WO2021065204A1 - Response characteristic diagnosing method for pressure sensor used in engine control - Google Patents

Response characteristic diagnosing method for pressure sensor used in engine control Download PDF

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Publication number
WO2021065204A1
WO2021065204A1 PCT/JP2020/030272 JP2020030272W WO2021065204A1 WO 2021065204 A1 WO2021065204 A1 WO 2021065204A1 JP 2020030272 W JP2020030272 W JP 2020030272W WO 2021065204 A1 WO2021065204 A1 WO 2021065204A1
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pressure sensor
responsiveness
engine
engine control
pressure
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PCT/JP2020/030272
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French (fr)
Japanese (ja)
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武相 瀧川
良太 足立
友宜 須藤
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株式会社ニッキ
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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
    • F02D45/00—Electrical control not provided for in groups F02D41/00 - F02D43/00
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

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  • the present invention relates to a method for diagnosing the responsiveness of a pressure sensor used for engine control in an intake system and an exhaust system of a spark-ignition engine.
  • an electronic control system has been used instead of mechanically opening and closing the throttle by operating the accelerator by the driver.
  • Electronically controlled throttle control devices that electronically open and close the throttle are widely used, and are described in, for example, JP-A-5-240073 and JP-A-2008-38872.
  • ECU electronice control unit device
  • Pressure sensors are used in the intake and exhaust systems to measure the pressure of the mixed gas and the pressure of the exhaust gas, and in particular, the pressure sensor of the exhaust system is contained in the exhaust gas, soot and unburned. There is a problem that the pressure cannot be measured accurately because the pressure measuring unit is blocked by a substance such as fuel or engine oil, and the engine cannot be controlled in the event of a failure.
  • the means for diagnosing the responsiveness of the pressure sensor used for engine control presented in these publications is an intake arranged in the intake manifold 2 of the engine, for example, as shown in FIG. 21 showing the intake manifold pressure sensor as a pressure sensor.
  • a manifold pressure sensor [Pmap] is connected to the ECU 3, input to the microcomputer 4, and engine control is performed based on the information of the intake manifold pressure sensor [Pmap].
  • the intake manifold pressure is performed inside the microcomputer 4.
  • the pressure sensor response diagnosis circuit 8 determines whether or not the responsiveness of the sensor [Pmap] ensures appropriate performance.
  • the throttle valve 6 is closed or opened, and then the other and then again.
  • the closing operation is performed a plurality of times at predetermined periods, and the difference in pressure detected by the intake manifold intake pressure sensor [Pmap] during one opening / closing operation is calculated as the pressure change amount, and the plurality of the above-mentioned By comparing the amount of change in pressure for each opening / closing operation, the responsiveness of the intake manifold pressure sensor [Pmap] is diagnosed.
  • the intake manifold pressure sensor [Pmap] in the diagnostic means shown in FIG. 21, it is arranged in the air upstream portion of the intake manifold pressure sensor [Pmap] as shown in FIG.
  • the time when the intake manifold pressure sensor [Pmap] starts up is measured from the time when the throttle valve 6 starts to open by detecting the opening sensor information signal (TH) of the throttle valve 6, and the time difference between the two is defined as ⁇ T1 as the response time.
  • TH opening sensor information signal
  • the trigger for starting the diagnosis is a transient condition of acceleration or deceleration, and various acceleration conditions are used in the implementation on a general public road in a vehicle. Therefore, there is a problem that uniform transient conditions may not be obtained, the diagnostic results vary widely, and it is difficult to judge the correct responsiveness of the pressure sensor.
  • the present invention has been made to solve the above problems, and various pressure sensors for preventing the pressure sensor used for engine control in the intake system or the exhaust system of the engine from being unable to measure accurately in advance.
  • An object of the present invention is to provide a responsiveness diagnostic method.
  • the present invention made to solve the above problems is a method for diagnosing responsiveness deterioration of a pressure sensor provided in an intake system or an exhaust system of an engine used for spark ignition type engine control, and is used when the engine is operating.
  • the pressure sensor signal information obtained by measuring the pressure sensor signal information, which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the engine by the intake or exhaust accompanying the reciprocating movement of the piston, and converting it into an index value, is the normal pressure sensor signal information. It is characterized in that deterioration of responsiveness caused in the pressure sensor used for controlling the engine is diagnosed by comparing with the normal index value converted from the above.
  • the pressure sensor signal information which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the measured engine is processed by the analog filter low-pass filter circuit arranged inside the engine control device and converted into an index value. By doing so, the pressure pulsation amplitude can be appropriately processed.
  • the pressure sensor signal information which is the measured pressure pulsation amplitude generated in the intake system or the exhaust system of the engine, is processed by a digital low-pass filter circuit arranged inside the engine control device and converted into an index value to obtain the pressure pulsation.
  • the amplitude can be processed more appropriately.
  • the processing by the digital low-pass filter circuit is performed by the pressure sensor from the pressure sensor signal information having high frequency vibration, the band passing filter and the absolute value processing, and the weighted averaging processing.
  • the present invention by updating the maximum value of the obtained index value during engine operation and evaluating this maximum value, not only specific operating conditions but also various operating conditions can be set as one index.
  • the number of measurements can be reduced by determining the deterioration of responsiveness.
  • the pressure sensor provided in the intake system or the exhaust system of the engine is a sensor in which pressure pulsation appears in steady operation, the determination of responsiveness deterioration is made from the index value without experiencing acceleration conditions or the like. It is possible to do.
  • the pressure sensor signal information which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the measured engine is used as a low frequency band which is arranged inside the engine control device and removes a high frequency band unnecessary for engine control.
  • the present invention it is possible to diagnose an abnormal state of responsiveness of a pressure sensor in advance without complicating the structure of the pressure sensor, and in particular, specific acceleration / deceleration conditions are not always required as diagnostic conditions. Not only that, since there is a possibility that the responsiveness of the pressure sensor can be diagnosed even in the steady operation state, it is possible to diagnose the deterioration of the responsiveness of the pressure sensor with high accuracy and high diagnosis execution rate under the vehicle usage conditions.
  • FIG. 6 is a schematic view of a preferred embodiment when the present invention is carried out for an intake manifold pressure sensor [Pmap].
  • Intake pressure which is pressure sensor signal information, is pressure pulsation amplitude generated by intake air caused by the reciprocating movement of the piston of the intake manifold pressure sensor [Pmap] when the engine in the embodiment shown in FIG. 2 is in steady operation (idling operation).
  • Explanatory drawing which shows the time series data of [kPa].
  • the explanatory view which shows the index value of the pressure pulsation in the embodiment shown in FIG.
  • the measurement figure which shows an example of the design of the bandpass filter which extracts the amplitude from the pressure sensor signal used in this invention.
  • the explanatory view of the failure diagnosis method concerning the responsiveness of the pressure sensor in this invention The pressure amplitude and time series measurement figure of the responsiveness diagnosis in this embodiment of the fuel injection pressure sensor [Pinj] in a normal state.
  • the pressure amplitude and time series measurement diagram of the responsiveness diagnosis in this embodiment of the fuel injection pressure sensor [Pinj] in a state where the responsiveness is deteriorated corresponding to the time constant (Tc) 1.0 s.
  • FIG. 6 is a measurement diagram showing an execution result of a responsiveness diagnosis in a normal state according to an embodiment of the present invention in a fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG. 7.
  • Execution result of responsiveness diagnosis when responsiveness deterioration corresponding to time constant (Tc) 0.1 s in the embodiment of the present invention is given to the fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG.
  • FIG. 3 is a measurement diagram of pressure amplitude and time series of responsiveness diagnosis in the present embodiment of the intake manifold pressure sensor [Pmap] in a normal state.
  • FIG. 3 is a measurement diagram showing an execution result of a responsiveness diagnosis in a normal state according to an embodiment of the present invention in an intake manifold pressure sensor [Pmap] showing the characteristics shown in FIG.
  • Execution result of responsiveness diagnosis when responsiveness deterioration corresponding to time constant (Tc) 0.1s in the embodiment of the present invention is given to the intake manifold pressure sensor [Pmap] showing the characteristics shown in FIG.
  • the measurement diagram which shows.
  • Responsiveness diagnosis in the case of giving a responsiveness deterioration corresponding to a time constant (Tc) 0.1s in the embodiment of the present invention in the EGR valve upstream gas pressure sensor [Pegr] showing the characteristics shown in FIG. A measurement diagram showing the execution result.
  • Responsiveness diagnosis in the case of giving a responsiveness deterioration corresponding to a time constant (Tc) 1.0 s in the embodiment of the present invention in the EGR valve upstream gas pressure sensor [Pegr] showing the characteristics shown in FIG.
  • the present invention relates to an engine provided with an exhaust gas recirculation (Exhaust Gas Recirculation, hereinafter referred to as "EGR") device that uses exhaust gas as a gas to be mixed with fuel, for example, for the purpose of improving fuel efficiency, as shown in FIG.
  • EGR exhaust Gas Recirculation
  • the exhaust system pressure sensor such as the turbo outlet exhaust pressure sensor [Ptcout] and the EGR valve upstream pressure sensor [Pegr]
  • the intake system pressure sensor such as the intake manifold pressure sensor [Pmap] and the turbo upstream air.
  • pressure sensors used in various places used for engine control such as a pressure sensor [Pair], an upstream throttle pressure sensor [Pth], and a fuel injection pressure sensor [Pinj].
  • FIG. 2 shows a preferred embodiment of the intake manifold pressure sensor [Pmap] installed in the intake manifold 2 of the engine 1 among the pressure sensors when the present invention is implemented, and shows the intake manifold pressure.
  • the information of the sensor [Pmap] is input to the ECU 3 via the wire harness.
  • the ECU 3 is provided with an analog filter circuit 9 composed of electronic components for removing noise components unnecessary for engine control and a digital filter processing circuit 11 composed of software.
  • the filter unit used in this technology is equipped with a filter device consisting of an analog filter circuit 10 and a digital filter circuit 13 that can observe a high frequency band in order to detect engine pulsation components.
  • a failure diagnosis of responsiveness deterioration is performed based on this information, but by performing the failure diagnosis by the engine control processing circuit 5 based on the information obtained by providing the digital filter circuits 12 in parallel and performing the filter processing different from the diagnostic response processing. Even if the sensor input circuit is changed, engine control that is the same as before is possible.
  • FIG. 3 shows a time series of intake pressure [kPa], which is pressure sensor signal information consisting of pressure pulsation amplitude generated by intake air accompanying the reciprocating movement of the piston of the intake manifold pressure sensor [Pmap] when the engine is in steady operation (idling operation). It shows the data.
