JP2002054966A - Operational device built-in sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an operational device built-in sensor capable of correcting deterioration with time and improving accuracy of sensor signal for a sensor having a numerical operation means and performing adjustment by digital data. SOLUTION: Action time of a sensor is measured by an action time measuring means and correction is carried out corresponding to the cumulative elapsing time. The correction is performed in a correction means 310 of the numerical operation means 300. Thus, since the sensor having a numerical operation means and performing adjustment by digital data is adapted to measure the elapsing time for usage of the sensor and perform correction operation for correcting deterioration of the sensor corresponding to the elapsing time, the operational device built-in sensor can be realized, capable of correcting deterioration with time and improving accuracy of sensor signal for the sensor having the numerical operation means and performing adjustment by digital data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a numerical operation means,
The present invention relates to a sensor for an automobile, having means for correcting a measurement error of the sensor, and in particular, a heating resistor type air flow measurement device for measuring an air flow rate based on a heat release amount from the heating resistor to the air using the heating resistor. The present invention relates to an appropriate sensor with a built-in arithmetic device used in a device.

[0002]

2. Description of the Related Art Among conventional sensors for detecting analog signals for automobiles, particularly in a heating resistor type air flow measuring device, a driving circuit using an operational amplifier or the like is used so that the temperature of the heating wire becomes a predetermined temperature. And the like, and the current flowing through the heating wire or the like is used to measure the air flow rate.

Here, the operational amplifier used for the driving circuit is:
Each resistor has an offset, and the resistors used in the drive circuit also have variations in resistance value. Therefore, in the conventional heating resistor type air flow measuring device, there is a measurement error in each heating resistor type air flow measuring device due to the offset and the variation of the resistance value.

Therefore, at the time of shipment of the heating resistor type air flow measuring device, the characteristics are checked for each unit and the output is adjusted so as to be within the specification range.

As an adjustment method at the time of shipment, conventionally,
Resistance trimming had been performed. By this resistance trimming, the zero point and the span of the output of the heating resistor type air flow measuring device are adjusted so as to be within the specification range.

[0006] However, the resistance trimming is not easy to adjust and includes an adjustment error.

Thus, for example, US Pat.
As described in the specification of Japanese Patent No. 052, electronic trimming for performing multi-point correction using digital data by using numerical calculation means is known.

Although the field of application is different, Japanese Patent Application Laid-Open No.
Japanese Patent Application Laid-Open No. 94619/1994 describes the correction means.

[0009]

However, although electronic trimming using digital data is also an effective means for securing initial accuracy, it is not effective for correcting a deviation of a sensor output signal due to aging. Was.

If the sensor has been used for a long time, the element may be deteriorated due to heat history, or the performance may be deteriorated due to the contamination of the element due to the use of the sensor. At present, the exchange of specifications with customers that do not only specify the initial accuracy but also the specifications after aging degradation.

For this reason, there has been a demand for a sensor with a built-in arithmetic unit that automatically corrects aging deterioration. SUMMARY OF THE INVENTION An object of the present invention is to provide a sensor with a built-in arithmetic device, which has a numerical operation means and performs adjustment by digital data, can correct deterioration over time, and can improve the accuracy of a sensor signal. That is.

[0012]

According to the present invention, in order to compensate for the deterioration with time of the sensor output, the actual use time of the sensor is measured, and the correction constant is determined by correlation with the measured time. Then, the sensor output is corrected.

[0013] To achieve the above object, the present invention is configured as follows. (1) In a sensor with a built-in arithmetic unit having a numerical calculation unit for correcting a measurement error, a time measuring unit that measures the accumulated time during which the sensor with a built-in arithmetic unit functions or a time corresponding to the accumulated time, and the time measuring unit And correcting means for correcting the output signal of the sensor when the measured time reaches a predetermined time for correcting the output signal of the sensor.

