JPH10300720A - Exhaust constituent measuring instrument and engine air/fuel ratio control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expand the controllability of the air/fuel ratio of, for example, an engine to a high-speed region by performing the bi-directional negative feedback control of the oxygen ion current of a standard cell and the detection of an oxygen ion current sequentially by time-sharing. SOLUTION: In an oxygen shading cell 1, a standard cell 12 and a detection cell 13 have platinum electrodes 15, 16, and 20 that oppose one another while sandwiching a zorconia solid electrolyte 14. The electromotive force of the standard cell 12, a bidirectional negative feedback current for making constant the electromotive force, and an oxygen ion current that is correlated to an air/fuel ratio signal are inputted to a microprocessor 31. The bi-directioinal negative feedback control of the oxygen ion current and the detection of the oxygen ion current are performed sequentially by time-sharing. The distribution processing of the proportional distribution, integration distribution, and differential distribution of the amount of negative feedback is performed by a momentary value that is obtained by the time-sharing, thus reducing the transition response delay for detecting the air/fuel ratio and improving the air/fuel ratio control accuracy of a mixed air and hence optimizing the exhaust, fuel consumption, and output due to an operation condition change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an exhaust gas component measuring device used for air-fuel ratio control of an engine and an engine air-fuel ratio control system using the same.

[0002]

2. Description of the Related Art Conventionally, it is known to increase the speed by inserting a phase correction circuit including a capacitor C and a resistor R into a negative feedback loop for keeping an electromotive force constant in an analog circuit.

Japanese Patent Application Laid-Open No. 4-204370 discloses a drive circuit for an air-fuel ratio sensor which aims at controlling the voltage applied to the pump cell to prevent blackening of zirconia forming the pump cell. . That is, this publication discloses a means for flowing a predetermined current through an electromotive cell, and a method for controlling the voltage of the electromotive cell to a predetermined value near the voltage indicated by the voltage of the electromotive cell when the air-fuel ratio of the diffusion chamber is the stoichiometric air-fuel ratio. Pump current control means for controlling the direction and magnitude of the current flowing through the pump cell to obtain a control voltage value, signal output means for outputting a signal corresponding to the current value flowing through the pump cell, and voltage applied to the pump cell And a control voltage changing means for changing a predetermined control voltage value of the electromotive force cell when an absolute value of the voltage exceeds a predetermined voltage. ing.

[0004]

In order to improve the fuel efficiency, exhaust performance and operability of the engine, it is necessary to accelerate the physicochemical response of the exhaust component measuring device including the exhaust component sensor.

According to the present invention, the physicochemical response in the case of using an oxygen concentration cell (cell) having a diffusion control function is increased, that is, the transient response speed is increased, and the air-fuel ratio in combustion equipment such as an engine is increased. The purpose is to extend the controllability of the system to a higher speed range. By extending to the high-speed range, the fuel ratio, exhaust performance, and drivability of the combustion equipment can be improved.

[0006]

According to the present invention, there is provided an oxygen concentration cell (cell) comprising at least a pair of platinum-based electrodes opposed to each other across a zirconia solid electrolyte, and the cell is connected to a detection electrode in the exhaust gas. A detection cell coated with a member that controls the diffusion of the exhaust component, a reference cell in an atmosphere containing oxygen as a reference and outputting an electromotive force corresponding to the oxygen partial pressure, and the cell In an exhaust gas component measuring apparatus comprising an electronic circuit for driving and processing the signal, the electronic circuit detects (measures) an electromotive force of the reference cell, and bidirectional negative feedback of an oxygen ion current for making the electromotive force constant. The control and the detection (measurement) of the oxygen ion current having a correlation with the air-fuel ratio signal are sequentially performed in a time-division manner, and the instantaneous values obtained in the time-division are used to calculate the proportional component, the integral component, and the derivative component of the negative feedback amount. Arrangement (Including the ingredients is 0)
Provided is an exhaust component measurement device characterized by processing.