  • kPa pressure sensor signal information consisting of pressure pulsation amplitude generated by intake air accompanying the reciprocating movement of the piston of the intake manifold pressure sensor [Pmap] when the engine is in steady operation (idling operation). It shows the data.
  • each pressure sensor signal to be diagnosed in the present embodiment goes through a process of becoming a pressure sensor amplitude value (RES_AMP) through a band passage filter and absolute value processing, and the pressure sensor amplitude Since the value (RES_AMP) is superimposed as a high frequency component that includes not only the pressure pulsation that occurs constantly but also the transient change during acceleration / deceleration, appropriate smoothing processing is performed by weighted averaging processing. It is relatively easy to extract the response as a numerical value and update the maximum value by the maximum value update process in a specific driving cycle (for example, the entire section during operation from the engine start to the next engine start).
  • the pressure sensor responsiveness deterioration index (RES_IDX) can be obtained by quantifying the maximum response of the pressure sensor as an index value by various methods.
  • a bandpass filter that extracts the amplitude from each pressure sensor signal
  • Fig. 5 shows an example. It is characterized by improving the detection accuracy by removing DC components and electrical noise components that are unnecessary for responsiveness diagnosis by cutting 1 Hz or less in the low range and 10 Hz or more in the high range.
  • These bandpass filters can be implemented in a microcomputer with a relatively small amount of resources by using general finite impulse response (FIR) filter or infinite impulse response filter (IIR) filter technology. Needless to say.
  • the higher the responsiveness of the pressure sensor the higher the index value obtained here.
  • the index value changes depending on the pressure pulsation generated in the pressure sensor, so that the index value changes depending on the operating conditions. Will be affected.
  • a determination process for calculating flag information indicating experience is performed, and when this flag information is "true", the pressure sensor responsiveness deterioration index (RES_IDX) described above is obtained. It is possible to judge the correct responsiveness by making a judgment based on the responsiveness deterioration index (RES_IDX) of the pressure sensor.
  • the pressure sensor responsiveness deterioration index (RES_IDX) shows a high value, and if the responsiveness deteriorates, the pressure sensor responsiveness deterioration index (RES_IDX) shows a low value. Shown.
  • the pressure sensor responsiveness deterioration index (RES_IDX) is lower than the responsiveness failure diagnosis threshold and the logical product is determined as "true” (True) of the operating condition experience flag. It is logical that the value of the pressure sensor responsiveness deterioration index (RES_IDX) is higher than the responsiveness failure diagnosis threshold and the operating condition experience flag is "true” (True).
  • the sensor responsiveness is determined to be normal, and a failure diagnosis regarding the responsiveness of the pressure sensor is performed.
  • FIG. 7 shows the data when the fuel injection pressure sensor [Pinj] is operated in the World-wide Hamonized Transient Cycle test mode (hereinafter referred to as "WHTC test mode") on the engine table in a normal state.
  • the upper graph shows the data about the time series [s (seconds)] of the pressure pulsation [kPa] from the fuel injection pressure sensor [Pinj], which is determined in the WHTC test mode starting from the engine stopped state. Each steady and transient operation is carried out.
  • the graph shown in the lower part of FIG. 7 shows the fuel injection pressure sensor signal, which is a vibration component observed by the operation of the fuel injection valve in the idle operation state of interest in the upper graph, subjected to a short-time fast Fourier transform.
  • the horizontal axis is the time axis
  • the vertical axis is the frequency band.
  • the middle graph in FIG. 7 shows the amplitude of the frequency band in the lower graph by shading, and the lighter the color, the larger the vibration.
  • FIG. 8 and 9 show the results of intentionally deteriorating the responsiveness of the fuel injection pressure sensor [Pinj] in the fuel injection pressure sensor signal of the fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG. 7.
  • the high frequency component decreases when the responsiveness of the fuel injection pressure sensor deteriorates as a whole even under operating conditions other than the idle condition.
  • FIG. 10 to 12 show the execution result of the responsiveness diagnosis according to the embodiment of the present invention in the fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG. 7, and FIG. 10 shows the diagnosis of the normal state.
  • FIG. 11 shows the execution result
  • the diagnosis execution result when is given is shown respectively.
  • the elapsed time tends to be saturated to almost a constant value in about 600 s. This can be determined by utilizing the flag information of the driving area experience determination process in the above-mentioned diagnostic program because it is known that various operating conditions have been experienced.
  • 13 to 16 show the operation of the embodiment of the present invention when the intake manifold pressure sensor [Pmap] is adopted as the pressure sensor.
  • FIG. 13 shows the data according to the embodiment of the present invention when the intake manifold pressure sensor [Pmap] is operated in the WHTC test mode on the engine table in a normal state, and the upper graph shows the intake manifold pressure. It shows the data for the time series [s (seconds)] of the pressure pulsation [kPa] from the sensor [Pmap], starting from the engine stopped state and each steady and transient defined in the WHTC test mode. The operation is being carried out.
  • harmonics of about 300 Hz can be observed due to pressure pulsation, but the amplitude is small and deterioration cannot be determined. Further, in the steady operation region of high rotation and high load in the latter half of the mode, the harmonic component due to the pressure amplitude can be observed in the same manner, but the amplitude is small and the deterioration cannot be judged only by this information.
  • FIGS. 14 to 16 show the observation results of the embodiment of the present invention when the intake manifold pressure sensor [Pint] is used as the pressure sensor in the present invention.
  • FIG. 14 shows the diagnosis execution result in the normal state
  • the results of executing the diagnosis when the responsiveness deterioration corresponding to 0 s is given are shown respectively.
  • FIG. 14 which is the execution result of the response performance diagnosis with the normal intake manifold pressure sensor [Pmap]
  • the amplitude value (RES_AMP) of the pressure sensor shows near 0 in the idle state, and the high rotation and high load in the latter half. Since it is also small in the steady operation region of the above, it can be understood that the responsiveness deterioration cannot be determined using the information of the pressure sensor responsiveness deterioration index (RES_IDX). Focusing on the information of the pressure sensor responsiveness deterioration index (RES_IDX) calculated by the diagnostic program, the pressure sensor responsiveness deterioration index (RES_IDX) of the intake manifold pressure sensor [Pmap] is up to around 80 at the end of the test mode. You can see that it is rising.
  • the amplitude value (RES_AMP) of the pressure sensor in the idle state and the high-speed / high-load steady-state operation region in the latter half is not different from that of the normal intake manifold pressure sensor, and the amplitude value of the pressure sensor (RES_AMP) responds even when the pressure sensor is operated. Sexual deterioration cannot be determined.
  • the determination means is the same as that of the embodiment of the fuel injection pressure sensor [Pinj] shown in FIGS. 10 to 13, and the description thereof will be omitted.
  • FIGS. 17 to 20 will explain the operation in the embodiment of the invention when the EGR valve upstream gas pressure sensor [Pegr] is adopted as the pressure sensor.
  • FIG. 17 shows the data when the WHTC test mode on the engine table is operated in the normal state of the EGR valve upstream gas pressure sensor [Pegr], and the upper graph is from the EGR valve upstream gas pressure sensor [Pegr].
  • the time series data of the pressure pulsation [kPa] is shown, and the lower part of the graph shows the frequency and amplitude component of the EGR valve upstream gas pressure sensor [Pegr] on the same time axis as the upper part.
  • the EGR valve upstream gas pressure sensor [Pegr] can observe harmonics of about 40 Hz in idle operation, but the amplitude is small and relatively large in the high rotation and high load steady operation range in the latter half of the mode. The pressure amplitude can be observed.
  • FIGS. 18 to 20 show the execution results of the responsiveness diagnosis when the present invention is carried out for the EGR valve upstream gas pressure sensor [Pegr] having the pressure vibration shown in FIG.
  • FIG. 18 shows the diagnosis execution result in the normal state
  • the diagnosis execution results when the responsiveness deterioration corresponding to 1.0 s is given are shown respectively.
  • the amplitude value (RES_AMP) of the pressure sensor hardly changes, and the amplitude of the pressure sensor. Judgment by value (RES_AMP) is difficult.
  • the determination means is the same as that of the embodiment of the fuel injection pressure sensor [Pinj] shown in FIGS. 10 to 12, and the description thereof will be omitted.
  • the pulsating component superimposed on the pressure sensor is measured, the pressure amplitude is converted into an index value by a simple filter signal processing, and the pressure is determined in combination with the experience flag of the operating condition.
  • Specific acceleration / deceleration conditions are not always required for diagnostic conditions, and in addition, the responsiveness of the pressure sensor may be diagnosed even in steady operation conditions, so accuracy is high and under vehicle usage conditions. It is possible to provide a deterioration diagnosis of the response performance of a pressure sensor having a high diagnosis execution rate.
  • 1 engine 1 engine, 2 intake manifold, 3 ECU, 4 microcomputer, 5 engine control processing circuit, 6 throttle valve, 7 throttle valve opening sensor, 8 pressure sensor failure diagnosis circuit, 9, 10 analog filter circuit, 11, 12, 13 Digital filter circuit, Pinj fuel injection pressure sensor, Ptcout turbo outlet exhaust pressure sensor, Pmap intake manifold pressure sensor, Pair turbo upstream air pressure sensor, Pth throttle upstream pressure sensor

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  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Abstract

Provided is a method for diagnosing the response characteristics of a pressure sensor in the intake system or the exhaust system of an engine, for preventing, in advance, a situation in which the pressure sensor is unable to measure accurately.　A deterioration in response characteristics that occurs in a pressure sensor used to control an engine is diagnosed by comparing a measured index value obtained by measuring, and converting to an index value, pressure sensor signal information, which is a pressure pulsation amplitude generated in the intake system or the exhaust system of the engine as a result of intake or exhaust that accompanies a reciprocating movement of a piston when the engine is running, with a normal index value obtained by index-value conversion from the pressure sensor signal information during normal operation.

Description

エンジン制御に用いられる圧力センサの応答性診断方法Method for diagnosing the responsiveness of the pressure sensor used for engine control
　本発明は、火花点火式エンジンの吸気系および排気系におけるエンジン制御に用いられる圧力センサの応答性診断方法に関するものである。 The present invention relates to a method for diagnosing the responsiveness of a pressure sensor used for engine control in an intake system and an exhaust system of a spark-ignition engine.
