WO2014054318A1 - Gravity center position detection device, gravity center position detection method, and program - Google Patents

Abstract

This gravity center position detection device (100) obtains the position of the center of gravity of a load suspended by a crane from a rope support position using a rope. The gravity center position detection device (100) is provided with: a distance calculation unit (103) for calculating the distance between the rope support position and the center of gravity of the suspended load; and a gravity center height calculation unit (105) for calculating the height, within the suspended load, of the center of gravity of the suspended load by subtracting the distance between the rope support position and the upper surface of the suspended load from the distance between the rope support position and the center of gravity of the suspended load.

Description

Center of gravity position detection apparatus, center of gravity position detection method, and program

The present invention relates to a gravity center position detection device, a gravity center position detection method, and a program.
This application claims priority based on Japanese Patent Application No. 2012-221474 filed in Japan on October 3, 2012, the contents of which are incorporated herein by reference.

It is useful to detect the position of the center of gravity in the height direction (vertical direction) of the container in order to prevent the container transportation vehicle from breaking the balance during the transportation of the container. That is, when the gravity center position of the container is high, the balance is easily lost in comparison with the case where the gravity center position is low. Therefore, when the center of gravity of the container is high, it is conceivable to take measures such as rearranging the cargo of the container to lower the position of the center of gravity or alerting the driver of the container transport vehicle.

Here, in relation to the detection of the center of gravity position of the container, the container center of gravity position detection device described in Patent Document 1 includes a radiation source, a detector disposed with a container entry space between the radiation source, and a detector. And an arithmetic device that performs arithmetic processing based on the output of the above. The arithmetic unit obtains the intensity distribution of the radiation that has reached the detector from the radiation source in a state where the container has entered the container entry space, and calculates the density distribution of the container based on the intensity distribution of the radiation. Based on this, the position of the center of gravity of the container is specified.
Thereby, in the container gravity center position detection apparatus of patent document 1, the gravity center position of a container can be specified easily, without opening a container. In particular, in the container center-of-gravity position detection device described in Patent Document 1, the center-of-gravity position can be specified also in the height direction of the container.

JP 2006-9803 A

Depending on the type of luggage loaded in the container, there may be a relatively small amount of radiation transmission even with relatively light luggage, or a relatively large amount of radiation transmission even with relatively heavy luggage. In such a case, when the density distribution of the container is calculated from the intensity distribution of the radiation that has passed through the container, an error may be included in the obtained density distribution. Therefore, an error may be included in the center of gravity position in the height direction of the container calculated from the density distribution. The center of gravity in the height direction can be obtained more accurately even when a relatively light load with a relatively small amount of radiation transmission or a relatively heavy load with a relatively large amount of radiation transmission is loaded in the container. Is preferred.

The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a center-of-gravity position detection device, a center-of-gravity position detection method, and a program that can more accurately determine the center-of-gravity position in the height direction. There is.

The present invention has been made to solve the above-described problems, and a gravity center position detection device according to an aspect of the present invention is a gravity center position detection device that obtains the gravity center position of a suspended load suspended by a rope from a rope support position by a crane. The distance between the support position and the center of gravity of the suspended load is calculated from the distance between the rope support position and the center of gravity of the suspended load. A suspended load center-of-gravity height calculation unit that subtracts the distance from the upper surface to obtain the height of the center of gravity of the suspended load in the suspended load.

Further, the center-of-gravity position detection device according to another aspect of the present invention is the above-described center-of-gravity position detection device, wherein the support position center-of-gravity distance calculation unit is in a state in which the suspended load is shaken. The distance between the rope support position and the center of gravity of the suspended load is determined based on the amount of swing of the suspended load and the acceleration of the suspended load.

Further, the center-of-gravity position detection device according to yet another aspect of the present invention is the above-described center-of-gravity position detection device, wherein the support position center-of-gravity distance calculation unit is in a state in which the suspended load is shaken. A distance between the rope support position and the center of gravity of the suspended load is obtained based on the swing period of the suspended load.

The center-of-gravity position detection device according to yet another aspect of the present invention is the above-described center-of-gravity position detection device, and when the swinging load does not occur, the rope support position is moved to move the suspension load. And a support position movement control unit for generating vibration.

Further, a gravity center position detection device according to still another aspect of the present invention is the above-described gravity center position detection device, wherein the rope length is corrected to include an extension amount of the rope, and the corrected rope length Further, a rope length correction unit for obtaining a distance between the rope support position and the upper surface of the suspended load is provided, and the suspended load center-of-gravity height calculation unit includes the rope support position and the suspended load obtained by the rope length correction unit. Based on the distance from the upper surface, the height of the center of gravity of the suspended load in the suspended load is obtained.

