JPS61193999A - Measuring system of quantity of combusion of missile - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a method for measuring fuel in a fuel tank attached to an aircraft with attitude fluctuations, particularly based on fuel level and liquid level slope correction. The present invention relates to a fuel measurement system for an aircraft that calculates remaining fuel weight and achieves high accuracy of calculation output.

<Prior Art> The conventional technology will be explained by taking as an example a fuel measurement system for an aircraft that measures fuel type FFI 175M attached to an aircraft, which is a representative aircraft. Incidentally, when the fuel level sensor for measuring the fuel is used in an aircraft, a capacitance type tank unit is generally widely used, so it is expressed as "T/U" (abbreviation for tank unit).

Note that this system uses a system with linear changes.

□Figure 3 shows the components of a conventional aircraft fuel measurement system.

For this purpose, the fuel level in the fuel tank is measured by T/U, and the angle of inclination of the fuel level is measured using an accelerometer, taking advantage of the fact that the fuel level is perpendicular to acceleration. It is necessary to calculate the remaining fuel weight based on the level and the liquid level inclination angle.

The conventional technique will be explained below with reference to FIG.

In Figure 3, T/LJ1 ((T/Ll in the figure)
a,...(T/U)c) measures the fuel level of fuel Q in the fuel tank T (Z+,...Z3 in the figure), and measures the fuel level in the X direction, Y direction, and two directions of the aircraft. The acceleration is measured by the accelerometer 3, the fuel calculation unit 2 calculates the liquid level inclination angle based on the acceleration, and then the fuel is calculated based on the liquid level inclination angle and the fuel level. ! It calculates and outputs the remaining amount W.

The fuel calculation unit 2 calculates a liquid level inclination angle with a fuel input interface (hereinafter referred to as rT/FJ) 21 to which T/Ul is connected, and based on this liquid level inclination angle and fuel level. A calculation function 22 that calculates the remaining fuel weight W and a storage element (ROM
23, a random access memory (RAM) 24 for accessing necessary information as needed, an output 1/F 25 for outputting this fuel calculation result to the outside, and an acceleration human power 1/F 26 for inputting acceleration signals.

<Problems to be Solved by the Invention> By the way, with such a fuel measurement system, it is not sufficient to follow up the installation of an aircraft wing by calculating a tilt correction value of 1q from the signal of the accelerometer 3 in response to changes in angle, etc. I can't. In the case of large aircraft, the fuel tanks are located inside the wings, and depending on conditions on the ground and in the air, the dihedral angle (mounting angle with respect to the aircraft) changes and acceleration is applied, resulting in accurate liquid level inclination (fuel relative to the fuel tank). It is difficult to detect the slope of the liquid level, which results in an error in the remaining fuel output. The accelerometer 3 for measuring the liquid level inclination angle is typically installed iQI in the fuselage of the aircraft. However, fuel tank T
It is generally considered that the angle at which the yellow is installed will fluctuate, so if you take this into consideration, unless the accelerometer 3 is installed inside the wing, it will not be possible to measure the accurate inclination angle, resulting in an error. Possible cases where the attachment angle of the wing changes include that the dihedral angle changes greatly between on the ground and in the air, and that the deflection of the wing increases as the fuel Q increases during fuel supply on the ground. When correcting the liquid level inclination using the acceleration signal from accelerometer 3, it is fine if the whole does not change, but
As described above, when the blade is in a deflected state, a deflection error occurs. Therefore, it is not possible to accurately determine the value of the fuel weight class MW.

By the way, it is naturally possible to obtain liquid level slope correction along with °fuel level with at least three T/Us, but with three T/Us, the dynamic range for the slope angle is narrow, and if you try to widen the dynamic range, you will inevitably have to adjust the T/U. A large number of U's are required. This increases the overall weight, which is unfavorable in terms of maintenance, fuel consumption, etc. There is a problem.

The present invention has been made in view of the problems of the conventional technology, and is a method for calculating the remaining amount of fuel weight in the fuel tank of a flying vehicle that undergoes attitude fluctuations. Conventionally, in fuel measurement systems, regardless of whether the aircraft is on the ground or in the air, the fuel level is measured by T/U, and the liquid level slope calculation uses the value measured by an accelerometer.
Alternatively, everything is measured and calculated by T/Ll, but in the present invention, the fuel level is measured by T/U, and the liquid level slope calculation is performed by three T/Us on the ground. By using a 311m meter in the air, the accuracy of the overall liquid level slope calculation is improved, and each liquid level slope calculation n value and T /
It is an object of the present invention to provide a fuel measurement system for an aircraft that accurately and highly accurately measures the remaining fuel weight based on the fuel level determined by U and is not affected by the deformation of the wing of the aircraft.

