WO2012160651A1 - センサの特性補正装置 - Google Patents
センサの特性補正装置 Download PDFInfo
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- WO2012160651A1 WO2012160651A1 PCT/JP2011/061882 JP2011061882W WO2012160651A1 WO 2012160651 A1 WO2012160651 A1 WO 2012160651A1 JP 2011061882 W JP2011061882 W JP 2011061882W WO 2012160651 A1 WO2012160651 A1 WO 2012160651A1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/04—Introducing corrections for particular operating conditions
- F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
- F02D41/062—Introducing corrections for particular operating conditions for engine starting or warming up for starting
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- 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
- F02D41/1439—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the position of the sensor
- F02D41/1441—Plural sensors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- 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
- F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
- F02D41/1454—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
- F02D41/1456—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio with sensor output signal being linear or quasi-linear with the concentration of oxygen
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/24—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means
- F02D41/2406—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using essentially read only memories
- F02D41/2425—Particular ways of programming the data
- F02D41/2429—Methods of calibrating or learning
- F02D41/2451—Methods of calibrating or learning characterised by what is learned or calibrated
- F02D41/2474—Characteristics of sensors
Definitions
- This invention relates to a sensor characteristic correction apparatus. More specifically, the present invention relates to a characteristic correction apparatus that corrects the characteristics of sensors respectively installed before and after a catalyst disposed in an exhaust path of an internal combustion engine.
- Patent Document 1 discloses a failure detection device for an air-fuel ratio control device having air-fuel ratio sensors respectively disposed before and after the catalyst.
- the failure of the air-fuel ratio sensor installed upstream or the failure of the catalytic converter is determined based on the output difference between the air-fuel ratio sensors before and after the catalyst.
- the output of the downstream air-fuel ratio sensor is corrected based on the reference output, and the output of the upstream air-fuel ratio sensor is corrected using the downstream air-fuel ratio sensor.
- Japanese Unexamined Patent Publication No. 6-280662 Japanese Unexamined Patent Publication No. 2003-041990 Japanese Unexamined Patent Publication No. 2010-007534 Japanese Unexamined Patent Publication No. 2008-057481
- a limit current type air-fuel ratio sensor is installed in front of the catalyst, and an electromotive force type air-fuel ratio sensor is installed after the catalyst.
- an electromotive force type air-fuel ratio sensor is installed after the catalyst.
- an object of the present invention is to solve the above-mentioned problems, and to provide a sensor characteristic correction apparatus improved so as to correct a deviation between sensors for detecting two air-fuel ratios installed before and after the catalyst. It is to provide.
- the present invention is a sensor characteristic correction apparatus, comprising a characteristic detection means, a calculation means, a difference detection means, and a correction means.
- the characteristic detection means detects a characteristic of the first sensor installed upstream of the catalyst in the exhaust path of the internal combustion engine and a characteristic of a second sensor that is an air-fuel sensor installed downstream of the catalyst.
- the calculating means calculates the first air-fuel ratio based on the characteristics of the first sensor, and calculates the second air-fuel ratio based on the characteristics of the second sensor.
- the difference detection means detects a difference between the first characteristic and the second characteristic or a difference between the first air-fuel ratio and the second air-fuel ratio when the internal combustion engine is started and the catalyst is in an inactive state. .
- the correction unit corrects the characteristics of the first sensor and / or the second sensor so that the first air-fuel ratio and the second air-fuel ratio become the same according to the difference.
- the first sensor can be an air-fuel ratio sensor.
- the characteristic detection means detects the respective outputs as the characteristics of the first sensor and the characteristics of the second sensor
- the difference detection means detects the difference between the output of the first sensor and the output of the second sensor.
- the correction unit can be configured to correct the output of the first sensor and / or the second sensor according to the difference.
- the correction unit corrects the output according to the difference in the output, and the response of the first sensor and / or the second sensor. Further, a configuration for further correction may be adopted.
- the first sensor may be an air-fuel ratio sensor
- the characteristic detection unit may detect the responsiveness as the characteristic of the first sensor and the characteristic of the second sensor.
- the difference detecting means detects a difference between the responsiveness of the first sensor and the responsiveness of the second sensor
- the correcting means determines the responsiveness of the first sensor and / or the second sensor according to the difference. It can be corrected.
- the correction means may be configured to correct the characteristics of the first sensor so that the first air-fuel ratio is the same as the second air-fuel ratio, with the characteristics of the second sensor as a reference. .
- the first sensor may be an in-cylinder pressure sensor
- the difference detection means may be configured to detect a difference between the first air-fuel ratio and the second air-fuel ratio.
- the correction means can correct the first air-fuel ratio according to the difference.
- the difference detecting means is configured to detect the first empty in each of the operation states when the internal combustion engine is in the operation state with EGR and in the operation state without EGR. A difference between the fuel ratio and the second air-fuel ratio can be detected.
- the correction means may be configured to calculate a correction amount for the EGR amount in the operation state with EGR by comparing the difference in the operation state with EGR and the difference in the operation state with EGR. .
- the first sensor is an in-cylinder pressure sensor
- the sensor correction device controls the air-fuel ratio of the internal combustion engine to a predetermined rich air-fuel ratio after the internal combustion engine is started and the catalyst is inactive. It can be set as the structure provided with.
- the difference detection means can detect a difference between the first air-fuel ratio and the second air-fuel ratio when the rich air-fuel ratio is controlled.
- the sensor correction device comprises air-fuel ratio control means for controlling the air-fuel ratio of the internal combustion engine to a predetermined rich air-fuel ratio or lean air-fuel ratio after the internal combustion engine is started and the catalyst is inactive. Further, it may be configured to be further provided.
- the difference detecting means detects a difference in characteristics between the first sensor and the second sensor or a difference between the first air-fuel ratio and the second air-fuel ratio when the rich air-fuel ratio or the lean air-fuel ratio is controlled. It can be detected.
- the characteristics of the first and second sensors, or the difference between the air-fuel ratios based on the characteristics of the exhaust gas before and after the catalyst match, Based on this difference, the air-fuel ratio based on both sensors can be corrected so as to match.
- this can be corrected so as to match between the sensors before and after the catalyst. Therefore, it is possible to execute processing such as catalyst deterioration determination with higher accuracy.
- the output characteristics are the same between the two air-fuel ratio sensors based on this detected value.
- Output correction can be performed so that Further, for detecting a difference in output between the two air-fuel ratio sensors when the catalyst is inactive or a difference in responsiveness, the responsiveness between the two air-fuel ratio sensors can be corrected based on this detected value.
- the first air-fuel ratio sensor installed upstream of the catalyst detects high-concentration and high-temperature exhaust gas.
- the second air-fuel ratio sensor installed downstream of the catalyst detects low-concentration and low-temperature exhaust gas. Therefore, the second air-fuel ratio sensor is less likely to deteriorate than the first air-fuel ratio sensor.