[0007] Preferably, the time-division frequency is at least one digit earlier than the corner frequency for quick response.

Preferably, the proportional component of the negative feedback amount is:
The integral unit 1 (for example, 20 mV) determined by the resolution of the difference E ₁ −E ₀ between the reference power E ₁ and the feedback electromotive force E _0.
Multiply by 5 and add.

According to the present invention, the differential component of the negative feedback amount is a difference between the previous deviation and the present deviation when the reference power E ₁ , the feedback electromotive force E ₀ , and the deviation value are E ₁ −E _0. (E ₁ −E ₀ )
_n-1 - to provide an exhaust component measuring apparatus characterized by adding by multiplying the (E ₁ -E ₀₎ coefficient of 0.1 to 4.0 to _n.

Preferably, the integral component of the negative feedback amount is
When the reference power E ₁ , the feedback electromotive force E ₀ , and the deviation value are E ₁ −E ₀ , the coefficient is 0.02 to 0.6 in the minimum unit e (for example, 20 mV) determined from the previous deviation or its resolution.
Is multiplied by a minimum unit e (for example, 20 mV) determined by the current deviation or its resolution and multiplied by a coefficient of 0.02 to 0.6.

The present invention has an oxygen concentration cell (cell) composed of at least a pair of platinum-based electrodes opposed to each other with a zirconia solid electrolyte body interposed therebetween, and the cell prevents diffusion of exhaust components to a detection electrode in exhaust gas. A detection cell covered with a rate-limiting member, a reference cell in an atmosphere containing oxygen as a reference and outputting an electromotive force corresponding to the oxygen partial pressure, and driving the cell, In an exhaust gas component measuring device comprising an electronic circuit to be processed, detection of an electromotive force of the cell, bidirectional negative feedback control of an oxygen ion current for making the electromotive force constant, and detection of an oxygen ion current are sequentially performed by time division. A negative feedback amount for correcting a delay including a diffusion delay in the detection cell and a catalyst reaction delay component of the electrode by using an instantaneous value obtained by time division. To provide a device.

Preferably, the proportional component is a reference power E
It is determined based on the difference E ₁ −E ₀ between ₁ and the feedback electromotive force E ₀ .

The present invention has an oxygen concentration cell (cell) composed of at least a pair of platinum-based electrodes opposed to each other with a zirconia solid electrolyte body interposed therebetween, and the cell prevents diffusion of exhaust components to a detection electrode in exhaust gas. A detection cell covered with a rate-limiting member, a reference cell in an atmosphere containing oxygen as a reference and outputting an electromotive force corresponding to the oxygen partial pressure, and driving the cell, A device for measuring the partial pressure of oxygen comprising an electronic circuit to be processed, one of which is disposed in an intake pipe to an engine, and detects the electromotive force of the cell, and detects the electromotive force. The bidirectional negative feedback control of the oxygen ion current to be constant and the detection of the oxygen ion current are sequentially performed by time division, and the amount of oxygen in the intake air is determined by determining the negative feedback control amount using the instantaneous value obtained by time division. Request An intake air-fuel ratio measurement device, one of which is an exhaust air-fuel ratio measurement device configured to measure an exhaust air-fuel ratio of an exhaust pipe of an engine and configured similarly to the intake air-fuel ratio measurement device, and Is an exhaust component measuring device that is installed downstream of the catalytic converter of the engine and measures the exhaust component there, and is configured similarly to the intake air-fuel ratio measuring device. An output signal from these measuring devices is output to the engine control device. And performs engine air-fuel ratio control to provide an engine air-fuel ratio control system.

