JP7184238B2 - Remaining amount of fuel calculation device for vehicle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a remaining fuel amount calculating device for a vehicle.

The fuel remaining amount display of an automobile has an important meaning for the driver to accurately grasp the remaining fuel amount. In the fuel remaining amount display of the automobile, the fuel consumption is calculated from the sender method (1) that detects the liquid level by the float type fuel sender installed in the fuel tank and the valve opening time of the fuel injection device (injector), and refueling An injector method (2) is known, which calculates the remaining amount of fuel by subtracting the consumed fuel from the fuel at the time.

In the sender method (1), the remaining amount of fuel A is calculated as follows based on the time average value A (for example, the average value for about 3 seconds) calculated from the sender input value. That is, when remaining fuel amount A> time average value A, the current remaining fuel amount A is calculated by subtracting a predetermined amount Ka from the previous remaining fuel amount A.
Remaining fuel A(n) = Remaining fuel A(n-1) - Ka (1-1)
When remaining fuel A< time average value A, a predetermined amount Ka is added to remaining fuel A to calculate the remaining fuel. (Ka may be a value proportional to the difference between the remaining amount of fuel A and the time average value A)
Remaining amount of fuel A(n)=Remaining amount of fuel A(n-1)+Ka (1-2)
Since the remaining fuel A calculated by this sender method (1) uses the fuel sender input, if the vehicle is about to tilt, the actual remaining fuel A will be affected by the fluctuation of the liquid level. There is a problem that a large deviation occurs.

On the other hand, in the injector method (2), the remaining amount of fuel is calculated as follows.
Remaining amount of fuel B(n) = Remaining amount of fuel B(n-1) - Integrated fuel consumption value (2)
However, since the remaining fuel amount B calculated by this injector method (2) uses the fuel consumption, it is not affected by slopes like the sender method (1), but the initial value of the remaining fuel amount Accumulated deviations and integration errors may also cause deviations from the actual remaining amount.

Therefore, the following modification method (3), in which the injector method (2) is further modified to gradually approach the remaining amount of fuel A based on the sender value, is also conceivable.
Remaining fuel B(n) = Remaining fuel B(n-1) - Integrated fuel consumption value + K (K: correction value) (3)
In the correction method (3), the correction value K is set according to the difference between the remaining amount of fuel B and the remaining amount of fuel A calculated from the fuel sender. When the remaining amount of fuel B is larger than the remaining amount of fuel A, subtraction is performed as K<0. Further, when the remaining amount of fuel B is smaller than the remaining amount of fuel A, K>0 is added. However, this modification method (3) is also affected by slopes in the same way as the sender method (1).

In Patent Document 1, similarly to the injector method (2), a fuel remaining amount calculation device that calculates the fuel consumption from the valve opening time of the injector, subtracts the fuel consumption from the fuel amount at the time of refueling, and displays the remaining fuel amount. is disclosed. In addition, in consideration of the fact that the remaining amount becomes inaccurate due to manufacturing errors in the fuel injection device, this patent document 1 discloses that when the liquid level in the fuel tank reaches a preset level, the remaining amount is calculated. I am trying to correct the display.

JP-A-58-122433

However, in the technique of Patent Document 1, correction is performed only at a preset liquid level height, and in other states, there is a possibility that the error from the actual remaining amount may become large. In addition, as in the injector method (2) and the correction method (3), in calculating the remaining amount of fuel using the fuel consumption, two filters with different responsiveness are compared to determine the stability of the liquid level and determine the stability. Although it is conceivable to make corrections only when the oil level is constantly swaying on mountain roads, etc., there is no opportunity to make corrections, and there is a risk that accumulated fuel consumption errors will accumulate. In order to avoid this, if feedback correction is performed using the sender input value, the frequency of unnecessary correction will increase.

In view of the above, the present invention is a vehicle capable of calculating (displaying) an accurate remaining fuel amount by correcting the remaining fuel amount calculated from the consumed fuel at a constant rate to eliminate the accumulation of accumulated errors in the fuel consumption amount. The object of the present invention is to provide a remaining amount of fuel calculating device.