Further, the center-of-gravity position detection device according to yet another aspect of the present invention is the above-described center-of-gravity position detection device, wherein the crane includes a trolley that supports the rope, and the distance calculation unit between the support position center of gravity is The distance between the rope support position and the center of gravity of the suspended load is determined based on the acceleration of the suspended load obtained by adding the swing acceleration of the suspended load to the acceleration of the trolley.

Moreover, the center-of-gravity position detection device according to still another aspect of the present invention is the above-described center-of-gravity position detection device, wherein the suspended load is suspended by a plurality of the ropes, and the tension of each of the ropes, Based on the inclination of each of the ropes relative to the vertical direction, a tension vertical component acquisition unit that obtains a vertical component of the tension of each of the ropes, and based on the vertical component of the tension of each of the ropes, the center of gravity of the suspended load A suspended load center-of-gravity horizontal position calculation unit for obtaining a position in the suspended load in at least one of the horizontal directions.

Further, the center-of-gravity position detection device according to still another aspect of the present invention is the above-described center-of-gravity position detection device, wherein each of the ropes is based on an acceleration at which the rope support position moves and a load of the suspended load. An acceleration / deceleration tension correction unit that performs correction for subtracting a component based on acceleration / deceleration of the rope support position from a vertical component of tension of the tension, and the suspended load center-of-gravity horizontal position calculation unit includes the corrected vertical component of tension The position of the center of gravity of the suspended load in the suspended load is obtained.

According to still another aspect of the present invention, the center-of-gravity position detection device is the above-described center-of-gravity position detection device, wherein a timing detection unit that detects a timing at which the suspended load is positioned at the center of deflection, and the suspended load includes: A tension acquisition unit that acquires the tension of each of the ropes at a timing that is located at the center of the swing, and the tension vertical component acquisition unit is configured so that each of the ropes at a timing at which the suspended load is positioned at the center of the swing. Based on the tension, the vertical component of each tension of the rope is determined.

The center-of-gravity position detection device according to yet another aspect of the present invention is the above-described center-of-gravity position detection device, wherein each tension of the rope in a state where the suspended load is not suspended is determined from each tension of the rope. And a tension component correction unit that performs correction for subtracting the tension, and the tension vertical component acquisition unit obtains the corrected vertical component of each tension of the rope.

According to still another aspect of the present invention, there is provided a center-of-gravity position detection method for a center-of-gravity position detection device that obtains the center-of-gravity position of a suspended load suspended from a rope support position by a crane. A distance calculation step between the support positions and the center of gravity of the suspended load, and a distance between the rope support position and the center of gravity of the suspended load is subtracted from the distance between the rope support position and the center of gravity of the suspended load. Then, a suspended load center-of-gravity height calculation step for obtaining a height of the center of gravity of the suspended load in the suspended load is provided.

According to still another aspect of the present invention, there is provided a program for a computer serving as a center of gravity position detecting device for obtaining a center of gravity position of a suspended load suspended from a rope support position by a crane. A support position center-of-gravity distance calculating step for obtaining a distance to the center of gravity; and a center of gravity of the suspended load by subtracting a distance between the rope support position and the upper surface of the suspended load from a distance between the rope support position and the center of gravity of the suspended load. This is a program for executing a suspended load center-of-gravity height calculating step for obtaining the height of the suspended load in the suspended load.

According to the present invention, the position of the center of gravity in the height direction can be obtained more accurately.

It is a schematic block diagram which shows the function structure of the gravity center position detection apparatus in the 1st Embodiment of this invention. It is explanatory drawing which shows the example of suspension of the suspended load by the crane in the same embodiment. It is explanatory drawing of the positional relationship of the rope support position and suspension load center at the time of trolley traversing of the embodiment. It is a flowchart which shows the process sequence in which the gravity center position detection apparatus in the same embodiment calculates | requires the height of the gravity center of a suspended load. It is explanatory drawing which shows the example of the swing period of the hanging load in the same embodiment. In the same embodiment, when the distance calculation unit between the support position center of gravity calculates the distance between the rope support position and the center of gravity of the suspended load from the suspended load swing period, the center of gravity position detection device determines the height of the center of gravity of the suspended load. It is a flowchart which shows a procedure. It is a schematic block diagram which shows the function structure of the gravity center position detection apparatus in the 2nd Embodiment of this invention. In the same embodiment, it is explanatory drawing which shows the example of the state which hangs a suspended load using four ropes. It is explanatory drawing which shows the example of the timing which the timing detection part in the embodiment detects. It is a flowchart which shows the process sequence in which the gravity center position detection apparatus in the same embodiment calculates | requires the position of the horizontal direction of the gravity center of a suspended load.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