- the characteristics of the first air-fuel ratio sensor can be corrected more accurately with respect to those that correct the characteristics of the first air-fuel ratio sensor with reference to the characteristics of the second air-fuel ratio sensor.
- the air-fuel ratio based on the output of the in-cylinder pressure sensor is calculated using a preset calculation coefficient or the like.
- the air-fuel ratio varies depending on the operating state of the internal combustion engine, fuel properties, changes with time, and the like.
- the in-cylinder pressure sensor which is the first sensor is based on the output of the air-fuel ratio sensor downstream of the catalyst by utilizing the state before the catalyst activation.
- the air-fuel ratio based on the can be corrected. Therefore, even when no air-fuel ratio sensor is installed upstream of the catalyst, the air-fuel ratio can be detected with high accuracy by the in-cylinder pressure sensor.
- FIG. 6 is a diagram for explaining the behavior of limit currents of air-fuel ratio sensors before and after the catalyst when the catalyst is inactive after the internal combustion engine 2 is started. It is a figure for demonstrating the relationship of the output of both the air fuel ratio sensors before and behind correction
- Embodiment 2 of this invention It is a flowchart for demonstrating the control routine which a control apparatus performs in Embodiment 2 of this invention. This represents a change in the air-fuel ratio based on the sensor output when the actual air-fuel ratio is changed. It is a figure for demonstrating the routine of control which a control apparatus performs in Embodiment 3 of this invention. It is a figure for demonstrating the relationship between the limiting current of an air fuel ratio sensor, and a response. It is a flowchart for demonstrating the control routine which a control apparatus performs in Embodiment 4 of this invention. It is a schematic diagram for demonstrating the whole structure of the system of Embodiment 5 of this invention.
- FIG. FIG. 1 is a schematic diagram for explaining an overall configuration of a system according to Embodiment 1 of the present invention.
- the system of FIG. 1 is used by being mounted on a vehicle or the like.
- catalysts 6 and 8 are installed in the exhaust path 4 of the internal combustion engine 2.
- An air-fuel ratio sensor 10 (first sensor) is installed upstream of the catalyst 6 in the exhaust path 4.
- An air-fuel ratio sensor 12 (second sensor) is installed downstream of the catalyst 6 in the exhaust path 4 and upstream of the catalyst 8.
- Both air-fuel ratio sensors 10 and 12 are limit current type sensors, and output a limit current (IL) as an output corresponding to the air-fuel ratio of the exhaust gas to be detected.
- IL limit current
- the air-fuel ratio sensor 10 on the upstream side of the catalyst 6 is also referred to as “Fr sensor 10”
- the air-fuel ratio sensor 12 on the downstream side is also referred to as “Rr sensor 12”.
- the control device 14 comprehensively controls the entire system of the internal combustion engine 2.
- Various actuators are connected to the output side of the control device 14, and various sensors such as the air-fuel ratio sensors 10 and 12 are connected to the input side.
- the control device 14 receives the sensor signal, detects the air-fuel ratio of the exhaust gas, the engine speed, and other various information necessary for the operation of the internal combustion engine 2, and operates each actuator according to a predetermined control program.
- the control executed by the control device 14 in this system includes correction of sensor output as a characteristic of the air-fuel ratio sensors 10 and 12.
- the output correction of the air-fuel ratio sensors 10 and 12 is executed after the internal combustion engine 2 is started and the catalyst 6 is inactive.
- FIG. 2 is a diagram for explaining the change in the operating state after the internal combustion engine 2 is started and the change in the air-fuel ratio based on the outputs of the air-fuel ratio sensors 10 and 12.
- FIG. 3 is a diagram for explaining the behavior of the limiting currents of the air-fuel ratio sensors 10 and 12 when the catalyst 6 is inactive after the internal combustion engine 2 is started.
- 2, (a) is the air-fuel ratio (second air-fuel ratio) detected based on the output of the Rr sensor 12
- (b) is the air-fuel ratio (first air-fuel ratio) detected based on the output of the Fr sensor 10.
- (C) represents the temperature of the catalyst 6, and (d) represents the vehicle speed.
- 3A shows the limiting current of the Rr sensor 12
- FIG. 3B shows the limiting current of the Fr sensor 10.
- the catalyst 6 has reached the activation temperature at time t1.
- the output of the Fr sensor 10 changes to the exhaust gas before purification discharged from the internal combustion engine 2 in accordance with the air-fuel ratio.
- the Rr sensor 12 uses the exhaust gas purified after the activation of the catalyst 6 as a detection target. Therefore, the air-fuel ratio based on the output of the Rr sensor 12 stably shows a substantially constant value (a value in the vicinity of the theoretical air-fuel ratio).
- the control device 14 detects the output (limit current) as the characteristics of the Fr sensor 10 and the Rr sensor 12 when the catalyst 6 is inactive after the internal combustion engine 2 is started. When there is a difference between the two, a correction coefficient for correcting the output of the Fr sensor 10 is calculated. Thereafter, the output of the Fr sensor 10 is corrected using this correction coefficient until a new correction coefficient is set.
- FIG. 4 is a diagram for explaining the relationship between the outputs of both sensors 10 and 12 before and after correction according to the first embodiment of the present invention.
- the horizontal axis represents the air-fuel ratio based on the output of the Fr sensor 10
- the vertical axis represents the air-fuel ratio based on the output of the Rr sensor 12.
- (a) compares the air-fuel ratios of both sensors 10 and 12 before correction
- (b) compares the air-fuel ratios after output correction.
- the air-fuel ratio calculated from the output of the Fr sensor 10 is biased toward the rich side with respect to the Rr sensor 12 (see the straight line (a)). Therefore, in the control of the first embodiment, the Rr sensor 12 is used as a reference, and the output characteristic of the Fr sensor 10 is corrected so as to coincide with the output characteristic of the Rr sensor 12. That is, in this example, the output of the Fr sensor 10 is changed to the lean output so that the air-fuel ratio based on the Fr sensor 10 output matches the air-fuel ratio based on the Rr sensor 12 output (see the straight line (b)). A correction coefficient to be corrected is set.
- the limit current of the Fr sensor 10 and the limit current of the Rr sensor 12 are detected when the catalyst 6 is inactive, and the limit current IL_Rr of the Rr sensor 12 and the Fr sensor 10 are detected as in the following equation (1).
- the ratio (limit current ratio) to the limit current IL_Fr is obtained.
- Limit current ratio IL_Rr / IL_Fr (1)
- the detection of the limiting current ratio is repeated and the sample is detected a plurality of times. After the activation of the catalyst 6, the average value of the detected limit current ratio is calculated, and this average value is set as a correction coefficient for the output of the Fr sensor 10.