In order to achieve the above object, in a preferred embodiment of the present invention, the fuel consumption obtained from the injector valve opening time is subtracted from the fuel amount at the time of refueling, and the calculated remaining fuel amount (B) and the fuel tank A control unit that calculates the final remaining fuel amount using the remaining fuel amount (A) calculated based on the input from the fuel sender that detects the liquid level height of the fuel When the remaining amount (B) is corrected at a constant rate, the correction coefficient (Kτ) of the constant rate correction formula is switched according to the following factors a), b), and c) to reduce the accumulated error of the estimated remaining fuel amount. a) magnitude relationship between the remaining fuel amount (B) obtained from the injector valve opening time and the predetermined remaining fuel value (C0), b) the remaining fuel amount (B) obtained from the injector valve opening time and the input from the fuel sender c) the direction of deviation between the remaining fuel amount (B) obtained from the injector valve opening time and the time average value (A') of the fuel sender value.

Here, the constant rate correction formula is defined as follows, for example.
Remaining amount of fuel B(n) = Remaining amount of fuel B(n-1) - Integrated fuel consumption value x Kτ (5)
Also, the predetermined remaining fuel value (C0) is determined depending on whether there is a margin in the remaining fuel amount. For example, assume that the predetermined remaining fuel value is 10 liters.

When there is a margin in the remaining amount of fuel, the switching of the correction coefficient Kτ is performed using a relatively large amount of deviation (for example, 2 liters (L)) as a threshold value. When the remaining amount of fuel (B) is less than the predetermined remaining fuel value, there is no margin in the remaining amount of fuel. Therefore, in order to prevent gas shortage, etc., the correction coefficient Kτ is switched by a relatively small amount of deviation (for example, 1 liter (L) ) as the threshold. In this case, depending on the amount of deviation between the remaining amount of fuel (B) and the remaining amount of fuel (A), furthermore, the direction of deviation (large or small) between the remaining amount of fuel (B) and the time average value (A') of the fuel sender value The correction coefficient Kτ is switched according to the relation).

Therefore, not only when performing quantitative correction (correction is performed by fixed amount regardless of the amount consumed) that is performed when the liquid level is stable, but also when the liquid level is not stable and quantitative correction cannot be performed, constant rate correction ( By performing the correction amount proportional to the consumption amount and sufficiently smaller than the quantitative correction), it is possible to eliminate the accumulation of errors in the display (Hτ) of the remaining amount of fuel (B).

According to the present invention, a) the magnitude relationship between the remaining fuel amount (B) and the predetermined remaining fuel amount (C0), b) the deviation amount between the remaining fuel amount (B) and the remaining fuel amount (A), c) the remaining fuel amount Since the correction coefficient Kτ for correcting the remaining fuel amount (B) at a constant rate is changed according to the direction of divergence (magnitude relationship) between the amount (B) and the time average value (A′) of the sender value, the remaining fuel amount Accumulation of errors in quantity indication can be eliminated.

1 is a control block diagram of a vehicle remaining fuel amount calculating device according to an embodiment of the present invention; FIG. It is similarly a calculation flowchart of a fuel residual quantity. FIG. 3 is a flowchart relating to determination of quantitative correction in FIG. 2; FIG. It is a constant rate correction coefficient Kτ switching table. FIG. 5 is a calculation flowchart showing an example of constant rate correction switching of the remaining amount of fuel corresponding to the switching table of FIG. 4 ; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a vehicle speed sensor 3 for detecting the speed of a vehicle is provided on the input side of a vehicle electronic control unit (ECU) serving as a control unit 2. A float-type fuel sender 4 that detects the remaining amount of fuel from the height of the liquid level in the fuel tank, and a fuel consumption detector 5 that outputs the amount of fuel consumed obtained from the valve opening time of the injector (fuel injection device). It is connected.