According to the present invention, the electromotive force of the reference cell is detected, the bidirectional negative feedback control of the oxygen ion current for making the electromotive force constant is performed, and the oxygen ion current of the detection cell is detected.
In the method of measuring an exhaust or intake component, when an engine is started, an electromotive force is detected to determine that the value has reached a predetermined value equal to or more than the predetermined value, and a negative feedback is made within 10 seconds after the determination. There is provided a method for measuring an exhaust or intake component, characterized in that additional control is performed by a current Ip.

The present invention detects the electromotive force of the reference cell, performs bidirectional negative feedback control of the oxygen ion current to make the electromotive force constant, and detects the oxygen ion current of the detection cell.
In a method of measuring an exhaust or intake component, a response frequency of a negative feedback amount when a sine wave disturbance is applied to the electromotive force is maintained at a level of 0.1 Hz or less for both gain and phase delay over at least up to 20 Hz. Provided is a method for measuring an exhaust or intake component, which is characterized by being formed.

The operation obtained by time-dividing the oxygen ion current signal of the constant electromotive force negative feedback control and digitally PID-correcting the physicochemical response delay of the sensor is as follows.

1: The transient response delay of the air-fuel ratio detection is reduced,
Since the air-fuel ratio control accuracy of the air-fuel mixture can be improved, the optimization of exhaust, fuel consumption, and output due to changes in operating conditions can be expressed with high-speed response.

2: Regardless of the combination of various structures, dimensions and materials of the diffusion-controlled density cell, the cell can be operated by one general-purpose circuit under the optimum driving conditions.

3: In the analog system, where two gray cells for reference and detection, which are independently and continuously controlled, are required, a single gray cell with a diffusion control function can make up for it. The basic structure can be made compact and the cost can be reduced.

The technical scope of the present invention is not limited to the matters described in the claims, but extends to matters equivalent to or easily deduced therefrom.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, an oxygen concentration cell (cell) 11
Consists of a reference cell 12 and a detection cell 13. Each cell has a pair of platinum-based electrodes 15, 16 and 15, 20 opposed to each other with a zirconia solid electrolyte member 14 interposed therebetween. The electrodes 15, 16 are diffusion-controlling members 1 for controlling diffusion of exhaust components.
7, 18 are coated. In the figure, the diffusion control hole 19 is shown.
Is shown for understanding.

The electrode 16 of the reference cell 12 is provided with a line 22 connected to a negative feedback amplifier 21. A reference voltage (reference electromotive force) is applied from the reference voltage source E23 to the negative feedback amplifier 21, and the output is connected to the electrode 17 of the detection cell 11 via the circuit 24 and the oxygen ion current detection resistor 25 provided in the middle. It is. A constant current source 27 is connected between the electrode 18 and the electrode 15 via a circuit 26 and has a constant current i.
p flows to the negative feedback amplifier 21. The circuit 26 and the reference voltage source 23 are grounded 73 and 74, respectively.

The embodiment shown in FIG. 2 is basically the same as that shown in FIG. 2 except that a pair of platinum-based electrodes 15 'and 16' opposed to each other with a zirconia solid and an electrolyte body 14 interposed therebetween is used.
5 'and 16' are covered with diffusion-controlling members 17 'and 18'. An air introduction passage 101 is formed of a rate-controlling member 18 ′ in the reference electrode 16 ′ so as to communicate with the atmosphere, thereby forming an oxygen concentration cell (cell). It will be understood that the apparatus body is more compact than the example of FIG.

The microprocessor (CPU) 31 includes:
An electromotive force of the reference cell 16, a bidirectional negative feedback current Ip for making the electromotive force constant, and an oxygen ion current having a correlation with the air-fuel ratio signal are input via the detection circuits 32, 33, and 34, respectively. Detection circuits 32, 33, 34 and circuit 27
Are provided with switches 35, 36, 37 and 38, respectively.

