EP2042716A1 - Verfahren zur Einspritzstromsteuerung durch eine Einspritzdüse in einem Verbrennungsmotor und Kraftstoffeinspritzsystem zur Steuerung eines Einspritzstroms - Google Patents

Verfahren zur Einspritzstromsteuerung durch eine Einspritzdüse in einem Verbrennungsmotor und Kraftstoffeinspritzsystem zur Steuerung eines Einspritzstroms Download PDF

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Publication number
EP2042716A1
EP2042716A1 EP07018760A EP07018760A EP2042716A1 EP 2042716 A1 EP2042716 A1 EP 2042716A1 EP 07018760 A EP07018760 A EP 07018760A EP 07018760 A EP07018760 A EP 07018760A EP 2042716 A1 EP2042716 A1 EP 2042716A1
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EP
European Patent Office
Prior art keywords
current
phase
injection current
battery voltage
wiring harness
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.)
Withdrawn
Application number
EP07018760A
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English (en)
French (fr)
Inventor
Michele Bastianelli
Luca Chiapusso
Paolo Zamboni
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GM Global Technology Operations LLC
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GM Global Technology Operations LLC
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Publication date
Application filed by GM Global Technology Operations LLC filed Critical GM Global Technology Operations LLC
Priority to EP07018760A priority Critical patent/EP2042716A1/de
Publication of EP2042716A1 publication Critical patent/EP2042716A1/de
Withdrawn legal-status Critical Current

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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/20Output circuits, e.g. for controlling currents in command coils
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D41/00Electrical control of supply of combustible mixture or its constituents
    • F02D41/20Output circuits, e.g. for controlling currents in command coils
    • F02D2041/202Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
    • F02D2041/2065Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit the control being related to the coil temperature
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02DCONTROLLING COMBUSTION ENGINES
    • F02D2200/00Input parameters for engine control
    • F02D2200/50Input parameters for engine control said parameters being related to the vehicle or its components
    • F02D2200/503Battery correction, i.e. corrections as a function of the state of the battery, its output or its type

