JP3455283B2 - Fluid volume measuring method and fluid volume measuring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid amount measuring method and a fluid amount measuring device, and more particularly to a main tank of a predetermined shape which is mounted on a moving body and accommodates a fluid, and a reference tank having a small volume is provided in communication therewith. , Changing the volume of the space in both tanks,
The present invention relates to a fluid amount measuring method and a fluid amount measuring device for measuring a fluid amount of a fluid in a main tank based on a pressure fluctuation value in both tanks.

[0002]

2. Description of the Related Art Conventionally, as a volume measuring method and apparatus for measuring the volume of liquid, powder, etc. contained in a tank,
Various methods and apparatuses have been proposed as described in JP-A-2-19717. For example, in the embodiment shown in FIG. 10 of the same publication, for the main tank 30 and the correction tank 31, the volume in each tank is changed by the volume changing mechanism 33 to cause pressure fluctuation, and the second amplitude detector Three
The output γ · P ₀ · v ₀ from 9a is fed to the first amplitude detector 39
The volume V ₂ of the hollow portion of the main tank 30 is calculated by dividing by the output γ · P ₀ · v ₀ / V ₂ from b. Further and to calculate the volume V _L of the liquid or the like contained in the main tank 30 by subtracting the volume V ₂ from the total volume of the main tank 30 (volume). Since the measurement principle is described in the publication, description thereof will be omitted. However, the volume of the space in the main tank 30 (that is, the total volume of the main tank if there is no content in the main tank, the content is If present, the volume other than the contents in the main tank is the main tank 30.
Further, it is disclosed that the calculation can be performed according to the detection output of the pressure fluctuation in the correction tank 31.

Further, in Japanese Patent Laid-Open No. 13820/1993, regarding a volume measuring apparatus as described above, when a main tank is used as a fuel tank of a vehicle, for example, a vehicle equipped with the main tank runs on a paved road. There is a problem that the noise contained in the detection signal of the condenser microphone differs depending on whether the frequency is high or low depending on whether the case is traveling on an unpaved road, and it is not always possible to accurately measure the remaining amount of liquid in the tank. Device has been proposed.

That is, a detector for detecting the frequency of the noise component superimposed on the detection signal detected by the pressure fluctuation detector at at least two points is compared with the magnitude of the noise component detected by this detector, and the comparison result is obtained. Based on the above, there is proposed a device provided with a comparator for outputting a switching signal for changing a passing frequency passing through the filter circuit and a predetermined frequency for driving the volume changing means.

[0005]

However, when the measuring object of the volume measuring device described in the above publication is mounted on a moving body, for example, when it is applied to a fuel residual amount measuring device of a fuel tank of a vehicle, A measurement error occurs depending on the moving state of the moving body. For example, there is a difference between the measured values when the vehicle is stopped and when the vehicle is running, and there is a difference between the measured values even when the vehicle is running, depending on the road surface condition, the driving condition, and the like.

Therefore, the present invention changes the volumes of the spaces in the main tank and the reference tank mounted on the moving body, and measures the amount of fluid in the main tank based on the ratio of the pressure fluctuation values in both spaces. In the method and the fluid amount measuring device, the fluid amount is measured while detecting the moving state of the moving body and monitoring the moving body, and the calculation result of the fluid amount is corrected according to the moving state, resulting in the change of the moving state. Reduce measurement error,
The purpose is to ensure stable measurement accuracy. Although the term “correction tank” is used in the above-mentioned publication, in the present application, the reference tank is used in view of the function of giving a pressure fluctuation to be referred to when measuring the volume of the space in the main tank.

[0007]

In order to achieve the above-mentioned object, the present invention is, as an invention according to claim 1, a main tank of a predetermined shape which is mounted on a moving body and accommodates a fluid, and communicates with the main tank. And a actuator for changing the volume of each of the space in the reference tank and the space above the fluid in the main tank to apply pressure fluctuations, and driving the actuator to drive the main tank. And a fluid amount measuring method of detecting each operating state pressure variation value of the reference tank, calculating a ratio of each operating state pressure variation value, and calculating a fluid amount in the main tank according to a calculation result, The moving state of the moving body is detected, a correction value is set according to the detection result, the calculation result of the fluid amount in the main tank is corrected based on the correction value, and the correction value is set. In which it was decided to update in response to a change in the moving state of the moving body.