- the limit currents are compared in consideration of the delay of the exhaust gas transport according to the volume of the exhaust path 4 and the like between the Fr sensor 10 and the Rr sensor 12. That is, the values when the Fr sensor 10 and the Rr sensor are assumed to detect the same exhaust gas are compared.
- the limit current changes on a one-to-one basis with respect to the excess air ratio ( ⁇ ), and increases as the excess air ratio increases.
- ⁇ 1) It is different between a richer case and a leaner case. Therefore, the correction coefficient for the Fr sensor 10 is calculated separately when the air-fuel ratio is richer than the stoichiometric air-fuel ratio and when it is lean.
- the limit current ratio Kl in the case of a lean atmosphere where the limit current IL_Rr of the Rr sensor 12 is greater than 0 and the limit current ratio Kr in the case of a rich atmosphere where IL_Rr is 0 or less are divided and corrected coefficients (average values). ) Is calculated and set.
- the variation of the allowable range due to the initial sensor or deterioration with time is measured in advance, and based on this, the allowable range of the limit current ratio is set as the guard value Kmax.
- Limit current ratios Kl and Kr are used for correction coefficient calculation only when they are smaller than Kmax.
- FIG. 5 is a flowchart for explaining a control routine executed by the control device 14 in the first embodiment of the present invention.
- the routine of FIG. 5 it is first determined whether or not the precondition for calculating the output correction coefficients of the air-fuel ratio sensors 10 and 12 is satisfied (S102). Specific conditions are that the internal combustion engine 2 is instructed to start, the air-fuel ratio sensors 10 and 12 are not in failure and are in an active state, the estimated temperature of the catalyst 6 is lower than a predetermined temperature, etc. It is set in advance and stored in the control device 14.
- the limit current IL_Fr of the Fr sensor 10 and the limit current IL_Rr of the Rr sensor 12 are detected (S104). As described above, here, the limit current for the same exhaust gas is detected in consideration of the delay of the volume between the Fr sensor 10 and the Rr sensor 12.
- the limiting current ratio of the air-fuel ratio sensors 10 and 12 is obtained (S106). Specifically, the ratio between the limit current IL_Rr of the Rr sensor 12 and the limit current IL_Fr of the Fr sensor 10 is calculated according to the above equation (1).
- the temperature of the catalyst 6 is detected (S108).
- the temperature of the catalyst 6 can be detected according to, for example, the output of a temperature sensor (not shown) installed in the vicinity of the catalyst 6.
- the determination is made based on whether or not the temperature of the catalyst 6 has become higher than the activation temperature.
- the activation temperature is a value determined according to the catalyst 6 and is stored in the control device 14 in advance.
- Step S110 if the catalytic activity is not recognized, the process returns to Step S104 again, the limit current IL_Fr of the Fr sensor 10 and the limit current IL_Rr of the Rr sensor 12 are obtained, and the limit current ratio is obtained in Step S106. Thereafter, in accordance with steps S108 to S110, it is determined whether or not catalytic activity is recognized. As described above, until the catalyst activity is recognized in step S110, the process of detecting the limit current ratio in steps S104 to S106 and the determination of the catalyst activity in steps S108 to S110 are repeatedly executed.
- a correction coefficient is calculated (S112).
- the limit current ratio obtained in step S106 is divided into a case where IL_Rr> 0 (lean) and a case where IL_Rr ⁇ 0 (rich), and the limit current ratio in each case is An average value is obtained. Both average values are set as correction coefficients. In this calculation, a limit current ratio larger than the guard value Kmax is set not to be used. Thereafter, the current process ends.
- the set correction coefficient is used as a correction coefficient for correcting the output of the Fr sensor 10 until a new correction coefficient is set.
- the output of the Fr sensor 10 is corrected by using the timing at which the outputs of the air-fuel ratio sensors 10 and 12 before and after the catalyst 6 should essentially coincide. Calculate the coefficient. Therefore, the difference in output characteristics between the two air-fuel ratio sensors 10 and 12 can be corrected, and more precise air-fuel ratio control and catalyst deterioration determination can be executed.
- the case where the output correction for the Fr sensor 10 is calculated based on the output of the Rr sensor 12 has been described. Since the Fr sensor 10 is exposed to high-concentration and high-temperature exhaust gas discharged from the internal combustion engine 2, the influence of poisoning is likely to deteriorate greatly. On the other hand, since the Rr sensor 12 detects a low-concentration and low-temperature gas purified by the catalyst 6, it is considered that the Rr sensor 12 is less likely to cause deterioration than the Fr sensor 10. Therefore, more accurate correction can be performed by detecting the correction coefficient based on the Rr sensor 12.
- the present invention is not limited to the one based on the output of the Rr sensor 12.
- the Fr sensor 10 may be used as a reference.
- the output characteristic deviation between the two air-fuel ratio sensors 10 and 12 can be corrected.
- the average value is distributed, and the correction coefficient for each of the Fr sensor 10 and the Rr sensor 12 is obtained. You can also The same applies to the following embodiments.
- the present invention is not limited to this, and the correction coefficient may be calculated uniformly by detecting the limit current ratio or the limit current difference uniformly over the entire region. The same applies to the following embodiments.
- the limit current is detected a plurality of times and the average value of the limit current ratios is used as the correction coefficient.
- the limit current may be detected once and used for calculating the correction coefficient.
- the correction coefficient is not limited to the limit current ratio, and may be a value calculated according to the difference between the limit currents IL_Rr and IL_Fr, or the difference (difference, ratio, etc.) between the limit currents IL_Rr and IL_Fr. The same applies to the following embodiments.
- FIG. The system of the second embodiment has the same configuration as the system shown in FIG.
- the control device 14 according to the second embodiment of the present invention sets the air-fuel ratio to the air-fuel ratio for calculating the correction coefficient when detecting the limit current of the air-fuel ratio sensors 10 and 12 before the catalyst activation for calculating the correction coefficient. Except for the point of control, the same control as in the first embodiment is performed.
- correction air-fuel ratio several different air-fuel ratios are set in advance as the correction coefficient calculation air-fuel ratio (hereinafter referred to as “correction air-fuel ratio”) and stored in the control device 14. .
- the correction air-fuel ratio is, for example, in the range of 14.0-15.2, which is the actual use range, and is selected and set so that the air-fuel ratio is greatly rich or lean in this range.
- the air-fuel ratio is controlled using one rich air-fuel ratio of the correction air-fuel ratio as the target air-fuel ratio.
- the limit current ratio Kr is detected at this rich air-fuel ratio.
- the limit current ratio Kl or Kr is obtained for each of the other lean or rich air-fuel ratios among the correction air-fuel ratios.
- the limit current ratios Kl and Kr are obtained for all the correction air-fuel ratios set in this way. Further, an average value of each of the limit current ratios Kl and Kr is calculated, and this average value is used as a correction coefficient for the Fr sensor 10.
- FIG. 6 is a flowchart for explaining a control routine executed by the control device 14 in the second embodiment of the present invention.
