JPH1018894A - Abnormality judging method for atmospheric pressure sensor of engine and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and correctly judge an abnormal condition such that the sensitivity of an atmospheric pressure sensor is reduced and the like by judging whether the deviation between the maximum value and the minimum value of atmospheric pressure is a referential value or less or not, the abnormality of the atmospheric pressure sensor is judged in the case of the referential value or less. SOLUTION: A calculating means 14 is arranged to calculate the filling efficiency of intake on the basis of the detecting signal of an intake air rate outputted from an air flow meter 5. A memory means 17 is arranged to memorize a filling efficiency and the maximum value and the minimum value of atmospheric pressure when an engine is in a specified operating condition. A means 19 is arranged to judge the abnormality of an atmospheric pressure sensor for detecting intake pressure led into an intake passage, namely, for detecting atmospheric pressure. It is judged whether the deviation between the maximum value and the minimum value of atmospheric pressure is a referential value or less or not, the abnormality of the atmospheric pressure sensor is judged when the deviation is the referential value or less. It is possible to simply and correctly judge the normality of the atmospheric pressure sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for determining an abnormality of an atmospheric pressure sensor of an engine for determining an abnormality of an atmospheric pressure sensor used for controlling the engine.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 58-101244
As shown in the publication, in an electronic control engine configured to detect an intake pressure supplied to a combustion chamber of an automobile engine by an intake pressure sensor provided downstream of the throttle valve, the throttle valve When the intake pressure is at the idling opening and the intake pressure detected by the intake pressure sensor is larger than a predetermined value, or when the throttle valve is at or below the predetermined opening larger than the idling opening and the intake air detected by the intake pressure sensor is When the detected value of the pressure is larger than a value calculated as a predetermined function of the engine speed and the throttle valve opening, it is determined that an abnormality such as a disconnection of the signal line of the intake pressure sensor has occurred. Have been done.

That is, in the above-described abnormality determination, for example, during an idling operation of the engine, the detected value of the intake pressure detected by the intake pressure sensor provided downstream of the throttle valve becomes a large value that cannot normally occur. In this case, the detection is performed by determining that the detected value has become the above value due to the failure of the intake pressure sensor.

[0004]

According to the abnormality judging method having the above-described structure, in order to detect the intake pressure downstream of the throttle valve installed in the intake passage, that is, the negative pressure acting on the downstream portion of the intake passage. Even if it is possible to determine the abnormality of the provided intake pressure sensor, there is a problem that it is not possible to determine the abnormality of the intake pressure upstream of the throttle valve, that is, the atmospheric pressure sensor that detects the atmospheric pressure.

[0005] In addition, the disconnection of the signal line of the pressure sensor, or the disconnection of the piping communicating with the installation portion of the pressure sensor or the like, causes the detection value of the pressure sensor to be a large value that cannot normally occur. In the case where the pressure sensor becomes abnormal, if an abnormality such as a predetermined error occurs in the detection value due to a decrease in the sensitivity of the pressure sensor or the like, even if the abnormality of the pressure sensor can be determined, However, there is a problem that this cannot be determined.

[0006] In view of such circumstances, the present invention can determine the abnormality of the atmospheric pressure sensor provided upstream of the throttle valve, and can easily detect the abnormality such as a decrease in the sensitivity of the atmospheric pressure sensor. Another object of the present invention is to provide a method and a device for determining an abnormality of an atmospheric pressure sensor of an engine which can be accurately determined.

[0007]

The invention according to claim 1 is
In an abnormality determination method for determining an abnormality of an atmospheric pressure sensor used for controlling an engine, an intake air amount detected by an air flow meter provided in an intake passage when it is confirmed that the engine is in a specific operation state. After calculating the value related to the charging efficiency of the intake air according to the above, and sequentially reading the calculated value, sequentially reading the detected value of the atmospheric pressure detected by the atmospheric pressure sensor, the calculated value of the value related to the charging efficiency and the atmospheric pressure The maximum value and the minimum value are obtained based on the detected value of the pressure, and it is determined whether the deviation between the maximum value and the minimum value of the value related to the intake efficiency is larger than a preset reference value. At that point, it is determined whether or not the deviation between the maximum value and the minimum value of the atmospheric pressure is equal to or less than a preset reference value. It is to determine the atmospheric pressure sensor is abnormal if it is confirmed.

