JP2012052942A - Gravity center position measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gravity center measuring device capable of measuring a horizontal gravity center position of a vehicle, with a simple and inexpensive structure.SOLUTION: The gravity center measuring device comprises a measuring placing stand 13 on which all right and left wheels of a vehicle 3 can be placed; a plurality of load cells 21-24 for supporting the measuring placing stand 13; tread sensors 11 and 12 for detecting a relative position in a width direction of the vehicle 3 to the measuring placing stand 13, and detecting that the wheels of the vehicle 3 pass through a predetermined position; a vehicle width direction gravity center position computing portion 50 for computing a gravity center position in the width direction of the vehicle 3 on the basis of load signals from the plurality of the load cells 21-24 and a detection signal from the tread sensors 11 and 12; and a vehicle full length direction gravity center position computing portion 51 for computing a gravity center position in the full length direction of the vehicle 3 on the basis of the load signals from the plurality of the load cells 21-24 and the detection signal from the tread sensors 11 and 12.

Description

  The present invention relates to a center-of-gravity position measuring device that measures a position of a center of gravity of a vehicle projected onto a horizontal plane.

  Vehicles such as trucks and trailers not only have a large load, but also experience that the position of the center of gravity of the vehicle including the load shifts forward and backward, left and right due to the load, and moves upward to affect the running stability of the vehicle. Well known. It has also been clarified mechanically that a rollover during turning of the vehicle or at the start of turning is caused by the above three-dimensional center of gravity. Therefore, measurement of the three-dimensional barycentric position is important. A patent application has already been filed by the present applicant for the height measuring device in the three-dimensional center of gravity position (Japanese Patent Application No. 2009-183443). In this specification, the invention of a measuring device for the position of the center of gravity projected on the horizontal plane (horizontal center of gravity position) will be described.

  Conventionally, a truck scale has been widely used for measuring the weight of a vehicle such as a truck or a trailer. The track scale includes a mounting table on which a vehicle can be mounted, a plurality of load cells that support the mounting table, and a calculation device that executes predetermined calculations related to weight measurement based on load signals from the load cells. Has been.

  In the track scale configured as described above, the position of the vehicle on the platform is defined, the dimensions of the vehicle are input to the arithmetic unit, and the load signals of the individual load cells are analyzed. Can be measured (calculated) (see, for example, Patent Document 1).

However, the method for measuring the horizontal center of gravity position of a vehicle using the above-described track scale has the following problems.
(1) It takes time and attention to stop the vehicle at the specified position.
(2) It is troublesome to investigate the vehicle specifications and manually input the contents into the arithmetic device, and there is a high possibility that an input error will occur.

  On the other hand, the center of gravity in which the position of the center of gravity of the vehicle in the three-dimensional space is determined by a predetermined calculation based on a detection signal from a swing detector that detects the swing of the vehicle in its own weight direction and width direction during traveling. There exists a detection apparatus (for example, refer patent document 2).

However, the above-described center-of-gravity detection device has the following problems.
(1) Even with this device, it is necessary to input the dimensional specifications of the vehicle to the arithmetic unit, and it is troublesome to investigate the vehicle specifications and manually input the contents to the arithmetic unit, and an input error may occur. High nature.
(2) It is necessary to mount a rocking detector and an arithmetic unit in each vehicle, and enormous costs and time are required to spread it to all vehicles.

JP 2006-105845 A International Publication No. 2008/062867 Pamphlet

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a center-of-gravity position measuring apparatus that can measure the horizontal center-of-gravity position of a vehicle with a simple and inexpensive configuration. is there.

In order to achieve the above object, the center-of-gravity position measuring apparatus according to the present invention includes:
A center-of-gravity position measuring device that measures a horizontal center-of-gravity position of a vehicle,
(A) a weighing platform on which all the left and right wheels of the vehicle can be mounted;
(B) a plurality of load cells arranged at predetermined intervals in the width direction and the total length direction of the vehicle and supporting the weighing platform;
(C) vehicle width direction relative position detection means for detecting a relative position in the width direction of the vehicle with respect to the weighing platform when the vehicle is placed on the weighing platform;
(D) a wheel predetermined position passage detecting means for detecting that the vehicle wheel has passed a predetermined position when the vehicle is mounted on the weighing platform;
(E) a vehicle width direction center-of-gravity position calculating unit that calculates a center of gravity position in the vehicle width direction based on load signals from the plurality of load cells and a detection signal from the vehicle width direction relative position detecting unit;
(F) Vehicle length direction center-of-gravity position calculation means for calculating the position of the center of gravity of the vehicle in the full length direction based on load signals from the plurality of load cells and detection signals from the wheel predetermined position passage detection means. (First invention).

  In the present invention, the vehicle width direction relative position detecting means is attached to both ends of the rod-shaped member horizontally disposed in the vehicle width direction so that each wheel of the vehicle can step on and pass. It is preferable to comprise a strain gauge to be attached (second invention).

  In the present invention, the vehicle width direction relative position detecting means includes a conductive rubber extending horizontally in the width direction of the vehicle so that each wheel of the vehicle can step on and the conductive rubber is used for the vehicle. It is preferable to comprise a deformed portion when stepped on each wheel and an electric resistance wire arranged so as to be able to come into contact (third invention).

  In this invention, it is preferable that the said vehicle width direction relative position detection means is assembled | attached to the said weighing platform (4th invention).

  In this invention, it is preferable that the said weighing platform is comprised combining the some division | segmentation weighing platform arrange | positioned along the advancing direction of a vehicle (5th invention).

In the center-of-gravity position measuring apparatus of the present invention, load signals from a plurality of load cells that support the weighing platform and detection signals from a vehicle width direction relative position detecting unit that detects a relative position in the width direction of the vehicle with respect to the weighing platform. Based on the above, the center of gravity position in the vehicle width direction is calculated by the vehicle width direction center of gravity position calculating means. Thereby, the gravity center position of the width direction of a vehicle can be measured.
Further, based on load signals from a plurality of load cells that support the weighing platform and detection signals from wheel predetermined position passage detecting means for detecting that the vehicle wheel has passed a predetermined position, The gravity center position is calculated by the vehicle full length direction gravity center position calculation means. Thereby, the center-of-gravity position in the full length direction of the vehicle can be measured.
According to the center-of-gravity position measuring apparatus of the present invention, there are complicated operations such as inputting dimensions of the vehicle, which are required in the prior art, and a swing detector or an arithmetic unit separately mounted on the vehicle. It is unnecessary, and the horizontal center of gravity position of the vehicle can be measured with a simple and inexpensive configuration.