In FIG. 3, the sensor control section 41 of the microprocessor comprises an electronic circuit of a sensor control circuit 42 and an output circuit 44. 43 is an activation judging circuit.
The sensor control circuit 42 includes a negative feedback current Ip driving unit 45 and a PID control unit 47. 46 is a Vp limiter unit. The negative feedback current Ip driving section 45 gives an output of Ip to the Ip cell (detection cell) 13 to perform bidirectional negative feedback control of the oxygen ion current. The constant Vs PID control unit 47 controls the amount of the negative feedback current Ip so that the feedback electromotive force Vs of the feedback electromotive force Vs cell (reference cell) 12 becomes constant. The control amount is the negative feedback current Ip. The voltage is supplied to the Vs cell 12 as the driving unit 45 and the feedback electromotive force. As described above, the sensor control circuit 42 performs PID control of the negative feedback current Ip so that Vs = 450 mV is constant.

The output circuit 44 converts the amount of the negative feedback current Ip into a voltage Vout 50 and outputs it. This output is used for air-fuel ratio control.

The details of the circuit will be described.

Ic circuit 52: The Ic circuit 52 provided in the sensor control circuit 42 is for flowing a small forward current (Ic) to the Vs cell in order to constantly fill the oxygen reference chamber in the Vs cell with oxygen. It is.

The direction of the oxygen ion current differs between rich and lean air-fuel ratios. Therefore, to convert the voltage to a voltage by an operational amplifier and output the voltage, for example, a bias of Vcent = 4 V is applied, and the oxygen ion current becomes −10 mA, 0 m
A, + 10mA, 1.0V, 4.0V,
As 7.0 V, all are output with positive polarity voltage. In general, the output voltage range can be output in the widest range when a half bias of the supply voltage of the operational amplifier is applied.

Negative feedback current Ip driver 45: This circuit controls the negative feedback current Ip so that Vcent = 4V is constant.

Regarding the measurement of the electromotive force of the Vs cell, the bidirectional negative feedback control of the oxygen ion current for making the electromotive force constant, and the measurement of the oxygen ion current having a correlation with the air-fuel ratio signal, these control amounts are time-divided. In addition to performing the measurement and control sequentially, and using the instantaneous value obtained by time division, the distribution of the proportional component, integral component, and differential component of the negative feedback current is optimized, thereby controlling the diffusion. The response delay of gas diffusion in the coated Ip cell and the response delay of oxidation / reduction of catalytic electrode and gas ion substitution reaction are made faster. Here, the integral component or the derivative component may be distributed to zero. By the sequential processing by time division, it is possible to arbitrarily set the response and the gain, and it is possible to accurately cope with a high-speed engine region.

Transfer relationship: The relationship between ΔVs and Ip is a transfer function shown in FIGS. 5 and 6, and the capacitances of the resistor R and the capacitor C are determined so as to obtain this characteristic.

The first stage is a low-pass filter LPF,
The second stage is a PID circuit.

Although the figure shows the case where the frequency is 0.1 Hz or more, the influence of the integral value appears at a lower frequency, and the time constant of the integral term is about 4.7 sec.

Each stage sum represents a transfer function of the entire circuit. The communication relationship is determined by evaluating the following items.

The phase delay of the sensor becomes maximum around 30 Hz, and the phase of the circuit is made to advance most at 30 Hz in order to correct this.

Fast convergence during step response.

Reduce the noise appearing in Ip.

No oscillation occurs under each operating condition of the engine.

Vp limiter section 46: This limiter is
This is a voltage limiter for preventing black ring of the Ip cell.

Vp is ± 2 V or more (Vp +> 6 V or V
When (p + <2V), each comparator circuit shifts 3.55V of the PID circuit in a direction to reduce Ip. This will shift the 450 mV control point to Vs in the Z-curve (changing the atmosphere in the sensor measurement chamber), which will also reduce the electromotive force of the Ip cell.
In other words, when the electromotive force of the Ip cell decreases to 2 V or less, it does not change to Ip. Otherwise, Ip is reduced to Vp.
p is suppressed to 2 V or less.

