JP2007101315A - Fuel consumption operational device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel consumption operational device of a vehicle capable of calculating stabilized fuel consumption information with sufficient responsibility by reducing response delay required to the signal stabilizing treatment, while preventing noises contained in fuel injection quantity information used for the calculation of fuel consumption information. <P>SOLUTION: The fuel consumption operational device calculating fuel consumption at each pre-set operation period on the basis of fuel injection quantity information to an internal-combustion engine on-board is equipped with a running mean means 102 implementing running mean processing of fuel injection quantity information and a filtering means 103 implementing low-pass filter processing of the output from the running mean means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel consumption calculation device for a vehicle that calculates fuel consumption for each preset calculation cycle based on fuel injection amount information to an internal combustion engine.

For example, in a vehicle that is required to travel at a good fuel consumption rate, such as a large truck, the travel distance per unit fuel consumption or per unit travel distance every short time (for example, about several seconds) A technique for calculating and displaying fuel consumption information such as fuel consumption in real time has been proposed and put into practical use (see, for example, Patent Document 1).
In this way, if the fuel consumption information of the vehicle for each short period is displayed in real time, the driver refers to the displayed fuel consumption information, predicts the optimum traveling speed for traveling with good fuel consumption, The traveling speed can be adjusted, which is very effective for improving the fuel consumption when the vehicle is traveling.

In recent years, as common rail technology has been put to practical use, it has become possible to electronically control the fuel injection amount even in vehicles equipped with diesel engines, which are often used for heavy trucks, etc. To be able to grasp.
Such calculation of fuel consumption information is performed based on fuel injection amount information set by a fuel injection amount setting unit of an electronic control unit (ECU) of the engine.
JP 2002-166749 A

However, the fuel injection amount information (fuel injection amount signal) includes a lot of minute fluctuations (that is, noise) (see FIG. 5). In particular, since the diesel engine generally has a large increase / decrease in the fuel injection amount as compared with the gasoline engine, the fuel injection amount information includes a lot of noise.
For this reason, if the ECU directly uses the fuel injection amount signal for calculation of fuel consumption information, the fuel consumption information calculated due to the influence of noise or the like will vary and become unstable. The fuel consumption information is calculated after the signal is stabilized by performing a filtering process on the fuel injection amount signal with the filter coefficient.

For this filtering process, a first-order recursive low-pass filter (LPF) is used, and the LPF performs a filter operation based on a predetermined filter coefficient every predetermined operation period (for example, 20 milliseconds).
In the LPF, filter coefficients a and b satisfying (a + b = 1, a> 0, b> 0) are set, and the input signal (pre-filter signal) L ₀ (n) and the LPF one calculation cycle before There calculated filter after the signal F _{0 (n-1)} and the filter coefficients a, and calculates the filter after the signal F0 (n) by adding a material obtained by multiplying b respectively [i.e., F ₀ (N) = aL ₀ (n) + bF ₀ (n−1)].

As a result, the noise (small change) included in the pre-filter signal is cut or suppressed by the filter processing by the LPF, and the post-filter signal has smooth fluctuation characteristics.
Note that the post-filter signal filtered by the LPF is cumulatively affected by the pre-filter signal in each previous period, but this effect is greater for the pre-filter signal closer to that point, and from that point onwards. The far pre-filter signal becomes smaller.

At this time, the value of the filter coefficient b multiplied by the filtered signal F ₀ (n−1) before one calculation cycle is increased [the value of the filter coefficient a multiplied by the input signal L ₀ (n) is decreased] (filter Since the noise in the input signal L ₀ (n) in the calculation cycle is more strongly suppressed in the calculated filtered signal, even noise with a large amplitude can be sufficiently suppressed.

However, if the value of the filter coefficient a is reduced in this way, the latest input signal L ₀ (n) is neglected. For example, the pre-filter signal L ₀ (n) changes greatly as shown in FIG. In this case, the response delay ΔT until the fluctuation of the pre-filter signal is reflected in the value of the post-filter signal becomes large.
On the contrary, if the value of the filter coefficient a is set large (the value of the filter coefficient b is made small) (also referred to as making the filter lighter), the response delay ΔT can be reduced, but if the noise amplitude is large, the noise The fuel consumption information calculation by the ECU becomes unstable.

