JPH07116962B2 - Air-fuel ratio controller for internal combustion engine - Google Patents
Air-fuel ratio controller for internal combustion engineInfo
- Publication number
- JPH07116962B2 JPH07116962B2 JP61056894A JP5689486A JPH07116962B2 JP H07116962 B2 JPH07116962 B2 JP H07116962B2 JP 61056894 A JP61056894 A JP 61056894A JP 5689486 A JP5689486 A JP 5689486A JP H07116962 B2 JPH07116962 B2 JP H07116962B2
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- Japan
- Prior art keywords
- value
- engine
- operating state
- amount
- fuel injection
- Prior art date
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- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は内燃機関の空燃比制御装置に関し、特に、噴射
する燃料が実際に燃焼室内に供給される時の吸入空気量
を予測して、予測値に見合う燃料量を噴射することがで
きる内燃機関の空燃比制御装置に関する。Description: TECHNICAL FIELD The present invention relates to an air-fuel ratio control device for an internal combustion engine, and in particular, predicts the intake air amount when the fuel to be injected is actually supplied to the combustion chamber, The present invention relates to an air-fuel ratio control device for an internal combustion engine that can inject a fuel amount that matches a predicted value.
機関の運転状態パラメータ（例えば吸気管内圧力や回転
速度）を検出し、検出したパラメータに応じて噴射すべ
き燃料量を演算し、その演算値に応じて燃料噴射を行う
機関においては、運転状態パラメータ検出時と、演算値
に基づく燃料が実際に燃焼室に導かれる時点との時間的
なずれにより、機関が真に要求する燃料量を供給できな
い場合がある。An engine operating condition parameter (for example, intake pipe pressure or rotational speed) is detected, the amount of fuel to be injected is calculated according to the detected parameter, and fuel injection is performed according to the calculated value. In some cases, the amount of fuel that the engine truly requires cannot be supplied due to the time lag between the time of detection and the time when fuel based on the calculated value is actually introduced into the combustion chamber.
例えば第４図に示す如く、燃料噴射前の所定クランク角
度位置Ａでその時の吸気管内圧力と回転速度とから燃料
噴射パルス幅を演算した場合は、このパルス幅でインジ
ェクタをＢの期間駆動して燃料噴射を行う。吸気弁がＣ
の期間開き、これにより燃料が燃焼室に供給される。こ
の場合、実際に燃料が燃焼室内に入るのはＤの位置近傍
であり、この時に燃焼室内に導入される空気量は、噴射
直前に検出した吸気管内圧と回転速度とから演算した空
気量とは異なるものである。For example, as shown in FIG. 4, when the fuel injection pulse width is calculated from the intake pipe internal pressure and the rotational speed at the predetermined crank angle position A before fuel injection, the injector is driven with this pulse width for the period B. Inject fuel. Intake valve is C
During which the fuel is supplied to the combustion chamber. In this case, the fuel actually enters the combustion chamber near the position D, and the amount of air introduced into the combustion chamber at this time is the amount of air calculated from the intake pipe internal pressure detected immediately before injection and the rotation speed. Is different.
このように噴射量の演算に用いる吸入空気量の検出値
（PM値）と実際に燃焼室に入る空気量とに差があると、
特に機関が過渡運転状態にある場合、燃料量に著しい過
不足が生じてしまう。従来は、この過不足を補償するた
めにスロットル弁の開度信号等に応じて燃料の増量、減
量制御を行っていたが、十分に補償することは困難であ
り、運転特性の悪化及びエミッション上の悪化を招いて
いた。In this way, if there is a difference between the detected value (PM value) of the intake air amount used to calculate the injection amount and the air amount that actually enters the combustion chamber,
In particular, when the engine is in a transient operation state, there will be a significant excess or deficiency in the fuel amount. In the past, in order to compensate for this excess or deficiency, fuel quantity increase / decrease control was performed according to the throttle valve opening signal, etc., but it is difficult to make sufficient compensation, resulting in deterioration of operating characteristics and emission. Had been aggravated.
そこで、燃料噴射前に次回の基本噴射量演算に用いるPM
値（圧力センサによる吸気管内圧またはエアフローメー
タ等による吸入空気量値）、即ち、今回の噴射時に最適
なPM値を現在、及び過去の所定クランク角毎の燃料噴射
量計算タイミング時のPM値を用いて近似計算により予測
し、近似計算による予測PM値（PM CAL）と機関の回転速
度とから燃料噴射量を計算し、この計算値により燃料噴
射を実行する方法を本発明者らは既に提案した（特願昭
59−22962号公報）。この方法によれば、過渡時の燃料
噴射量をより機関の要求噴射量に近づけることができ、
過渡運転時のドライバビリティ、エミッションの向上を
図れた。Therefore, PM used for the next basic injection amount calculation before fuel injection
Value (intake pipe pressure by pressure sensor or intake air amount value by air flow meter, etc.), that is, the optimum PM value at the time of this injection, and the PM value at the time of fuel injection amount calculation timing at each predetermined crank angle in the past The present inventors have already proposed a method of predicting the fuel injection amount by using the approximate calculation, calculating the fuel injection amount from the predicted PM value (PM CAL) by the approximate calculation, and the rotation speed of the engine, and executing the fuel injection based on the calculated value. Yes
59-22962). According to this method, the fuel injection amount at the time of transition can be brought closer to the required injection amount of the engine,
We were able to improve drivability and emissions during transient operation.
