JPS638293B2 - - Google Patents
Info
- Publication number
- JPS638293B2 JPS638293B2 JP54043011A JP4301179A JPS638293B2 JP S638293 B2 JPS638293 B2 JP S638293B2 JP 54043011 A JP54043011 A JP 54043011A JP 4301179 A JP4301179 A JP 4301179A JP S638293 B2 JPS638293 B2 JP S638293B2
- Authority
- JP
- Japan
- Prior art keywords
- feedback control
- comparison reference
- reference potential
- output signal
- exhaust sensor
- 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
Links
- 239000000446 fuel Substances 0.000 claims description 32
- 238000002485 combustion reaction Methods 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 6
- 239000001301 oxygen Substances 0.000 claims description 6
- 229910052760 oxygen Inorganic materials 0.000 claims description 6
- 239000007789 gas Substances 0.000 claims description 5
- 239000000203 mixture Substances 0.000 description 13
- 101100219315 Arabidopsis thaliana CYP83A1 gene Proteins 0.000 description 7
- 101100269674 Mus musculus Alyref2 gene Proteins 0.000 description 7
- 101100140580 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) REF2 gene Proteins 0.000 description 7
- 238000000034 method Methods 0.000 description 6
- 101000806846 Homo sapiens DNA-(apurinic or apyrimidinic site) endonuclease Proteins 0.000 description 5
- 101000835083 Homo sapiens Tissue factor pathway inhibitor 2 Proteins 0.000 description 5
- 102100026134 Tissue factor pathway inhibitor 2 Human genes 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 239000000498 cooling water Substances 0.000 description 3
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 101100152598 Arabidopsis thaliana CYP73A5 gene Proteins 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- 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】
本発明は内燃機関の空燃比帰還制御装置に関
し、特に内燃機関の燃料供給量を演算するデジタ
ル計算機と、機関の排気管に取付けられ排気ガス
内の酸素濃度を検知する排気センサとを有し、排
気センサの出力信号を比較基準電位と比較して、
排気センサ出力信号レベルが帰還制御可能状態に
あると判定された時、排気センサ出力信号により
上記デジタル計算機の演算結果を修正して空燃比
を所望値に帰還制御する空燃比帰還制御装置に関
する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air-fuel ratio feedback control device for an internal combustion engine, and more particularly to a digital computer that calculates the amount of fuel supplied to the internal combustion engine, and a digital computer that is attached to the exhaust pipe of the engine to detect the oxygen concentration in the exhaust gas. an exhaust sensor, and compares the output signal of the exhaust sensor with a comparison reference potential,
The present invention relates to an air-fuel ratio feedback control device that feedback-controls the air-fuel ratio to a desired value by correcting the calculation result of the digital computer based on the exhaust sensor output signal when it is determined that the exhaust sensor output signal level is in a feedback-controllable state.
上述の型式の空燃比帰還制御装置については
種々の提案がある。しかし排気ガスの酸素濃度を
検知する排気センサ即ちO2センサは低温度にな
れば内部抵抗が著しく増大して起電力も低下する
特性を有するため所定温度以下では空燃比の２状
態即ち“濃”“薄”混合気の状態を弁別できなく
なる。 There are various proposals for air-fuel ratio feedback control devices of the type described above. However, the exhaust sensor that detects the oxygen concentration of exhaust gas, that is, the O 2 sensor, has the characteristic that the internal resistance increases significantly and the electromotive force decreases when the temperature becomes low. It becomes impossible to distinguish between “lean” air-fuel mixtures.
このため、従来の装置では大別して次の２方式
を使用する。第１は帰還制御領域はO2センサ温
度が所定値以上の時に限定する。センサ信号の入
力回路はセンサ信号を電圧検知し、それを比較基
準電位と比較する基本構成とする。センサ温度は
直接測定せず、冷却水温等によつて推定する場合
が多い。第２はO2センサに所定の電流を外部か
ら流しこむことによつてセンサの内部抵抗の変化
を監視し、内部抵抗が所定値以下となつた時に帰
還制御を開始する。 For this reason, conventional devices use the following two methods. First, the feedback control region is limited to when the O 2 sensor temperature is above a predetermined value. The sensor signal input circuit has a basic configuration that detects the voltage of the sensor signal and compares it with a comparison reference potential. Sensor temperature is often not measured directly, but estimated based on cooling water temperature, etc. Second, by flowing a predetermined current into the O 2 sensor from the outside, changes in the internal resistance of the sensor are monitored, and feedback control is started when the internal resistance falls below a predetermined value.