Further, as shown in the outline of the construction of the fluid amount measuring apparatus according to the second aspect, a main tank MT of a predetermined shape which is mounted on the moving body MB and accommodates the fluid, and the main tank MT are provided in the main tank MT. A reference tank ST in communication with each other, an actuator AT that changes the volume of each of the spaces in the reference tank ST and a space above the fluid in the main tank MT to apply pressure fluctuations, and a drive unit AM that drives the actuator AT. , First pressure fluctuation detecting means C1 for detecting a pressure fluctuation value in a space above the fluid in the main tank MT
A second pressure fluctuation detecting means C2 for detecting a pressure fluctuation value in the space inside the reference tank ST, and an actuator A.
First and second pressure fluctuation detecting means C in the state where T is activated
Main tank MT and reference tank S detected by 1 and C2
Pressure ratio calculating means PR for calculating the ratio of the operating state pressure fluctuation values of T, and fluid amount calculating means LA for calculating the amount of fluid in the main tank MT according to the calculation result of this pressure ratio calculating means PR, The moving state detecting means MV for detecting the moving state of the moving body MB, the correction value setting means MS for setting a correction value according to the detection result of the moving state detecting means MV, and the correction value set by the correction value setting means MS Based on the fluid amount calculation means L
Correcting means MD for correcting the calculation result of A, and updating means RN for updating the correction value in accordance with the change in the moving state of the moving body MB.
It is intended to be equipped with.

[0009]

In the above fluid amount measuring method, the operating state pressure fluctuation value of each of the main tank and the reference tank is detected while the actuator is operating. Then, the ratio of each operating state pressure fluctuation value is calculated, and the fluid amount in the main tank is calculated based on the calculation result. On the other hand, the moving state of the moving body equipped with the main tank is detected, and the correction value is set according to the detection result. The calculation result of the fluid amount in the main tank MT is corrected based on this correction value, and the correction value is updated according to the change in the moving state of the moving body.

Further, in the fluid amount measuring device constructed as shown in FIG. 1, when the actuator AT is driven by the driving means AM, pressure fluctuation is applied to the spaces in the reference tank ST and the main tank MT. It Thus, the operating state pressure fluctuation values of the main tank MT and the reference tank ST are detected by the first and second pressure fluctuation detecting means C1 and C2 while the actuator AT is operating. Then, the pressure ratio calculation means PR calculates the ratio of the respective operating state pressure fluctuation values, and the fluid amount calculation means LA calculates the amount of fluid in the main tank MT according to the calculation result of the pressure ratio calculation means PR. It On the other hand, the moving state detecting means MV detects the moving state of the moving body MB, and the correction value setting means MS sets a correction value in accordance with the detection result of the moving state detecting means MV. And
The correction means MD corrects the calculation result of the fluid amount calculation means LA on the basis of the correction value set by the correction value setting means MS, and the correction value is changed by the updating means RN according to the change in the moving state of the moving body MB. Will be updated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 relates to an embodiment of a fluid amount measuring device of the present invention and is applied to a fuel residual amount measuring device for measuring a fuel residual amount of a fuel tank mounted on a vehicle VH which is a moving body.
The fuel tank has a main tank 1 that defines a closed space,
Even when the space MS formed above when fuel is injected is the minimum, that is, when the liquid level FL is the maximum, the space M is also generated.
An opening 1a is formed at a position communicating with S. A cylindrical reference tank 2 is accommodated in this opening 1a, a flange portion 2f formed at one end thereof is pressed against the opening 1a via a gasket 3a, and further, a flange portion 2f is inserted through a gasket 3b. The cover 4 is pressed. Also,
A case 5 shown by a broken line is joined to the cover 4, and a closed space is defined between the two. The case 5, the cover 4, the flange portion 2f, and the gaskets 3a and 3b are fixed to the main tank 1 by an annular retainer 1b fixed to the main tank 1 and bolts (not shown) screwed to the retainer 1b. It should be noted that the reference tank 2 is arranged not to be housed in the main tank 1 but to be joined so that only the front end portion of the reference tank 2 is joined to the opening 1 a and the remaining portion projects outward from the main tank 1. Good.