Means for Solving the Problems〉 To achieve the above-mentioned object, the fuel measuring system for an aircraft of the present invention includes a fuel level sensor that measures the level and slope of the fuel of the aircraft, and a fuel level sensor that measures the state of the fuel of the aircraft. l1lII'I
It consists of a takeoff and landing confirmation switch that turns 0N10FF along with the ground, and a fuel control unit that is connected to an acceleration needle that measures the acceleration of the whole flight and calculates the remaining amount of fuel ff1ffi.

Therefore, the arithmetic device is.

■: Recognizes that the aircraft is in the air by the signal of the m landing confirmation switch, calculates the fuel level slope correction calculation value based on the signal of the accelerometer, and is on the ground, calculates the fuel level slope calculation value based on the liquid level that is the signal of the fuel level sensor, and calculates the liquid level slope correction calculation value and liquid level slope calculation value and the fuel It has a function to calculate the remaining fuel weight based on the fuel level measured by the level sensor.

The structure is as follows.

<Example> Hereinafter, an example of the present invention will be described in detail based on the drawings. It should be noted that overlapping parts in the drawings shown below and FIG.

FIG. 1 is a block diagram of a fuel measuring system for an aircraft according to the present invention.

In FIG. 1, 4 is an fIB landing confirmation switch (hereinafter abbreviated as "GAS SWJ") which is provided on the landing leg of the aircraft and turns 0N10FF when the aircraft takes off and lands, and 20 is T/U1 and GAS SW4. and accelerometer 3 are connected, and the remaining fuel weight is ff1W2Witlf.
fi13 operation 1 (26 GAs SW1/F). This fuel calculation unit 20 recognizes when the aircraft is in the air based on the signal from the GAs SW 4 and uses the accelerometer 3.
The liquid level slope correction calculation value of fuel Q is calculated from the signal of GA.
S Recognizes when the aircraft is on the ground by the signal of SW4, calculates the liquid level slope calculation value of fuel Q from the T/Lll signal, and calculates the liquid level slope correction calculation value and the liquid level slope calculation value and further T/Lll. The fuel weight series mW is calculated based on the value of the fuel level of the fuel Q measured at U1.

Below, in the fuel measurement system for an aircraft configured as described above, the case where the liquid level slope correction calculation value is calculated with the accelerometer 3 and the case where the liquid level slope calculation value is calculated with the T/U 1 will be explained in detail below. explain.

The fuel calculation unit 20 inputs the contact information of the GAS SW 4 and determines whether the aircraft is on the ground or in the air.

(if the aircraft is on the ground) At this time, (7) (T/U) a, (T/U) b, respectively.

Let the liquid level of (T/U)c be Zl, Z2, and Zs. Also, these χ coordinates and V coordinates are respectively (χ1゜M+)
, (χ2.!/2>, (χ3+y3>), the liquid level inclination angle θe + P e in the pitch direction and roll direction of the aircraft
is calculated by the fuel calculation unit 20.

Here, a plane passing through the point (0, O, Zo) of the χ and y coordinates and having a pitch angle θe and a roll angle 5'e is 2, -χ
-tanθ6 +y-tan5'e +Zo ・-(3
). On this plane, there is a point (Zl * !' I
*21), (χa + yx *22)l
(χ3*yx*Z3), so Z, amχ1 atanθ0+ '! l+ ・tanv)e +Zo ・”(4)z
2-χ2・tanθe y2-tarB>, +Z, ・(S)z3-χ3・t
anθe+ '/3・tan9'e +Zo'' (6) is satisfied. Therefore, if these equations are solved for θ and P as simultaneous equations, θ@-jan-' ・ ((Z)-Zl ) (y3- yq )-(Zl-22
)(y3 'l+))/((χ3-χ+)(Vs
2/2) - (χ co - χz) (ys -4/1)
) ...(1]ψe■tan' ・[(23-22)(I3-χI )- (Zl Zl ) (χ3-χ2))/((χ3-
χ+ )(Ma'!12)-(χ3-χ2)(y
3-y+))...(2) is obtained. That is, T/L
It is possible to obtain the liquid level slope calculation value using it.

(if the aircraft is on the ground) FIG. 2 is a diagram showing the relationship between acceleration and liquid level.

From accelerometer 3, acceleration in χ, y, and z directions A
Input y and Az to find the liquid level slope correction. When the fuel is balanced against acceleration, the liquid level inclination angle θs*9's in the pitch direction and roll direction of the aircraft is calculated by the fuel calculation unit 20 based on the following equation.

