WO2015093219A1 - Glow plug failure diagnostic method and glow plug failure diagnostic apparatus - Google Patents

Glow plug failure diagnostic method and glow plug failure diagnostic apparatus Download PDF

Info

Publication number
WO2015093219A1
WO2015093219A1 PCT/JP2014/080608 JP2014080608W WO2015093219A1 WO 2015093219 A1 WO2015093219 A1 WO 2015093219A1 JP 2014080608 W JP2014080608 W JP 2014080608W WO 2015093219 A1 WO2015093219 A1 WO 2015093219A1
Authority
WO
WIPO (PCT)
Prior art keywords
glow plug
temperature
voltage
shunt
shunt resistor
Prior art date
Application number
PCT/JP2014/080608
Other languages
French (fr)
Japanese (ja)
Inventor
友洋 中村
須田　敬久
Original Assignee
ボッシュ株式会社
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 ボッシュ株式会社 filed Critical ボッシュ株式会社
Priority to JP2015553439A priority Critical patent/JP6188170B2/en
Publication of WO2015093219A1 publication Critical patent/WO2015093219A1/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P19/00—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition
    • F02P19/02—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P17/00—Testing of ignition installations, e.g. in combination with adjusting; Testing of ignition timing in compression-ignition engines
    • F02P17/12—Testing characteristics of the spark, ignition voltage or current
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P19/00—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition
    • F02P19/02—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs
    • F02P19/025—Incandescent ignition, e.g. during starting of internal combustion engines; Combination of incandescent and spark ignition electric, e.g. layout of circuits of apparatus having glowing plugs with means for determining glow plug temperature or glow plug resistance