According to the above configuration, the maximum value and the minimum value of these values are selected based on the calculated value of the value related to the charging efficiency and the detected value of the atmospheric pressure which are read when the engine is in the specific operating state. After that, despite the occurrence of a predetermined deviation corresponding to a change in the atmospheric pressure or the like between the maximum value and the minimum value of the value related to the charging efficiency, the maximum value of the atmospheric pressure detected by the atmospheric pressure sensor is obtained. When it is confirmed that there is no difference between the value and the minimum value, the atmospheric pressure sensor is determined to be abnormal.

According to a second aspect of the present invention, there is provided a method for determining an abnormality of an atmospheric pressure sensor of an engine according to the first aspect.
When the change rate of the amount of intake air detected by the air flow meter is confirmed to be equal to or less than a preset reference value, the calculated value of the charging efficiency and the detected value of the atmospheric pressure are read. It was done.

According to the above configuration, when it is confirmed that the change rate of the intake air amount detected by the air flow meter is small and the pulsation of the intake air is small, the charging of the intake air calculated according to the intake air amount is performed. The efficiency and the atmospheric pressure detected by the atmospheric pressure sensor are read, and the abnormality of the atmospheric pressure sensor is determined based on these values.

According to a third aspect of the present invention, in the method for determining an abnormality of an atmospheric pressure sensor of an engine according to the first or second aspect, the rate of change of the charging efficiency calculated according to the intake air amount is a predetermined reference value. When it is confirmed that the value is equal to or less than the value, the calculated value of the value related to the charging efficiency and the detected value of the atmospheric pressure are read.

According to the above configuration, when the rate of change of the charging efficiency calculated according to the intake air amount is small and it is confirmed that the engine is in a steady operation state, the calculation is performed according to the intake air amount. The intake air filling efficiency and the atmospheric pressure detected by the atmospheric pressure sensor are read, and the abnormality of the atmospheric pressure sensor is determined based on these values.

According to a fourth aspect of the present invention, there is provided an abnormality determining device for determining an abnormality of an atmospheric pressure sensor used for controlling an engine, wherein an operating state determining means for determining whether or not the engine is in a specific operating state; Calculating means for calculating a value related to intake air charging efficiency in accordance with an intake air amount detected by an air flow meter provided in an intake passage when the operating state determining means determines that the engine is in a specific operating state; Based on the value related to the charging efficiency calculated by the calculating means and the atmospheric pressure detected by the atmospheric pressure sensor when the engine is confirmed to be in the specific operating state, Storage means for selecting and storing the maximum value and the minimum value, and the maximum value of the value related to the charging efficiency stored in the storage means At the time when it is determined whether the deviation from the small value is larger than a preset reference value and it is confirmed that the deviation is larger, the deviation between the maximum value and the minimum value of the atmospheric pressure stored in the storage means is determined. Abnormality determining means for determining whether or not the pressure is equal to or less than a predetermined reference value, and determining that the atmospheric pressure sensor is abnormal when it is determined that the value is equal to or less than the reference value.

According to the above configuration, the maximum value of these values is calculated based on the calculated value of the value related to the charging efficiency and the detected value of the atmospheric pressure at the time when the operating state determining means confirms that the engine is in the specific operating state. And a minimum value are selected and stored in the storage means, respectively, and a predetermined deviation corresponding to a change in atmospheric pressure or the like is provided between the maximum value and the minimum value of the value related to the charging efficiency stored in the storage means. It is determined that the atmospheric pressure sensor is abnormal when it is confirmed that there is no difference between the maximum value and the minimum value of the atmospheric pressure detected by the atmospheric pressure sensor despite the occurrence of Will be.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration of an engine provided with an abnormality determination device for an atmospheric pressure sensor of an engine according to an embodiment of the present invention. This engine has an engine body 1, an intake passage 2, and an exhaust passage 3.
In the intake passage 2, an air cleaner 4, an air flow meter 5, a throttle valve 6, a surge tank 7, and a fuel injection valve 8 are provided in this order from the upstream side. The air flow meter 5 includes a mass flow meter such as a so-called hot wire or a heat register, and is configured to detect the weight of the intake air introduced into the intake passage 2.

The intake passage 2 is provided with a bypass passage 9 for bypassing a portion where the throttle valve 6 is installed.
Is installed. When the engine in which the throttle valve 6 is closed is idling, the idle control valve 10 is opened and closed according to a control signal output from an engine control unit (ECU) 11, so that the bypass passage 9 is opened. , The amount of intake air introduced into the combustion chamber 12 of the engine body 1 is adjusted, and idling control for matching the engine speed to a predetermined idle speed is executed.

As shown in FIG. 2, the engine control unit 11 includes a detection signal of an intake air amount output from the air flow meter 5 and a detection signal output from a rotation sensor 13 for detecting an engine speed. Calculation means 14 for calculating the charging efficiency of the intake air supplied to the combustion chamber 12 of the engine body 1 based on the calculation is provided.