Therefore, when the noise is suppressed by filtering the fuel injection amount signal, the values of the filter coefficients a and b are as much as possible while suppressing the response delay within the allowable range with respect to the change of the fuel injection amount information. It is desirable to set the value so that noise can be suppressed above a certain level.
However, according to the conventional technology, noise with a large amplitude is included in the fuel injection amount information. Therefore, if the signal stabilization process is performed so as to remove this noise, the response delay of the fuel injection amount information after the stabilization process is large. Thus, it is difficult to simultaneously suppress noise and avoid response delay. And if the response delay of the fuel injection amount after signal stabilization becomes large, for example, the display of fuel consumption information will be delayed, and the driver will not be in good fuel consumption state in reality. It is conceivable that the vehicle is erroneously judged to be in a good driving state and actually travels with a fuel consumption that is not good, and the fuel consumption may worsen.

  The present invention was devised in view of such problems, and can sufficiently suppress noise included in the fuel injection amount information used for calculation of fuel consumption information, and at the same time reduce response delay for signal stabilization processing, It is an object of the present invention to provide a vehicle fuel consumption calculation device capable of calculating stable fuel consumption information with good responsiveness.

  In order to achieve the above-described object, a fuel calculation device for a vehicle according to a first aspect of the present invention provides fuel efficiency at a predetermined calculation cycle based on fuel injection amount information to an internal combustion engine mounted on the vehicle. The fuel consumption calculation device to be calculated is characterized by comprising moving average means for moving average processing the fuel injection amount information and filter means for low pass filter processing the output of the moving average means.

According to a second aspect of the present invention, there is provided the vehicle fuel arithmetic apparatus according to the first aspect, wherein the moving average means performs the calculation of r-1 consecutive times input up to the previous time every calculation period. The moving average process is performed based on the fuel injection amount information for a period and the fuel injection information for the current calculation period.
According to a third aspect of the present invention, there is provided a fuel calculation device for a vehicle according to the first or second aspect, wherein the filter means performs low-pass filter processing on the output of the moving average means for each calculation period. The output value F (n) output from the filter unit in the calculation cycle n, the input value L (n) input to the filter unit in the calculation cycle n, and the calculation cycle (one calculation cycle before) The output value F (n-1) output from the filter means in n-1) is F (n) = aL (n) + bF (n-1), where a + b = 1, a> 0, b It is characterized by satisfying a relationship of> 0.

According to a fourth aspect of the present invention, there is provided the vehicle fuel calculation device according to the second or third aspect, wherein the calculation period is 10 to 40 milliseconds, and the predetermined number r is 25 to 100. It is characterized by being.
According to a fifth aspect of the present invention, there is provided a fuel calculation device for a vehicle according to the present invention, wherein the internal combustion engine is a diesel engine.

According to the fuel consumption calculation apparatus of the present invention as set forth in claim 1, since the fuel injection amount information is moved and averaged by the moving average means to reduce noise contained in the fuel injection amount information, the output of the moving average means is filtered. Therefore, when performing the low-pass filter processing, it is possible to set the filter coefficient with an emphasis on responsiveness, and it is possible to obtain a good responsiveness while reliably suppressing noise included in the fuel injection amount information.
According to the fuel consumption calculation apparatus of the present invention as set forth in claim 2, in addition to the effect of claim 1, the moving average means calculates r−1 consecutive calculations input up to the previous time every calculation cycle. Outputs an average value of fuel injection amount information for a total of r calculation cycles of fuel injection amount information for the cycle and fuel injection amount information for the current calculation cycle, thus reducing noise contained in the fuel injection amount information can do.