In the control unit 2, the remaining amount of fuel (B) calculated by subtracting the fuel consumption obtained from the injector valve opening time from the fuel amount at the time of refueling, and the fuel calculated from the liquid level height of the fuel tank by the fuel sender 4 The remaining fuel amount (A) is used to calculate the final remaining amount of fuel. In the control unit 2, the remaining amount of fuel (A) detected from the liquid surface height of the fuel sender 4 is input to the remaining amount of fuel calculation unit 8 via the time average value 7, and the remaining amount of fuel is obtained from the valve opening time of the injector. The amount of fuel consumed is integrated by the integrating section 9, calculated by the fuel remaining amount calculating section 8, and the result is displayed on the fuel remaining amount display section 6. FIG.

In the control unit 2, the remaining amount of fuel calculation unit 8 performs quantitative correction when the liquid level is stable. Quantitative correction is corrected by fixed quantity regardless of consumption. In addition to this quantitative correction, the controller 2 performs constant rate correction in order to eliminate accumulation of errors when the liquid level is not stable and quantitative correction cannot be performed. Fixed-rate correction is a correction amount proportional to the amount of consumption, and the correction is performed with a value sufficiently smaller than the quantitative correction.

In the control unit 2, when performing the constant rate correction, the correction coefficient Kτ of the constant rate correction formula is switched according to the following factors a), b), and c)), and the estimated remaining fuel amount is reduce the accumulated error of
a) magnitude relationship between remaining fuel amount (B) and predetermined remaining fuel value (C0);
b) the amount of deviation between the remaining amount of fuel (B) and the remaining amount of fuel (A) calculated based on the input from the fuel sender;
c) Direction of divergence between the remaining amount of fuel (B) and the time average value (A') of the fuel sender value.

The calculation method in the remaining fuel amount calculation section 8 of the control section 2 will be described based on the calculation flow charts and correction coefficient selection tables of FIGS. 2 to 5. FIG. FIG. 2 is a flow chart for calculating the remaining amount of fuel, and FIG. 3 is a flow chart for quantitative correction determination in FIG.

In FIG. 2, the remaining amount of fuel calculation unit 8 calculates the remaining amount of fuel at predetermined intervals (for example, every 12 seconds). First, in FIG. 2, quantitative correction determination (S1) is performed, and then constant rate correction is performed (S2). Next, in the quantitative correction determination (S1), it is determined whether the quantitative correction flag is "1" or "0" (S3). If the quantitative correction flag is "1", quantitative correction is performed based on the quantitative correction formula (S4). After the quantitative correction (ii) is completed, the quantitative correction flag is cleared ("0") (S5), and the calculation of the remaining amount of fuel ends.

The constant rate correction formula and quantitative correction formula are as follows.
(i) Fixed rate correction formula:
Remaining amount of fuel B(n) = Remaining amount of fuel B(n-1) - Integrated fuel consumption value x Kτ (5)
Incidentally, in the case of quantitative correction, Kτ=1.0 and the following arithmetic expression is obtained.
(ii) quantitative correction formula:
Remaining fuel B(n) = Remaining fuel B(n-1) - Integrated fuel consumption value x Kτ (= 1.0) + Cτ (quantitative correction value) (6)
Note that the quantitative correction value Cτ is, for example, 0.025 liters (L), and is added every one control cycle (12 seconds).

Quantitative correction determination (S1) is performed, as shown in FIG. 3, every predetermined calculation cycle (for example, calculation cycle of 3 seconds). The quantitative correction determination consists of deviation determination (S6), liquid level determination (S7), and vehicle speed determination (S8). The deviation determination (S6) determines whether there is a deviation between the remaining fuel amount (B) calculated from the fuel consumption amount and the remaining fuel amount (A) calculated based on the input from the fuel sender. Deviation refers only to the case of remaining fuel amount (B)>remaining fuel amount (A). The deviation determination value is, for example, 0.2 liters (L), and when the deviation amount is greater than 0.2 (L), it is determined that there is deviation.