BRIEF DESCRIPTION OF THE DRAWINGS It is structure explanatory drawing of the gravity center position measuring apparatus which concerns on the 1st Embodiment of this invention, AA sectional view taken on the line (a) of (a), (b), BB sectional drawing of (b) (C) Section C enlarged view (a) of FIG. 1 (c) and DD (D'-D ') line sectional view (b) of (a). Schematic system configuration diagram of the control system of the center-of-gravity measurement apparatus of the first embodiment Microprocessor functional block diagram Definition of coordinate system for horizontal position of center of gravity of vehicle and center of gravity position measuring device A figure showing how the vehicle is placed on the weighing platform A diagram showing how the load changes when the vehicle is placed on the weighing platform The flowchart explaining measurement operation | movement of the gravity center position measuring apparatus of 1st Embodiment. FIG. 6 is a structural explanatory diagram of a pressure-sensitive rubber / electric resistance wire type tread sensor equipped in the center-of-gravity position measuring apparatus according to the second embodiment, and is a view E (a) and (a) of FIG. -E line sectional view (free state diagram) (b) and (a) sectional view taken along line EE, conductive rubber compression state diagram (c) It is a schematic diagram illustrating the principle of a pressure sensitive rubber / electric resistance wire type tread sensor, and is equivalent to a free state diagram (a), an operation state diagram (b), an equivalent circuit diagram (c) and (b). Circuit diagram (d) It is structure explanatory drawing of the gravity center position measuring apparatus which concerns on the 3rd Embodiment of this invention, FF sectional view taken on the plane (a) and (a), (b), GG sectional view taken on the line (b) (C) It is structure explanatory drawing of the gravity center position measuring apparatus which concerns on the 4th Embodiment of this invention, HJ sectional view (b) of a top view (a) and (a), The J section enlarged view (c) of (b) ), Simplified diagram (b) and mechanical equivalent diagram (d) of (b) for explaining force balance The figure showing a state where a vehicle is mounted on a weighing platform formed by combining divided weighing platforms A diagram showing the state of load change when a vehicle is placed on a weighing platform in which divided weighing platforms are combined.

  Next, specific embodiments of the center-of-gravity position measuring apparatus according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a structural explanatory view of the center-of-gravity position measuring apparatus according to the first embodiment of the present invention, and is a cross-sectional view taken along the line A-A in FIGS. A cross-sectional view (c) along line -B is shown. Further, FIG. 2 shows an enlarged view (a) of the C part in FIG. 1C and a cross-sectional view along line DD (D′-D ′) in FIG.

<Description of Schematic Configuration of Center of Gravity Position Measuring Device According to First Embodiment>
The center-of-gravity position measuring apparatus 1 shown in FIG. 1 includes a first tread sensor 11, a second tread sensor 12, and a weighing platform 13.
The first tread sensor 11 and the second tread sensor 12 are disposed on the installation base 2 on the upstream side of the travel route when the vehicle 3 such as a truck or a trailer travels forward.
The weighing platform 13 is disposed on the downstream side of the forward travel path of the vehicle 3 with respect to the first tread sensor 11 and the second tread sensor 12 on the installation base 2.
In the present embodiment, the vehicle 3 has one axle 7, 8, 9 with wheels 4 a, 5 a, 6 a; 4 b, 5 b, 6 b mounted on the left and right respectively, below the driver's seat and below the loading platform. This is a three-axis vehicle having two, three in total (see FIG. 5).
In the following description, the front-rear and left-right directions are determined based on the forward direction of the vehicle 3.

<Description of the first tread sensor and the second tread sensor>
The first tread sensor 11 and the second tread sensor 12 have basically the same structure. As a representative, the structure of the first tread sensor 11 will be described, and the structure of the second tread sensor 12 will be described with the structure description of the first tread sensor 11.
As shown in FIG. 2A, the first tread sensor 11 is horizontally arranged in the width direction of the vehicle 3 so that the left wheels 4a, 5a, 6a of the vehicle 3 can be stepped on. A rod-shaped member 31 is provided. This rod-shaped member 31 is embedded in the road surface GL on the near side of the weighing platform 13 on the traveling path of the vehicle 3. The rod-shaped member 31 is composed of a metal rod having a rectangular cross section, and both ends thereof are supported by the support member 32.
As shown in FIG. 2 (b), in both end portions of the rod-shaped member 31, recess portions 33a, 33a; 34a, 34a that are hollowed out from both sides are formed. Further, a partition plate portion 35; 35 is formed so as to partition the recess portions 33a, 33a; 34a, 34a on both sides, and strain gauges 36, 37 for detecting shear strain are bonded to the partition plate portion 35; 35. Has been.
In short, the first tread sensor 11 is a kind of load cell in which strain gauges 36 and 37 are bonded to both ends of a metal rod-shaped member 31.
In the first tread sensor 11, when the rod-shaped member 31 is stepped on the wheels 4 a, 5 a, 6 a, the wheels 4 a, 5 a, 6 a cause the tread sensor 11 (rod-shaped member 31) to be detected by signals from the strain gauges 36, 37. It is possible to detect the stepping on and to determine the position where the wheels 4a, 5a and 6a are stepped on as a relative position to the two strain gauges 36 and 37 based on the load difference detected by the two strain gauges 36 and 37. It has become.

<Description of weighing platform>
The weighing platform 13 is composed of a rectangular plate-like member on which all the left and right wheels 4a, 5a, 6a; 4b, 5b, 6b of the vehicle 3 can be placed simultaneously.

<Arrangement description of first to fourth load cells>
A first load cell 21, a second load cell 22, a third load cell 23, and a fourth load cell 24 are interposed between the installation base 2 and the weighing platform 13, respectively.
The first load cell 21 is arranged so that the left corner of the weighing platform 13 on the upstream side of the vehicle traveling path can be supported from below.
The second load cell 22 is arranged so that the left corner of the weighing platform 13 on the downstream side of the vehicle traveling path can be supported from below.
The third load cell 23 is arranged so that the right corner of the weighing platform 13 on the upstream side of the vehicle traveling path can be supported from below.
The fourth load cell 24 is arranged so that the right corner of the weighing platform 13 on the downstream side of the vehicle traveling path can be supported from below.

<Functional description of each load cell>
Each of the load cells 21 to 24 is a strain gauge type load cell, and has a function of converting an applied load into an electrical load signal according to its magnitude and outputting the signal.

<Description of system configuration of control system of center of gravity position measuring device>
As shown in FIG. 3, the center-of-gravity measurement device 1 includes a control device 40, an operation device 41, and a display device 42.