上述の第１の方式の欠点は、入力回路構成は比
較的簡単であるが、所定のO2センサ温度は比較
的高温度に設定する必要があり、帰還制御領域が
狭くなる。更に、O2センサ温度と冷却水温との
間には一義的な関係はなく、誤動作を生ずること
が多い。第２の方式の欠点は、帰還制御領域は広
くなるが排気センサに電流を流しこむ回路および
排気センサの出力信号レベルを抵抗分圧された比
較基準電位と比較して帰還制御可能状態にあるか
否かを判定する回路等が必要になり、回路が著し
く複雑になることである。この場合、帰還制御可
能状態の判定には、第１の比較基準電位と第２の
比較基準電位とを設定し、排気センサが低温で内
部抵抗の大きい時は、排気センサ出力信号レベル
が上記第１、第２の比較基準電位の間に存在する
が、排気センサの内部抵抗が所定値以下になる
と、排気センサ出力信号レベルが上記第１、第２
の比較基準電位の間から逸脱することで帰還制御
可能状態と判定する方法が好んで用いられる。こ
れは、混合気の“濃”または“薄”のいずれの状
態からでも帰還制御を速やかに開始できるという
理由によるものであるが、“濃”状態から帰還制
御を開始した場合、当初は排気センサの応答が遅
いため、帰還制御開始後“薄”混合気になつた状
態を排気センサが検知するまでに比較的長時間を
要し、このため過渡的に機関は過薄混合気運転を
続け、機関回転数が低下してエンジン停止に至る
可能性もあつた。 The disadvantage of the first method described above is that although the input circuit configuration is relatively simple, the predetermined O 2 sensor temperature must be set to a relatively high temperature, and the feedback control area becomes narrow. Furthermore, there is no unambiguous relationship between the O 2 sensor temperature and the cooling water temperature, which often causes malfunctions. The disadvantage of the second method is that the feedback control area becomes wider, but the feedback control is not possible by comparing the circuit that supplies current to the exhaust sensor and the output signal level of the exhaust sensor with a comparison reference potential divided by a resistor. A circuit or the like is required to determine whether or not this is the case, and the circuit becomes extremely complicated. In this case, a first comparison reference potential and a second comparison reference potential are set to determine whether the feedback control is possible, and when the exhaust sensor is at a low temperature and has a large internal resistance, the exhaust sensor output signal level is set to the above-mentioned 1 and the second comparison reference potential, but when the internal resistance of the exhaust sensor becomes equal to or less than a predetermined value, the exhaust sensor output signal level becomes the first and second comparison reference potentials.
A method is preferably used in which it is determined that feedback control is possible by deviating from a comparison reference potential of . This is because feedback control can be started quickly regardless of whether the air-fuel mixture is rich or lean. However, if feedback control is started from a rich state, the exhaust sensor Because of the slow response, it takes a relatively long time for the exhaust sensor to detect that the mixture has become "lean" after starting feedback control, and as a result, the engine continues to operate with a lean mixture temporarily. There was also the possibility that the engine speed would drop and the engine would stop.
近年デジタル計算機を使用して機関の制御が行
なわれるシステムが多いが、空燃比帰還制御装置
として、制御可能領域が広く、回路構成が簡単な
O2センサ出力信号のデジタル演算処理方式は使
用されていない。 In recent years, many systems use digital computers to control engines, but air-fuel ratio feedback control devices have a wide controllable range and a simple circuit configuration.
Digital calculation processing method of O2 sensor output signal is not used.