Definitions

  • the present invention relates to a glow plug failure diagnosis method and a glow plug failure diagnosis device used in an internal combustion engine, and more particularly to a device that improves the reliability and accuracy of failure diagnosis.
  • JP 2010-180812 (page 7-13, FIG. 1 to FIG. 3)
  • the conventional glow plug fault diagnosis as described above has a problem that it is difficult to obtain satisfactory reliability as described below. That is, the conventional glow plug failure determination described above is performed based on whether or not the current of the glow plug exceeds a threshold at which a glow plug failure can be determined. In consideration of the temperature range in which the glow plug control device is used, for example, ⁇ 40 ° C. to 105 ° C., one suitable value is set based on the test result and simulation result.
  • the present invention has been made in view of the above circumstances, and is a glow plug that enables highly reliable failure diagnosis of a glow plug without being affected by variations in the temperature characteristics of the glow plug and the temperature characteristics of the control circuit.
  • a failure diagnosis method and a glow plug failure diagnosis apparatus are provided.
  • a fault diagnosis method for a glow plug includes: A glow plug is provided in series with a current control semiconductor element and a shunt resistor between the battery and the ground, and the operation of the current control semiconductor element to enable current control of the glow plug.
  • An arithmetic control unit configured to be controllable and a measurement circuit configured to be able to supply the voltage of the shunt resistor to the arithmetic control unit are provided in the same casing together with the shunt resistor,
  • a glow plug fault diagnostic method in a glow plug fault diagnostic apparatus configured to be used for recognizing the voltage and current of the glow plug by the arithmetic control unit, the voltage across the shunt resistor, The voltage of the shunt resistor obtained through the measurement circuit is corrected based on the temperature in the casing to obtain a shunt correction voltage, and a predetermined standard value of the shunt resistor is set to the temperature in the casing.
  • a glow plug failure diagnosis apparatus comprises: A glow plug is provided in series with a current control semiconductor element and a shunt resistor between the battery and the ground, and the operation of the current control semiconductor element to enable current control of the glow plug.
  • An arithmetic control unit configured to be controllable and a measurement circuit configured to be able to supply the voltage of the shunt resistor to the arithmetic control unit are provided in the same casing together with the shunt resistor,
  • a glow plug fault diagnosis device configured such that the voltage across the shunt resistor is used for recognition of the voltage and current of the glow plug by the arithmetic control unit,
  • the arithmetic control unit is The voltage of the shunt resistor obtained through the measurement circuit is corrected based on the temperature in the casing and calculated as a shunt correction voltage, and a predetermined standard value of the shunt resistor is calculated in the casing.
  • the shunt correction voltage is divided by the shunt correction resistance value, and the division result is a glow current that is the current of the glow plug, When the glow current exceeds a predetermined threshold, it is determined that the glow plug has failed.
  • the glow current corrected in accordance with the temperature inside the housing provided with the glow plug drive circuit and the like is obtained, the temperature characteristics of the glow plug and the temperature characteristics of the control circuit are varied. Therefore, it is possible to diagnose a failure of the glow plug with high reliability without being influenced by the above, and to provide an apparatus with high reliability.
  • FIG. 1 It is a block diagram which shows the structural example of the glow plug failure diagnostic apparatus in embodiment of this invention. It is a subroutine flowchart which shows the procedure of the glow plug fault diagnostic process performed in the glow plug fault diagnostic apparatus shown by FIG.
  • the glow plug failure diagnosis device according to the embodiment of the present invention is realized by a glow plug drive control device, and FIG. 1 shows an example of the configuration of the glow plug drive control device.
  • a glow plug drive control device hereinafter referred to as “GCU” 100 that realizes a glow plug failure diagnosis device according to an embodiment of the present invention will be described with reference to FIG.
  • the GCU 100 is roughly divided into an energization drive circuit 51, a measurement circuit 52, and an arithmetic control unit (indicated as “CPU” in FIG. 1) 53. .
  • the energization drive circuit 51, the measurement circuit 52, and the calculation control unit 53 are housed in an appropriate housing (not shown).
  • the energization drive circuit 51 is configured such that energization control of the glow plug 1 is possible with the energization control semiconductor element 2 and the shunt resistor 3 as main components. That is, first, for example, a MOS FET or the like is used for the energization control semiconductor element 2, the drain is on the positive side of the vehicle battery 4, and the source is on the positive side of the glow plug 1 via the shunt resistor 3. The negative side of the glow plug 1 is connected to ground. In addition, a control signal from the arithmetic control unit 53 is applied to the gate of the energization control semiconductor element 2 so that conduction and non-conduction of the energization control semiconductor element 2 can be controlled.
  • a MOS FET or the like is used for the energization control semiconductor element 2
  • the drain is on the positive side of the vehicle battery 4
  • the source is on the positive side of the glow plug 1 via the shunt resistor 3.
  • the negative side of the glow plug 1 is connected
  • the measurement circuit 52 includes the operational amplifier 5, the analog / digital converter (indicated as "A / D" in FIG. 1) 6, and the temperature detection element 7 as main components, and the voltage in the shunt resistor 3 is measured.
  • the descent is configured to be supplied to the arithmetic control unit 53 as a digital signal. That is, first, a voltage across the shunt resistor 3 is input to the operational amplifier 5, and the input voltage is amplified to a voltage suitable for the input of the analog / digital converter 6 in the next stage. Is output. The output voltage of the operational amplifier 5 is inputted to the arithmetic control unit 53 as a digital value by the analog / digital converter 6.
  • the temperature detecting element 7 is exposed to the temperature in the GCU 100 (in other words, in the casing), in other words, the electronic components in the GCU 100 such as the shunt resistor 3, the operational amplifier 5, and the analog / digital converter 6.
  • the electronic components in the GCU 100 such as the shunt resistor 3, the operational amplifier 5, and the analog / digital converter 6.
  • NTC negative temperature coefficient
  • the output signal of the temperature detection element 7 is input to the arithmetic control unit 53, converted into a digital signal by the arithmetic control unit 53, and used for a later-described glow plug failure diagnosis process executed by the arithmetic control unit 53. It is like that.
  • the arithmetic control unit 53 includes, for example, a storage element (not shown) such as a RAM or a ROM centering on a microcomputer (not shown) or an ASIC (Application Specific Integrated Circuit) having a known or well-known configuration. And an interface circuit (not shown) for outputting a control signal for the energization control semiconductor element 2 as a main component.
  • a storage element such as a RAM or a ROM centering on a microcomputer (not shown) or an ASIC (Application Specific Integrated Circuit) having a known or well-known configuration.
  • an interface circuit (not shown) for outputting a control signal for the energization control semiconductor element 2 as a main component.
  • the glow plug 1 in the embodiment of the present invention is driven and controlled by so-called closed loop control. Specifically, first, the arithmetic control unit 53 determines the shunt resistor 3 from the magnitude of the voltage drop of the shunt resistor 3 input by the measurement circuit 52 and the resistance value of the shunt resistor 3 that has been grasped in advance. The flowing current is calculated as the current flowing through the glow plug 1. Then, the actual resistance value of the glow plug 1 is obtained by dividing the actual applied voltage of the glow plug 1 by the calculated current value.
  • the voltage applied to the glow plug 1 is obtained by subtracting the voltage drop in the energization control semiconductor element 2 and the voltage drop in the shunt resistor 3 from the voltage value of the vehicle battery 4.
  • the voltage drop of the energization control semiconductor element 2 is grasped in advance and set as a constant.
  • the arithmetic control unit 53 stores the correlation between the resistance value of the glow plug 1 and the temperature of the glow plug 1 (glow plug temperature), for example, as a resistance / temperature correlation map, and is obtained as described above.
  • the glow plug temperature with respect to the resistance value of the glow plug 1 is obtained from the resistance-temperature correlation map.
  • the arithmetic control unit 53 is instructed by the engine control electronic control unit (indicated as “ECU” in FIG. 1) 200 to set the temperature of the glow plug 1 and the voltage applied to the base glow plug 1. It has become. This set temperature is determined in accordance with the operating state of the engine in the electronic control unit 200 for engine control.
  • the glow plug applied voltage as a base is based on the electrical characteristics of the glow plug 1 that are grasped in advance in the electronic control unit 200 for engine control in accordance with each glow plug set temperature and the operating state of the engine. It is determined using a set arithmetic expression, a map, or the like.
  • the engine control electronic control unit 200 is calculated from the correlation between the glow plug set temperature input from the engine control electronic control unit 200 and the glow plug temperature obtained as described above.
  • a correction voltage for the glow plug applied voltage which is the base input from, is obtained.
  • the glow plug applied voltage as a base is corrected by the correction voltage, and the final applied voltage of the glow plug 1 is obtained.
  • drive control of the energization control semiconductor element 2 by the arithmetic control unit 53 is performed by PWM control.
  • the voltage applied to the glow plug 1 is corrected as described above.
  • the duty of the PWM signal applied to the energization control semiconductor element 2 is calculated by an arithmetic process so that the required voltage is obtained, and is applied to the energization control semiconductor element 2 so that conduction or non-conduction is achieved. To be controlled.
  • the glow plug failure diagnosis process executed by the arithmetic control unit 53 will be described with reference to the subroutine flowchart shown in FIG.
  • the subroutine flowchart shown in FIG. 2 is one of various subroutine processes executed in the arithmetic control unit 53 together with the energization drive control of the glow plug 1 executed in the arithmetic control unit 53 as in the prior art. It is.
  • a voltage (shunt voltage) between both terminals of the shunt resistor 3 is read (see step S102 in FIG. 2). That is, the voltage of the shunt resistor 3 is taken into the arithmetic control unit 53 as a digital value via the operational amplifier 5 and the analog / digital converter 6 and stored and held in an appropriate storage area.
  • the temperature in the GCU 100 (the temperature in the housing) is read (see step S104 in FIG. 2). That is, the output signal of the temperature detection element 7 is taken into the arithmetic control unit 53 and stored and held in an appropriate storage area as the temperature in the casing.
  • the resistance correction coefficient Kr and the amplification / conversion correction coefficient Kd are calculated (see step S106 in FIG. 2).
  • the resistance correction coefficient Kr is a correction coefficient used when calculating and calculating the actual resistance value of the shunt resistor 3 considering the temperature change in the casing as will be described later
  • the amplification / conversion correction coefficient Kd is the casing. This is a correction coefficient used when calculating and calculating a correct output value of the analog / digital converter 6 in consideration of changes in internal temperature, as will be described later.
  • the amplification / conversion correction coefficient Kd includes fluctuations in the output signal of the operational amplifier 5 due to temperature changes in the housing.
  • the resistance value of the shunt resistor 3 used for calculating the actual resistance value of the glow plug 1 and the output values of the operational amplifier 5 and the analog / digital converter 6 are In view of the change depending on the temperature, the standard resistance value of the shunt resistor 3 and the standard value of the output value of the analog / digital converter 6 are corrected according to the temperature in the housing, and the temperature in the housing is taken into consideration. In other words, the resistance value of the shunt resistor 3 and the output value of the analog / digital converter 6 corresponding to the temperature in the housing are obtained and used for calculating the actual resistance value of the glow plug 1. Thus, the actual resistance value of the glow plug 1 can be calculated accurately.
  • the resistance value (shunt correction resistance value) Rs of the shunt resistor 3 in consideration of the temperature in the housing can be obtained by the following formula 1 according to the general characteristic of the resistance element with respect to the temperature change.
  • Rc is a resistance value (standard resistance value) of the shunt resistor 3 at a standard temperature (for example, 24 ° C.).
  • TCR is a resistance correction coefficient Kr.
  • ⁇ T is a difference between the above-described standard temperature and the temperature inside the casing obtained in step S104.
  • the sign ⁇ in the above equation 1 is alternatively selected depending on whether the temperature coefficient of the shunt resistor 3 is a negative temperature coefficient or a positive temperature coefficient.
  • the resistance correction coefficient Kr changes depending on the temperature in the casing.
  • the resistance correction coefficient Kr corresponds to the temperature in the casing acquired in the previous step S104 by the resistance correction coefficient map or the resistance correction coefficient calculation formula.
  • a resistance correction coefficient Kr is obtained. That is, the resistance correction coefficient map is configured in advance so that the resistance correction coefficient Kr with respect to various in-chassis temperatures can be read out using the in-chassis temperature as an input parameter based on tests and simulation results. These are stored in advance in appropriate storage areas.
  • the resistance correction coefficient calculation expression is an expression set in advance so that the resistance correction coefficient Kr can be calculated based on a test or simulation result using the temperature in the housing as an argument.
  • the output signal of the analog / digital converter 6 in consideration of the temperature in the housing includes the change in the amplification factor and the input / output offset accompanying the temperature change in the housing of the operational amplifier 5 and is obtained by the following equation 2.
  • the amplification factor including both the operational amplifier 5 and the analog / digital converter 6 is set to 1. Therefore, the voltage value obtained by the following equation 2 is the voltage across the shunt resistor 3 via the operational amplifier 5 and the analog / digital converter 6.
  • VVT f (Tu) ⁇ Vs ... Equation 2
  • VT is an analog voltage value (shunt correction voltage) corresponding to the digital output value of the analog / digital converter 6 in consideration of the temperature in the housing.
  • Vs is the voltage across the shunt resistor 3 read in step S102.
  • f (Tu) is the voltage across the shunt resistor 3 even if the digital output value of the analog-to-digital converter 6 including the characteristic fluctuation of the operational amplifier 5 due to the change in the temperature inside the casing occurs.
  • the amplification / conversion correction coefficient Kd is set based on the test result and the simulation result so that the temperature inside the casing is an input parameter so that the original correct value can be obtained.
  • the shunt correction resistance value and the shunt are obtained using the resistance correction coefficient Kr and the amplification / conversion correction coefficient Kd.
  • the correction voltage is calculated (see step S108 in FIG. 2). That is, first, the shunt correction resistance value Rs is obtained by the above equation 1. Next, the shunt correction voltage VT is obtained by the above equation 2.
  • the current flowing through the glow plug 1 is calculated (see step S110 in FIG. 2). That is, the current (glow current) Ig that flows through the glow plug 1 is also a current that flows through the shunt resistor 3, and thus can be obtained by the following equation (3).
  • VT is the shunt correction voltage obtained in step S108
  • Rs is the shunt correction resistance value obtained in step S108.
  • failure determination of the glow plug is performed based on the above-described glow current Ig. That is, it is determined whether or not the glow current Ig exceeds a predetermined threshold value K. When it is determined that the glow current Ig does not exceed the predetermined threshold value (in the case of NO), it is determined to be normal (step of FIG. 2). S114), a series of processing is completed, the process returns to the main routine (not shown), and energization control of the glow plug 1 is continued.
  • step S112 when it is determined in step S112 that the glow current Ig exceeds the predetermined threshold K (in the case of YES), it is determined that the glow plug 1 is in failure (see step S116 in FIG. 2), and the main not shown.
  • an alarm process such as an alarm display, or a process of stopping energization control to the glow plug 1 is executed as necessary.
  • the threshold value K in step S112 is the most suitable value based on test results and simulation results in consideration of the temperature range in which the glow plug drive control device 100 is used, for example, ⁇ 40 ° C. to 105 ° C. Is set as.
  • the glow current Ig is corrected by the voltage VT and the resistance value Rs across the shunt resistor 3 corrected in accordance with the casing temperature of the glow plug drive control device 100. Therefore, unlike the conventional case, it is reliably avoided that the threshold value K itself is not appropriate as a criterion for determining the suitability of the glow current Ig.
  • the determination in step S112 is the same as the conventional case. In contrast, it is highly accurate and reliable.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)

Abstract

To highly reliably diagnose failures of glow plugs without being affected by variance of temperature characteristics of the glow plugs and variance of temperature characteristics of control circuits. A shunt resistor (3) voltage obtained by means of a measuring circuit (52) is corrected to be a corrected shunt voltage on the basis of a temperature inside of a GCU (100), a predetermined reference value of the shunt resistor (3) is corrected to be a corrected shunt resistance value on the basis of a temperature of the GCU (100), the corrected shunt voltage is divided by the corrected shunt resistance value, a result of the division is set as a glow current, i.e., a current of a glow plug (1), and when the result is exceeding a predetermined threshold value, it is determined that the glow plug (1) has a failure.