Activity determination circuit 43: In this circuit, the activity of the sensor is determined based on the voltage Vs. Before activation, the output of this circuit is used to ground the outputs of the PID circuit and the Ip drive circuit with transistors, so that Ip does not flow. During this time, Vcent is 4 V or less. Immediately after the power is turned on, the sensor chip temperature is low and the internal resistance of the Vs cell is large, so that the voltage applied to the Vs cell is about 3 V. After that, the Vs resistance decreases as the chip temperature increases, so that the Vs also decreases. In this circuit, Vs
It is judged to be active at <1.1 V. When Vs falls below this value, charging of the capacitor is started, and after 10 seconds, control of Ip is permitted.

The voltage judgment and the delay timer when the engine control unit ECU is mounted are processed by the CPU.

Output circuit 44: A circuit for converting the negative feedback current Ip into a voltage (Ip → Vout), differentially amplifies the voltage drop of the Ip detection resistor, and outputs the result via a filter.

The variation correction of the sensor is performed by the connected correction resistor 51. This correction resistor is inserted into the connector of the sensor.

It should be noted that Ip is detected by connecting A / A at both ends of the detection resistor.
D may be input.

Heater control circuit 61: The heater application voltage is duty-controlled so as to keep the sensor chip temperature at about 800 ° C. Thus, the power applied to the heater 65 is equivalent to 10.5V. When the ECU is mounted, PWM control by the CPU is preferable.

The reference oxygen partial pressure is obtained by ionizing oxygen in the exhaust gas and pumping the oxygen.
It is generated by storing it in a reference cell provided independently of a detection cell covered with a member that controls diffusion of exhaust components (in the case of FIG. 1). Alternatively, the reference oxygen partial pressure uses oxygen in the atmosphere and stores it in a reference cell provided independently of the detection cell on the exhaust side which is covered with a member that controls the diffusion of exhaust components. (Fig. 2
in the case of).

The frequency of the time division is a frequency which is at least approximately one digit earlier than the corner frequency at which the response speed of the negative feedback loop is to be increased.

[0051] Figure 4, reference electromotive force E ₁ and deviations E ₁ -E ₀ of the feedback electromotive force E ₀ shows the relationship between time and. Reference electromotive force E
₁ gradually increases, and the deviation E ₁ −E ₀ changes from − to +.

FIG. 5 shows the relationship between the response frequency of the bidirectional negative feedback current Ip and the gain (db), and FIG. 6 shows the response frequency of the bidirectional negative feedback current Ip and the phase delay (de) of the sensor.
g), and as can be seen from the figure, the present invention resides in a method for measuring exhaust or intake components, characterized in that the response frequency of bidirectional negative feedback current is formed in a mountain shape up to 1 kHz. You can see that. In particular, the maximum value is shown around 10 Hz, indicating that the response can be performed up to 1 kHz. In this figure, the dotted line shows the change ΔIp of the bidirectional negative feedback current Ip when the present invention is not applied, and the solid line shows the change ΔIp of the bidirectional negative feedback current Ip when the present invention is applied.

In these cases, the negative feedback amount of the PID does not give any selectivity depending on the frequency band, and is also actually measured data when the proportional coefficient of each PID is uniformly set to 1.0. Therefore, if the selectivity according to the frequency band is given, more accurate control can be performed. The proportional component of the amount of the negative feedback current Ip is the minimum unit e determined by the resolution of the difference E ₁ −E ₀ between the reference electromotive force E ₁ and the feedback electromotive force E ₀ , for example, 20 m.
V is multiplied by integer coefficients 1 to 5 and added.

The differential component of the amount of the negative feedback current Ip is the difference between the previous deviation and the current deviation with respect to the time division value of the difference E ₁ −E ₀ between the reference electromotive force E ₁ and the feedback electromotive force E _0. (E ₁ −E ₀ )
_{n-1 - (E 1 -E} 0) desirable _n is set to sum by multiplying a factor 0.1 to 4.0.