(2) Preferably, in the above (1),
The correction of the output signal of the sensor by the correcting means is performed based on a function corresponding to the accumulated time measured by the time measuring means or a value corresponding to the accumulated time.

(3) Preferably, in the above (1), the correction of the output signal of the sensor by the correction means is performed in accordance with a cumulative time measured by the time measuring means or a value corresponding to the cumulative time. The correction method is switched to two or more steps.

(4) Preferably, in the above (1), the time measuring means outputs an output signal of the sensor.
The time when the voltage exceeds a certain level is measured.

(5) Preferably, in the above (1), the time measuring means measures the number of times the power of the sensor is turned on.

(6) Preferably, in the above (5), the time measuring means judges that the power supply of the sensor has been performed when a predetermined time has elapsed after the power supply to the sensor, Count the number of times.

(7) In a heating resistor type air flow measuring device for measuring an air flow rate, which includes an arithmetic unit built-in sensor having numerical calculation means for correcting a measurement error, the accumulated time or accumulated time during which the measuring device functions And a correction unit that corrects the output signal of the sensor when the time measured by the time measurement unit reaches a predetermined time to correct the output signal of the sensor. .

(8) Preferably, in the above (7),
The correction of the output signal of the sensor by the correcting means is performed based on a function corresponding to the accumulated time measured by the time measuring means or a value corresponding to the accumulated time.

(9) Preferably, in the above (8), in the correction of the output signal of the sensor by the correction means, an upper limit value is set to the correction value.

(10) Preferably, in the above (7), the correction of the output signal of the sensor by the correction means is performed by accumulating the accumulated time measured by the time measuring means or a value corresponding to the accumulated time with the measured air. This is performed based on the function of the flow rate value.

(11) Preferably, the above (10)
In the above, the correction of the output signal of the sensor by the correction means is performed by switching the correction method to two or more stages according to the accumulated time measured by the time measuring means or a value corresponding to the accumulated time.

(12) Preferably, (10)
In the above, the correction of the output signal of the sensor by the correction means is performed by a correction value determined by a function of the measured air flow value.

(13) Preferably, the above (12)
In the above, the correction value is a correction value determined by switching the function of the air flow value in two or more stages.

With the above arrangement, the output signal of the sensor, whose performance deteriorates with time, is calculated by the accumulated time measuring means.
By performing the correction processing by the numerical operation means, it is possible to improve the accuracy of the output signal of the sensor.

Further, by adding a condition of the value of the output signal of the sensor to the time measuring means, or by using a counter as a means other than the timer for the measuring means, it can be widely applied from a low-cost system to a highly accurate system. A possible system can be achieved.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, a sensor for detecting an analog signal is affected by variations in the accuracy of parts depending on a circuit configuration for detecting the signal. I needed to.

As one of the sensors for detecting analog signals for automobiles, there is a heating resistor type air flow measuring device. Hereinafter, the present invention will be described as an embodiment in which the sensor with a built-in arithmetic device according to the present invention is applied to a heating resistor type air flow measuring device as one embodiment.

First, the configuration of a heating resistor type air flow measuring device according to an embodiment of the present invention will be described with reference to FIGS. 1, 8 and 9.

First, the configuration of the air flow sensor circuit 100 of the heating resistor type air flow measuring device according to one embodiment of the present invention will be described with reference to FIG.

In FIG. 9, the air flow sensor circuit 100
Is composed of a heating resistor RH arranged in the intake pipe TB for measuring the intake air flow rate, a temperature sensitive resistor RC for compensating the intake air temperature, and a drive circuit 110. The drive circuit 110 is roughly composed of a bridge circuit and a feedback circuit.

Heating resistor RH, temperature-sensitive resistor RC and resistor R
1 and R2 form a bridge circuit. The voltage across the resistor R1 and the voltage across the resistor R2 are input to the operational amplifier OP1. Thereby, the operational amplifier OP1
Constitutes a feedback circuit for supplying a heating current Ih to the heating resistor RH so as to maintain a constant temperature difference between the heating resistor RH and the temperature-sensitive resistor RC while applying feedback.