- the routine of FIG. 6 is the same as the routine of FIG. 5 except that the process of step S202 is performed between steps S102 and S104 and the process of step S204 is performed after step S110.
- the target air-fuel ratio is set to an air-fuel ratio in which the limit current ratio is not detected among the correction air-fuel ratios, and the air-fuel ratio control is executed. (S202).
- a correction coefficient is calculated (S112). Specifically, the correction coefficient is divided into a limit current ratio Kr when the air-fuel ratio is rich and a limit current ratio Kl when the air-fuel ratio is controlled to be lean, and is calculated as an average value of each. Again, a guard value Kmax for the limit current ratio is set, and a limit current ratio larger than this guard value is not used for calculating the correction coefficient.
- the air-fuel ratio is largely controlled in the range from rich to lean. Accordingly, a more appropriate correction coefficient can be calculated using a value when a difference in behavior between the two air-fuel ratio sensors of the Fr sensor 10 and the Rr sensor 12 appears greatly.
- the setting range of the correction air-fuel ratio is not limited to this.
- it is desirable that the air-fuel ratio is swung as much as possible so that the difference in limit current appears more remarkably, and it is desirable that the air-fuel ratio change in the actual use range. Accordingly, it is desirable to set a plurality of correction air-fuel ratios so that the air-fuel ratio is varied as much as possible within the range of air-fuel ratios of 14.1 to 15.1 or 14.0 to 15.2.
- Embodiment 3 The system of the third embodiment has the same configuration as the system of FIG.
- the correction coefficient is calculated for the output (limit current) as the characteristics of the air-fuel ratio sensors 10 and 12
- the characteristics of both sensors 10 and 12 are used.
- a control different from the first and second embodiments is performed for calculating a correction value for a certain response.
- FIG. 7 shows the change of the air-fuel ratio based on the outputs of both sensors 10 and 12 when the air-fuel ratio is changed in a stepwise manner.
- 7A shows the actual air / fuel ratio changed
- FIG. 7B shows the air / fuel ratio based on the output of the Fr sensor 10
- FIG. 7C shows the air / fuel ratio based on the output of the Rr sensor 12.
- the exhaust gas first reaches the Fr sensor 10, and the air-fuel ratio based on the Fr sensor 10 is shown as shown in (b).
- the output gradually increases and finally outputs an output corresponding to the actual air-fuel ratio (hereinafter referred to as “actual air-fuel ratio”).
- the exhaust gas reaches the Rr sensor 12 with a delay corresponding to the volume of the exhaust path 4 and the like.
- the output of the Rr sensor 12 starts to change, gradually increases, and finally outputs an output corresponding to the actual air-fuel ratio.
- the output of the Fr sensor 10 starts to change according to the air-fuel ratio and then changes according to the actual air-fuel ratio. It is considered that there is a difference between the time until the output is started and the time until the output corresponding to the actual air-fuel ratio is started after the output of the Rr sensor 12 starts to change. It is done.
- the time from when the output becomes an output corresponding to 3% of the actual air-fuel ratio until the output corresponding to 63% is obtained.
- Response times T_Fr and T_Rr are detected. Thereafter, a ratio between the response time T_Fr of the Fr sensor 10 and the response time T_Rr of the Rr sensor 12 is detected, and a correction value of the response time is calculated.
- the step change of the air-fuel ratio is changed from rich to lean and from lean to rich between the air-fuel ratios 14.1 to 15.1 or 14.0 to 15.2. In each case, the correction value is obtained.
- FIG. 8 is a diagram for explaining a control routine executed by the control device 14 in the third embodiment of the present invention.
- the air-fuel ratio is controlled to a predetermined rich or lean air-fuel ratio so that the air-fuel ratio changes stepwise (S302).
- the response time T_Fr of the Fr sensor 10 and the response time T_Rr of the Rr sensor 12 are detected (S304). Specifically, the time from when each of the Fr sensor 10 and the Rr sensor 12 issues an output signal corresponding to 3% of the actual air-fuel ratio to the time when the output signal corresponding to 63% is issued is the response time. Detected.
- the temperature of the catalyst 6 is detected (S108), and it is determined whether or not catalytic activity is recognized (S110). If the catalytic activity is not recognized, it is next determined whether or not the detection of the response time is completed for each of the set rich air-fuel ratio and lean air-fuel ratio (S308). When the completion of detection of the response time is not recognized, the process returns to step S302 again, and the control is performed so that the next target air-fuel ratio is set and the air-fuel ratio changes again stepwise. Thereafter, detection of a response time with respect to this step change (S304) and calculation of a difference in response time (S306) are executed.
- the correction value for the response is corrected. Specifically, an average value is calculated for each of the difference in response time between the sensors 10 and 12 when the air-fuel ratio is changed to rich and the difference in response time when the air-fuel ratio is changed to lean. This average value is used as a correction value for the responsiveness of the Fr sensor 10.
- the responsiveness deviation can be corrected.
- the responsiveness that is the characteristic of the air-fuel ratio sensor can be matched, and control such as catalyst deterioration determination can be performed with higher accuracy.
- the correction value for the responsiveness of the Fr sensor 10 is calculated using the Rr sensor 12 as a reference.
- the Fr sensor 10 may be used as a reference.
- the obtained correction values are distributed and both the Fr sensor 10 and the Rr sensor 12 are distributed. The responsiveness can be corrected.
- the time from when the output of each sensor 10, 12 shows a 3% change to the actual air-fuel ratio until the 63% change is completed is detected as the response time.
- the range of the response time in the present invention is not limited to this.
- this range can be set as appropriate, such as when a change of 5% or 10% is indicated, and another value is used as the upper limit value of the response time range instead of 63%.
- the response time is a certain range of change time.
- the time from when the air-fuel ratio is changed to when the output of each sensor 10, 12 shows a value corresponding to the air-fuel ratio may be used as the response time.
- Embodiment 4 The system of the fourth embodiment has the same configuration as the system of FIG. In the fourth embodiment, a correction coefficient for the limit current of the Fr sensor 10 and the Rr sensor 12 is obtained, and a correction value for correcting the responsiveness of both the sensors 10 and 12 is detected according to the limit current. Except for this point, the same control as in the system of the first embodiment is performed.
- FIG. 9 is a diagram for explaining the relationship between the limit current and response of the air-fuel ratio sensor, where the horizontal axis represents the limit current and the vertical axis represents the response.
- the limit current IL is a limit current for an air-fuel ratio (fixed value) of about 14 to 15, and the response is obtained when the air-fuel ratio is changed to the air-fuel ratio (fixed value). This is the time until the start of 3% change in the air-fuel ratio.
- the output characteristic of the limit current and the response characteristic have a 1: 1 correlation, and the limit current increases.
- the sensor has a tendency (indicating a lean output), the response tends to be faster.