<Overview of control device>
The control device 40 is mainly composed of an amplifier 43, a low-pass filter 44, a multiplexer 45, an A / D converter 46, an I / O circuit 47, a memory 48, and a microprocessor (MPU) 49. Yes.
The amplifier 43 has a function of amplifying a signal to be sent to a size that can be A / D converted and sending it out.
The low-pass filter 44 has a function of passing only a low frequency as a signal.
The multiplexer 45 has a function of selectively sending out a plurality of signals to be sent based on a command of the selection control signal.
The A / D converter 46 has a function of converting an analog signal from the multiplexer 45 into a digital signal.
The I / O circuit 47 has a function of exchanging various signals and data among the A / D converter 46, the operation device 41, the display device 42, the memory 48, and the MPU 49.
The memory 48 includes a PROM, a RAM, and the like, and has a function of storing a predetermined program, basic data, and the like for a long period of time, and temporarily storing various data, numerical values for calculation, and the like.
The MPU 49 receives a necessary signal through the I / O circuit 47 and receives necessary data from the memory 48 in accordance with an instruction of a predetermined program stored in the memory 48, and performs an operation based on the received signal and data. Has the function to execute.

<Overview of operating device>
The operation device 41 includes operation switches, numerical keys, and the like, and is used for various operations such as measurement start / end commands, zero point adjustment, use mode switching, and numerical setting.

<Overview of display device>
The display device 42 is composed of a liquid crystal display, for example, and displays measurement results and various data input / output screens.

<Outline of processing operation of control system of centroid position measuring device>
In the control system of the center-of-gravity measurement device 1, the signals of the load cells 21 to 24 and the tread sensors 11 and 12 are supplied to the amplifier 43, the low-pass filter 44, the multiplexer 45, the A / D converter 46, and the I / O circuit 47. Via MPU 49. The MPU 49 takes in a signal from the I / O circuit 47 according to a predetermined program stored in the memory 48, reads various data stored in the memory 48, and based on these signals and data, The horizontal center of gravity is calculated. The calculation result is displayed on the display device 42.

<Functional description of control device>
In the MPU 49, the functions of the vehicle width direction gravity center position calculation unit 50, the vehicle full length direction gravity center position calculation unit 51, and the output signal generation unit 52 shown in FIG. .

<Theoretical explanation of how to obtain the coordinates (X _G , Y _G ) of the center of gravity G of the vehicle>
Next, how to obtain the coordinates (X _G , Y _G ) of the center of gravity G of the vehicle 3 will be described mainly with reference to FIGS.
Cartesian coordinates with the X axis defined along the vehicle center line passing through the center position in the width direction of the vehicle 3 and extending in the full length direction, the Y axis defined along the first axle 7, and the intersection of the X axis and Y axis as the origin Define the system O-XY.
The x-axis is defined along the width direction center line extending in the full length direction through the center position in the width direction of the weighing platform 13, and along the center line in the length direction extending in the width direction through the center position in the length direction of the weighing table 13 Then, the y-axis is determined, and the orthogonal coordinate system o-xy is determined by taking the origin at the intersection of both axes, that is, at the center of the weighing platform 13.
Assume that the output of each of the load cells 21 to 24 is adjusted to zero when there is no load.

<Explanation of symbol definitions (vehicle-related)>
The meanings of symbols used in the figure and in the theoretical formula are defined as follows.
G: Center of gravity of vehicle 3 i (= 1, 2,..., K): Axle number k: Number of axles (k ≧ 2)
X _G : Center of gravity position in the full length direction of the vehicle 3 in the coordinate system O-XY Y _G : Centroid position in the width direction of the vehicle 3 in the coordinate system O-XY x _G : Center of gravity in the full length direction of the vehicle 3 in the coordinate system o-xy Position y _G : Position of the center of gravity of the vehicle 3 in the coordinate system o-xy B, B _i : Effective tread interval Here, the tread interval is the left and right wheels 4a, 5a, 6a; 4b, 5b, This is the distance between the centers of 6b, that is, the wheel distance.
l _j : Distance between axles j (= 1, 2,..., k−1): Number between axles (k ≧ 2)
e: Distance from the X axis of the center of gravity position of the vehicle (= Y _G )

<Explanation of symbol definitions (related to load cells)>
LC1: first load cell 21
LC2: second load cell 22
LC3: Third load cell 23
LC4: Fourth load cell 24
a: Center-to-center distance between the first load cell 21 (third load cell 23) and the second load cell 22 (fourth load cell 24) b: First load cell 21 (second load cell 22) and third load cell 23 (fourth load cell 24) Note that among the above symbols, a and b are known values, and these values are stored in the memory 48 in advance.

<Description of symbol definition (relative position relation between vehicle and platform)>
f: Distance between X axis and x axis

<Explanation of symbol definitions (mechanics)>
W _Li : Wheel load (left side)
W _Ri : Wheel load (right side)
W _i : Axial weight of the i-th axis W: Total weight P _i : Force acting on the i-th load cell (= force acting on the platform from the load cell)
P _j : force acting on the jth load cell (= force acting on the platform from the load cell)
P _ij : P _i + P _j
P = P ₁ + P ₂ + P ₃ + P ₄
t: Time when the first axle 7 is located at the center of the first tread sensor 11 or the second tread sensor 12 in the vehicle traveling direction. The origin t _i : The i th axle is the first tread sensor 11 or the second tread sensor 11. Time when the tread sensor 12 is in the center of the vehicle traveling direction τ _i : Time when the axle load W _i of the i-th axle is loaded on the weighing platform 13

<Explanation of symbol definitions (related to tread sensors)>
c: Distance between first tread sensor 11 and first load cell 21 (distance between second tread sensor 12 and third load cell 23)
S ₀ : Distance from the center line 38 to the strain gauge 36 S ₁ : Distance between the strain gauge 36 and the center of the tread width of the left wheels 4a, 5a, 6a S ₂ : Tread of the strain gauge 37 and the left wheels 4a, 5a, 6a Distance from the center of the width S ₃ : Distance between the strain gauge 36 and the strain gauge 37 S: Distance from the center line 38 to the center of the tread width of the left and right wheels 4a, 5a, 6a; 4b, 5b, 6b S _L : No. S by 1 tread sensor 11
S _R : S by the second tread sensor 12
Of the symbols, c, S ₀ , and S ₃ are known values, and these values are stored in the memory 48 in advance.

<Explanation of measurement of X _G and l _j : See FIGS. 6 and 7>
6 (a) to 6 (d) are diagrams showing in stages how the vehicle 3 is placed on the weighing platform 13, and FIG. 7 is a diagram showing how the load changes at each stage. ing.
For the measurement of X _G, it is essential to measure the _{l j.} Further, l _j can be obtained based on outputs P ₁ (t) to P ₄ (t) of the first load cell 21 to the fourth load cell 24.