According to the fuel consumption calculation apparatus of the present invention, the fuel injection amount included in the fuel injection amount information can be obtained by appropriately setting the filter coefficients a and b in addition to the effect of the first or second aspect. Good responsiveness can be obtained while reliably suppressing noise included in information.
Further, according to the fuel consumption calculation apparatus of the present invention as set forth in claim 4, in addition to the effects of claims 1 to 3, the cycle of the calculation cycle is set to 10 to 40 milliseconds, and the predetermined cycle number r is set to 25 to 100. By setting, it is possible to obtain good responsiveness while reliably suppressing noise included in the fuel injection amount information included in the fuel injection amount information.

  Further, according to the fuel consumption calculation device of the present invention described in claim 5, in addition to the effects of claims 1 to 4, the response in a diesel engine that requires a particularly good fuel consumption performance while the change in the fuel injection amount is large. The fuel efficiency calculation can be performed with good performance.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 are diagrams for explaining a vehicle fuel consumption calculation device according to an embodiment of the present invention. FIG. 1 is a block diagram showing the overall configuration of the fuel consumption calculation device, and FIG. FIG. 3 is a graph schematically showing an example of a change over time of a fuel injection amount signal and a signal obtained by performing signal stabilization processing in the present embodiment. .

In this embodiment, the fuel consumption calculation device of the present invention is applied to a diesel engine-equipped vehicle that electronically controls the optimal fuel injection amount in accordance with the driving state of the vehicle.
As shown in FIG. 1, the fuel consumption calculation device according to the present embodiment includes an ECU (electronic control device) 1, a vehicle speed sensor 2, and a display device (display means) 3 including a memory (ROM, RAM) and a CPU. The vehicle speed sensor 2 is connected to the input side of the ECU 1, and the display device 3 is connected to the output side of the ECU 1.
The vehicle speed sensor 2 inputs vehicle travel speed information [vehicle speed signal V (n)] to the ECU 1 every one calculation cycle (here, the time of one calculation cycle is 20 milliseconds). Note that the input and calculation of all the values described below are performed at every calculation cycle.

The display means 3 is configured to display the fuel efficiency information output from the ECU 1 so as to be visible to the driver.
The ECU 1 includes a fuel injection amount setting unit 101, a moving average calculation unit (moving average unit) 102, a fuel injection amount LPF (filter unit) 103, a fuel consumption calculation unit 104, an upper limit value limiter 105, and fuel consumption information LPF 106 as functional elements. ing.

The fuel injection amount setting unit 101 sets an optimal fuel injection amount based on the driving state of the vehicle, and sends a fuel injection command signal to a fuel injection valve (not shown). The fuel injection amount setting unit 101 outputs a fuel injection amount signal X (n) as fuel injection amount information to the moving average calculation unit 102 based on the set fuel injection amount.
The fuel injection amount signal X (n) is a fuel injection amount [unit: L / h] per unit time (here, 1 hour). Further, the fuel injection amount setting unit 101 may be provided in an ECU separate from the ECU 1, and the ECU 1 may be configured to receive the information (fuel injection amount information).
The moving average calculation unit 102 performs a moving average process on the input fuel injection amount signal X (n), calculates a moving average signal L (n), and outputs it to the fuel injection amount LPF 103. Predetermined filter coefficients a and b (where a> 0, b> 0, a + b = 1) are set in advance in the fuel injection amount LPF 103, and the input moving average signal L (n) is filtered. The filtered signal F (n) is calculated and input to the fuel consumption calculation unit 104. In the present embodiment, in the moving average calculation unit 102 and the fuel injection amount LPF 103, a signal is provided so that the delay in response to noise suppression is sufficiently reduced while the noise included in the fuel injection amount signal X (n) is reliably suppressed. Stabilization processing is performed. Details of the signal stabilization processing in the moving average calculation unit 102 and the fuel injection amount LPF 103 will be described later.