- a correction value related to responsiveness is calculated according to the correction coefficient obtained in the first embodiment.
- the relationship between the correction coefficient for the limit current and the correction value for the responsiveness is obtained in advance by experiments or the like and stored in the control device 14 as a map. In actual control, the control device 14 sets a correction value for responsiveness according to the correction coefficient for the limit current according to this map.
- FIG. 10 is a flowchart for explaining a control routine executed by the control device 14 in the embodiment of the present invention.
- the routine of FIG. 10 is the same as the routine of FIG. 4 except that step S402 is included after step S112.
- a correction value related to the responsiveness of the Fr sensor 10 according to each correction coefficient are respectively calculated (S402).
- the relationship between the correction value for responsiveness and the correction coefficient for the limit current is determined in advance as a map and stored in the control device 14.
- a correction value relating to responsiveness is obtained according to this map.
- the correction value for the responsiveness of the Fr sensor 10 can be more easily calculated using the correction coefficient for the limit current. Therefore, a plurality of characteristics of both the sensors 10 and 12 can be easily matched, and the accuracy of detecting the failure of the catalyst 6 can be further increased.
- the case where the correction value for the output and responsiveness of the Fr sensor 10 is calculated based on the output of the Rr sensor 12 has been described.
- the Rr sensor 12 may be corrected using the Fr sensor 10 as a reference, and the outputs and responsiveness of both the sensors 10 and 12 may be corrected.
- the correction coefficient related to responsiveness is not limited to that calculated according to the output correction coefficient.
- the responsiveness has a correlation with the limit current IL. Therefore, the correction coefficient related to responsiveness may be calculated according to the difference between the Fr sensor 10 output and the Rr sensor 12 output.
- FIG. FIG. 11 is a schematic diagram for explaining the overall configuration of the system according to the fifth embodiment of the present invention.
- the system of the fifth embodiment has the same configuration as the system of FIG. 1 except that it does not have the Fr sensor 10 upstream of the catalyst 6 but has an in-cylinder pressure sensor 20.
- the internal combustion engine 2 includes a plurality of cylinders, and each cylinder is provided with an in-cylinder pressure sensor (first sensor) 20.
- the in-cylinder pressure sensor 20 is a sensor that generates an output corresponding to the pressure.
- Each in-cylinder pressure sensor 20 is connected to the control device 14.
- the control device 14 can detect the combustion pressure in the combustion chamber of each cylinder in response to the output signal of each cylinder pressure sensor 20.
- control device 14 calculates the heat generation amount according to the obtained combustion pressure, and calculates the fuel consumption amount according to the heat generation amount. Further, the air-fuel ratio is calculated based on the intake air amount and the fuel consumption amount. In the following embodiments, the air-fuel ratio calculated based on the output of the in-cylinder pressure sensor 20 is also referred to as “CPS air-fuel ratio”, and the air-fuel ratio calculated based on the output of the Rr sensor 12 is also referred to as “AFS air-fuel ratio”. And
- FIG. 12 is a diagram for explaining the relationship of the air-fuel ratio based on the outputs of both sensors 10 and 12 before and after correction in the fifth embodiment of the present invention.
- the horizontal axis represents the AFS air-fuel ratio
- the vertical axis represents the CPS air-fuel ratio.
- the broken line indicates the relationship between the corrected AFS air-fuel ratio and the CPS air-fuel ratio
- the plot indicates the relationship between the AFS air-fuel ratio and the CPS air-fuel ratio based on the actual measurement values.
- the correction coefficient is calculated so that the CPS air-fuel ratio (or a parameter for calculating the CPS air-fuel ratio) matches the AFS air-fuel ratio.
- the correction coefficient is a ratio between the CPS air-fuel ratio and the APS air-fuel ratio obtained by the following equation (2).
- Ratio of air-fuel ratio CPS air-fuel ratio / AFS air-fuel ratio (2)
- the ratio of air-fuel ratio is calculated by the same method as the calculation of the limit current ratio in the first embodiment. That is, while the catalyst 6 is inactive, the air-fuel ratio detection is repeated to detect a plurality of samples. After the activation of the catalyst 6, an average value of the air-fuel ratio is calculated, and this average value is set as a correction coefficient for the Fr sensor 10. However, the CPS air-fuel ratio is compared with the AFS air-fuel ratio in consideration of a delay due to the volume of the exhaust path 4 and the like between the in-cylinder pressure sensor 20 and the Rr sensor 12. That is, the values when the in-cylinder pressure sensor 20 and the Rr sensor 12 are assumed to detect the same exhaust gas are compared.
- the correction coefficient for the in-cylinder pressure sensor 20 is calculated separately for the case where the air-fuel ratio is richer than the stoichiometric air-fuel ratio and the case where it is lean. That is, the correction coefficient for the lean atmosphere where the limit current IL_Rr of the Rr sensor 12 is larger than 0 and the correction coefficient for the rich atmosphere where IL_Rr is 0 or less are divided, and the correction coefficient (average value) is calculated for each. , Shall be set.
- the calculated CPS air-fuel ratio based on the CPS air-fuel ratio output is affected by the intake air amount and the engine speed. Accordingly, in calculating the correction coefficient, the intake air amount is divided into three regions GA1, GA2, and GA3, and the engine speed is divided into nine regions NE1, NE2, and NE3. Suppose that correction coefficients of correction coefficients K1 to K9 are calculated. As described above, the correction coefficient in the fifth embodiment is controlled as a map defined by the relationship between the intake air amount and the engine speed for each of cases where the AFS air-fuel ratio is rich and lean as described above. Stored in the device.
- FIG. 13 is a flowchart for illustrating a control routine executed by control device 14 in the fifth embodiment of the present invention.
- the routine of FIG. 13 it is first determined whether or not the precondition for calculating the correction coefficient of the in-cylinder pressure sensor 20 is satisfied (S502).
- the specific conditions are that the internal combustion engine 2 is instructed to start, that the in-cylinder pressure sensor 20 and the air-fuel ratio sensor 12 are both in an active state and that the estimated temperature of the catalyst 6 is higher than a predetermined temperature. It is preset and stored in the control device 14 such as low.
- the CPS air-fuel ratio and the AFS air-fuel ratio are detected (S504).
- the CPS air-fuel ratio is obtained according to the arithmetic expression stored in the control device.
- the AFS air-fuel ratio is detected according to the limit current that is the output of the Rr sensor 12. As described above, it is assumed here that the air-fuel ratio for the same exhaust gas is obtained in consideration of the delay of the volume between the in-cylinder pressure sensor 20 and the Rr sensor 12.
- step S510 if the catalyst activity is not recognized, the process returns to step S504 again to obtain the CPS air-fuel ratio and the AFS air-fuel ratio, and in step S506, the ratio is obtained. Thereafter, in accordance with steps S508 to S510, it is determined whether or not catalytic activity is recognized. As described above, the processes in steps S504 to S510 are repeatedly executed until the catalyst activity is recognized in step S510.