<Description of how to obtain l ₁ and l ₂ >
(1) Formula for calculating the distance between axles The distance between axles l ₁ and l ₂ is the time detected by the first tread sensor 11 or the second tread sensor 12 being stepped on the i-th wheel, and each time t = t _i It is calculated using the measured values _P 24 (t) and _{W i} of the load of the load cell 22, 24 in.

l ₁ of the calculation formula:
At t = t ₂ (see FIG. 6 (c)), the moment balance equation with the load cells 21 and 23 as fulcrums is expressed by the following equation (1).
aP ₂₄ (t) -x ₁ W ₁ = 0 (1)
Since x ₁ = l ₁ −c, l ₁ can be obtained from the following equation (2).
l ₁ = aP ₂₄ (t) / W ₁ + c (2)

Formula for calculating l ₂ :
At t = t ₃ (see FIG. 6D), the balance equation of moments with the load cells 21 and 23 as fulcrums is expressed by the following equation (3).
aP ₂₄ (t) -x ₁ W ₁ -x ₂ W ₂ = 0 (3)
x ₁ = l ₁ + x ₂ and
Since x ₂ = l ₂ −c, l ₂ is obtained from the following equation (4).
l ₂ = (aP ₂₄ (t) −l ₁ W ₁ ) / (W ₁ + W ₂ ) + c (4)

ここで、Ｐ（ｔ）は、次式（６）で表わされる。
Ｐ（ｔ）＝Ｐ_１３（ｔ）＋Ｐ_２４（ｔ） ・・・（６）
また、Ｗ_０＝０、τ_ｉ＜ｔ＜τ_ｉ＋１、ｉ＝１，２およびｔ＞τ_ｉ，ｉ=３である。 (2) Measurement of axle load Among the calculation formulas of l ₁ represented by the formula (2) and the calculation formulas of l ₂ represented by the formula (4), P ₂₄ (t) indicates that each wheel is a tread sensor 11. , is determined by the load _{P 24} at the time of the load cell 22, 24 stepped on 12. Further, each axial weight _Wi is obtained by the following equation (5) based on the overall load change as shown in FIG.

Here, P (t) is expressed by the following equation (6).
P (t) = P ₁₃ (t) + P ₂₄ (t) (6)
In addition, W ₀ = 0, τ _i <t <τ _{i + 1} , i = 1, 2 and t> τ _i , i = 3.

<Determination of the description of _{X G>}
Assuming that the first wheel 7 of the vehicle 3 is the origin O, a general formula for balancing moments around the origin O is expressed by the following formula (7). Here, _XG is negative.
_XG W + W ₂ l ₁ + W ₃ (l ₁ + l ₂ ) +... + W _n (l ₁ + l ₂ +... + L _n-1 ) = 0
... (7)
From the above equation (7), _XG is obtained by the following equation (8).
X _G = − {W ₂ l ₁ + W ₃ (l ₁ + l ₂ ) +... + W _n (l ₁ + l ₂ +... + L _n−1 )} / W
... (8)
here,
W = W ₁ + W ₂ +... + W _n
W _i = shaft weight (i = 1, 2,..., N)
n: Number of axles l _i : Distance between shafts.
Then, in the formula (8), at the n = 3, X-direction center-of-gravity position X _G of the vehicle 3 of a three-axis shown in FIG. 5 is obtained.

<Description of the method of obtaining the _{Y G>}
In FIG. 5, when the output of each load cell 21-24 is adjusted to zero in the state where there is no load (vehicle 3) on the weighing platform 13, and the output sensitivity of each load cell 21-24 is equal, The center-of-gravity position y _G in the system o-xy can be obtained by the following equation (9) using the outputs P ₁ , P ₂ , P ₃ , and P ₄ of the load cells 21 to 24.
y _G = (P ₁ + P ₂ ) b / W−b / 2 (9)
However, W = P ₁ + P ₂ + P ₃ + P ₄ .
W may be measured after all the axles 7, 8, and 9 have been placed on the weighing platform 13. The calculation performed using each measurement value does not need to be performed in real time, and may be performed after being stored in the memory 48 and subjected to waveform processing at a necessary timing.

<Description of measurement of relative position of vehicle in width direction with respect to weighing platform>
As shown in FIGS. 1C and 2A, the first tread sensor 11 and the second tread sensor 12 are installed symmetrically with the center line 38 of the weighing platform 13 in between. As described above, the first tread sensor 11 and the second tread sensor 12 have the same structure. In FIG. 2A, only the first tread sensor 11 is illustrated, and the second tread sensor 12 is not illustrated. To do.

Now, for example, the left wheels 4a, 5a, the 6a depresses the rod-shaped member 31 of the first tread sensor 11, the wheel 4a of the left side strain gauge 36 and 37 parts, 5a, 6a load (wheel load) _{W L-consuming} Are distributed at the ratios shown in the following equations (10) and (11).
Force detected by the strain gauge 36 F ₃₆ = W _L1 S ₂ / S ₃ (10)
Force detected by the strain gauge 37 F ₃₇ = W _L1 S ₁ / S ₃ (11)
From these formulas (10) and (11), F ₃₆ / F ₃₇ = S ₂ / S ₁ , and when F ₃₆ and F ₃₇ are measured, the grounding points of the left wheels 4a, 5a, and 6a with respect to the strain gauge distance S ₃ The distances S ₁ and S ₂ can be calculated.
Here, the gauge distance _{S 3} strain, the distance between the gauge 37 and the strain strain gauge 36, the distance _{S 1} is the distance between the strain gauge 36 left wheel 4a, 5a, and a tread width center of 6a, the distance _{S 2} is the distance of the strain gauge 37 left wheel 4a, 5a, and a tread width center of 6a.
In addition, since the distance S ₀ from the center line 38 of the two tread sensors 11 and 12 (= the center line of the weighing platform 13) to the strain gauge 36 is determined by design, the left side of the center line 38 is calculated by calculation. A distance S to the center of the tread width of the wheels 4a, 5a, 6a is obtained. Although the above has described the first tread sensor 11 on the left side in the vehicle traveling direction, the same can be said for the second tread sensor 12 on the right side in the vehicle traveling direction.