An actuator 30 is housed in the reference tank 2 as shown in FIG. The actuator 30 of this embodiment is an electrodynamic device that converts an electrical signal into mechanical vibration of the diaphragm 31. The diaphragm 31 is supported by the opening of the reference tank 2 via the edge 31 a, and the movable coil 32 is attached to the center of the diaphragm 31. Further, the core 33 and the permanent magnet 34 joined to the core 33 are fitted in the reference tank 2, and the movable coil 3 is attached to the core 33.
2 is arranged so as to be movable in the axial direction of the reference tank 2. A communication hole 33 a is formed in the center of the core 33, and the cover 4 and the diaphragm 31 define a space RS in the reference tank 2. A communication hole 2a having a small diameter is formed in the side wall of the reference tank 2 so that the space RS in the reference tank 2 communicates with the space MS in the main tank 1.

When a drive signal of an alternating voltage is supplied to the movable coil 32, the diaphragm 31 vibrates, and the space MS in the main tank 1 and the space RS in the reference tank 2 are reversed at the same time. A phase compressional pressure wave is output. It should be noted that the actuator 30 is not limited to the above, but a coil is wound around a core connected to a permanent magnet, and an electromagnetic type device that vibrates the diaphragm 31 by supplying a drive signal to the coil is configured. Good. In addition, various configurations such as an electrostatic type, an electrostrictive type, and a magnetostrictive type used in the field of speakers can be adopted, or a device for driving a piston or the like can be adopted.

At the open end of the reference tank 2, there is provided a pressure sensor 10 which constitutes the first pressure fluctuation detecting means of the present invention and which is exposed to the space MS in the main tank 1 and detects the pressure fluctuation in the space MS. It is installed. Further, a pressure sensor 20 which constitutes a second pressure fluctuation detecting means of the present invention and detects a pressure fluctuation of the space RS in the reference tank 2 is supported in the reference tank 2. Thus, these pressure sensors 10, 20
To the space M of each of the main tank 1 and the reference tank 2
A detection signal corresponding to the pressure fluctuation values of S and RS is output to the controller 50. The pressure sensors 10 and 20 convert a pressure signal into an electric signal and have various modes such as a microphone. The space surrounded by the case 5 and the cover 4 accommodates circuit elements and the like constituting the controller 50, and the pressure sensors 10 and 20 are connected to the controller 5 by the controller 5.
It is connected to 0.

The controller 50 has a circuit configuration shown in the upper part of FIG. 2, and has first and second band pass filters (BPF) 11 and 2 connected to the pressure sensors 10 and 20, respectively.
1. A / D converter 12 and 22 and CPU
(Central processing unit) 51, each memory of ROM 52 and RAM 53, timer 54, input / output interface 55, etc. are built-in, and the drive circuit 40 is connected to this input / output interface 55, and this drive circuit 40 allows the actuator 30 to move. It is connected to the coil 32. Further, a display device 60 is connected to the input / output interface 55. As the display device 60, there are various modes such as a fuel gauge of analog display or digital display.

The drive circuit 40 is, for example, an oscillator (not shown).
A built-in, a predetermined frequency according to the output signal of the output interface 55 (e.g., 10H _Z) is configured to provide a sine wave output signal of the moving coil 32 of the actuator 30, the main tank 1 and the reference tank 2 The actuator 30 is drive-controlled so that a gas volume change of, for example, | v ₀ sinω ₀ t | Note that v
₀ is the maximum value of the gas volume change caused by the compression and compression pressure waves output from the diaphragm 31.

The detection signals of the pressure sensors 10 and 20 described above are supplied to the first and second bandpass filters 11 and 21, where the signal component of the angular frequency ω ₀ is extracted and A /
It is converted into a digital amount through the D converters 12 and 22 and supplied to the input / output interface 55.

Further, a vehicle V equipped with the main tank 1
H is a vehicle speed sensor 81 that detects a vehicle speed (hereinafter simply referred to as a vehicle speed), a rotation speed sensor 82 that detects an engine speed, and an acceleration sensor 8 that detects a suspension acceleration as a factor indicating a vibration state of the vehicle VH.
3 is provided, and these detection signals are connected so as to be input to the input / output interface 55. Therefore, these sensors 81, 82, 83 constitute the moving state detecting means according to the present invention.