しかしながら、前述の方法によりPM CALの予測計算を機
関の定常運転状態で行うと、定常運転状態でも前記PM値
は機関のクランク角度に応じて脈動しており、前述の方
法では噴射時のPM CALの計算に、前記燃料噴射量計算タ
イミングにおける時間周期でA/D変換されたPM値の最新
のものを使用しているために、かえって予測されたPM C
AL値が変動し、燃料噴射量が変動してサージングの発生
を促し、定常状態でのドライバビリティの悪化やエミッ
ションの悪化を招くという問題点があった。However, when the PM CAL prediction calculation is performed in the steady operation state of the engine by the above-mentioned method, the PM value pulsates according to the crank angle of the engine even in the steady operation state. Since the latest PM value A / D converted in the time period at the fuel injection amount calculation timing is used for the calculation of
There is a problem that the AL value fluctuates, the fuel injection amount fluctuates, and the occurrence of surging is promoted, which leads to deterioration of drivability in a steady state and deterioration of emission.
即ち、第５図に示すように、４気筒内燃機関では、定常
運転状態におけるPM波形は符号イで示すようにほぼ180
゜クランク角（CA）周期で変動しており、一方、従来の
方法ではPM値のA/D変換が所定の時間周期で行われてい
るため、符号ロで示すA/D変換後のPM波形がA/D変換前の
PM波形と同調せず、A/D変換後のPM波形にはリップルが
生じている。この結果、燃料噴射量計算に用いるPM値は
燃料噴射量計算タイミングＴにおけるPM値のA/D変換値
であるので、このリップルの影響を受け、符号ハで示す
ように一定値とはならない。That is, as shown in FIG. 5, in the four-cylinder internal combustion engine, the PM waveform in the steady operation state is almost 180
° PM waveform after A / D conversion indicated by symbol B because the A / D conversion of the PM value is performed in a predetermined time cycle in the conventional method while it fluctuates in the crank angle (CA) cycle. Is before A / D conversion
The PM waveform is not tuned and ripples are generated in the PM waveform after A / D conversion. As a result, since the PM value used for the fuel injection amount calculation is the A / D converted value of the PM value at the fuel injection amount calculation timing T, it is affected by this ripple and does not become a constant value as indicated by symbol C.
そして、前述の方法によるPM値の予測計算を機関の定常
運転状態で行うと、今回の燃料噴射量計算タイミングに
おけるPM値をPM0（で示す）、前回の同PM値をPM1（
で示す）、前々回の同PM値をPM2（で示す）とした時
に、次回の噴射時（噴射量計算タイミングから360゜CA2
0後）の予測値PM CALは次式、 PM CAL＝2.5PM0−2PM1＋0.5PM2 にて計算されることになり、で示す波形となる（以後
同様の計算によりPM CALは破線ニで示す波形となる）。
このように、機関の定常運転状態にて前述の方法を使用
すると、A/D変換後のPM値の変動が助長されて、PM CAL
の変動が大きくなって燃料噴射量が変動し、サージング
の発生が促進されてドライバビリティやエミッションが
悪化するのである。Then, when the PM value prediction calculation by the above-described method is performed in the steady operation state of the engine, the PM value at this fuel injection amount calculation timing is PM0 (indicated by), and the previous PM value is PM1 (indicated by PM1 (
When the same PM value of the previous two times is set to PM2 (indicated by), the next injection (360 ° CA2 from the injection amount calculation timing)
The predicted value PM CAL of (after 0) will be calculated by the following formula, PM CAL = 2.5PM0-2PM1 + 0.5PM2, and the waveform becomes as shown by (the subsequent calculation shows PM CAL as the waveform shown by the broken line D). Become).
As described above, when the above-mentioned method is used in the steady operation state of the engine, the PM value variation after A / D conversion is promoted, and the PM CAL
Is increased, the fuel injection amount is changed, the occurrence of surging is promoted, and drivability and emission are deteriorated.
すなわち、定常時のPM値の変動は行程（クランク角）同
期であり、例えば、第６図（ａ）に示すように４気筒な
ら180゜CA周期で行われる。一方、燃料噴射TAUの計算も
第６図（ａ）に示すようにクランク角周期（一斉噴射な
ら360゜CA周期）である。そこで、取り込むPM値はA/D変
換が無限に早ければほぼ同じ値になるはずである。That is, the fluctuation of the PM value in the steady state is in synchronization with the stroke (crank angle), and for example, as shown in FIG. On the other hand, the calculation of the fuel injection TAU is also the crank angle cycle (360 ° CA cycle for simultaneous injection) as shown in FIG. 6 (a). Therefore, the PM values to be captured should be almost the same if A / D conversion is infinitely fast.
