JPH0522061B2 - - Google Patents
Info
- Publication number
- JPH0522061B2 JPH0522061B2 JP3230582A JP3230582A JPH0522061B2 JP H0522061 B2 JPH0522061 B2 JP H0522061B2 JP 3230582 A JP3230582 A JP 3230582A JP 3230582 A JP3230582 A JP 3230582A JP H0522061 B2 JPH0522061 B2 JP H0522061B2
- Authority
- JP
- Japan
- Prior art keywords
- air
- fuel ratio
- amount
- ratio sensor
- fuel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000446 fuel Substances 0.000 claims description 124
- 238000002347 injection Methods 0.000 claims description 28
- 239000007924 injection Substances 0.000 claims description 28
- 238000000034 method Methods 0.000 claims description 22
- 239000000203 mixture Substances 0.000 claims description 9
- 230000003247 decreasing effect Effects 0.000 claims description 4
- 230000007423 decrease Effects 0.000 description 19
- 238000001514 detection method Methods 0.000 description 14
- 230000035945 sensitivity Effects 0.000 description 14
- 238000012937 correction Methods 0.000 description 11
- 239000003054 catalyst Substances 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- 238000000746 purification Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 239000000498 cooling water Substances 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000004043 responsiveness Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1477—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation circuit or part of it,(e.g. comparator, PI regulator, output)
- F02D41/1483—Proportional component
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、空燃比センサの特性上のばらつきを
補償して、燃料噴射量を高精度で帰還制御可能な
電子制御機関の燃料噴射方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fuel injection method for an electronically controlled engine that compensates for variations in the characteristics of an air-fuel ratio sensor and enables highly accurate feedback control of the fuel injection amount. .
［従来の技術］
従来、燃料噴射量の帰還制御では、第５図に実
線で示す如く、空燃比センサからの出力電圧
VOxに基づき、出力電圧VOxが基準電圧Vr以上
か否かによつて、機関に供給された混合気の空燃
比が目標空燃比に対し過濃側にあるのか希薄側に
あるのかを判定し、その判定結果に基づき、空燃
比が目標空燃比に対して過濃側にあるVOx≧Vr
の場合には漸減し、空燃比が目標空燃比に対して
希薄側にあるVOx＜Vrの場合には漸増する、と
いつた手順で積分量Vfを求め、この積分量Vfに
基づき燃料噴射量を算出している。[Prior Art] Conventionally, in feedback control of fuel injection amount, as shown by the solid line in Fig. 5, the output voltage from the air-fuel ratio sensor is
Based on VOx, it is determined whether the air-fuel ratio of the air-fuel mixture supplied to the engine is on the rich side or on the lean side with respect to the target air-fuel ratio, depending on whether the output voltage VOx is higher than the reference voltage Vr, Based on the determination result, VOx≧Vr when the air-fuel ratio is on the rich side with respect to the target air-fuel ratio.
If the air-fuel ratio is on the lean side with respect to the target air-fuel ratio, VOx<Vr, then the integral amount Vf is determined, and the fuel injection amount is determined based on this integral amount Vf. is being calculated.
また制御の応答性を改善するために、同図に示
す如く、上記空燃比の判定結果が反転した際に
は、その判定結果に基づき、空燃比が目標空燃比
に対して過濃側に反転した場合（即ちVOx≧Vr
となつた時点）には積分量Vfを所定のスキツプ
量RSだけ減少させ、空燃比が目標空燃比に対し
て希薄側に反転した場合（即ちVOx＜Vrとなつ
た時点）には積分量Vfを所定のスキツプ量RSだ
け増加させる、といつた手順で上記積分量Vfを
スキツプさせることも行われている。 In addition, in order to improve control responsiveness, as shown in the figure, when the judgment result of the air-fuel ratio is reversed, the air-fuel ratio is reversed to the rich side with respect to the target air-fuel ratio based on the judgment result. (i.e. VOx≧Vr
When the air-fuel ratio becomes leaner than the target air-fuel ratio (i.e., when VOx<Vr), the integral amount Vf is decreased by a predetermined skip amount RS. The above-mentioned integral amount Vf is also skipped using a procedure such as increasing Vf by a predetermined skip amount RS.
ところで空燃比センサは、第５図に点線で示す
如く、製造上のばらつき、経時変化及び劣化等に
より、検出感度が低下して出力レベルが小さくな
ることがある。そしてこの検出感度の低下が、空
燃比の過濃側と希薄側とで異なると、上記帰還制
御によつて制御される混合気の空燃比が目標空燃
比からずれてしまう。 However, as shown by the dotted line in FIG. 5, the air-fuel ratio sensor may have a lower detection sensitivity and a lower output level due to manufacturing variations, changes over time, deterioration, and the like. If the decrease in detection sensitivity differs between the rich side and the lean side of the air-fuel ratio, the air-fuel ratio of the air-fuel mixture controlled by the feedback control will deviate from the target air-fuel ratio.