In the controller 50, input / output processing, storage, and calculation are performed according to the detection signals of the pressure sensors 10 and 20, the actuator 30 is driven, and the calculation result is output to the display device 60. It That is,
The actuator 30 is driven according to a program executed by the CPU 51, and the volume of the space in the main tank 1
As a result, a series of arithmetic processing for obtaining the remaining fuel amount in the main tank 1 is performed, and the remaining fuel amount is displayed on the display device 60. This program consists of, for example, the routines shown in FIGS. 3 and 4, is executed after the ignition switch (not shown) is turned on, and is processed as follows.

First, in step 101, the CPU 51
Are initialized, various calculated values are cleared, counters (A, B) described later are cleared (A = 0, B = 0), and the error Er is cleared (Er = 0). Then, step 1
At 02, the matrix array values stored in the memory are initialized. Here, the matrix generally means a map (or a table) forming a two-dimensional array using, for example, the vehicle speed Vs of the vehicle VH and the engine speed Ne as parameters, and in the present embodiment, the suspension acceleration Ac is further used as parameters. In addition, the configuration is as shown in FIG. The data stored in each matrix array is called a matrix array value or matrix value. In FIG. 5, Vn means the current vehicle speed, and other parameters (Ne, Ac) are based on this vehicle speed Vn.
Is set. Similarly, the other two parameters are set for each of the engine speed Ne and the suspension acceleration Ac.

Then, in step 103, the drive circuit 4
The actuator 30 is driven according to the output from 0,
The vibrating plate 31 starts to vibrate, and the dense and dense pressure waves are output to the space MS in the main tank 1 and the space RS in the reference tank 2. As a result, substantially the same pressure fluctuations (but opposite phases) occur in the respective spaces MS and RS under substantially the same conditions.

The pressure fluctuations in the spaces MS and RS are detected by the pressure sensors 10 and 20, and the amount of change is the pressure fluctuation value ΔP _M in the main tank 1 and the reference tank 2.
Calculated as ΔP _R. The latter ΔP _R can be expressed as the following formula (1), and the former ΔP _M can be expressed as the following formula (2).

ΔP _R = γ · (P ₀ · V ₀ / V _R ) · sin (ω ₀ t + φ _R ) ... (1)

ΔP _M = γ · (P ₀ · V ₀ / V _M + ΔV _A ) · sin (ω ₀ t + φ _M ) ... (2)

Where γ is the specific heat ratio of the gas in the main tank 1 and the reference tank 2, P ₀ is the absolute pressure in the main tank 1 and the reference tank 2, and V _R is the volume of the space RS in the reference tank 2. , V _M represents the volume of the space MS in the main tank 1, and ΔV _A represents the volume change amount of the space MS due to the deformation of the main tank 1 due to the driving of the actuator 30.

Proceeding to step 104, the pressure sensor 10,
The detection signal of 20 is converted into a digital amount through the A / D converters 12 and 22, and the input / output interface 55
It is stored in the RAM 53 via. And step 1
At 05, the absolute values of the pressure fluctuation values ΔP _R and ΔP _M are integrated for a predetermined time and stored in the memory, and the routine proceeds to step 106. In step 106, the signal indicating the state of the vehicle VH in which the main tank 1 is installed is the controller 50.
And is stored in the RAM 53. In this embodiment, as a signal representing the state of the vehicle VH, the vehicle speed V is as described above.
s, engine speed Ne and suspension acceleration Ac
Is used to form a matrix array having these as parameters.

Then, in step 107, the ratio λ (= ΔP) of the pressure fluctuation values ΔP _R and ΔP _M integrated as described above.
_R / ΔP _M ) is calculated. This ratio λ is the ratio of the sum of the volume V _M of the space MS in the main tank 1 and the volume change amount ΔV _A to the volume V _R of the space RS in the reference tank 2 (= (V _M +
ΔV _A ) / V _R ). Then, step 108
Then, the remaining fuel amount in the main tank 1 (hereinafter referred to as the liquid amount V _L ) is calculated according to the value of the ratio λ. For example, the ratio λ
A linear function F (λ) = ab−λ having a variable is used, and the liquid volume _VL is calculated with _VL = ab−λ. However, both a and b are constants, a is the capacity (total volume) of the main tank 1, and the constant b is set by actually measuring the ratio λ of pressure fluctuation values at a predetermined liquid volume V _L0 .