Here, when the flow velocity of the air flowing through the intake pipe TB is high, the amount of heat taken from the heating resistor RH increases, and the heating current Ih flows more. In addition, the intake pipe TB
When the flow velocity of the air flowing through the inside is low, the heating resistor RH
Since the amount of heat deprived from the heat is small, the heating current Ih is also small. That is, the heating current Ih is proportional to the flow rate of the air flowing through the intake pipe TB.

Then, the heating current Ih is detected as a voltage across the resistor R1, and an air flow sensor voltage (AFS voltage) a
Output as VtAfs.

In the prior art, this signal aVtA
Although fs is output as it is to the ECU which is the engine control device, in one embodiment of the present invention, this signal is once received by the A / D conversion means 200 shown in FIG.
Correcting means 310 of numerical operation means 300
, And outputs it as an air flow rate correction signal VtQa.

The point that this correction means 310 is provided is different from the conventional air flow measuring device AFS, and is called I-AFS (intelligent AFS) to distinguish it from the conventional type.

Next, the overall configuration and main operation of the heating resistor type air flow measuring device according to one embodiment of the present invention will be described with reference to FIGS.

FIG. 8 is a longitudinal sectional view of a main part showing a state in which a heating resistor type air flow measuring device according to one embodiment of the present invention is attached to an intake pipe.

In FIG. 8, a hole is formed in the wall surface of the main air constituting member constituting the intake pipe TB, and the heating resistor type air flow measuring device I-AFS is formed on the wall surface from outside the intake pipe TB. And is fixed to the wall surface of the intake pipe TB with screws or the like so as to maintain mechanical strength.

This heating resistor type air flow measuring device IA
As shown in the system configuration diagram of FIG. 1, the components of the FS include an A / D conversion unit 200, a numerical operation unit 300,
There are a housing member HOS containing a circuit board CB that constitutes the air flow sensor circuit 100 including the drive circuit 110 shown in FIG. 9, and a sub air passage member BP formed of a non-conductive member.

A heating resistor RH for detecting the air flow rate and a temperature-sensitive resistor RC for compensating the intake air temperature are arranged in the sub air passage component BP. The heating resistor RH and the temperature-sensitive resistor RC are electrically connected to the circuit board CB via a support HCW made of a conductive member.

Further, the housing HOS, the circuit board CB,
The sub air passage BP, the heating resistor RH, the temperature-sensitive resistor RC and the like are used as a heating resistor type air flow measuring device I-AFS.
It is configured as an integrally formed module.

The air flow rate sensor circuit 100 measures the flow rate of air taken into the intake pipe, and outputs an air flow rate sensor voltage (AFS voltage: aVtAfs). As shown in FIG. 1, the AFS voltage output from the air flow sensor circuit 100 is input to a numerical calculation unit 300 and is converted into a digital signal by an A / D conversion unit 200. Although FIG. 1 shows three signal lines (aVtAfs, aVtBrg, aVtCld) input to the A / D conversion means 200, this number is not limited to this, and other signals may be input. Or two signals may be input.

As shown in FIG. 1, the numerical operation means 300 may include the A / D means 200, or may be configured independently. A signal from the air flow sensor circuit 100 is input to the A / D conversion means 200, and the result corrected by the correction means 310 based on the data is used as an air flow correction signal (AFS voltage correction value: VtQa) by the engine control device. Output to a certain ECU.

At this time, the ECU side considers that the signal is almost always received as an analog signal, as in the related art.
On the AFS side, after performing the correction processing, the corrected signal (QaRef), which has been handled by digital data, is converted into an analog signal (V
The data is output to the ECU via the D / A conversion means 500 for conversion to tQa).

