JP2014174019A - Device and method to measure gravity center of suspended load - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device to measure a gravity center of a suspended load which can easily and speedily measure a position of the gravity center of a container and is highly practical.SOLUTION: A device to measure a gravity center of a suspended load 10 comprises: a plurality of engaging sections which are engaged with a container 50; a load sensor 18 which detects loads acting on the plurality of engaging sections; a spreader 12 which has acceleration sensors 14 which detect acceleration applied to a suspended load and angular acceleration as needed and an inclination sensor 16; and calculation means 20 which calculates a position of a gravity center of the container 50 in a vertical direction from measured loads by the load sensor 18 and the acceleration in a moving direction when moving the container 50 with no angular acceleration detected on the basis of an inclination angle around a horizontal axis perpendicular to the moving direction measured by the inclination sensor 16.

Description

  The present invention relates to a technique related to lifting and transfer of heavy objects and the like, and more particularly to a technique for measuring the center of gravity of a heavy object and the like related to lifting and transfer.

  Information on the weight and contents of containers unloaded at ports and the like is provided. On the other hand, since the container bunning (packing) state is not questioned during transportation, there are many cases where the position of the center of gravity is biased or the position of the center of gravity is high and unstable. Due to this situation, in recent years, there have been frequent rollover accidents of trailers loaded with unloaded containers.

  For this reason, letting the trailer driver know at least what the center of gravity (in particular, the center of gravity in the height direction) of the loaded container is in a state that helps to prevent a rollover accident. It is considered.

  Under such a background, techniques disclosed in Patent Document 1 and Patent Document 2 have been proposed as techniques for measuring the position of the center of gravity of a load such as a container. The technique disclosed in Patent Document 1 calculates the position of the center of gravity based on the weight balance and the shake when the vehicle body is swung by placing the trailer loaded with the container on the measuring device as it is. Is.

  Moreover, the technique currently disclosed by patent document 2 is a technique of calculating the gravity center position of a container, when unloading to a trailer via a crane. As a specific configuration, in the technique disclosed in Patent Document 2, it is assumed that the container is lifted by four ropes (wires) and transferred. Each wire is provided with a load sensor and a tilt sensor. Then, the center of gravity of the container in the horizontal direction is calculated based on the balance of the weight applied to each wire when the container is lifted in the vertical direction. Also, when the container is moved horizontally, the center of gravity in the vertical direction of the container is obtained based on the inclination angle of the wire caused by inertia, the weight of the container, and the balance in the horizontal direction of the container.

JP 2012-2558 A JP 2012-37469 A

According to the technique disclosed in the above patent document, the center of gravity position of the container can surely be obtained, and the driver of the trailer loading the container can be alerted.
However, in the technique disclosed in Patent Document 1, after loading a container on a trailer, it is necessary to move the trailer to a separately provided measuring device and perform measurement separately. For this reason, it is considered difficult to measure all trailers loaded with containers as well as time loss. Moreover, since the measuring device is large and expensive, there are problems of installation space and cost.

In addition, the technique disclosed in Patent Document 2 is required to detect the inclination of the wire. For this reason, the operation | work which fixes four wires individually with respect to all the containers unloaded is required. Therefore, when there are many containers to be unloaded, human labor becomes enormous.
As described above, any of the techniques disclosed heretofore are theoretically possible, but problems arise in practical use.

  Therefore, an object of the present invention is to provide a suspended barycentric gravity measuring apparatus and method that can easily and quickly measure the barycentric position of a container and have high practicality.

In order to achieve the above object, an apparatus for measuring a center of gravity of a suspended load according to the present invention includes a plurality of engaging portions that are engaged with the suspended load, a load sensor that detects a load applied to the plurality of engaging portions, A physical quantity sensor for detecting acceleration or angular acceleration applied to the suspended load, and a horizontal axis orthogonal to the moving direction measured by the physical quantity sensor when the suspended load is moved. And calculating means for calculating a vertical center of gravity position of the suspended load based on a load measured by the load sensor and an acceleration in a moving direction when the angular acceleration is zero.
The center of gravity measuring device for a suspended load according to the present invention for achieving the above object includes a plurality of engaging portions that are engaged with the suspended load, and a load sensor that detects a load applied to the plurality of the engaging portions. , A physical quantity sensor for detecting an acceleration applied to the suspended load, and when the suspended load is suppressed when the suspended load is moved, And calculating means for calculating a vertical center of gravity position of the suspended load based on the measured load and the acceleration in the moving direction.