Description

グロープラグの故障診断方法及びグロープラグ故障診断装置Glow plug fault diagnosis method and glow plug fault diagnosis device
 　本発明は、内燃機関において用いられるグロープラグの故障診断方法及びグロープラグ故障診断装置に係り、特に、故障診断の信頼性、精度の向上等を図ったものに関する。 The present invention relates to a glow plug failure diagnosis method and a glow plug failure diagnosis device used in an internal combustion engine, and more particularly to a device that improves the reliability and accuracy of failure diagnosis.
 　ディーゼルエンジンなどの内燃機関に用いられるグロープラグの動作状態、特に、その温度はディーゼルエンジン等の始動性などに大きな影響を与えることがあるため、高い精度での温度制御が求められると共に、信頼性の高いグロープラグの故障診断が求められ、これに応えるべく、種々の制御方法、装置が提案、実用化されていることは良く知られている通りである（例えば、特許文献１等参照）。
 　かかるグロープラグ診断の基本的な手法としては、例えば、グロープラグの電流を検出し、その値が所定の閾値を超えている場合に故障と判断する手法が一般的である。 The operating status of glow plugs used in internal combustion engines such as diesel engines, especially their temperature, can have a significant impact on the startability of diesel engines, etc., so high-precision temperature control is required and reliability Therefore, it is well known that various control methods and devices have been proposed and put into practical use in order to respond to the failure diagnosis of high glow plugs (see, for example, Patent Document 1).
As a basic method of such glow plug diagnosis, for example, a method of detecting a glow plug current and determining a failure when the value exceeds a predetermined threshold is common.
特開２０１０－１８０８１２号公報（第７－１３頁、図１－図３）JP 2010-180812 (page 7-13, FIG. 1 to FIG. 3)
 　しかしながら、上述のような従来のグロープラグの故障診断は、次述するように必ずしも満足する信頼性が得難いという問題がある。
 　すなわち、上述の従来のグロープラグの故障判断は、グロープラグの電流が、グロープラグの故障と判断できる閾値を超えているか否かによって行われるものであるが、故障判断の基準となる閾値は、グロープラグ制御装置が用いられる温度範囲、例えば、－４０℃～１０５℃を考慮して、試験結果やシミュレーション結果を基に好適な一つの値を設定して用いるものとなっている。 However, the conventional glow plug fault diagnosis as described above has a problem that it is difficult to obtain satisfactory reliability as described below.
That is, the conventional glow plug failure determination described above is performed based on whether or not the current of the glow plug exceeds a threshold at which a glow plug failure can be determined. In consideration of the temperature range in which the glow plug control device is used, for example, −40 ° C. to 105 ° C., one suitable value is set based on the test result and simulation result.
 　ところが、上述のようにして定められた好適な閾値であっても、実際には、個々のグロープラグの温度特性や制御回路の温度特性ばらつきに十分対応できるものではなく、なかには故障判断の閾値が適切ではなく、誤診断となる場合も皆無ではない。 However, even with a suitable threshold value determined as described above, in reality, it cannot sufficiently cope with variations in temperature characteristics of individual glow plugs and temperature characteristics of control circuits. It is not appropriate, and there are no cases of misdiagnosis.
 　本発明は、上記実状に鑑みてなされたもので、グロープラグの温度特性や制御回路の温度特性のばらつきに影響されることなく、信頼性の高いグロープラグの故障診断を可能とするグロープラグの故障診断方法及びグロープラグ故障診断装置を提供するものである。 The present invention has been made in view of the above circumstances, and is a glow plug that enables highly reliable failure diagnosis of a glow plug without being affected by variations in the temperature characteristics of the glow plug and the temperature characteristics of the control circuit. A failure diagnosis method and a glow plug failure diagnosis apparatus are provided.
 　上記本発明の目的を達成するため、本発明に係るグロープラグの故障診断方法は、
 　グロープラグが、バッテリとグランドとの間に、通電制御用半導体素子及びシャント抵抗器と共に直列接続されて設けられる一方、前記グロープラグの通電制御を可能とするために前記通電制御用半導体素子の動作制御可能に構成されてなる演算制御部と、前記シャント抵抗器の電圧を前記演算制御部へ供給可能に構成されてなる計測回路とが、前記シャント抵抗器と共に同一の筐体内に設けられ、前記シャント抵抗器の両端の電圧が、前記演算制御部による前記グロープラグの電圧、電流の認識に供されるよう構成されてなるグロープラグ故障診断装置におけるグロープラグの故障診断方法であって、
 　前記計測回路を介して得られた前記シャント抵抗器の電圧を、前記筐体内の温度に基づいて補正してシャント補正電圧とすると共に、前記シャント抵抗器の所定の標準値を前記筐体内の温度に基づいて補正してシャント補正抵抗値とし、
 　前記シャント補正電圧を前記シャント補正抵抗値で除し、その除算結果を前記グロープラグの電流であるグロー電流とし、
 　前記グロー電流が所定の閾値を越える場合に、前記グロープラグの故障と判断するよう構成されてなるものである。
 　また、上記本発明の目的を達成するため、本発明に係るグロープラグ故障診断装置は、
 　グロープラグが、バッテリとグランドとの間に、通電制御用半導体素子及びシャント抵抗器と共に直列接続されて設けられる一方、前記グロープラグの通電制御を可能とするために前記通電制御用半導体素子の動作制御可能に構成されてなる演算制御部と、前記シャント抵抗器の電圧を前記演算制御部へ供給可能に構成されてなる計測回路とが、前記シャント抵抗器と共に同一の筐体内に設けられ、前記シャント抵抗器の両端の電圧が、前記演算制御部による前記グロープラグの電圧、電流の認識に供されるよう構成されてなるグロープラグ故障診断装置であって、
 　前記演算制御部は、
 　前記計測回路を介して得られた前記シャント抵抗器の電圧を、前記筐体内の温度に基づいて補正してシャント補正電圧として算出すると共に、前記シャント抵抗器の所定の標準値を前記筐体内の温度に基づいて補正してシャント補正抵抗値として算出し、
 　前記シャント補正電圧を前記シャント補正抵抗値で除し、その除算結果を前記グロープラグの電流であるグロー電流とし、
 　前記グロー電流が所定の閾値を越える場合に、前記グロープラグの故障と判断するよう構成されてなるものである。 In order to achieve the above object of the present invention, a fault diagnosis method for a glow plug according to the present invention includes:
A glow plug is provided in series with a current control semiconductor element and a shunt resistor between the battery and the ground, and the operation of the current control semiconductor element to enable current control of the glow plug. An arithmetic control unit configured to be controllable and a measurement circuit configured to be able to supply the voltage of the shunt resistor to the arithmetic control unit are provided in the same casing together with the shunt resistor, A glow plug fault diagnostic method in a glow plug fault diagnostic apparatus configured to be used for recognizing the voltage and current of the glow plug by the arithmetic control unit, the voltage across the shunt resistor,
The voltage of the shunt resistor obtained through the measurement circuit is corrected based on the temperature in the casing to obtain a shunt correction voltage, and a predetermined standard value of the shunt resistor is set to the temperature in the casing. Is corrected to the shunt correction resistance value based on
The shunt correction voltage is divided by the shunt correction resistance value, and the division result is a glow current that is the current of the glow plug,
When the glow current exceeds a predetermined threshold, it is determined that the glow plug has failed.
In order to achieve the above object of the present invention, a glow plug failure diagnosis apparatus according to the present invention comprises:
A glow plug is provided in series with a current control semiconductor element and a shunt resistor between the battery and the ground, and the operation of the current control semiconductor element to enable current control of the glow plug. An arithmetic control unit configured to be controllable and a measurement circuit configured to be able to supply the voltage of the shunt resistor to the arithmetic control unit are provided in the same casing together with the shunt resistor, A glow plug fault diagnosis device configured such that the voltage across the shunt resistor is used for recognition of the voltage and current of the glow plug by the arithmetic control unit,
The arithmetic control unit is
The voltage of the shunt resistor obtained through the measurement circuit is corrected based on the temperature in the casing and calculated as a shunt correction voltage, and a predetermined standard value of the shunt resistor is calculated in the casing. Correct based on temperature and calculate as shunt correction resistance value,
The shunt correction voltage is divided by the shunt correction resistance value, and the division result is a glow current that is the current of the glow plug,
When the glow current exceeds a predetermined threshold, it is determined that the glow plug has failed.
 　本発明によれば、グロープラグの駆動回路等が設けられた筐体内の温度に対応して補正されたグロー電流が得られるようにしたので、グロープラグの温度特性や制御回路の温度特性のばらつきに影響されることなく、信頼性の高いグロープラグの故障診断が可能となり、信頼性の高い装置を提供することができるという効果を奏するものである。 According to the present invention, since the glow current corrected in accordance with the temperature inside the housing provided with the glow plug drive circuit and the like is obtained, the temperature characteristics of the glow plug and the temperature characteristics of the control circuit are varied. Therefore, it is possible to diagnose a failure of the glow plug with high reliability without being influenced by the above, and to provide an apparatus with high reliability.
