WO2018171990A1 - Method for detecting errors in an analog pressure sensor - Google Patents
Method for detecting errors in an analog pressure sensor Download PDFInfo
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- WO2018171990A1 WO2018171990A1 PCT/EP2018/053908 EP2018053908W WO2018171990A1 WO 2018171990 A1 WO2018171990 A1 WO 2018171990A1 EP 2018053908 W EP2018053908 W EP 2018053908W WO 2018171990 A1 WO2018171990 A1 WO 2018171990A1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/38—Controlling fuel injection of the high pressure type
- F02D41/3809—Common rail control systems
- F02D41/3836—Controlling the fuel pressure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/22—Safety or indicating devices for abnormal conditions
- F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
- F02D2041/223—Diagnosis of fuel pressure sensors
Definitions
- the present invention relates to a method for detecting an area-internal error of an analog pressure sensor.
- Analog pressure sensors are known. They are used for pressure detection in a variety of fields, for example in the automotive industry. For this purpose, in modern common-rail fuel injection systems, the rail pressure is regulated on the basis of feedback signals from a rail pressure sensor.
- Such a pressure sensor in particular a rail pressure sensor, is a high-pressure analog sensor which is mounted on the fuel rail in the case of a rail pressure sensor.
- the rail pressure sensor supplies an output signal in the form of a signal voltage V out to the engine control unit (ECU).
- the high-pressure sensor is supplied with voltage from the engine control unit ECU via a supply voltage V s and earth, which is used to operate the pressure sensor and as a reference voltage for the corresponding transfer function.
- the signal voltage delivered by the high pressure sensor is based on its transfer function programmed in its ASIC. Based on the received signal voltage V out and the corresponding calibration of the sensor, the rail pressure can be calculated by the ECU. However, the signal voltage measured by the control unit (ECU) may drift. In other words, the measured voltage value may differ from the actual value. In a pressurized system, in the worst case, this can lead to such a signal voltage deviation (Drift) can result in a system overpressure, ie the measured pressure value is less than the actual pressure value, which can ultimately cause a destruction of the system. There are two types of such signal deviation (signal drift). In a first type (signal offset drift), the measured signal voltage has a constant positive or negative drift over the pressure range. In a second type (gain drift), the measured signal voltage has a positive or negative signal deviation (drift), which increases over the pressure range.
- the measured signal voltage has a negative drift, i. the measured pressure is lower than the actual physical value, there is a risk of overpressure. If the measured signal voltage has a positive drift, i. the measured pressure is higher than the actual physical value, there is a risk of negative pressure. In the first place, such a signal drift is at one
- Analog sensor due to transmission interference. Since the corresponding information is transmitted by means of an electrical signal voltage, any disturbance of the signal between sensor and receiver can cause such a signal drift.
- a critical error is an in-band error in which the signal voltage measured by the ECU is still in the voltage range specified by the transfer function of the sensor.
- an error outside this range can be detected in a simple manner, since the signal voltage, for example of 5 V, is no longer in the voltage range of the sensor.
- Listed below are possible errors that can cause such an in-range failure, which can eventually lead to over-pressure and eventually system destruction. For example, an increase in electrical resistance in the supply line can cause negative offset drifts and negative gain drifts, resulting in overpressure. This is due to the reduction of the supply voltage for the sensor.
- the voltage is lowered from ⁇ by a short circuit and can be detected by the ECU, when the signal voltage reaches an appropriate range.
- a partial short circuit minimum resistance
- This type of "weak" short-circuit means that the pressure measured by the ECU is less than the actual value, which can eventually lead to overpressure.
- Tuning is sometimes performed to increase the power of the corresponding engine.
- the signal from the high-pressure sensor is specifically tuned so that it has a lower voltage.
- the maximum rail pressure reached becomes higher than the pressure measured by the ECU. This leads to an increase in the injection quantity, since the throughput is higher at a higher rail pressure.
- the present invention is based on the object
- Transfer function identifies a straight horizontal line after its maximum calibrated pressure value P max has been reached. This means that there is no further increase of the signal voltage over P max .
- Freezing the voltage value (cutting off the signal voltage) during the pumping process now indicates that the actual pressure has reached the maximum calibrated pressure of the sensor. In this case, a freezing of the voltage value can not take place if the actual pressure within the
- Transfer function range is because pump and Einspritzvor ⁇ gears generate corresponding pressure fluctuations.