Here, the means for measuring the operation time of the sensor will be described. The numerical operation means 300 shown in FIG. The operation time measuring means 390 measures the operation time or the like by a timer or a counter while the power is turned on and the sensor is operating.

The specific logic for measuring the operation time of the sensor will be described with reference to FIG. In FIG. 3, when the power is turned on and it is recognized that the power is turned on from the battery VB via the ignition key IGN (step 20), the time is counted by the operating time measuring means 390 (step 21), and the result is obtained. Store in data storage means 400
(Step 22).

The effect of the deterioration over time changes depending on the type of element which is the detection part of the sensor. As an example, a case of a winding resistance type element widely used as an air flow sensor will be described. In this case, it is known that when the element deteriorates with time, the sensor output changes to the plus side on the high flow rate side and to the minus side on the low flow rate side.

As described above, if the tendency of the output change of the sensor after the element changes with time can be grasped in advance, it becomes possible to make correction. In the case of an embodiment of the present invention, since the sensor signal can be corrected by a function of the flow rate and the time, the logic of the following equation (1), which is a correction equation, is executed in the correction unit 310 to execute the correction processing. I do. Qa = Qb × (1 + f (Q, t)) (1) where Q is the flow rate, Qa is the flow rate after correction, Qb is the flow rate before correction, and t is the measurement time.

In the sensor output correction process, as shown in the flowchart of FIG. 2, after performing the normal correction calculation process (step 10), the time of the measurement timer is determined (step 1).
1). Then, in step 11, if a predetermined time t1 or more at which the influence of the aging deterioration becomes remarkable has elapsed, the aging correction calculation shown in equation (1) is performed (step 1).
2).

A specific method of the temporal correction calculation will be described with reference to the flowchart of FIG. 10 and the correction function graph of FIG.

The aging correction starts after a lapse of a predetermined time (t1 in this example). Since the correction coefficient f (Q, t) needs to be changed depending on the flow rate, the set value is changed for each representative flow rate. For example, when the flow rate is equal to or less than Q1 and up to Q1 + q1, the correction is made by the coefficient value using the correction coefficient represented by the expression a1 * t + b1 shown in FIG.

Similarly, at the flow rate of Q2 ± q2, although not shown in the figure, correction is made using the correction coefficient calculated by the function a2 * t + b2. Here, Q2-
The values of q1 and q2 are set such that a relationship of Q1 = q1 + q2 is established. The flow rate Q3 is an area where the correction coefficient is 0. Similarly, in the flow rate area of Q3 ± q3, the correction coefficient is 0, that is, there is no temporal correction.

When the flow rate is Q4 ± q4, a4
* Use t + b4. Here, since the coefficient in this area indicates a negative value, the coefficient value is subtracted as a correction result. A5 * when Q5 or more and Q5-q5
t + b5 is used as a coefficient.

In the case of the winding resistance type element which is the element of this example, the influence of the contamination considered as the deterioration of the characteristics of the sensor is caused by the attachment of contaminants to the sensor element itself. Since a certain amount or more cannot be adhered, it is almost constant where there is an influence of deterioration.

For this reason, by setting an upper limit value of the correction value in the correction processing, it is possible to prevent overcorrection in a region where no further correction is necessary.

That is, as shown in FIG.
In the following cases and in the case of Q1 + q1, the correction coefficient is a constant of F1. For other flow rates, correction constants F2, F3, F4, and F5 set similarly for each flow rate are used.

The above algorithm will be described with reference to the flowchart shown in FIG. The algorithm shown in FIG. 10 corresponds to the aging correction calculation unit in step 12 shown in FIG.
When the measurement time reaches t1 or more in step 11 of FIG.
Proceeding to step 12, the aging correction process is performed. Here, in step 61 of FIG. 10, it is further determined whether or not the elapsed time measured by the measurement timer is equal to or longer than t2. If the elapsed time is equal to or longer than t2, the process proceeds to step 62, and the aging correction using a constant coefficient (Qa = Qb + Fn, where , Fn are coefficients that vary with flow rate).

