JP4460985B2 - Heating resistor type flow measuring device and control system using the same - Google Patents

Description

  The present invention relates to a heating resistor type flow rate measuring device for detecting the flow rate or flow rate of a fluid.

  A heating resistor type flow rate measuring device is widely used as a device for detecting a flow rate or a flow rate of a fluid based on a heat radiation phenomenon from a heating body to a fluid.

  In particular, measurement of the intake air flow rate of an internal combustion engine has been widely adopted due to advantages such as a wide measurement flow rate range and less influence of changes in temperature, pressure, and intake efficiency.

  On the other hand, the heating resistor type flow rate measuring device has a problem in the flow rate measurement accuracy in the pulsating flow. For example, as the pulsating flow amplitude increases, there is a problem that the flow rate average value measured by the heating resistor type flow rate measuring device is smaller than the true flow rate average value.

  This is considered to be caused by the fact that the relationship between the flow rate and the output of the heating resistor type flow rate measuring device is nonlinear in principle.

  In the prior art, the output voltage from the bridge circuit including the heating resistor and the temperature sensitive resistor is averaged by a hard filter, and the averaged signal is converted into an air flow rate.

  However, as described above, since the relationship between the flow rate and the output of the heating resistor type flow rate measuring device is nonlinear in principle, if the pulsation of the air flow rate occurs, the bridge circuit The output voltage average value decreased, and the voltage average value corresponding to the true air flow rate could not be obtained.

  Therefore, in order to reduce the error from the true air flow rate, in the technique described in Patent Document 1, linearization processing is performed on the output voltage from the bridge circuit including the heating resistor and the temperature sensitive resistor, and thereafter Then, the signal is averaged by a filter, and the signal subjected to the averaging process is non-linearized to be converted into an air flow rate.

JP 11-337382 A

  However, the reason why the voltage average value corresponding to the true air flow rate cannot be obtained is not only that the relationship between the flow rate and the output of the heating resistor type flow measuring device is nonlinear in principle, but also the heating resistor type flow rate. It is considered that there is also a response delay of the measuring device with respect to changes in the air flow rate.

This phenomenon will be described with reference to FIGS.
FIG. 8 is a diagram showing the relationship (flow rate output characteristics) between the air flow rate and the output voltage of a typical heating resistor type flow rate measuring device used for measuring the intake air flow rate of the internal combustion engine, and the output corresponding to the pulsating flow. Is shown.

  As a measuring means of the heating resistor type flow measuring device, a method of heating by directly supplying electric power (current) to the temperature sensitive resistor, or a method of indirectly heating by arranging a heating element in the vicinity of the temperature sensitive resistor Furthermore, there are various methods such as providing temperature sensing resistors on the upstream side and the downstream side of the fluid of the heating body and obtaining the flow rate from the temperature difference detected by the temperature sensing resistor. These measuring means basically detect the flow rate based on the amount of heat released to the fluid, and the flow rate output characteristic is not a straight line but a non-linear characteristic.

  For example, the relationship between the air flow rate and the heat dissipation amount (power for heating) of the temperature sensitive resistor is in principle a secondary characteristic, and the relationship between the flow rate and the heating current of the temperature sensitive resistor is theoretical. Has quaternary characteristics. As shown in FIG. 8, both have nonlinear characteristics with large output changes at low flow rates and small output changes at high flow rates.

  In pulsating flow measurement, an output corresponding to the flow rate that changes with time can be obtained. However, since the flow rate output characteristic is non-linear, the output has distortion with respect to the pulsating flow waveform as shown by the dotted line in FIG. At the same time, the waveform is reduced in amplitude.

  Further, in reality, there is a response delay due to a thermal response of the detection element, a control delay of the heating control circuit (drive circuit unit), etc., so that the output voltage waveform has a further reduced amplitude as shown by the solid line in FIG. . The average value of the air pulsating flow is the median value of the amplitude of the waveform, but the median value of the amplitude of the output voltage waveform is lower than the voltage output corresponding to the median value.

  That is, in the pulsating flow, the average value of the output voltage does not correspond to the average value of the air pulsating flow and shows a negative measurement error.