本発明の目的は、上述の第２の方式による帰還
制御装置において、O2センサの信号処理をマイ
クロプロセサのプログラムとして行うことによ
り、回路構成が簡単で、帰還制御領域が広く、混
合気の“濃”、“薄”いずれの状態からでも空燃比
帰還制御を速やかに開始でき、かつ“濃”状態か
らの帰還制御開始時に過渡的に機関の回転低下を
起こすこともなく、適切な制御が行える空燃比帰
還制御装置を提供することにある。 An object of the present invention is to provide a feedback control device according to the second method described above, in which the signal processing of the O 2 sensor is performed as a microprocessor program, so that the circuit configuration is simple, the feedback control area is wide, and the air-fuel mixture " Air-fuel ratio feedback control can be started immediately in either the rich or lean state, and appropriate control can be performed without causing a transient drop in engine speed when starting feedback control from the rich state. An object of the present invention is to provide an air-fuel ratio feedback control device.
第５図は、本発明の機能を示すブロツク図であ
る。第５図において、排気センサ１００は、内燃
機関の排気ガス中の酸素濃度に対応した信号を出
力する。また、電流流し込み回路１０１は、所定
の電圧を抵抗により分圧し、上記分圧電位点から
抵抗を介して上記排気センサとの接続点に電流を
流しこむ回路であり、例えば後記第２図の５のご
ときものである。また、入力回路１０２は、上記
接続点からの排気センサ出力信号を増幅しＡ／Ｄ
変換してマイクロプロセサ（破線で囲んだ部分）
に入力するものである。また、上記マイクロプロ
セツサの機能としては、下記の各手段がある。す
なわち、第１比較基準電位設定手段１０３は、第
１の比較基準電位（空燃比の濃状態側の基準とな
る高い方の値）を設定し、第２比較基準電位設定
手段１０４は上記第１の比較基準電位より低い第
２の比較基準電位（空燃比の希薄状態側の基準と
なる低い方の値）を設定する。また、判定手段１
０５は、排気センサ出力信号レベルが上記第１、
第２の比較基準電位の間から逸脱した時に帰還制
御可能状態と判定して空燃比帰還制御手段に帰還
制御を開始させ、排気センサ出力信号レベルが上
記第１、第２の比較基準レベルの間に所定時間存
在することを判別して帰還制御を停止させるもの
である。また、比較基準電位変更手段１０６は、
排気センサ出力信号レベルが上記第１の比較基準
電位を超えて帰還制御が開始された時に上記第２
比較基準電位を初期設定値よりも上昇した他の設
定値に移行させ、その後所定の割合で上記設定値
を下降させて初期設定値または他の設定値に向つ
て変化させるものである。なお、空燃比帰還制御
手段は、従来と同様に、排気センサ出力信号に応
じてデジタル計算機における演算結果を修正して
空燃比を所望値に帰還制御する。 FIG. 5 is a block diagram showing the functionality of the present invention. In FIG. 5, an exhaust sensor 100 outputs a signal corresponding to the oxygen concentration in the exhaust gas of the internal combustion engine. The current injecting circuit 101 is a circuit that divides a predetermined voltage using a resistor and injects a current from the divided potential point to the connection point with the exhaust sensor through the resistor. It is something like this. In addition, the input circuit 102 amplifies the exhaust sensor output signal from the connection point and outputs the A/D signal.
Convert it to a microprocessor (the part surrounded by the dashed line)
This is what you input. Further, the functions of the microprocessor include the following means. That is, the first comparison reference potential setting means 103 sets a first comparison reference potential (the higher value serving as the reference for the rich state of the air-fuel ratio), and the second comparison reference potential setting means 104 sets the first comparison reference potential (the higher value serving as a reference for the rich air-fuel ratio). A second comparison reference potential (a lower value serving as a reference for the lean state of the air-fuel ratio) is set lower than the comparison reference potential of . In addition, determination means 1
05, the exhaust sensor output signal level is the first,
When the exhaust sensor output signal level deviates from between the second comparison reference level, it is determined that the feedback control is possible, and the air-fuel ratio feedback control means starts the feedback control, and the exhaust sensor output signal level is between the first and second comparison reference levels. The feedback control is stopped by determining that the feedback control exists for a predetermined period of time. Further, the comparison reference potential changing means 106
When the exhaust sensor output signal level exceeds the first comparison reference potential and feedback control is started, the second
The comparison reference potential is shifted to another set value that is higher than the initial set value, and then the set value is lowered at a predetermined rate to change toward the initial set value or another set value. Note that the air-fuel ratio feedback control means feedback-controls the air-fuel ratio to a desired value by correcting the calculation result in the digital computer according to the exhaust sensor output signal, as in the prior art.