- a correction coefficient is calculated (S512).
- the ratio of the air-fuel ratio obtained in step S506 is divided into a case where IL_Rr> 0 (lean) and a case where IL_Rr ⁇ 0 (rich), and further, the engine speed described above.
- the intake air amount is divided into regions. Then, an average value of the air-fuel ratio is obtained for each region. This average value is set as a correction coefficient for each region.
- the ratio of the air-fuel ratio larger than the limit value which is a guard value is set so as not to be used. Thereafter, the current process ends.
- the set correction coefficient is used as a correction coefficient for correcting the CPS air-fuel ratio until a new correction coefficient is set.
- the CPS air-fuel ratio calculated based on the in-cylinder pressure sensor 20 can be used even when the in-cylinder pressure sensor is used without installing the air-fuel ratio sensor upstream of the catalyst 6. Can be corrected. Therefore, even in a system that detects the air-fuel ratio based on the output of the in-cylinder pressure sensor 20, high accuracy of air-fuel ratio control can be secured.
- the AFS air-fuel ratio is divided into a rich case and a lean case, and further, the engine speed and the intake air amount are divided into three regions, and a correction coefficient is set for each region.
- the correction coefficient is not set for each region in this way, and only one correction coefficient may be obtained and used as a correction coefficient for the CPS air-fuel ratio.
- the intake air amount and the engine speed that affect the calculation of the CPS air-fuel ratio are each divided into three regions has been described.
- the parameters for setting such a region in the present invention are not limited to the intake air amount and the engine speed, and other parameters that affect the calculation of the CPS air-fuel ratio may be used.
- the area is not limited to three. The same applies to the following embodiments.
- the air-fuel ratio is detected a plurality of times and the average value of the air-fuel ratio is used as the correction coefficient.
- the present invention is not limited to this.
- the air-fuel ratio may be detected once and used for calculating the correction coefficient.
- the correction coefficient is not limited to the air-fuel ratio, but is calculated according to the difference between the CPS air-fuel ratio and the ADS air-fuel ratio, or other differences (difference, ratio, etc.) between the CPS air-fuel ratio and the AFS air-fuel ratio. It may be a value. The same applies to the following embodiments.
- Embodiment 6 FIG.
- the system of the sixth embodiment has the same configuration as the system shown in FIG.
- the control device 14 according to Embodiment 6 of the present invention controls the air-fuel ratio to the correction air-fuel ratio for calculating the correction coefficient when detecting the CPS air-fuel ratio and the AFS air-fuel ratio performed before the activation of the catalyst 6 for calculating the correction coefficient. Except for this point, the same control as in the fifth embodiment is performed.
- the sixth embodiment in the same way as in the second embodiment, several different correction airspaces are previously set so that the air-fuel ratio is greatly rich or lean in the range of 14.0-15.2.
- the fuel ratio is set and stored in the control device 14.
- the air-fuel ratio is controlled using one rich air-fuel ratio of the correction air-fuel ratio as the target air-fuel ratio.
- the air-fuel ratio is detected at this rich air-fuel ratio.
- the air-fuel ratio is determined for each of the other lean or rich air-fuel ratios among the correction air-fuel ratios.
- the air-fuel ratio is determined for all correction air-fuel ratios set in this way.
- the average value of the ratios of the respective air-fuel ratios is calculated for each region of the intake air amount and the engine speed described in the fifth embodiment, and for each rich and lean range, and this is calculated as a correction coefficient in calculating the CPS air-fuel ratio. To do.
- FIG. 14 is a flowchart for illustrating a control routine executed by control device 14 in the sixth embodiment of the present invention.
- the routine of FIG. 14 is the same as the routine of FIG. 13 except that the process of step S602 is provided between steps S502 and S504 and that the process of step S604 is provided after step S510.
- the target air-fuel ratio is set to an air-fuel ratio in which the air-fuel ratio is not detected among the correction air-fuel ratios, and the air-fuel ratio control is executed. (S602).
- the CPS air-fuel ratio and the AFS air-fuel ratio in the current air-fuel ratio are detected (S504), and the ratio is calculated (S506). Thereafter, detection of the catalyst temperature and determination of the catalyst activity are executed (S508 to S510), and if the catalyst activity is not recognized, is the calculation of the ratio of the air-fuel ratio for all the predetermined correction air-fuel ratios completed? It is determined whether or not (S604). If it is not recognized that the calculation of the air-fuel ratio has been completed, the process returns to S602 again, and the target air-fuel ratio is set to another air-fuel ratio for which the air-fuel ratio has not yet been detected among the correction air-fuel ratios. Control of the air-fuel ratio is controlled. In this state, the processes of steps S504 to S506 are executed.
- a correction coefficient is calculated (S512). Specifically, the correction coefficient is calculated separately for each region in Table 1, when the air-fuel ratio is rich and when it is lean. Again, a limit value is set, and when the air-fuel ratio is larger than the guard value, it is not used for calculating the correction coefficient.
- the air-fuel ratio is largely controlled in the range from rich to lean.
- a more appropriate correction coefficient can be calculated using a value when a difference in behavior between the in-cylinder pressure sensor 20 and the air-fuel ratio sensor 12 appears greatly.
- the setting range of the correction air-fuel ratio is not limited to this.
- the setting range of the correction air-fuel ratio is the same as in the second embodiment.
- the correction air-fuel ratio is not limited to the entire region on the lean side and the rich side, but a fixed region in which the CPS air-fuel ratio should be particularly corrected may be set, and the correction may be centered on that region.
- FIG. 15 is a diagram showing a region in which variation is likely to occur in the CPS air-fuel ratio in the seventh embodiment of the present invention.
- the fuel consumption is calculated based on the calorific value obtained from the combustion pressure. For this reason, when the fuel is excessive (the air / fuel ratio is rich), the sensitivity is reduced, and the detection accuracy of the CPS air / fuel ratio is liable to be lowered (see the region of the dashed line in FIG. 15). Therefore, the range of the correction air-fuel ratio is set to the rich side so that many samples on the rich side are detected.
- the correction coefficient for the region where the air-fuel ratio is rich may be calculated with priority.
- the region in which the correction coefficient is calculated in this manner is not necessarily limited to the rich side.
- the CPS air-fuel ratio and the AFS air-fuel ratio are A region where the difference between the two values exceeds the permissible range is specified, and the correction coefficient may be calculated intensively under the operating conditions corresponding to the region.
- FIG. 16 is a schematic diagram for explaining the overall system configuration according to the seventh embodiment of the present invention.
- the internal combustion engine 2 has an EGR system 30.
- the EGR system 30 is a system that recirculates a part of the exhaust gas flowing through the exhaust path 4 of the internal combustion engine 2 to the intake pipe 34 via the EGR pipe 32.