ところが、実際のA/D変換は数ms周期であり、機関回転
数が6000rpm時の180゜CA時間は5msである。従って、第
６図（ｂ）に示すように、燃料噴射量の予測値TAUcalを
演算する時のΔPMも、定常時は本当はPMb−PMa≒０であ
るべきであるが、燃料噴射量の予測値TAUcalを演算する
ルーチンの待ち時間、PM波形とA/D変換タイミングの位
相ずれ等により、実際はPM−PMとなり、ΔPMは定常
といえども大きな値になり、過渡時の判定値を大きな値
にする必要があった。However, the actual A / D conversion has a cycle of several ms, and the 180 ° CA time when the engine speed is 6000 rpm is 5 ms. Therefore, as shown in FIG. 6 (b), ΔPM when calculating the predicted value TAUcal of the fuel injection amount should also be PMb−PMa≈0 in the steady state, but the predicted value of the fuel injection amount Due to the waiting time of the routine that calculates TAUcal, the phase shift between the PM waveform and the A / D conversion timing, etc., it actually becomes PM-PM, and ΔPM becomes a large value even though it is steady, and the judgment value at the time of transition is made a large value. There was a need.
本発明の目的は、機関の過渡運転状態時には本発明者ら
が既に提案した方法による噴射量制御の利点を生かした
ドライバビリティ、エミッションの向上を図り、定常運
転時にはPM CAL値の変動に起因する噴射量の変動を排除
し、ドライバビリティの向上、エミッションの悪化を防
止することができる優れた内燃機関の空燃比制御装置を
提供することである。また、本発明の他の目的は、定常
運転状態と過渡運転状態との判定における判定レベルを
大きくとらなくても誤判定の恐れがなく、過渡と定常と
の変化のタイミングを的確にとらえて応答性を良くし、
定常時及び過渡時初期のドライバビティ及びエミッショ
ンを向上させることができる内燃機関の空燃比制御装置
を提供することである。An object of the present invention is to improve drivability and emission by making use of the advantages of the injection amount control by the method already proposed by the present inventors when the engine is in a transient operation state, and due to a change in PM CAL value during steady operation. It is an object of the present invention to provide an excellent air-fuel ratio control device for an internal combustion engine that can eliminate fluctuations in the injection amount, improve drivability, and prevent deterioration of emissions. Further, another object of the present invention is to provide a response by accurately grasping the timing of change between transient and steady without causing a risk of erroneous determination even if the determination level in the determination of the steady operating state and the transient operating state is not large. To improve sex,
It is an object of the present invention to provide an air-fuel ratio control device for an internal combustion engine, which is capable of improving the driver's vitiy and the emission at the constant time and at the initial stage of the transient time.
すなわち、本発明の目的は、ΔPMとして入力値同士の差
をとるのではなく、PM0なる今回の入力値と、PMAVなる
過渡判別時には予測値、定常判別時には予測値を十分な
ました値とを比較することにより、定常状態から過渡状
態への変化の判定時に、その応答性を向上させることに
ある。That is, the object of the present invention is not to take the difference between the input values as ΔPM, but to set the current input value of PM0, the predicted value at the transient judgment of PMAV, and the sufficient value at the steady judgment. By comparing, it is to improve the responsiveness when determining the change from the steady state to the transient state.
前記目的を達成する本発明の内燃機関の空燃比制御装置
は、第１図に示すように、機関の吸入空気量の検出手段
により、時間周期でA/D変換された吸入空気量の検出値
を、所定クランク角毎の燃料噴射量演算タイミング時に
取り込み、記憶手段によって所定回数分記憶し、記憶さ
れた少なくとも前回の検出値、及び最新の検出値により
噴射時の吸入空気量を予測演算手段によって予測演算
し、この予測演算による予測値と機関の回転速度とか
ら、噴射量演算手段が次回の燃料噴射量を演算して燃料
噴射を実行する内燃機関の空燃比制御装置において、機
関の運転状態が過渡運転状態か定常運転状態かを、機関
の運転状態の変化量によって判別する過渡・定常判別手
段と、機関の過渡運転状態の時に、前記演算された演算
値をそのまま予測値とし、機関の定常運転状態の時に、
前記演算値を平均化処理して予測値とする予測値設定手
段と、前記予測値を用いて前記機関の運転状態の変化量
を演算する運転状態変化量手段とを備えていることを特
徴としている。The air-fuel ratio control apparatus for an internal combustion engine according to the present invention which achieves the above object, as shown in FIG. 1, is a detection value of the intake air amount A / D converted in a time cycle by the intake air amount detection means of the engine. Is taken in at the fuel injection amount calculation timing for each predetermined crank angle, and is stored a predetermined number of times by the storage means, and the intake air amount at the time of injection is predicted by the prediction calculation means based on the stored at least the previous detection value and the latest detection value. In the air-fuel ratio control device for the internal combustion engine, the injection amount calculation means calculates the next fuel injection amount from the prediction value obtained by the prediction calculation and the engine rotation speed to execute the fuel injection. Is a transient operating state or a steady operating state, the transient / steady state determining means for determining the change amount of the operating state of the engine, and when the engine is in the transient operating state, the calculated value is directly used as the predicted value. At the time of the steady operating state of the engine,
A predictive value setting means for averaging the calculated values to obtain a predicted value, and an operating state change amount means for computing the amount of change in the operating state of the engine using the predicted value are provided. There is.