The engine control unit 11 includes an operating state determining means 15 for determining whether or not the engine is in the following specific operating state, and a throttle sensor 16 for detecting the opening of the throttle valve 6. A storage means 17 for storing the maximum value and the minimum value of the charging efficiency and the atmospheric pressure obtained at the time when it is confirmed that the engine is in the specific operation state according to the signal and the like, and is introduced into the intake passage 2. Abnormality judging means 1 for judging an abnormality of an atmospheric pressure sensor 18 for detecting an intake air pressure, that is, an atmospheric pressure.
9 are provided.

The operating state determining means 15 determines that the rate of change of the intake air amount detected by the air flow meter 5 and the rate of change of the charging efficiency calculated by the calculating means 14 are each equal to or less than a preset reference value. If
When it is determined that the engine is in a steady operation state, and the opening degree of the throttle valve 6 detected by the throttle sensor 16 and the charging efficiency calculated by the calculating means 14 are respectively within predetermined ranges, It is configured to determine that the engine is in a specific operating state.

The abnormality determining means 19 determines whether the deviation between the maximum value and the minimum value of the charging efficiency stored in the storage means 17 is larger than a preset reference value, and confirms that the difference is large. At this point, a deviation between the maximum value and the minimum value of the atmospheric pressure stored in the storage means 17 is obtained, and when it is confirmed that the deviation is equal to or less than a preset reference value, the atmospheric pressure sensor 18 is activated. It is configured to determine that an abnormality has occurred, and to output a command signal to the display means 20 to display that an abnormality has occurred in the atmospheric pressure sensor 18.

The control operation performed by the abnormality determination device having the above-described configuration will be described with reference to the flowchart shown in FIG. When the above control operation starts, first, in step S
In step 1, it is determined whether or not the change rate Δq of the intake air amount is equal to or less than a preset reference value ΔQ. In step S2, the change rate Δce of the charging efficiency is equal to or less than the preset reference value ΔC. By determining whether or not the engine is operating, it is determined whether or not the engine is in a steady operation state.

YES at steps S1 and S2
When it is determined that the engine is in a steady operation state, in step S3, the opening degree tvo of the throttle valve is changed from the preset first reference value T1 to the second reference value T1.
In step S4, it is determined whether or not the engine speed ne is within a range from a first reference value N1 to a second reference value N2. Is determined, it is determined whether or not the engine is in a specific operating state.

YES at steps S3 and S4
When it is determined that the engine is in the specific operation state, the charging efficiency ce of the intake air calculated by the calculating means 14 at this time and the atmospheric pressure detected by the atmospheric pressure sensor 18 are determined in step S5. at
p is read into the storage means 17, and at step S6, the maximum value cemax and the minimum value cemin of the charging efficiency ce are selected and stored, respectively, and the maximum value atpmax and the minimum value a of the atmospheric pressure atp are selected.
tpmin is selected and stored.

That is, the conventional filling efficiency cemax stored in the storage means 17 is compared with the filling efficiency ce read in step S5, and the larger one of the two is compared with the new maximum filling efficiency. The value is selected as the value cemax and stored in the storage means 17, and the minimum value cemin of the conventional filling efficiency stored in the storage means 17 is compared with the filling efficiency ce read in step S5.
The smaller of the two is the new minimum filling efficiency cem
in is stored in the storage unit 17.

Further, the conventional maximum value atpmax of the atmospheric pressure stored in the storage means 17 is compared with the atmospheric pressure atp read in step S5, and the larger one of them is set as the new maximum of the atmospheric pressure. The value is selected as the value atpmax and is stored in the storage unit 17.
7 is the conventional minimum value of the atmospheric pressure atpmin
Is compared with the filling efficiency atp read in step S5, and the smaller of the two is selected as the new maximum value of the atmospheric pressure atpmin and stored in the storage means 17.

Next, in step S7, it is determined whether or not the difference between the maximum value cemax of the charging efficiency and the minimum value cemin is equal to or greater than a preset reference value D.
If determined to be YES, in step S8,
Atmospheric pressure maximum value atpmax and minimum value atpm
It is determined whether or not the deviation from “in” is equal to or smaller than a preset reference value A. If “YES” is determined, step S
9, a signal indicating that the atmospheric pressure sensor 18 is abnormal is output to the display means 20 and
At 10, the control operation is ended after storing the abnormal data.