Definitions

  • the invention relates to a method for controlling an injection current through an injector of an internal combustion machine and to a fuel injection system for controlling an injection current.
  • Electronically controlled fuel injectors can be distinguished in high voltage injectors and low voltage injectors.
  • High voltage injectors need a boosted voltage larger than the battery voltage to ensure a reliable injection of fuel into the combustion chamber as it is shown in the US 2005/0126543 A1 .
  • voltage low injectors may be driven from the battery voltage of the vehicle, for example at nominal 13,5 V. It was observed that the control of the fuel is less precise than for high voltage injectors.
  • the invention provides a method for controlling an injection current through an injector of an internal combustion machine.
  • the injection current is driven by a battery voltage and the injector is connected to the battery via a wiring harness.
  • the word current is used for the electric current and not for the flow of fuel that is initiated by the electric current.
  • the battery voltage is sensed and the wiring harness resistance is estimated before adapting the injection current according to the battery voltage and the wiring harness resistance.
  • the injection current was observed to depend on the battery voltage and on the wiring harness resistance. Taking these parameters into account makes it possible to generate a current signal that is as precise as possible.
  • the usage of the low voltage injectors is critical due to the effects of battery voltage drop and wiring harness resistance on and their dependencies of the rail pressure for the delivered fuel quantity delivered.
  • the method considers the importance of the complete management of the injection current profile peak phase to drive the low voltage injectors in right way and achieve the desired fuel quantity requirements for low voltage injectors.
  • the precise control ensures a more precise fuel delivery and therefore lower emissions of the engine.
  • the fuel is provided by a common rail for a plurality of injectors and the pressure in this common rail is measured to adapt of the injection current also according to the pressure in the common rail.
  • the pressure in a common rail is usually regulated within a regulation range. A high pressure increases the volume of injected fuel and, accordingly, the current signal is also adapted according to the rail pressure to provide a complete control of the fuel quantity.
  • the injection current is started earlier in the first configuration than in the second configuration. It was observed that the voltage injection starts earlier if the battery voltage is higher. Accordingly, the injection current is corrected by adapting its start.
  • the injection current signal comprises an idle phase, a pull-in phase and a hold-in phase.
  • the idle phase is characterized in that the injection current equals an idle level A0 which is 0 A.
  • the current increases and reaches at least a pull-in current level A2.
  • the hold-in phase following the pull-in phase, the current level equals a hold-in current level A1, whereby the following relation between A2 and A1 holds: A2 > A1 > 0.
  • the start of the injection current is defined as the time when the idle phase ends and the pull-in phase begins.
  • the start of the injection current is adapted according to the battery voltage and the duration of the pull-in phase is adapted according to the rail pressure.
  • the compensation needed for the rail pressure was found to be independent of the compensations for the battery voltage and the wiring harness such that the pressure should also be compensated independently of the other compensations.
  • the resistance or the wiring harness was observed to be related to temperature of the wiring harness.
  • the wiring harness is preferably estimated by measuring a delay t* measured from the start of the injection current to the time when the injected current exceeds a predetermined threshold. Then, the measured delay t* measured is compared with a correlation table that comprises delays t* for a plurality of wiring harness resistances.
  • This correction table may be generated on a test bench and be stored in the internal combustion engine during the production of the engine. The table may for example be stored in a memory of a electronic control unit (ECU) or in a separate Flash-EEPROM.
  • the method may be started after the cranking of the engine when the battery voltage has been stabilized.
  • the invention further provides a fuel injection system for controlling an injection current through an electronically controlled fuel injector of an internal combustion engine.
  • the fuel injection system comprises a wiring harness that connects the fuel injector with a battery voltage and a measure unit having an output for outputting a measured battery voltage.
  • An estimation unit has an output for outputting an estimated resistance of the wiring harness.
  • An adaptor has an output for outputting the injection current signal and adapts the injection current signal according to the outputs of the measure unit and the estimation unit.
  • the compensation of the battery voltage drop and wiring harness resistance effects during the driving of low voltage injectors setup on a engine ensures a complete control the quantity of fuel delivered into the combustion chambers.
