüchen angegeben.Further advantageous embodiments are specified in the subclaims.
Zeichnung Ein Ausführungsbeiεpiel deε erfindungsgemäßen Sensors wird anhand der Zeichnung erläutert. Es zeigen:drawing An exemplary embodiment of the sensor according to the invention is explained on the basis of the drawing. Show it:
Figur 1 eine Draufsicht auf eine Meßmembran eineε Drucksensorε;FIG. 1 shows a plan view of a measuring membrane of a pressure sensor;
Figur 2 ein elektrisches Schaltbild der rechten Me߬ brücke;FIG. 2 shows an electrical circuit diagram of the right measuring bridge;
Figur 3 ein elektrisches Schaltbild der linken Me߬ brücke;FIG. 3 shows an electrical circuit diagram of the left measuring bridge;
Figur 4 ein Detailbild eins Dünnschichtwiderεtandeε undFIG. 4 shows a detailed image of a thin-film resistor and
Figur 5 ein Diagramm der mechaniεchen Spannung / Deh¬ nungen auf der Meßmembran.Figure 5 is a diagram of the mechanical stresses / strains on the measuring membrane.
Beschreibung deε AuεführungsbeispielεDescription of the exemplary embodiment
In der Figur 1 ist ein Senεor 1 dargestellt, der als Druck- εenεor für die Erfaεεung der Druckverhältnisse in der Bremshydraulik eines Kraftfahrzeuges dient. Der Senεor 1 enthält eine Meßmembran 2 (beiεpielsweise aus Metall) auf der Dünnschichtwiderεtände Rl, R2, R3 und R4 (beiεpielε¬ weiεe auε polykristallinem Silizium) auf jeder von zwei Senεorhälften 3 und 4 aufgebracht sind. Die Dünnschichtwi¬ derεtände Rl biε R4 εind auf dem Meßmembran 2 an Punkten 5 kontaktiert und für die äußere Verbindung εind die Punkte 5 jeweils an Kontaktpads 6 herangeführt. Dieε iεt in der Fi¬ gur 1 der besseren Übersicht wegen nur beispielsweiεe am Widerstand Rl der rechten Sensorhälfte 4 dargestellt.FIG. 1 shows a sensor 1 which serves as a pressure sensor for detecting the pressure conditions in the brake hydraulics of a motor vehicle. The sensor 1 contains a measuring membrane 2 (for example made of metal) on which thin-film resistors R1, R2, R3 and R4 (for example made of polycrystalline silicon) are applied to each of two sensor halves 3 and 4. The thin-film resistors R1 to R4 are contacted on the measuring membrane 2 at points 5 and for the external connection, the points 5 are each brought into contact pads 6. This is shown in FIG. 1 for the sake of a better overview only because of the resistance R1 of the right sensor half 4, for example.
Figur 2 und Figur 3 zeigen die elektriεchen Ersatzschalt¬ bilder der Widerstände Rl bis R4 auf der Sensorhälfte 3 (Figur 2) und der Sensorhälfte 4 (Figur 3) , die jeweils ei¬ ne Wheatston-Meßbrücke 7 bzw. 8 bilden. Zur Auswertung alε Senεorauεgangεεignal εtehen die Brücken-Diagonalεpannungen Uml (Figur 2) um Umr (Figur 3) zur Verfügung.FIG. 2 and FIG. 3 show the electrical equivalent circuit diagrams of the resistors R1 to R4 on the sensor half 3 (FIG. 2) and the sensor half 4 (FIG. 3), which each form a Wheatstone measuring bridge 7 and 8, respectively. For evaluation as The sensor diagonal voltages Um1 (FIG. 2) by Umr (FIG. 3) are available for the sensor output signal.