A vehicle speed signal V (n) is input from the vehicle speed sensor 2 together with the post-filter signal F (n) to the fuel consumption calculation unit 104. In the fuel consumption calculation unit 104, the vehicle speed signal V (n) [km / H] is divided by the filtered signal F (n) [L / h] to calculate a fuel efficiency information signal P (n) [km / L] indicated as a travel distance per liter of fuel [that is, P (N) = V (n) / F (n)].
The upper limit value limiter 105 compares the input fuel efficiency information signal P (n) with a predetermined upper limit value M, and the input fuel efficiency information signal P (n) is greater than the upper limit value M. When the value is large [that is, when P (n)> M], the value of the fuel efficiency information signal P (n) is set to the upper limit value M. Thus, the upper limit value limiter 105 limits the upper limit value of the fuel efficiency information signal P (n) to the upper limit value M or less.

  Explaining this reason, when the fuel injection amount in the period corresponding to the calculation cycle is 0 or close to 0, the calculated fuel consumption information signal P (n) becomes an abnormally large value. If such an abnormal value is included in the fuel efficiency information, the accuracy of the fuel efficiency information is impaired. In order to avoid this, in this embodiment, an upper limit value limiter 105 is provided, and the fuel efficiency information signal P (n) becomes an abnormal value. In this case, the fuel consumption information signal P (n) is limited so as not to exceed the predetermined upper limit value M.

  Incidentally, in the above-mentioned moving average calculation unit 102 and fuel injection amount LPF 103, noise included in the fuel injection amount signal X (n) is sufficiently suppressed, but on the other hand, it is input from the vehicle speed sensor 2 to the fuel consumption calculation unit 104. The vehicle speed signal V (n) also includes noise having a certain level of amplitude, although not as large as the fuel injection amount signal X (n). For this reason, due to this noise, the fuel consumption information signal P (n) calculated by the fuel consumption calculation unit 104 may vary, and the fuel consumption information may not be stable.

Therefore, in this embodiment, the fuel efficiency information signal P (n) output from the upper limit value limiter 105 is subjected to final filter processing in the fuel efficiency information LPF 106, and the filtered fuel efficiency information signal Q (n) is filtered. The information is input to the display means 3 and displayed to the driver.
The fuel efficiency information LPF 106 is a low-pass filter having the same format as the fuel injection amount LPF 103, and filter coefficients a ₁ and b ₁ (where a ₁ > 0, b ₁ > 0, a ₁ + b ₁ = 1) are set in advance. Has been. However, since the noise amplitude included in the fuel efficiency information signal P (n) is not so large, the filter coefficients a ₁ and b ₁ are sufficient to suppress the noise included in the fuel efficiency information signal P (n). In particular, it is set to a value that does not impair the responsiveness. Note that the fuel efficiency information LPF 106 may be omitted when there is no significant variation in the fuel efficiency information signal P (n).

Next, with reference to FIG. 2, signal stabilization processing in the moving average calculation unit 102 and the fuel injection amount LPF 103 will be described. Here, the latest calculation cycle is set as the calculation cycle n. For example, the fuel injection amount signal in the calculation cycle n is X (n), and the fuel injection amount signal in the previous calculation cycle (n−1) is X (n−. It will be described as 1).
As shown in FIG. 2, the moving average calculation unit 102 has (r−1) delay circuits 120.1 to 120. r-1 and (r-1) adder circuits 121.1-121. r-1 and an amplifier 122 are provided.

  Each delay circuit 120.1-120. Each of r-1 is connected in series, and each of the input signals is configured to be output after being delayed by one calculation cycle. Thereby, each delay circuit 120.1-120. From r−1, fuel injection amount signals from the calculation cycle (n−1) one calculation cycle before to the calculation cycle (n−r + 1) before the calculation cycle (n−1) are output. Yes. And each delay circuit 120.1-120. The fuel injection amount signals output from r-1 are respectively added to the adder circuits 121.1 to 121.12. r-1 is input. Also, each adder circuit 121.1 to 121. r-1 is configured to add and output a plurality of input signals.