The integral component of the amount of the negative feedback current Ip is determined from the previous deviation or its resolution with respect to the time division value of the difference E ₁ −E ₀ between the reference electromotive force E ₁ and the feedback electromotive force E _0. In the smallest unit, for example, 20 mV, preferably 0.02
A value obtained by multiplying by 0.5 and accumulatively adding the minimum unit e determined by the current deviation or its resolution, for example, 20 mV
Preferably, the coefficients are multiplied by 0.02 to 0.6 and added.

An overall control system for the engine air-fuel ratio using the exhaust gas component measuring device will be described with reference to FIG.

The air cleaner 7 is provided on the intake side of the engine 71.
2 and the intake pipe 73 are connected, and a purge control valve 74 and an EGR control valve 75 are attached to the intake pipe 73. An exhaust pipe 76 and a catalytic converter 77 are provided on the exhaust side of the engine 71.
And a muffler 78 are attached. The intake pipe 73 is provided with an intake air-fuel ratio sensor 79, that is, an oxygen partial pressure measurement device that detects the amount of oxygen in the intake air. The configuration has the same configuration as that of the above-described exhaust gas component measuring device, and it is in the same range in terms of the configuration whether it is called exhaust or intake. An exhaust air-fuel ratio sensor 80, that is, an exhaust gas component measuring device is attached to an exhaust pipe 76 between the engine 71 and the catalytic converter 77, and a catalyst diagnostic sensor 81, that is, a catalytic converter 77 is output to the exhaust pipe 76 downstream of the exhaust pipe. A device is installed for measuring the oxygen in the exhaust gas or the oxygen partial pressure of the pre-existing components. The configuration has the same configuration as that of the above-described exhaust gas component measuring device, and is in the same range in terms of measurement whether it is called exhaust gas or oxygen or partial pressure of natural components.

The outputs of the intake air-fuel ratio sensor 79, the exhaust air-fuel ratio sensor 80, and the catalyst diagnosis sensor 81 are input to an engine control unit ECU 82, which outputs a control amount for engine air-fuel ratio control or a signal for catalyst diagnosis. .

An example of the use of the exhaust gas component measuring device configured as described above will be described with reference to FIG. The drawing shows a general engine system in which an air cleaner 72 and a purge control valve 74 / EGR control 75 are installed in an intake pipe 73 of an engine 71, and a catalytic converter 77 and a muffler 78 are installed in an exhaust pipe 76. I have. In such a system, an intake air-fuel ratio sensor 79 is provided in the intake pipe 73, and a catalyst diagnostic sensor 81 is provided in the exhaust pipe 76 between the engine 71 and the catalytic converter 77. The exhaust gas component measuring device described above is used for these sensors 79, 80, 81. Reference numeral 79 denotes an intake air-fuel ratio sensor which is used in relation to engine exhaust and is shown as an example of an exhaust component measuring device. These sensors 79, 80, 81 are connected to an engine control device 82, and the detection values are input. The engine control device 82 calculates an air-fuel ratio control output value using these input values,
Calculate the catalyst diagnosis output value. As described above, since the response delay of gas diffusion and the response delay of oxidation / reduction of the catalytic electrode and gas / ion substitution reaction in the detection cell covered with the diffusion rate-controlling member can be made faster, the air-fuel ratio control is performed. In addition, the speed of catalyst diagnosis can be increased.

[0060]

The measurement of the electromotive force of the reference cell, the bidirectional negative feedback control of the oxygen ion current for making the electromotive force constant, and the measurement of the oxygen ion current having a correlation with the air-fuel ratio signal are sequentially performed in a time division manner. Controlling the amount of negative feedback current using the instantaneous value obtained by time-sharing to control the gas diffusion response in the detection cell covered with a member that controls the diffusion, oxidation / reduction of the catalytic electrode, and gas ion The response delay of the substitution reaction can be made faster.