本発明の内燃機関の空燃比制御装置によれば、機関の過
渡運転状態においては機関の吸入空気量の最新の検出値
及び少なくとも前回の検出値の値をもとに、次回の噴射
時の吸入空気量の予測演算値が求められてこれが予測値
され、定常運転状態においては前記演算値がなまし処理
されたなまし値が予測値とされ、その予測値に基づいて
演算された燃料量が次回の燃料供給時期に供給される。According to the air-fuel ratio control device for an internal combustion engine of the present invention, in the transient operation state of the engine, the intake air at the next injection is based on the latest detected value of the intake air amount of the engine and at least the value of the previous detected value. A predicted calculated value of the air amount is obtained and this is a predicted value, and in a steady operation state, the smoothed value obtained by smoothing the calculated value is set as the predicted value, and the fuel amount calculated based on the predicted value is calculated. It will be supplied at the next fuel supply time.
以下図面を用いて本発明の実施例を詳細に説明する。Embodiments of the present invention will be described in detail below with reference to the drawings.
第２図には本発明の内燃機関の空燃比制御装置の一実施
例を備えた電子制御燃料噴射式内燃機関が概略的に示さ
れている。この図において、機関（エンジン）１の吸気
通路２には吸入空気量の検出手段として吸気管内圧を検
出する圧力センサ３が設けられている。この圧力センサ
３には例えば圧力に比例する歪により伝播位相遅れを生
じる表面弾性波を用いたSAW式センサ等が使用され、圧
力信号がこの位相遅れ時間に反比例する発振周波数によ
って取り出される。この圧力信号は制御回路10のマルチ
プレクサ内蔵A/D変換器101に供給されている。ディスト
リビュータ４には、その軸が例えば360゜CA毎に基準位
置検出用パルス信号を発生するクランク角センサ５及び
30゜CA毎に基準位置検出用パルス信号を発生するクラン
ク各センサ６が設けられている。これらクランク角セン
サ5,6のパルス信号は制御回路10の入出力インタフェー
ス102に供給され、このうちクランク角センサ６の出力
はCPU103の割込端子に供給される。FIG. 2 schematically shows an electronically controlled fuel injection type internal combustion engine equipped with an embodiment of the air-fuel ratio control system for an internal combustion engine of the present invention. In this figure, a pressure sensor 3 for detecting the intake pipe internal pressure is provided in an intake passage 2 of an engine 1 as a means for detecting the intake air amount. As the pressure sensor 3, for example, a SAW sensor using a surface acoustic wave that causes a propagation phase delay due to strain proportional to pressure is used, and a pressure signal is extracted at an oscillation frequency that is inversely proportional to the phase delay time. This pressure signal is supplied to the A / D converter 101 with a built-in multiplexer in the control circuit 10. The distributor 4 has a crank angle sensor 5 whose axis generates a reference position detecting pulse signal at every 360 ° CA, and
Each crank sensor 6 for generating a reference position detection pulse signal at every 30 ° CA is provided. The pulse signals of the crank angle sensors 5 and 6 are supplied to the input / output interface 102 of the control circuit 10, and the output of the crank angle sensor 6 is supplied to the interrupt terminal of the CPU 103.
さらに、吸気通路２に各気筒毎に燃料供給系から加圧燃
料を吸気ポートへ供給するための燃料噴射弁７が設けら
れている。Further, a fuel injection valve 7 is provided in the intake passage 2 for each cylinder to supply pressurized fuel from the fuel supply system to the intake port.
また、エンジン１のシリンダブロックの冷却水通路Ｗに
は、冷却水の温度を検出するための水温センサ11が設け
られている。水温センサ11は冷却水の温度THWに応じた
アナログ電圧の電気信号を発生する。この出力もA/D変
換器101に供給されている。A water temperature sensor 11 for detecting the temperature of the cooling water is provided in the cooling water passage W of the cylinder block of the engine 1. The water temperature sensor 11 generates an electric signal of analog voltage according to the temperature THW of the cooling water. This output is also supplied to the A / D converter 101.
制御回路10は、例えばマイクロコンピュータとして構成
され、前述のA/D変換器101,入出力インタフェース102,C
PU103の他にROM104,RAM105,イグニッションスイッチオ
フ後も情報の保持を行うバックアップRAM109等が設けら
れており、これらはパス110で接続されている。The control circuit 10 is configured as, for example, a microcomputer, the A / D converter 101, the input / output interface 102, C described above.
In addition to the PU 103, a ROM 104, a RAM 105, a backup RAM 109 that retains information even after the ignition switch is turned off, and the like are provided, and these are connected by a path 110.
この制御回路10において、ダウンカウンタ106,フリップ
フロップ107,及び駆動回路108は燃料噴射弁７を制御す
るためのものである。即ち、燃料噴射量TAUが演算され
ると、燃料噴射量TAUがダウンカウンタ106にプリセット
されると共にフリップフロップ107もセットされる。こ
の結果、駆動回路108が燃料噴射弁７の付勢を開始す
る。他方、ダウンカウンタ106がクロック信号（図示せ
ず）を計数して最後にそのキャリアウト端子が“1"レベ
ルになった時に、フリップフロップ107がリセットされ
て駆動回路108は燃料噴射弁７の付勢を停止する。つま
り、前述の燃料噴射量TAUだけ燃料噴射弁７は付勢さ
れ、したがって、燃料噴射量TAUに応じた量の燃料がエ
ンジン１の燃焼室に送り込まれることになる。In the control circuit 10, the down counter 106, the flip-flop 107, and the drive circuit 108 are for controlling the fuel injection valve 7. That is, when the fuel injection amount TAU is calculated, the fuel injection amount TAU is preset in the down counter 106 and the flip-flop 107 is also set. As a result, the drive circuit 108 starts energizing the fuel injection valve 7. On the other hand, when the down counter 106 counts a clock signal (not shown) and finally its carry-out terminal becomes the "1" level, the flip-flop 107 is reset and the drive circuit 108 is provided with the fuel injection valve 7. Stop the momentum. That is, the fuel injection valve 7 is biased by the above-mentioned fuel injection amount TAU, and therefore, the amount of fuel corresponding to the fuel injection amount TAU is sent to the combustion chamber of the engine 1.