そこで従来より、例えば特開昭54−99829号公
報に開示されている如く、空燃比センサからの出
力信号の極大値、極小値の大きさに基づき、上記
判定結果の反転タイミングに時間遅れを持たせる
ことにより、空燃比センサの検出感度が空燃比の
過濃側と希薄側とで異なる場合にも、積分量が、
目標空燃比に対応した基準値を中心に変化するよ
うにし、これによつて空燃比を目標空燃比に制御
できるようにしている。 Therefore, as disclosed in Japanese Patent Application Laid-Open No. 54-99829, for example, a time delay has been added to the reversal timing of the above judgment result based on the maximum value and minimum value of the output signal from the air-fuel ratio sensor. By setting, even if the detection sensitivity of the air-fuel ratio sensor differs between the rich side and the lean side of the air-fuel ratio, the integral amount is
The air-fuel ratio is changed around a reference value corresponding to the target air-fuel ratio, thereby making it possible to control the air-fuel ratio to the target air-fuel ratio.
［発明が解決しようとする課題］
しかし上記従来の制御方法では、空燃比センサ
からの出力信号に基づく空燃比の判定結果の反転
タイミングを遅延させることにより、積分量を基
準値を中心に変化させるものであるため、混合気
の空燃比を目標空燃比を中心に変化させることは
できるものの、空燃比センサの検出感度の低下に
伴い、帰還制御の応答性が低下して、空燃比が希
薄側または過濃側に維持される時間が長くなり、
触媒での排気浄化性が低下する、といつた問題を
防止することはできず、逆に悪化させてしまうこ
とがある。[Problems to be Solved by the Invention] However, in the conventional control method described above, the integral amount is changed around the reference value by delaying the reversal timing of the air-fuel ratio determination result based on the output signal from the air-fuel ratio sensor. Therefore, although it is possible to change the air-fuel ratio of the mixture around the target air-fuel ratio, as the detection sensitivity of the air-fuel ratio sensor decreases, the responsiveness of feedback control decreases, causing the air-fuel ratio to become lean. Or the time spent on the over-concentrated side increases,
It is not possible to prevent problems such as a decrease in the exhaust gas purification performance of the catalyst, and on the contrary, it may worsen the problem.
特に上記従来の方法のように、空燃比の判定結
果の反転タイミングを遅延させた場合には、その
反転周期はより長くなつてしまう。従つて上記従
来の方法では、空燃比センサの検出感度の低下に
伴う制御の応答遅れを防止することはできず、触
媒内での排気浄化性の低下を解決することができ
なかつた。 In particular, when the reversal timing of the air-fuel ratio determination result is delayed as in the conventional method described above, the reversal period becomes longer. Therefore, the conventional method described above cannot prevent a delay in control response due to a decrease in the detection sensitivity of the air-fuel ratio sensor, and cannot solve the problem of a decrease in exhaust purification performance within the catalyst.
本発明はこうした問題に鑑みなされたもので、
空燃比センサの検出感度が低下した場合に、帰還
制御による空燃比の反転周期が長くなるのを防止
して、触媒での排気浄化性を充分引き出すことの
できる電子制御帰還の燃料噴射方法を提供するこ
とを目的としている。 The present invention was made in view of these problems.
Provided is an electronically controlled feedback fuel injection method that can prevent the air-fuel ratio reversal period due to feedback control from becoming longer when the detection sensitivity of an air-fuel ratio sensor decreases, and can fully bring out the exhaust purification performance of a catalyst. It is intended to.
［課題を解決するための手段］
上記目的を達成するためになされた本発明は、
空燃比センサからの出力信号に基づき、機関に
供給された混合気の空燃比が目標空燃比に対して
過濃側にあるか希薄側にあるかを判定し、
該判定結果に応じて漸増・漸減すると共に、上
記判定結果が反転したときには該判定結果に応じ
て所定のスキツプ量にて増・減することにより、
スキツプ付き積分量を算出し、
該スキツプ付き積分量に基づいて燃料噴射量を
算出することにより帰還制御を実行する電子制御
機関の燃料噴射方法において、
上記帰還制御の実行中に、上記空燃比センサか
らの出力信号の最大値及び最小値を検出し、
該検出された最大値と最小値との偏差を算出し
て、該算出した偏差に基づき、その後上記スキツ
プ付き積分量を算出するのに使用されるスキツプ
量を、該偏差が小さい程大きな値となるように補
正することを特徴としている。[Means for Solving the Problems] The present invention, which has been made to achieve the above object, has a method of determining whether the air-fuel ratio of the air-fuel mixture supplied to the engine exceeds the target air-fuel ratio based on an output signal from an air-fuel ratio sensor. Determine whether it is on the rich side or the lean side, and increase or decrease gradually according to the determination result, and when the above determination result is reversed, increase or decrease by a predetermined skip amount according to the determination result. According to
In a fuel injection method for an electronically controlled engine, the fuel injection method for an electronically controlled engine executes feedback control by calculating a skipped integral quantity and calculates a fuel injection quantity based on the skipped integral quantity, wherein during execution of the feedback control, the air-fuel ratio sensor Detect the maximum and minimum values of the output signal from the , calculate the deviation between the detected maximum and minimum values, and then use the calculated deviation to calculate the skipped integral amount. The skip amount is corrected so that the smaller the deviation, the larger the value.
［作用及び発明の効果］
上記のように、本発明の電子制御帰還の燃料噴
射方法においては、帰還制御の実行中に検出した
空燃比センサからの出力信号の最大値と最小値と
の偏差に基づき、その後スキツプ付き積分量を算
出するのに使用するスキツプ量を、この偏差が小
さいほど大きな値となるように補正する。[Operations and Effects of the Invention] As described above, in the electronically controlled feedback fuel injection method of the present invention, the deviation between the maximum value and the minimum value of the output signal from the air-fuel ratio sensor detected during the execution of feedback control is Based on this, the skip amount used to calculate the skipped integral amount is corrected so that the smaller the deviation, the larger the value.