Ein Auεführungεbeispiel eines der Dünnschichtwiderεtände Rl biε R4 zeigt Figur 4, in der die mäanderförmige Struktur von Widerεtandsbahnen 9 zwischen den Punkten 5 erkennbar ist. Die Widerstände Rl bis R4 erfahren hierbei eine Ände¬ rung ihres Widerstandεwerteε (+ΔR) bei einer Dehnung (+Δl) in der dargestellten Richtung. Bei Widerständen aus anderen Materialien kann auch ein anderer geometrischer Aufbau zur Erreichung des gleichen Meßeffektes gewählt werden.FIG. 4 shows an exemplary embodiment of one of the thin-film resistors R1 to R4, in which the meandering structure of resistance paths 9 between points 5 can be seen. The resistors R1 to R4 experience a change in their resistance value (+ ΔR) with an elongation (+ Δl) in the direction shown. In the case of resistors made of other materials, a different geometrical structure can also be selected to achieve the same measurement effect.
In Figur 5 ist ein Diagramm der Verläufe der durch Druckän¬ derungen verurεachten mechaniεchen Spannungen σ und der daraus resultierenden Dehnungen bzw. Stauchungen ε in radi¬ al unterschiedlichen Bereichen der Meßmembran 2 gezeigt. Eine Erläuterung dieεeε Diagrammε erfolgt anhand der Be- εchreibung des Ausführungsbeispielε, insbesondere mit Bezug auf die Figuren 1 bis 3.FIG. 5 shows a diagram of the courses of the mechanical stresses σ caused by pressure changes and the resulting strains or compressions ε in radially different areas of the measuring membrane 2. An explanation of this diagram is given using the description of the exemplary embodiment, in particular with reference to FIGS. 1 to 3.
Die Brückenwiderstände Rl und R4 der rechten Sensorhälfte 4 (vgl. Figur 1 und 3) befinden sich im Randbereich der Me߬ membran 2 in der Nähe der mechanischen Befestigung und die Brückenwiderstände R2 und R3 befinden εich im Zentrum der Meßmembran 2. Bei einer Auslenkung bzw. Verwölbung der Me߬ membran 2 durch eine Druckerhöhung erfahren die Brückenwi¬ derstände R2 und R3 im Zentrum der Meßmembran 2 eine gleichsinnige Dehnung aufgrund der radial wirkenden mecha¬ nischen Spannung, was zu einer Erhöhung ihrer Widerstands- werte (+ΔR) führt. Bei den Brückenwiderständen R2 und R4 im Randbereich erfolgt eine Stauchung durch die gegensinnige Verwölbung im Befestigungsbereich der Meßmembran 2. Eben¬ falls aufgrund der radial wirkenden mechanischen Spannung führt dieε zu einer Verringerung der Widerstandswerte (-ΔR) der Brückenwiderεtände Rl und R4. Die dadurch erfolgte Ver¬ stimmung der Meßbrücke 8 kann über die veränderte Brücken- DiagonalSpannung Umr ausgewertet werden.The bridge resistors R1 and R4 of the right sensor half 4 (see FIGS. 1 and 3) are located in the edge area of the measuring membrane 2 near the mechanical fastening and the bridge resistors R2 and R3 are located in the center of the measuring membrane 2. In the event of a deflection or Warping of the measuring membrane 2 due to an increase in pressure causes the bridge resistances R2 and R3 in the center of the measuring membrane 2 to expand in the same direction due to the radial mechanical stress, which leads to an increase in their resistance values (+ ΔR). In the case of bridge resistors R2 and R4 in the edge area, compression occurs due to the opposite curvature in the fastening area of the measuring membrane 2. Also due to the radial mechanical stress, this leads to a reduction in the resistance values (-ΔR) the bridge resistors Rl and R4. The resulting detuning of the measuring bridge 8 can be evaluated via the changed bridge diagonal voltage Umr.