If the respective S (= S ₁ + S ₀ ) of the first tread sensor 11 and the second tread sensor 12 are summed, the tread interval B can be obtained. Then, when SB / 2 is calculated, the Y-direction position deviation f of the vehicle 3 is obtained.
By the way, the tread interval B _j is obtained for each of the axles 7, 8, and 9, but one value (= B) determined based on the determination method of B _j is used for calculating f. A method for determining B _j will be described later.
When S by the first tread sensor 11 is written as S _L and S by the second tread sensor 12 is written as S _R , the following expressions (12), (13), (14), and (15) are established.
S _L = S _L1 + S ₀ (12)
S _R = S _R1 + S ₀ (13)
B = S _L + S _R (14)
f = S _L −B / 2 (15)
Then, the gravity center position Y _G in the Y direction of the vehicle 3 can be obtained by the following equation (16).
Y _G = y _G −f (16)

The width dimension of the tread sensors 11 and 12 of this structure in the vehicle traveling direction is small, and the tread surfaces of the wheels 4a, 5a and 6a; 4b, 5b and 6b straddle the road surface GL in the vehicle traveling direction of the tread sensors 11 and 12, The entire wheel load is not applied to the tread sensors 11 and 12. However, the absolute value of the load is not necessary for determining the position of the tread and the tread interval B of the wheels 4a, 5a, 6a; Since the measurement accuracy of wheel load is not required, this structure can be put to practical use.
In FIG. 2 and the explanation thereof, the strain gauges 36 and 37 are attached to both ends of the metal rod-shaped member 31 to manufacture the load cell as a single type, but it is not necessary to stick to this structure. You may employ | adopt the structure of receiving the both ends of a simple rod-shaped member with a normal load cell.
In addition, a spring or the like is interposed in the load cell mounting portion of the tread sensor 11 or 12 or the structure received by the load cell described above, and when the load exceeds a certain level, the spring or the like is bent and the sensor exceeds the limit. Even if the structure has a heavy load, there is almost no change in the aforementioned functions and accuracy. By doing so, the tread sensors 11, 12 themselves can be reduced in weight and made inexpensive.

<Description of measurement operation of center of gravity position measuring device>
Next, the measurement operation of the center-of-gravity position measuring apparatus 1 will be described below mainly using the functional block diagram of FIG. 4 and the flowchart of FIG. In FIG. 8, symbols “S” and “T” each represent a step.

<Description of Processing Contents of Step S1>
The vehicle width direction center-of-gravity position calculation unit 50 reads the tread detection signals of the first tread sensor 11 and the second tread sensor 12, and calculates the effective tread width B based on the read detection signals and the equation (14). At the same time, the Y-direction deviation f of the vehicle 3 is calculated based on the obtained value of the effective tread width B and the equation (15).
Further, while the computing the entire y-direction centroid position y _G that the weighing load platform 13 combined vehicle 3 on the weighing the platform 13 on the basis of the load signal from the load cell 21 to 24.
Further, the vehicle center-of-gravity position Y _G is determined from y _G and the Y-direction deviation f of the vehicle 3 using the equation (16).

<Description of Processing Contents of Step S2 to Step S3>
Then, the output signal generation unit 53 generates a display signal for displaying the calculation result by the vehicle width direction gravity center position calculation unit 50 on the display device 42, and transmits the display signal to the display device 42 (S2). Thereby, the value of the barycentric position in the width direction of the vehicle 3 is displayed on the display device 42 (S3). The center of gravity of the vehicle width direction Y _G and the tread width B is output as signals simultaneously.

<Description of Processing Contents of Step T1 to Step T3>
The vehicle full length direction center-of-gravity position calculation unit 51 reads the detection signals of the first tread sensor 11 and the second tread sensor 12 and also reads the load signals of the load cells 21 to 24, and the read signal and the above equation (2). On the basis of (4), the inter-axle distances l ₁ and l ₂ are calculated, and on the basis of the calculated values of the inter-axle distances l ₁ and l ₂ and the equation (8), the coordinate system O− computing a center-of-gravity position _{X G} in the overall length direction of the vehicle 3 in the XY (T1).
Then, the output signal generation unit 53 generates a display signal for causing the display device 42 to display the calculation result by the vehicle full length direction gravity center position calculation unit 51, and transmits the display signal to the display device 42 (T2). Thereby, the value of the gravity center position of the vehicle 3 in the full length direction is displayed on the display device 42 (T3). Further, a signal of the calculation result is output.

<Description of Effects of the Center of Gravity Position Measuring Device of the First Embodiment>
According to the center-of-gravity position measuring apparatus 1 of the first embodiment, the horizontal center-of-gravity position G (X _G , Y _G ) of the vehicle 3 can be measured with a simple and inexpensive configuration, which contributes to preventing the vehicle 3 from rolling over. Effective data can be provided to the driver or the like.

[Second Embodiment]
FIG. 9 is a structural explanatory view of a pressure-sensitive rubber / electric resistance wire type tread sensor equipped in the center-of-gravity position measuring apparatus according to the second embodiment. A sectional view taken along line EE in (a) shows a free state diagram (b) and a sectional view taken along line EE in FIG.
FIG. 10 is a schematic diagram for explaining the principle of the pressure sensitive rubber / electric resistance wire type tread sensor, and is an equivalent circuit diagram (c) of a free state diagram (a), an operation state diagram (b), and (a). ) And (b) are respectively shown in equivalent circuit diagrams (d).
The center-of-gravity position measuring apparatus 1A according to the second embodiment replaces the strain gauge type tread sensors 11 and 12 provided in the center-of-gravity position measuring apparatus 1 according to the first embodiment with a pressure-sensitive rubber / electric resistance wire. The only difference is that the tread sensors 11A and 12A of the formula are employed, and the other configurations are basically the same as those of the center-of-gravity position measuring apparatus 1 of the first embodiment.
Accordingly, in the center of gravity position measuring apparatus 1A of the second embodiment, the same or similar parts as those of the center of gravity position measuring apparatus 1 of the first embodiment are given the same reference numerals and detailed description thereof is omitted. The following description will focus on differences from the gravity center position measuring apparatus 1 of the first embodiment.

<Description of Detection Principle of Tread Sensor According to Second Embodiment>
A method for detecting the tread interval B of the vehicle 3 by combining the pressure-sensitive rubber and the electric resistance wire will be described.
A similar conventional method is described in JP-A-53-19860-19863.
However, in these conventional methods, it is necessary to incorporate a switch, a diode, an AC power source, or the like in the circuit, or it is necessary to prepare a plurality of electric resistance detectors. In addition, the conventional method is intended to measure the tread width and the tread interval, and the right and left from the joint (the center of the weighing platform) of the two sensors like the tread sensors 11A and 12A according to the present embodiment. It is not possible to know the position of the tread (tread) separately. In addition, in order to detect the tread interval B, it is described that it is necessary to insert a resistor, a switch, a diode, or the like in the center of the conducting wire. The tread sensors 11A and 12A equipped in the center-of-gravity position measuring apparatus 1A of the present embodiment eliminate these drawbacks and are simple circuits, and the distance from the center point to the center of the left and right wheel treads and the tread interval without switching operation. B is obtained.