  In the suspended load center-of-gravity measurement apparatus having the above characteristics, the suspended load lifting means includes a plurality of physical quantity sensors, and at least one physical quantity sensor is a sensor that detects an inclination of the suspended load lifting means, The calculating means may use the inclination angle of the suspended load lifting means as a correction value for the measurement value by the load sensor when calculating the position of the center of gravity in the vertical direction.

  By having such a feature, it is possible to accurately calculate the center-of-gravity position in the vertical direction in the container even when the suspended container is inclined.

In the suspended load center-of-gravity measurement apparatus having the above characteristics, the suspended load lifting means includes a plurality of physical quantity sensors, and at least one physical quantity sensor detects a vertical acceleration of the suspended load lifting means. And the said calculating means can also utilize the vertical direction acceleration of the said lifting means for lifting as a correction value with respect to the measured value by the said load sensor, when calculating the said gravity center position of the perpendicular direction.
With such a feature, it is possible to accurately calculate the vertical center of gravity of the container even when the container is moved horizontally while being raised or lowered.

In the suspended load center-of-gravity measurement apparatus having the above characteristics, the calculation means may also calculate the horizontal center-of-gravity position of the suspended load based on the measured load by the load sensor.
With such a feature, the center of gravity position of the container can be obtained three-dimensionally.

Further, in the suspended load center-of-gravity measuring apparatus having the above characteristics, the vertical gravity center position of the suspended load or the vertical gravity center position and the horizontal gravity center position of the suspended load calculated by the calculation unit can be visually recognized. It is advisable to provide display means for displaying on the screen.
By having such a feature, it is possible to easily grasp the position of the center of gravity of the container by referring to the display means.

  The center of gravity measurement method for a suspended load according to the present invention for achieving the above object is the above-described method that occurs around a horizontal axis perpendicular to the moving direction when the suspended load is lifted and moved by being locked by a plurality of suspension points. When the angular acceleration of the suspended load is zero, the vertical gravity center position of the suspended load is calculated based on the load applied to the plurality of hanging points and the acceleration in the moving direction.

In the suspended load center-of-gravity measurement method having the above characteristics, the tilt angle of the suspended load is used as a correction value for the load applied to the suspension point when calculating the vertical gravity center position of the suspended load. Good.
By having such a feature, it is possible to accurately calculate the center-of-gravity position in the vertical direction in the container even when the suspended container is inclined.

In the suspended load center-of-gravity measurement method having the above characteristics, when the vertical center of gravity position of the suspended load is calculated, the load applied to the suspension point by the vertical acceleration when the suspended load is moved is calculated. It can also be used as a correction value.
With such a feature, it is possible to accurately calculate the vertical center of gravity of the container even when the container is moved horizontally while being raised or lowered.

Furthermore, in the suspended load center-of-gravity measurement method having the above features, the horizontal center-of-gravity position of the suspended load may be calculated based on the weight balance of the load applied to the suspension point.
With such a feature, the center of gravity position of the container can be obtained three-dimensionally.

  According to the suspended barycentric gravity measuring apparatus and method having the above-described features, the barycentric position of the container can be measured easily and quickly. Therefore, practicality can be improved as compared with the conventional case, such as 100% inspection of containers is possible.

FIG. 1 is a diagram showing an overall configuration of the suspended load center-of-gravity measurement device of the present invention. FIG. 2 is a diagram illustrating the weight applied to a container that is stationary in a lifted state. FIG. 3 is a diagram illustrating a change in force generated when the suspended container is moved. FIG. 4 is a diagram illustrating a change in force generated when the container is moved in a state where the lifted container is inclined.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a suspended barycenter measurement apparatus and method according to the present invention will be described in detail with reference to the drawings. In the embodiment described below, a container is cited as a suspended load, and a spreader is cited as a suspended load lifting means.However, as long as the present invention is applicable, the suspended load is not limited to a container, Needless to say, the suspended load lifting means is not limited to a spreader.

  FIG. 1 is a diagram showing an overall configuration of the suspended load center-of-gravity measurement device of the present invention. FIG. 2 is a diagram showing the weight applied to the container that is stationary in the lifted state. FIG. 3 is a diagram illustrating a change in force generated when the suspended container is moved. FIG. 4 is a diagram illustrating a change in force generated when the container is moved in a state where the lifted container is inclined.