  In a control system using a general heating resistor type flow rate measuring device, the voltage output described above is converted into an air flow rate value by the control device. FIG. 9 is a graph showing the flow rate conversion, in which the output voltage is input to the control device on the horizontal axis, and the converted flow rate is shown on the vertical axis.

  Normally, since an input filter for the purpose of removing high-frequency electrical noise superimposed on wiring or the like is used at the input part of a control device such as an engine control unit, FIG. 9 shows the output of the flow measurement device (flow meter output) Is represented as a response delay caused by this input filter.

  In the description with reference to FIG. 8, it has been described that the output voltage has a response delay, but the response varies depending on the detection element and the heating control circuit. However, since the response delay cannot be eliminated completely, and the input filter may also cause a delay, the control device input has a response delay and a reduced amplitude waveform.

  The technique for linearization described in Patent Document 1 described above is obtained by converting the output voltage (first output) with a function that reverses the relationship between the air flow rate and the output voltage shown in FIG. Note that this conversion can be basically performed without a response delay if it is performed by calculation. The relationship between the converted output (second output) and the air flow rate is linear. Thus, if the relationship between the flow rate and the output is a straight line, a minus error of the average flow rate in pulsating flow measurement does not occur.

  However, actually, as shown in FIG. 8, a negative error occurs in the first output due to the fundamental nonlinear characteristic and response delay, and the second output obtained by converting the first output becomes the second output. Negative error.

  Therefore, as shown in FIG. 9, the flow rate of the pulsating flow converted by the control device has a smaller amplitude than the true flow rate, and the average flow rate is lower than the true value. Will have.

  An object of the present invention is to realize a heating resistor type flow rate measuring device capable of suppressing a negative flow rate measurement error at the time of pulsation of a measurement fluid due to nonlinearity of output voltage characteristics and a response delay, and a control system using the same. is there.

In order to achieve the above object, the present invention is configured as follows.
(1) The heating resistor type flow measuring device of the present invention measures the flow rate or flow velocity of the fluid based on the heat transfer phenomenon between the detection element and the fluid.

In the heating resistor type flow rate measuring device, the first output signal whose output characteristic with respect to the flow rate or flow velocity is non-linear is opposite to the linear type in which the output signal and the air flow rate are proportional to each other. into a second output signal having a non-linear characteristic as a relationship, and a flow rate signal value conversion unit for outputting a second output signal after the conversion as a flow rate signal.

(2) In the above (1), the flow rate signal value conversion unit, the amplitude value of the first output signal as a large, after the response advancing correction quicken the responsiveness of the first output signal, the The characteristic- converted second output signal is output as a flow rate signal.

(3) In addition, preferably, in the above SL (2), the flow rate signal value conversion unit decreases the amplitude value of the second output signal, the response delay correction to delay the response of the second output signal After that, it outputs as a flow rate signal.

(4) Further, preferably, the (1), (2), said second output signal, varies as the low flow rate smaller to flow, non-linear characteristics that change becomes greater as becomes high flow Have

(5) Preferably, in the above (3), the second output signal has a non-linear characteristic in which the change is smaller as the flow rate is lower than the flow rate, and the change is increased as the flow rate is increased .

  (6) The flow rate control system of the present invention uses a heating resistor type flow rate measuring device that measures the flow rate or flow velocity of the fluid based on the heat transfer phenomenon between the detection element and the fluid, and controls the flow rate and the mixing ratio. And so on.

The flow rate control system inputs a first output signal whose output characteristic with respect to the flow rate of the heating resistor type flow rate measuring device is a non-linear characteristic, and for the linear type in which the output signal and the air flow rate are proportional to each other. , into a second output signal having a non-linear characteristic as the opposite tendency each other, with a flow rate signal value conversion unit for outputting a second output signal after the conversion as a flow rate signal, the second output signal Control operation is performed based on this .

(7) Preferably, in the above (6), the flow rate signal value conversion unit, the amplitude value of the first output signal as a large, after the response advancing correction quicken the responsiveness of the first output signal, the outputting a second output signal characteristic conversion as a flow rate signal.