上記のごとく、本発明においては、マイクロプ
ロセツサのプログラムによつて比較基準電位の設
定、比較、演算などを行うことにより、アナログ
制御システムやワイヤロジツクシステムで必要と
した複雑な比較判定回路は不要で、回路構成が簡
単となり、また“濃”状態からの帰還制御開始時
に上記他方の比較基準電位を初期設定値から上昇
した他の設定値に移行させ、その後所定割合で上
記設定値を下降させて初期設定値または他の設定
値に向つて変化させることもソフト的手法で容易
にでき、これにより“濃”状態からの帰還制御開
始時にも機関の回転低下を起こさずに適切な制御
を行うことができる。 As described above, in the present invention, by setting the comparison reference potential, comparing, calculating, etc. using a microprocessor program, the complicated comparison/judgment circuit required in an analog control system or wire logic system can be eliminated. It is unnecessary, the circuit configuration is simple, and at the start of feedback control from the "rich" state, the other comparison reference potential is shifted from the initial setting value to another setting value, and then the above setting value is lowered at a predetermined rate. It is also possible to easily change the value to the initial set value or another set value using a software method, and this allows appropriate control to be performed without causing a drop in engine speed even when starting feedback control from a "rich" state. It can be carried out.
本発明を例示とした実施例並びに図面について
説明する。 Embodiments and drawings illustrating the present invention will be described.
第１図は本発明による空燃比帰還制御装置を適
用するに好適なデジタル計算機による内燃機関制
御装置のブロツク線図を示す。車両及び内燃機関
の種々の状態を検知するセンサ群１、例えば排気
管に取付けて排気ガス中の酸素濃度を検出する
O2センサ１１、クランクと共働して機関の回転
速度と回転の位相とを検出するクランク角センサ
１２、シリンダの冷却水温度を検出する水温セン
サ１３等、からの出力をインターフエース２を介
して演算処理装置（CPU）４に入力する。イン
ターフエース２はセンサ群１からの入力信号の取
りこみＡ／Ｄ変換、データの保持等を行う。
CPU４はこの入力信号を所要の時に取りこみ、
所要の演算を行つて作動信号データを作成し、イ
ンターフエース２を介してアクチユエータ群３の
所要のアクチユエータ、例えば燃料噴射弁３１、
点火装置３２、排気還流弁３３を作動させる。 FIG. 1 shows a block diagram of an internal combustion engine control system using a digital computer suitable for applying the air-fuel ratio feedback control system according to the present invention. Sensor group 1 that detects various states of the vehicle and internal combustion engine, for example, is attached to the exhaust pipe to detect the oxygen concentration in the exhaust gas
Outputs from the O 2 sensor 11, the crank angle sensor 12 which works with the crank to detect the rotational speed and rotational phase of the engine, and the water temperature sensor 13 which detects the cylinder cooling water temperature are sent via the interface 2. and input it to the arithmetic processing unit (CPU) 4. The interface 2 takes input signals from the sensor group 1, performs A/D conversion, holds data, and the like.
CPU4 takes in this input signal at the required time,
The required calculations are performed to create actuation signal data, and the data is sent to the required actuators of the actuator group 3, such as the fuel injection valve 31, via the interface 2.
The ignition device 32 and exhaust recirculation valve 33 are activated.
排気中の酸素濃度を検出するO2センサの出力
は基準値と比較して“濃”“薄”混合気の信号と
なり、CPUはこの信号に応じて吸入空気量基準
の演算燃料噴射量を修正して空燃比を所要の値に
保つ。この制御を空燃比帰還制御と称する。 The output of the O 2 sensor that detects the oxygen concentration in the exhaust becomes a signal of "rich" or "lean" mixture compared to the reference value, and the CPU corrects the calculated fuel injection amount based on the intake air amount according to this signal. to maintain the air-fuel ratio at the desired value. This control is called air-fuel ratio feedback control.