  The center-of-gravity measurement device for suspended loads according to the present embodiment (hereinafter simply referred to as the center-of-gravity measurement device 10) is configured based on a spreader 12 as a suspended load lifting means and a calculation means 20, and includes a display means 30 and an input means. (Not shown) etc. are attached.

  The spreader 12 is a hanging tool disposed on the container 50. In the example shown in FIG. 1, hanging metal fittings as locking portions that are locked to locking holes formed in the container are arranged at the four corners on the lower surface side. By disposing the spreader 12 on the upper part of the container 50 and rotating and locking the suspension fitting inserted into the engagement hole (suspension hole), the container can be lifted via the spreader. Load sensors 18a, 18b, 18c, and 18d are disposed on the respective suspension brackets. The load sensor 18 (18a to 18d) may be configured to measure a load applied in the axial direction of the hanging bracket.

  Further, the spreader 12 is provided with an acceleration sensor 14 as a physical quantity sensor and an inclination sensor 16. The type of the acceleration sensor 14 is not particularly limited, but may be any sensor that can measure at least the acceleration in the moving direction when moving the container 50 and the acceleration when moving up and down. The tilt sensor 16 may be any sensor that can measure the tilt angle θ around the horizontal axis (specifically, around the center of gravity) orthogonal to the moving direction. The measured inclination angle θ can be obtained by differentiating the angular velocity once by differentiating the angular velocity twice and by obtaining the angular acceleration by differentiating twice. Therefore, by arranging the acceleration sensor 14 and the inclination sensor 16 on the spreader 12, the horizontal acceleration of the container 50 locked to the spreader 12 and the angular acceleration around the horizontal axis perpendicular to the traveling direction can be obtained. .

  In the present embodiment, a plurality (three) of acceleration sensors 14 are arranged at intervals along the long side direction of the spreader 12. Here, the respective acceleration sensors 14 are arranged so that all of them are not aligned on a straight line. By disposing the acceleration sensors 14 at three or more points that are separated from each other, a plane connecting the points is formed, and can be regarded as an integral object (rigid body) with the spreader 12. As specific arrangement forms of the acceleration sensor 14 in the embodiment, there are an acceleration sensor 14 arranged at the central portion and an acceleration sensor 14 arranged at the both end portions in the length direction of the container 50. It arrange | positions so that it may mutually be located in the both ends of the width direction of the container 50. FIG.

The spreader 12 having such a basic configuration is moved up and down and horizontally moved via a crane (not shown).
The computing means 20 plays a role of calculating the vertical center of gravity position and the horizontal center of gravity position of the container 50 based on the data detected by the load sensor 18, the acceleration sensor 14, and the tilt sensor 16. The calculation means 20 is configured to be able to receive measurement data from the load sensor 18, the acceleration sensor 14, and the tilt sensor 16 by means of wired or wireless or both. Therefore, when the measurement data is received wirelessly, the spreader 12 is accompanied by a transmission means (not shown), and the calculation means 20 is accompanied by a reception means (not shown).

  The calculation means 20 includes at least an input / output control unit 22, an auxiliary storage unit 24, a main storage unit 26, a calculation unit 28, and the like. The input / output control unit 22 is a connection / conversion unit related to data input / output such as an interface. The auxiliary storage unit 24 is a storage unit such as a hard disk or a flash memory. The main storage unit 26 is a memory that contributes to processing by the calculation unit 28. The calculation unit 28 is a CPU. The input / output control unit 22, the auxiliary storage unit 24, the main storage unit 26, and the calculation unit 28 are connected to each other via a bus so as to be able to exchange data.

  In the arithmetic means 20 having such a basic configuration, data detected by various sensors is input via the input / output control unit 22 and recorded in the auxiliary storage unit 24. The auxiliary storage unit 24 stores a calculation program necessary for calculating the vertical gravity center position and the horizontal gravity center position in the container 50, and the calculation unit 28 reads the program into the main storage unit 26. The operation is executed. The calculation is performed by reading the measurement data recorded in the auxiliary storage unit 24 in accordance with the execution program and assigning it to the program as input data to the execution program.

  The vertical center-of-gravity position and the horizontal center-of-gravity position of the container 50 calculated by the calculation are primarily recorded in the auxiliary storage unit 24 and output via the input / output control unit 22 to be displayed on the display unit 30. Is done.

The display means 30 is a monitor that displays the vertical gravity center position and horizontal gravity center position of the container 50 calculated by the calculation means 20 so that the operator or the driver of the trailer that loads the container 50 can visually recognize it. Etc. Note that the display of the center of gravity position via the display means 30 may be numerical or image-like.
The input means may be any means for inputting information necessary for measuring the position of the center of gravity.