The liquid level is determined by determining whether the liquid level is stable based on the difference between the remaining amount of fuel (A) calculated based on the input from the fuel sender and the time average value (A') of the fuel sender input, for example, the 3-second average value. Determine whether or not When the difference between the two is equal to or less than the stability determination liquid amount (for example, 1.0 liter (L)), it is determined that the liquid surface is stable.

Vehicle speed determination (S8) determines whether or not the vehicle speed is less than a predetermined speed. When the vehicle speed is less than a predetermined speed, for example, less than 20 km/h, it is determined that the vehicle is likely to be affected by inclinations and curves, and quantitative correction is prohibited. When the speed is equal to or higher than a predetermined speed, it is determined that the influence of the inclination or the curve is not likely to occur, and quantitative correction can be executed. If the deviation determination (S6), liquid level determination (S7) and vehicle speed determination (S8) are satisfied, the quantitative correction flag is set to "1" (S9), and the quantitative correction determination is terminated.

In FIG. 2, when the quantitative correction determination (S1) is made and the quantitative correction flag is set to "1", the quantitative correction is performed based on the quantitative correction formula (6) (S4). During quantitative correction determination, constant rate correction is always performed under the following conditions. FIG. 4 is a switching table of the constant rate correction coefficient Kτ. FIG. 5 is a calculation flowchart for switching the constant correction coefficient of the remaining amount of fuel in accordance with the switching table of FIG. 4 .

A calculation flow for constant rate correction will be described with reference to FIGS. 4 and 5. FIG. The ( ) written numbers in the lower margin of the table in FIG. 4 correspond to the ( ) written numbers described in the constant correction coefficient Kτ in FIG. 5 . In the selection of the constant rate correction coefficient (Kτ) in FIG. 5, if the quantitative correction condition is satisfied (S11: Y), the quantitative correction flag is set to "1", the constant rate correction coefficient Kτ is set to 1 (S12), and the process ends (S23). .

If the quantitative correction condition is not satisfied (S11: N), then it is determined whether or not the remaining fuel amount (B) is greater than a predetermined remaining fuel value (C0: 10 liters (L), for example) (S13). If the remaining amount of fuel is smaller than the predetermined remaining amount of fuel (C0) (S13: N), the switching thresholds C3 and C4 of the correction coefficients are set smaller in preparation for gas shortage or the like.

When the remaining amount of fuel (B) is greater than the predetermined remaining fuel value (C0) (S13: Y), the degree of divergence between the remaining amount of fuel (B) and the remaining amount of fuel (A), and the remaining amount of fuel (B) The deviation direction (magnitude relationship) between the sender value and the time average value (A') is determined (S14). If the degree of divergence between the remaining amount of fuel (B) and the remaining amount of fuel (A) is greater than a first threshold value C1 (for example, C1=2 liters (L)), the remaining amount of fuel (B) and the time average value When the deviation direction (magnitude relationship) from (A') is positive (the remaining amount of fuel (B) is greater than the time average value (A')) (S14: Y), the correction coefficient Kτ is set to Kτ=K1 (for example , K1=1.5), the remaining amount of fuel (B) is calculated by the constant rate correction formula (5) below, and the remaining amount of fuel is displayed (Hτ).

Remaining amount of fuel B(n) = Remaining amount of fuel B(n-1) - Integrated fuel consumption value x Kτ (5)
As a result, since K1>1, the accumulated fuel consumption value to be subtracted increases, and the calculated remaining fuel amount (B) approaches the time average value (A') more quickly, resulting in remaining fuel display (Hτ).

