WO2007017383A1 - Procede et dispositif pour faire fonctionner un capteur d'etat destine a des liquides - Google Patents

Procede et dispositif pour faire fonctionner un capteur d'etat destine a des liquides Download PDF

Info

Publication number
WO2007017383A1
WO2007017383A1 PCT/EP2006/064683 EP2006064683W WO2007017383A1 WO 2007017383 A1 WO2007017383 A1 WO 2007017383A1 EP 2006064683 W EP2006064683 W EP 2006064683W WO 2007017383 A1 WO2007017383 A1 WO 2007017383A1
Authority
WO
WIPO (PCT)
Prior art keywords
sensor
determined
values
amplitude
voltage levels
Prior art date
Application number
PCT/EP2006/064683
Other languages
German (de)
English (en)
Inventor
Markus Gilch
Stephan Heinrich
Original Assignee
Siemens Vdo Automotive Ag
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 Siemens Vdo Automotive Ag filed Critical Siemens Vdo Automotive Ag
Priority to EP06792574A priority Critical patent/EP1913361A1/fr
Publication of WO2007017383A1 publication Critical patent/WO2007017383A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
    • G01N11/10—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material
    • G01N11/16—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material by measuring damping effect upon oscillatory body
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/02—Analysing fluids
    • G01N29/032—Analysing fluids by measuring attenuation of acoustic waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/02—Analysing fluids
    • G01N29/036—Analysing fluids by measuring frequency or resonance of acoustic waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/34—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor
    • G01N29/346—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor with amplitude characteristics, e.g. modulated signal
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/26—Oils; Viscous liquids; Paints; Inks
    • G01N33/28—Oils, i.e. hydrocarbon liquids
    • G01N33/2888—Lubricating oil characteristics, e.g. deterioration
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/028—Material parameters
    • G01N2291/02818—Density, viscosity