これは、既述したように、空燃比センサの検出
感度が低下した際には、その出力レベルも小さく
なるからである。つまり本発明では、空燃比セン
サからの出力信号の最大値と最小値との偏差を求
めることにより、空燃比センサの検出感度の低下
の程度を算出し、この偏差が小さいほど（換言す
れば空燃比センサの検出感度が低いほど）、スキ
ツプ量を大きな値となるように補正することで、
空燃比の反転周期が長くなるのを防止しているの
である。 This is because, as described above, when the detection sensitivity of the air-fuel ratio sensor decreases, its output level also decreases. In other words, in the present invention, the degree of decrease in the detection sensitivity of the air-fuel ratio sensor is calculated by determining the deviation between the maximum value and the minimum value of the output signal from the air-fuel ratio sensor, and the smaller this deviation is, the more By correcting the skip amount to a larger value, the lower the detection sensitivity of the fuel ratio sensor),
This prevents the air-fuel ratio reversal period from becoming longer.
この結果、本発明によれば、空燃比センサの検
出感度が製造上のばらつき、経時変化等により低
下しても、空燃比の反転周期が長くなるのを防止
でき、延いては触媒による排気浄化性が低下する
のを防止することが可能となる。 As a result, according to the present invention, even if the detection sensitivity of the air-fuel ratio sensor decreases due to manufacturing variations, changes over time, etc., it is possible to prevent the reversal period of the air-fuel ratio from becoming longer, and as a result, the exhaust gas purification by the catalyst can be prevented. This makes it possible to prevent a decline in performance.
なおスキツプ量の補正は、帰還制御の実行中に
検出した空燃比センサからの出力信号の最大値と
最小値との偏差に基づき行なうものであるため、
帰還制御の実行中に出力信号の最大値と最小値と
を算出する度に実行するようにしてもよく、また
帰還制御の非実行中に行うようにしてもよい。 Note that the correction of the skip amount is performed based on the deviation between the maximum value and the minimum value of the output signal from the air-fuel ratio sensor detected during the execution of feedback control.
The process may be performed each time the maximum value and minimum value of the output signal are calculated during feedback control, or may be performed while feedback control is not being performed.
［実施例］ 図面を参照して本発明の実施例を説明する。[Example] Embodiments of the present invention will be described with reference to the drawings.
第１図は電子制御燃料噴射機関の全体の概略図
であり、エアクリーナ１を通つて吸気通路２へ吸
入された空気は、運転室の加速ペダルに連動する
絞り弁３により流量を制御され、吸気分岐管４を
介して機関本体５の燃焼室へ導かれる。排気系に
は上流から順番に排気分岐管６、排気管７、およ
び三元触媒を収容する触媒コンバータ８が設けら
れている。クランク角センサ１０は機関の回転速
度をクランク軸の回転から検出する。運転室のエ
ンジンスイツチ１１はエンジンキー１２のオン
（ON）位置およびスタート（ST）位置を検出す
る。エアフローメータ１３は吸入空気流量を検出
し、吸気温センサ１４は吸気温度を検出し、水温
センサ１５はシリンダブロツクに取付けられて冷
却水温度を検出し、空燃比センサ１６は排気分岐
管６に取付けられて排気ガス中の酸素濃度を検出
しスロツトルセンサ１７は絞り弁３の開度を検出
する。クランク角センサ１０、エンジンスイツチ
１１、エアフローメータ１３、吸気温センサ１
４、水温センサ１５、空燃比センサ１６、スロツ
トルセンサ１７、および車速センサ１８の出力は
電子制御装置２０へ送られる。燃料噴射弁２１は
吸気分岐管４の各枝部分に設けられ、電子制御装
置２０からの電気パルスに応動して開閉する。 FIG. 1 is a schematic diagram of the entire electronically controlled fuel injection engine. The flow rate of air taken into the intake passage 2 through the air cleaner 1 is controlled by a throttle valve 3 that is linked to the accelerator pedal in the driver's cab. It is led to the combustion chamber of the engine body 5 via the branch pipe 4. The exhaust system is provided with, in order from upstream, an exhaust branch pipe 6, an exhaust pipe 7, and a catalytic converter 8 that accommodates a three-way catalyst. The crank angle sensor 10 detects the rotational speed of the engine from the rotation of the crankshaft. An engine switch 11 in the driver's cab detects the on (ON) position and start (ST) position of the engine key 12. The air flow meter 13 detects the intake air flow rate, the intake temperature sensor 14 detects the intake air temperature, the water temperature sensor 15 is attached to the cylinder block and detects the cooling water temperature, and the air-fuel ratio sensor 16 is attached to the exhaust branch pipe 6. The throttle sensor 17 detects the oxygen concentration in the exhaust gas, and the throttle sensor 17 detects the opening degree of the throttle valve 3. Crank angle sensor 10, engine switch 11, air flow meter 13, intake temperature sensor 1
4. The outputs of the water temperature sensor 15, air-fuel ratio sensor 16, throttle sensor 17, and vehicle speed sensor 18 are sent to the electronic control unit 20. The fuel injection valves 21 are provided at each branch portion of the intake branch pipe 4 and are opened and closed in response to electric pulses from the electronic control device 20.