制御回路10にはその他に吸気温センサ（図示せず）、ス
ロットル弁12の開いたことを検出するスロットルスイッ
チ13、スロットル弁12の開度センサ14、酸素濃度センサ
９、トランスミッション16からのスピードメータケーブ
ルに設けられた車速センサ17等からの検出信号が送り込
まれる。また、制御回路10からはディストリビュータ４
に内蔵されるイグナイタに点火信号が出力され、これに
よって点火プラグ15の通電制御が行われるが、これらは
本発明と直接関係がないため説明を省略する。The control circuit 10 additionally includes an intake air temperature sensor (not shown), a throttle switch 13 for detecting the opening of the throttle valve 12, an opening sensor 14 for the throttle valve 12, an oxygen concentration sensor 9, and a speedometer from the transmission 16. A detection signal from the vehicle speed sensor 17 or the like provided on the cable is sent. In addition, from the control circuit 10 to the distributor 4
An ignition signal is output to an igniter built in the control unit, and the energization control of the ignition plug 15 is performed by the ignition signal. However, since these are not directly related to the present invention, description thereof will be omitted.
圧力センサ３の検出信号は、所定時間毎に実行されるA/
D変換ルーチンにより２進信号に変換され、吸気管圧力P
M0を表すデータとしてそのまま、あるいは本実施例のよ
うになまし処理された後にその都度RAM105に格納され
る。ディストリビュータ４内のクランク角センサ６から
のクランク角30゜毎の信号は、入出力インタフェース10
2を介して制御回路10内に取り込まれ、回転速度Ne及び
燃料噴射量TAUを演算する30゜CA割込信号となる。The detection signal of the pressure sensor 3 is A /
It is converted into a binary signal by the D conversion routine, and the intake pipe pressure P
The data is stored as it is as the data representing M0, or is stored in the RAM 105 each time after being subjected to the smoothing processing as in the present embodiment. The signal from the crank angle sensor 6 in the distributor 4 for every 30 ° of crank angle is input / output interface 10
It is taken into the control circuit 10 via 2 and becomes a 30 ° CA interrupt signal for calculating the rotation speed Ne and the fuel injection amount TAU.
次に第３図のフローチャートを用いて前述の制御回路10
の動作を説明する。Next, referring to the flowchart of FIG.
The operation of will be described.
第３図は本発明の内燃機関の空燃比制御装置の動作手順
で示しており、この手順は１回転１回噴射の機関の場合
１回転毎に行われるものである。ステップ301では圧力
センサ３からの最新のPM検出値のA/D変換後の値PMがPM0
としてRAM105に記憶される。この時、A/D変換後のPM値
にある程度のなまし処理を行っても良い。FIG. 3 shows an operation procedure of the air-fuel ratio control apparatus for an internal combustion engine of the present invention, and this procedure is performed every one rotation in the case of an engine having one injection per one rotation. In step 301, the value PM after A / D conversion of the latest PM detection value from the pressure sensor 3 is PM0.
Is stored in the RAM 105 as. At this time, the PM value after A / D conversion may be subjected to some degree of smoothing processing.
ステップ302では機関が過渡運転状態か定常運転状態か
を判定するために、吸入空気量の変化分ΔPMが求められ
る。このΔPMは今回の検出値PM0と前回（機関１回転
前）の予測値PM AVとの差であるが、前回が機関の過渡
運転状態の場合は、PM AVに前回のPM0であるPM1が入っ
ており、前回が定常運転状態の場合は、PM AVに予測演
算値PM CALがなまし処理された値が入っている。In step 302, the change amount ΔPM of the intake air amount is obtained in order to determine whether the engine is in a transient operating state or a steady operating state. This ΔPM is the difference between the detected value PM0 of this time and the predicted value PM AV of the previous time (before one revolution of the engine). If the previous time was the transient operation state of the engine, PM1 which is the previous PM0 is entered in PM AV. Therefore, if the previous time was in the steady operation state, PM AV contains the value obtained by smoothing the predicted calculation value PM CAL.
ステップ303ではRAM105から最新のPM値であるPM0、前回
の割込時のPM値であるPM1、及び前々回の割込時のPM値
であるPM2が読み出される。次いでステップ304にて今回
算出する燃料噴射量に従って噴射される燃料が実際に燃
焼室に到達する時点における吸入空気量の予測演算値PM
CALが演算される。In step 303, the latest PM value PM0, the PM value PM1 at the last interrupt, and the PM value PM2 at the two-previous interrupt are read from the RAM 105. Next, at step 304, the predicted calculated value PM of the intake air amount when the fuel injected according to the fuel injection amount calculated this time actually reaches the combustion chamber
CAL is calculated.