Next, a method of calculating the center of gravity using the center of gravity measuring apparatus 10 having such a configuration will be described. As shown in FIG. 2, loads F ₀ 11, F ₀ 12, F ₀ 21, F ₀ 22 (unit: kgf) measured by the load sensor 18 in a state where the container 50 suspended through the spreader 12 is stationary. ) And the mass M of the container 12 can be expressed as Equation 1. In Equation 1, g is gravitational acceleration.

... (Formula 1)

When the container 50 lifted in this way is moved in the direction of the arrow V at an acceleration a (m / s ² ), a force (moment) to rotate around the center of gravity, which is a horizontal axis orthogonal to the traveling direction, is generated. work. For this reason, the load increases and decreases before and after the container 12 with the center of gravity position as the base point (the traveling direction is front) (see FIG. 3).

The container 50 is in a stationary state in the vertical direction, and no rotational motion occurs around the center of gravity. Therefore, the total value of the suspension loads at the four suspension points is the same as the total value of the suspension loads at rest. Here, if the increase / decrease in load measured at each suspension point (load sensor 18) is expressed as ΔF11, ΔF12, ΔF21, ΔF22 (unit is kgf), the total increase / decrease value of the load at each suspension point is 0. Equation 2 is established.

... (Formula 2)

Here, the total load increase / decrease occurring in the measured values of the load sensors 18a, 18b located on the front side in the moving direction of the container 50 is calculated.

... (Formula 3)
In this case, the total load increase / decrease occurring in the measurement values of the load sensors 18c and 18d located on the rear side in the moving direction of the container 50 is calculated from the relationship of force balance.

... (Formula 4)
It can be expressed as.
Here, although not shown in FIG. 3, four shear points in the container 50 are actually subjected to a shear load in addition to the vertical load. However, the shear load is an unknown value because accurate measurement is difficult.
Therefore, the balance of moments around the upper left point of the container 50 in FIG. 3 is considered here. Then, Equation 5 can be derived from the suspension formula of the inertia force acting on the center of gravity G, the moment of gravity, and the moment of “F ₀ 21 + F ₀ 22 + ΔF” acting on the upper right point of the container 50.

... (Formula 5)
Then, Formula 6 can be obtained from a static moment suspension formula with the acceleration a being zero.

... (Formula 6)
Therefore, the relationship of Equation 7 can be obtained from the relationship of Equation 5 and Equation 6.

... (Formula 7)

When Expression 7 is moved with respect to the vertical distance H (m) from the upper part of the container 50, Expression 8 can be obtained.

... (Formula 8)

From the above, the mass M (kg) of the container 50, the acceleration a (m / s ² ) in the moving direction, the load change ΔF (kgf) generated at the suspension point during the movement, and the length L (m) of the container 50 Based on this, the center-of-gravity position (vertical distance H (m)) in the vertical direction in the container 50 can be obtained. As the container 50 moves, the container 50 may rotate (swing) around a horizontal axis (horizontal axis passing through the center of gravity) orthogonal to the traveling direction. The effect will be added. Further, when the rotational motion has an angular acceleration, the value of ΔF is also affected. For this reason, when obtaining the acceleration a and the load change ΔF, the acceleration is calculated using data in a state where the angular acceleration obtained by differentiating the measurement value measured by the tilt sensor twice is zero.

  Even when the rotational angular acceleration is zero, when the rotational angular velocity is not zero, the acceleration measured by the acceleration sensor is added to the acceleration due to the rotational motion. The rotation center of the container 50 is obtained from the angular velocity, corrected by subtracting the influence of the acceleration due to the rotation at each sensor installation position due to the rotational motion, and the acceleration a in the traveling direction is obtained. If the rotational angular acceleration is zero, the value of ΔF is not affected even when the rotational angular velocity is not zero.

  Therefore, when calculating the vertical center-of-gravity position in the container 50, data that changes with the movement of the container 50 is sequentially recorded in time series, and the angular acceleration generated by the swing around the center-of-gravity axis becomes zero. The various data at the time of selection is selected and calculated.

  Thus, the vertical center of gravity of the container 50 is calculated simply and quickly by calculating the vertical center of gravity of the container 50 based on the data obtained when the container 50 is unloaded via the spreader 12. You can know the position. Therefore, it is possible to tell the trailer driver where the center of gravity is in the height direction before or when the container 50 to be unloaded is loaded on the trailer.