　従来、例えば車両などに搭載される火花点火式のエンジンにおいての燃費や走行性能の向上を図る手段として、運転者によるアクセル操作により機械的にスロットルを開閉動作させる代わりに電子式制御システムを用いてスロットルを電子的に開閉動作させる電子制御スロットル制御装置が普及しており、例えば特開平５－２４００７３号公報、特開２００８－３８８７２号公報などに記載されている。 Conventionally, as a means for improving fuel efficiency and driving performance in a spark-ignition engine mounted on a vehicle, for example, an electronic control system has been used instead of mechanically opening and closing the throttle by operating the accelerator by the driver. Electronically controlled throttle control devices that electronically open and close the throttle are widely used, and are described in, for example, JP-A-5-240073 and JP-A-2008-38872.
　そして、前記電子制御スロットル制御装置では、エンジン制御を高精度に行うために電子制御ユニット装置（以下「ＥＣＵ」と言う）によるエンジンの空燃比を制御する目的で、エンジン内に取り入れられる燃料と空気とからなる混合気体の圧力や排気ガスの圧力を測定するために圧力センサが吸気系および排気系に使用されており、殊に、排気系の圧力センサは、排ガスに含まれる、スス、未燃焼燃料、エンジンオイル等の物質によって圧力測定部が塞がれることで圧力を正確に測定できなくなり、故障した場合にはエンジンの制御ができなくなるという問題がある。 Then, in the electronically controlled throttle control device, fuel and air taken into the engine are taken in for the purpose of controlling the air-fuel ratio of the engine by the electronic control unit device (hereinafter referred to as "ECU") in order to perform engine control with high accuracy. Pressure sensors are used in the intake and exhaust systems to measure the pressure of the mixed gas and the pressure of the exhaust gas, and in particular, the pressure sensor of the exhaust system is contained in the exhaust gas, soot and unburned. There is a problem that the pressure cannot be measured accurately because the pressure measuring unit is blocked by a substance such as fuel or engine oil, and the engine cannot be controlled in the event of a failure.
　そこで、圧力センサの構造を変えたり機械的な部品を付設したりすることなくエンジン制御に用いられる圧力センサの応答性診断をする手段として、エンジンをＥＣＵにより診断するものが特開２０１８－７１３７４号公報などに提示されている。 Therefore, as a means for diagnosing the responsiveness of the pressure sensor used for engine control without changing the structure of the pressure sensor or attaching mechanical parts, the engine is diagnosed by the ECU in Japanese Patent Application Laid-Open No. 2018-71374. It is presented in publications and the like.
　これらの公報に提示されたエンジン制御に用いられる圧力センサの応答性診断をする手段は、例えば圧力センサとしてインテークマニホールド圧力センサについて示した図２１のように、エンジンのインテークマニホールド２に配置されたインテークマニホールド圧力センサ〔Ｐｍａｐ〕がＥＣＵ３に接続され、マイクロコンピュータ４に入力されて、インテークマニホールド圧力センサ〔Ｐｍａｐ〕の情報を基にエンジン制御を行っており、同時に前記マイクロコンピュータ４内部にてインテークマニホールド圧力センサ〔Ｐｍａｐ〕の応答性が適切な性能を確保しているかを圧力センサ応答診断回路８にて判断するものであり、ＥＣＵ３においてスロットルバルブ６を閉状態または開状態の一方から他方を経て再び一方に変化させる閉動作を、所定期間ごとに複数回にわたって実施し、１回の前記開閉動作時のインテークマニホールド吸気圧力センサ〔Ｐｍａｐ〕が検出する圧力の差分を圧力変化量として算出し、複数の前記開閉動作ごとの前記圧力変化量を比較することで、インテークマニホールド圧力センサ〔Ｐｍａｐ〕の応答性診断をするものである。 The means for diagnosing the responsiveness of the pressure sensor used for engine control presented in these publications is an intake arranged in the intake manifold 2 of the engine, for example, as shown in FIG. 21 showing the intake manifold pressure sensor as a pressure sensor. A manifold pressure sensor [Pmap] is connected to the ECU 3, input to the microcomputer 4, and engine control is performed based on the information of the intake manifold pressure sensor [Pmap]. At the same time, the intake manifold pressure is performed inside the microcomputer 4. The pressure sensor response diagnosis circuit 8 determines whether or not the responsiveness of the sensor [Pmap] ensures appropriate performance. In the ECU 3, the throttle valve 6 is closed or opened, and then the other and then again. The closing operation is performed a plurality of times at predetermined periods, and the difference in pressure detected by the intake manifold intake pressure sensor [Pmap] during one opening / closing operation is calculated as the pressure change amount, and the plurality of the above-mentioned By comparing the amount of change in pressure for each opening / closing operation, the responsiveness of the intake manifold pressure sensor [Pmap] is diagnosed.
　また、前記図２１に示した診断手段におけるインテークマニホールド圧力センサ〔Ｐｍａｐ〕の応答性診断をする他の手段として、図２２に示したようにインテークマニホールド圧力センサ〔Ｐｍａｐ〕の空気上流部に配置されているスロットルバルブ６の開度センサ情報信号（ＴＨ）を検出してスロットルバルブ６が開き始める時間からインテークマニホールド圧力センサ〔Ｐｍａｐ〕が立ち上がる時間を測定し、この両者の時間差をΔＴ１として応答時間とし、インテークマニホールド圧力センサ〔Ｐｍａｐ〕応答性が劣化した場合、この時間差がΔＴ２となるため、この時間差が広がれば、応答性劣化と判定して故障判定する手段も知られている。 Further, as another means for diagnosing the responsiveness of the intake manifold pressure sensor [Pmap] in the diagnostic means shown in FIG. 21, it is arranged in the air upstream portion of the intake manifold pressure sensor [Pmap] as shown in FIG. The time when the intake manifold pressure sensor [Pmap] starts up is measured from the time when the throttle valve 6 starts to open by detecting the opening sensor information signal (TH) of the throttle valve 6, and the time difference between the two is defined as ΔT1 as the response time. When the responsiveness of the intake manifold pressure sensor [Pmap] deteriorates, this time difference becomes ΔT2. Therefore, if this time difference becomes wide, it is determined that the responsiveness deteriorates and a failure is determined.
　しかしながら、前記従来のＥＣＵ３を用いた圧力センサの応答性診断方法は診断開始のトリガーを、加速、もしくは、減速の過渡的な条件としており、車両における一般公道上での実施においては様々な加速条件があるため一様な過渡条件とならない場合もあり、診断結果にばらつきが多く、正しい圧力センサの応答性の判断が難しいという問題があった。 However, in the conventional method of diagnosing the responsiveness of the pressure sensor using the ECU 3, the trigger for starting the diagnosis is a transient condition of acceleration or deceleration, and various acceleration conditions are used in the implementation on a general public road in a vehicle. Therefore, there is a problem that uniform transient conditions may not be obtained, the diagnostic results vary widely, and it is difficult to judge the correct responsiveness of the pressure sensor.
特開平５－２４００７３号公報Japanese Unexamined Patent Publication No. 5-240073 特開２００８－３８８７２号公報Japanese Unexamined Patent Publication No. 2008-38772 特開２０１８－７１３７４号公報Japanese Unexamined Patent Publication No. 2018-71374
　本発明は、前記課題を解決するためになされたものであり、エンジンの吸気系または排気系におけるエンジン制御に用いられる圧力センサが正確に測定できなくなることを事前に防止するための各種圧力センサの応答性診断方法を提供することを課題とする。 The present invention has been made to solve the above problems, and various pressure sensors for preventing the pressure sensor used for engine control in the intake system or the exhaust system of the engine from being unable to measure accurately in advance. An object of the present invention is to provide a responsiveness diagnostic method.
　前記課題を解決するためになされた本発明は、火花点火式のエンジン制御に用いられるエンジンの吸気系または排気系に備えた圧力センサの応答性劣化診断方法であって、前記エンジンの作動時におけるピストンの往復動に伴う吸気または排気によって前記エンジンの吸気系または排気系に生じる圧力脈動振幅である圧力センサ信号情報を計測して指標値化した計測指標値を、正常時の前記圧力センサ信号情報から指標値化した正常指標値と比較することで前記エンジンの制御に用いられる圧力センサに生じた応答性の劣化を診断することを特徴とする。 The present invention made to solve the above problems is a method for diagnosing responsiveness deterioration of a pressure sensor provided in an intake system or an exhaust system of an engine used for spark ignition type engine control, and is used when the engine is operating. The pressure sensor signal information obtained by measuring the pressure sensor signal information, which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the engine by the intake or exhaust accompanying the reciprocating movement of the piston, and converting it into an index value, is the normal pressure sensor signal information. It is characterized in that deterioration of responsiveness caused in the pressure sensor used for controlling the engine is diagnosed by comparing with the normal index value converted from the above.
　また、本発明において、前記計測したエンジンの吸気系または排気系に生じる圧力脈動振幅である圧力センサ信号情報をエンジン制御装置内部に配置されたアナログフィルタ低域通過フィルタ回路により処理して指標値化することにより前記圧力脈動振幅を適切に処理することができる。 Further, in the present invention, the pressure sensor signal information which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the measured engine is processed by the analog filter low-pass filter circuit arranged inside the engine control device and converted into an index value. By doing so, the pressure pulsation amplitude can be appropriately processed.
　更に、計測したエンジンの吸気系または排気系に生じる圧力脈動振幅である圧力センサ信号情報をエンジン制御装置内部に配置されたデジタル低域通過フィルタ回路により処理して指標値化することにより前記圧力脈動振幅を更に適切に処理することができる。 Further, the pressure sensor signal information, which is the measured pressure pulsation amplitude generated in the intake system or the exhaust system of the engine, is processed by a digital low-pass filter circuit arranged inside the engine control device and converted into an index value to obtain the pressure pulsation. The amplitude can be processed more appropriately.
　更にまた、本発明において、前記デジタル低域通過フィルタ回路による処理を、高周波数振動を有する圧力センサ信号情報から、帯域通過フィルタと絶対値化処理、加重平均処理から圧力センサが検出した高周波数帯の圧力脈動振幅を指標化し、この指標値から圧力センサの応答性を数値化することで確実に処理することができる。 Furthermore, in the present invention, the processing by the digital low-pass filter circuit is performed by the pressure sensor from the pressure sensor signal information having high frequency vibration, the band passing filter and the absolute value processing, and the weighted averaging processing. By indexing the pressure pulsation amplitude of the pressure sensor and quantifying the responsiveness of the pressure sensor from this index value, it can be reliably processed.