(8) Further, preferably, in the above (7), the flow rate signal value conversion unit decreases the amplitude value of the second output signal, after the response delay correction to delay the response of the second output signal And output as a flow rate signal.

(9) Preferably, in the above-mentioned (6) or (7), said second output signal, varies as the low flow rate smaller to flow, non-linear characteristics that change becomes greater as becomes high flow Have

(10) Preferably, in the above (8), the second output signal has a non-linear characteristic such that the lower the flow rate, the smaller the change and the greater the flow rate.

  (11) The heating resistor type flow measuring device of the present invention has the heating resistor 3 arranged at the position where the fluid for measuring the flow rate flows, and the first voltage signal generated according to the current flowing through the heating resistor 3 Based on V1, the flow rate Q of the fluid is measured.

  The heating resistor type flow rate measuring device of the present invention includes a flow rate signal value converting means 1b, and the flow rate signal value converting means 1b is a first correspondence relationship showing the relationship between the first voltage signal V1 and the fluid flow rate Q. When the relationship between the first voltage signal V1 and the fluid flow rate Q is a proportional relationship, the equation is symmetrical with respect to the linear equation representing the first voltage signal V1 and the fluid flow rate Q. Convert to the second relational expression.

  Then, the first voltage signal V1 is converted into the second voltage signal V2 based on the converted second relational expression, and a fluid flow rate signal is generated based on the converted voltage signal.

  (12) Preferably, in the above (11), further provided is a first response correcting means 1c for amplifying the first voltage signal V1 generated according to the current Ih flowing through the heating resistor 3.

  The first voltage signal V1 ′ corrected by the first response correction unit 1c is supplied to the flow rate signal value conversion unit 1b.

  (13) Preferably, in the above (12), further provided is a second response correction unit 1d that decreases the amplitude value of the flow rate signal output from the flow rate signal value conversion unit 1b.

  (14) A control system for an internal combustion engine according to the present invention controls a fuel injection amount to the internal combustion engine based on an air flow rate signal supplied from the internal combustion engine, an engine speed signal, and a throttle valve opening signal.

  The control system for an internal combustion engine of the present invention includes the heating resistor type flow rate measuring device 1 and the control device 2 shown in (11) above.

  The controller 2 supplies the fuel injection amount to the fuel injection valve 60 based on the air flow rate signal Q from the heating resistor type flow rate measuring device 1, the internal combustion engine speed signal Ne, and the throttle valve opening signal TV. And an output means 2c for supplying a signal corresponding to the fuel injection amount calculated by the calculation means 2b to the fuel injection valve 60.

  According to the present invention, it is possible to realize a heating resistor type flow rate measuring device capable of suppressing a negative flow rate measurement error at the time of pulsation of a measured fluid due to nonlinearity of output voltage characteristics and response delay, and a control system using the same. it can.

  Because the negative error during pulsation can be corrected with the same output flow characteristics and responsiveness as the cause of the pulsation, it is possible to measure more accurately than the error reduction by the conventional sub-passage, and the non-conformance of correction due to pulsation state change is reduced. It is possible to realize a heating resistor type flow rate measuring device or control system capable of high-precision measurement under a wide range of pulsation conditions.

  In addition, since error correction during pulsation can be omitted from the configuration conditions of the sub-passage, the structure of the sub-passage can be simplified and miniaturized, and a low-cost heating resistor type flow measurement device can be realized. It becomes possible.

  The auxiliary passage can be configured to improve performance and reliability other than the measurement error reduction of pulsating flow, and it is possible to achieve a highly reliable heating resistor type flow measurement device with excellent performance. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2 are explanatory views of the principle of the present invention. Prior to explaining the principle of the present invention, the operation principle of the heating resistance type air flow rate measuring device will be described with reference to FIG.

  FIG. 7 is a schematic configuration diagram of the drive circuit unit 1 a of the heating resistor type air flow measuring device 1. The driving circuit of the heating resistor type air flow rate measuring device 1 is roughly divided into a bridge circuit and a feedback circuit.