本発明の実施の形態におけるグロープラグ故障診断装置の構成例を示す構成図である。It is a block diagram which shows the structural example of the glow plug failure diagnostic apparatus in embodiment of this invention. 図１に示されたグロープラグ故障診断装置において実行されるグロープラグ故障診断処理の手順を示すサブルーチンフローチャートである。It is a subroutine flowchart which shows the procedure of the glow plug fault diagnostic process performed in the glow plug fault diagnostic apparatus shown by FIG.
 　以下、本発明の実施の形態について、図１及び図２を参照しつつ説明する。
 　なお、以下に説明する部材、配置等は本発明を限定するものではなく、本発明の趣旨の範囲内で種々改変することができるものである。
 　最初に、本発明の実施の形態におけるグロープラグ故障診断装置は、グロープラグ駆動制御装置によって実現されるものとなっており、図１には、かかるグロープラグ駆動制御装置の構成例が示されており、以下、同図を参照しつつ、本発明の実施の形態におけるグロープラグ故障診断装置を実現するグロープラグ駆動制御装置（以下「ＧＣＵ」と称する）１００について説明する。
 　本発明の実施の形態におけるＧＣＵ１００は、通電駆動回路５１と、計測回路５２と、演算制御部（図１においては「ＣＰＵ」と表記）５３とに大別されて構成されたものとなっている。なお、これら通電駆動回路５１、計測回路５２、及び、演算制御部５３は、適宜な筐体（図示せず）内に収納されるものとなっている。 Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2.
The members and arrangements described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.
First, the glow plug failure diagnosis device according to the embodiment of the present invention is realized by a glow plug drive control device, and FIG. 1 shows an example of the configuration of the glow plug drive control device. Hereinafter, a glow plug drive control device (hereinafter referred to as “GCU”) 100 that realizes a glow plug failure diagnosis device according to an embodiment of the present invention will be described with reference to FIG.
The GCU 100 according to the embodiment of the present invention is roughly divided into an energization drive circuit 51, a measurement circuit 52, and an arithmetic control unit (indicated as “CPU” in FIG. 1) 53. . The energization drive circuit 51, the measurement circuit 52, and the calculation control unit 53 are housed in an appropriate housing (not shown).
 　通電駆動回路５１は、通電制御用半導体素子２と、シャント抵抗器３とを主たる構成要素として、グロープラグ１の通電制御が可能に構成されたものとなっている。
 　すなわち、まず、通電制御用半導体素子２は、例えば、ＭＯＳ　ＦＥＴなどが用いられ、そのドレインは、車両用バッテリ４の正極に、ソースは、シャント抵抗器３を介してグロープラグ１の正極側に接続され、グロープラグ１の負極側は、アースに接続されたものとなっている。また、通電制御用半導体素子２のゲートには、演算制御部５３からの制御信号が印加されるようになっており、通電制御用半導体素子２の導通、非導通が制御可能となっている。 The energization drive circuit 51 is configured such that energization control of the glow plug 1 is possible with the energization control semiconductor element 2 and the shunt resistor 3 as main components.
That is, first, for example, a MOS FET or the like is used for the energization control semiconductor element 2, the drain is on the positive side of the vehicle battery 4, and the source is on the positive side of the glow plug 1 via the shunt resistor 3. The negative side of the glow plug 1 is connected to ground. In addition, a control signal from the arithmetic control unit 53 is applied to the gate of the energization control semiconductor element 2 so that conduction and non-conduction of the energization control semiconductor element 2 can be controlled.
 　一方、計測回路５２は、演算増幅器５と、アナログ・ディジタル変換器（図１においては「Ａ／Ｄ」と表記）６と、温度検出素子７とを主たる構成要素として、シャント抵抗器３における電圧降下がディジタル信号として演算制御部５３に供給可能に構成されたものとなっている。
 　すなわち、まず、演算増幅器５には、シャント抵抗器３の両端の電圧が入力されるようになっており、その入力電圧は、次段のアナログ・ディジタル変換器６の入力に適した電圧に増幅され、出力されるようになっている。そして、演算増幅器５の出力電圧は、アナログ・ディジタル変換器６によりディジタル値として演算制御部５３に入力されるようになっている。 On the other hand, the measurement circuit 52 includes the operational amplifier 5, the analog / digital converter (indicated as "A / D" in FIG. 1) 6, and the temperature detection element 7 as main components, and the voltage in the shunt resistor 3 is measured. The descent is configured to be supplied to the arithmetic control unit 53 as a digital signal.
That is, first, a voltage across the shunt resistor 3 is input to the operational amplifier 5, and the input voltage is amplified to a voltage suitable for the input of the analog / digital converter 6 in the next stage. Is output. The output voltage of the operational amplifier 5 is inputted to the arithmetic control unit 53 as a digital value by the analog / digital converter 6.
 　温度検出素子７は、ＧＣＵ１００内（換言すれば、筐体内）の温度、換言すれば、シャント抵抗器３、演算増幅器５、アナログ・ディジタル変換器６等のＧＣＵ１００内の電子部品が晒されている雰囲気温度（周囲温度）を検出するため、ＧＣＵ１００内の適宜な位置に設けられているものである。かかる温度検出素子７としては、具体的には、例えば、ＮＴＣ(negative temperature coefficient)などが好適である。
 　この温度検出素子７の出力信号は、演算制御部５３に入力され、演算制御部５３においてディジタル信号に変換されて、演算制御部５３において実行される後述のグロープラグの故障診断処理に供されるようになっている。 The temperature detecting element 7 is exposed to the temperature in the GCU 100 (in other words, in the casing), in other words, the electronic components in the GCU 100 such as the shunt resistor 3, the operational amplifier 5, and the analog / digital converter 6. In order to detect the atmospheric temperature (ambient temperature), it is provided at an appropriate position in the GCU 100. Specifically, for example, NTC (negative temperature coefficient) is suitable as the temperature detecting element 7.
The output signal of the temperature detection element 7 is input to the arithmetic control unit 53, converted into a digital signal by the arithmetic control unit 53, and used for a later-described glow plug failure diagnosis process executed by the arithmetic control unit 53. It is like that.
 　演算制御部５３は、例えば、公知・周知の構成を有してなるマイクロコンピュータ（図示せず）やＡＳＩＣ(Application Specific Integrated Circuit)を中心に、ＲＡＭやＲＯＭ等の記憶素子（図示せず）を有すると共に、先の通電制御用半導体素子２へ対する制御信号を出力するためのインターフェイス回路（図示せず）などを主たる構成要素として構成されたものとなっているものである。 The arithmetic control unit 53 includes, for example, a storage element (not shown) such as a RAM or a ROM centering on a microcomputer (not shown) or an ASIC (Application Specific Integrated Circuit) having a known or well-known configuration. And an interface circuit (not shown) for outputting a control signal for the energization control semiconductor element 2 as a main component.
 　ここで、本発明の実施の形態におけるグロープラグ１は、いわゆる閉ループ制御により駆動制御されるものとなっている。
 　具体的には、まず、演算制御部５３において、計測回路５２により入力されたシャント抵抗器３の電圧降下の大きさと、予め把握されているシャント抵抗器３の抵抗値とからシャント抵抗器３を流れる電流が、グロープラグ１を流れる電流として演算算出される。そして、グロープラグ１の実際の印加電圧を、上述の算出された電流値で除することでグロープラグ１の実際の抵抗値が求められる。 Here, the glow plug 1 in the embodiment of the present invention is driven and controlled by so-called closed loop control.
Specifically, first, the arithmetic control unit 53 determines the shunt resistor 3 from the magnitude of the voltage drop of the shunt resistor 3 input by the measurement circuit 52 and the resistance value of the shunt resistor 3 that has been grasped in advance. The flowing current is calculated as the current flowing through the glow plug 1. Then, the actual resistance value of the glow plug 1 is obtained by dividing the actual applied voltage of the glow plug 1 by the calculated current value.
 　ここで、グロープラグ１の印加電圧は、車両用バッテリ４の電圧値から、通電制御用半導体素子２における電圧降下、シャント抵抗器３の電圧降下を減算したものとして求められる。通電制御用半導体素子２の電圧降下は、予め把握されて定数として設定されたものが用いられるようになっている。 Here, the voltage applied to the glow plug 1 is obtained by subtracting the voltage drop in the energization control semiconductor element 2 and the voltage drop in the shunt resistor 3 from the voltage value of the vehicle battery 4. The voltage drop of the energization control semiconductor element 2 is grasped in advance and set as a constant.
 　演算制御部５３には、グロープラグ１の抵抗値とグロープラグ１の温度（グロープラグ温度）との相関関係が、例えば、抵抗・温度相関マップとして記憶されており、上述のようにして求められたグロープラグ１の抵抗値に対するグロープラグ温度がその抵抗・温度相関マップから求められる。
 　一方、演算制御部５３は、エンジン制御用の電子制御ユニット（図１においては「ＥＣＵ」と表記）２００からグロープラグ１の設定温度及びベースとなるグロープラグ１の印加電圧が指示されるようになっている。この設定温度は、エンジン制御用の電子制御ユニット２００において、エンジンの動作状況に応じて決定されるものである。また、ベースとなるグロープラグ印加電圧は、エンジン制御用の電子制御ユニット２００において、各グロープラグ設定温度及びエンジンの動作状況に応じて、予め把握されているグロープラグ１の電気的特性に基づいて設定された演算式やマップ等を用いて定められるようになっているものである。 The arithmetic control unit 53 stores the correlation between the resistance value of the glow plug 1 and the temperature of the glow plug 1 (glow plug temperature), for example, as a resistance / temperature correlation map, and is obtained as described above. The glow plug temperature with respect to the resistance value of the glow plug 1 is obtained from the resistance-temperature correlation map.