- an overpressure as a result of an area-internal fault of the pressure sensor can therefore be determined when the pressure determined by the control unit lies below the maximum calibrated pressure value of the pressure sensor.
- the inventive method is carried out in particular on a pressure sensor which serves to detect the pressure in the rail of an internal combustion engine.
- the method according to the invention will now be described in detail by means of an exemplary embodiment in conjunction with the single FIGURE.
- the single figure shows pressure and pump capacity as a function of time, each in a diagram.
- the supply voltage was reduced on a rail pressure sensor to simulate drift (negative gain drift).
- drift negative gain drift
- the pressure measured by an ECU is always lower than the actual rail pressure measured by an external reference pressure sensor.
- the pumping process continues because the rail pressure measured by the ECU is below 2,000 bar. Therefore, the actual rail pressure continues to increase until it reaches the maximum calibrated pressure value of the sensor (2,400 bar). From this pressure level, the pressure measured by the ECU is frozen even though the pump's output is nearing full capacity.
- the pressure value of an external reference pressure sensor used is frozen at 3,000 bar, since the maximum calibrated pressure value for this sensor is 3,000 bar and the actual pressure still rises above 3,000 bar.
- the external reference pressure sensor has no in-range error since the frozen or cut voltage is at the maximum calibrated pressure value and not above or below.
- the measured from the ECU pressure bar frozen a ⁇ at about 1,800.
- the pressure sensor should be able to measure up to 2,400 bar (maximum calibrated pressure). There is always an active pumping process approaching the full capacity.
- the signal voltage measured by the ECU therefore has a negative drift, ie the actual pressure is around 600 bar higher than the measured pressure, at the point where freezing of the signal voltage value begins. It is therefore determined an internal error of the pressure sensor.
- the actual rail pressure measured by an external reference pressure sensor is shown.
- the rail pressure measured by the ECU is represented on the basis of a negative drift signal voltage. Since the actual rail pressure reaches the maximum calibrated pressure of the sensor, the voltage signal is frozen. This is due to the fact that the pressure sensor has reached the upper range limit of its transfer function.
- the second diagram shows the pump delivery rate as a function of time.
- the rail pressure control unit ECU
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Measuring Fluid Pressure (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Fuel-Injection Apparatus (AREA)
Abstract
Description
Beschreibung description
Verfahren zur Fehlererfassung bei einem analogen Drucksensor Die vorliegende Erfindung betrifft ein Verfahren zur Erfassung eines bereichsinternen Fehlers eines analogen Drucksensors. Method for error detection in an analog pressure sensor The present invention relates to a method for detecting an area-internal error of an analog pressure sensor.
Analoge Drucksensoren sind bekannt. Sie finden zur Druckerfassung auf einer Vielzahl von Gebieten Verwendung, bei- spielsweise in der Automobilindustrie. Dazu wird in modernen Common-Rail-Kraftstoffeinspritzsystemen der Raildruck auf der Basis von Feedback-Signalen von einem Raildrucksensor geregelt. Analog pressure sensors are known. They are used for pressure detection in a variety of fields, for example in the automotive industry. For this purpose, in modern common-rail fuel injection systems, the rail pressure is regulated on the basis of feedback signals from a rail pressure sensor.
Bei einem solchen Drucksensor, insbesondere Raildrucksensor, handelt es sich um einen analogen Hochdrucksensor, der im Fall eines Raildrucksensors am Kraftstoff-Rail montiert ist. Der Raildrucksensor liefert ein Ausgangssignal in der Form einer Signalspannung Vout an die Steuereinheit (ECU) des Motors. Der Hochdrucksensor wird von der Motorsteuereinheit ECU über eine Versorgungsspannung Vs und Erde mit Spannung versorgt, die zum Betreiben des Drucksensors und als Referenzspannung für die entsprechende Transferfunktion verwendet wird. Such a pressure sensor, in particular a rail pressure sensor, is a high-pressure analog sensor which is mounted on the fuel rail in the case of a rail pressure sensor. The rail pressure sensor supplies an output signal in the form of a signal voltage V out to the engine control unit (ECU). The high-pressure sensor is supplied with voltage from the engine control unit ECU via a supply voltage V s and earth, which is used to operate the pressure sensor and as a reference voltage for the corresponding transfer function.