  In order to measure the intake air flow rate, the heating resistor RH arranged in the air passage 4, the temperature sensitive resistor RC for compensating the temperature of the intake air Q, and the resistors R10, R11 arranged outside the air passage 4. A bridge circuit is formed. The heating resistor RH and the resistor R10 are connected in series with each other, and the temperature sensitive resistor RC and the resistor R11 are connected in series with each other. The heating resistor RH and resistor R10 and the temperature sensitive resistor RC and resistor R11 are connected in parallel to each other.

  Then, the operational amplifier OP1 that receives the potentials of the resistors R10 and R11 is used, and the output of the operational amplifier OP1 is supplied to the base of the transistor Tr. The collector of the transistor Tr is connected to a voltage source, and the emitter is connected to the heating resistor RH and the temperature sensitive resistor RC.

  An operational amplifier OP1 causes a heating current Ih to flow through the heating resistor RH so that a constant temperature difference is maintained between the heating resistor RH and the temperature sensitive resistor RC while applying feedback, and an output signal V1 (resistance) according to the air flow rate. R10 potential) is output.

  That is, when the air flow rate is high, a large amount of heat is taken from the heating resistor RH, so that a large heating current Ih is passed. On the other hand, when the air flow rate is slow, the amount of heat taken away from the heat generating resistor RH is small, so that the heating current Ih can be reduced. By using this heating current Ih, an output signal corresponding to the air flow rate (flow rate) can be obtained.

  The first output voltage V1 of the drive circuit unit 1a is converted into an output voltage V2 that becomes a conversion characteristic curve C1 as shown in FIG.

  FIG. 2 is a graph for explaining the relationship between the first output voltage V1 and the second output voltage V2 with respect to the air flow rate Q. The horizontal axis is the air flow rate, and the vertical axis is the output voltage value (flow rate signal).

  In FIG. 2, a curve indicated by a broken line and a white circle is a first output signal V1 and an air flow rate curve (first correspondence relationship), and a curve indicated by a solid line and a black circle is a second output signal V2 and an air flow rate curve (second Of the corresponding relationship). The output signal V1 curve and the output signal V2 curve have a symmetric relationship with respect to the straight line L (a linear expression that can be expressed in a proportional relationship when the output voltage signal and the air flow rate are in a proportional relationship). is doing.

  That is, the technique described in Patent Document 1 converts the first output signal V1 to be a straight line L and obtains a flow rate signal. However, in the first embodiment of the present invention, The output signal V1 is converted into a second output signal V2 having characteristics that are symmetric with respect to the straight line L with respect to the first output signal V1 (inverse nonlinear conversion).

  As a result, not only the nonlinearity of the output voltage characteristic in the heating resistor type flow rate measuring device but also a negative flow rate measurement error at the time of pulsation of the measurement fluid due to a response delay can be suppressed.

  Note that the first correspondence relational expression and the linear expression that can be expressed by the proportional relation described above are experiments for the relationship between the actual flow rate of the fluid to be measured and the first output voltage signal in each heating resistor type flow rate measuring device. Can be calculated in advance.

  Therefore, the second correspondence relation expression can be calculated from the first correspondence relation expression and the linear expression calculated in advance.

  FIG. 3 is a schematic configuration diagram when the heating resistor type air flow measuring device 1 according to the first embodiment of the present invention is used in a control system of an internal combustion engine. In addition, this 1st Embodiment is an example which suppresses the measurement error by the nonlinearity of the flow volume output characteristic in flow volume measurement, the thermal response delay of a detection element, and the control delay of a heating control circuit (drive circuit part).

  In FIG. 3, an output voltage V1 corresponding to the heating current flowing through the heating resistor 3 disposed in the air passage 4 is output from the drive circuit unit 1a. This output voltage V1 is supplied to the flow rate signal value converter 1b and converted to a second output voltage V2 having a characteristic curve shown in FIG.

  The converted second output voltage V2 is supplied to the input circuit 2a of the engine control unit 2 as an air flow rate signal. The input circuit 2a is also supplied with an engine throttle valve opening signal TV and an engine speed signal Ne. These input signals are converted into appropriate digital signals and supplied to the CPU 2b.