Definitions

  • the present invention relates to a method and apparatus for operating a condition sensor for liquids.
  • Engine oil by the intake of dirt over a period of operation strongly from.
  • the contamination can come from soot particles, but also from metallic abrasion of cylinder surfaces, etc. ago.
  • it is therefore necessary to carry out maintenance at regular maintenance intervals and mileage intervals of approximately 15,000 km, during which the engine oil is exchanged with associated filter devices.
  • the deterioration of the quality in the engine oil does not run the same for all oils or engine oil compositions during operation. Also is the quality deterioration to a certain extent depending on the driving style of the vehicle user. For this reason, it is currently proceeded to monitor the quality of the engine oil separately in order to alert the user in good time to an imminent oil change. This means that too short oil change intervals can be effectively avoided, which in addition to environmental relief also leads to cost savings for the operator of a motor vehicle.
  • a state sensor for liquids which monitors a respective flow behavior of the engine oil and thus its viscosity in the form of a vibrating body driven by a piezoelectric element, is known, for example, from DE 103 45 253 A1.
  • an increase in viscosity is caused by an increase in the density of the engine oil due to impurities.
  • Desirable is a low viscosity of an engine oil to achieve good lubricity and effective friction reduction within the internal combustion engine.
  • a bending oscillator element in contact with the engine oil is mechanically excited by at least one piezoelectric element to oscillate, wherein the at least one piezoelectric element is supplied with an amplitude-controlled electrical input signal.
  • the sensor element itself essentially consists of its carrier substrate with piezo-electrically active layers laminated thereon or integrated, which can act both as actuator layers and as sensor layers. Sensors of the type described are also referred to as trimorphic bending vibrators. Such elements can also be produced as a ceramic multilayer.
  • a difference between an applied electrical excitation or actuator voltage and a measured sensor output voltage is evaluated as a measure of the damping of the bending oscillator in the fluid or engine oil.
  • the resonance frequency and a respective resonance amplitude are evaluated as a measure of the density of the fluid.
  • An increasing density of the fluid leads to a Lowering the resonant frequency.
  • a decreasing viscosity leads to an increase in the amplitude.
  • a predetermined frequency band is tuned.
  • a resonant frequency is determined starting from a previously defined frequency zone. At the same time a resonance amplitude is read out.
  • the measurement principle briefly described above can also be implemented with other excitation methods, such as, for example, magnetically excited bending oscillators.
  • the measurement described above is based on the application of a constant actuator voltage, which is applied, for example, as a sinusoidal voltage and the reading of an attenuation-dependent measurement voltage.
  • a readjusted actuator voltage can be generated, so that in each case the measurement voltage remains constant.
  • a known compensation possibility consists in a one-time or periodically repeated calibration of the condition sensor in a reference liquid at a reference temperature. This procedure is in in motor vehicles built condition sensors impractical and therefore not feasible in principle.
  • a method according to the invention is accordingly distinguished by the fact that a state sensor is subjected to at least two excitation signals of different voltage levels and the respectively obtained measuring signals are compared with stored values. So that sensor output or measurement signals can be measured independently of drifts and gain changes at the sensor input, the invention thus makes use of a differential measurement. It was found that even a measurement with two different voltage levels and a comparison of the measured values with previously stored output values is sufficient to mask out the above-described temperature and aging-related effects and drifts.
  • a frequency range in which a resonant frequency is usually swept over in a preparatory measurement is usually swept over in a preparatory measurement. Subsequently, at least two measuring points are selected which have large deviations with respect to their respective measuring signal.
  • the evaluation and offset determination takes place virtually graphically via a comparison of straight lines in a diagram.
  • the pairs of values ascertained for the purpose of control are entered into a diagram and linearly extrapolated, into which the previously determined and stored values of an ideal sensor are also entered.
  • An offset results in this diagram as a zero shift or ordinate section.
  • grading curves are preferably used using known mathematical methods for minimizing the distance of a respective course to the measured values.
  • Figure 1 a schematic representation of a device according to the invention
  • FIG. 2 shows a result of a sweep with a constant number of oscillations with variation of amplitude and frequency. frequency on a bending vibrator under conditions of use;
  • Figure 4 an evaluation diagram for determining an offset value.
  • FIG. 1 shows a basic structure of a device for implementing a method according to the invention.
  • a sensor element S in the form of a piezoelectrically excited bending oscillator is arranged in the region of an oil pan in the engine oil OIL of an internal combustion engine M.
  • the sensor element S for electrical control of the actuator with an excitation voltage or input vibration A and for receiving and
  • reaction signals in the form of a result or measurement signal E connected to a controller C, which in turn communicates with a non-volatile data memory D.
  • the sensor element S is calibrated by the controller C.
  • the result is stored in the form of original value pairs in the data memory D for later call and for comparative evaluation.
  • the flexural vibrator is normally operated for density and viscosity measurement at a constant amplitude.
  • the flexural vibrator vibrates at a defined resonant frequency where it has its largest, damped amplitude. If the sensor element S ages, for example, as a result of a mechanical change in the clamping point or deposits on the electrode surfaces or the loss of the piezoelectric properties, this results in a change in the resonance frequency and in particular in the resonance amplitude, whose contributions are similar in magnitude to those of viscosity and density acting measuring signals E can lie.
  • the evaluation of the sensor signals E can be carried out in the vicinity of the resonant frequency, so does not necessarily have to be at resonant frequency.
  • the viscosity behavior of the fluid OIL usually does not change significantly within longer periods, ie in particular in the hour range.
  • the bending oscillator of the sensor element S represents a damped mechanical oscillating circuit whose resonant frequency also spreads within certain limits within a series. Since the position of the resonance frequency and a respective resonance amplitude as properties of the mechanical system are therefore not known exactly from the outset, test frequencies and test amplitudes are applied by the controller C to the sensor S in the course of this calibration process. In order to shorten the time required for this process, a fixed number of in this case only seven full oscillation periods is used for each of these test phases O 1 to D 5 according to the illustration of FIG. This ensures that Even in this very short period of time transient phenomena have already subsided.
  • Test signal with the parameter set of D 3 compared to the other results is maximum.
  • this parameter set is selected and stored in the data memory D for later access to the specific variables for safety.
  • a not exactly known resonance curve of the sensor element S is briefly traversed once to estimate its shape and its position. Subsequently, at least two measured values, in this case three measured values, are selected on this curve in order to subsequently determine age phenomena and the occurrence of offsets.
  • a repeat measurement for determining a possible deviation is carried out directly after passing through the test measurement marked in the dashed box.
  • such repetitions are not carried out immediately, but in cyclically or acyclically selected time intervals, since they are only used to monitor signs of aging on the Sensor S serve, not a study of the quality of the engine oil used.
  • FIG. 4 shows an evaluation diagram into which a measuring straight line of an ideal sensor has been entered, which has been determined on the basis of n measurements.
  • This straight line runs as a straight line of origin, because without stimulating amplitude and no reaction signal, and with small excitation even a small reaction signal is obtained.
  • the sensor is now operated a-periodically for multiples of the test interval lengths t n 'in a test mode.
  • the sensor element S is operated for a few seconds at a defined higher and / or lower voltage amplitude at a constant frequency.
  • the principal relationship with the aging influence can be seen in the amplitude-amplitude diagram of FIG. After a short transient phase in relation to a test interval length t n ', a ratio of exciting actuator voltage amplitude and measured output voltage amplitude remains unchanged with the viscosity and current amplitude
  • Density values of the fluid constant. If different actuator voltage amplitudes with associated output voltage amplitudes are entered in the diagram, the result is a linear relationship. The slope of the line is thus a representation of the transfer function. Drifting or offsets can be measured or determined by extrapolation. After determining an offset, a signal change actually caused by viscosity and density changes can be corrected.
  • the straight line of the sensor element S which is actually present is subsequently drawn into the diagram of FIG. 4, which in the present case has been registered using three measuring points as a straight line and has been linearly extrapolated to the origin of the diagram.
  • the diagram of Figure 4 has between the metered ideal sensor and the present real sensor the Grader slope M reduced to m, which is clearly interpreted as a sign of aging.
  • the offset By tilting the straight line this now no longer passes through the origin of the diagram, but cuts the amplitude axis above the origin, that is shifted by a section OS, the offset.
  • this offset must first be overcome by a stimulating oscillation, so that a reaction in the sensor in the form of a measurement signal S can be measured at all due to aging. Without compensating for this influence, the device thus determines values which have been corrupted by the offset OS.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Pathology (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Immunology (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Food Science & Technology (AREA)
  • Medicinal Chemistry (AREA)
  • Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