Die vom Hochdrucksensor abgegebene Signalspannung basiert auf dessen in seinem ASIC programmierten Transferfunktion. Auf Basis der empfangenen Signalspannung Vout und der entsprechenden Kalibrierung des Sensors kann der Raildruck von der ECU berechnet werden . Die von der Steuereinheit (ECU) gemessene Signalspannung kann jedoch abdriften. Mit anderen Worten, der gemessene Spannungswert kann sich vom tatsächlichen Wert unterscheiden. Bei einem unter Druck stehenden System kann dies schlimmstenfalls dazu führen, dass eine derartige Signalspannungsabweichung (Drift) in einem Systemüberdruck resultieren kann, d.h. der gemessene Druckwert ist geringer als der tatsächliche Druckwert, was letztendlich eine Zerstörung des Systems bewirken kann. Es gibt zwei Arten einer derartigen Signalabweichung (Signaldrift) . Bei einer ersten Art (signal offset drift) besitzt die gemessene Signalspannung eine konstante positive oder negative Abweichung (Drift) über den Druckbereich. Bei einer zweiten Art (gain drift) besitzt die gemessene Signalspannung eine positive oder negative Signalabweichung (Drift) , die über den Druckbereich ansteigt. The signal voltage delivered by the high pressure sensor is based on its transfer function programmed in its ASIC. Based on the received signal voltage V out and the corresponding calibration of the sensor, the rail pressure can be calculated by the ECU. However, the signal voltage measured by the control unit (ECU) may drift. In other words, the measured voltage value may differ from the actual value. In a pressurized system, in the worst case, this can lead to such a signal voltage deviation (Drift) can result in a system overpressure, ie the measured pressure value is less than the actual pressure value, which can ultimately cause a destruction of the system. There are two types of such signal deviation (signal drift). In a first type (signal offset drift), the measured signal voltage has a constant positive or negative drift over the pressure range. In a second type (gain drift), the measured signal voltage has a positive or negative signal deviation (drift), which increases over the pressure range.
Hat die gemessene Signalspannung eine negative Drift, d.h. der gemessene Druck ist niedriger als der tatsächliche physikalische Wert, besteht das Risiko eines Überdrucks. Hat die gemessene Signalspannung eine positive Drift, d.h. der gemessene Druck ist höher als der tatsächliche physikalische Wert, besteht das Risiko eines Unterdrucks. In erster Linie ist eine derartige Signaldrift bei einemIf the measured signal voltage has a negative drift, i. the measured pressure is lower than the actual physical value, there is a risk of overpressure. If the measured signal voltage has a positive drift, i. the measured pressure is higher than the actual physical value, there is a risk of negative pressure. In the first place, such a signal drift is at one
Analogsensor auf Übertragungsstörungen zurückzuführen. Da die entsprechende Information mithilfe einer elektrischen Signalspannung übertragen wird, kann jede Störung des Signals zwischen Sensor und Empfänger eine solche Signaldrift verur- Sachen. Ein kritischer Fehler ist dabei ein bereichsinterner Fehler, bei dem die von der ECU gemessene Signalspannung noch in dem Spannungsbereich liegt, der durch die Transferfunktion des Sensors spezifiziert ist. Ein Fehler außerhalb dieses Bereiches kann dagegen auf einfache Weise detektiert werden, da die Signalspannung, beispielsweise von 5 V, nicht mehr im Spannungsbereich des Sensors liegt. Nachfolgend sind mögliche Fehler aufgeführt, die einen derartigen bereichsinternen Fehler verursachen können, welcher letztendlich zu einem Überdruck und schließlich zur Systemzerstörung führen kann. Beispielsweise kann ein Anstieg des elektrischen Widerstandes in der Versorgungsleitung negative Offset-Drifts und negative Gain-Drifts bewirken, die in einem Überdruck resultieren. Dies ist auf die Reduzierung der Versorgungsspannung für den Sensor zurückzuführen. Analog sensor due to transmission interference. Since the corresponding information is transmitted by means of an electrical signal voltage, any disturbance of the signal between sensor and receiver can cause such a signal drift. A critical error is an in-band error in which the signal voltage measured by the ECU is still in the voltage range specified by the transfer function of the sensor. On the other hand, an error outside this range can be detected in a simple manner, since the signal voltage, for example of 5 V, is no longer in the voltage range of the sensor. Listed below are possible errors that can cause such an in-range failure, which can eventually lead to over-pressure and eventually system destruction. For example, an increase in electrical resistance in the supply line can cause negative offset drifts and negative gain drifts, resulting in overpressure. This is due to the reduction of the supply voltage for the sensor.