  The CPU 2b calculates the fuel injection amount to be supplied to the injector based on the air flow rate signal Q, the throttle valve opening signal TV, and the engine speed signal Ne supplied from the input circuit 2a. The calculated fuel injection amount is supplied from the CPU 2b to the injector as the fuel injection amount signal Tp via the output circuit 2c.

  As described above, according to the first embodiment of the present invention, the heating resistance that can suppress the negative flow rate measurement error at the time of the pulsation of the measurement fluid due to the nonlinearity of the output voltage characteristic of the drive circuit unit 1a and the response delay. A body flow measuring device can be realized.

  Here, in the first embodiment, the response delay is an example in which the thermal response delay of the detection element and the control delay of the heating control circuit (drive circuit unit) are considered, but the engine control unit (control device) 2 The input unit may be provided with an input filter for the purpose of noise removal, and a response delay due to the input filter may have to be taken into consideration.

  FIG. 4 is a schematic configuration diagram when the heating resistor type air flow rate measuring apparatus 1 according to the second embodiment of the present invention is used in an internal combustion engine control system. The second embodiment is an example in which the response delay due to the input filter described above is also taken into consideration.

  The difference between the second embodiment and the first embodiment is that in the second embodiment, a response correction unit 1c is arranged between the drive circuit unit 1a and the flow rate signal value conversion unit 1b. In other respects, the first and second embodiments have the same configuration.

  In FIG. 4, the first output voltage V1 output from the drive circuit unit 1a is supplied to a response correction unit (advance correction) 1c. In this response correction unit 1c, the voltage V1 is converted into a response correction voltage V1 ′ (broken line) having an amplitude value larger than that of the voltage V1 in order to correct a response delay caused by the noise removal input filter of the control unit 2. .

  The response correction voltage V1 ′ is supplied to the flow rate signal value conversion unit 1b, and is converted into a second output voltage V2 having an inverse nonlinear characteristic (a characteristic that is symmetric with respect to the straight line L) with the response correction voltage V1 ′. .

  The second output voltage V2 is supplied to the engine control unit 2 and subjected to signal processing similar to that of the first embodiment.

  As described above, according to the second embodiment of the present invention, not only the non-linearity of the output voltage characteristic of the drive circuit unit 1a and the negative flow rate measurement error during the pulsation of the measured fluid due to the response delay, but also the heating resistance It is possible to realize a heating resistor type flow rate measuring device capable of suppressing a minus flow rate measurement error due to a response delay by the noise removal filter of the body type flow rate measuring device.

  Here, in the second embodiment, the second output voltage V2 from the flow rate signal value conversion unit 1b is corrected for a minus error with respect to the average value during air flow pulsation. Therefore, if the average value is the same, changing the amplitude value will not affect the control result.

  Therefore, it is preferable that the output signal of the heating resistor type air flow rate measuring device 1 is an amplitude value that allows the engine control unit 2 to easily perform arithmetic processing.

  FIG. 5 is a schematic configuration diagram when the heating resistor type air flow measuring device 1 according to the third embodiment of the present invention is used in a control system of an internal combustion engine. As described above, the third embodiment is an example in which the output signal of the heating resistor type air flow measuring device 1 is set to an amplitude value that allows the engine control unit 2 to easily perform arithmetic processing.

  In the third embodiment, a response correction unit (delay correction) 1d that reduces the amplitude value of the output signal V2 from the flow signal value conversion unit 1b to V2 ′ (broken line) is disposed. Other configurations are the same as those of the second embodiment.

  The second output voltage V2 ′ from the response correction unit (delay correction) 1d is supplied to the engine control unit 2 and subjected to signal processing similar to that of the second embodiment.

  As described above, according to the third embodiment of the present invention, not only the non-linearity of the output voltage characteristic of the drive circuit unit 1a and the negative flow rate measurement error during the pulsation of the measured fluid due to the response delay, but also the heating resistance It is possible to realize a heating resistor type flow rate measuring device that can suppress a minus flow rate measurement error due to a response delay by the noise removal filter of the body type flow rate measuring device and that can be easily processed by the engine control unit.

  FIG. 6 is a diagram showing a specific configuration example of an electronic fuel injection type internal combustion engine using the heating resistor type flow rate measuring device of the present invention.