If NO is determined in step S8 and it is confirmed that the deviation is larger than the reference value A, it is considered that the atmospheric pressure is correctly detected by the atmospheric pressure sensor 18. Return. Steps S1, S2, S3, S4, S
If NO is determined in any of the cases 7, it is considered that the atmospheric pressure sensor 18 is not in a state to determine whether or not it is abnormal, and the process returns.

As described above, when it is confirmed that the engine is in the specific operation state, the charging efficiency of the intake air is calculated in accordance with the intake air amount detected by the air flow meter 5 and the value is stored in the storage means 17. At the same time, after the atmospheric pressure detected by the atmospheric pressure sensor 18 is stored in the storage means 17, the difference between the maximum value and the minimum value of the charging efficiency stored in the storage means 17 is set to a predetermined reference value. It is determined whether the difference between the maximum value and the minimum value of the atmospheric pressure stored in the storage means 17 is equal to or less than a preset reference value when it is determined that the pressure is larger than Is determined, and when it is confirmed that the atmospheric pressure sensor 18 is equal to or less than the reference value, the atmospheric pressure sensor 18 is determined to be abnormal. It can be determined.

That is, the fact that the difference between the maximum value and the minimum value of the charging efficiency stored in the storage means 17 is equal to or greater than a predetermined value indicates that the engine is in substantially the same operating state. It is considered that the above-mentioned deviation has occurred in the charging efficiency of the intake air due to a change in the altitude and the like of the traveling path and a change in the atmospheric pressure. Therefore, when it is confirmed that a predetermined deviation has not occurred in the detection value of the atmospheric pressure sensor 18 despite the occurrence of the deviation between the maximum value and the minimum value of the charging efficiency, For example, if a certain abnormality occurs in the atmospheric pressure sensor 18, for example, a predetermined deviation does not occur in the detection value of the atmospheric pressure sensor 18 between when the engine is operating at a high altitude and when the engine is operating at a low altitude where the atmospheric pressure is high. You can judge.

Further, based on the deviation between the maximum value and the minimum value of the charging efficiency stored in the storage means 17 as described above and the deviation between the maximum value and the minimum value of the atmospheric pressure, the atmospheric pressure sensor 1 is used.
8 is configured to determine whether it is abnormal or not.
Abnormalities that do not cause a difference in the detection value due to a decrease in the sensitivity of the atmospheric pressure sensor 18 or the like, not only when a detection that cannot normally occur such as when the signal line of the atmospheric pressure sensor 18 is broken. Can be accurately determined.

In the above embodiment, when it is confirmed that the change rate of the intake air amount detected by the air flow meter 5 is equal to or less than a preset reference value, the intake air calculated by the calculating means 14 is calculated. Since the charging efficiency and the atmospheric pressure detected by the atmospheric pressure sensor 18 are stored in the storage means 17 and the abnormality of the atmospheric pressure sensor 18 is determined based on these values, the above-described suction due to intake pulsation is performed. It is possible to prevent erroneous determination due to abnormality determination of the atmospheric pressure sensor 18 in a state where the air amount is largely changed.

Further, in the above embodiment, when it is confirmed that the change rate of the charging efficiency obtained according to the intake air amount is equal to or less than a preset reference value, the calculating means 14
The storage efficiency of the intake pressure calculated by the above and the atmospheric pressure detected by the atmospheric pressure sensor 18 are stored in the storage means 17, and the abnormality of the atmospheric pressure sensor 18 is determined based on these values. In the transient state in which the rate of change in efficiency is large and the operating state of the engine changes significantly, it is possible to prevent erroneous determination due to the abnormality determination of the atmospheric pressure sensor 18 being performed.

The reference values T1 and T2 of the throttle opening and the reference values N1 and N2 of the engine speed for determining whether or not the engine is in a specific operation state are determined by an atmospheric pressure sensor corresponding to the fluctuation of the atmospheric pressure. 18 can be arbitrarily set within a range in which the abnormality of the atmospheric pressure sensor 18 can be accurately detected. It is desirable to set the reference values T1 and T2 of the opening to values close to the maximum opening and to set the reference values N1 and N2 of the engine speed to a low rotation region.

That is, the throttle opening reference value T
When T1 and T2 are set to values close to the maximum opening and the reference values N1 and N2 of the engine speed are set in the low rotation region, the amount of intake air flowing through the intake passage 2 becomes nearly saturated. Therefore, even if the throttle opening and the engine speed slightly change, the charging efficiency does not largely change, and the abnormality of the atmospheric pressure sensor 18 can be accurately determined.