Eine weitere Fehlerquelle ist in Kurzschlüssen zu sehen. Another source of error is seen in short circuits.
Normalerweise wird durch einen Kurzschluss die Spannung ab¬ gesenkt und kann von der ECU detektiert werden, wenn die Signalspannung einen entsprechenden Bereich erreicht. Ein partieller Kurzschluss (minimaler Widerstand) kann jedoch zu einer Reduzierung des Spannungssignals führen, ohne dass dies von der Kurzschlussdiagnose der ECU detektiert wird. Diese Art eines „schwachen" Kurzschlusses bedeutet, dass der von der ECU ge- messene Druck geringer ist als der tatsächliche Wert. Auch dies kann schließlich zu einem Überdruck führen. Normally, the voltage is lowered from ¬ by a short circuit and can be detected by the ECU, when the signal voltage reaches an appropriate range. A partial short circuit (minimum resistance), however, can lead to a reduction of the voltage signal without being detected by the short circuit diagnosis of the ECU. This type of "weak" short-circuit means that the pressure measured by the ECU is less than the actual value, which can eventually lead to overpressure.
Um die Leistung des entsprechenden Motors zu steigern, wird manchmal ein Tuning durchgeführt. Das Signal vom Hochdrucksensor wird dabei gezielt so getunt, dass es eine geringere Spannung aufweist. Als Folge davon wird der erreichte maximale Raildruck höher als der von der ECU gemessene Druck. Dies führt zu einem Anstieg der Einspritzmenge, da der Durchsatz bei einem höheren Raildruck höher ist. Tuning is sometimes performed to increase the power of the corresponding engine. The signal from the high-pressure sensor is specifically tuned so that it has a lower voltage. As a result, the maximum rail pressure reached becomes higher than the pressure measured by the ECU. This leads to an increase in the injection quantity, since the throughput is higher at a higher rail pressure.
Eine weitere Fehlerquelle ist darauf zurückzuführen, dass die Versorgungsspannung des Drucksensors außerhalb von dessen Bereich liegt. Da die Versorgungsspannung auch als Referenzspannung für die Transferfunktion benutzt wird, kann jegliche Abweichung dazu führen, dass die Signalspannung des Drucksensors eine Drift besitzt, d.h. eine niedrigere Versorgungsspannung kann eine negative Gain-Drift mit einem Überdruckrisiko be¬ wirken . Die vorstehend aufgezeigten Probleme hat man bisher in der folgenden Weise gelöst. Man hat ein mechanisches Druckbe¬ grenzungsventil (PLV) vorgesehen, um das Entstehen von Überdruck zu verhindern. Eine andere Lösung besteht darin, ein redundantes System mit mehreren Raildrucksensoren anzuordnen. Auch hat man Drucksensoren mit einem digitalen Ausgangssignal vorgesehen. Another source of error is due to the fact that the supply voltage of the pressure sensor is outside its range. Since the supply voltage is also used as reference voltage for the transfer function, any deviation can cause the signal voltage of the pressure sensor has a drift, ie a lower supply voltage can be a negative gain drift with a risk of overpressure be ¬ act. The above problems have been solved in the following manner. It has a mechanical provided Druckbe ¬ relief valve (PLV) to prevent the generation of excess pressure. Another solution is to arrange a redundant system with multiple rail pressure sensors. Also, one has provided pressure sensors with a digital output signal.
Diese Lösungen sind jedoch mit zusätzlichen Kosten verbunden. Der vorliegenden Erfindung liegt die Aufgabe zugrunde, einHowever, these solutions are associated with additional costs. The present invention is based on the object
Verfahren zur Erfassung eines bereichsinternen Fehlers eines analogen Drucksensors zur Verfügung zu stellen, mit dem ein bereichsinterner Fehler des Drucksensors auf besonders wirt¬ schaftliche Weise ermittelt werden kann. To provide methods for detecting an in-range error of an analog pressure sensor with which an area-internal error of the pressure sensor can be determined in a particularly wirt ¬ economical way.