  • the engine is preferable a diesel engine in which the low voltage injectors are used
  • the fuel injection system further comprises a detection unit for detecting the pressure in the common rail and the adaptor adapts the injection current signal also according to the pressure in the common rail.
  • the adaptor adapts the start of the injection current signal according to the battery voltage and the wiring harness resistance and adapts the duration of the current according to the wiring harness resistance.
  • the adaptor starts the injection current later in the case of a high battery voltage than in the case of a low battery voltage to ensure a stable injection current independently of the voltage conditions.
  • Exemplary waveforms of the injection current are illustrated in Figure 1 showing the injection current for eight different battery voltage conditions.
  • the curve K 7 gives the current profile at the highest battery voltage, whereas the battery voltage decreases from curve to curve, reaching the lowest battery voltage for the curve K1.
  • the delay between the start of the injection current and the start of the fuel quantity delivery is smaller than the respective delay for a low battery voltage.
  • the start of the injection current is started already at t 1 .
  • the current After the start of the injection current, the current increases, whereby the slope of the curves at higher battery voltages is higher than the slope of the curves of lower battery voltages.
  • the current reaches a maximum, in case of the curve K 1 , at about 16 A and, in the case of K7, at a level of more than 25 A.
  • the current decreases to a hold-in current level A1, which is kept for a duration t h .
  • This duration t h may vary from curve to curve.
  • the current drops to 0 A.
  • the shown injection currents profiles are divided into three phases. The first phase is the idle phase, in which the current is zero. The idle phase is followed by the pull-in phase, which starts at the respective times t 1 to t 7 . In the pull-in phase, the current is increased to a maximum. It is important to note that all curves K1 to K7 exceed a predetermined threshold pull-in current level, being labelled as A2 in Figure 1 . During the third, the hold-in phase, the current is kept at a hold-in current level A1.
  • the current profile After the hold-in phase, the current profile returns back to the idle phase. For each fuel injection, the current profile of Figure 1 is repeated. As the fuel is injected periodically, the current profile of Figure 1 is repeated periodically, too.
  • the higher pull-in current exceeding the pull-in current level A2 is needed to quickly open the fuel injector. This decreases the response time, which is the time between the initiation of fuel injection current signal and the time when fuel actually begins to enter the engine cylinder. Once the fuel injection has started, a lower level hold-in current can be used to hold the injector open for the remaining injection.
  • the curves K1 to K7 were measured on an engine test bench.
  • the battery voltages varied between 13,5 and 12 V, but the rail pressure and the wiring harness resistance were kept unchanged.
  • the measurements show that the injection currents need to be adapted to run the internal combustion engine independently of the battery voltage conditions. To align the injection current profiles in respect to their flex points, the start of the injection needs to be corrected to maintain the desired start of the fuel delivery.
  • This correction works in opportune manner by starting the injection current earlier at low battery voltage conditions.
  • the compensation of the battery voltage drop is based on a calibration table with computed correction values. These correction values are applied according to the measured battery voltage.
  • a battery voltage is measured which would lead to the curve K 6 .
  • the correction value for this voltage is a time shift that equals t 6 - t 7 .
  • the pull-in phase needs to be started earlier than in the case of a battery voltage of the curve K7. Accordingly, the injection current is started t 6 - t 7 earlier.
  • the curve F1 to F7 show the fuel deliveries into the combustion chamber.
  • the current injections were delayed according to the above-described method such that the fuel was delivered at the same time for all cases.
  • the curves F1 to F7 shows basically the same course.
  • the number of the fuel delivery curves F1 to F7 equal to the number of activating current curve K1 to K7, e.g. the fuel delivery of curve F2 was activated by the injection current according to curve
  • Figure 2 shows an injection current profile as in Figure 1 .
  • the time between the start of the pull-in phase and the crossing of the current with the pull-in current level A 2 is marked with t*. It should be noted that for the following method not only the pull-in current level A2, but also other current levels may be chosen.
  • the effect of the wiring harness has been studied by estimating the resistance value.
  • the electrical characteristics of the low voltage injectors at nominal conditions which means at nominal battery voltage and with a neglectable wiring harness, are measured.