Further, by using such a measuring device, the correlation between the air-fuel ratio signal and the oxygen ion current measurement in the engine control unit ECU can be accurately obtained, and the air-fuel ratio control range can be expanded. Thus, it is possible to provide an integrated control system for the engine air-fuel ratio that can cope with stricter emission regulations.

More specifically, it is possible to further improve the accuracy and expand the control range in the catalyst diagnosis, the evaporative fuel purge control, and the EGR limit control using the vehicle-mounted device. Lean limit /
It is possible to improve the accuracy of the stoichiometric switching control and expand the control range, thereby providing a system aiming at improving fuel efficiency.

[Brief description of the drawings]

FIG. 1 is a diagram showing the concept of one embodiment of the present invention.

FIG. 2 is a diagram showing the concept of another embodiment of the present invention.

FIG. 3 is a detailed view of a part of the configuration shown in FIGS. 1 and 2;

FIG. 4 is a diagram showing a relationship between deviation E ₁ −E ₀ and time.

FIG. 5 is a diagram illustrating frequency characteristics of a PID control circuit.

FIG. 6 is a diagram illustrating another frequency characteristic of the PID control circuit.

FIG. 7 is a diagram showing a total control system for an engine air-fuel ratio provided by the present invention.

[Explanation of symbols]

Reference numeral 11: oxygen concentration cell (cell), 12: reference cell (Vs cell) 13: detection cell, (Ip cell), 14: zirconia solid electrolyte, 15: electrode, 16: electrode, 17: diffusion-controlling member, 18: Diffusion controlling member, 20 electrodes, 21 negative feedback amplifier, 23 reference voltage source E, 31 microprocessor (CPU), 41 sensor control unit, 42 sensor control circuit, 43 activation determination circuit, 44 output Circuit, 45
... feedback current Ip drive unit, 47 ... PID control unit, 61 ... heater control and power supply unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naoki Minami 2477 Takaba, Hitachinaka-shi, Ibaraki Pref. Hitachi Car Engineering Co., Ltd.

Claims (10)