Abstract

La présente invention concerne un procédé et un dispositif pour faire fonctionner un capteur d'état destiné à des liquides. L'invention a pour objet de mettre au point un procédé et un dispositif de ce type, se caractérisant par l'aptitude à compenser des variations de point zéro et d'amplification liées au capteur. A cet effet, l'élément de détection (S) est relié à un dispositif de commande (C) pour réaliser la commande électrique avec une oscillation d'entrée (A) d'au moins deux amplitudes différentes, et pour recevoir et évaluer un signal de mesure (E), le dispositif de commande étant relié à une mémoire de données non volatile (D) dans laquelle sont enregistrées les valeurs des deux amplitudes ou plus de l'oscillation d'entrée d'excitation (A).
PCT/EP2006/064683 2005-08-09 2006-07-26 Procede et dispositif pour faire fonctionner un capteur d'etat destine a des liquides WO2007017383A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP06792574A EP1913361A1 (fr) 2005-08-09 2006-07-26 Procede et dispositif pour faire fonctionner un capteur d'etat destine a des liquides

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102005037634.7 2005-08-09
DE200510037634 DE102005037634A1 (de) 2005-08-09 2005-08-09 Verfahren und Vorrichtung zum Betreiben eines Zustandssensors für Flüssigkeiten

Publications (1)

Publication Number Publication Date
WO2007017383A1 true WO2007017383A1 (fr) 2007-02-15

Family

ID=37037639

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2006/064683 WO2007017383A1 (fr) 2005-08-09 2006-07-26 Procede et dispositif pour faire fonctionner un capteur d'etat destine a des liquides

Country Status (3)

Country Link
EP (1) EP1913361A1 (fr)
DE (1) DE102005037634A1 (fr)
WO (1) WO2007017383A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102022202581A1 (de) 2022-03-16 2023-09-21 Robert Bosch Gesellschaft mit beschränkter Haftung Testvorrichtung und Verfahren zum Testen eines Sensors, Sensorsystem

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4799378A (en) * 1985-10-21 1989-01-24 Alcor, Inc. Piezoelectric viscometer
WO1998009139A1 (fr) * 1996-08-28 1998-03-05 Videojet Systems International, Inc. Detecteurs de resonateurs utilisant des structures piezo-electriques a flexion pour detecter les proprietes de fluides
GB2366384A (en) * 2000-08-30 2002-03-06 Christopher Barnes Simultaneous or sequential measurement of viscous and dielectric material properties using the same sensor element
DE10345253A1 (de) * 2003-09-29 2005-05-04 Siemens Ag Zustandssensor für Flüssigkeiten