  Further, according to the present invention, unlike the technique disclosed in Patent Document 1, since the wire inclination angle is not one of the measurement values, the container 50 can be quickly transferred via the spreader 12 as a rigid body. The position of the center of gravity can be calculated. Furthermore, a large and expensive device as disclosed in Patent Document 2 is not required, and the total inspection of the containers 50 is facilitated. Therefore, it can be said that the center-of-gravity measurement method using the center-of-gravity measurement apparatus 10 according to the present embodiment is more practical than the conventional one.

Moreover, according to the center-of-gravity measurement method according to the present embodiment, it is possible to obtain a balance of measurement values (load balance) in each load sensor 18. Therefore, when the distance in the width direction of the container 50 is W (m) and the distance in the length direction is L (m), the ratio of the horizontal distance from the center of gravity position to the width direction end of the container 50 is

... (Formula 9)
Can be shown. Moreover, the ratio of the horizontal distance from the center of gravity position to the lengthwise end of the container 50 is

(Equation 10)
Can be shown. Therefore, when the distances from the center of gravity to the ends in the width direction and the length direction are A, B, C, and D as shown in FIG.

... (Formula 11)
Can be calculated as As described above, according to the center-of-gravity measurement method according to the present invention, the center-of-gravity position in the horizontal direction can be calculated in addition to the center-of-gravity position in the vertical direction in the container 50.

Next, as shown in FIG. 4, calculation of the vertical gravity center position and the horizontal gravity center position when the tilt angle θ is generated in the container 50 at the time of lifting will be described.
In the case of such a configuration, the acceleration a (m / s ² ) measured by the acceleration sensor 14 is detected in a state where the detection direction is inclined by θ, and thus is smaller than the acceleration in the actual movement direction. Detected as Therefore, when the detected value is a (m / s ² ), the acceleration a ′ in the horizontal direction (moving direction) can be obtained by Expression 12 using the inclination angle θ as a correction value.

... (Formula 12)

Here, when the loads measured by the respective load sensors 18 at the time of stationary at an inclination angle θ are F ₀ 11 ′, F ₀ 12 ′, F ₀ 21 ′, and F ₀ 22 ′, acceleration a in the moving direction The increase or decrease in the load that occurs before and after the container 50 when ′ is given is denoted by ΔF ′. Then, Equation 13 can be derived from the moment balance at this time.

... (Formula 13)

Therefore, the vertical center of gravity position H in the container 50 can be calculated by Equation 14.

... (Formula 14)

In the present embodiment, the loads F ₀ 11 ′, F ₀ 12 ′, F ₀ 21 ′, and F ₀ 22 ′ measured by the load sensors 18 are tensile loads in the direction inclined by the angle θ. Therefore, the load applied in the vertical direction can be obtained by dividing the load measured at each suspension point by cos θ. Therefore, M in Equation 13 is calculated by Equation 15 unlike M in Equation 7.

... (Formula 15)

Further, when cos θ is used as the load correction value with the use of Equation 11, the distances A, B, C, and D from the horizontal center of gravity position to each side can be calculated by Equation 16.

... (Formula 16)

  In the above description, an example has been described in which the vertical center-of-gravity position of the container 50 is calculated based on the load fluctuation when the container 50 is horizontally moved from the stationary state. However, the transfer of the container 50 does not necessarily perform the ascending, horizontally moving, and descending operations individually. For example, there is a case where a lateral movement operation is performed simultaneously with an ascending operation or a descending operation (oblique movement). This is because the time required for the transfer (unloading) of the container 50 can be shortened by performing the transfer using such a flow line.

When the container 50 moves horizontally (moves laterally) while moving up or down at an acceleration b (m / s2), the mass M of the container 50 is (g ± b) / g during rising or lowering. Will be doubled. Therefore, by using this value ((g ± b) / g) as a correction value and dividing M in Formula 8, Formula 11, Formula 14, and Formula 16 by this value, the mass when there is no rise or fall is obtained. It can be converted.
In addition, when the tilt angle θ is generated in the container 50 at the time of lifting, the acceleration a (m / s ² ) measured by the acceleration sensor 14 is a value that is reduced or added by b × sin θ. These values can be corrected by adding or subtracting this value to the value a in Equations 12, 13, and 14.
In this way, it is possible to calculate the vertical gravity center position and the horizontal gravity center position of the moving container 50.