The liquid level Q1 is balanced on a plane perpendicular to the direction of the acceleration α. At this time, the liquid level inclination angle θ is from Fig. 2, θs = j
a n-' (Ax/Az) -(7)
becomes. Similarly for the roll direction, ψs =
tan-' (Ay /Az > --(8)
becomes. Therefore, the fuel calculation unit 20 calculates each acceleration A x
By inputting +Ay and Az, the liquid level inclination angle can be determined from equations (7) and (8). Based on these liquid level slope calculation values and liquid level slope correction calculation values, the current fuel weight remaining amount W of the aircraft is calculated in the fuel calculation unit 20 using the fuel level directly. The approximate calculation formula, which is an example of the calculation formula, is: W-Zt+KC+θ+, 25'+, 3θP...
(9) becomes. However, K+*K2*K3 is a constant determined corresponding to the interval of the fuel level ZJ and the liquid level inclination angle calculation value θψ, and is determined by a broken line approximation formula.

Although the above description has been made for the case where three T/Us are installed in the yl device, the present invention is not necessarily limited to this, and the present invention can be realized by, for example, installing four or more T/Us in iiQ. is possible.

Further, it goes without saying that the fuel measuring system for an aircraft according to the present invention is not limited to being used in the above-mentioned aircraft, but can be widely used as long as it has similar functions and configurations.

<Effects of the Invention> As described above, the present invention has been specifically explained along with the examples.
The fuel level sensor 9 that measures the fuel of the aircraft, the takeoff and landing confirmation switch that corresponds to the ground of the aircraft, and the acceleration meter that measures the acceleration of the aircraft are connected to calculate the remaining fuel weight. According to the fuel measuring system for an aircraft according to the present invention, which includes a fuel calculation unit that performs the following steps: (1) By changing the inclination detection method on the ground and in the air, the advantages of each method can be utilized. Below, we look at the case of a commercial aircraft with fuel tanks inside the wings: a: On the ground, the aircraft body does not take a tilted attitude, but rather the problem is that the plane bends downward. Therefore, the liquid level slope detection method using T/U can detect the slope including this blade deflection, so the blade deflection does not cause an error, and the number of T/Us immersed in fuel is reduced by the blade deflection. Since the number of T/LJs increases, there is no need to worry about the drawback of this method: ``At least three T/Us need to be immersed in fuel, so it is necessary to increase the number of T/LJs.''

b = When in mid-air, the aircraft tilts significantly as it ascends, descends, turns, etc. (Therefore, a liquid level detection method using acceleration with a wide dynamic range of tilt angle is advantageous.

C: In this way, by accurately obtaining the liquid level slope box using an appropriate sensor depending on the aircraft's current state, the fuel level can be calculated based on this liquid level slope value and the fuel level obtained by T/U. Remaining fuel MW can be obtained with high accuracy.

■: Such a configuration (at least 3 T/Us, accelerometers and G
AS SW), so vQ can be placed in any shape of fuel tank.

(2): Since the liquid level slope correction calculation was performed, the measurement accuracy was improved.

■: Since the structure consists of at least three T/Us, it is more resistant to failures than conventional technology, achieving high reliability, and the T/U as a whole
The number of times may be small when compared to the accuracy obtained with the prior art.

There are other effects.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a fuel measurement system for an aircraft according to the present invention, FIG. 2 is a diagram showing the relationship between acceleration and liquid level, and FIG. 3 is a configuration diagram of a conventional fuel measurement system for an aircraft. 1... Fuel level sensor (T/U), 2, 20.
...Fuel calculation unit, 3...Accelerometer, 4...GAS
sW.

Claims (1)

[Claims] The state of the fuel in the fuel tank provided on the aircraft is measured by a fuel level sensor, the acceleration of the aircraft is measured by an accelerometer, and the remaining fuel weight is calculated based on these measured values. In the fuel measurement system, the system is installed on the aircraft and turns ON/OFF as the aircraft takes off and lands.
the fuel level sensor, the takeoff and landing confirmation switch, and the accelerometer are connected to calculate the remaining fuel weight; Recognizing when the flying object is in the air based on the signal, calculating a liquid level slope correction value for the fuel from the signal from the accelerometer, and recognizing when the flying object is on the ground based on the signal from the takeoff and landing confirmation switch. A liquid level slope calculation value of the fuel is calculated from the signal of the fuel level sensor, and a liquid level slope calculation value of the fuel is calculated from the liquid level slope correction calculation value and the liquid level slope calculation value and the fuel level measured by the fuel level sensor. A fuel measurement system for an aircraft, characterized by calculating the remaining weight.