On the other hand, the arithmetic control unit 53 is instructed by the engine control electronic control unit (indicated as “ECU” in FIG. 1) 200 to set the temperature of the glow plug 1 and the voltage applied to the base glow plug 1. It has become. This set temperature is determined in accordance with the operating state of the engine in the electronic control unit 200 for engine control. Further, the glow plug applied voltage as a base is based on the electrical characteristics of the glow plug 1 that are grasped in advance in the electronic control unit 200 for engine control in accordance with each glow plug set temperature and the operating state of the engine. It is determined using a set arithmetic expression, a map, or the like.
 　演算制御部５３においては、エンジン制御用の電子制御ユニット２００から入力されたグロープラグ設定温度と、上述のようにして求められたグロープラグ温度との相関関係から、エンジン制御用の電子制御ユニット２００から入力されたべースとなるグロープラグ印加電圧に対する補正電圧が求められるようになっている。そして、ベースとなるグロープラグ印加電圧が補正電圧分だけ補正され、グロープラグ１の最終的な印加電圧とされる。 In the arithmetic control unit 53, the engine control electronic control unit 200 is calculated from the correlation between the glow plug set temperature input from the engine control electronic control unit 200 and the glow plug temperature obtained as described above. Thus, a correction voltage for the glow plug applied voltage, which is the base input from, is obtained. Then, the glow plug applied voltage as a base is corrected by the correction voltage, and the final applied voltage of the glow plug 1 is obtained.
 　一方、演算制御部５３による通電制御用半導体素子２の駆動制御は、ＰＷＭ制御により行われるようになっており、演算制御部５３においては、グロープラグ１の印加電圧が、上述のようにして補正された所要の電圧となるように、通電制御用半導体素子２に印加されるＰＷＭ信号のデューティが演算処理により算出され、通電制御用半導体素子２へ印加されることで、その導通、非導通が制御されるようになっている。 On the other hand, drive control of the energization control semiconductor element 2 by the arithmetic control unit 53 is performed by PWM control. In the arithmetic control unit 53, the voltage applied to the glow plug 1 is corrected as described above. The duty of the PWM signal applied to the energization control semiconductor element 2 is calculated by an arithmetic process so that the required voltage is obtained, and is applied to the energization control semiconductor element 2 so that conduction or non-conduction is achieved. To be controlled.
 　次に、上述の演算制御部５３によって実行されるグロープラグの故障診断処理の手順について、図２に示されたサブルーチンフローチャートを参照しつつ説明する。
 　まず、図２に示されたサブルーチンフローチャートは、演算制御部５３において従来同様実行されるグロープラグ１の通電駆動制御などと共に演算制御部５３において実行される種々のサブルーチン処理の一つとなっているものである。 Next, the glow plug failure diagnosis process executed by the arithmetic control unit 53 will be described with reference to the subroutine flowchart shown in FIG.
First, the subroutine flowchart shown in FIG. 2 is one of various subroutine processes executed in the arithmetic control unit 53 together with the energization drive control of the glow plug 1 executed in the arithmetic control unit 53 as in the prior art. It is.
 　しかして、演算制御部５３による処理が開始されると、最初に、シャント抵抗器３の両端子間の電圧（シャント電圧）の読み込みが行われる（図２のステップＳ１０２参照）。
 　すなわち、シャント抵抗器３の電圧が、演算増幅器５及びアナログ・ディジタル変換器６を介してディジタル値として演算制御部５３に取り込まれ、適宜な記憶領域に記憶、保持されることとなる。 Thus, when processing by the arithmetic control unit 53 is started, first, a voltage (shunt voltage) between both terminals of the shunt resistor 3 is read (see step S102 in FIG. 2).
That is, the voltage of the shunt resistor 3 is taken into the arithmetic control unit 53 as a digital value via the operational amplifier 5 and the analog / digital converter 6 and stored and held in an appropriate storage area.
 　次いで、ＧＣＵ１００内の温度（筐体内温度）の読み込みが行われる（図２のステップＳ１０４参照）。すなわち、温度検出素子７の出力信号が、演算制御部５３に取り込まれ、筐体内温度として適宜な記憶領域に記憶、保持されることとなる。 次 い で Next, the temperature in the GCU 100 (the temperature in the housing) is read (see step S104 in FIG. 2). That is, the output signal of the temperature detection element 7 is taken into the arithmetic control unit 53 and stored and held in an appropriate storage area as the temperature in the casing.
 　次いで、抵抗補正係数Ｋｒと増幅・変換補正係数Ｋｄの算出が行われる（図２のステップＳ１０６参照）。
 　ここで、抵抗補正係数Ｋｒは、筐体内温度変化を考慮したシャント抵抗器３の実抵抗値を後述するように演算算出する際に用いられる補正係数であり、増幅・変換補正係数Ｋｄは、筐体内温度変化を考慮したアナログ・ディジタル変換器６の正しい出力値を後述するように演算算出する際に用いられる補正係数である。特に、増幅・変換補正係数Ｋｄは、筐体内温度変化による演算増幅器５の出力信号の変動をも包含したものである。 Next, the resistance correction coefficient Kr and the amplification / conversion correction coefficient Kd are calculated (see step S106 in FIG. 2).
Here, the resistance correction coefficient Kr is a correction coefficient used when calculating and calculating the actual resistance value of the shunt resistor 3 considering the temperature change in the casing as will be described later, and the amplification / conversion correction coefficient Kd is the casing. This is a correction coefficient used when calculating and calculating a correct output value of the analog / digital converter 6 in consideration of changes in internal temperature, as will be described later. In particular, the amplification / conversion correction coefficient Kd includes fluctuations in the output signal of the operational amplifier 5 due to temperature changes in the housing.
 　本発明の実施の形態においては、グロープラグ１の実抵抗値を算出するために用いられるシャント抵抗器３の抵抗値や、演算増幅器５、アナログ・ディジタル変換器６の出力値が、その周囲の温度によって変化することに鑑みて、シャント抵抗器３の標準抵抗値、アナログ・ディジタル変換器６の出力値の標準値を、筐体内温度に対応して温度補正し、筐体内温度が考慮された、換言すれば、筐体内温度に対応したシャント抵抗器３の抵抗値及びアナログ・ディジタル変換器６の出力値を得、これをグロープラグ１の実抵抗値の算出に用いることで、従来に比して正確なグロープラグ１の実抵抗値の算出を可能としている。 In the embodiment of the present invention, the resistance value of the shunt resistor 3 used for calculating the actual resistance value of the glow plug 1 and the output values of the operational amplifier 5 and the analog / digital converter 6 are In view of the change depending on the temperature, the standard resistance value of the shunt resistor 3 and the standard value of the output value of the analog / digital converter 6 are corrected according to the temperature in the housing, and the temperature in the housing is taken into consideration. In other words, the resistance value of the shunt resistor 3 and the output value of the analog / digital converter 6 corresponding to the temperature in the housing are obtained and used for calculating the actual resistance value of the glow plug 1. Thus, the actual resistance value of the glow plug 1 can be calculated accurately.
 　筐体内温度を考慮したシャント抵抗器３の抵抗値（シャント補正抵抗値）Ｒｓは、温度変化に対する抵抗素子の一般的な特性に準じて、下記する式１により求めることができる。 抵抗 The resistance value (shunt correction resistance value) Rs of the shunt resistor 3 in consideration of the temperature in the housing can be obtained by the following formula 1 according to the general characteristic of the resistance element with respect to the temperature change.
 　Ｒｓ＝Ｒｃ（１±ＴＣＲ×ΔＴ）・・・式１ Ｒ Rs = Rc (1 ± TCR × ΔT) Equation 1
 　ここで、Ｒｃは、シャント抵抗器３の標準温度（例えば、２４℃）における抵抗値（標準抵抗値）である。また、ＴＣＲは、抵抗補正係数Ｋｒである。さらに、ΔＴは、上述の標準温度とステップＳ１０４で得られた筐体内温度との差である。またさらに、上記式１における符号±は、シャント抵抗器３の温度係数が負の温度係数か、正の温度係数かによって択一的に選択されるものである。 Ｒ Here, Rc is a resistance value (standard resistance value) of the shunt resistor 3 at a standard temperature (for example, 24 ° C.). TCR is a resistance correction coefficient Kr. Further, ΔT is a difference between the above-described standard temperature and the temperature inside the casing obtained in step S104. Furthermore, the sign ± in the above equation 1 is alternatively selected depending on whether the temperature coefficient of the shunt resistor 3 is a negative temperature coefficient or a positive temperature coefficient.
 　抵抗補正係数Ｋｒは、筐体内温度により変化するものであり、本発明の実施の形態においては、抵抗補正係数マップ、又は、抵抗補正係数算出式によって先のステップＳ１０４で取得された筐体内温度に対する抵抗補正係数Ｋｒが求められるようになっている。