Diese Aufgabe wird erfindungsgemäß bei einem derartigen Ver¬ fahren durch die folgenden Schritte gelöst: This objective is achieved in such Ver ¬ go through the following steps:
Durchführen einer Druckmessung mit dem Drucksensor und einer an diesen angeschlossenen Steuereinheit; Performing a pressure measurement with the pressure sensor and a control unit connected thereto;
Durchführen einer Druckmessung mit einem externen Referenz-Drucksensor; wenn der vom externen Referenz-Drucksensor gemessene tatsächliche Druck den maximalen kalibrierten Druckwert des Drucksensors erreicht hat, Einfrieren des von der Steuereinheit des Drucksensors ermittelten Drucks; und Feststellen eines betriebsinternen Fehlers des Drucksensors, wenn der von der Steuereinheit ermittelte Druck von dem ge¬ messenen tatsächlichen Druck entsprechend dem maximalen kalibrierten Druckwert abweicht. Die erfindungsgemäß durchgeführte Strategie basiert auf der Tatsache, dass der Drucksensor an der Obergrenze seiner Performing a pressure measurement with an external reference pressure sensor; when the actual pressure measured by the external reference pressure sensor has reached the maximum calibrated pressure value of the pressure sensor, freezing the pressure detected by the control unit of the pressure sensor; and detecting an internal fault operation of the pressure sensor when the pressure of the ge ¬ measured actual pressure determined by the control unit is different according to the maximum calibrated pressure value. The strategy implemented according to the invention is based on the fact that the pressure sensor is at the upper limit of its pressure
Transferfunktion eine gerade horizontale Linie ausweist, nachdem sein maximaler kalibrierter Druckwert Pmax erreicht worden ist. Das bedeutet, dass es keinen weiteren Anstieg der Signalspannung über Pmax gibt. Transfer function identifies a straight horizontal line after its maximum calibrated pressure value P max has been reached. This means that there is no further increase of the signal voltage over P max .
Ein Einfrieren des Spannungswertes (Abschneiden der Signalspannung) während des Pumpvorganges zeigt nunmehr an, dass der tatsächliche Druck den maximalen kalibrierten Druck des Sensors erreicht hat. Dabei kann ein Einfrieren des Spannungswertes nicht stattfinden, wenn der tatsächliche Druck innerhalb des Freezing the voltage value (cutting off the signal voltage) during the pumping process now indicates that the actual pressure has reached the maximum calibrated pressure of the sensor. In this case, a freezing of the voltage value can not take place if the actual pressure within the
Transferfunktionsbereiches liegt, da Pump- und Einspritzvor¬ gänge entsprechende Druckschwankungen erzeugen. Transfer function range is because pump and Einspritzvor ¬ gears generate corresponding pressure fluctuations.
Wenn ein derartiges Einfrieren der Signalspannung detektiert und der von der ECU gemessene Druck unterhalb des maximalen ka¬ librierten Druckwertes des Sensors liegt, wird ein Überdruck infolge eines bereichsinternen Fehlers des Drucksensors be- stätigt. Der Pumpvorgang kann dann in einem nächsten Schritt sofort gestoppt werden, um einen weiteren Druckanstieg zu verhindern, der zu einer Zerstörung des Systems führen könnte. If such a freezing of the signal voltage is detected and measured by the ECU pressure below the maximum ka ¬ libri Erten pressure value of the sensor is, an excess pressure due to an internal error range of the pressure sensor confirms loading. The pumping process can then be stopped immediately in a next step to prevent further pressure increase, which could lead to destruction of the system.
Insbesondere kann daher ein Überdruck infolge eines be- reichsinternen Fehlers des Drucksensors festgestellt werden, wenn der von der Steuereinheit ermittelte Druck unter dem maximalen kalibrierten Druckwert des Drucksensors liegt. In particular, an overpressure as a result of an area-internal fault of the pressure sensor can therefore be determined when the pressure determined by the control unit lies below the maximum calibrated pressure value of the pressure sensor.
Wie bereits erwähnt, wird bei Feststellung eines Überdrucks vorzugsweise eine weitere Druckerhöhung gestoppt. As already mentioned, upon detection of an overpressure, a further pressure increase is preferably stopped.