　また更に、本発明において、前記得られた指標値をエンジン運転中において最大値を更新し、この最大値を評価することで、特定の運転条件だけではなく、様々な運転条件を１つの指標で応答性劣化の判定を行うことにより計測を少なくすることができる。 Furthermore, in the present invention, by updating the maximum value of the obtained index value during engine operation and evaluating this maximum value, not only specific operating conditions but also various operating conditions can be set as one index. The number of measurements can be reduced by determining the deterioration of responsiveness.
　また、本発明において、前記エンジンの吸気系または排気系に備えた圧力センサが定常運転において圧力脈動が現れるセンサの場合は、加速条件などを経験することなく前記指標値から応答性劣化の判定を行うことが可能である。 Further, in the present invention, when the pressure sensor provided in the intake system or the exhaust system of the engine is a sensor in which pressure pulsation appears in steady operation, the determination of responsiveness deterioration is made from the index value without experiencing acceleration conditions or the like. It is possible to do.
　加えて、本発明において、計測したエンジンの吸気系または排気系に生じる圧力脈動振幅である圧力センサ信号情報をエンジン制御装置内部に配置されたエンジン制御に不要な高域周波数帯を除去する低域通過フィルタ処理により、前記圧力センサ信号情報をエンジン制御に用いる圧力情報として用いることにより、１つの圧力センサで応答性の判断とエンジン制御を両立させることが可能で新たな回路を必要としない。 In addition, in the present invention, the pressure sensor signal information which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the measured engine is used as a low frequency band which is arranged inside the engine control device and removes a high frequency band unnecessary for engine control. By using the pressure sensor signal information as pressure information used for engine control by the pass filter processing, it is possible to achieve both responsiveness determination and engine control with one pressure sensor, and no new circuit is required.
　本発明によれば、圧力センサの構造を複雑化することなく、圧力センサの応答性の異常状態を事前に診断することができ、特に、診断条件として特定の加速・減速条件を必ずしも必要としないばかりか定常運転状態でも圧力センサの応答性が診断できる可能性もあるため、精度が高く、且つ、車両使用状況下で診断実行率の高い圧力センサの応答性能の劣化診断が可能である。 According to the present invention, it is possible to diagnose an abnormal state of responsiveness of a pressure sensor in advance without complicating the structure of the pressure sensor, and in particular, specific acceleration / deceleration conditions are not always required as diagnostic conditions. Not only that, since there is a possibility that the responsiveness of the pressure sensor can be diagnosed even in the steady operation state, it is possible to diagnose the deterioration of the responsiveness of the pressure sensor with high accuracy and high diagnosis execution rate under the vehicle usage conditions.
本発明に適用されるエンジンに搭載される圧力センサの一例を示す配置図。The layout drawing which shows an example of the pressure sensor mounted on the engine applied to this invention. インテークマニホールド圧力センサ〔Ｐｍａｐ〕について本発明を実施した場合の好ましい実施の形態の概略図。FIG. 6 is a schematic view of a preferred embodiment when the present invention is carried out for an intake manifold pressure sensor [Pmap]. 図２に示した実施の形態におけるエンジンが定常運転時（アイドリング運転時）におけるインテークマニホールド圧力センサ〔Ｐｍａｐ〕のピストンの往復動に伴う吸気によって生じる圧力脈動振幅である圧力センサ信号情報である吸気圧力〔ｋＰａ〕の時系列データを示す説明図。Intake pressure, which is pressure sensor signal information, is pressure pulsation amplitude generated by intake air caused by the reciprocating movement of the piston of the intake manifold pressure sensor [Pmap] when the engine in the embodiment shown in FIG. 2 is in steady operation (idling operation). Explanatory drawing which shows the time series data of [kPa]. 図２に示した実施の形態における圧力脈動の指標値化を示す説明図。The explanatory view which shows the index value of the pressure pulsation in the embodiment shown in FIG. 本発明に用いられる圧力センサ信号から振幅を抽出する帯域通過フィルタの設計の一例を示す測定図。The measurement figure which shows an example of the design of the bandpass filter which extracts the amplitude from the pressure sensor signal used in this invention. 本発明における圧力センサの応答性に関する故障診断方法の説明図。The explanatory view of the failure diagnosis method concerning the responsiveness of the pressure sensor in this invention. 正常状態の燃料噴射圧力センサ〔Ｐｉｎｊ〕の本実施の形態における応答性診断の圧力振幅と時系列の測定図。The pressure amplitude and time series measurement figure of the responsiveness diagnosis in this embodiment of the fuel injection pressure sensor [Pinj] in a normal state. 時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた状態の燃料噴射圧力センサ〔Ｐｉｎｊ〕の本実施の形態における応答性診断の圧力振幅と時系列の測定図。The pressure amplitude and time series measurement diagram of the responsiveness diagnosis in this embodiment of the fuel injection pressure sensor [Pinj] in the state where the responsiveness deterioration corresponding to the time constant (Tc) = 0.1 s is given. 時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた状態の燃料噴射圧力センサ〔Ｐｉｎｊ〕の本実施の形態における応答性診断の圧力振幅と時系列の測定図。The pressure amplitude and time series measurement diagram of the responsiveness diagnosis in this embodiment of the fuel injection pressure sensor [Pinj] in a state where the responsiveness is deteriorated corresponding to the time constant (Tc) = 1.0 s. 前記図７に示した特性を示す燃料噴射圧力センサ〔Ｐｉｎｊ〕における本発明の実施の形態における正常時の応答性診断の実行結果を示す測定図。FIG. 6 is a measurement diagram showing an execution result of a responsiveness diagnosis in a normal state according to an embodiment of the present invention in a fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG. 7. 前記図７に示した特性を示す燃料噴射圧力センサ〔Ｐｉｎｊ〕における本発明の実施の形態における時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の応答性診断の実行結果を示す測定図。Execution result of responsiveness diagnosis when responsiveness deterioration corresponding to time constant (Tc) = 0.1 s in the embodiment of the present invention is given to the fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG. The measurement diagram which shows. 前記図７に示した特性を示す燃料噴射圧力センサ〔Ｐｉｎｊ〕における本発明の実施の形態における時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合の応答性診断の実行結果を示す測定図。Execution result of responsiveness diagnosis when responsiveness deterioration corresponding to time constant (Tc) = 1.0 s in the embodiment of the present invention in the fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG. 7 is given. The measurement diagram which shows. 正常状態のインテークマニホールド圧力センサ〔Ｐｍａｐ〕の本実施の形態における応答性診断の圧力振幅と時系列の測定図。FIG. 3 is a measurement diagram of pressure amplitude and time series of responsiveness diagnosis in the present embodiment of the intake manifold pressure sensor [Pmap] in a normal state. 前記図１３に示した特性を示すインテークマニホールド圧力センサ〔Ｐｍａｐ〕における本発明の実施の形態における正常時の応答性診断の実行結果を示す測定図。FIG. 3 is a measurement diagram showing an execution result of a responsiveness diagnosis in a normal state according to an embodiment of the present invention in an intake manifold pressure sensor [Pmap] showing the characteristics shown in FIG. 前記図１３に示した特性を示すインテークマニホールド圧力センサ〔Ｐｍａｐ〕における本発明の実施の形態における時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の応答性診断の実行結果を示す測定図。Execution result of responsiveness diagnosis when responsiveness deterioration corresponding to time constant (Tc) = 0.1s in the embodiment of the present invention is given to the intake manifold pressure sensor [Pmap] showing the characteristics shown in FIG. The measurement diagram which shows. 前記図１３に示した特性を示すインテークマニホールド圧力センサ〔Ｐｍａｐ〕における本発明の実施の形態における時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合の応答性診断の実行結果を示す測定図。Execution result of responsiveness diagnosis when responsiveness deterioration corresponding to time constant (Tc) = 1.0 s in the embodiment of the present invention in the intake manifold pressure sensor [Pmap] showing the characteristics shown in FIG. 13 is given. The measurement diagram which shows. 正常状態のＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕の本実施の形態における応答性診断の圧力振幅と時系列の測定図。The pressure amplitude and time series measurement figure of the responsiveness diagnosis in this embodiment of the EGR valve upstream gas pressure sensor [Pegr] in a normal state. 前記図１７に示した特性を示すＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕における本発明の実施の形態における正常時の応答性診断の実行結果を示す測定図。The measurement figure which shows the execution result of the responsiveness diagnosis at the time of a normal time in embodiment of this invention in the EGR valve upstream gas pressure sensor [Pegr] which shows the characteristic shown in FIG. 前記図１７に示した特性を示すＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕における本発明の実施の形態における時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の応答性診断の実行結果を示す測定図。Responsiveness diagnosis in the case of giving a responsiveness deterioration corresponding to a time constant (Tc) = 0.1s in the embodiment of the present invention in the EGR valve upstream gas pressure sensor [Pegr] showing the characteristics shown in FIG. A measurement diagram showing the execution result. 前記図１７に示した特性を示すＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕における本発明の実施の形態における時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合の応答性診断の実行結果を示す測定図。Responsiveness diagnosis in the case of giving a responsiveness deterioration corresponding to a time constant (Tc) = 1.0 s in the embodiment of the present invention in the EGR valve upstream gas pressure sensor [Pegr] showing the characteristics shown in FIG. A measurement diagram showing the execution result. 従来のインテークマニホールド圧力センサ〔Ｐｍａｐ〕の応答性劣化診断装置についての概略図。The schematic diagram of the responsive deterioration diagnostic apparatus of the conventional intake manifold pressure sensor [Pmap]. 図２１に示した圧力センサの応答性劣化診断装置による診断方法の一例を示す説明図。The explanatory view which shows an example of the diagnosis method by the responsiveness deterioration diagnosis apparatus of the pressure sensor shown in FIG.
　以下に、図面を参照しながら本発明を実施するための形態を説明する。 Hereinafter, a mode for carrying out the present invention will be described with reference to the drawings.
　尚、本発明は、図１に示した、例えば燃費改善等の目的で、燃料と混合する気体として排気ガスを用いる排ガス循環（Ｅｘｈａｕｓｔ　Ｇａｓ　Ｒｅｃｉｒｃｕｌａｔｉｏｎ，以下「ＥＧＲ」と言う）装置を備えたエンジンのように、排気系の圧力センサであるターボ出口排気圧力センサ〔Ｐｔｃｏｕｔ〕、ＥＧＲバルブ上流圧力センサ〔Ｐｅｇｒ〕などだけでなく、吸気系の圧力センサであるインテークマニホールド圧力センサ〔Ｐｍａｐ〕、ターボ上流空気圧力センサ〔Ｐａｉｒ〕、スロットル上流圧力センサ〔Ｐｔｈ〕や燃料噴射圧力センサ〔Ｐｉｎｊ〕などエンジン制御に用いられる各所に使用される圧力センサについても同様に実施することができるものである。 The present invention relates to an engine provided with an exhaust gas recirculation (Exhaust Gas Recirculation, hereinafter referred to as "EGR") device that uses exhaust gas as a gas to be mixed with fuel, for example, for the purpose of improving fuel efficiency, as shown in FIG. As described above, not only the exhaust system pressure sensor such as the turbo outlet exhaust pressure sensor [Ptcout] and the EGR valve upstream pressure sensor [Pegr], but also the intake system pressure sensor such as the intake manifold pressure sensor [Pmap] and the turbo upstream air. The same can be applied to pressure sensors used in various places used for engine control, such as a pressure sensor [Pair], an upstream throttle pressure sensor [Pth], and a fuel injection pressure sensor [Pinj].