 　すなわち、抵抗補正係数マップは、予め試験やシミュレーション結果に基づいて、種々の筐体内温度に対する抵抗補正係数Ｋｒが、筐体内温度を入力パラメータとして読み出し可能に構成されたものであり、演算制御部５３の適宜な記憶領域に予め記憶されたものとなっている。また、抵抗補正係数算出式は、抵抗補正係数マップ同様に、予め試験やシミュレーション結果に基づいて、筐体内温度を引数として、抵抗補正係数Ｋｒが算出できるよう設定された式である。 The resistance correction coefficient Kr changes depending on the temperature in the casing. In the embodiment of the present invention, the resistance correction coefficient Kr corresponds to the temperature in the casing acquired in the previous step S104 by the resistance correction coefficient map or the resistance correction coefficient calculation formula. A resistance correction coefficient Kr is obtained.
That is, the resistance correction coefficient map is configured in advance so that the resistance correction coefficient Kr with respect to various in-chassis temperatures can be read out using the in-chassis temperature as an input parameter based on tests and simulation results. These are stored in advance in appropriate storage areas. Similarly to the resistance correction coefficient map, the resistance correction coefficient calculation expression is an expression set in advance so that the resistance correction coefficient Kr can be calculated based on a test or simulation result using the temperature in the housing as an argument.
 　一方、筐体内温度を考慮したアナログ・ディジタル変換器６の出力信号は、演算増幅器５の筐体内温度変化に伴う増幅率や入出力オフセットの変化をも包含して、下記する式２により求めることができる。
 　なお、本発明の実施の形態においては、演算増幅器５とアナログ・ディジタル変換器６の双方を併せた増幅率は１に設定されている。したがって、下記の式２で得られる電圧値は、演算増幅器５とアナログ・ディジタル変換器６を介したシャント抵抗器３の両端の電圧となる。 On the other hand, the output signal of the analog / digital converter 6 in consideration of the temperature in the housing includes the change in the amplification factor and the input / output offset accompanying the temperature change in the housing of the operational amplifier 5 and is obtained by the following equation 2. Can do.
In the embodiment of the present invention, the amplification factor including both the operational amplifier 5 and the analog / digital converter 6 is set to 1. Therefore, the voltage value obtained by the following equation 2 is the voltage across the shunt resistor 3 via the operational amplifier 5 and the analog / digital converter 6.
 　ＶT＝ｆ（Ｔｕ）×Ｖｓ・・・式２ ＶVT = f (Tu) × Vs ... Equation 2
 　ここで、ＶTは、筐体内温度を考慮したアナログ・ディジタル変換器６のディジタル出力値に相当するアナログ電圧値(シャント補正電圧)である。また、Ｖｓは、ステップＳ１０２で読み込まれたシャント抵抗器３の両端の電圧である。
 　また、ｆ（Ｔｕ）は、先の増幅・変換補正係数Ｋｄを算出する増幅・変換補正係数算出式であり、Ｋｄ＝ｆ（Ｔｕ）と表されるものである。このｆ（Ｔｕ）は、試験結果やシミュレーション結果等に基づいて設定されたもので、Ｔｕは、先のステップＳ１０４で得られた筐体内温度である。
 　すなわち、ｆ（Ｔｕ）は、筐体内温度の変化による演算増幅器５の特性変動をも含んだアナログ・ディジタル変換器６のディジタル出力値の変動が生じても、シャント抵抗器３の両端の電圧について、本来の正しい値が得られるよう筐体内温度を入力パラメータとして増幅・変換補正係数Ｋｄが定められるよう試験結果やシミュレーション結果に基づいて設定されたものである。 Here, VT is an analog voltage value (shunt correction voltage) corresponding to the digital output value of the analog / digital converter 6 in consideration of the temperature in the housing. Vs is the voltage across the shunt resistor 3 read in step S102.
F (Tu) is an amplification / conversion correction coefficient calculation formula for calculating the previous amplification / conversion correction coefficient Kd, and is expressed as Kd = f (Tu). This f (Tu) is set based on the test result, the simulation result, etc., and Tu is the temperature inside the casing obtained in the previous step S104.
That is, f (Tu) is the voltage across the shunt resistor 3 even if the digital output value of the analog-to-digital converter 6 including the characteristic fluctuation of the operational amplifier 5 due to the change in the temperature inside the casing occurs. The amplification / conversion correction coefficient Kd is set based on the test result and the simulation result so that the temperature inside the casing is an input parameter so that the original correct value can be obtained.
 　上述のようにして抵抗補正係数Ｋｒ、及び、増幅・変換補正係数Ｋｄが求められた後は、これら抵抗補正係数Ｋｒ、及び、増幅・変換補正係数Ｋｄを用いてシャント補正抵抗値、及び、シャント補正電圧の算出が行われる（図２のステップＳ１０８参照）。
 　すなわち、まず、シャント補正抵抗値Ｒｓは、先の式１により求められる。
 　次いで、シャント補正電圧ＶTは、先の式２によって求められる。 After the resistance correction coefficient Kr and the amplification / conversion correction coefficient Kd are obtained as described above, the shunt correction resistance value and the shunt are obtained using the resistance correction coefficient Kr and the amplification / conversion correction coefficient Kd. The correction voltage is calculated (see step S108 in FIG. 2).
That is, first, the shunt correction resistance value Rs is obtained by the above equation 1.
Next, the shunt correction voltage VT is obtained by the above equation 2.
 　次に、グロープラグ１に流れる電流が算出される（図２のステップＳ１１０参照）。
 　すなわち、グロープラグ１を流れる電流（グロー電流）Ｉｇは、シャント抵抗器３を流れる電流でもあるので、下記する式３により求められる。 Next, the current flowing through the glow plug 1 is calculated (see step S110 in FIG. 2).
That is, the current (glow current) Ig that flows through the glow plug 1 is also a current that flows through the shunt resistor 3, and thus can be obtained by the following equation (3).
 　Ｉｇ＝ＶT／Ｒｓ・・・式３ Ig = VT / Rs ... Equation 3
 　ここで、ＶTは、ステップＳ１０８で得られたシャント補正電圧、Ｒｓは、ステップＳ１０８で得られたシャント補正抵抗値である。
 　次いで、ステップＳ１１２において、上述のグロー電流Ｉｇを基にグロープラグの故障判定が行われることとなる。
 　すなわち、グロー電流Ｉｇが所定の閾値Ｋを超えているか否かが判定され、所定の閾値を超えていないと判定された場合（ＮＯの場合）には、正常であるとされ（図２のステップＳ１１４参照）、一連の処理が終了されて、図示されないメインルーチンへ戻り、グロープラグ１の通電制御が継続されることとなる。 Here, VT is the shunt correction voltage obtained in step S108, and Rs is the shunt correction resistance value obtained in step S108.
Next, in step S112, failure determination of the glow plug is performed based on the above-described glow current Ig.
That is, it is determined whether or not the glow current Ig exceeds a predetermined threshold value K. When it is determined that the glow current Ig does not exceed the predetermined threshold value (in the case of NO), it is determined to be normal (step of FIG. 2). S114), a series of processing is completed, the process returns to the main routine (not shown), and energization control of the glow plug 1 is continued.
 　一方、ステップＳ１１２においてグロー電流Ｉｇが所定の閾値Ｋを超えていると判定された場合（ＹＥＳの場合）には、グロープラグ１は故障と判定され（図２のステップＳ１１６参照）、図示されないメインルーチンへ戻り、従来同様、警報表示等の警報処理や、必要に応じてグロープラグ１への通電制御の停止等の処理が実行されることとなる。 On the other hand, when it is determined in step S112 that the glow current Ig exceeds the predetermined threshold K (in the case of YES), it is determined that the glow plug 1 is in failure (see step S116 in FIG. 2), and the main not shown. Returning to the routine, as in the prior art, an alarm process such as an alarm display, or a process of stopping energization control to the glow plug 1 is executed as necessary.
 　なお、ステップＳ１１２における閾値Ｋは、従来同様、グロープラグ駆動制御装置１００が用いられる温度範囲、例えば、－４０℃～１０５℃を考慮して、試験結果やシミュレーション結果を基に、最も好適な値として設定されたものである。
 　本発明の実施の形態においては、先に述べたようにグロー電流Ｉｇは、グロープラグ駆動制御装置１００の筐体温度に対応して補正されたシャント抵抗器３の両端の電圧ＶT及び抵抗値Ｒｓに基づいて求められたものであるため、従来と異なり、閾値Ｋ自体が、グロー電流Ｉｇの適否を判断する基準として適切で無くなるようなことが確実に回避され、ステップＳ１１２における判定は、従来と異なり、精度が高く、信頼性の高いものとなる。 The threshold value K in step S112 is the most suitable value based on test results and simulation results in consideration of the temperature range in which the glow plug drive control device 100 is used, for example, −40 ° C. to 105 ° C. Is set as.
In the embodiment of the present invention, as described above, the glow current Ig is corrected by the voltage VT and the resistance value Rs across the shunt resistor 3 corrected in accordance with the casing temperature of the glow plug drive control device 100. Therefore, unlike the conventional case, it is reliably avoided that the threshold value K itself is not appropriate as a criterion for determining the suitability of the glow current Ig. The determination in step S112 is the same as the conventional case. In contrast, it is highly accurate and reliable.
 　信頼性の高いグロープラグの故障診断が所望されるグロープラグを備えたエンジンを用いる車両などに適する。 適 Suitable for vehicles using an engine equipped with a glow plug where a reliable diagnosis of the glow plug is desired.