In the above embodiment, the atmospheric pressure sensor 1 is used on the basis of the charging efficiency calculated by the calculating means 14.
Although an example has been described in which it is configured to determine whether or not the fuel injection valve 8 is operating normally, a fuel injection control (not shown) for controlling the amount of intake air per cycle or the fuel injection valve 8 in place of the above charging efficiency is performed. The atmospheric pressure sensor 18 may be configured to determine whether or not the atmospheric pressure sensor 18 is operating normally, based on a value related to the charging efficiency including the basic fuel injection amount or the like obtained by the unit.

[0036]

As described above, according to the present invention, when the engine is confirmed to be in the specific operation state, the intake air is charged according to the intake air amount detected by the air flow meter provided in the intake passage. After calculating the efficiency and storing the value in the storage means, and storing the atmospheric pressure detected by the atmospheric pressure sensor in the storage means, the maximum value and the minimum value of the filling efficiency stored in the storage means The deviation between the maximum value and the minimum value of the atmospheric pressure stored in the storage means is determined in advance when it is determined whether the deviation of the atmospheric pressure is greater than a predetermined reference value. The air pressure sensor is configured to determine whether the atmospheric pressure sensor is abnormal if it is less than the reference value. Not only can abnormalities of the pressure sensor be determined, but also detections that cannot occur normally, such as when the signal line of the atmospheric pressure sensor is broken, are also caused by reduced sensitivity of the atmospheric pressure sensor. Thus, there is an advantage that an abnormality that does not cause a difference in the detected value can be accurately determined.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of an abnormality determination device for an atmospheric pressure sensor of an engine according to the present invention.

FIG. 2 is an explanatory diagram showing a specific configuration of the abnormality determination device.

FIG. 3 is a flowchart showing a control operation of abnormality determination by the abnormality determination device.

[Explanation of symbols]

 2 Intake passage 5 Air flow meter 14 Calculating means 15 Operating state determining means 17 Storage means 18 Atmospheric pressure sensor 19 Abnormality determining means

Claims (4)

[Claims] In an abnormality determination method for determining an abnormality of an atmospheric pressure sensor used for controlling an engine, an abnormality is detected by an air flow meter provided in an intake passage when it is confirmed that the engine is in a specific operation state. Calculate a value related to the charging efficiency of the intake air according to the intake air amount thus obtained,
After sequentially reading the calculated values and sequentially reading the detected values of the atmospheric pressure detected by the atmospheric pressure sensor, based on the calculated values of the values related to the charging efficiency and the detected values of the atmospheric pressure, the maximum value and the minimum value of these values are determined. Value and
At the time when it is determined that the deviation between the maximum value and the minimum value of the values related to the intake efficiency is larger than a preset reference value and it is confirmed that the deviation is larger, the maximum value and the minimum value of the atmospheric pressure are determined. Determining whether the deviation is equal to or less than a preset reference value, and determining that the atmospheric pressure sensor is abnormal when it is confirmed that the deviation is equal to or less than the reference value. How to determine sensor abnormality. 2. When a change rate of the intake air amount detected by the air flow meter is confirmed to be equal to or less than a predetermined reference value, reading of a calculated value of the charging efficiency and a detected value of the atmospheric pressure. The method for determining an abnormality of an atmospheric pressure sensor of an engine according to claim 1, characterized in that: 3. When the change rate of the value related to the charging efficiency obtained according to the intake air amount is confirmed to be equal to or less than a predetermined reference value, the calculated value of the value related to the charging efficiency and the atmospheric pressure 3. The method according to claim 1, wherein the detection value is read. 4. An abnormality judging device for judging an abnormality of an atmospheric pressure sensor used for controlling an engine, comprising: an operating state determining means for determining whether or not the engine is in a specific operating state; When it is confirmed that the engine is in the specific operation state, a calculating means for calculating a value relating to the charging efficiency of the intake according to the intake air amount detected by the air flow meter provided in the intake passage, and the calculating means Based on the calculated value related to the charging efficiency and the atmospheric pressure detected by the atmospheric pressure sensor at the time when the engine is confirmed to be in the specific operation state, based on the value related to the charging efficiency and the maximum value and the minimum value of the atmospheric pressure, And a deviation between the maximum value and the minimum value of the values related to the charging efficiency stored in the storage means. At the time when it is determined whether the value is larger than the predetermined reference value and it is confirmed that the value is larger, the deviation between the maximum value and the minimum value of the atmospheric pressure stored in the storage means is equal to or less than a predetermined reference value. Abnormality determination means for determining whether the atmospheric pressure sensor is abnormal when it is determined that the atmospheric pressure sensor is below the reference value. Discriminator.