In der linken Sensorhälfte 3 sind die Brückenwiderstände Rl und R4 (vgl. Figur 1 und 2) identisch zu den entsprechenden Brückenwiderεtänden Rl und R4 in der rechten Senεorhälfte 4 angeordnet und erfahren daher auch die gleiche Widerstandε- änderungen. Zur Schaffung der in der Beεchreibungεeinlei- tung angeführten vorteilhaften Eigenεchaften εind jedoch die Brückenwiderεtände R2 und R3 der Meßbrücke 7 ebenfallε im Randbereich der Druckmeßmembran 2 angeordnet und zwar derart, daß hier ein tangentialer Dehnungseffekt der Mem¬ branoberfläche aufgrund der mechanischen Spannung ausgewer¬ tet wird. Die mäanderförmigen Widerstandsbahnen 9 der Wi¬ derstände R2 und R3 erfahren hier zwar auch eine Wider¬ standserhöhung(+ΔR) durch Dehnung, jedoch sind die mechani¬ schen Wechselwirkungen zwischen einer Druckänderung (+Δp) und der Verstimmung der Brücken-Diagonalspannung Uml unter¬ schiedlich zu den Wechselwirkungen auf der rechten Sensor¬ hälfte 4.In the left half of the sensor 3, the bridge resistances R1 and R4 (see FIGS. 1 and 2) are arranged identically to the corresponding bridge resistances R1 and R4 in the right half of the sensor 4 and therefore also experience the same changes in resistance. To create the advantageous properties listed in the introduction, however, the bridge resistances R2 and R3 of the measuring bridge 7 are also arranged in the edge region of the pressure measuring membrane 2 in such a way that a tangential expansion effect of the membrane surface due to the mechanical tension is evaluated here. The meandering resistance tracks 9 of the resistors R2 and R3 also experience an increase in resistance (+ ΔR) due to expansion, but the mechanical interactions between a pressure change (+ Δp) and the detuning of the bridge diagonal voltage Uml are lower different from the interactions on the right sensor half 4.
Aufgrund der unterεchiedlichen Auεwertungen einer Druckän¬ derung (Δp) in den beiden Senεorhälften 3 und 4 können εo¬ mit eine Vielzahl von Fehlern im Senεor 1 (beiεpielεweiεe durch Alterung, Korroεion oder Membranbruch) , die anεonsten zu gleichsinnigen Änderungen der Brückenwiderstände führen und sich damit im Brücken-Offset kompensieren würden, er¬ kannt werden. Die Brückenwiderstände R2 und R3 der linken Meßbrücke 7 liegen außerdem in einem mechanischen relativ wenig beanspruchten Bereich der Meßmembran 2, so daß die Zuverläεεigkeit der linken Meßbrücke 7 sehr hoch ist und damit auch die Notlaufeigenschaften deε Senεorε 1 verbes¬ sert sind. Daε Diagramm nach Figur 5 zeigt εchematiεch einige typiεche Verläufe der mechaniεchen Spannung σ über dem Radiuε r der Meßmembran 2 und der darauε reεultierenden Dehnungen / Stauchungen ε an den Brückenwiderεtänden Rl biε R4. In der Kurve 10 iεt der Verlauf der radial wirkenden Spannung σr und in der Kurve 11 iεt der Verlauf der tangential wirken¬ den Spannung σt gezeigt. Die Kurve 12 εtellt den Verlauf der radialen Dehnung εr und die Kurve 13 den Verlauf der tangentialen Dehnung εt mit Bezug zur rechten vertikalen Koordinatenachεe dar.Due to the different evaluations of a pressure change (Δp) in the two sensor halves 3 and 4, a large number of errors in sensor 1 (for example due to aging, corrosion or membrane breakage) can otherwise lead to changes in the bridge resistances in the same direction and thus would compensate in the bridge offset. The bridge resistances R2 and R3 of the left-hand measuring bridge 7 also lie in a region of the measuring membrane 2 that is relatively free from mechanical stress, so that the reliability of the left-hand measuring bridge 7 is very high and the emergency running properties of the sensor 1 are also improved. The diagram according to FIG. 5 shows schematically some typical courses of the mechanical stress σ over the radius of the measuring membrane 2 and the resulting expansions / compressions ε on the bridge resistances R1 to R4. Curve 10 shows the course of the radially acting tension σr and curve 11 shows the course of the tangentially acting tension σt. Curve 12 represents the course of radial expansion εr and curve 13 represents the course of tangential expansion εt with reference to the right vertical coordinate axis.