  As a result, the addition circuit 121.1 adds the fuel injection amount signal X (n) and the fuel injection amount signal X (n-1) one calculation cycle before, and the addition circuit 121.2 adds to this. Further, the fuel injection amount signal X (n-2) two calculation cycles before is added. Thus, the adder circuits 121.1 to 121. In r-1, the previous fuel injection amount signal is accumulated one calculation cycle at a time, and the addition circuit 121. In r-1, the fuel injection amount signals X (n), X (n-1), and X (n-2) input to the moving average calculation unit 102 in r consecutive calculation cycles including the calculation cycle n. ,... X (n−r + 1) are all integrated and sent to the amplifier 122.

The amplifier 122 is set with a gain that is a value obtained by dividing the input value by the number of fuel injection amount signals added (ie, r), and is supplied to the fuel injection amount LPF 103 as a signal after moving average L (n). It is designed to output.
Thus, in the moving average calculation unit 102, for each calculation cycle, the fuel injection amount signal for the continuous r-1 calculation cycles input up to the previous time and the fuel injection amount signal at the current calculation cycle n. An average value of the total r fuel injection amount signals is calculated as a signal after moving average, and is output to the fuel injection amount LPF 103.

That is, in the calculation cycle n, the moving average calculation unit 102
L (n) = [X (n) + X (n−1) +... + X (n−r + 1)] / r
Is output as a signal L (n) after moving average, and in the next calculation cycle (n + 1), the moving average calculation unit 102
L (n + 1) = [X (n + 1) + X (n) +... + X (n−r + 2)] / r
Is output as a signal L (n + 1) after moving average.

In this embodiment, the value of r described above is set to 50, and the moving average calculation unit 102 is set to calculate the average value of the fuel injection amount for the most recent 50 calculation cycles every calculation cycle. is doing.
In this way, by performing a moving average process on a signal having a variation (that is, noise) for each calculation cycle, short fluctuations of about a small number of calculation cycles are leveled, and the noise amplitude is reduced. Therefore, the noise included in the post-moving average signal L (n) has a smaller amplitude than the noise included in the fuel injection amount signal X (n).

  Although the response delay for the moving average process varies depending on the predetermined number of cycles r set in advance, the value of the predetermined number of cycles r is set so that the response delay of the signal after moving average becomes small. In general, the response delay of the moving average process is much smaller than the response delay of a recursive primary low-pass filter such as the fuel injection amount LPF 103 described later, and the signal after the moving average with respect to the fuel injection amount signal Response delay is small.

Next, the fuel injection amount LPF 103 will be described. The fuel injection amount LPF 103 includes a first amplifier 131, a second amplifier 132, a delay element 133, and an adder circuit 134.
Gains a and b corresponding to predetermined filter coefficients a and b (where a + b = 1, a> 0, b> 0) are set in the first amplifier 131 and the second amplifier 132, respectively. The amplifier 131 and the second amplifier 132 multiply the input signals by gains a and b, respectively, and output the result.
The delay circuit 133 includes the delay circuits 120.1 to 120. Similarly to r-1, the input signal is output after being delayed by one calculation cycle, and the adder circuit 134 includes the above adder circuits 121.1 to 121. Similarly to r-1, a plurality of input signals (here, two signals) are added and output.

  Accordingly, the post-moving average signal L (n) input to the fuel injection amount LPF 103 in the calculation cycle n is input to the first amplifier 131 and sent to the adder circuit 134 as a signal aL (n) multiplied by the gain a. The Further, the second amplifier 132 receives the filtered signal F (n−1) one operation cycle before from the delay circuit 133 and sends it to the adder circuit 134 as a signal bF (n−1) multiplied by the gain b. Is done.

The adding circuit 134 adds the signals aL (n) and bF (n−1) input from the first amplifier 131 and the second amplifier 132, respectively.
Filtered signal F (n) = aF (n−1) + bL (n)
Is output.