第２図は本発明によるO2センサ信号処理回路
を示す。O2センサ１１の等価回路として内部抵
抗１１１と内部超電力１１２を示す。O2センサ
１１への電流流しこみ回路５はO2センサ１１に
接続され、所定電圧＋Ｂを抵抗分圧する構成であ
る。O2センサ１１の出力信号は信号増巾器６で
増巾される。信号増巾器６の出力はインターフエ
ース２１に供給されてＡ／Ｄ変換され、CPU４
との間で信号の受け渡しを行う。電流流しこみ回
路５においては所定電圧＋Ｂを抵抗５１，５２に
よつて分圧し抵抗５３を経てO2センサ１１に電
流を流しこむ。CPU４はＡ／Ｄ変換されたO2セ
ンサ出力信号を適時取りこんで、本発明によつて
ソフトウエアプログラムの制御によつて信号の処
理及び帰還制御のための演算を行う。 FIG. 2 shows an O 2 sensor signal processing circuit according to the present invention. An internal resistance 111 and an internal superpower 112 are shown as an equivalent circuit of the O 2 sensor 11. The circuit 5 for supplying current to the O 2 sensor 11 is connected to the O 2 sensor 11 and has a configuration in which a predetermined voltage +B is divided into resistors. The output signal of the O 2 sensor 11 is amplified by a signal amplifier 6. The output of the signal amplifier 6 is supplied to the interface 21, where it is A/D converted and sent to the CPU 4.
Signals are exchanged between the In the current injecting circuit 5, a predetermined voltage +B is divided by resistors 51 and 52, and a current is injected into the O 2 sensor 11 via the resistor 53. The CPU 4 timely takes in the A/D converted O 2 sensor output signal and processes the signal and performs calculations for feedback control under the control of a software program according to the present invention.
第２図の回路の動作を説明する。機関始動後に
排気管が加熱されるまでの間はO2センサ温度が
低く、内部抵抗値は高く、応答が遅い。従つてこ
の時期は帰還制御を行うことはできない。この時
の端子電位VSは電流流しこみ回路５の分圧電位
VOとほぼ等しい値となつている。第３図はO2セ
ンサ１１の内部抵抗１１１の値ρの変化に応じて
VSの値の変化を示す。第３図の部分ＡがO2セン
サ低温状態を示す。ρの値は矢印に示す通り左方
が大きい。 The operation of the circuit shown in FIG. 2 will be explained. After the engine starts until the exhaust pipe is heated, the O 2 sensor temperature is low, the internal resistance value is high, and the response is slow. Therefore, feedback control cannot be performed during this period. The terminal potential V S at this time is the divided voltage potential of the current injecting circuit 5.
The value is almost equal to V O. Figure 3 shows the change in the value ρ of the internal resistance 111 of the O 2 sensor 11.
It shows the change in the value of V S. Part A of FIG. 3 shows the O 2 sensor low temperature state. The value of ρ is larger on the left side as shown by the arrow.
O2センサ１１の温度が上昇し、内部抵抗値ρ
が減少すれば、電圧VSには内部起電力１１２の
影響が生ずる。機関の混合比が理論空燃比よりも
“濃”い状態であれば約0.8Vの内部起電力を発生
し、“薄”い状態であれば約0.1Vの値を出力す
る。従つて端子電位VSはO2センサ内部抵抗の低
下と共に部分Ｂに示す変化となる。ソフトウエア
プログラムの中に基準電位VREF1，VREF2を設定し
ておけば基準電位と端子電位VSとを比較するこ
とによつてO2センサ内部抵抗値の監視を行なう
ことが可能となる。即ち、VSがVREF1より大とな
つた時に帰還制御可能状態と判断し、帰還制御開
始信号を発生する。同様に“薄”い混合気の場合
はVSがVREF2よりも低くなつた時に帰還制御可能
と判断する。 The temperature of the O2 sensor 11 rises, and the internal resistance value ρ
If the voltage V S decreases, the internal electromotive force 112 will affect the voltage V S . If the engine's mixture ratio is richer than the stoichiometric air-fuel ratio, it will generate an internal electromotive force of approximately 0.8V, and if it is lean, it will output a value of approximately 0.1V. Therefore, the terminal potential V S changes as shown in part B as the internal resistance of the O 2 sensor decreases. By setting the reference potentials V REF1 and V REF2 in the software program, it becomes possible to monitor the internal resistance value of the O 2 sensor by comparing the reference potential and the terminal potential V S . That is, when V S becomes larger than V REF1 , it is determined that feedback control is possible, and a feedback control start signal is generated. Similarly, in the case of a "lean" mixture, it is determined that feedback control is possible when V S becomes lower than V REF2 .