Next, at step 109, based on the matrix constructed at step 106, the matrix value corresponding to the vehicle state is set as the correction value V _A. Then, the process proceeds to step 110, the liquid volume V _L obtained in step 108 is corrected by the correction value V _A (V _L -
V _A ). The liquid volume V _L corrected in this way is used as a display value, and a predetermined display is performed in step 111. The volume V _M of the space MS in the main tank 1 may be displayed, or the output signal of the input / output interface 55 may be directly provided to another control device or the like without providing the display device 60. Good.

Subsequently, the routine proceeds to step 112 in FIG. 4, where the current liquid amount (display value) V _Ln (the latest liquid amount V _L obtained in step 110 is taken as V _Ln ) and the previous liquid amount (display). value)
The difference of _{VL (n-1)} is obtained, and the difference E is calculated in step 113.
r is compared with a predetermined value Kr. That is, the difference Er is the predetermined value K
When it is determined that r is exceeded, the process proceeds to step 114, 115, or 116, and each parameter of the matrix is corrected if a predetermined condition is satisfied, respectively, but when it is determined that the value is not more than the predetermined value Kr, the process directly returns to step 104.

In step 114, the vehicle speed Vs is compared with a predetermined value Ks, and if it exceeds this, step 20
The matrix correction is performed according to 1 to 207, but when the speed is equal to or lower than the predetermined speed, the routine proceeds to step 115, where the engine speed Ne is compared with the predetermined value Ke. If the engine speed Ne exceeds the predetermined value Ke, the routine proceeds to step 200, where the matrix correction is performed, but if it is below the predetermined value Ke, the routine proceeds to step 116. At step 116, the suspension acceleration Ac is the predetermined value Kc.
If it exceeds this value, matrix correction is performed in step 200, but if it is below the predetermined value Kc, the process directly returns to step 104.

The processing contents of the matrix correction of step 200 performed after steps 115 and 116 are the same as the processing of steps 201 to 207 (however, in step 202, Ne or Ac is used instead of Vs, respectively). ), Will be described below. First, the vehicle speed Vs
When the value exceeds the predetermined value Ks, the counters (A) and (B) are set to 1 in step 201, respectively,
The predetermined routine is repeated until the respective counters reach the predetermined values m and n, respectively. That is, in step 202, all the other two parameters (parameters represented by array element numbers A and B) are updated based on the current vehicle speed Vs.

This is done with respect to each parameter having the relationship as shown in FIG. 5, with reference to the current vehicle speed Vs as a step 2
The array (Vs, 1, 1) = [array (V
s, 1,1) + Er] / 2, array (Vs, 1, n)
= [Array (Vs, 1, n) + Er] / 2,
Further, in steps 202 to 207, the array (Vs, m, n) is arranged.
= [Array (Vs, m, n) + Er] / 2 is sequentially updated. The counter (B) is incremented (+1) in step 203, and the counter (B) is compared with a predetermined value n in step 204. When the counter (B) exceeds the predetermined value n, the counter (B) is set to 1, then the counter (A) is incremented (+1) in step 206, and the counter (A) is set to the predetermined value m in step 207. Is compared with the predetermined value m, and if it is equal to or less than the predetermined value m
Return to 2.

As described above, according to this embodiment, the parameters of the matrix are updated according to the difference between the measurement results of this time and the previous time, and the learning control is performed by the controller 50. That is, the correction value is updated according to the change in the moving state of the moving body. In this embodiment, the error is corrected on the condition that the vehicle speed Vs or the like exceeds a predetermined value, but it may be corrected at regular intervals. The updating method is not limited to the above, and various means may be used as appropriate. Although the fluid amount measuring device for measuring the remaining amount of fuel is used in this embodiment, the device for measuring the contained amount of powder, granules, deformed objects, etc. is not limited to fuel.