この予測演算に用いられる多項式は、現在までのデータ
から未来の値を予測するのに一般に使用されるマクロー
リン展開を用いた式であり、PM CALは次式で表される。The polynomial used for this prediction calculation is an expression using the Maclaurin expansion that is generally used to predict a future value from the data up to the present, and PM CAL is represented by the following expression.
PM CAL＝2.5PM0−2.0PM1＋0.5PM2 この後ステップ305に進み、ここで次回の割込時の予測
値演算に備えるため、PM1の値がPM2に、PM0の値がPM1に
それぞれ移動され、これらがRAM105に記憶される。PM CAL = 2.5PM0-2.0PM1 + 0.5PM2 After that, proceed to step 305, where the value of PM1 is moved to PM2 and the value of PM0 is moved to PM1 to prepare for the calculation of the predicted value at the next interrupt. Is stored in the RAM 105.
ステップ306では前回の噴射量計算時が過渡運転状態で
あったか、定常運転状態であったかが過渡判定フラグXT
RANによって判別される。このフラグXTRANは開始始動後
のイニシャルルーチンにおいて“0"にされているもので
あり、過渡運転状態の時に“1"にされ、定常運転状態の
時に“0"に戻されるものである。従って、ステップ306
でXTRAN＝“1"（YES）であれば、機関１回転前が過渡運
転状態であり、ステップ306でXTRAN＝“0"（NO）であれ
ば、機関１回転前が定常運転状態である。そして、１回
転前が過渡運転状態（YES）の場合はステップ307に進ん
で、｜ΔPM|と判定レベルPMLV1との比較により今回の過
渡・定常を判別し、１回転前が定常運転状態の場合（N
O）はステップ308に進んで｜ΔPM|判定レベルPMLV1との
比較により今回の過渡・定常を判別する。但し、ここで
PMLV1＞PMLV2である。In step 306, it is determined whether the previous injection amount calculation was in the transient operation state or in the steady operation state.
Determined by RAN. This flag XTRAN is set to "0" in the initial routine after starting and starting, is set to "1" in the transient operation state, and is returned to "0" in the steady operation state. Therefore, step 306
If XTRAN = "1" (YES), the engine 1 revolution is in the transient operation state, and if XTRAN = "0" (NO) in step 306, the engine 1 revolution is the steady operation state. If one revolution before is in the transient operation state (YES), the routine proceeds to step 307, where | ΔPM | and the determination level PMLV1 are compared to determine the present transient / steady state, and one revolution before is in the steady operation state. (N
O) advances to step 308 to determine the present transient / steady state by comparing with | ΔPM | determination level PMLV1. However, here
PMLV1> PMLV2.
ステップ307で｜ΔPM|＞PMLV1（YES）またはステップ30
8で｜ΔPM|＞PMLV2（YES）となった時は、過渡運転状態
と判定されてステップ309に進んでXTRAN＝“1"にされ、
続くステップ311にて予測値PM AVにステップ304で求め
られた演算値PM CALが入る。In step 307 ｜ ΔPM | ＞ PMLV1 (YES) or step 30
When | ΔPM |> PMLV2 (YES) in 8 is determined to be a transient operating state, the process proceeds to step 309 and XTRAN is set to “1”,
In the following step 311, the calculated value PM CAL obtained in step 304 is entered in the predicted value PM AV.
一方、ステップ307で｜ΔPM|＜PMLV1（NO）またはステ
ップ308で｜ΔPM|＜PMLV2（NO）となった時は、定常状
態と判定されてステップ310に進んでXTRAN＝“0"にされ
た後にステップ312に進み、ここでPM AVに演算値PM CAL
が次式により平均化処理としてのなまし処理されてい
る。On the other hand, when | ΔPM | <PMLV1 (NO) in step 307 or | ΔPM | <PMLV2 (NO) in step 308, it is determined that the steady state is reached, and the routine proceeds to step 310, where XTRAN = "0" is set. After that, proceed to step 312, where the calculated value PM CAL is added to PM AV.
Is annealed by the following equation.
PM AV＝1/16（15PM AV＋PM CAL） ……（ａ） （ａ）式は前回の予測値PM AVを15倍し、その値に今回
の演算値PM CALを加えて16で割ってなます処理を示して
おり、前回の予測値PM AVに15の重み、今回の演算値PM
CALに１の重みをつけてなまし処理を行っているもので
ある。このなまし回数を増やす程PM AVの変動が小さく
なり、定常運転状態での燃料噴射量のばらつきによるド
ライバビリティ、エミッションの悪化を解消することが
できる。PM AV = 1/16 (15PM AV + PM CAL) (a) (a) is calculated by multiplying the previous predicted value PM AV by 15 and adding this calculated value PM CAL to divide by 16. Processing shows that the previous predicted value PM AV is weighted by 15 and this calculated value PM is
The CAL is given a weight of 1 to perform the annealing process. As the number of times of this smoothing is increased, the fluctuation of PM AV becomes smaller, and it is possible to eliminate the deterioration of drivability and emission due to the variation of the fuel injection amount in the steady operation state.