O2センサの温度が十分高い場合には帰還制御
を続け、上述の基準電位VREF1，VREF2の一方を空
燃比比較の基準信号として端子電位VSの値を監
視する。別の基準電位VREF3を基準信号として設
定することが可能である。 If the temperature of the O 2 sensor is sufficiently high, feedback control is continued, and the value of the terminal potential V S is monitored using one of the reference potentials V REF1 and V REF2 as a reference signal for air-fuel ratio comparison. It is possible to set another reference potential V REF3 as the reference signal.
機関をアイドリング状態で放置した場合等では
O2センサの温度が次第に低下し、内部抵抗ρが
増加して端子電位VSの特性は部分Ｂから部分Ａ
に移る。従つて端子電位VSが基準電位VREF1，
VREF2の間に所定時間存在することを判別して帰
還制御を停止することができる。端子電位と基準
電位との比較はソフトウエアプログラムによつて
CPU４が行う。CPU４が行う上述の比較機能、
帰還制御開始点の弁別、“濃”“薄”混合気の弁別
は極めて容易に作成され、アナログ制御システム
で必要とする複雑な回路は省略される。 If the engine is left idling, etc.
The temperature of the O 2 sensor gradually decreases, the internal resistance ρ increases, and the characteristics of the terminal potential V S change from part B to part A.
Move to. Therefore, the terminal potential V S is the reference potential V REF1 ,
Feedback control can be stopped by determining that a predetermined period of time exists between V REF2 . Comparison of terminal potential and reference potential is performed by a software program.
Performed by CPU4. The above comparison function performed by CPU4,
Discrimination of the starting point of feedback control and discrimination of "rich" and "lean" mixtures can be made very easily, and complex circuits required in analog control systems can be omitted.
下限基準電位VREF2の値は通常は一定値である。
第４図に示す通り、“濃”状態で帰還制御を開始
した場合にVS＞VREF1となり、空燃比を“薄”混
合気側に制御する作動を行う。この制御によつて
“薄”混合気となつた状態をO2センサが検知し端
子電位VSは第４図のＣ点において“薄”信号を
出す。帰還制御開始からO2センサが“薄”信号
を出すまでに比較的長時間を必要とし、一時的に
機関は過薄混合気運転を続け、機関回転数の低下
又は停止を生ずる。 The value of the lower limit reference potential V REF2 is usually a constant value.
As shown in FIG. 4, when feedback control is started in a "rich" state, V S >V REF1 , and an operation is performed to control the air-fuel ratio to a "lean" mixture side. As a result of this control, the O 2 sensor detects a "lean" air-fuel mixture, and the terminal potential V S outputs a "lean" signal at point C in FIG. It takes a relatively long time from the start of feedback control until the O 2 sensor issues a "lean" signal, and the engine temporarily continues to operate with a lean mixture, resulting in a drop in engine speed or a stoppage.
これを防ぐために、第４図に示す実施例におい
ては、“濃”混合気による帰還制御開始の時に下
限基準電位VREF2を高い電位VREF2′に移動させ、
その後に所定の割合で元の値まで低下させる。こ
れによつて、端子電位VSはＣ点よりも早くＤ点
で見かけの下限値に達し、ここで“薄”信号が生
ずるため、機関の過薄運転時間は短縮され、回転
低下を防止する。 In order to prevent this, in the embodiment shown in FIG. 4, the lower limit reference potential V REF2 is moved to a higher potential V REF2 ' when starting feedback control with a "rich" mixture.