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3234787A (en) * 1961-04-14 1966-02-15 Baldwin Lima Hamilton Corp Strain gage transducer with impedance means for compensating for the characteristic nonlinearity of the gage
US6247354B1 (en) * 1998-05-13 2001-06-19 The United States Of America As Represented By The Secretary Of The Army Techniques for sensing the properties of fluids with resonators

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4799378A (en) * 1985-10-21 1989-01-24 Alcor, Inc. Piezoelectric viscometer
WO1998009139A1 (fr) * 1996-08-28 1998-03-05 Videojet Systems International, Inc. Detecteurs de resonateurs utilisant des structures piezo-electriques a flexion pour detecter les proprietes de fluides
GB2366384A (en) * 2000-08-30 2002-03-06 Christopher Barnes Simultaneous or sequential measurement of viscous and dielectric material properties using the same sensor element
DE10345253A1 (de) * 2003-09-29 2005-05-04 Siemens Ag Zustandssensor für Flüssigkeiten

Also Published As

Publication number Publication date
DE102005037634A1 (de) 2007-02-15
EP1913361A1 (fr) 2008-04-23

Similar Documents

Publication Publication Date Title
DE19706486B4 (de) Sensoreinrichtung zum Bestimmen des Alterungszustands flüssiger Medien
DE19910415B4 (de) Verfahren und Vorrichtung zum Abstimmen eines ersten Oszillators mit einem zweiten Oszillator
DE102005043037B4 (de) Vorrichtung mit piezoakustischem Resonatorelement, Verfahren zu dessen Herstellung und Verfahren zur Ausgabe eines Signals in Abhängigkeit einer Resonanzfrequenz
DE102005043039B4 (de) Vorrichtung mit piezoakustischem Resonatorelement, Verfahren zu dessen Herstellung und Verfahren zur Ausgabe eines Signals in Abhängigkeit einer Resonanzfrequenz
EP3329246B1 (fr) Déphaseur pour capteur vibronique
DE102018102535B3 (de) Temperaturmessung mittels der Impedanz eines Ultraschalltransducers
DE102011090015B4 (de) Vorrichtung zur Bestimmung und/oder Überwachung mindestens einer Prozessgröße
DE102011090014A1 (de) Vorrichtung zur Bestimmung und/oder Überwachung mindestens einer Prozessgröße
EP3045877A1 (fr) Procédé de fonctionnement d'un appareil de mesure de débit massique coriolis
WO2007087936A2 (fr) Dispositif et procédé de détection d'une substance dans un liquide
DE102015121621A1 (de) Vorrichtung zur sicheren Bestimmung und/oder Überwachung einer Prozessgröße
EP3521777A1 (fr) Capteur d'impédance et son procédé de fonctionnement
WO2000026661A1 (fr) Dispositif detecteur permettant de determiner les proprietes physiques de fluides
EP1864108A1 (fr) Procede et dispositif de mesure de viscosite de fluides non newtoniens, en particulier de substances necessaires au fonctionnement d'un moteur
DE10345253B4 (de) Verfahren zum Betreiben eines Zustandssensors für Flüssigkeiten
WO2007017383A1 (fr) Procede et dispositif pour faire fonctionner un capteur d'etat destine a des liquides
DE102004045528B4 (de) Vibrationssensor
EP1693663A2 (fr) Procédé et dispositif de determination de deux paramètres d'un fluide
EP4060295B1 (fr) Procédé de compensation de l'effet du nombre de reynolds sur la mesure d'un débitmètre massique de coriolis et appareil correspondant
DE3632591A1 (de) Verfahren und vorrichtung zur messung oder ueberwachung einer physikalischen eigenschaft eines fluessigen gegenstandes
WO2022122490A1 (fr) Système de capteur ultrasonore pour un véhicule à moteur et procédé de fonctionnement du système de capteur ultrasonore
DE10018665A1 (de) Längensensor mit Piezoeffekt
DE102005006853B4 (de) Messsystem und Verfahren zur Ankopplung eines Sensorelements in dem Messsystem
DE102017122567B4 (de) Vorrichtung und Verfahren zur Bestimmung von Eigenschaften leitfähiger oder dielektrischer Schichten
DE102006030657B4 (de) Fluidsensor zur Messung charakteristischer Eigenschaften eines Fluids

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2006792574

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

WWP Wipo information: published in national office

Ref document number: 2006792574

Country of ref document: EP