If the degree of divergence between the remaining amount of fuel (B) and the remaining amount of fuel (A) is equal to or less than the first threshold value C1 (S14: N), then it is determined whether the degree of divergence is greater than 0 ( S16). In other words, it is determined whether or not the degree of divergence is between C1 and 0. The degree of divergence is greater than 0, and the divergence direction (magnitude relationship) between the remaining fuel amount (B) and the time average value (A') is positive (the remaining fuel amount (B) is greater than the time average value (A'). ) (S16: Y), switch to the correction coefficient Kτ=K2 (for example, K2=1.1), calculate the remaining amount of fuel (B) based on the above-mentioned (i) constant rate correction formula (5), Remaining fuel display (Hτ) is performed. In this case, by setting K1>K2, the subtraction amount of the integrated fuel consumption value is reduced, and the remaining fuel display (Hτ) that the remaining fuel amount (B) gradually approaches the time average value (A'). do.

If the degree of divergence between the remaining fuel amount (B) and the remaining fuel amount (A) is 0 (S18: Y), the remaining fuel amount (B) and the remaining fuel amount (A) match, so fuel consumption No need to correct the integrated value. Therefore, the correction coefficient Kτ is switched to 1 (S19).

If the degree of divergence between the remaining amount of fuel (B) and the remaining amount of fuel (A) is greater than a second threshold value C2 (for example, C2 = -2 liters (L)), for example, 0 to -2 liters (L ), when the deviation direction is negative (remaining amount of fuel (B) is smaller than the time average value (A')) (S20: Y), the constant rate correction formula ( 5) Switch to the correction coefficient Kτ=K3 (for example, K3=0.9), reduce the subtraction amount, and display the remaining fuel (Hτ) in which the remaining fuel amount (B) gradually approaches the time average value (A') and

If the degree of divergence between the remaining fuel amount (B) and the remaining fuel amount (A) is smaller than the second threshold value C2 (for example, smaller than -2 liters) and the direction of the deviation is negative (remaining fuel amount (B) is smaller than the time average value (A') (S20: N), switch to the correction coefficient Kτ = K4 (for example, K4 = 0.5) in the constant rate correction formula (5) (S22), and the integrated fuel consumption value By making the correction coefficient Kτ smaller than K3, the amount of subtraction is made smaller, and the remaining fuel amount (B) approaches the time average value (A') more quickly.

When the remaining fuel amount (B) is equal to or less than the predetermined remaining fuel value (C0) (S13: N), the degree of divergence between the remaining fuel amount (B) and the remaining fuel amount (A) reaches a third threshold value C3 (for example , C3=1 liter (L)) (S25). When the degree of deviation is greater than the third threshold value C3 and the direction of deviation is positive (greater than the remaining fuel amount (B) and the time average value (A')) (S25: Y), the correction coefficient Kτ=K5 (For example, K5 = 1.5) (S26), the amount of subtraction from the integrated fuel consumption value is increased, and the remaining fuel amount (B) approaches the time average value (A') more quickly. (Hτ).

If the degree of divergence between the remaining amount of fuel (B) and the remaining amount of fuel (A) is equal to or less than the third threshold value C3 (S25: N), then it is determined whether the degree of divergence is greater than 0. (S27). If the degree of divergence is greater than 0 and the direction of divergence is positive (remaining amount of fuel (B) is greater than time average value (A′)) (S27: Y), correction coefficient Kτ=K6 (for example, K6=1 1), the accumulated fuel consumption value is increased and subtracted, and the residual fuel display (Hτ) is displayed so that the remaining fuel amount (B) gradually approaches the time average value (A') (S28).

If the degree of divergence between the remaining amount of fuel (B) and the remaining amount of fuel (A) is "0" (S29: Y), the remaining amount of fuel (B) and the remaining amount of fuel (A) match. There is no need to correct the consumption integrated value. Therefore, the correction coefficient Kτ is switched to 1 (S30).

If the degree of divergence between the remaining amount of fuel (B) and the remaining amount of fuel (A) is greater than a fourth threshold value C4 (for example, C4 = -1 liter (L)) (for example, 0 to -1 liter ( L)) and the divergence direction is negative (remaining amount of fuel (B) is smaller than time average value (A')) (S31: Y), correction coefficient Kτ=K7 (for example, K7=0.9) to reduce the subtraction amount of the fuel cost integrated value.