この後ステップ313において予測値PM AVとこの時の機関
の回転速度Neとから基本燃料噴射量TAUPが基本噴射パル
ス幅TPとして周知の方法、例えばTP＝ｇ（Ne,PM AV）の
テーブルを用いる方法等によって求められる。TPはこの
後、冷却水温センサ11、吸気温センサ（図示せず）、ス
ロットルスイッチ13、開度センサ14、酸素濃度センサ９
等からの検出信号及びバッテリ電圧等による補正によっ
て最終的な燃料噴射量TAUとなり、RAM105に一時的に格
納され、以後噴射時期になった時にCPU103により燃料が
噴射される。Thereafter, in step 313, a method is used in which the basic fuel injection amount TAUP is known as the basic injection pulse width TP from the predicted value PM AV and the engine speed Ne at this time, for example, a table of TP = g (Ne, PM AV) is used. It is calculated by the method. After that, TP is a cooling water temperature sensor 11, an intake air temperature sensor (not shown), a throttle switch 13, an opening sensor 14, and an oxygen concentration sensor 9.
The final fuel injection amount TAU becomes the final fuel injection amount TAU by the correction of the detection signal from the battery, the battery voltage, etc., is temporarily stored in the RAM 105, and the fuel is injected by the CPU 103 at the injection timing thereafter.
この後、ステップ314にて今回が定常運転状態か過渡運
転状態かがフラグXTRANによって判別され、定常運転状
態の時（NO）はそのままリターンするが、過渡運転状態
の時（YES）はステップ315にはPM AVに次回のΔPMの演
算のために、今回のPM値であるPM0を入れてからリター
ンする。After this, in step 314, it is determined whether the present time is the steady operation state or the transient operation state by the flag XTRAN. When the steady operation state (NO), the routine returns, but in the transient operation state (YES), the step 315 is performed. Returns the value after inputting PM0, which is the current PM value, to PM AV for the next calculation of ΔPM.
ここで、前回まで定常運転状態であった場合を考える
と、PM AVはPMの予測値の平均的な値を保持しており、
今回も定常運転状態であるならば最新のPMつまりPM0はP
M AVに近い値となる。従って、従来の（PM0−PM1）によ
りΔPMを算出する方法に比べると、PM AVはPM1より安定
しているので、定常運転状態から過渡運転状態への移行
の判定レベルPMLV2を小さくすることが可能になる。こ
の結果、過渡運転状態を検出するタイミングが従来より
早くなり、過渡運転状態の初期においてもPMの予測値PM
AVにより機関の要求に近い燃料噴射量の算出が可能に
なり、ドライバビリティ、エミッションの向上を図るこ
とができる。Here, considering the case of steady operation until the last time, PM AV holds the average value of the predicted value of PM,
If the steady operation state is again this time, the latest PM, that is, PM0 is P
The value is close to M AV. Therefore, compared to the conventional method of calculating ΔPM by (PM0-PM1), PM AV is more stable than PM1, so it is possible to reduce the judgment level PMLV2 for the transition from the steady operation state to the transient operation state. become. As a result, the timing for detecting the transient operating state becomes earlier than before, and the predicted PM value PM
The AV makes it possible to calculate the fuel injection amount close to the demand of the engine, and it is possible to improve drivability and emission.
本発明では機関の過渡運転状態の時は、前述のように予
測値PM CALを予測値PM AVとして噴射量を計算している
ため、加速運転状態等の過渡運転状態になって吸気管内
圧力が上昇する場合、その上昇に正しく見合った量の燃
料供給を行うことができ、加速応答性が大幅に向上す
る。また、機関の定常運転状態の時は、PM CALのなまし
値を予測値PM AVとしたことにより、予測値が変動する
ことがなくなり、運転性能の悪化を防止できる。In the present invention, when the engine is in the transient operating state, the injection amount is calculated by using the predicted value PM CAL as the predicted value PM AV as described above, so that the intake pipe pressure becomes the transient operating state such as the accelerated operating state. When rising, the fuel can be supplied in an amount commensurate with the rising, and the acceleration response is greatly improved. Further, when the engine is in the steady operation state, the estimated value does not fluctuate by setting the moderated value of PM CAL to the estimated value PM AV, and the deterioration of the operating performance can be prevented.
以上説明したように本発明によれば、過去及び現在のPM
値に基づいて次回の噴射時のPM値の予測演算値PM CALが
演算され、機関の過渡運転状態の時はPM CALがそのまま
予測値となり、機関の定常運転状態の時は、PM CALがな
まし処理された値が予測値となるので、機関の過渡運転
状態においては応答性が向上し、定常運転状態において
は予測値の変動に起因する噴射量の変動を排除すること
ができてドライバビリティの向上、エミッションの悪化
が防止できるという効果がある。As described above, according to the present invention, past and present PM
The predicted calculation value PM CAL of the next injection PM value is calculated based on this value, PM CAL becomes the predicted value as it is when the engine is in a transient operation state, and PM CAL is not calculated when the engine is in a steady operation state. Since the processed value becomes the predicted value, the responsiveness is improved in the transient operating state of the engine, and the fluctuation of the injection amount due to the fluctuation of the predicted value in the steady operating state can be eliminated, and drivability is improved. It is possible to prevent the deterioration of emission and the deterioration of emission.