- An EGR valve 36 is installed in the EGR pipe 32.
- the EGR valve 36 is opened and closed and its opening degree is controlled by a control signal from the control device 14.
- the control of the EGR valve 36 controls the exhaust gas flow rate and the like when EGR is present (ON), absent (OFF), and when EGR is ON.
- the seventh embodiment the effect of ON / OFF of EGR on the CPS air-fuel ratio is learned, and the correction coefficient is set so that variation due to the effect of EGR is reduced.
- the control performed by the system of the seventh embodiment is the same as that of the system of the sixth embodiment, except that the correction coefficient is detected separately when the EGR is ON and when it is OFF. Shall.
- the control is performed to the predetermined correction air-fuel ratio, the CPS air-fuel ratio and the AFS air-fuel ratio are detected, and the correction coefficient is calculated.
- the corrected CPS air-fuel ratio is calculated according to the following equation (3).
- Corrected CPS air-fuel ratio K ⁇ CPS air-fuel ratio + T ⁇ EGR amount (3)
- K is a correction coefficient when EGR is OFF.
- T is a correction amount of the CPS air-fuel ratio with respect to the EGR amount.
- FIG. 17 is a control routine executed by the control device 14 in the seventh embodiment of the present invention.
- the routine of FIG. 16 it is first determined whether or not the precondition is satisfied as in the fifth embodiment (S702). If the precondition is not satisfied, the current process is terminated. On the other hand, if the establishment of the precondition is confirmed in step S702, the air-fuel ratio is then set to a correction air-fuel ratio for correction (S704).
- the correction air-fuel ratio is a predetermined air-fuel ratio set in advance within a predetermined range as in the sixth embodiment. Here, it is effective that the correction air-fuel ratio is the rich-side air-fuel ratio.
- EGR is turned off (S706).
- the CPS air-fuel ratio is detected, the AFS air-fuel ratio is detected, and the air-fuel ratio ratio is calculated (S708 to S710).
- EGR is turned on (S712).
- the CPS air-fuel ratio and the AFS air-fuel ratio are detected, and the ratio of the air-fuel ratio is calculated (S714 to S716).
- the catalyst temperature is detected (S718), and it is determined whether catalyst activity is recognized (S720). If the catalyst activity is not recognized, it is determined whether or not the calculation of the air-fuel ratio is completed for all the correction air-fuel ratios (S722).
- step S704 If the calculation of the air-fuel ratio is not completed, control is made to another correction air-fuel ratio (S704), and the processing of steps S706 to S720 is repeated. On the other hand, if catalyst activity is recognized in step S720, or if calculation of the air-fuel ratio is completed in step S722, a correction coefficient is calculated in step S724.
- correction amount T for the EGR amount is calculated from the ratio of the air-fuel ratio between when the EGR under the same condition is ON and when it is OFF (S726). Thereafter, the current process ends.
- the correction amount when EGR is ON is calculated. Therefore, even when EGR is ON and the CPS air-fuel ratio tends to vary, the CPS air-fuel ratio can be corrected more appropriately.
- the correction air-fuel ratio is set and the correction coefficient for each correction air-fuel ratio is set depending on whether EGR is ON or OFF has been described.
- the present invention is not limited to this, and the correction air-fuel ratio may be only on the rich side. Further, not only when the air-fuel ratio for correction is controlled, the processing in steps S706 to S724 may be executed with the air-fuel ratio in the operation state unchanged.
- the calculation of the correction coefficient when the EGR of the seventh embodiment is ON or OFF can be applied to, for example, the fifth embodiment.
- the correction of the EGR amount is performed by obtaining the air-fuel ratio for each region when the EGR is turned on and off for each region of the fifth embodiment and comparing the air-fuel ratio for each region.
- the amount T may be set for each region.
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Abstract
Description
図1は、この発明の実施の形態1におけるシステムの全体構成について説明するための模式図である。図1のシステムは車両等に搭載されて用いられる。図1において、内燃機関2の排気経路4には、触媒6、8が設置されている。
限界電流比=IL_Rr/IL_Fr ・・・(1)
本実施の形態2のシステムは、図1に示すシステムと同様の構成を有している。本発明の実施の形態2の制御装置14は、補正係数算出のため、触媒活性前の空燃比センサ10、12の限界電流の検出を行う場合に、空燃比を補正係数算出用の空燃比に制御する点を除き、実施の形態1と同様の制御を行う。
実施の形態3のシステムは、図1のシステムと同様の構成を有している。実施の形態1、2では空燃比センサ10、12の特性としての出力(限界電流)に対し補正係数の算出をしたのに対し、実施の形態3のシステムは、両センサ10、12の特性である応答性に対し、補正値を算出する点において、実施の形態1、2と異なる制御を行う。
実施の形態4のシステムは、図1のシステムと同様の構成を有している。実施の形態4においては、Frセンサ10とRrセンサ12との限界電流に対する補正係数を求めると共に、その限界電流に応じて、両センサ10、12の応答性を補正するための補正値を検出する点を除き、実施の形態1のシステムと同様の制御を行うものである。