　図２は、前記各圧力センサの内で、エンジン１のインテークマニホールド２に設置されたインテークマニホールド圧力センサ〔Ｐｍａｐ〕について本発明を実施した場合の好ましい実施の形態を示すものであり、インテークマニホールド圧力センサ〔Ｐｍａｐ〕の情報はワイヤーハーネスを介してＥＣＵ３に入力される。 FIG. 2 shows a preferred embodiment of the intake manifold pressure sensor [Pmap] installed in the intake manifold 2 of the engine 1 among the pressure sensors when the present invention is implemented, and shows the intake manifold pressure. The information of the sensor [Pmap] is input to the ECU 3 via the wire harness.
　ここで、一般的にＥＣＵ３にはエンジン制御で不要となるノイズ成分を除去するための電子部品で構成されたアナログフィルタ回路９とソフトウエアで構成されたデジタルフィルタ処理回路１１が配備されているが、今回の技術に用いるフィルタ部は従来仕様と比較して、エンジン脈動成分を検出するために高周波数帯が観測可能なアナログフィルタ回路１０とデジタルフィルタ回路１３とからなるフィルタ装置を備えており、この情報を元に応答性劣化の故障診断を行うが、デジタルフィルタ回路１２を並列に設け診断応答処理とは別のフィルタ処理を実施した情報を元にエンジン制御処理回路５により実施することにより、センサ入力回路を変更しても従来と変わらないエンジン制御が可能となる。 Here, in general, the ECU 3 is provided with an analog filter circuit 9 composed of electronic components for removing noise components unnecessary for engine control and a digital filter processing circuit 11 composed of software. Compared with the conventional specifications, the filter unit used in this technology is equipped with a filter device consisting of an analog filter circuit 10 and a digital filter circuit 13 that can observe a high frequency band in order to detect engine pulsation components. A failure diagnosis of responsiveness deterioration is performed based on this information, but by performing the failure diagnosis by the engine control processing circuit 5 based on the information obtained by providing the digital filter circuits 12 in parallel and performing the filter processing different from the diagnostic response processing. Even if the sensor input circuit is changed, engine control that is the same as before is possible.
　次に、本実施の形態の圧力センサの応答性診断の原理についてインテークマニホールド圧力センサ〔Ｐｍａｐ〕を例にして説明する。 Next, the principle of responsiveness diagnosis of the pressure sensor of the present embodiment will be described by taking the intake manifold pressure sensor [Pmap] as an example.
　図３はエンジンが定常運転時（アイドリング運転時）におけるインテークマニホールド圧力センサ〔Ｐｍａｐ〕のピストンの往復動に伴う吸気によって生じる圧力脈動振幅からなる圧力センサ信号情報である吸気圧力〔ｋＰａ〕の時系列データを示すものである。 FIG. 3 shows a time series of intake pressure [kPa], which is pressure sensor signal information consisting of pressure pulsation amplitude generated by intake air accompanying the reciprocating movement of the piston of the intake manifold pressure sensor [Pmap] when the engine is in steady operation (idling operation). It shows the data.
　ここで、エンジンは往復動機関であるため、間欠的な吸気・排気作用により脈動が少なからず発生するため、図３に示すように定常値よりも高いか若しくは低い圧力である圧力脈動として必ず観測でき、この圧力脈動は高周波数であるため、圧力センサの応答性が劣化するとこの振幅が見かけ上に減少するように観測される。本発明はこの点に着目したものであり、前記圧力脈動を観測して指標値化し、これを正常時と比較することで圧力セン
サの応答性劣化を判別可能するものである。 Here, since the engine is a reciprocating engine, pulsation is not a little generated due to intermittent intake / exhaust action, so it is always observed as pressure pulsation that is higher or lower than the steady value as shown in FIG. Since this pressure pulsation has a high frequency, it is observed that this amplitude apparently decreases when the responsiveness of the pressure sensor deteriorates. The present invention focuses on this point, and it is possible to discriminate the deterioration of the responsiveness of the pressure sensor by observing the pressure pulsation, converting it into an index value, and comparing this with the normal state.
　次に、本実施の形態における圧力脈動の指標値化について図４を用いて説明する。 Next, the index value of the pressure pulsation in the present embodiment will be described with reference to FIG.
　図４に示すように、本実施の形態における診断対象となる各圧力センサ信号が、帯域通過フィルタ、絶対値処理を経て、圧力センサ振幅値（ＲＥＳ＿ＡＭＰ）となる過程を経るが、前記圧力センサ振幅値（ＲＥＳ＿ＡＭＰ）には定常で発生する圧力脈動などに加えて、加減速時の過渡変化なども含まれた高周波数成分として重畳されてしまうため、加重平均処理によって適切な平滑化処理を行い、応答を数値として抽出し、これを特定のドライビング・サイクル（例えば、エンジン始動から次のエンジン始動までの運転中の全区間）において、最大値更新処理により最大値を更新することにより、比較的簡単な方法で当該圧力センサの最大応答を指標値として数値化することで圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）を求めることができる。 As shown in FIG. 4, each pressure sensor signal to be diagnosed in the present embodiment goes through a process of becoming a pressure sensor amplitude value (RES_AMP) through a band passage filter and absolute value processing, and the pressure sensor amplitude Since the value (RES_AMP) is superimposed as a high frequency component that includes not only the pressure pulsation that occurs constantly but also the transient change during acceleration / deceleration, appropriate smoothing processing is performed by weighted averaging processing. It is relatively easy to extract the response as a numerical value and update the maximum value by the maximum value update process in a specific driving cycle (for example, the entire section during operation from the engine start to the next engine start). The pressure sensor responsiveness deterioration index (RES_IDX) can be obtained by quantifying the maximum response of the pressure sensor as an index value by various methods.
　ここで、各圧力センサ信号から振幅を抽出する帯域通過フィルタの設計が重要になるが、図５にその一例を示す。低域は１Ｈｚ以下をカットし、高域は１０Ｈｚ以上をカットすることで、応答性診断に不要なＤＣ成分と、電気的なノイズ成分を除去することで、検出精度を向上させることを特徴としている。尚、これらの帯域通過フィルタは、一般的な有限インパルス応答（ＦＩＲ）フィルタや、無限インパルス応答フィルタ（ＩＩＲ）フィルタの技術を利用することで、比較的少ないリソースでマイクロコンピュータに実装が可能であるのは説明するまでもない。 Here, it is important to design a bandpass filter that extracts the amplitude from each pressure sensor signal, and Fig. 5 shows an example. It is characterized by improving the detection accuracy by removing DC components and electrical noise components that are unnecessary for responsiveness diagnosis by cutting 1 Hz or less in the low range and 10 Hz or more in the high range. There is. These bandpass filters can be implemented in a microcomputer with a relatively small amount of resources by using general finite impulse response (FIR) filter or infinite impulse response filter (IIR) filter technology. Needless to say.
　ここで求められた指標値は圧力センサの応答性が高いほど、高い指標値を示すが、前述のように、圧力センサに発生する圧力脈動によって指標値が変化するため、運転条件によって指標値が影響を受けることになる。 The higher the responsiveness of the pressure sensor, the higher the index value obtained here. However, as described above, the index value changes depending on the pressure pulsation generated in the pressure sensor, so that the index value changes depending on the operating conditions. Will be affected.
　そこで、例えば図６に示すように、エンジンの回転情報〔Ｎｅ〕とアクセル開度情報〔ＡＰＳ〕から、どの運転条件を、どれぐらいの時間経験したかをカウントし、そのカウントの合計値から、予め想定された運転条件を経験したと判断することができる。 Therefore, for example, as shown in FIG. 6, from the engine rotation information [Ne] and the accelerator opening information [APS], which driving condition is experienced and for how long is counted, and from the total value of the counts, It can be determined that the operation conditions assumed in advance have been experienced.
　更に詳細に説明すると、経験したことを示すフラグ情報を算出する判定処理を実施し、このフラグ情報が「真」（Ｔｒｕｅ）であるとき、前述した圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）を求めることができ、圧力センサの応答性劣化指標（ＲＥＳ＿ＩＤＸ）による判定を行うことで正しい応答性の判断が可能となる。 More specifically, a determination process for calculating flag information indicating experience is performed, and when this flag information is "true", the pressure sensor responsiveness deterioration index (RES_IDX) described above is obtained. It is possible to judge the correct responsiveness by making a judgment based on the responsiveness deterioration index (RES_IDX) of the pressure sensor.
　そして、前記圧力センサの応答性が正常ならば、圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）は高い値を示し、応答性が劣化していれば、圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）は低い値を示す。 If the responsiveness of the pressure sensor is normal, the pressure sensor responsiveness deterioration index (RES_IDX) shows a high value, and if the responsiveness deteriorates, the pressure sensor responsiveness deterioration index (RES_IDX) shows a low value. Shown.
　従って、前記圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）の値が応答性故障診断閾値よりも低く、且つ、運転条件経験フラグが「真」（Ｔｒｕｅ）として論理積が判定した場合には圧力センサ応答性に故障に繋がる劣化があると判断し、前記圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）の値が応答性故障診断閾値よりも高く、且つ、運転条件経験フラグが「真」（Ｔｒｕｅ）であると論理積が判定した場合には、センサ応答性は正常と判断することで、圧力センサの応答性に関する故障診断が実施される。 Therefore, when the value of the pressure sensor responsiveness deterioration index (RES_IDX) is lower than the responsiveness failure diagnosis threshold and the logical product is determined as "true" (True) of the operating condition experience flag, the pressure sensor responsiveness is determined. It is logical that the value of the pressure sensor responsiveness deterioration index (RES_IDX) is higher than the responsiveness failure diagnosis threshold and the operating condition experience flag is "true" (True). When the product is determined, the sensor responsiveness is determined to be normal, and a failure diagnosis regarding the responsiveness of the pressure sensor is performed.