Auε der Kurve 12 der Figur 5 iεt deutlich der Übergang von der εtarken Dehnung im Zentrum der Meßmembran 2 (r=0) zur Stauchung im Randbereich zu erkennen, hervorgerufen durch die radiale Spannung εr (Kurve 10) , die auε einer Drucker¬ höhung Δp reεultiert. Die tangentiale Spannung σt (Kurve 11) und die darauε reεultierende Dehnung εt verläuft dage¬ gen weεentlich flacher und besitzt daher eine andere Abhän¬ gigkeit von der Druckänderung Δp. Um jedoch nahezu gleiche Meßbereiche bei der normalen Auswertung der Brücken- Diagonalεpannungen zu erhalten, können die Brückenwider¬ εtände R2 und R3 der linken Senεorhälfte 3 in einen Bereich der Meßmembran 2 gelegt werden, in dem eine vergleichbare Dehnung wie an den Brückenwiderεtänden R2 und R3 der rech¬ ten Senεorhälfte 4 detektiert wird. Die günstigsten Anord¬ nungsmöglichkeiten der Brückenzweige sind im Diagramm nach Figur 5 durch kleine Kreise angedeutet, die in etwa symme¬ trisch(+εl;-εl) zum Nullpunkt der Dehnungs -Stauchungsachse ε liegen. The curve 12 in FIG. 5 clearly shows the transition from the strong elongation in the center of the measuring membrane 2 (r = 0) to the compression in the edge region, caused by the radial stress εr (curve 10) which results from a pressure increase Δp results. The tangential stress σt (curve 11) and the resulting elongation εt, on the other hand, are essentially flatter and therefore have another dependency on the pressure change Δp. However, in order to obtain almost the same measuring ranges in the normal evaluation of the bridge diagonal voltages, the bridge resistances R2 and R3 of the left sensor half 3 can be placed in an area of the measuring membrane 2 in which a strain comparable to that of the bridge resistances R2 and R3 right sensor half 4 is detected. The cheapest arrangement possibilities of the bridge branches are indicated in the diagram according to FIG. 5 by small circles, which are approximately symmetrical (+ εl; -εl) to the zero point of the expansion-compression axis ε.

Claims

Patentanεprüche Claims
1) Senεor,1) sensor,
- mit einem Meßelement auf einer Meßmembran (2) , bestehend aus mindestenε einer Widerstands-Meßbrücke (7,8), wobei sich durch eine Auslenkung der Meßmembran (2) eine Verεtim- mung der jeweiligen Meßbrücke (7,8) ergibt und die darauε reεultierende Änderung der Brücken-Diagonalεpannung aus¬ wertbar iεt, wobei der Senεor (1) jeweils eine Widerεtandε- Meßbrücke (7,8) auf jeweilε einer Hälfte (3,4) der Meßmem¬ bran (2) aufweiεt, dadurch gekennzeichnet, daß- With a measuring element on a measuring membrane (2), consisting of at least one resistance measuring bridge (7,8), whereby a deflection of the measuring membrane (2) results in a detuning of the respective measuring bridge (7,8) and this Resulting change in the bridge diagonal voltage can be evaluated, the sensor (1) each having a resistance measuring bridge (7,8) on each half (3,4) of the measuring membrane (2), characterized in that
- in einer erεten Widerεtandε-Meßbrücke (8) alle vier Brük- kenzweige (R1,R2,R3,R4) mit radial wirkenden mechaniεchen Spannungen (σr) auf der Meßmembran (2) beaufεchlagt werden, wobei diese durch radiale Dehnung beanspruchten Brücken¬ zweige im Zentrum der Meßmembran (2) liegen und daß- In a first resistance measuring bridge (8), all four bridge branches (R1, R2, R3, R4) are acted upon by radially acting mechanical stresses (σr) on the measuring membrane (2), these bridge branches being stressed by radial expansion are in the center of the measuring membrane (2) and that
- in der zweiten Widerstands-Meßbrücke (7) , abweichend von der ersten, die Brückenzweige (R2,R3) die mit einer tangen¬ tialen Dehnung beaufschlagt werden, im Randbereich der Me߬ membran (2) liegen und so ausgerichtet sind, daß auf sie tangentiale mechaniεche Spannungen(σt) einwirken. - In the second resistance measuring bridge (7), deviating from the first, the bridge branches (R2, R3) which are subjected to a tangential expansion, lie in the edge region of the measuring membrane (2) and are oriented so that on they act on tangential mechanical stresses (σt).