第２図は電子制御装置２０のブロツク図であ
る。タイマ２５、割込み制御部２６、回転数カウ
ンタ２７、デジタル入力ポート２８、アナログ入
力ポート２９、CPU（中央処理装置）３０、
RAM（任意アクセス記憶装置）３１、ROM（読
出し専用記憶装置）３２、および燃料噴射時間制
御用カウンタ３３はバス３４を介して互いに接続
されている。回転数カウンタ２７は、クランク角
センサ１０が30゜のクランク角だけ回転するごと
に発生する出力パルスに基づいてクランク軸の１
回転につき１回、機関回転速度を測定し、測定終
了と同時に割込み制御部２６へ割込み指令信号を
送る。割込み制御部２６は回転数カウンタ２７か
ら割込み指令信号を受けると割込み信号を発生
し、CPU３０は割込み信号の発生により燃料噴
射量の算出のための割込みプログラムを実行す
る。点火スイツチ１１のスタート端子３５、スロ
ツトルセンサ１７、および車速センンサ１８の出
力信号はデジタル入力信号としてデジタル入力ポ
ート２８へ送られる。スタート端子３５からのス
タート信号は初期化を行なうために信号として用
いられる。エアフローメータ１３、吸気温センサ
１４、水温センサ１５、および空燃比センサ１６
の出力はアナログ入力信号としてアナログ入力ポ
ート２９へ送られる。アナログ入力ポート２９
は、アナログマルチプレクサとＡ／Ｄ（アナロ
グ／デジタル）変換器を含み、アナログ入力信号
を選択的にＡ／Ｄ変換する。燃料噴射時間制御用
カウンタ３３はレジスタを含むダウンカウンタか
ら成り、燃料噴射量を表表わすデジタル入力信号
に対応するパルス幅のパルスを出力として発生す
る。燃料噴射時間制御用カウンタ３３の出力パル
スは電力増幅部３６により増幅されてから燃料噴
射弁２１へ送られる。燃料噴射時間制御用カウン
タ３３の出力パルスのパルス幅はCPU３０が算
出した最終燃料噴射量に対応する。電子制御装置
２０の電力は電源回路３７により制御され、電源
回路３７はエンジンスイツチ１１のオン端子３８
を介して蓄電池３９から電力を供給される。 FIG. 2 is a block diagram of the electronic control unit 20. Timer 25, interrupt control unit 26, rotation counter 27, digital input port 28, analog input port 29, CPU (central processing unit) 30,
A RAM (random access memory) 31, a ROM (read only memory) 32, and a fuel injection time control counter 33 are connected to each other via a bus 34. The rotation number counter 27 calculates one rotation of the crankshaft based on an output pulse generated every time the crank angle sensor 10 rotates by a crank angle of 30 degrees.
The engine rotation speed is measured once per rotation, and an interrupt command signal is sent to the interrupt control section 26 at the same time as the measurement is completed. When the interrupt control unit 26 receives an interrupt command signal from the rotation number counter 27, it generates an interrupt signal, and the CPU 30 executes an interrupt program for calculating the fuel injection amount based on the generation of the interrupt signal. The output signals of the start terminal 35 of the ignition switch 11, the throttle sensor 17, and the vehicle speed sensor 18 are sent to the digital input port 28 as digital input signals. The start signal from the start terminal 35 is used as a signal for initialization. Air flow meter 13, intake temperature sensor 14, water temperature sensor 15, and air-fuel ratio sensor 16
The output of is sent to analog input port 29 as an analog input signal. Analog input port 29
includes an analog multiplexer and an A/D (analog/digital) converter to selectively A/D convert the analog input signal. The fuel injection time control counter 33 is composed of a down counter including a register, and outputs a pulse having a pulse width corresponding to a digital input signal representing the fuel injection amount. The output pulse of the fuel injection time control counter 33 is amplified by the power amplification section 36 and then sent to the fuel injection valve 21. The pulse width of the output pulse of the fuel injection time control counter 33 corresponds to the final fuel injection amount calculated by the CPU 30. The power of the electronic control device 20 is controlled by a power supply circuit 37, and the power supply circuit 37 is connected to an on terminal 38 of the engine switch 11.
Power is supplied from the storage battery 39 via the storage battery 39.