  • the harness resistance value are estimated based on the measurement of the time elapsed between the start of injection current profile and the achievement of a fixed current threshold. This time is labelled as t* in Figure 2 and based on this time t* the correction factors to be applied are computed.
  • the application of the wiring harness compensation first requires the determination of a basic database for different wiring harness conditions. This database is based on a test in which different harness conditions were measured on a test bench. The database is then used for computing of the correction factors. The procedure to determinate the basic database of correction factors is resumed by the following steps:
  • the nominal wiring harness resistance is included in this number.
  • t* Rx, Vy is time elapsed between the start of injection current profile and achieving the current threshold with the wiring harness resistance Rx and battery voltage Vy condition.
  • C Rx, Vy is the correction factor for the wiring harness resistance Rx and battery voltage Vy condition.
  • the correction factor comprises a delay specifying how much earlier or later the injection current has to be started in comparison to the nominal condition.
  • the delay of the injection current is in the range between +130 ⁇ s and -30 ⁇ s in relation to the nominal case, whereby the injection current starts +130 ⁇ s earlier than the nominal case for the lowest battery voltage and 30 ⁇ s later in the case of the highest battery voltage.
  • the correction factor also comprises the value describing the length of the duration of the injection current.
  • the duration equals the sum of the length of the hold-in phase and the length of the pull-in phase.
  • the duration start at the start of the time t* and ends at the time when the current reaches the zero level again.
  • the change of the duration is in the range of [-30 ⁇ s; +130 ⁇ s] in relation to nominal conditions.
  • the correction factor can be estimated according to the following method. Based on the stored database, the proposed method is able to determine the correction factor to be applied in any other wiring harness and battery voltage condition by the following steps:
  • Figure 3 shows the correction factors in diagram with t* as y-axis and the battery voltage V as x-axis.
  • the correction factors listed in the database are distributed in this t*-V-diagram.
  • the measured values, voltage V measured and delay t* measured are not listed in the database. However, the measured values lie between the delays t* and battery voltages V of the listed correction factors C R2, Vk , C R2, Vk+1 , C Rx-1, Vk and C Rx-1, Vk-1 .
  • the correction factors for the measured values are calculated by interpolating the correction factors of the neighbouring values C R2, Vk , C R2, Vk+1 , C Rx-1, Vk and C Rx-1, Vk-1 given in the database.
  • the rail pressure of the common rail has an influence on the volume of injected fuel. Accordingly, deviations of the rail pressure should also be compensated.
  • Driving the low voltage injectors with high current is used for the opening of the needle during the pull-in phase. After this phase is not necessary to energize the injectors so much. For this reason, driving the low voltage injectors with high current is kept only for a short pull-in time based on the rail pressure measurement. After this pull-in time it is sufficient to drive the injector with a low current.
  • the proposed method is used in embodiment not during the cranking of the engine.
  • the battery voltage is low and consequently the usage of the method proposed in both conditions would require to define a low current threshold (A2) which involves a low measurement resolution of the time t* elapsed between the start of injection current profile and current threshold achievement.
  • A2 low current threshold
  • the most important task is to start the engine. Accordingly, the compensation is based only on the engine coolant temperature and the battery voltage.
  • the compensation is computed with the method according to the invention.
  • the length of the pull-in phase is changed.
  • the duration of the pull-in phase is ceteris paribus shorter than at a low rail pressure.
  • the rail pressure compensation is based on a calibration table, which computes the time necessary to drive the injectors with the high current as function of rail pressure.
  • Figure 4 gives an overview of the compensation method for the injection current.
  • the battery voltage and the rail pressure are measured and independently compensated.
  • the wiring harness is estimated based on the measured time t* and the battery voltage V Battery .
  • the temperature of the engine is also taken into account because the resistance was found to highly depend also on the temperature of the wiring harness.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
EP07018760A 2007-09-25 2007-09-25 Verfahren zur Einspritzstromsteuerung durch eine Einspritzdüse in einem Verbrennungsmotor und Kraftstoffeinspritzsystem zur Steuerung eines Einspritzstroms Withdrawn EP2042716A1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP07018760A EP2042716A1 (de) 2007-09-25 2007-09-25 Verfahren zur Einspritzstromsteuerung durch eine Einspritzdüse in einem Verbrennungsmotor und Kraftstoffeinspritzsystem zur Steuerung eines Einspritzstroms