  In FIG. 6, the intake air 67 sucked from the air cleaner 54 is an intake having a body 53, a suction duct 55, a throttle body 58, and an injector (fuel injection valve) 60 to which fuel is supplied. The air is sucked into the engine cylinder 62 through the manifold 59.

  The gas 63 generated in the engine cylinder 62 is discharged to the outside through the exhaust manifold 64.

  The air flow rate signal output from the circuit module 52 of the heating resistance type air flow rate measuring device, the intake air temperature signal from the intake air temperature sensor 51, the throttle valve angle signal output from the throttle angle sensor 57, and the exhaust manifold 64 are provided. The oxygen concentration signal output from the oxygen concentration meter 65 and the engine rotation speed signal output from the engine rotation speed meter 61 are supplied to the control unit 66.

  The control unit 66 sequentially calculates the supplied signal to obtain an optimal fuel injection amount and an idle air control valve opening, and controls the injector 60 and the idle control valve 56 using these values.

  If the heating resistance type air flow rate measuring device according to the present invention is used in an electronic fuel injection type internal combustion engine, an accurate air flow rate can be measured and an accurate operation control of the internal combustion engine can be performed.

  In the above-described example, the present invention is applied to a heating resistance type flow rate measuring device that measures the air flow rate. However, the present invention measures not only the air flow rate but also the flow rate of other fluids. It is also applicable to cases.

It is a principle explanatory drawing of the present invention, and is a figure explaining reverse nonlinear transformation. It is a principle explanatory drawing of the present invention, and is a figure explaining reverse nonlinear transformation. It is a schematic block diagram at the time of using the heating resistor type air flow measuring device 1 which is the 1st Embodiment of this invention for the control system of an internal combustion engine. It is a schematic block diagram at the time of using the heating resistor type air flow measuring device 1 which is the 2nd Embodiment of this invention for the control system of an internal combustion engine. It is a schematic block diagram at the time of using the heating resistor type air flow measuring device 1 which is the 3rd Embodiment of this invention for the control system of an internal combustion engine. It is a figure which shows the example of a specific structure of the internal combustion engine of the electronic fuel injection system using the heating resistor type flow measuring device of the present invention. It is a schematic block diagram of the drive circuit part of the heating resistor type air flow measuring device of the present invention. It is a figure which shows the flow volume versus output characteristic of a heating resistor type flow measuring device. It is a figure explaining the delay by the input filter in a control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating resistor type air flow measuring device 1a Drive circuit 1b Flow rate signal value conversion part 1c Response correction part (advance correction)
1d Response correction unit (delay correction)
2 Engine control unit 2a Input circuit 2b CPU
2c Output circuit 3 Heating resistor 4 Air passage

Claims (14)