第３図は本発明を実施するプログラムのフロー
チヤートである。ステツプ43では冷却水が所定温
度Ｔ以上か否かを判別し、判別結果が正であれば
ステツプ44へ、否であればステツプ75へ進む。所
定温度Ｔは機関の暖機が終了した温度として設定
されており、冷却水が所定温度Ｔ以上である場に
は空燃比センサ１６も活性温度領域に達していて
正常な出力を発生している。ステツプ44では燃料
噴射量の帰還制御の実施期間か否かを判別し、判
別結果が正であればステツプ45へ進み、否であれ
ばステツプ75へ進む。暖機期間および減速期間で
は帰還制御は中止されている。暖機期間では燃料
噴射量の増量のため、空燃比は過濃側へ偏位し、
また減速期間では燃料遮断（燃料カツト）のため
に空燃比は希薄側へ偏位する。このように帰還制
御の中止期間では空燃比は理論空燃比に対して偏
位し、空燃比センサの出力も偏位して空燃比セン
サの正しい最大出力電圧および最小出力電圧を検
出することが困難となる。ステツプ45では空燃比
センサ１６の出力電圧VOxを検出する。ステツ
プ46では機関が所定回転速度Ｒ以上で回転してい
るか否かを判別し、判別結果が正であればステツ
プ47へ進み、否であればステツプ54へ進む。機関
が所定回転速度Ｒ未満で回転している場合では、
排気ガス量が不十分であり、空燃比センサ１６の
出力が大きな周波数で反転し、すなわち変動し易
く、適切な出力の検出は難しい。ステツプ47では
最大出力電圧VOx maxを検出する。具体的には
これまでの最大出力電圧VOx maxと今回ステツ
プ45で検出した出力電圧VOxとを比較し、VOx
≧VOx maxならばVOxを新たなVOx maxとす
る。ステツプ48では最小出力電圧VOx minを検
出する。具体的にはこれまでの最小出力電圧
VOx minと今回ステツプ45で検出した出力電圧
VOxとを比較し、VOx＜VOx minならば、
VOxを新たなVOx minとする。ステツプ49では
最大出力電圧VOx maxと最小出力電圧VOx
minとの差ΔVOx（＝VOx max−VOx min）を
算出する。ステツプ50ではΔVOxを記憶する。ス
テツプ54ではすなわち帰還制御の実施期間ではあ
るが空燃比センサ１６の出力が変動して不安定で
ある場合では、前回のΔVOxを新たなΔVOxとす
る。ステツプ58ではスキツプ用補正値ΔRSを差
ΔVOxの関数として予め定めたテーブルから今回
の差ΔVOxに対応するスキツプ用補正値ΔRSを
求める。第４図は差ΔVOxの関数として定められ
ている補正値ΔRSを表わしている。テーブルに
は適当に選択された差ΔVOxに対応するスキツプ
用補正値ΔRSのみが書込まれている。ステツプ
59ではスロツトルセンサ１２のアイドルスイツチ
がオンであるか否かを判別し、判別結果が正であ
ればステツプ60へ進み、否であればステツプ61へ
進む。アイドルスイツチは、絞り弁３がアイドリ
ング開度にある場合にはオンとなつており、アイ
ドリング開度より大きく開かれている場合にはオ
フとなつている。ステツプ60ではスキツプ用補正
値ΔRS＝０とする。スキツプ用補正値ΔRS＝０
とした理由はアイドル期間にΔRS＞０としてス
キツプを大きくすると、燃料噴射量の変動が大き
くなつて機関運転が不安定となり、これを回避す
るためである。ステツプ61では空燃比センサ１６
の出力電圧VOxが所定電圧Vr以上であるか否か
を判別し、判別結果が正であればステツプ62へ進
み、否であればステツプ68へ進む。空燃比が理論
空燃比以下である場合すなわち混合気が過濃であ
る場合、VOx≧Vrであり、空燃比が理論空燃比
より大きい場合、すなわち混合気が希薄である場
合VOx＜Vrである。ステツプ62ではVf−（RS＋
ΔRS）を新たなVfとする。ただしVfはスキツプ
付き積分量、RSはスキツプ用所定値である。RS
＋ΔRSは最終的なスキツプであり、燃料噴射量
はスキツプ付き積分量Vfに比例する。ステツプ
63ではVf−Kiを新たなKiとする。ただしKiは単
位時間当たりのスキツプ付き積分量の変化分とし
て設定された正の所定値である。ステツプ64では
空燃比センサ１６の出力電圧VOxが所定値Vr未
満が否かを判別し、判別結果が正であればこのプ
ログラムを終了し、否であればステツプ63へ戻
る。こうして、空燃比センサ１６が過濃信号を出
力するとスキツプ付き積分量Vfからスキツプと
してのRS＋ΔRSが引かれ、以降、混合気が希薄
となるまでスキツプ付き積分量Vfは所定の時間
間隔ごとにKiずつ減少する。ステツプ68ではUf
＋（RS＋ΔRS）を新たなVfとする。ステツプ69
ではVf＋Kiを新たなVfとする。ステツプ70では
空燃比センサ１６の出力電圧VOxが所定値Vr以
上であるか否かを判別し、判別結果が正であれば
このプログラムを終了し、否であればステツプ69
へ戻る。こうして空燃比センサ１６が希薄信号を
出力すると、スキツプ付き積分量Vfにスキツプ
としてのRS＋ΔRSが加算され、以降、混合気が
過濃となるまでスキツプ付積分量Vfは所定の時
間間隔ごとにKiずつ増大する。ステツプ75では
開ループ制御を行なう。 FIG. 3 is a flowchart of a program implementing the present invention. In step 43, it is determined whether or not the temperature of the cooling water is higher than a predetermined temperature T. If the determination result is positive, the process proceeds to step 44, and if not, the process proceeds to step 75. The predetermined temperature T is set as the temperature at which the engine has finished warming up, and when the cooling water is above the predetermined temperature T, the air-fuel ratio sensor 16 has also reached the active temperature range and is generating a normal output. . In step 44, it is determined whether or not it is the period for performing feedback control of the fuel injection amount. If the determination result is positive, the process proceeds to step 45, and if not, the process proceeds to step 75. Feedback control is suspended during the warm-up period and deceleration period. During the warm-up period, due to the increase in fuel injection amount, the air-fuel ratio deviates to the rich side,
Furthermore, during the deceleration period, the air-fuel ratio shifts toward the lean side due to fuel cutoff. In this way, during the feedback control suspension period, the air-fuel ratio deviates from the stoichiometric air-fuel ratio, and the output of the air-fuel ratio sensor also deviates, making it difficult to detect the correct maximum output voltage and minimum output voltage of the air-fuel ratio sensor. becomes. In step 45, the output voltage VOx of the air-fuel ratio sensor 16 is detected. In step 46, it is determined whether the engine is rotating at a predetermined rotational speed R or higher. If the result of the determination is positive, the process proceeds to step 47, and if not, the process proceeds to step 54. If the engine is rotating below the predetermined rotational speed R,
The amount of exhaust gas is insufficient, and the output of the air-fuel ratio sensor 16 is likely to invert at a large frequency, that is, to fluctuate, making it difficult to detect an appropriate output. In step 47, the maximum output voltage VOx max is detected. Specifically, the previous maximum output voltage VOx max is compared with the output voltage VOx detected in step 45 this time, and VOx
If ≧VOx max, set VOx as the new VOx max. In step 48, the minimum output voltage VOx min is detected. Specifically, the lowest output voltage to date