[0034]

Since the present invention is configured as described above, it has the following effects. That is, according to the fluid amount measuring method of claim 1, the moving state of the moving body is detected, a correction value is set according to the detection result, and the calculation result of the fluid amount in the main tank is calculated based on the correction value. Since the correction value is updated according to the change of the moving state of the moving body, it is possible to suppress the measurement error due to the change of the moving state of the moving body and to secure the stable measurement accuracy. can do.

Further, in the fluid amount measuring device according to the second aspect, the moving state of the moving body is detected by the moving state detecting means, the correction value is set by the correction value setting means according to the detection result, and the correction value is corrected. Since the correction means corrects the calculation result of the fluid amount calculation means on the basis of the value, and the correction value is updated by the updating means according to the change in the moving state of the moving body, the movement of the moving body is moved. It is possible to suppress the measurement error caused by the change of the state, and it is possible to secure stable measurement accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a fluid amount measuring device of the present invention.

FIG. 2 is a block diagram showing a configuration of a fluid amount measuring device according to an embodiment of the present invention.

FIG. 3 is a flowchart showing processing by a controller according to an embodiment of the present invention.

FIG. 4 is a flowchart showing processing by a controller in an embodiment of the present invention.

FIG. 5 is a diagram showing an example of a matrix according to an embodiment of the present invention.

[Explanation of symbols]

1 main tank 2 standard tank 2a communication hole 10, 20 Pressure sensor 30 actuators 31 diaphragm 32 moving coils 40 drive circuit 50 controller 60 Output device

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Nakano 1 Noda, Oguchi-cho, Oguchi-machi, Niwa-gun, Aichi Prefecture Toda Rika Electric Works Co., Ltd. 2-26, Horie Metal Industry Co., Ltd. (72) Inventor, Kuman Kato, 2 Konosu-cho, Toyota City, Aichi Prefecture 26-26 Horie Metal Industry Co., Ltd. (72) Inventor, Takashima, 2 Kounosu-cho, Toyota City, Aichi Prefecture 26-chome Horie Metal Industry Co., Ltd. (72) Inventor Naoya Kame 2-26 Konosu-cho, Toyota City, Aichi Prefecture Horie Metal Industry Co., Ltd. (56) Reference JP-A-2-206723 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01F 23/14 G01F 17/00 G01F 22/00

Claims (2)

(57) [Claims] 1. A main tank having a predetermined shape, which is mounted on a moving body and stores a fluid, a reference tank communicating with the main tank, a space in the reference tank, and a space above the fluid in the main tank. An actuator that changes each volume to give a pressure fluctuation, and drives the actuator to detect an operating state pressure fluctuation value of each of the main tank and the reference tank, and each operating state pressure fluctuation value. In the fluid amount measuring method for computing the fluid amount in the main tank according to the calculation result, detecting the moving state of the moving body, setting a correction value according to the detection result, and setting the correction value. A method for measuring the amount of fluid, wherein the calculation result of the amount of fluid in the main tank is corrected based on the above, and the corrected value is updated according to the change of the moving state of the moving body. 2. A main tank having a predetermined shape, which is mounted on a moving body and stores a fluid, a reference tank communicating with the main tank, a space in the reference tank and a space above the fluid in the main tank. An actuator that applies pressure fluctuation by changing each volume, a drive unit that drives the actuator, and a first pressure fluctuation detection unit that detects a pressure fluctuation value in a space above the fluid in the main tank, Second pressure fluctuation detecting means for detecting a pressure fluctuation value in the space inside the reference tank, and the main tank and the reference tank detected by the first and second pressure fluctuation detecting means while the actuator is operating. Pressure ratio calculating means for calculating the ratio of the respective operating state pressure fluctuation values, and the amount of fluid in the main tank according to the calculation result of the pressure ratio calculating means. , A moving amount detecting unit for detecting a moving state of the moving body, a correction value setting unit for setting a correction value according to a detection result of the moving state detecting unit, and the correction value setting unit. A correction means for correcting the calculation result of the fluid amount calculation means based on the correction value set by the means; and an updating means for updating the correction value according to a change in the moving state of the moving body. Fluid volume measuring device.