Thereafter, it is lowered to the original value at a predetermined rate. As a result, the terminal potential V S reaches the apparent lower limit value at point D earlier than at point C, and a "lean" signal is generated here, which shortens the engine's running time and prevents a drop in rotation. .
なお、第４図Ｄ点での端子電圧VSの下限値の
判定に当つては、判定出力を安定させるため、通
常行なわれるように基準電位にヒステリシスを持
たせている。 Note that when determining the lower limit value of the terminal voltage V S at point D in FIG. 4, the reference potential is given hysteresis, as is normally done, in order to stabilize the determination output.
上述によつて明らかにされた通り、本発明によ
つて極めて簡単な回路と容易に作成できる処理プ
ログラムとによつて所望の空燃比帰還制御を容易
に精度良く行うことができる。 As clarified above, according to the present invention, desired air-fuel ratio feedback control can be easily and accurately performed using an extremely simple circuit and a processing program that can be easily created.
第１図は本発明空燃比帰還制御装置を適用する
内燃機関制御装置のブロツク線図、第２図は本発
明によるO2センサ信号処理回路図、第３図は第
２図のセンサ出力端子電位の変化を示す図、第４
図は“濃”信号による帰還制御開始時の基準電位
増加の実施例を示す図、第５図は本発明の機能を
示すブロツク図である。
１…センサ群、２，２１…インターフエース、
３…アクチユエータ群、４…中央演算処理装置
（CPU）、５…電流流しこみ回路、６…増巾器、
１１…O2センサ、１１１…内部抵抗、１１２…
起電力。
Fig. 1 is a block diagram of an internal combustion engine control device to which the air-fuel ratio feedback control device of the present invention is applied, Fig. 2 is an O 2 sensor signal processing circuit diagram of the present invention, and Fig. 3 is the sensor output terminal potential of Fig. 2. Figure 4 showing changes in
The figure shows an example of increasing the reference potential at the start of feedback control using a "dark" signal, and FIG. 5 is a block diagram showing the functions of the present invention. 1...Sensor group, 2, 21...Interface,
3... actuator group, 4... central processing unit (CPU), 5... current injecting circuit, 6... amplifier,
11...O 2 sensor, 111...internal resistance, 112...
Electromotive force.
Claims (1)
算機と、機関の排気管に取付けられ排気ガス内の
酸素濃度を検知する排気センサとを有し、排気セ
ンサの出力信号を比較基準電位と比較して、排気
センサの出力信号レベルが帰還制御可能状態にあ
ると判定された時、排気センサ出力信号により上
記デジタル計算機の演算結果を修正して空燃比を
所望値に帰還制御する空燃比帰還制御装置におい
て、所定の電圧を抵抗により分圧し、上記分圧電
位点から抵抗を介して上記排気センサとの接続点
に電流を流しこむ電流流し込み回路と、上記接続
点からの排気センサ出力信号を増幅しＡ／Ｄ変換
してマイクロプロセサに入力する入力回路とを備
え、かつ、上記マイクロプロセツサの機能とし
て、第１の比較基準電位を設定する第１比較基準
電位設定手段と、該第１の比較基準電位より低い
第２の比較基準電位を設定する第２比較基準電位
設定手段と、排気センサ出力信号レベルが上記第
１、第２の比較基準電位の間から逸脱した時に帰
還制御可能状態と判定して帰還制御を開始させ、
排気センサ出力信号レベルが上記第１、第２の比
較基準レベルの間に所定時間存在することを判別
して帰還制御を停止させる判定手段と、排気セン
サ出力信号レベルが上記第１の比較基準電位を超
えて帰還制御が開始された時に上記第２比較基準
電位を初期設定値よりも上昇した他の設定値に移
行させ、その後所定の割合で上記設定値を下降さ
せて初期設定値または他の設定値に向つて変化さ
せる比較基準電位変更手段とを備えたことを特徴
とする内燃機関の空燃比帰還制御装置。1 It has a digital computer that calculates the amount of fuel supplied to the internal combustion engine, and an exhaust sensor that is attached to the exhaust pipe of the engine and detects the oxygen concentration in the exhaust gas, and compares the output signal of the exhaust sensor with a comparison reference potential. , an air-fuel ratio feedback control device that feedback-controls the air-fuel ratio to a desired value by correcting the calculation result of the digital computer based on the exhaust sensor output signal when it is determined that the output signal level of the exhaust sensor is in a feedback control possible state; , a current inflow circuit that divides a predetermined voltage by a resistor and flows a current from the divided potential point to a connection point with the exhaust sensor via the resistor; and A, which amplifies the exhaust sensor output signal from the connection point. a first comparison reference potential setting means for setting a first comparison reference potential as a function of the microprocessor; a second comparison reference potential setting means for setting a second comparison reference potential lower than the potential, and determining that feedback control is possible when the exhaust sensor output signal level deviates from between the first and second comparison reference potentials. to start feedback control,