The degree of divergence between the remaining fuel amount (B) and the remaining fuel amount (A) is smaller than the fourth threshold value C4 (for example, C4=-1 liter (L)), and the deviation direction is negative (remaining fuel amount ( B) is smaller than the time average value (A') (S31: N), switch to the correction coefficient Kτ=K8 (for example, K8=0.5) (S33), and change the remaining fuel amount (B) to the time The selection of the constant rate correction coefficient is finished as the residual fuel display (Hτ) that more quickly approaches the average value (A') (S23).

Here, the correction coefficient Kτ exemplified above is described with its specific numerical value shown in parentheses. K1(1.5)>K2(1.1)>1>K3(0.9)>K4(0.5)>0, and K5(1.5)>K6(1.1)>1>K7 (0.9)>K8(0.5). Further, the threshold values are C1 (2 liters)>C3 (1 liter)>0>C4 (-1 liter)>C2 (-2 liters). Note that specific numerical values of the correction coefficient Kτ and the threshold value C are not limited to those illustrated above.

By selecting and setting the constant rate correction coefficient in this manner, when there is little remaining fuel, the constant rate correction increases the correction coefficient (correction rate) as the amount of deviation from the sender value increases, thereby enhancing followability to the sender value. Further, when the amount of deviation from the sender value is small when the amount of fuel is sufficient, unnecessary correction is suppressed by reducing the correction coefficient (correction rate). In addition, by switching the correction coefficient whether the divergence direction is greater than the sender value (there is a concern of running out of gas) or when it is smaller than the sender value, followability to the sender value is enhanced.

As described in the above embodiments, the present invention provides: a) the magnitude relationship between the remaining fuel amount (B) and the predetermined remaining fuel value (C0); and b) the relationship between the remaining fuel amount (B) and the remaining fuel amount (A). Deviation amount, c) A correction coefficient Kτ for constant correction of the remaining fuel amount (B) according to the deviation direction (magnitude relationship) between the remaining fuel amount (B) and the time average value (A') of the sender value. Since it is changed, it is possible to eliminate the accumulation of errors in the display of the remaining amount of fuel.

It should be noted that the present invention is not limited to the above-described embodiments, and of course many modifications and changes can be made within the scope of the present invention. For example, in the above embodiment, the quantitative correction and the constant rate correction are combined, but the present invention can also be applied to the case where only the constant rate correction is performed alone. Further, the quantitative correction conditions are not limited to the three conditions of divergence determination, liquid level stability, and vehicle speed determination as in the above embodiment. Of course, it is also good.

1 fuel remaining amount calculation device 2 control unit 3 vehicle speed sensor 4 fuel sender 5 fuel consumption amount detection unit 6 fuel remaining amount display unit 7 hourly average value
8 Remaining amount of fuel calculator 9 Accumulator

Claims (1)

Calculated based on the remaining amount of fuel (B) calculated by subtracting the fuel consumption obtained from the injector valve opening time from the fuel amount at the time of refueling, and the input from the fuel sender that detects the liquid level in the fuel tank. In a vehicle fuel remaining amount calculation device having a control unit that calculates the final remaining fuel amount using the remaining fuel amount (A),
When correcting the remaining fuel amount (B) at a constant rate, the control unit switches the correction coefficient (Kτ) according to the following factors a), b), and c) to reduce the accumulated error of the estimated remaining fuel amount. A remaining amount of fuel calculating device characterized by:
a) magnitude relationship between the remaining amount of fuel (B) obtained from the injector valve opening time and a predetermined remaining fuel value (C0);
b) the amount of deviation between the remaining amount of fuel (B) obtained from the injector valve opening time and the remaining amount of fuel (A) calculated based on the input from the fuel sender;
c) Direction of divergence between the remaining amount of fuel (B) obtained from the injector valve opening time and the time average value (A') of the fuel sender value.

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