In the tread sensors 11A and 12A of the pressure sensitive rubber / electric resistance wire type shown in FIGS. 9A and 9B, a ribbon-like conductive wire 62 is placed in the cover rubber 61 embedded in the groove 60 of the road surface GL. The pressure-sensitive conductive rubber 63 and the electric resistance wire 64 are installed in a sandwich state.
When the vehicle 3 such as a truck passes through this upper surface, if the cover rubber 61 is stepped on the left wheel 4a of the first axle 7, for example, only the portion of the tread surface of the wheel 4a is shown in FIG. 9C. The pressure-sensitive conductive rubber 63 is compressed, the upper conductive wire 62 and the lower electric resistance wire 64 are short-circuited, and the pressure-sensitive conductive rubber 63 is energized.
FIG. 10 (a) is a state diagram before stepping on a wheel, FIG. 10 (c) is an equivalent circuit diagram at that time, and FIG. 10 (b) is a state diagram stepping on the wheel. ) Is an equivalent circuit diagram at that time.
In the following description, it is assumed that the voltage is measured by each voltmeter, AD conversion is performed, and various calculations are performed as digital values.

When the state of the equivalent circuit shown in FIG. 10 (c), the current _{I 0} flows associated with voltage _{E d0} to resistor _R 0, _{R d} is the resistance _{R d.} This is obtained by measuring the voltage E ₀ with the voltmeter V _d .
I ₀ = E _d / R _d
Also,
I ₀ = E ₀ / (R ₀ + R _d )
From this, the resistance R ₀ is derived.
R ₀ = E ₀ / I ₀ −R _d
Here, R ₀ is a resistance value corresponding to a half distance from the center line 38 to the outside.

Next, as in the state of the equivalent circuit diagram shown in FIG. _10D , the portion of Rt is short-circuited and becomes conductive, and the current I ₁ flows through the resistor R ₁ + R ₂ + R _d . This is obtained by measuring the voltage E _d1 with the voltmeter V _d .
I ₁ = E _d1 / R _d
Also,
I ₁ = E ₀ / (R ₁ + R ₂ + R ₃ )
From this, the resistance (R ₁ + R ₂ ) is derived.
(R ₁ + R ₂ ) = E ₀ / I ₁ −R _d
(R ₁ + R ₂ ) is a resistance value corresponding to a distance obtained by subtracting the tread width (L _t , R _t ) from half the width dimension (L ₀ , R ₀ ) of the weighing platform 13.

Next, the voltage in the state of the equivalent circuit diagram shown in FIG. 10D is measured to derive a resistance value.
From the voltage E ₁ measured by the voltage V ₁ ,
R ₁ = E ₁ / I ₂
From voltage E ₂ measured by voltmeter V ₂ R ₂ = E ₂ / I ₂
When these are converted into distance,
L ₁ = L ₀ R ₁ / (R ₁ + R ₂ )
L ₂ = L ₀ R ₂ / (R ₁ + R ₂ )
L _t = L ₀ -L ₁ -L ₂
= R ₀ -R ₁ -R ₂
It becomes.

A distance S from the center of the weighing platform 13 to the tread center can be obtained by S = L _t + L _t / 2, and a tread interval B of the vehicle 3 is S (= L _t + L _t / 2) of the opposite tread sensor. It is calculated by adding.
The amount of eccentricity f between the center of the vehicle 3, that is, the center of the tread interval B and the center of the weighing platform 13 is obtained as f = S−B / 2.

It should be noted that if the relationship between the resistance and the distance is corrected and matched in the steady state before the wheels 4a, 5a, 6a; The relationship can be correct.
In the above description, in order to clarify the principle, the resistance value is obtained and then converted into the distance. However, since the resistance values R ₁ and R ₂ are proportional to the voltage values E ₁ and E ₂ , the actual device uses the voltage. You may calculate with the value.
Strictly speaking, the voltmeters V ₁ , V ₂ , V ₃ and the shunt resistor R _d cause an error, but the voltage part has an internal resistance whose resistance value is sufficiently larger than that of the resistance line R 0, and the shunt resistor R _{When d} has a resistance value sufficiently smaller than that of the resistance line R ₀ (for example, R _d / R ₀ = 1/1000), a practical error can be ignored. Further, these may be numerically corrected during the calculation process.
If the pressure-sensitive conductive rubber 63 itself is manufactured with an appropriate resistance, the lower electric resistance wire 64 can be omitted. In addition, although the electric resistance wire 64 is a continuous resistance wire, even if the resistance parts are connected and only the joint portion is brought into contact with the pressure-sensitive conductive rubber 63, the resistance changes stepwise and the accuracy is slightly reduced. It can be adopted if allowed.

[Third Embodiment]
FIG. 11 is an explanatory view of the structure of the center-of-gravity position measuring apparatus according to the third embodiment of the present invention, and is a cross-sectional view taken along line FF in FIGS. -G sectional view (c) is shown respectively.

<Description of Schematic Configuration of Center of Gravity Position Measuring Device According to Third Embodiment>
The center-of-gravity position measuring apparatus 1B shown in FIG. 11 is similar to the center-of-gravity position measuring apparatus 1 of the first embodiment shown in FIG. 1 and includes a first tread sensor 11, a second tread sensor 12, and a weighing platform 13. However, the installation location differs in the vehicle traveling direction.
That is, in the center-of-gravity position measuring apparatus 1 according to the first embodiment, the first tread sensor 11 and the second tread sensor 12 are each embedded in the road surface GL, and the upstream side of the travel route when the vehicle 3 travels forward. Is arranged. On the other hand, in the gravity center position measuring apparatus 1B of the third embodiment, as shown in FIG. 11, the first tread sensor 11 and the second tread sensor 12 are on the weighing platform 13 and the vehicle 3 is It is assembled on the upstream side of the travel route when traveling forward. Note that these tread sensors 11 and 12 may be disposed on the upstream end face of the forward travel path of the vehicle 3 in the weighing platform 13. Alternatively, the first load cell 21 and the third load cell 23 may be arranged on a line connecting the center lines. In these cases, it is possible to cope with changing the timing _{t 1} of the detection signal and the load cell 21 to 24 of the tread sensors 11 and 12.
The configuration other than the above is the same as that of the centroid position measuring apparatus 1 of the first embodiment, and X _G and Y _G can be obtained basically in the same manner as the centroid position measuring apparatus 1 of the first embodiment. The effect of this can be obtained.
Furthermore, according to the center-of-gravity position measuring apparatus of the third embodiment, when installing the tread sensors 11, 12, foundation concrete work for the road surface GL required by the center-of-gravity position measuring apparatus 1 of the first embodiment is required. Therefore, there is an advantage that it is simple and can be retrofitted to a measuring device such as an existing track scale.