determining means for determining that the exhaust sensor output signal level exists between the first and second comparison reference levels for a predetermined period of time and stopping the feedback control; When feedback control is started by exceeding the initial setting value, the second comparison reference potential is shifted to another set value that is higher than the initial set value, and then the set value is lowered at a predetermined rate to change to the initial set value or another set value. 1. An air-fuel ratio feedback control device for an internal combustion engine, comprising: comparison reference potential changing means for changing the potential toward a set value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4301179A JPS55137334A (en) | 1979-04-11 | 1979-04-11 | Air-fuel return controller for internal cumbustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4301179A JPS55137334A (en) | 1979-04-11 | 1979-04-11 | Air-fuel return controller for internal cumbustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55137334A JPS55137334A (en) | 1980-10-27 |
| JPS638293B2 true JPS638293B2 (en) | 1988-02-22 |
Family
ID=12652035
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4301179A Granted JPS55137334A (en) | 1979-04-11 | 1979-04-11 | Air-fuel return controller for internal cumbustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55137334A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3945284A1 (en) | 2020-07-29 | 2022-02-02 | Topcon Corporation | Leveling base, surveying instrument and surveying system |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5713245A (en) * | 1980-06-30 | 1982-01-23 | Toyota Motor Corp | Method of controlling air fuel ratio of internal combustion engine |
| JPS58217733A (en) * | 1982-06-10 | 1983-12-17 | Matsushita Electric Ind Co Ltd | Fuel injection control method of internal-combustion method |
| JPS6035148A (en) * | 1983-08-05 | 1985-02-22 | Nippon Denso Co Ltd | Air-fuel ratio control device |
| JPS6045749A (en) * | 1983-08-22 | 1985-03-12 | Japan Electronic Control Syst Co Ltd | Air-fuel ratio learning controller of electronic fuel injection type internal-combustion engine |
| WO2004003536A1 (en) | 2002-06-27 | 2004-01-08 | National Institute Of Advanced Industrial Science And Technology | Resistance type oxygen sensor and oxygen sensor device using it and air/fuel ratio control system |
| JP4625930B2 (en) | 2004-10-19 | 2011-02-02 | 独立行政法人産業技術総合研究所 | Resistive oxygen sensor and air-fuel ratio control system using it |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5294929A (en) * | 1976-02-06 | 1977-08-10 | Nissan Motor Co Ltd | Digital system air-fuel ratio control device |
| JPS52135925A (en) * | 1976-05-10 | 1977-11-14 | Nissan Motor Co Ltd | Air fuel ratio control equipment |
| JPS5340133A (en) * | 1976-09-23 | 1978-04-12 | Nippon Denso Co Ltd | Fuel-air ratio feedback control system |
-
1979
- 1979-04-11 JP JP4301179A patent/JPS55137334A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5294929A (en) * | 1976-02-06 | 1977-08-10 | Nissan Motor Co Ltd | Digital system air-fuel ratio control device |
| JPS52135925A (en) * | 1976-05-10 | 1977-11-14 | Nissan Motor Co Ltd | Air fuel ratio control equipment |
| JPS5340133A (en) * | 1976-09-23 | 1978-04-12 | Nippon Denso Co Ltd | Fuel-air ratio feedback control system |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3945284A1 (en) | 2020-07-29 | 2022-02-02 | Topcon Corporation | Leveling base, surveying instrument and surveying system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55137334A (en) | 1980-10-27 |
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