第１図は本発明の内燃機関の空燃比制御装置の構成を示
す原理図、第２図は本発明の内燃機関の空燃比制御装置
を備えた機関の概略図、第３図は第２図の制御回路の動
作を示すフローチャート、第４図は燃料噴射、噴射量の
計算等のタイミングの説明図、第５図は機関の定常運転
状態における吸気管内圧値、そのA/D変換値、従来の方
法による吸気管内圧の予測値の変化を示す波形図、第６
図（ａ）は定常時のPM変動と、燃料噴射量の予測値の演
算周期を説明する波形図、第６図（ｂ）は実際のA/D変
換周期と燃料噴射量の予測値の演算周期を説明する波形
図である。 ２……吸気通路、３……圧力センサ、 ４……ディストリビュータ、 5,6……クランク角センサ、 ７……燃料噴射弁、10……制御回路。FIG. 1 is a principle diagram showing the configuration of an air-fuel ratio control device for an internal combustion engine according to the present invention, FIG. 2 is a schematic diagram of an engine equipped with the air-fuel ratio control device for an internal combustion engine according to the present invention, and FIG. 3 is FIG. 4 is a flow chart showing the operation of the control circuit of FIG. 4, FIG. 4 is an explanatory view of the timing of fuel injection, calculation of the injection amount, etc., and FIG. 5 is the intake pipe internal pressure value in the steady operation state of the engine, its A / D conversion value, conventional 6 is a waveform diagram showing a change in the predicted value of the intake pipe internal pressure by the method of FIG.
FIG. 6A is a waveform diagram for explaining the PM fluctuation in the steady state and the calculation cycle of the predicted value of the fuel injection amount, and FIG. 6B is the calculation of the actual A / D conversion cycle and the predicted value of the fuel injection amount. It is a waveform diagram explaining a cycle. 2 ... Intake passage, 3 ... Pressure sensor, 4 ... Distributor, 5,6 ... Crank angle sensor, 7 ... Fuel injection valve, 10 ... Control circuit.
Claims (1)
周期でA/D変換された吸入空気量の検出値を、所定クラ
ンク角毎の燃料噴射量演算タイミング時に取り込み、記
憶手段によって所定回数分記憶し、記憶された少なくと
も前回の検出値、及び最新の検出値により噴射率の吸入
空気量を予測演算手段によって予測演算し、この予測演
算による予測値と機関の回転速度とから、噴射量演算手
段が次回の燃料噴射量を演算して燃料噴射を実行する内
燃機関の空燃比制御装置において、 機関の運転状態が過渡運転状態か定常運転状態かを、機
関の運転状態の変化量によって判別する過渡・定常判別
手段と、 機関の過渡運転状態の時に、前記演算された演算値をそ
のまま予測値とし、機関の定常運転状態の時に、前記演
算値を平均化処理して予測値とする予測値設定手段と、 前記予測値を用いて前記機関の運転状態の変化量を演算
する運転状態変化量演算手段と、 を備えた内燃機関の空燃比制御装置。1. A detection value of the intake air amount A / D converted in a time cycle by an intake air amount detection means of the engine is fetched at a fuel injection amount calculation timing for each predetermined crank angle, and is stored a predetermined number of times by a storage means. Minutes are stored, and the intake air amount of the injection rate is predictively calculated by the predictive calculation means based on at least the previous detected value and the latest detected value stored, and the injection amount is calculated from the predicted value by this predictive calculation and the rotation speed of the engine. In an air-fuel ratio control device for an internal combustion engine, in which the calculation means calculates the next fuel injection amount and executes fuel injection, it is determined whether the operating state of the engine is a transient operating state or a steady operating state based on the amount of change in the operating state of the engine. When the engine is in a transient operating state, the calculated value is used as a predicted value as it is, and when the engine is in a steady operating state, the calculated value is averaged to obtain a predicted value. A prediction value setting means for air-fuel ratio control apparatus for an internal combustion engine and an operating state variation calculation means for calculating a change amount of the operating condition of the engine using the predicted value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61056894A JPH07116962B2 (en) | 1986-03-17 | 1986-03-17 | Air-fuel ratio controller for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61056894A JPH07116962B2 (en) | 1986-03-17 | 1986-03-17 | Air-fuel ratio controller for internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62214247A JPS62214247A (en) | 1987-09-21 |
| JPH07116962B2 true JPH07116962B2 (en) | 1995-12-18 |
Family
ID=13040146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61056894A Expired - Fee Related JPH07116962B2 (en) | 1986-03-17 | 1986-03-17 | Air-fuel ratio controller for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07116962B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2832944B2 (en) * | 1988-06-10 | 1998-12-09 | 株式会社日立製作所 | Measurement data delay compensation method |
| JP5573210B2 (en) * | 2010-02-04 | 2014-08-20 | トヨタ自動車株式会社 | In-cylinder intake air amount detection device |
| JP5639918B2 (en) * | 2011-02-14 | 2014-12-10 | 日立オートモティブシステムズ株式会社 | Engine intake air volume measuring device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51106475A (en) * | 1975-03-17 | 1976-09-21 | Automobile Antipollution | Atsuryokukenshutsusochi |
| JPS56107929A (en) * | 1980-01-31 | 1981-08-27 | Hitachi Ltd | Controller for internal combunstion engine |
| JPS59226870A (en) * | 1983-06-08 | 1984-12-20 | Toyota Motor Corp | Detecting method of number of revolution of engine |
-
1986
- 1986-03-17 JP JP61056894A patent/JPH07116962B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62214247A (en) | 1987-09-21 |
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