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EP07018760A EP2042716A1 (de) 2007-09-25 2007-09-25 Verfahren zur Einspritzstromsteuerung durch eine Einspritzdüse in einem Verbrennungsmotor und Kraftstoffeinspritzsystem zur Steuerung eines Einspritzstroms

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010149416A1 (de) * 2009-06-26 2010-12-29 Robert Bosch Gmbh Steuervorrichtung für einen elektrischen hochstromverbraucher, verfahren zum betreiben derselben, computerprogrammprodukt
EP2365201A3 (de) * 2010-03-09 2013-10-30 Hitachi Automotive Systems, Ltd. Kraftstoffeinspritzsystem für eine Brennkraftmaschine und Verfahren zur Steuerung eines Kraftstoffeinspritzsystems einer Brennkraftmaschine
US20180328304A1 (en) * 2017-05-10 2018-11-15 Ford Global Technologies, Llc Method and system for characterizing a port fuel injector
WO2019215034A1 (en) * 2018-05-08 2019-11-14 Delphi Technologies Ip Limited Method to determine the operating resistance of an electrical harness connecting an ecu to a solenoid controlled valve

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0893594A2 (de) * 1997-07-22 1999-01-27 Isuzu Motors Limited Kraftstoffeinspritzsteuervorrichtung
US5992391A (en) * 1997-06-26 1999-11-30 Hitachi, Ltd. Electromagnetic fuel injector and control method thereof
EP0971115A2 (de) * 1998-07-08 2000-01-12 Isuzu Motors Limited Kraftstoffeinspritzsystem mit Verteilerleitung
EP1072779A2 (de) * 1999-07-28 2001-01-31 Hitachi, Ltd. Kraftstoffeinspritzventil und Brennkraftmaschine
US6532940B1 (en) * 2000-04-28 2003-03-18 Mitsubishi Denki Kabushiki Kaisha Fuel injection control system for cylinder injection type internal combustion engine
US20050126543A1 (en) 2003-11-25 2005-06-16 Alberto Manzone Drive device for electrical injectors of an internal combustion engine common rail fuel injection system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5992391A (en) * 1997-06-26 1999-11-30 Hitachi, Ltd. Electromagnetic fuel injector and control method thereof
EP0893594A2 (de) * 1997-07-22 1999-01-27 Isuzu Motors Limited Kraftstoffeinspritzsteuervorrichtung
EP0971115A2 (de) * 1998-07-08 2000-01-12 Isuzu Motors Limited Kraftstoffeinspritzsystem mit Verteilerleitung
EP1072779A2 (de) * 1999-07-28 2001-01-31 Hitachi, Ltd. Kraftstoffeinspritzventil und Brennkraftmaschine
US6532940B1 (en) * 2000-04-28 2003-03-18 Mitsubishi Denki Kabushiki Kaisha Fuel injection control system for cylinder injection type internal combustion engine
US20050126543A1 (en) 2003-11-25 2005-06-16 Alberto Manzone Drive device for electrical injectors of an internal combustion engine common rail fuel injection system

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010149416A1 (de) * 2009-06-26 2010-12-29 Robert Bosch Gmbh Steuervorrichtung für einen elektrischen hochstromverbraucher, verfahren zum betreiben derselben, computerprogrammprodukt
CN102483022A (zh) * 2009-06-26 2012-05-30 罗伯特·博世有限公司 大电流耗电器用控制装置和其运行方法及计算机程序产品
EP2365201A3 (de) * 2010-03-09 2013-10-30 Hitachi Automotive Systems, Ltd. Kraftstoffeinspritzsystem für eine Brennkraftmaschine und Verfahren zur Steuerung eines Kraftstoffeinspritzsystems einer Brennkraftmaschine
US8783230B2 (en) 2010-03-09 2014-07-22 Hitachi Automotive Systems, Ltd. Fuel injection system for internal-combustion engine and method of controlling fuel injection system for internal-combustion engine
US20180328304A1 (en) * 2017-05-10 2018-11-15 Ford Global Technologies, Llc Method and system for characterizing a port fuel injector
US10760518B2 (en) * 2017-05-10 2020-09-01 Ford Global Technologies, Llc Method and system for characterizing a port fuel injector
WO2019215034A1 (en) * 2018-05-08 2019-11-14 Delphi Technologies Ip Limited Method to determine the operating resistance of an electrical harness connecting an ecu to a solenoid controlled valve
CN112105810A (zh) * 2018-05-08 2020-12-18 德尔福知识产权有限公司 确定将ecu连接到电磁阀的电气线束的工作电阻的方法
US11230986B2 (en) 2018-05-08 2022-01-25 Delphi Technologies Ip Limited Method to determine the operating resistance of an electrical harness connecting an ECU to a solenoid controlled valve
CN112105810B (zh) * 2018-05-08 2022-09-02 德尔福知识产权有限公司 确定将ecu连接到电磁阀的电气线束的工作电阻的方法

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