Das erfindungsgemäße Verfahren wird insbesondere an einem Drucksensor durchgeführt, der zur Erfassung des Drucks im Rail einer Brennkraftmaschine dient. Das erfindungsgemäße Verfahren wird nachfolgend anhand eines Ausführungsbeispieles in Verbindung mit der einzigen Figur im Detail beschrieben. Die einzige Figur zeigt Druck und Pumpenförderleistung in Abhängigkeit von der Zeit, jeweils in einem Diagramm. The inventive method is carried out in particular on a pressure sensor which serves to detect the pressure in the rail of an internal combustion engine. The method according to the invention will now be described in detail by means of an exemplary embodiment in conjunction with the single FIGURE. The single figure shows pressure and pump capacity as a function of time, each in a diagram.
An einem Raildrucksensor wurde die Versorgungsspannung reduziert, um eine Drift zu simulieren (negative gain drift) . Während eines Raildruckanstieges ist der von einer ECU gemessene Druck immer niedriger als der von einem externen Referenzdrucksensor gemessene tatsächliche Raildruck. Obwohl der tatsächliche Raildruck einen Drucksollwert von 2.000 bar erreicht hat, setzt sich der Pumpvorgang noch fort, da der von der ECU gemessene Raildruck unter 2.000 bar liegt. Daher steigt der tatsächliche Raildruck weiter an, bis er den maximalen kalibrierten Druckwert des Sensors erreicht (2.400 bar) . Von diesem Druckniveau an wird der von der ECU gemessene Druck eingefroren, obwohl sich die Förderleistung der Pumpe der vollen Leistung nähert. Bei dieser Messung wird auch der Druckwert eines verwendeten externen Referenz-Drucksensor bei 3.000 bar eingefroren, da der maximale kalibrierte Druckwert für diesen Sensor bei 3.000 bar liegt und der tatsächliche Druck noch über 3.000 bar ansteigt. Der externe Referenz-Drucksensor besitzt keinen bereichsinternen Fehler, da die eingefrorene bzw. abgeschnittene Spannung am maximalen kalibrierten Druckwert und nicht darüber oder darunter liegt. The supply voltage was reduced on a rail pressure sensor to simulate drift (negative gain drift). During a rail pressure rise, the pressure measured by an ECU is always lower than the actual rail pressure measured by an external reference pressure sensor. Although the actual rail pressure has reached a pressure set point of 2,000 bar, the pumping process continues because the rail pressure measured by the ECU is below 2,000 bar. Therefore, the actual rail pressure continues to increase until it reaches the maximum calibrated pressure value of the sensor (2,400 bar). From this pressure level, the pressure measured by the ECU is frozen even though the pump's output is nearing full capacity. In this measurement, the pressure value of an external reference pressure sensor used is frozen at 3,000 bar, since the maximum calibrated pressure value for this sensor is 3,000 bar and the actual pressure still rises above 3,000 bar. The external reference pressure sensor has no in-range error since the frozen or cut voltage is at the maximum calibrated pressure value and not above or below.
Der von der ECU gemessene Druck wird bei etwa 1.800 bar ein¬ gefroren. Der Drucksensor sollte in der Lage sein, bis 2.400 bar (maximaler kalibrierter Druckwert) zu messen. Es liegt dabei immer ein aktiver Pumpvorgang vor, der sich der vollen Förderleistung annähert. The measured from the ECU pressure bar frozen a ¬ at about 1,800. The pressure sensor should be able to measure up to 2,400 bar (maximum calibrated pressure). There is always an active pumping process approaching the full capacity.
Die von der ECU gemessene Signalspannung besitzt daher eine negative Drift, d.h. der tatsächliche Druck ist um etwa 600 bar höher als der gemessene Druck, und zwar an dem Punkt, an dem mit dem Einfrieren des Signalspannungswertes begonnen wird. Es wird daher ein betriebsinterner Fehler des Drucksensors festgestellt. In dem Druck-Zeit-Diagramm der einzigen Figur ist der von einem externen Referenzdrucksensor gemessene tatsächliche Raildruck dargestellt. Ferner ist der von der ECU gemessene Raildruck auf Basis einer Signalspannung mit negativer Drift dargestellt. Da der tatsächliche Raildruck den maximalen kalibrierten Druck des Sensors erreicht, wird das Spannungssignal eingefroren. Dies ist auf die Tatsache zurückzuführen, dass der Drucksensor die obere Bereichsgrenze seiner Transferfunktion erreicht hat. The signal voltage measured by the ECU therefore has a negative drift, ie the actual pressure is around 600 bar higher than the measured pressure, at the point where freezing of the signal voltage value begins. It is therefore determined an internal error of the pressure sensor. In the pressure-time diagram of the single figure, the actual rail pressure measured by an external reference pressure sensor is shown. Further, the rail pressure measured by the ECU is represented on the basis of a negative drift signal voltage. Since the actual rail pressure reaches the maximum calibrated pressure of the sensor, the voltage signal is frozen. This is due to the fact that the pressure sensor has reached the upper range limit of its transfer function.