[Fourth Embodiment]
FIG. 12 is an explanatory view of the structure of the gravity center position measuring apparatus according to the fourth embodiment of the present invention, and is a cross-sectional view taken along the line HH of FIGS. (A) and (a). A partial enlarged view (c), a simplified diagram (d) of (b) and a mechanical equivalent diagram (e) of (d) for illustrating the balance of force are shown, respectively.
The center-of-gravity position measuring apparatus 1 according to the first embodiment includes a weighing platform 13 that supports a four-point load cell. As a weighing device for weighing a vehicle or the like having a short overall length, the gravity center position measuring device 1 of the first embodiment is sufficient. However, for example, when measuring a long-length vehicle such as a trailer-connected vehicle, a four-point load cell is used. For the support, the members of the weighing platform must be enlarged in terms of strength, which is uneconomical.
In order to solve such a problem, in the center of gravity position measuring apparatus 1C of the fourth embodiment, as shown in FIGS. 12A to 12C, load cells 22 and 25 are further provided at intermediate points of the weighing platform 13C. An economical design is adopted by sharing the supporting load to reduce the weight of the weighing platform 13C. In this case, it is difficult to adjust the height level for sharing the load among all the load cells 21 to 26 with one weighing platform 13C. Its weighing the platform 13C is divided into the divided weighing the platform 13C ₁ at an intermediate position of the vehicle traveling direction and divided weighing the platform 13C ₂ as a solution, sharing the load cell 21 to 26 without affecting the deflection of Nodaihari A load is applied. The center-of-gravity position measuring apparatus 1C according to the fourth embodiment can determine the horizontal center-of-gravity position even in the weighing platform 13C having such a configuration.

As shown in FIG. 12 (c), divided metering weighing platform vehicle traveling direction downstream end of the @ 13 C ₁ has been placed on the vehicle traveling direction upstream side end portion of the split metering the platform @ 13 C _2, these end The overlapping portions of the portions are collectively supported by the second load cell 22 and the fifth load cell 25. Although an example in which the overlapped portions at these ends are in contact with the pinpoints so as to be clarified in terms of dynamics is shown, it is not actually necessary to contact the pinpoints, and the overlapped portions are not connected to the load cells 22 and 25. The following mechanical properties hold even if not directly above.

  Next, mechanical properties in the center-of-gravity position measuring apparatus 1C according to the fourth embodiment will be described below mainly using FIGS. 12 (d) and 12 (e).

Now, assuming that the axial load is a concentrated load, x ₁ > x ₂ > x ₃ > x ₄ , d ≦ x ₃ , x ₄ <a + d, a + d ≦ x ₁ , x ₂ <2a + d. In the following, P ₁ , P ₂ , and P ₃ are redefined and used as follows.
P ₁ : Sum of outputs of first load cell 21 and fourth load cell 24 P ₂ : Sum of outputs of second load cell 22 and fifth load cell 25 P ₃ : Sum of outputs of third load cell 23 and sixth load cell 26

Force P ₂ = P ₂₁ + P ₂₂ acting on the point O ₂
P ₂₁ : The amount that the load on the divided weighing table 13C ₁ contributes to P ₂ P ₂₂ : The amount that the load on the divided weighing table 13C ₂ contributes to P ₂ P ₂₁ = W ₃ x ₃ / a + W ₄ x ₄ / a
P ₂₂ = W ₁ (2a−x ₁ ) / a + W ₂ (2a−x ₂ ) / a
Force acting on the point O ₃ P ₃ = W ₁ (x ₁ −a) / a + W ₂ (x ₂ −a) / a
_{aP 2 + 2aP 3 = {(} 2a-x 1) +2 (x 1 -a)} W 1 + {(2a-x 2) +2 (x 2 -a)} W 2 + x 3 W 3 + x 4 W 4 = x ₁ W ₁ + x ₂ W ₂ + x ₃ W ₃ + x ₄ W ₄
This means that FIG. 12 (d) is mechanically equivalent to FIG. 12 (e).

ここで、ｉは１〜ｎの自然数である Mechanical properties of the above, m pieces load is concentrated on the weighing load platform @ 13 C _1, if there (n-m) pieces in the mounting base @ 13 C _2: indicate that the (m, n is a natural number, m ≦ n) holds for it can. The following is the proof.

Here, i is a natural number of 1 to n.

<Description of how to obtain l ₁ , l ₂ , l ₃ : see FIG. 13>
(1) Formula for calculating the distance between axles The distance between axles l ₁ and l ₂ is the time detected by the first tread sensor 11 or the second tread sensor 12 being stepped on the i-th wheel, and each time t = t _i measured value _P 2 (t) of the load cell load _in, is calculated using the _P 3 (t) and _{W i.}

l ₁ of the calculation formula:
At t = t ₂ (see FIG. 13B), the balance equation of moments with the load cells 21 and 23 as fulcrums is expressed by the following equation (21).
aP ₂ (t) + 2aP ₃ (t) −x ₁ W ₁ = 0 (21)
Since x ₁ = l ₁ −c, l ₁ is obtained from the following equation (22).
l ₁ = (aP ₂ (t) + 2aP ₃ (t)) / W ₁ + c (22)

Formula for calculating l ₂ :
At t = t ₃ (see FIG. 13C), the balance equation of moments with the load cells 21 and 23 as fulcrums is expressed by the following equation (23).
aP ₂ (t) + 2aP ₃ (t) −x ₁ W ₁ −x ₂ W ₂ = 0 (23)
x ₁ = l ₁ + l ₂ −c,
Since x ₂ = x ₁ −l ₁ = l ₂ −c, l ₂ is obtained from the following equation (24).
l ₂ = (aP ₂ (t) + 2aP ₃ (t) −l ₁ W ₁ ) / (W ₁ + W ₂ ) + c
... (24)

the calculation formula of l _3:
At t = t ₄ (see FIG. 13 (d)), the moment balance equation with the load cells 21 and 23 as fulcrums is expressed by the following equation (25).
_{aP 2 (t) + 2aP 3} (t) -x 1 W 1 -x 2 W 2 -x 3 W 3 = 0
... (25)
x ₁ = l ₁ + l ₂ + l ₃ −c,
x ₂ = x ₁ −l ₁ = l ₂ + l ₃ −c,
Since x ₃ = x ₂ −l ₂ = l ₃ −c, l ₃ is obtained from the following equation (26).