　次に、本実施の形態の作用について例えば燃料噴射圧力センサ〔Ｐｉｎｊ〕の場合について説明する。 Next, the operation of this embodiment will be described, for example, in the case of a fuel injection pressure sensor [Pinj].
　図７は燃料噴射圧力センサ〔Ｐｉｎｊ〕の応答性が正常な状態においてエンジン台上でＷｏｒｌｄ－ｗｉｄｅ　Ｈａｍｏｎｉｚｅｄ　Ｔｒａｎｓｉｅｎｔ　Ｃｙｃｌｅ試験モード（以下「ＷＨＴＣ試験モード」と言う）で運転したときのデータを示すもので、上段のグラフは燃料噴射圧力センサ〔Ｐｉｎｊ〕からの圧力脈動〔ｋＰａ〕の時系列〔ｓ（秒）〕についてのデータを示しており、エンジン停止状態から始動して、ＷＨＴＣ試験モードで定められた各々の定常および過渡的な運転を実施している。 FIG. 7 shows the data when the fuel injection pressure sensor [Pinj] is operated in the World-wide Hamonized Transient Cycle test mode (hereinafter referred to as "WHTC test mode") on the engine table in a normal state. , The upper graph shows the data about the time series [s (seconds)] of the pressure pulsation [kPa] from the fuel injection pressure sensor [Pinj], which is determined in the WHTC test mode starting from the engine stopped state. Each steady and transient operation is carried out.
　前記図７における上段のグラフにおいて着目するところは、経過時間３００（ｓ）前後のアイドル運転状態において燃料噴射バルブ作動により比較的大きな圧力脈動が発生し、燃料噴射圧力センサ値がこれに呼応して大きく振動する様子が観測できる点である。 What is of interest in the upper graph in FIG. 7 is that a relatively large pressure pulsation is generated by the operation of the fuel injection valve in the idle operation state with an elapsed time of about 300 (s), and the fuel injection pressure sensor value responds to this. It is a point where you can observe the state of large vibration.
　図７における下段に示したグラフは、前記上段のグラフにおいて着目されるアイドル運転状態において燃料噴射バルブ作動により観測される振動成分である燃料噴射圧力センサ信号に短時間高速フーリエ変換を施したものを、横軸を時間軸とし、縦軸を周波数帯として表したものである。 The graph shown in the lower part of FIG. 7 shows the fuel injection pressure sensor signal, which is a vibration component observed by the operation of the fuel injection valve in the idle operation state of interest in the upper graph, subjected to a short-time fast Fourier transform. , The horizontal axis is the time axis, and the vertical axis is the frequency band.
　尚、図７における中段のグラフは前記下段のグラフにおける周波数帯の振幅を濃淡によって表したものであり、薄い色ほど大きな振動が存在していることを示している。 The middle graph in FIG. 7 shows the amplitude of the frequency band in the lower graph by shading, and the lighter the color, the larger the vibration.
　そして、前記図７の下段のグラフからの解析結果によると、前記アイドル運転においては、１０Ｈｚ付近に燃料噴射圧力センサ〔Ｐｉｎｊ〕の圧力振幅が表れていることが解り、これに加えて、試験モード運転の後半の定常運転にも燃料噴射圧力センサ〔Ｐｉｎｊ〕の圧力振幅に大きな振動成分が観測されるが、これは３０Ｈｚ程度の高調波が主成分となっていることが解る。 Then, according to the analysis result from the lower graph of FIG. 7, it is found that the pressure amplitude of the fuel injection pressure sensor [Pinj] appears in the vicinity of 10 Hz in the idle operation, and in addition to this, the test mode A large vibration component is also observed in the pressure amplitude of the fuel injection pressure sensor [Pinj] in the steady operation in the latter half of the operation, and it can be seen that this is mainly composed of harmonics of about 30 Hz.
　図８および図９は前記図７に示した特性を示す燃料噴射圧力センサ〔Ｐｉｎｊ〕の燃料噴射圧力センサ信号において意図的に燃料噴射圧力センサ〔Ｐｉｎｊ〕の応答性の劣化を与えた結果を示すものであり、図８は時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合を示すもの、図９は更に燃料噴射圧力センサ〔Ｐｉｎｊ〕の応答性の劣化を与えた時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合を示すものである。 8 and 9 show the results of intentionally deteriorating the responsiveness of the fuel injection pressure sensor [Pinj] in the fuel injection pressure sensor signal of the fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG. 7. FIG. 8 shows a case where the responsiveness deterioration corresponding to the time constant (Tc) = 0.1s is given, and FIG. 9 shows the case where the responsiveness deterioration of the fuel injection pressure sensor [Pinj] is further given. It shows the case where the responsiveness deterioration corresponding to the constant (Tc) = 1.0s is given.
　図８に示した周波数分布図によると、前記図７に示した正常時に表れていたアイドル条件での燃料噴射圧力センサ信号が減少することが観測される。これは燃料噴射圧力センサ〔Ｐｉｎｊ〕の応答性が劣化したことにより、高周波数成分が捉えられなくなった結果であり、図９に示した燃料噴射圧力センサ〔Ｐｉｎｊ〕の応答性を更に劣化させた周波数分布図の場合には、アイドル条件での燃料噴射圧力センサ信号が更に減少することが観測される。 According to the frequency distribution diagram shown in FIG. 8, it is observed that the fuel injection pressure sensor signal under the idle condition, which appeared in the normal state shown in FIG. 7, decreases. This is a result that high frequency components cannot be captured due to the deterioration of the responsiveness of the fuel injection pressure sensor [Pinj], and the responsiveness of the fuel injection pressure sensor [Pinj] shown in FIG. 9 is further deteriorated. In the case of the frequency distribution map, it is observed that the fuel injection pressure sensor signal under the idle condition is further reduced.
　これらのことから、アイドル条件以外の運転条件においても全体的に燃料噴射圧力センサの応答性が劣化すると高周波数成分が減少していることが解る。 From these facts, it can be seen that the high frequency component decreases when the responsiveness of the fuel injection pressure sensor deteriorates as a whole even under operating conditions other than the idle condition.
　図１０乃至図１２は、前記図７に示した特性を示す燃料噴射圧力センサ〔Ｐｉｎｊ〕における本発明の実施の形態における応答性診断の実行結果を示すものであり、図１０は正常状態の診断実行結果を、図１１は時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の診断実行結果を、図１２は時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合の診断実行結果を、それぞれ示すものである。 10 to 12 show the execution result of the responsiveness diagnosis according to the embodiment of the present invention in the fuel injection pressure sensor [Pinj] showing the characteristics shown in FIG. 7, and FIG. 10 shows the diagnosis of the normal state. FIG. 11 shows the execution result, FIG. 11 shows the diagnosis execution result when the responsiveness deterioration corresponding to the time constant (Tc) = 0.1s is given, and FIG. 12 shows the responsiveness deterioration corresponding to the time constant (Tc) = 1.0s. The diagnosis execution result when is given is shown respectively.
　そして、正常状態の診断実行結果を示す図１０によると、アイドル運転時における燃料噴射圧力センサ〔Ｐｉｎｊ〕からの圧力脈動〔ｋＰａ〕に呼応して、診断プログラムで計算された圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）が０以上の定常値を示すことが観察され、このことからアイドル運転時において圧力振動が定常的に検出されていることが解る。 Then, according to FIG. 10 showing the diagnosis execution result in the normal state, the amplitude value of the pressure sensor calculated by the diagnostic program in response to the pressure pulsation [kPa] from the fuel injection pressure sensor [Pinj] during idle operation ( It is observed that RES_AMP) shows a steady value of 0 or more, which indicates that pressure vibration is constantly detected during idle operation.
　また、図１１に示したように、時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合には燃料噴射圧力センサ〔Ｐｉｎｊ〕からの圧力脈動〔ｋＰａ〕に呼応して、診断プログラムで計算された圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）は少なくなり、ほぼ０になっていることが解る。このようにアイドル運転時における燃料噴射圧力センサ〔Ｐｉｎｊ〕からの圧力脈動〔ｋＰａ〕に呼応して、診断プログラムで計算された圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）を比較することで、時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を判別することが可能になることが解る。 Further, as shown in FIG. 11, when the responsiveness deterioration corresponding to the time constant (Tc) = 0.1 s is given, in response to the pressure pulsation [kPa] from the fuel injection pressure sensor [Pinj], It can be seen that the amplitude value (RES_AMP) of the pressure sensor calculated by the diagnostic program decreases and becomes almost 0. In this way, by comparing the amplitude value (RES_AMP) of the pressure sensor calculated by the diagnostic program in response to the pressure pulsation [kPa] from the fuel injection pressure sensor [Pinj] during idle operation, the time constant (Tc) ) = It can be seen that it becomes possible to discriminate the responsiveness deterioration corresponding to 0.1 s.
　更に、図１２に示したように、時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合には燃料噴射圧力センサ〔Ｐｉｎｊ〕からの圧力脈動〔ｋＰａ〕に呼応して、診断プログラムで計算された圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）も０付近を示すため、これだけでは前記図１１に示した時定数（Ｔｃ）＝０．１ｓに相当する場合と区別ができない。 Further, as shown in FIG. 12, when the responsiveness deterioration corresponding to the time constant (Tc) = 1.0 s is given, in response to the pressure pulsation [kPa] from the fuel injection pressure sensor [Pinj], Since the pressure sensor amplitude value (RES_AMP) calculated by the diagnostic program also shows a vicinity of 0, it cannot be distinguished from the case corresponding to the time constant (Tc) = 0.1 s shown in FIG. 11 by itself.
　しかしながら、アイドルの定常運転だけではなく、加速時における燃料噴射圧力の立ち上がりも遅れるため、前記圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）のピークも低くなる傾向にあり、これによって前記圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）の値が低下傾向を示すことが解る。 However, not only the steady operation of the idle but also the rise of the fuel injection pressure at the time of acceleration is delayed, so that the peak of the amplitude value (RES_AMP) of the pressure sensor tends to be low, which causes the pressure sensor responsiveness deterioration index ( It can be seen that the value of RES_IDX) shows a downward trend.
　そこで、前記圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）の情報を利用することで時定数（Ｔｃ）＝０．１ｓ以上の応答性劣化も検出することが可能となり、この圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）は圧力センサの持つ最大応答を数値化するため、診断が起動したエンジン始動直後は小さい値を示すが、様々な圧力振動や過渡条件を経験すると、徐々に大きな値へと変化する。 Therefore, by using the information of the pressure sensor responsiveness deterioration index (RES_IDX), it becomes possible to detect the responsiveness deterioration of the time constant (Tc) = 0.1 s or more, and this pressure sensor responsiveness deterioration index (RES_IDX) can be detected. ) Indicates a small value immediately after the engine is started when the diagnosis is started because the maximum response of the pressure sensor is quantified, but it gradually changes to a large value when various pressure vibrations and transient conditions are experienced.