VOx min and the output voltage detected in step 45 this time
Compare with VOx, and if VOx＜VOx min,
Let VOx be the new VOx min. In step 49, the maximum output voltage VOx max and the minimum output voltage VOx
Calculate the difference ΔVOx (=VOx max−VOx min) from min. At step 50, ΔVOx is stored. In step 54, if the output of the air-fuel ratio sensor 16 fluctuates and is unstable during the feedback control execution period, the previous ΔVOx is set as the new ΔVOx. In step 58, the skip correction value ΔRS corresponding to the current difference ΔVOx is determined from a predetermined table using the skip correction value ΔRS as a function of the difference ΔVOx. FIG. 4 represents the correction value ΔRS which is determined as a function of the difference ΔVOx. Only the skip correction value ΔRS corresponding to the appropriately selected difference ΔVOx is written in the table. step
At step 59, it is determined whether or not the idle switch of the throttle sensor 12 is on. If the determination result is positive, the process proceeds to step 60, and if not, the process proceeds to step 61. The idle switch is turned on when the throttle valve 3 is at the idling opening, and is turned off when the throttle valve 3 is opened more than the idling opening. In step 60, the skip correction value ΔRS is set to 0. Skip correction value ΔRS=0
The reason for this is that if ΔRS>0 and the skip is increased during the idle period, fluctuations in the fuel injection amount will increase and engine operation will become unstable, and this is to be avoided. In step 61, the air-fuel ratio sensor 16
It is determined whether the output voltage VOx of is equal to or higher than a predetermined voltage Vr, and if the determination result is positive, the process proceeds to step 62, and if not, the process proceeds to step 68. When the air-fuel ratio is less than or equal to the stoichiometric air-fuel ratio, that is, when the air-fuel mixture is too rich, VOx≧Vr, and when the air-fuel ratio is greater than the stoichiometric air-fuel ratio, that is, when the air-fuel mixture is lean, VOx<Vr. In step 62, Vf-(RS+
ΔRS) is the new Vf. However, Vf is an integral quantity with skipping, and RS is a predetermined value for skipping. R.S.
+ΔRS is the final skip, and the fuel injection amount is proportional to the integral amount with skip Vf. step
In 63, Vf−Ki is the new Ki. However, Ki is a positive predetermined value set as a change in the skipped integral amount per unit time. In step 64, it is determined whether the output voltage VOx of the air-fuel ratio sensor 16 is less than a predetermined value Vr. If the determination result is positive, the program is terminated; if not, the program returns to step 63. In this way, when the air-fuel ratio sensor 16 outputs a rich signal, RS + ΔRS as a skip is subtracted from the integral amount Vf with skip, and from then on, the integral amount Vf with skip is increased by Ki at predetermined time intervals until the air-fuel mixture becomes lean. Decrease. Uf in step 68
+(RS+ΔRS) is the new Vf. step 69
Now let Vf + Ki be the new Vf. In step 70, it is determined whether the output voltage VOx of the air-fuel ratio sensor 16 is greater than or equal to a predetermined value Vr, and if the determination result is positive, this program is terminated, and if not, step 69 is performed.
Return to When the air-fuel ratio sensor 16 outputs a lean signal in this way, RS + ΔRS as a skip is added to the integral amount Vf with skip, and from then on, the integral amount Vf with skip is increased by Ki at predetermined time intervals until the air-fuel mixture becomes rich. increase In step 75, open loop control is performed.
第５図は空燃比センサ１６の出力電圧およびス
キツプ付き積分量の時間変化を示している。なお
図において実線は空燃比センサ１６の出力電圧が
正常である場合、点線は空燃比センサ１６の出力
電圧が製造上のばらつき、経時変化等によりなも
のからずれている場合（即ち、空燃比センサ１６
の検出感度が低下している場合）、二点鎖線は本
実施例により空燃比センサ１６の出力電圧を補償
した場合の特性を示している。 FIG. 5 shows temporal changes in the output voltage of the air-fuel ratio sensor 16 and the integral amount with skip. In the figure, the solid line indicates when the output voltage of the air-fuel ratio sensor 16 is normal, and the dotted line indicates when the output voltage of the air-fuel ratio sensor 16 deviates from the normal value due to manufacturing variations, changes over time, etc. 16
(when the detection sensitivity of the air-fuel ratio sensor 16 is lowered), the two-dot chain line shows the characteristics when the output voltage of the air-fuel ratio sensor 16 is compensated according to this embodiment.