[Claims] 1. An oxygen concentration cell (cell) comprising at least a pair of platinum-based electrodes opposed to each other with a zirconia solid electrolyte body interposed therebetween, and the cell controls diffusion of an exhaust component to a detection electrode in the exhaust gas. A detection cell covered with a member, and a reference cell which is in an atmosphere containing oxygen as a reference and outputs an electromotive force corresponding to the oxygen partial pressure, and drives the cell to process the signal. The electronic circuit includes an electronic circuit for detecting (measuring) an electromotive force of the reference cell, bidirectional negative feedback control of an oxygen ion current for making the electromotive force constant, and correlating with an air-fuel ratio signal. The detection (measurement) of the oxygen ion current having the following is sequentially performed in a time-division manner, and the proportional component, the integral component, and the differential component of the negative feedback amount are distributed using the instantaneous values obtained by the time-division (when the component mixture is 0). Ariko And an exhaust gas component measuring apparatus. 2. The exhaust gas component measuring apparatus according to claim 1, wherein the frequency of the time division is at least one digit earlier than a corner frequency for quick response. 3. The minimum unit e according to claim 1, wherein the proportional component of the negative feedback amount is determined by the resolution of a difference E ₁ −E ₀ between the reference power E ₁ and the feedback electromotive force E _0.
(E.g., 20 mV) multiplied by an integer of 1 to 5 and added and set. 4. The differential component of the amount of negative feedback is represented by: a reference power E ₁ , a feedback electromotive force E ₀ , and a deviation value E ₁ −E ₀ .
The difference between the previous deviation and the current deviation (E ₁ −E ₀ ) _n−1 − (E
₁ -E ₀ ) An exhaust gas component measuring apparatus, wherein _n is multiplied by a coefficient of 0.1 to 4.0 and added. 5. The integrated component of the negative feedback amount according to claim 1, wherein the integral component of the negative feedback amount is a deviation amount up to the previous time or a value corresponding to the deviation value when the reference value E ₁ , the feedback electromotive force E ₀ , and the deviation value are E ₁ −E _0. The minimum unit e determined by the resolution (for example, 20
mV) multiplied by a coefficient of 0.02 to 0.6 and cumulatively added, the minimum unit e (for example, 20 mV) determined by the current deviation or its resolution is multiplied by a coefficient of 0.02 to 0.6 and added. An exhaust gas component measuring device characterized by the following. 6. An oxygen concentration cell (cell) comprising at least a pair of platinum-based electrodes opposed to each other with a zirconia solid electrolyte body interposed therebetween, and the cell controls diffusion of exhaust components to a detection electrode in exhaust gas. A detection cell covered with a member, and a reference cell that outputs an electromotive force corresponding to the oxygen partial pressure in an atmosphere containing oxygen as a reference, drives the cell, and processes a signal thereof. In an exhaust gas component measuring device comprising an electronic circuit, detection of an electromotive force of the cell, bidirectional negative feedback control of an oxygen ion current for making the electromotive force constant, and detection of an oxygen ion current are sequentially performed by time division. An exhaust component measuring device, wherein an amount of negative feedback for correcting a delay including a diffusion delay in the detection cell and a catalyst reaction delay component of an electrode is determined using an instantaneous value obtained by the division. 7. The exhaust component measuring device according to claim 6, wherein the proportional component is determined based on a difference E ₁ −E ₀ between the reference power E ₁ and the feedback electromotive force E ₀ . 8. An oxygen concentration battery (cell) comprising at least a pair of platinum-based electrodes opposed to each other with a zirconia solid electrolyte body interposed therebetween, and the cell controls diffusion of an exhaust component to a detection electrode in the exhaust gas. A detection cell covered with a member, and a reference cell that outputs an electromotive force corresponding to the oxygen partial pressure in an atmosphere containing oxygen as a reference, drives the cell, and processes a signal thereof. A device for measuring a partial pressure of oxygen comprising an electronic circuit, one of which is disposed in an intake pipe to an engine, and detects an electromotive force of the cell and keeps the electromotive force constant. The bidirectional negative feedback control of the oxygen ion current and the detection of the oxygen ion current are sequentially performed by time division, and the amount of oxygen in the intake is determined by determining the negative feedback control amount using the instantaneous value obtained by time division. Air fuel One of which measures the exhaust air-fuel ratio of the exhaust pipe of the engine,
An exhaust air-fuel ratio measurement device configured in the same manner as the intake air-fuel ratio measurement device, and one of the exhaust air-fuel ratio measurement devices is installed downstream of a catalytic converter of an engine and measures an exhaust component there. An engine air-fuel ratio control system characterized in that it is configured to input an output signal from these measurement devices to an engine control device and perform engine air-fuel ratio control. 9. An electromotive force of a reference cell is detected, and bidirectional negative feedback control of an oxygen ion current for making the electromotive force constant is performed.
In a method of detecting an oxygen ion current of a detection cell and measuring an exhaust or intake component, detecting an electromotive force at the time of starting an engine, and detecting that the value reaches a predetermined value equal to or more than the predetermined value. A method for measuring an exhaust or intake component, comprising: determining, and performing negative feedback control using a negative feedback current Ip within 10 seconds after the determination. 10. An exhaust or intake component is detected by detecting an electromotive force of a reference cell, performing bidirectional negative feedback control of an oxygen ion current to make the electromotive force constant, and detecting an oxygen ion current of the detection cell. A response frequency of a negative feedback amount when a sine wave disturbance is applied to the electromotive force at least up to 20 kHz,
A method for measuring an exhaust or intake component, wherein a phase delay is maintained at a level of 0.1 Hz or less.