  In the embodiment described above, the inclination sensor 16 is used to detect the angular acceleration of the container 50, and the measurement value is differentiated twice. However, instead of the tilt sensor 16, an angular velocity sensor, an angular acceleration sensor, or the like as a physical quantity sensor may be used. This is because the value detected by the angular velocity sensor can be converted into angular acceleration by differentiating once.

In carrying out the method according to the present invention, the moving speed and rotational speed of the container 50 are detected by detecting the position and orientation of the container 50, and the acceleration and angular acceleration are calculated based on these values. Also good.
Furthermore, some container cranes are provided with a steadying device that prevents the container 50 from shaking. If the influence of the shaking of the container 50 can be ignored, the detection of the rotational angular acceleration is omitted and the position of the center of gravity is omitted. It is also possible to use an apparatus and a method for performing the measurement.

DESCRIPTION OF SYMBOLS 10 ......... Center-of-gravity measuring device, 12 ......... Spreader, 14 ......... Acceleration sensor, 16 ......... Tilt sensor, 18 (18a to 18d) ......... Load sensor, 20 ......... Calculation means, 22 ... ... Input / output control unit 24... Auxiliary storage unit 26... Main storage unit 28... Calculation unit 30.

Claims (10)

A plurality of engaging portions that are engaged with the suspended load; a load sensor that detects a load applied to the plurality of engaging portions; and a physical quantity sensor that detects acceleration and angular acceleration applied to the suspended load. Hanging load lifting means,
Based on the measured load by the load sensor and the acceleration in the moving direction when the angular acceleration around the horizontal axis perpendicular to the moving direction measured by the physical quantity sensor is zero when moving the suspended load, the suspended load is Calculating means for calculating the center of gravity position in the vertical direction at
An apparatus for measuring the center of gravity of a suspended load, characterized by comprising: Suspended load comprising: a plurality of engaging portions that are engaged with the suspended load; a load sensor that detects loads applied to the plurality of engaging portions; and a physical quantity sensor that detects acceleration applied to the suspended load. Lifting means;
An arithmetic operation for calculating a vertical center of gravity position of the suspended load based on a load measured by the load sensor and an acceleration in the moving direction when the suspended load is suppressed when moving the suspended load. Means,
An apparatus for measuring the center of gravity of a suspended load, characterized by comprising: The suspended load lifting means includes a plurality of physical quantity sensors, and at least one physical quantity sensor is a sensor that detects an inclination of the suspended load lifting means,
3. The calculation means according to claim 1, wherein when calculating the vertical center of gravity position, the inclination angle of the suspended load lifting means is used as a correction value for a measurement value by the load sensor. The center-of-gravity measurement device for suspended loads as described. The suspended load lifting means includes a plurality of physical quantity sensors, and at least one physical quantity sensor is a sensor that detects acceleration in the vertical direction of the suspended load lifting means,
The said calculating means uses the vertical direction acceleration of the said hanging load lifting means as a correction value with respect to the measured value by the said load sensor, when calculating the gravity center position of the said vertical direction. The center-of-gravity measurement device for a suspended load according to any one of the above.   The center of gravity measurement of a suspended load according to any one of claims 1 to 4, wherein the calculation means also calculates a horizontal center of gravity position of the suspended load based on a measured load by the load sensor. apparatus.   The display device displays the vertical gravity center position of the suspended load calculated by the calculation means, or the vertical gravity center position and horizontal gravity center position of the suspended load so as to be visible. The center-of-gravity measurement device for a suspended load according to any one of 1 to 5.   When the suspended load is lifted and moved by being locked by a plurality of suspension points, the load applied to the plurality of suspension points when the angular acceleration of the suspended load generated around the horizontal axis perpendicular to the moving direction is zero, and A method for measuring the center of gravity of a suspended load, wherein a vertical center of gravity position of the suspended load is calculated based on an acceleration in a moving direction.   8. The suspended load according to claim 7, wherein when the vertical gravity center position of the suspended load is calculated, an inclination angle of the suspended load is used as a correction value of a load applied to the suspension point. 9. Center of gravity measurement method.   The vertical acceleration when the suspended load is moved is used as a correction value of a load applied to the hanging point when calculating the center of gravity position of the suspended load in the vertical direction. Or the center-of-gravity measurement method of the suspended load of 8.   The center-of-gravity measurement of a suspended load according to any one of claims 7 to 9, wherein a horizontal center-of-gravity position of the suspended load is also calculated based on a weight balance of a load applied to the suspension point. Method.