　このように、今回のＷＨＴＣ試験モード運転では経過時間が約６００ｓでほぼ一定値に飽和する傾向にある。これについては前述した診断プログラムのうち、運転領域経験判定処理のフラグ情報を活用することで、様々な運転条件を経験したことが解るため、これによって判断が可能となる。 As described above, in the WHTC test mode operation this time, the elapsed time tends to be saturated to almost a constant value in about 600 s. This can be determined by utilizing the flag information of the driving area experience determination process in the above-mentioned diagnostic program because it is known that various operating conditions have been experienced.
　図１３乃至図１６は、圧力センサとしてインテークマニホールド圧力センサ〔Ｐｍａｐ〕を採用した場合の本発明における実施の形態の作用について説明する。 13 to 16 show the operation of the embodiment of the present invention when the intake manifold pressure sensor [Pmap] is adopted as the pressure sensor.
　図１３は、インテークマニホールド圧力センサ〔Ｐｍａｐ〕が正常な状態でのエンジン台上ＷＨＴＣ試験モードで運転したときの本発明の実施の形態であるデータを示すものであり、上段のグラフはインテークマニホールド圧力センサ〔Ｐｍａｐ〕からの圧力脈動〔ｋＰａ〕の時系列〔ｓ（秒）〕についてのデータを示しており、エンジン停止状態から始動して、ＷＨＴＣ試験モードで定められた各々の定常および過渡的な運転を実施している。 FIG. 13 shows the data according to the embodiment of the present invention when the intake manifold pressure sensor [Pmap] is operated in the WHTC test mode on the engine table in a normal state, and the upper graph shows the intake manifold pressure. It shows the data for the time series [s (seconds)] of the pressure pulsation [kPa] from the sensor [Pmap], starting from the engine stopped state and each steady and transient defined in the WHTC test mode. The operation is being carried out.
　図１３の経過時間３００ｓ前後のアイドル運転状態に着目すると、圧力脈動により３００Ｈｚ程度の高調波が観測できるが、振幅が小さく、劣化判定はできない。また、モード後半の高回転・高負荷の定常運転領域も同様に圧力振幅による高調波成分は観測できるが、振幅が小さく、この情報だけでは劣化の判定はできない。 Focusing on the idle operation state with an elapsed time of about 300 s in FIG. 13, harmonics of about 300 Hz can be observed due to pressure pulsation, but the amplitude is small and deterioration cannot be determined. Further, in the steady operation region of high rotation and high load in the latter half of the mode, the harmonic component due to the pressure amplitude can be observed in the same manner, but the amplitude is small and the deterioration cannot be judged only by this information.
　次に、本発明において、圧力センサとして、インテークマニホールド圧力センサ〔Ｐｉｎｔ〕を用いた場合の本発明の実施の形態の観測結果を図１４乃至図１６に示す。図１４は正常状態の診断実行結果を、図１５は時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の診断実行結果を、図１６は時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合の診断実行結果を、それぞれ示すものである。 Next, FIGS. 14 to 16 show the observation results of the embodiment of the present invention when the intake manifold pressure sensor [Pint] is used as the pressure sensor in the present invention. FIG. 14 shows the diagnosis execution result in the normal state, FIG. 15 shows the diagnosis execution result when the responsiveness deterioration corresponding to the time constant (Tc) = 0.1s is given, and FIG. 16 shows the diagnosis execution result when the time constant (Tc) = 1. The results of executing the diagnosis when the responsiveness deterioration corresponding to 0 s is given are shown respectively.
　正常なインテークマニホールド圧力センサ〔Ｐｍａｐ〕での応答性能診断の実行結果である図１４によると、圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）はアイドル状態で０付近を示しており、後半の高回転・高負荷の定常運転領域においても同様に小さいことから、圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）の情報を利用した応答性劣化判定できないことが解る。ここで、診断プログラムで計算される圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）の情報に着目すると、インテークマニホールド圧力センサ〔Ｐｍａｐ〕の圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）は試験モード終了時点で８０付近まで上昇していることが解る。 According to FIG. 14, which is the execution result of the response performance diagnosis with the normal intake manifold pressure sensor [Pmap], the amplitude value (RES_AMP) of the pressure sensor shows near 0 in the idle state, and the high rotation and high load in the latter half. Since it is also small in the steady operation region of the above, it can be understood that the responsiveness deterioration cannot be determined using the information of the pressure sensor responsiveness deterioration index (RES_IDX). Focusing on the information of the pressure sensor responsiveness deterioration index (RES_IDX) calculated by the diagnostic program, the pressure sensor responsiveness deterioration index (RES_IDX) of the intake manifold pressure sensor [Pmap] is up to around 80 at the end of the test mode. You can see that it is rising.
　更に、時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の診断実行結果を示す図１５においても、圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）およびインテークマニホールド圧力センサ〔Ｐｍａｐ〕の圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）ともに前記図１２に示した圧力センサ正常時と差異がなく、応答性劣化判定はできないが時定数（Ｔｃ）＝０．１ｓ程度の劣化はエミッションに影響を与えないため判定できなくても問題はない。 Further, also in FIG. 15 showing the diagnosis execution result when the responsiveness deterioration corresponding to the time constant (Tc) = 0.1 s is given, the amplitude value (RES_AMP) of the pressure sensor and the pressure of the intake manifold pressure sensor [Pmap] are also shown. The sensor responsiveness deterioration index (RES_IDX) is not different from that of the normal pressure sensor shown in FIG. 12, and the responsiveness deterioration cannot be determined, but the deterioration of the time constant (Tc) = 0.1 s does not affect the emission. Therefore, there is no problem even if it cannot be judged.
　更にまた、時定数（Ｔｃ）＝１．０ｓに相当する更に劣化させた応答性を与えた場合の診断実行結果を示す図１６によると、時定数（Ｔｃ）＝１．０ｓに相当する劣化をさせた場合においてもアイドル状態と後半の高回転・高負荷の定常運転領域の圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）は正常なインテークマニホールド圧力センサと差異が無く、圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）では応答性劣化は判別できない。 Furthermore, according to FIG. 16 showing the results of executing the diagnosis when a further deteriorated responsiveness corresponding to the time constant (Tc) = 1.0 s is given, the deterioration corresponding to the time constant (Tc) = 1.0 s is shown. The amplitude value (RES_AMP) of the pressure sensor in the idle state and the high-speed / high-load steady-state operation region in the latter half is not different from that of the normal intake manifold pressure sensor, and the amplitude value of the pressure sensor (RES_AMP) responds even when the pressure sensor is operated. Sexual deterioration cannot be determined.
　しかしながら、圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）に着目すると、圧力センサの劣化が進んだため圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）のピーク値が低くなり、試験モード終了時点では５０付近で留まっていることが観測され、これを圧力センサ応答性劣化指標（ＲＥＳ＿ＩＤＸ）の正常なセンサとの差異を比較することで、時定数（Ｔｃ）＝１．０ｓ以上の応答性劣化を検出することが可能となる。尚、判定手段については前記図１０乃至図１３に示した燃料噴射圧力センサ〔Ｐｉｎｊ〕の実施の形態の場合と同様であり、説明については省略する。 However, focusing on the pressure sensor responsiveness deterioration index (RES_IDX), the peak value of the amplitude value (RES_AMP) of the pressure sensor becomes low due to the deterioration of the pressure sensor, and it remains around 50 at the end of the test mode. Is observed, and by comparing the difference between the pressure sensor responsiveness deterioration index (RES_IDX) and a normal sensor, it becomes possible to detect responsiveness deterioration with a time constant (Tc) = 1.0 s or more. .. The determination means is the same as that of the embodiment of the fuel injection pressure sensor [Pinj] shown in FIGS. 10 to 13, and the description thereof will be omitted.
　更に、図１７乃至図２０に、圧力センサとしてＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕を採用した場合の発明の実施の形態における作用について説明する。 Further, FIGS. 17 to 20 will explain the operation in the embodiment of the invention when the EGR valve upstream gas pressure sensor [Pegr] is adopted as the pressure sensor.
　図１７は、ＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕が正常な状態でエンジン台上ＷＨＴＣ試験モードを運転したときのデータを示ものであり、上段のグラフはＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕からの圧力脈動〔ｋＰａ〕の時系列データを示し、グラフ下段は上段と同一時間軸におけるＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕の周波数と振幅成分を示す。 FIG. 17 shows the data when the WHTC test mode on the engine table is operated in the normal state of the EGR valve upstream gas pressure sensor [Pegr], and the upper graph is from the EGR valve upstream gas pressure sensor [Pegr]. The time series data of the pressure pulsation [kPa] is shown, and the lower part of the graph shows the frequency and amplitude component of the EGR valve upstream gas pressure sensor [Pegr] on the same time axis as the upper part.
　図１７によると、前記ＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕は、アイドル運転で４０Ｈｚ程度の高調波が観測できるが、振幅は少なく、モード後半の高回転・高負荷の定常運転域で比較的大きな圧力振幅が観測できる。 According to FIG. 17, the EGR valve upstream gas pressure sensor [Pegr] can observe harmonics of about 40 Hz in idle operation, but the amplitude is small and relatively large in the high rotation and high load steady operation range in the latter half of the mode. The pressure amplitude can be observed.
　次に、図１７に示した圧力振動を有するＥＧＲバルブ上流ガス圧力センサ〔Ｐｅｇｒ〕について本発明を実施した場合の応答性診断の実行結果を図１８乃至図２０に示す。尚、図１８は正常状態の診断実行結果を、図１９は時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の診断実行結果を、図２０は時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合の診断実行結果を、それぞれ示すものである。 Next, FIGS. 18 to 20 show the execution results of the responsiveness diagnosis when the present invention is carried out for the EGR valve upstream gas pressure sensor [Pegr] having the pressure vibration shown in FIG. It should be noted that FIG. 18 shows the diagnosis execution result in the normal state, FIG. 19 shows the diagnosis execution result when the responsiveness deterioration corresponding to the time constant (Tc) = 0.1s is given, and FIG. 20 shows the diagnosis execution result when the time constant (Tc) = 0.1s. The diagnosis execution results when the responsiveness deterioration corresponding to 1.0 s is given are shown respectively.