This is because, as described above, the element used in the present invention has a substantially constant value over a certain period of time.

If the elapsed time has not reached t2 or more in step 61 (if the elapsed time already determined in step 11 in FIG. 2 is not less than t1), the flow advances to step 63 to determine the range of the flow rate. I do. That is, Q1 ± q1, Q2
It is determined which of the flow ranges ± q2, Q3 ± q3, Q4 ± q4, and Q5 ± q5.

Here, a correction coefficient corresponding to the determined flow rate range is calculated, and a correction process is performed (step 64).

In the flow chart shown in FIG. 11, the flow points are represented by n and described as a single flow. However, in the example shown in FIG. Will show. The set flow point is 5
It is not limited to points, and even if it is more than 5 points,
Needless to say, the present invention can be applied to a small device.

As described above, by applying the present invention to the heating resistance type air flow meter, in the prior art, like the one characteristic at a certain flow point shown in FIG. Is about ± 4%, but within ± 2%, and the accuracy can be improved.

As described above, according to one embodiment of the present invention, the sensor is configured to measure the aging time during which the sensor is used, and to perform the correction operation for correcting the deterioration of the sensor in accordance with the aging time. .

Therefore, in a sensor having a numerical operation means and performing adjustment by digital data, a sensor with a built-in operation device capable of correcting deterioration over time and improving the accuracy of a sensor signal is realized. be able to.

In order to further increase the correction accuracy, a method may be considered in which a means for more accurately estimating a temporal change is considered. As a method, the operation time measurement is limited to only when the sensor output is equal to or more than a certain value. In this way, the influence of contamination, which is one of the deterioration with time, is large at a high flow rate. Therefore, the correction of the deterioration is performed by correcting the sensor output value corresponding to the high flow rate at a predetermined value V0 or more (for example, 4 V or more) In this configuration, the time is measured when is set, and the correction is performed only during the use time when the flow rate is high and the influence of the deterioration is large.

FIG. 4 shows a flowchart of time measurement for improving the correction accuracy. At step 30 in FIG. 4, it is determined whether or not the sensor output is equal to or higher than V0. After this, step 32
Is used to determine whether or not the power is off. This is because when the EEPROM is used as the means for storing the measured timer, the number of times of writing is limited, so that the storage of the measured result is limited only when the power is turned off, taking into consideration the case where the memory cannot be stored every time the timer is updated. It is assumed that this step 32 is not required.

Thereafter, in step 33, processing for storing the measurement result in the data storage means 400, which is a nonvolatile memory, is executed. When step 32 is omitted, the storage process is performed every time the timer is updated.

On the other hand, in order to simplify the system, instead of measuring the time during which the sensor is operating, a method of measuring the number of times the power is turned on and correcting deterioration with time can be considered.

FIG. 5 is an operation flowchart for measuring the number of times the power is turned on and performing the aging deterioration correction. In step 40 of FIG. 5, it is checked whether the power is turned on,
When it is determined that the power is turned on, a counter for measuring the number of times of power-on is operated in step 41. Then, the measurement result of the number of power-on times in step 41 is stored in the storage means in step 42.

Here, as shown in FIG. 4, whether to store the measurement result in the storage means when the power is turned off is determined.
It may be determined according to the type of the storage means to be used, and there is no problem in the configuration of either of them, so that it is omitted in the flowchart of FIG. In the following description as well, the description will be made in a state where it is omitted from the flowchart of the function description.

With this method, the same effect as when the operation time is measured and the aging correction is performed can be obtained. However, the same correction as when the operation time is measured can be simply implemented as a means. A method of measuring the number of power-on times when a certain period of time has elapsed since the power-on time is also conceivable.