ここで、Ｗ_０＝０、τ_ｉ＜ｔ＜τ_ｉ＋１、ｉ＝１，２，３およびｔ＞τ_ｉ，ｉ＝４である。 (2) Measurement of axial load As shown in FIG. 14, the axial load is calculated as P (t) = P ₁ (t) + P ₂ (t) + P ₃ (t) as in the first embodiment. It is obtained by the following equation (27) from the step-like change with time.

Here, W ₀ = 0, τ _i <t <τ _{i + 1} , i = ₁ , 2, 3 and t> τ _i , i = 4.

<Determination of the description of _{X G>}
The calculation method described in the first embodiment can also be applied here.
Assuming that the first wheel 7 of the four-axis vehicle 3C is the origin O, a general formula of the moment balance around the origin O is expressed by the following equation (28). Here, _XG is negative.
_XG W + W ₂ l ₁ + W ₃ (l ₁ + l ₂ ) +... + W _n (l ₁ + l ₂ +... + L _n-1 ) = 0
... (28)
From the above equation (28), X _G is obtained by the following equation (29).
X _G = − {W ₂ l ₁ + W ₃ (l ₁ + l ₂ ) +... + W _n (l ₁ + l ₂ +... + L _n−1 )} / W
... (29)
here,
W = W ₁ + W ₂ +... + W _n
W _i = axial weight (i = 1, 2,..., N)
n: Number of axles l _j : Distance between shafts.
Then, in the formula (29), at the n = 4, X-direction center-of-gravity position _{X G} of the vehicle 3C 4-axis shown in FIG. 12-13 are determined.

<Description of the method of obtaining the _{Y G>}
It can be obtained in the same manner as in the case of the four-point load cell support described above.
In FIG. 12, when the output of each load cell 21-26 is adjusted to zero in the state where there is no load (vehicle 3C) on the weighing platform 13C, and the output sensitivity of each load cell 21-26 is equal, the coordinates of the vehicle 3C The center-of-gravity position y _G in the system o-xy can be obtained by the following equation (30) using the outputs P ₁ , P ₂ ,..., P ₆ of the load cells 21 to 26.
y _G = (P ₁ + P ₂ + P ₃ ) b / W−b / 2 (30)
However, W = P ₁ + P ₂ + P ₃ + P ₄ + P ₅ + P ₆ .
W may be measured after all the axles have been placed on the weighing platform 13C. The calculation performed using each measurement value does not need to be performed in real time, and may be performed after being stored in the memory 48 and subjected to waveform processing at a necessary timing.
Then, you can determine the centroid position _{Y G} in the Y direction of the vehicle 3C using the equation (16) from the f obtained from the and _{y G} obtained from the formula (29) (15).

  In each of the above embodiments, the deviation f between the center X axis of the vehicles 3 and 3C and the center x axis of the weighing platforms 13 and 13C can be calculated for each axle. A thing may be employ | adopted and an average value may be taken and employ | adopted.

<Description of Correspondence between Terms with the Present Invention>
The configuration including the first tread sensor 11 and the second tread sensor 12 corresponds to the “vehicle width direction relative position detection means” and the “wheel predetermined position passage detection means” of the present invention.
The vehicle width direction center of gravity position calculation unit 50 corresponds to “vehicle width direction center of gravity position calculation means” of the present invention.
The vehicle full length direction gravity center position calculation unit 50 corresponds to the “vehicle full length direction gravity center position calculation unit” of the present invention.

  As mentioned above, although the gravity center position measuring apparatus of the present invention has been described based on a plurality of embodiments, the present invention is not limited to the configurations described in the above embodiments, and the configurations described in the embodiments are appropriately combined. The configuration can be changed as appropriate without departing from the spirit of the invention.

  The center-of-gravity position measuring apparatus of the present invention has a characteristic that it can measure the horizontal center-of-gravity position of a vehicle with a simple and inexpensive configuration, and therefore, it is used for providing effective data that contributes to prevention of vehicle rollover. Can be suitably used.

DESCRIPTION OF SYMBOLS 1 Center-of-gravity position measuring apparatus 11 1st tread sensor 12 2nd tread sensor 13 Weighing base 21 1st load cell 22 2nd load cell 23 3rd load cell 24 4th load cell 50 Vehicle width direction gravity center position calculating part 51 Vehicle full length direction gravity center position calculation Part

Claims (5)

A center-of-gravity position measuring device that measures a horizontal center-of-gravity position of a vehicle,
(A) a weighing platform on which all the left and right wheels of the vehicle can be mounted;
(B) a plurality of load cells arranged at predetermined intervals in the width direction and the total length direction of the vehicle and supporting the weighing platform;
(C) vehicle width direction relative position detection means for detecting a relative position in the width direction of the vehicle with respect to the weighing platform when the vehicle is placed on the weighing platform;
(D) a wheel predetermined position passage detecting means for detecting that the vehicle wheel has passed a predetermined position when the vehicle is mounted on the weighing platform;
(E) a vehicle width direction center-of-gravity position calculating unit that calculates a center of gravity position in the vehicle width direction based on load signals from the plurality of load cells and a detection signal from the vehicle width direction relative position detecting unit;
(F) Vehicle length direction center-of-gravity position calculation means for calculating the position of the center of gravity of the vehicle in the full length direction based on load signals from the plurality of load cells and detection signals from the wheel predetermined position passage detection means. The center of gravity position measuring device characterized by.   The vehicle width direction relative position detecting means includes a rod-like member arranged horizontally in the vehicle width direction so that each wheel of the vehicle can step on and a strain gauge attached to both ends of the rod-like member. The center-of-gravity position measuring device according to claim 1, comprising:   The vehicle width direction relative position detection means includes a conductive rubber extending horizontally in the vehicle width direction so that each wheel of the vehicle can be stepped on and the conductive rubber on each wheel of the vehicle. The center-of-gravity position measuring device according to claim 1, comprising a deformed portion when stepped on and an electric resistance wire arranged so as to be able to come into contact.   The center-of-gravity position measuring device according to any one of claims 1 to 3, wherein the vehicle width direction relative position detecting means is assembled to the weighing platform.   The center-of-gravity position measuring device according to any one of claims 1 to 4, wherein the weighing platform is configured by combining a plurality of divided weighing platforms arranged along the traveling direction of the vehicle.

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