　そして、正常状態の診断結果を示す図１８の診断実行結果によると、アイドル運転では圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）が０であり、図１９に示した時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の診断実行結果および図２０は時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合の診断実行結果も圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）が０であり、アイドル運転だけで劣化判別はできない。 According to the diagnosis execution result of FIG. 18 showing the diagnosis result of the normal state, the amplitude value (RES_AMP) of the pressure sensor is 0 in the idle operation, which corresponds to the time constant (Tc) = 0.1 s shown in FIG. The diagnostic execution result when the responsiveness deterioration is given and the diagnosis execution result when the responsiveness deterioration corresponding to the time constant (Tc) = 1.0 s is also shown in FIG. 20, the amplitude value (RES_AMP) of the pressure sensor is 0. Therefore, deterioration cannot be determined only by idle operation.
　一方、モード後半の高回転・高負荷の定常運転域においては、正常状態の診断結果を示す図１８の診断実行結果では０以上の圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）を示すことが観察できるが、図１９に示した時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を与えた場合の診断実行結果では圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）は小さくなり、正常状態時と比較して時定数（Ｔｃ）＝０．１ｓに相当する応答性劣化を判定することが可能になることが解る。 On the other hand, in the high rotation / high load steady operation range in the latter half of the mode, it can be observed that the amplitude value (RES_AMP) of the pressure sensor of 0 or more is shown in the diagnosis execution result of FIG. 18, which shows the diagnosis result of the normal state. In the diagnosis execution result when the response deterioration corresponding to the time constant (Tc) = 0.1 s shown in FIG. 19 is given, the amplitude value (RES_AMP) of the pressure sensor becomes smaller, and the time constant is compared with the normal state. It can be seen that it is possible to determine the responsiveness deterioration corresponding to (Tc) = 0.1s.
　また、図２０に示した時定数（Ｔｃ）＝１．０ｓに相当する応答性劣化を与えた場合の診断実行結果では、圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）は殆ど変化しなくなり、圧力センサの振幅値（ＲＥＳ＿ＡＭＰ）での判定は難しい。尚、判定手段については前記図１０乃至図１２に示した燃料噴射圧力センサ〔Ｐｉｎｊ〕の実施の形態の場合と同様であり、説明については省略する。 Further, in the diagnosis execution result when the responsiveness deterioration corresponding to the time constant (Tc) = 1.0 s shown in FIG. 20 is given, the amplitude value (RES_AMP) of the pressure sensor hardly changes, and the amplitude of the pressure sensor. Judgment by value (RES_AMP) is difficult. The determination means is the same as that of the embodiment of the fuel injection pressure sensor [Pinj] shown in FIGS. 10 to 12, and the description thereof will be omitted.
　以上のように、各本実施の形態は、圧力センサに重畳される脈動成分を計測し、この圧力振幅を簡単なフィルタ信号処理により指標値化し、運転条件の経験フラグと組み合わせて判定することで、診断条件に特定の加速・減速条件が必ずしも必要にはならず、加えて、定常運転状態でも圧力センサの応答性が診断できる可能性もあるため、精度が高く、かつ、車両使用状況下で診断実行率の高い圧力センサの応答性能の劣化診断の提供が可能である。 As described above, in each of the present embodiments, the pulsating component superimposed on the pressure sensor is measured, the pressure amplitude is converted into an index value by a simple filter signal processing, and the pressure is determined in combination with the experience flag of the operating condition. , Specific acceleration / deceleration conditions are not always required for diagnostic conditions, and in addition, the responsiveness of the pressure sensor may be diagnosed even in steady operation conditions, so accuracy is high and under vehicle usage conditions. It is possible to provide a deterioration diagnosis of the response performance of a pressure sensor having a high diagnosis execution rate.
　１　エンジン、２　インテークマニホールド、３　ＥＣＵ、４　マイクロコンピュータ、５　エンジン制御処理回路、６　スロットルバルブ、７　スロットルバルブ開度センサ、８　圧力センサ故障診断回路、９，１０　アナログフィルタ回路、１１，１２，１３　デジタルフィルタ回路、Ｐｉｎｊ　燃料噴射圧力センサ、Ｐｔｃｏｕｔ　ターボ出口排気圧力センサ、Ｐｍａｐ　インテークマニホールド圧力センサ、Ｐａｉｒ　ターボ上流空気圧力センサ、Ｐｔｈ　スロットル上流圧力センサ 1 engine, 2 intake manifold, 3 ECU, 4 microcomputer, 5 engine control processing circuit, 6 throttle valve, 7 throttle valve opening sensor, 8 pressure sensor failure diagnosis circuit, 9, 10 analog filter circuit, 11, 12, 13 Digital filter circuit, Pinj fuel injection pressure sensor, Ptcout turbo outlet exhaust pressure sensor, Pmap intake manifold pressure sensor, Pair turbo upstream air pressure sensor, Pth throttle upstream pressure sensor

Claims (7)

  1. 　火花点火式のエンジン制御に用いられるエンジンの吸気系または排気系に備えた圧力センサの応答性劣化診断方法であって、
    　前記エンジンの作動時におけるピストンの往復動に伴う吸気または排気によって前記エンジンの吸気系または排気系に生じる圧力脈動振幅である圧力センサ信号情報を計測して指標値化した計測指標値を、正常時の前記圧力センサ信号情報から指標値化した正常指標値と比較することで前記エンジンの制御に用いられる圧力センサに生じた応答性の劣化を診断することを特徴とするエンジン制御に用いられる圧力センサの応答性診断方法。     It is a method for diagnosing responsiveness deterioration of a pressure sensor provided in the intake system or exhaust system of an engine used for spark ignition type engine control.
    The measurement index value obtained by measuring the pressure sensor signal information, which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the engine by the intake or exhaust accompanying the reciprocating movement of the piston when the engine is operating, is used as an index value in the normal state. A pressure sensor used for engine control, which is characterized in diagnosing deterioration of responsiveness caused in the pressure sensor used for controlling the engine by comparing with a normal index value converted into an index value from the pressure sensor signal information of the above. Responsiveness diagnostic method.
  2. 　前記計測したエンジンの吸気系または排気系に生じる圧力脈動振幅である圧力センサ信号情報をエンジン制御装置内部に配置されたアナログフィルタ低域通過フィルタ回路により処理して指標値化することを特徴とする請求項１記載のエンジン制御に用いられる圧力センサの応答性診断方法。 The pressure sensor signal information, which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the engine, is processed by an analog filter low-pass filter circuit arranged inside the engine control device and converted into an index value. The method for diagnosing the responsiveness of a pressure sensor used for engine control according to claim 1.
  3. 　前記計測したエンジンの吸気系または排気系に生じる圧力脈動振幅である圧力センサ信号情報をエンジン制御装置内部に配置されたデジタル低域通過フィルタ回路により処理して指標値化することを特徴とする請求項１または２記載のエンジン制御に用いられる圧力センサの応答性診断方法。 A claim characterized in that the pressure sensor signal information, which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the measured engine, is processed by a digital low-pass filter circuit arranged inside the engine control device and converted into an index value. Item 3. The method for diagnosing the responsiveness of a pressure sensor used for engine control according to Item 1 or 2.
  4. 　前記デジタル低域通過フィルタ回路により処理が、高周波数振動を有する圧力センサ信号情報から、帯域通過フィルタと絶対値化処理、加重平均処理から圧力センサが検出した高周波数帯の圧力脈動振幅を指標化し、この指標値から圧力センサの応答性を数値化して故障の有無を判断することを特徴とする請求項３記載のエンジン制御に用いられる圧力センサの応答性診断方法。 The processing by the digital low-pass filter circuit indexes the pressure pulsation amplitude in the high-frequency band detected by the pressure sensor from the band-passing filter, absolute value processing, and weighted averaging processing from the pressure sensor signal information having high-frequency vibration. The method for diagnosing the responsiveness of a pressure sensor used for engine control according to claim 3, wherein the responsiveness of the pressure sensor is quantified from this index value to determine the presence or absence of a failure.
  5. 　前記得られた指標値をエンジン運転中において最大値を更新し、この最大値を評価することで、特定の運転条件だけではなく、様々な運転条件を１つの指標で応答性故障の判定を行うことを特徴とする請求項１，２，３または４記載のエンジン制御に用いられる圧力センサの応答性診断方法。 By updating the maximum value of the obtained index value during engine operation and evaluating this maximum value, it is possible to determine not only specific operating conditions but also various operating conditions with one index for responsive failure. The method for diagnosing the responsiveness of a pressure sensor used for engine control according to claim 1, 2, 3 or 4.
  6. 　前記エンジンの吸気系または排気系に備えた圧力センサが定常運転において圧力脈動が現れるセンサの場合は、加速条件などを経験することなく前記指標値から応答性故障の判定を行うことを特徴とする請求項１，２，３または４記載のエンジン制御に用いられる圧力センサの応答性診断方法。 When the pressure sensor provided in the intake system or the exhaust system of the engine is a sensor in which pressure pulsation appears in steady operation, it is characterized in that a responsive failure is determined from the index value without experiencing acceleration conditions or the like. The method for diagnosing the responsiveness of a pressure sensor used for engine control according to claim 1, 2, 3 or 4.
  7. 　前記計測したエンジンの吸気系または排気系に生じる圧力脈動振幅である圧力センサ信号情報をエンジン制御装置内部に配置されたエンジン制御に不要な高域周波数帯を除去する低域通過フィルタ処理により、前記圧力センサ信号情報をエンジン制御に用いる圧力情報として用いることを特徴とする請求項１，２，３，４，５または６記載のエンジン制御に用いられる圧力センサの応答性診断方法。 The pressure sensor signal information, which is the pressure pulsation amplitude generated in the intake system or the exhaust system of the measured engine, is subjected to the low frequency pass filter processing for removing the high frequency band unnecessary for engine control arranged inside the engine control device. The method for diagnosing the responsiveness of a pressure sensor used for engine control according to claim 1, 2, 3, 4, 5 or 6, wherein the pressure sensor signal information is used as pressure information used for engine control.
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JPH01151754A (en) * 1987-12-07 1989-06-14 Aisan Ind Co Ltd Intake air pipe pressure measuring device

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JP3260404B2 (en) 1991-10-18 2002-02-25 川鉄鉱業株式会社 Heat resistant fibrous chromatic pigment
US7204134B2 (en) 2003-03-03 2007-04-17 Noritaka Matsuo Engine suction air flow rate measuring device

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JPH01151754A (en) * 1987-12-07 1989-06-14 Aisan Ind Co Ltd Intake air pipe pressure measuring device

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