EP96922746A 1995-07-28 1996-07-06 Testable membrane sensor with two full bridges Ceased EP0783677A1 (en)

Applications Claiming Priority (3)

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DE19527687A DE19527687A1 (en) 1995-07-28 1995-07-28 sensor
DE19527687 1995-07-28
PCT/DE1996/001211 WO1997005464A1 (en) 1995-07-28 1996-07-06 Testable membrane sensor with two full bridges

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JP (1) JPH10506718A (en)
DE (1) DE19527687A1 (en)
WO (1) WO1997005464A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1068055C (en) * 1996-03-05 2001-07-04 奥地利钢铁联合企业阿尔帕工业设备制造公司 Process for production of liquid pig iron or liquid intermediate products of liquid steel and spongy metal
DE10203631B4 (en) * 2001-01-31 2009-11-19 DENSO CORPORATION, Kariya-shi Semiconductor sensor for a dynamic size

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6142021A (en) * 1998-08-21 2000-11-07 Motorola, Inc. Selectable pressure sensor
JP4438193B2 (en) * 1999-09-24 2010-03-24 株式会社デンソー Pressure sensor
JP4062858B2 (en) * 2000-04-27 2008-03-19 株式会社デンソー Pressure sensor
US6422088B1 (en) 1999-09-24 2002-07-23 Denso Corporation Sensor failure or abnormality detecting system incorporated in a physical or dynamic quantity detecting apparatus
US6518880B2 (en) 2000-06-28 2003-02-11 Denso Corporation Physical-quantity detection sensor
JP2002298279A (en) * 2001-01-26 2002-10-11 Texas Instruments Inc State response detection system and method
DE102004013073A1 (en) * 2004-03-11 2005-09-29 Ab Elektronik Sachsen Gmbh Production method, e.g. for pressure measuring elements, involves having plate-shaped body with several holes being set distance from each other and body thinned by holes
FR2883372B1 (en) * 2005-03-17 2007-06-29 Commissariat Energie Atomique FORCE MEASURING DEVICE BY RESISTIVE DETECTION WITH DOUBLE BRIDGE OF WHEASTONE
JP2008039760A (en) * 2006-07-14 2008-02-21 Denso Corp Pressure sensor
DE102008041772A1 (en) 2008-09-02 2010-03-04 Tecsis Gmbh Deformation-detecting measuring device for physical values has weld seam all round metal carrier and penetrating right through metal body-carrier joint
DE102008041771B4 (en) 2008-09-02 2018-05-03 Tecsis Gmbh Measuring device with tunable resistance
CN202158916U (en) * 2009-09-30 2012-03-07 泰科思有限责任公司 Measuring device for deformation detection
DE102010042536B4 (en) * 2010-10-15 2020-07-16 Ifm Electronic Gmbh Diagnostic resistive pressure measuring cell
DE102010035862B4 (en) * 2010-08-30 2013-01-03 Ifm Electronic Gmbh Diagnostic resistive pressure cell
US20130118264A1 (en) 2010-08-30 2013-05-16 Ifm Electronic Gmbh Resistive pressure measuring cell having diagnostic capabilities
DE102011084972B4 (en) * 2010-11-04 2015-07-16 Ifm Electronic Gmbh Method for correcting measured values of a pressure measuring cell whose membrane has undergone a plastic deformation due to an increased pressure load
DE102011080229B4 (en) 2011-08-01 2017-07-27 Ifm Electronic Gmbh Method for checking the function of a pressure sensor