Im zweiten Diagramm ist die Pumpenförderleistung in Abhängigkeit von der Zeit dargestellt. Da die Druckabweichung infolge der Drift zunimmt, versucht die Raildrucksteuereinheit (ECU) eine Kompensation herbeizuführen, indem die Pumpenförderleistung erhöht und schließlich volle Leistung erreicht wird. The second diagram shows the pump delivery rate as a function of time. As the pressure drift increases due to drift, the rail pressure control unit (ECU) attempts to compensate by increasing the pump delivery rate and ultimately achieving full performance.
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| DE102017204827.1A DE102017204827B4 (en) | 2017-03-22 | 2017-03-22 | Method for error detection in an analog pressure sensor |
| DE102017204827.1 | 2017-03-22 |
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| DE102008024956A1 (en) * | 2008-05-23 | 2009-11-26 | Continental Automotive Gmbh | Method for checking a pressure sensor of a fuel storage device |
| DE102008043413A1 (en) * | 2008-11-03 | 2010-05-06 | Robert Bosch Gmbh | Rail pressure sensor output signal validation method for direct-injection internal-combustion engine of vehicle, involves comparing digital signal with analog signal for validation of analog signal |
| DE102014214452B3 (en) * | 2014-07-23 | 2015-06-11 | Continental Automotive Gmbh | Method and device for detecting a faulty rail pressure sensor |
| US20160053706A1 (en) * | 2013-04-11 | 2016-02-25 | Robert Bosch Gmbh | Method for operating a common-rail system of a motor vehicle having a redundant common-rail-pressure sensor |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008001444A1 (en) | 2008-04-29 | 2009-11-05 | Robert Bosch Gmbh | Method for determining an overpressure in a fuel accumulator of an injection system of an internal combustion engine |
| JP5464185B2 (en) | 2011-09-05 | 2014-04-09 | 株式会社デンソー | Fuel injection control system |
| GB2543473A (en) | 2015-06-03 | 2017-04-26 | Gm Global Tech Operations Llc | Method of diagnosing a fuel rail pressure sensor |
-
2017
- 2017-03-22 DE DE102017204827.1A patent/DE102017204827B4/en active Active
-
2018
- 2018-02-16 WO PCT/EP2018/053908 patent/WO2018171990A1/en not_active Ceased
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| DE19959678A1 (en) * | 1999-12-10 | 2001-06-21 | Bosch Gmbh Robert | Course inspection of characteristic curve of sensor involves adjusting sensor offset by zero value of input value and monitoring output quantity at reference point to detect change in characteristic curve |
| DE102008024956A1 (en) * | 2008-05-23 | 2009-11-26 | Continental Automotive Gmbh | Method for checking a pressure sensor of a fuel storage device |
| DE102008043413A1 (en) * | 2008-11-03 | 2010-05-06 | Robert Bosch Gmbh | Rail pressure sensor output signal validation method for direct-injection internal-combustion engine of vehicle, involves comparing digital signal with analog signal for validation of analog signal |
| US20160053706A1 (en) * | 2013-04-11 | 2016-02-25 | Robert Bosch Gmbh | Method for operating a common-rail system of a motor vehicle having a redundant common-rail-pressure sensor |
| DE102014214452B3 (en) * | 2014-07-23 | 2015-06-11 | Continental Automotive Gmbh | Method and device for detecting a faulty rail pressure sensor |
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| FOXWELL: "Diagnosing CRD faults with a Pressure Tester", 8 February 2014 (2014-02-08), XP055471443, Retrieved from the Internet <URL:http://www.foxwell.com.au/diagnosing-crd-faults-with-a-pressure-tester/> [retrieved on 20180430] * |
Also Published As
| Publication number | Publication date |
|---|---|
| DE102017204827A1 (en) | 2018-09-27 |
| DE102017204827B4 (en) | 2019-08-08 |
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