Claims (4)

  1.  　グロープラグが、バッテリとグランドとの間に、通電制御用半導体素子及びシャント抵抗器と共に直列接続されて設けられる一方、前記グロープラグの通電制御を可能とするために前記通電制御用半導体素子の動作制御可能に構成されてなる演算制御部と、前記シャント抵抗器の電圧を前記演算制御部へ供給可能に構成されてなる計測回路とが、前記シャント抵抗器と共に同一の筐体内に設けられ、前記シャント抵抗器の両端の電圧が、前記演算制御部による前記グロープラグの電圧、電流の認識に供されるよう構成されてなるグロープラグ故障診断装置におけるグロープラグの故障診断方法であって、
     　前記計測回路を介して得られた前記シャント抵抗器の電圧を、前記筐体内の温度に基づいて補正してシャント補正電圧とすると共に、前記シャント抵抗器の所定の標準値を前記筐体内の温度に基づいて補正してシャント補正抵抗値とし、
     　前記シャント補正電圧を前記シャント補正抵抗値で除し、その除算結果を前記グロープラグの電流であるグロー電流とし、
     　前記グロー電流が所定の閾値を越える場合に、前記グロープラグの故障と判断することを特徴とするグロープラグの故障診断方法。     A glow plug is provided in series with a current control semiconductor element and a shunt resistor between the battery and the ground, and the operation of the current control semiconductor element to enable current control of the glow plug. An arithmetic control unit configured to be controllable and a measurement circuit configured to be able to supply the voltage of the shunt resistor to the arithmetic control unit are provided in the same casing together with the shunt resistor, A glow plug fault diagnostic method in a glow plug fault diagnostic apparatus configured to be used for recognizing the voltage and current of the glow plug by the arithmetic control unit, the voltage across the shunt resistor,
    The voltage of the shunt resistor obtained through the measurement circuit is corrected based on the temperature in the casing to obtain a shunt correction voltage, and a predetermined standard value of the shunt resistor is set to the temperature in the casing. Is corrected to the shunt correction resistance value based on
    The shunt correction voltage is divided by the shunt correction resistance value, and the division result is a glow current that is the current of the glow plug,
    A glow plug failure diagnosis method, wherein the glow plug failure is determined when the glow current exceeds a predetermined threshold.
  2.  　前記シャント補正電圧は、シャント抵抗器の両端の電圧に所定の増幅・変換補正係数を乗じて求められ、前記所定の増幅・変換補正係数は、前記筐体内の温度を入力パラメータとして予め定められた関数により求められる一方、
     　前記シャント補正抵抗値は、前記筐体内の温度と前記標準温度との温度差と前記シャント抵抗器の温度係数との乗算値を、前記シャント抵抗器の標準温度における抵抗値に乗じ、その乗算結果を、前記シャント抵抗器の標準温度における抵抗値に、前記温度係数の正負に応じて加減算して求められたものであることを特徴とする請求項１記載のグロープラグの故障診断方法。     The shunt correction voltage is obtained by multiplying the voltage at both ends of the shunt resistor by a predetermined amplification / conversion correction coefficient, and the predetermined amplification / conversion correction coefficient is determined in advance using the temperature in the casing as an input parameter. While determined by the function
    The shunt correction resistance value is obtained by multiplying a resistance value at a standard temperature of the shunt resistor by a product of a temperature difference between the temperature in the housing and the standard temperature and a temperature coefficient of the shunt resistor. 2. The glow plug failure diagnosis method according to claim 1, wherein a resistance value at a standard temperature of the shunt resistor is added to or subtracted according to the sign of the temperature coefficient.
  3.  　グロープラグが、バッテリとグランドとの間に、通電制御用半導体素子及びシャント抵抗器と共に直列接続されて設けられる一方、前記グロープラグの通電制御を可能とするために前記通電制御用半導体素子の動作制御可能に構成されてなる演算制御部と、前記シャント抵抗器の電圧を前記演算制御部へ供給可能に構成されてなる計測回路とが、前記シャント抵抗器と共に同一の筐体内に設けられ、前記シャント抵抗器の両端の電圧が、前記演算制御部による前記グロープラグの電圧、電流の認識に供されるよう構成されてなるグロープラグ故障診断装置であって、
     　前記演算制御部は、
     　前記計測回路を介して得られた前記シャント抵抗器の電圧を、前記筐体内の温度に基づいて補正してシャント補正電圧として算出すると共に、前記シャント抵抗器の所定の標準値を前記筐体内の温度に基づいて補正してシャント補正抵抗値として算出し、
     　前記シャント補正電圧を前記シャント補正抵抗値で除し、その除算結果を前記グロープラグの電流であるグロー電流とし、
     　前記グロー電流が所定の閾値を越える場合に、前記グロープラグの故障と判断するよう構成されてなることを特徴とするグロープラグ故障診断装置。     A glow plug is provided in series with a current control semiconductor element and a shunt resistor between the battery and the ground, and the operation of the current control semiconductor element to enable current control of the glow plug. An arithmetic control unit configured to be controllable and a measurement circuit configured to be able to supply the voltage of the shunt resistor to the arithmetic control unit are provided in the same casing together with the shunt resistor, A glow plug fault diagnosis device configured such that the voltage across the shunt resistor is used for recognition of the voltage and current of the glow plug by the arithmetic control unit,
    The arithmetic control unit is
    The voltage of the shunt resistor obtained through the measurement circuit is corrected based on the temperature in the casing and calculated as a shunt correction voltage, and a predetermined standard value of the shunt resistor is calculated in the casing. Correct based on temperature and calculate as shunt correction resistance value,
    The shunt correction voltage is divided by the shunt correction resistance value, and the division result is a glow current that is the current of the glow plug,
    A glow plug failure diagnosis apparatus configured to determine that a glow plug has failed when the glow current exceeds a predetermined threshold.
  4.  　前記演算制御部は、前記筐体内の温度を入力パラメータとして予め定められた関数により増幅・変換補正係数を算出し、前記シャント抵抗器の両端の電圧に前記増幅・変換補正係数を乗じて前記シャント補正電圧を算出する一方、
     　前記筐体内の温度と前記標準温度との温度差と前記シャント抵抗器の温度係数との乗算値を算出し、当該乗算値を前記シャント抵抗器の標準温度における抵抗値に乗じ、その乗算結果を、前記シャント抵抗器の標準温度における抵抗値に、前記温度係数の正負に応じて加減算してシャント補正抵抗値を算出するよう構成されてなることを特徴とする請求項３記載のグロープラグ故障診断装置。     The arithmetic control unit calculates an amplification / conversion correction coefficient by a predetermined function using the temperature in the casing as an input parameter, and multiplies the voltage at both ends of the shunt resistor by the amplification / conversion correction coefficient. While calculating the correction voltage,
    Calculate a multiplication value of the temperature difference between the temperature in the housing and the standard temperature and the temperature coefficient of the shunt resistor, multiply the multiplication value by the resistance value at the standard temperature of the shunt resistor, and multiply the multiplication result by 4. The glow plug fault diagnosis according to claim 3, wherein a shunt correction resistance value is calculated by adding to or subtracting from the resistance value at a standard temperature of the shunt resistor according to the sign of the temperature coefficient. apparatus.
PCT/JP2014/080608 2013-12-20 2014-11-19 Glow plug failure diagnostic method and glow plug failure diagnostic apparatus WO2015093219A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2015553439A JP6188170B2 (en) 2013-12-20 2014-11-19 Glow plug fault diagnosis method and glow plug fault diagnosis device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2013-263249 2013-12-20
JP2013263249 2013-12-20