The filter coefficients a and b are values set in advance so that a minute change (noise) included in the signal L (n) after moving average can be sufficiently suppressed. In this case, as the filter coefficient a is increased and the filter is made heavier, noise with a large amplitude can be sufficiently suppressed. On the other hand, since the response delay with respect to the change of the input signal increases, the values of the filter coefficients a and b are increased. Is preferably set to such a value that the noise can be reliably suppressed and the response delay to the change in the signal L (n) after the moving average does not increase. Since the amplitude of the noise included in the injection amount signal X (n) is reduced, and the noise L having a large amplitude is hardly included in the moving average signal L (n), the values of the filter coefficients a and b are The value can be set so that the response delay becomes small.
As described above, in the present invention, the moving average calculation unit 102 performs the filtering process on the fuel injection amount LPF 103 after performing the moving average processing, and thus the response is included in the fuel injection amount signal X (n). Noise can be reliably suppressed.

  Since the vehicle fuel consumption calculation device according to an embodiment of the present invention is configured as described above, in particular, the moving average calculation unit 102 reduces the amplitude of noise included in the fuel injection amount signal X (n). . As a result, when the post-moving average signal L (n) with reduced noise amplitude is filtered by the fuel injection amount LPF 103, the value of the filter coefficient a set in the first amplifier 131 of the fuel injection amount LPF 103 is set. Even if the filter is lightened by setting it large (decreasing the value of b), the noise contained in the signal L (n) after moving average can be sufficiently suppressed. Further, when the value of the filter coefficient a is set to be large, the filtered signal F (n) is greatly influenced by the latest moving average signal L (n). Responsiveness to changes in L (n) can be improved. Thereby, as shown in FIG. 3, the response delay ΔT of the filtered signal F (n) with respect to the fuel injection amount signal X (n) can be reduced.

  As described above, in the present embodiment, after first performing the moving average process on the fuel injection amount signal X (n), the filter process is performed with a relatively light filter coefficient, thereby suppressing noise and good responsiveness. Can be made compatible. However, the signal stabilization signal F ′ (n) obtained by first performing the filtering process on the fuel injection amount signal X (n) and then performing the moving average process has good responsiveness as shown in FIG. The inventor of the present application confirmed that the above cannot be secured.

For this reason, as a characteristic when performing signal stabilization processing on the fuel injection amount signal X (n), the moving average processing has an effect of reducing noise amplitude with good response to noise with large amplitude. Although it is obtained, when the moving average process is performed on noise having a small amplitude, the noise amplitude suppressing effect is reduced.
For this reason, when the signal stabilization process is performed on the fuel injection amount signal X (n), the low-pass filter process is first performed, and then the moving average process is performed to sufficiently suppress noise. Therefore, it is necessary to increase the filter coefficient b of the fuel injection amount LPF 103 described above (to increase the filter weight) or to increase the value of the predetermined period number r in the moving average calculation unit 102. As a result, as shown in FIG. As a result, a large response delay ΔT occurs.

[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
In the above-described embodiment, the fuel efficiency calculation device of the present invention is applied to a vehicle equipped with a diesel engine. However, the internal combustion engine to be mounted is not limited to a diesel engine, but can be applied to a gasoline engine as well. In the embodiment, the calculation result of the fuel consumption calculation device of the present invention is displayed so that the driver is enlightened with driving with good fuel consumption, but the calculation result of the fuel consumption calculation device is used for such fuel consumption. The present invention is not limited to the information display device, and can be applied to anything.

  In the above-described embodiment, the calculated fuel consumption information signal P (n) is filtered to suppress noise. However, in the present invention, the fuel injection amount information is subjected to moving average processing to reduce the noise. Filtering with the low-pass filter sufficiently suppresses the noise included in the fuel injection amount information, so that the noise included in the fuel efficiency information signal P (n) is also suppressed.

  Therefore, when the noise included in the fuel consumption information signal P (n) is sufficiently small, the fuel consumption information LPF 106 can be omitted. On the other hand, when the vehicle speed information includes a large noise, the noise included in the fuel efficiency information signal P (n) may be increased. In such a case, similarly to the fuel injection amount signal X (n), the fuel efficiency information signal P (n) may be first subjected to a moving average process and then filtered using the fuel efficiency information LPF 106. In this way, as with the signal stabilization processing of the fuel injection amount signal X (n) in the embodiment, the fuel consumption information signal P (n) can be reliably suppressed with noise and ensured good responsiveness. Both can be achieved.