FIG. 6 shows an operation flowchart for measuring when a predetermined time has elapsed since the power was turned on. The difference between this flowchart of FIG. 6 and the flowchart of FIG.
Therefore, instead of determining whether the power is turned on, it is determined whether or not a predetermined time T (for example, 30 minutes) has elapsed after the power is turned on. And store it in step 52.

According to the method shown in the flow chart of FIG. 6, even when the power supply is immediately turned off while using a simple method without measuring the operation time,
Correction in a situation closer to the use state is possible.

According to the method described above, a value corresponding to the time during which the sensor is used is measured, and the temporal correction shown in the above equation (1) is performed based on the data. The above equation (1) can be applied not only to the case of an arithmetic expression of a linear expression or higher, but also to the case of a correction constant as a fixed value.

That is, as shown in FIG.
(Q, t) is set as a constant that changes according to the duration, and the correction operation is performed without calculating the function. When the measurement time is equal to or longer than t1, F1 is used as a time-dependent correction term, and when it is longer than t2, time-dependent correction is performed using F2.

In this case, the number of correction terms set as constants is not limited to two types, and it is possible to set more than that. Also, the present invention can be applied to a sensor having a numerical operation unit having a low operation capability.

Although the correction constant shown in FIG. 7 is a constant correction value within the same period, the correction term varies depending on the flow rate value as described above. Therefore, by making the correction value that can be taken according to the flow rate variable within the same period, more accurate correction can be realized.

As a specific example, the correction value F1 shown in FIG.
Are set as F11, F12, F13, and F14 according to the flow rate value, and when correction is performed, a correction value is selected from the flow rate value at that time to perform correction processing. Similarly, a plurality of correction values can be set in the area F2.

Although the above-described example is an example in which the sensor with a built-in arithmetic device of the present invention is applied to a heating resistor type air flow measuring device, it can be applied to other measuring devices.

[0082]

According to the present invention, there is provided a numerical operation means,
In a sensor that performs adjustment based on digital data, deterioration with time can be corrected, and a sensor with a built-in arithmetic device that can improve the accuracy of a sensor signal can be realized.

That is, in a sensor with a built-in numerical operation whose initial accuracy has been improved by a digital multipoint adjustment, such as a heating resistor type air flow measuring device for measuring the flow rate of intake air flowing into an internal combustion engine, it is possible to correct the performance deterioration due to aging deterioration. Thus, it is possible to realize a sensor with a built-in arithmetic device that can continuously obtain high accuracy from the start of use to the service life.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of a heating resistor type air flow measuring device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a temporal correction algorithm of a sensor with a built-in arithmetic device according to an embodiment of the present invention.

FIG. 3 is a flowchart illustrating an algorithm for measuring the aging time of a sensor with a built-in arithmetic device according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating an algorithm of another method for measuring the aging time of the sensor with a built-in arithmetic device according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating an algorithm of still another method for measuring the aging time of a sensor with a built-in arithmetic device according to an embodiment of the present invention.

FIG. 6 is a flowchart illustrating an algorithm of still another method for measuring the aging time of the sensor with a built-in arithmetic device according to an embodiment of the present invention.

FIG. 7 is a graph illustrating a temporal correction constant setting value for explaining a temporal correction method for a sensor with a built-in arithmetic device according to an embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a partial cross section showing a state in which the heating resistor type air flow measuring device according to the embodiment of the present invention is attached to an intake pipe.

FIG. 9 is a circuit diagram showing a configuration of a conventional example for explaining a heating resistor type air flow measuring device according to an embodiment of the present invention.

FIG. 10 is a flowchart illustrating a correction portion of a temporal correction algorithm for a sensor with a built-in arithmetic device according to an embodiment of the present invention.

FIG. 11 is a graph showing a time-dependent correction coefficient for explaining a method for correcting the time-dependent correction of the sensor with the built-in arithmetic device according to the embodiment of the present invention.