In the heating resistor flow measurement device that measures the flow rate or flow rate of the fluid based on the heat transfer phenomenon between the detection element and the fluid,
The first output signal whose output characteristic with respect to the flow rate or flow velocity is a non-linear characteristic has a non-linear characteristic in which the output signal and the air flow rate have a non-linear characteristic that is in a reverse tendency relationship with respect to a linear expression in which the output signal and the air flow rate are in a proportional relationship A heating resistor type flow rate measuring device comprising a flow rate signal value conversion unit that converts the output signal into a flow rate signal and converts the converted second output signal as a flow rate signal . The heating resistor type flow rate measuring device according to claim 1, wherein the flow rate signal value conversion unit increases the amplitude value of the first output signal , and after the response advance correction that accelerates the response of the first output signal , A heating resistor type flow rate measuring apparatus that outputs the second output signal obtained by converting the characteristics as a flow rate signal. 3. The heating resistor type flow rate measuring device according to claim 2, wherein the flow rate signal value conversion unit decreases the amplitude value of the second output signal and corrects the response delay of the second output signal after delaying response . A heating resistor type flow rate measuring device that outputs a flow rate signal. In the thermal type flow measuring device according to claim 1 or 2, wherein the second output signal is significant enough low flow rate smaller to flow, have a non-linear characteristics that change becomes greater as becomes high flow Heating resistor type flow rate measuring device characterized by 4. The heating resistor type flow rate measuring apparatus according to claim 3, wherein the second output signal has a non-linear characteristic in which the change is smaller as the flow rate is lower than the flow rate, and the change is increased as the flow rate is increased. Heating resistor type flow measuring device. In the flow rate control system that controls the flow rate and the mixing ratio using a heating resistor type flow rate measuring device that measures the flow rate or flow rate of the fluid based on the heat transfer phenomenon between the detection element and the fluid,
The first output signal whose output characteristic with respect to the flow rate of the heating resistor type flow rate measuring device is a non-linear characteristic is inputted, and the linear relationship in which the output signal and the air flow rate are proportional to each other has an inverse tendency relationship with each other. And a flow rate signal value conversion unit for converting the converted second output signal into a second output signal having a non-linear characteristic and outputting the converted second output signal as a flow rate signal, and performing a control operation based on the second output signal. A flow control system characterized by that. 7. The flow rate control system according to claim 6, wherein the flow rate signal value conversion unit increases the amplitude value of the first output signal and corrects the characteristic after the response advance correction that accelerates the response of the first output signal. flow control system and outputs a second output signal as a flow rate signal. 8. The flow rate control system according to claim 7, wherein the flow rate signal value conversion unit reduces the amplitude value of the second output signal and corrects the response delay of the second output signal as a flow rate signal after delaying the response delay. A flow rate control system characterized by output. According to claim 6 or 7 flow control system, wherein the second output signal is significant enough low flow rate smaller to flow, and characterized by having a non-linear characteristics that change becomes greater as becomes high flow To flow control system. 9. The flow rate control system according to claim 8, wherein the second output signal has a non-linear characteristic in which the change is smaller as the flow rate is lower than the flow rate, and the change is larger as the flow rate is higher. A heating resistor type flow measuring device having a heating resistor arranged at a position where a fluid for measuring a flow rate flows, and measuring the flow rate of the fluid based on a first voltage signal generated according to a current flowing through the heating resistor. In
The first correspondence signal indicating the relationship between the first voltage signal and the fluid flow rate, and the first voltage signal and the fluid when the relationship between the first voltage signal and the fluid flow rate is a proportional relationship. A linear expression representing the flow rate is converted into a second relational expression that is symmetrical with each other, and the first voltage signal is converted into a second voltage signal based on the second relational expression, and converted. A heating resistor type flow rate measuring device comprising flow rate signal value converting means for generating a flow rate signal of a fluid based on the voltage signal.   12. The heating resistor type flow rate measuring device according to claim 11, further comprising a first response correcting means for amplifying a first voltage signal generated according to a current flowing through the heating resistor, and the first response correcting means corrects the first voltage signal. The heating resistor type flow rate measuring device, wherein the first voltage signal thus supplied is supplied to the flow rate signal value converting means.   13. A heating resistor type flow rate measuring apparatus according to claim 12, further comprising second response correction means for reducing the amplitude value of the flow rate signal output from the flow rate signal value converting means. apparatus. In a control system for an internal combustion engine that controls the fuel injection amount to the internal combustion engine based on an air flow rate signal supplied from the internal combustion engine, a rotation speed signal of the internal combustion engine, and a throttle valve opening signal,
A first corresponding relational expression showing a relationship between a heating resistor disposed at a position where air flows, a first voltage signal generated according to a current flowing through the heating resistor, and an air flow rate is represented by the first voltage signal. When the relationship between the air flow rate and the air flow rate is a proportional relationship, the linear equation representing the first voltage signal and the air flow rate is converted to a second relational equation that is symmetrical to each other. A heating resistor type flow rate measuring device having flow rate signal value conversion means for converting a first voltage signal into a second voltage signal based on the relational expression and generating a flow rate signal of air based on the converted voltage signal When,
Calculation means for calculating the fuel injection amount to be supplied to the fuel injection valve based on the air flow rate signal from the heating resistor type flow rate measuring device, the engine speed signal, and the throttle valve opening signal, and the calculation means A control device having output means for supplying the fuel injection valve with a signal corresponding to the fuel injection amount calculated by
An internal combustion engine control system comprising:

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