Publications (1)

Publication Number Publication Date
WO2015093219A1 true WO2015093219A1 (en) 2015-06-25

Family

ID=53402574

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/080608 WO2015093219A1 (en) 2013-12-20 2014-11-19 Glow plug failure diagnostic method and glow plug failure diagnostic apparatus

Country Status (2)

Country Link
JP (1) JP6188170B2 (en)
WO (1) WO2015093219A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105842577A (en) * 2016-03-23 2016-08-10 华中科技大学 Power converter open-circuit fault diagnosis method in AC variable-frequency speed regulation system
CN111997757A (en) * 2020-07-31 2020-11-27 东风商用车有限公司 Failure diagnosis method for air inlet preheater of engine

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009099638A (en) * 2007-10-15 2009-05-07 Denso Corp Semiconductor device
JP2010180812A (en) * 2009-02-06 2010-08-19 Ngk Spark Plug Co Ltd Glow plug failure diagnostic system
JP2011125130A (en) * 2009-12-10 2011-06-23 Panasonic Corp Inverter drive
JP2012233661A (en) * 2011-05-09 2012-11-29 Denso Corp Glow plug with built-in controller
WO2013000621A1 (en) * 2011-06-29 2013-01-03 Robert Bosch Gmbh Method and system for calibrating a shunt resistor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009099638A (en) * 2007-10-15 2009-05-07 Denso Corp Semiconductor device
JP2010180812A (en) * 2009-02-06 2010-08-19 Ngk Spark Plug Co Ltd Glow plug failure diagnostic system
JP2011125130A (en) * 2009-12-10 2011-06-23 Panasonic Corp Inverter drive
JP2012233661A (en) * 2011-05-09 2012-11-29 Denso Corp Glow plug with built-in controller
WO2013000621A1 (en) * 2011-06-29 2013-01-03 Robert Bosch Gmbh Method and system for calibrating a shunt resistor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105842577A (en) * 2016-03-23 2016-08-10 华中科技大学 Power converter open-circuit fault diagnosis method in AC variable-frequency speed regulation system
CN111997757A (en) * 2020-07-31 2020-11-27 东风商用车有限公司 Failure diagnosis method for air inlet preheater of engine

Also Published As

Publication number Publication date
JP6188170B2 (en) 2017-08-30
JPWO2015093219A1 (en) 2017-03-16

Similar Documents

Publication Publication Date Title
JP5802757B2 (en) Glow plug diagnosis method and glow plug drive control device
US9347903B2 (en) Method for detecting the type of lambda probes
JP4383597B2 (en) Battery detection device and temperature detection method
US10359321B2 (en) On-chip circuit and method for accurately measuring die temperature of an integrated circuit
US20190257860A1 (en) Voltage detection and determination circuit and power battery system having same
JP6188170B2 (en) Glow plug fault diagnosis method and glow plug fault diagnosis device
US8265894B2 (en) Method for estimating the temperature in an internal combustion engine
US7359172B2 (en) Junction temperature sensing for MOSFET
JP5995993B2 (en) Glow plug diagnostic method and vehicle glow plug drive control device
US11143560B2 (en) Electronic circuit for driving a thermocouple element, temperature sensing device, and method for observing a leakage resistance of the thermocouple element
FR3094499A1 (en) Method and device for estimating the aging of an electronic component
RU2013148725A (en) METHOD FOR CORRECTION OF VOLTAGE MEASUREMENT ON SENSOR CONTACTS
US11656284B2 (en) Method for operating a battery sensor, and battery sensor
CN111044913B (en) Method for operating a battery sensor and battery sensor
US10697930B2 (en) Method for diagnosing a lambda sensor during ongoing operation
KR20180028127A (en) Temperature measure apparatus of thermocouple and data measure system for performance verification test of marine large engine using the same
JP2014109238A (en) Voltage/electric current calculating method for glow plug, and glow plug drive control unit
US10352224B2 (en) Method of operating a drive device and corresponding drive device
JP6080691B2 (en) Temperature measuring device, temperature measuring method, and semiconductor module
US9341156B2 (en) Glow plug, new glow plug determination method, and glow plug driving control device
JP6344016B2 (en) Temperature measuring device
CN112858934A (en) Method for testing a battery sensor, and battery sensor
JPH05288113A (en) Sucked air flow detection apparatus for internal combustion engine
JP2003241994A (en) Inspection and setting method for input circuit of electronic control unit, and electronic control unit
FR3042861A1 (en) TEMPERATURE SENSOR FOR A MOTOR VEHICLE COMPRISING A THERMOCOUPLE

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14872323

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2015553439

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14872323

Country of ref document: EP

Kind code of ref document: A1