FIG. 12 is a graph showing characteristics of a sensor with a built-in arithmetic device according to an embodiment of the present invention, in a case where a temporal correction is applied and in a case where it is not.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 air flow sensor 110 drive circuit 200 A / D conversion means 300 numerical calculation means 310 flow correction means 320 flow conversion means 330 communication means 390 operation time measurement means 400 data storage means 500 D / A conversion means RH heating resistor RC temperature sensitivity Resistor

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Onikawa 2477 Takaba, Hitachinaka City, Ibaraki Prefecture Inside Hitachi Car Engineering Co., Ltd. (72) Takayuki Saito 2477 Takaba Hitachinaka City, Ibaraki Prefecture Hitachi Car Corporation F term in engineering (reference) 2F035 AA02 EA05 EA09 3G084 BA04 DA22 EA05 EA11 EB12 FA00 FA08

Claims (13)

[Claims] 1. A sensor with a built-in arithmetic device having a numerical calculation means for correcting a measurement error, wherein: a time measuring means for measuring a cumulative time during which the sensor with a built-in arithmetic device functions or a time corresponding to the cumulative time; Correction means for correcting the output signal of the sensor when the time measured by the measurement means reaches a predetermined time to correct the output signal of the sensor; 2. The sensor according to claim 1, wherein the correction of the output signal of the sensor by the correction means is performed by a function corresponding to the accumulated time measured by the time measuring means or a value corresponding to the accumulated time. A sensor with a built-in arithmetic device, which is performed based on the following. 3. The sensor according to claim 1, wherein the correction of the output signal of the sensor by the correction means is performed in accordance with a cumulative time measured by the time measuring means or a value corresponding to the cumulative time. A sensor with a built-in arithmetic device, wherein the method is performed in two or more steps. 4. The sensor according to claim 1, wherein said time measuring means measures a time when an output signal of said sensor becomes equal to or higher than a predetermined voltage. 5. The sensor according to claim 1, wherein said time measuring means measures the number of times the sensor is turned on. 6. The sensor according to claim 5, wherein said time measuring means comprises:
A sensor with a built-in arithmetic device, which determines that the operation has been performed when a certain time has elapsed after supplying power to the sensor, and counts the number of times. 7. A heating resistor type air flow rate measuring device for measuring an air flow rate, comprising a sensor with a built-in calculating device having a numerical value calculating means for correcting a measurement error. Means for measuring the corresponding time; and correcting means for correcting the output signal of the sensor when the time measured by the time measuring means reaches a predetermined time to correct the output signal of the sensor. A heating resistor type air flow measuring device, characterized in that: 8. The heating resistor type air flow measuring device according to claim 7, wherein the correction of the output signal of the sensor by the correcting means corresponds to the accumulated time measured by the time measuring means or a value corresponding to the accumulated time. A heating resistor type air flow measuring device characterized in that the measurement is performed based on a function which performs the following. 9. A heating resistor type air flow measuring device according to claim 8, wherein said correction means corrects an output signal of said sensor by setting an upper limit value to said correction value. Flow measurement device. 10. The heating resistor type air flow measuring device according to claim 7, wherein the correction of the output signal of the sensor by the correcting means is performed by measuring the accumulated time measured by the time measuring means or a value corresponding to the accumulated time. A heating resistor-type air flow measurement device, wherein the measurement is performed based on a function of the determined air flow value. 11. The heating resistor type air flow measuring device according to claim 10, wherein the correction of the output signal of the sensor by the correcting means is performed in accordance with the accumulated time measured by the time measuring means or a value corresponding to the accumulated time. A heating resistor type air flow measuring device, wherein the correction method is changed over in two or more stages. 12. A heating resistor type air flow measuring device according to claim 10, wherein the correction of the output signal of said sensor by said correcting means is performed by a correction value determined by a function of the measured air flow value. Heating resistor type air flow measurement device. 13. The heating resistor type air flow measuring device according to claim 12, wherein the correction value is a correction value determined by switching a function of the air flow value in two or more steps. Resistor type air flow measurement device.