この図から明らかなように、本実施例によれ
ば、製造上のばらつき、経時変化等により、空燃
比センサの検出感度が低下したとしても、その低
下の程度を空燃比センサ１６の出力電圧VOxの
最大値VOx minと最小値VOmaxとの差ΔVOx
により検出し、その差ΔVOxが小さいほど（換言
すれば空燃比センサ１６の検出感度の低下の度合
いが大きいほど）、スキツプ用補正値ΔRSを大き
い値に設定して、スキツプ付き積分量を大きくス
キツプさせるので、空燃比センサの検出感度の低
下に伴い、空燃比の反転周期が長くなるのを防止
でき、延いては触媒による排気浄化性が低下する
のを防止することが可能となる。 As is clear from this figure, according to this embodiment, even if the detection sensitivity of the air-fuel ratio sensor decreases due to manufacturing variations, changes over time, etc., the degree of the decrease is determined by the output voltage VOx of the air-fuel ratio sensor 16. The difference between the maximum value VOx min and the minimum value VOmax ΔVOx
The smaller the difference ΔVOx (in other words, the greater the degree of decrease in the detection sensitivity of the air-fuel ratio sensor 16), the larger the skipping correction value ΔRS is set to increase the skipped integral amount. Therefore, it is possible to prevent the reversal period of the air-fuel ratio from becoming longer due to a decrease in the detection sensitivity of the air-fuel ratio sensor, and it is also possible to prevent the exhaust gas purification performance of the catalyst from decreasing.
また本実施例では、スキツプ用補正値ΔRSを
算出するための差ΔVOxの演算処理（ステツプ47
〜ステツプ50）を、空燃比センサ１６の出力が不
安定となる機関の低回転時には禁止し、差ΔVOx
には、前回求めた差ΔVOxをそのまま設定するよ
うにしている。このため機関回転に伴う空燃比セ
ンサ１６の出力特性変化によつて、スキツプ量を
補正してしまうのを防止できる。 In addition, in this embodiment, calculation processing of the difference ΔVOx (step 47) is performed to calculate the skip correction value ΔRS.
~Step 50) is prohibited at low engine speeds when the output of the air-fuel ratio sensor 16 is unstable, and the difference ΔVOx is
, the previously determined difference ΔVOx is set as is. Therefore, it is possible to prevent the skip amount from being corrected due to changes in the output characteristics of the air-fuel ratio sensor 16 as the engine rotates.
また更に本実施例では、アイドルスイツチのオ
ン時、即ち機関のアイドル運転時には、スキツプ
用補正値ΔRSを０とするようにしている。この
ため機関のアイドル運転時に、燃料噴射量の変動
が大きくなつて、機関回転が不安定となるのを防
止することもできる。 Furthermore, in this embodiment, the skip correction value ΔRS is set to 0 when the idle switch is on, that is, when the engine is running at idle. Therefore, it is possible to prevent the engine rotation from becoming unstable due to large fluctuations in the fuel injection amount during idling operation of the engine.
第１図は本発明が適用される電子制御機関の概
略図、第２図は第１図の電子制御装置の詳細なブ
ロツク図、第３図は本発明を実施するプログラム
のフローチヤート、第４図は空燃比センサの出力
電圧の差ΔVOxとスキツプ補正値との関係を示す
グラフ、第５図は空燃比センサの出力特性とスキ
ツプ付き積分量との時間変化を示すグラフであ
る。
１０…クランク角センサ、１５…水温センサ、
１６…空燃比センサ、２０…電子制御装置、３０
…CPU。
FIG. 1 is a schematic diagram of an electronic control engine to which the present invention is applied, FIG. 2 is a detailed block diagram of the electronic control device shown in FIG. 1, FIG. 3 is a flowchart of a program for implementing the present invention, and FIG. The figure is a graph showing the relationship between the output voltage difference ΔVOx of the air-fuel ratio sensor and the skip correction value, and FIG. 10...Crank angle sensor, 15...Water temperature sensor,
16...Air-fuel ratio sensor, 20...Electronic control device, 30
…CPU.