図11は、この発明の実施の形態5のシステムの全体構成について説明するための模式図である。実施の形態5のシステムは、触媒6上流側のFrセンサ10を有さず、筒内圧センサ20を有する点を除き、図1のシステムと同じ構成を有している。
空燃比の比=CPS空燃比/AFS空燃比 ・・・(2)
本実施の形態6のシステムは、図11に示すシステムと同様の構成を有している。本発明の実施の形態6の制御装置14は、補正係数算出のため触媒6の活性前に行うCPS空燃比、AFS空燃比の検出に際し、空燃比を補正係数算出用の補正用空燃比に制御する点を除き、実施の形態5と同様の制御を行う。
実施の形態7のシステムは、EGRシステムを有する点を除き、実施の形態5のシステムと同様の構成を有する。図16は、この発明の実施の形態7におけるシステム全体構成を説明するための模式図である。図16に示されるように、内燃機関2は、EGRシステム30を有している。EGRシステム30は、内燃機関2の排気経路4を流れる排気ガスの一部を、EGR管32を介して吸気管34に再循環させるシステムである。EGR管32には、EGRバルブ36が設置されている。EGRバルブ36は、制御装置14からの制御信号により開閉及びその開度が制御される。EGRバルブ36の制御により、EGRの有り(ON)、無し(OFF)及びEGRがONの場合の排気ガスの流量等が制御される。
補正CPS空燃比=K×CPS空燃比+T×EGR量 ・・・・(3)
上記式においてKは、EGRがOFFの場合の補正係数である。また、Tは、EGR量に対するCPS空燃比の補正量である。
6、8 触媒
10 空燃比センサ(Frセンサ)
12 空燃比センサ(Rrセンサ)
14 制御装置
20 筒内圧センサ
30 EGRシステム
Claims (9)
- 内燃機関の排気経路の触媒の上流に設置された第1センサの特性と、前記触媒下流に設置された空燃センサである第2センサの特性とを検出する特性検出手段と、
前記第1センサの特性に基づいて第1空燃比を算出すると共に、前記第2センサの特性に基づいて第2空燃比を算出する算出手段と、
前記内燃機関の始動後、かつ前記触媒が未活性の状態のときの、前記第1特性と前記第2特性との差異、又は、前記第1空燃比と前記第2空燃比との差異を検出する差異検出手段と、
前記差異に応じて、前記第1空燃比と前記第2空燃比とが同一となるように、前記第1センサ及び/又は前記第2センサの特性を補正する補正手段と、
を備えることを特徴とするセンサの特性補正装置。 - 前記第1センサは、空燃比センサであって、
前記特性検出手段は、前記第1センサの特性及び前記第2センサの特性として、それぞれの出力を検出し、
前記差異検出手段は、前記第1センサの出力と前記第2センサの出力との差異を検出し、
前記補正手段は、前記差異に応じて、前記第1センサ及び/又は前記第2センサの出力を補正することを特徴とする請求項1に記載の比センサの特性補正装置。 - 前記補正手段は、前記差異に応じて、前記第1センサ及び/又は前記第2センサの応答性を、更に補正することを特徴とする請求項2に記載のセンサの特性補正装置。
- 前記第1センサは、空燃比センサであって、
前記特性検出手段は、前記第1センサの特性及び前記第2センサの特性として、それぞれの応答性を検出し、
前記差異検出手段は、前記第1センサの応答性と前記第2センサの応答性との差異を検出し、
前記補正手段は、前記差異に応じて、前記第1センサ及び/又は前記第2センサの応答性を補正することを特徴とする請求項1に記載のセンサの特性補正装置。 - 前記補正手段は、前記第2センサの特性を基準とし、前記第1空燃比が前記第2空燃比と同一となるように、前記第1センサの特性を補正することを特徴とする請求項2から4のいずれか1項に記載のセンサの特性補正装置。
- 前記第1センサは、筒内圧センサであって、
前記差異検出手段は、前記第1空燃比と前記第2空燃比との差異を検出し、
前記補正手段は、前記差異に応じて、前記第1空燃比を補正することを特徴とする請求項1に記載のセンサの特性補正装置。 - 前記差異検出手段は、内燃機関がEGR有りの運転状態である場合と、EGR無しの運転状態である場合とのそれぞれの運転状態において、前記第1空燃比と前記第2空燃比との差異を検出し、
前記補正手段は、前記EGR有りの運転状態における差異と、前記EGR無しの運転状態における差異とを比較して、前記EGR有りの運転状態における、EGR量に対する補正係数を、更に、算出することを特徴とする請求項6又は7に記載のセンサの特性補正装置。 - 前記内燃機関の始動後、かつ前記触媒が未活性の状態において、前記内燃機関の空燃比を、所定のリッチ空燃比に制御する空燃比制御手段を、更に備え、
前記差異検出手段は、前記リッチ空燃比に制御されている場合の前記第1空燃比と前記第2空燃比との差異を検出することを特徴とする請求項6又は7に記載のセンサの特性補正装置。 - 前記内燃機関の始動後、かつ前記触媒が未活性の状態において、前記内燃機関の空燃比を、所定のリッチ空燃比又はリーン空燃比に制御する空燃比制御手段を、更に備え、
前記差異検出手段は、前記リッチ空燃比又はリーン空燃比に制御されている場合の、前記第1センサと前記第2センサとの特性の差異、又は前記第1空燃比と前記第2空燃比との差異を検出することを特徴とする請求項1から7のいずれか1項に記載のセンサの特性補正装置。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP11865973.9A EP2716899B1 (en) | 2011-05-24 | 2011-05-24 | Sensor characteristic correction device |
CN201180071082.3A CN103547785B (zh) | 2011-05-24 | 2011-05-24 | 传感器的特性补正装置 |
PCT/JP2011/061882 WO2012160651A1 (ja) | 2011-05-24 | 2011-05-24 | センサの特性補正装置 |
JP2013516108A JP5556962B2 (ja) | 2011-05-24 | 2011-05-24 | センサの特性補正装置 |
US14/006,405 US9163574B2 (en) | 2011-05-24 | 2011-05-24 | Sensor characteristic correction device |
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PCT/JP2011/061882 WO2012160651A1 (ja) | 2011-05-24 | 2011-05-24 | センサの特性補正装置 |
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US (1) | US9163574B2 (ja) |
EP (1) | EP2716899B1 (ja) |
JP (1) | JP5556962B2 (ja) |
CN (1) | CN103547785B (ja) |
WO (1) | WO2012160651A1 (ja) |
Cited By (2)
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JP2015102023A (ja) * | 2013-11-25 | 2015-06-04 | トヨタ自動車株式会社 | 空燃比センサの異常診断装置 |
US9334776B2 (en) | 2012-09-20 | 2016-05-10 | Toyota Jidosha Kabushiki Kaisha | Control device for internal combustion engine |
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JP5648706B2 (ja) * | 2013-04-19 | 2015-01-07 | トヨタ自動車株式会社 | 内燃機関の空燃比制御装置 |
JP6344016B2 (ja) * | 2014-03-31 | 2018-06-20 | 株式会社デンソー | 温度測定装置 |
US20160055536A1 (en) * | 2014-08-21 | 2016-02-25 | Verizon Patent And Licensing Inc. | Providing offers for purchase based on real-time user data |
JP6507823B2 (ja) * | 2015-04-27 | 2019-05-08 | 三菱自動車工業株式会社 | エンジンの制御装置 |
DE102021214192A1 (de) | 2021-12-13 | 2023-06-15 | Robert Bosch Gesellschaft mit beschränkter Haftung | Verfahren zum Ermitteln einer Funktionsfähigkeit eines Abgassensors in einem Abgassystem einer Brennkraftmaschine |
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- 2011-05-24 CN CN201180071082.3A patent/CN103547785B/zh not_active Expired - Fee Related
- 2011-05-24 EP EP11865973.9A patent/EP2716899B1/en not_active Not-in-force
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JP2015102023A (ja) * | 2013-11-25 | 2015-06-04 | トヨタ自動車株式会社 | 空燃比センサの異常診断装置 |
Also Published As
Publication number | Publication date |
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JPWO2012160651A1 (ja) | 2014-07-31 |
US20140005882A1 (en) | 2014-01-02 |
CN103547785B (zh) | 2016-04-13 |
EP2716899A4 (en) | 2015-12-02 |
CN103547785A (zh) | 2014-01-29 |
JP5556962B2 (ja) | 2014-07-23 |
US9163574B2 (en) | 2015-10-20 |
EP2716899A1 (en) | 2014-04-09 |
EP2716899B1 (en) | 2018-04-04 |
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