US9714876B2 (en) * 2015-03-26 2017-07-25 Sensata Technologies, Inc. Semiconductor strain gauge
JP7114032B2 (en) * 2018-09-26 2022-08-08 ユニパルス株式会社 load transducer
US11092504B2 (en) 2019-05-21 2021-08-17 Rosemount Aerospace Inc. Micromechanical redundant piezoresistive array pressure sensor
FR3098298B1 (en) * 2019-07-03 2021-07-16 Arianegroup Sas Dual pressure sensor
JP7294009B2 (en) * 2019-09-09 2023-06-20 Tdk株式会社 pressure sensor
US11885704B2 (en) 2020-07-27 2024-01-30 Precision Biomems Corporation Flexible two-dimensional sheet array of electronic sensor devices
US11650110B2 (en) * 2020-11-04 2023-05-16 Honeywell International Inc. Rosette piezo-resistive gauge circuit for thermally compensated measurement of full stress tensor
CN114323354B (en) * 2021-12-08 2023-11-03 中国电子产品可靠性与环境试验研究所（（工业和信息化部电子第五研究所）（中国赛宝实验室）） Compensation method and device for pressure transmitter and computer equipment

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3358511A (en) * 1965-10-05 1967-12-19 Electro Optical Systems Inc Computing transducer system
JPS59217375A (en) * 1983-05-26 1984-12-07 Toyota Central Res & Dev Lab Inc Semiconductor mechanic-electric conversion device
US4565097A (en) * 1984-05-09 1986-01-21 Mark Telephone Products, Inc. Method and apparatus for transducer error cancellation
US4528855A (en) * 1984-07-02 1985-07-16 Itt Corporation Integral differential and static pressure transducer
DE3538091A1 (en) * 1985-10-25 1987-04-30 Npsk Poluprovodnikova Technika DEVICE FOR COORDINATE POSITIONING
DE3705901C2 (en) * 1987-02-24 1996-12-12 Siemens Ag Pressure transducer
JPH0337503A (en) * 1989-07-03 1991-02-18 Kayaba Ind Co Ltd Strain gage
JPH0337537A (en) * 1989-07-04 1991-02-18 Kayaba Ind Co Ltd Pressure sensor
JPH0342539A (en) * 1989-07-11 1991-02-22 Kayaba Ind Co Ltd Pressure sensor
DE4000326C2 (en) * 1990-01-08 1995-12-14 Mannesmann Ag Pressure sensor
JPH0472772A (en) * 1990-07-13 1992-03-06 Mitsubishi Electric Corp Semiconductor pressure sensor
JPH0582805A (en) * 1991-09-19 1993-04-02 Mitsubishi Electric Corp Pressure detecting chip of semiconductor pressure detector
US5291788A (en) * 1991-09-24 1994-03-08 Kabushiki Kaisha Toshiba Semiconductor pressure sensor
US5349867A (en) * 1991-12-02 1994-09-27 Kavlico Corporation Sensitive resistive pressure transducer
JP2816635B2 (en) * 1993-01-14 1998-10-27 株式会社山武 Semiconductor pressure sensor
DE4335700A1 (en) * 1993-10-20 1995-04-27 Bosch Gmbh Robert Method and device for monitoring the function of a sensor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9705464A1 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1068055C (en) * 1996-03-05 2001-07-04 奥地利钢铁联合企业阿尔帕工业设备制造公司 Process for production of liquid pig iron or liquid intermediate products of liquid steel and spongy metal
DE10203631B4 (en) * 2001-01-31 2009-11-19 DENSO CORPORATION, Kariya-shi Semiconductor sensor for a dynamic size

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US6289738B1 (en) 2001-09-18
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JPH10506718A (en) 1998-06-30

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