Claims (1)
に供給された混合気の空燃比が目標空燃比に対し
て過濃側にあるか希薄側にあるかを判定し、 該判定結果に応じて漸増・漸減すると共に、上
記判定結果が反転したときには該判定結果に応じ
て所定のスキツプ量にて増・減することにより、
スキツプ付き積分量を算出し、 該スキツプ付き積分量に基づいて燃料噴射量を
算出することにより帰還制御を実行する電子制御
機関の燃料噴射方法において、 上記帰還制御の実行中に、上記空燃比センサか
らの出力信号の最大値及び最小値を検出し、 該検出された最大値と最小値との偏差を算出し
て、該算出した偏差に基づき、その後上記スキツ
プ付き積分量を算出するのに使用されるスキツプ
量を、該偏差が小さいい程大きな値となるように
補正することを特徴とする電子制御機関の燃料噴
射方法。[Claims] 1. Based on the output signal from the air-fuel ratio sensor, it is determined whether the air-fuel ratio of the air-fuel mixture supplied to the engine is on the rich side or lean side with respect to the target air-fuel ratio, By gradually increasing or decreasing depending on the determination result, and increasing or decreasing by a predetermined skip amount according to the determination result when the determination result is reversed,
In a fuel injection method for an electronically controlled engine, the fuel injection method for an electronically controlled engine executes feedback control by calculating a skipped integral amount and calculates a fuel injection amount based on the skipped integral amount, wherein the air-fuel ratio sensor Detect the maximum and minimum values of the output signal from the , calculate the deviation between the detected maximum and minimum values, and then use the calculated deviation to calculate the skipped integral amount. A fuel injection method for an electronically controlled engine, characterized in that the skip amount is corrected so that the smaller the deviation, the larger the skip amount.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3230582A JPS58150038A (en) | 1982-03-03 | 1982-03-03 | Fuel injection method of electronically controlled engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3230582A JPS58150038A (en) | 1982-03-03 | 1982-03-03 | Fuel injection method of electronically controlled engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58150038A JPS58150038A (en) | 1983-09-06 |
| JPH0522061B2 true JPH0522061B2 (en) | 1993-03-26 |
Family
ID=12355233
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3230582A Granted JPS58150038A (en) | 1982-03-03 | 1982-03-03 | Fuel injection method of electronically controlled engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58150038A (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4739614A (en) * | 1985-02-22 | 1988-04-26 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system in internal combustion engine |
| USRE33942E (en) * | 1985-02-22 | 1992-06-02 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system in internal combustion engine |
| JPH066913B2 (en) * | 1985-02-23 | 1994-01-26 | トヨタ自動車株式会社 | Air-fuel ratio controller for internal combustion engine |
| US4729219A (en) * | 1985-04-03 | 1988-03-08 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system having improved response characteristics |
| US4745741A (en) * | 1985-04-04 | 1988-05-24 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system having improved response characteristics |
| JPH07113336B2 (en) * | 1985-04-09 | 1995-12-06 | トヨタ自動車株式会社 | Air-fuel ratio controller for internal combustion engine |
| CA1252180A (en) * | 1985-04-09 | 1989-04-04 | Yoshiki Chujo | Double air-fuel ratio sensor system having improved response characteristics |
| JPH0639930B2 (en) * | 1985-04-12 | 1994-05-25 | トヨタ自動車株式会社 | Air-fuel ratio controller for internal combustion engine |
| US4707984A (en) * | 1985-04-15 | 1987-11-24 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system having improved response characteristics |
| CA1268529A (en) * | 1985-07-31 | 1990-05-01 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system carrying out learning control operation |
| JPS6260941A (en) * | 1985-09-10 | 1987-03-17 | Toyota Motor Corp | Air-fuel ratio controller for internal combustion engine |
| US4723408A (en) * | 1985-09-10 | 1988-02-09 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system carrying out learning control operation |
| US4707985A (en) * | 1985-09-12 | 1987-11-24 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system carrying out learning control operation |
| US4747265A (en) * | 1985-12-23 | 1988-05-31 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system having improved exhaust emission characteristics |
| JP2570265B2 (en) * | 1986-07-26 | 1997-01-08 | トヨタ自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
| US4817384A (en) * | 1986-08-13 | 1989-04-04 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system having improved exhaust emission characteristics |
| US4840027A (en) * | 1986-10-13 | 1989-06-20 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system having improved exhaust emission characteristics |
| JPH0726577B2 (en) * | 1986-10-13 | 1995-03-29 | トヨタ自動車株式会社 | Air-fuel ratio controller for internal combustion engine |
| JPS6397851A (en) * | 1986-10-13 | 1988-04-28 | Toyota Motor Corp | Air-fuel ratio control device for internal combustion engine |
| JPH0778373B2 (en) * | 1986-10-13 | 1995-08-23 | トヨタ自動車株式会社 | Air-fuel ratio controller for internal combustion engine |
| JPH0718366B2 (en) * | 1986-11-08 | 1995-03-06 | トヨタ自動車株式会社 | Air-fuel ratio controller for internal combustion engine |
| US4809501A (en) * | 1987-01-16 | 1989-03-07 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system having improved exhaust emission characteristics |
| US4881368A (en) * | 1987-02-09 | 1989-11-21 | Toyota Jidosha Kabushiki Kaisha | Double air-fuel ratio sensor system having improved exhaust emission characteristics |
| US4964271A (en) * | 1987-03-06 | 1990-10-23 | Toyota Jidosha Kabushiki Kaisha | Air-fuel ratio feedback control system including at least downstream-side air-fuel ratio sensor |
| JPS6415448A (en) * | 1987-07-10 | 1989-01-19 | Toyota Motor Corp | Air-fuel ratio control device for internal combustion engine |
| JP2526591B2 (en) * | 1987-07-20 | 1996-08-21 | トヨタ自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
| JP2600208B2 (en) * | 1987-10-20 | 1997-04-16 | トヨタ自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
| JP3009668B2 (en) * | 1988-03-01 | 2000-02-14 | トヨタ自動車株式会社 | Air-fuel ratio control device for internal combustion engine |
| US4970858A (en) * | 1988-03-30 | 1990-11-20 | Toyota Jidosha Kabushiki Kaisha | Air-fuel ratio feedback system having improved activation determination for air-fuel ratio sensor |
-
1982
- 1982-03-03 JP JP3230582A patent/JPS58150038A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58150038A (en) | 1983-09-06 |
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