In the above-described embodiment, the time of the calculation cycle is 20 milliseconds, which is most suitable, but the time of one calculation cycle is not limited to this.
However, if the calculation cycle is set longer than about 40 milliseconds, the frequency of calculation and control is reduced, so the load on the CPU and the like is reduced. However, the fuel injection amount signal X (n), the vehicle speed signal V (n), etc. The accuracy (data density) is lowered, and the accuracy of the calculated fuel consumption information is impaired.

In addition, if the calculation cycle is set shorter than about 10 milliseconds, the accuracy of the calculated fuel consumption information is improved, but the calculation and control frequency per hour is excessive, and the load on the CPU is large. Too much.
For this reason, the length of the calculation cycle is set in the range of about 10 to 40 milliseconds so that the response delay to the fuel injection amount signal is not increased and the control accuracy is not deteriorated while suppressing the load on the calculation process. It is preferable to do this.

In the embodiment, the value of the predetermined number of cycles r set in the moving average calculation unit 102 is not limited to 50.
However, if the value of the predetermined period number r is too large, the response delay of the signal after moving average with respect to the fuel injection amount signal becomes large.
Further, if the value of the predetermined cycle number r is too small, the amplitude of noise included in the fuel injection amount signal cannot be sufficiently reduced. For this reason, it is preferable to set the value of the predetermined period number r in the range of 25-100.

It is a block diagram which shows schematic structure of the fuel consumption calculating apparatus based on one Embodiment of this invention. It is a circuit diagram showing typically an arithmetic circuit concerning stabilization processing of fuel injection amount information concerning one embodiment of the present invention. It is a graph which shows an example of a time-dependent change of the fuel-injection-quantity signal and filtered signal which filtered this based on one Embodiment of this invention. It is a graph which shows an example of a time-dependent change of the fuel injection amount signal and the signal after signal stabilization when the processing order of the moving average process and the low-pass filter process is reversed according to an embodiment of the present invention. It is a graph which shows an example of the time-dependent change of the input signal before a filter, and the signal after a filter regarding the fuel injection amount signal used for a general fuel consumption calculating apparatus.

Explanation of symbols

1 ECU
2 Vehicle speed sensor 3 Display device 101 Fuel injection amount setting unit 102 Moving average calculation unit (moving average means)
103 Fuel injection amount LPF (filter means)
104 Fuel consumption calculation unit 105 Upper limit value limiter 106 Fuel consumption information LPF
120.1-120. r-1, 133 delay circuit 121.1-121. r-1,134 adder circuit 122 amplifier 131 first amplifier 132 second amplifier

Claims (5)

In a fuel consumption calculation device that calculates fuel consumption for each predetermined calculation cycle based on fuel injection amount information to an internal combustion engine mounted on a vehicle,
Moving average means for moving average processing the fuel injection amount information;
Filter means for low pass filtering the output of the moving average means;
A vehicle fuel consumption calculation device characterized by comprising: The moving average means is calculated every calculation cycle,
The fuel consumption calculation device for a vehicle according to claim 1, wherein: The filter means performs low-pass filter processing on the output of the moving average means for each calculation cycle,
The output value F (n) output from the filter means in the calculation cycle n, the input value L (n) input to the filter means in the calculation cycle n, and the calculation cycle (n−1) one calculation cycle before The output value F (n−1) output from the filter means in FIG.
F (n) = aL (n) + bF (n-1)
However, a + b = 1, a> 0, b> 0
The vehicle fuel consumption calculation device according to claim 1, wherein the relationship is satisfied. 4. The vehicle fuel consumption calculation apparatus according to claim 2, wherein the cycle of the calculation cycle is 10 to 40 milliseconds, and the predetermined cycle number r is 25 to 100. 5. The vehicle internal combustion engine according to any one of claims 1 to 4, wherein the internal combustion engine is a diesel engine.

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