<First Embodiment>
FIG. 1 is a schematic block diagram showing a functional configuration of the center-of-gravity position detection apparatus according to the first embodiment of the present invention. In the figure, the center-of-gravity position detection apparatus 100 includes a data acquisition unit 101, a support position movement control unit 102, a support position center-of-gravity distance calculation unit 103, a rope length correction unit 104, and a suspended load in-center centroid height calculation unit 105. And a display unit 106. The center-of-gravity position detection device 100 is a device that obtains the center-of-gravity position of a suspended load suspended by a rope from a rope support position by a crane. (Height) ”.
Here, FIG. 2 is explanatory drawing which shows the example of suspension of the suspended load by a crane. In the drawing, a crane trolley 910, a rope 920, a spreader 930, and a container as an example of a suspended load C11 are shown. The suspended load C <b> 11 is held by the spreader 930 and is suspended from the trolley 910 by the rope 920.
The trolley 910 supports the rope 920 on its lower surface, and the position where the trolley 910 supports the rope 920 corresponds to an example of the rope support position.

The center-of-gravity position detection device 100 obtains the height of the center of gravity of the suspended load C11 in a state where the suspended load C11 is suspended from the crane.
The center-of-gravity position detection device 100 is not limited to a suspended load suspended on a crane including a trolley, and can be applied to the calculation of the height of the center of gravity of various suspended loads suspended in a state where a swing can occur. For example, the center-of-gravity position detection device 100 can calculate the height of the center of gravity of a suspended load suspended from a jib on a crane having a turnable jib.

The data acquisition unit 101 acquires sensing data from various sensors provided on the crane.
The distance calculation part 103 between support position gravity centers calculates | requires the distance of a rope support position and the gravity center of the suspended load C11. More specifically, the support position center-of-gravity distance calculation unit 103 determines the rope support position based on the swing amount of the suspended load C11 and the acceleration of the suspended load C11 when the suspended load C11 is shaken. And the center of gravity of the suspended load C11. More specific contents of the processing performed by the support position centroid distance calculation unit 103 will be described later.

The support position movement control unit 102 moves the rope support position to cause the suspended load C11 to shake when the suspended load C11 is not shaken. That is, when the distance calculation unit 103 between the support position centroids calculates the distance between the rope support position and the center of gravity of the suspended load C11, the suspended position C11 needs to be shaken. The swing of the suspended load C11 is intentionally generated.
The suspended load center-of-gravity height calculation unit 105 subtracts the distance between the rope support position and the suspended load upper surface from the distance between the rope support position and the suspended load C11 and calculates the difference between the suspended load upper surface and the suspended load C11 center of gravity. Find the distance. The suspended load center-of-gravity height calculation unit 105 subtracts the distance between the suspended load upper surface and the suspended load C11 from the height of the suspended load C11 to obtain the height of the suspended load C11.

The rope length correction unit 104 performs correction to include the extension amount of the rope 920 in the length of the rope 920, and obtains the distance between the rope support position and the suspended load upper surface from the corrected length of the rope 920. That is, the rope 920 that suspends the suspended load C11 is extended by the weight of the suspended load C11 and the like, so that the distance between the rope support position and the upper surface of the suspended load is increased. Therefore, the rope length correction unit 104 corrects the elongation. Do. As the rope length correction unit 104 performs the correction, the suspended load center-of-gravity height calculation unit 105 determines the center of gravity of the suspended load C11 based on the distance between the rope support position obtained by the rope length correction unit 104 and the suspended load upper surface. Can be obtained more accurately.
The display unit 106 has a display screen capable of displaying characters, such as a liquid crystal panel or an organic EL (Organic Electroluminescence) panel, and displays various types of information. In particular, the display unit 106 displays the height of the center of gravity of the suspended load C11 obtained by the suspended load in-center centroid height calculating unit 105.

Next, with reference to FIG. 3, processing performed by the support position centroid distance calculation unit 103 will be described.
FIG. 3 is an explanatory diagram of the positional relationship between the rope support position and the suspended load core when traversing the trolley. In FIG. 3, x ₁ indicates the position of the trolley 910 (distance from the reference point). Further, x ₂ represents the deflection displacement of the suspended load C11 relative to the rope supporting position P11, theta denotes the deflection angle of the suspended load C11 relative to the vertical line L11. Further, l represents the distance between the rope support position P11 and the center of gravity P12 of the suspended load C11, and m represents the load of the suspended load C11.
In the following, as shown in FIG. 3, the rope 920 and the suspended load C <b> 11 shown in FIG. 2 are approximated by a model in which the suspended load C <b> 11 is suspended by a single rope 920. From this FIG. 3, the equation of motion shown in equation (1) can be obtained.

However, g shows a gravitational acceleration. Double dots indicate second order differentiation.
Here, since sin θ = x ₂ / l, equation (2) can be obtained from equation (1).

From equation (2), the distance l is expressed as equation (3).

Based on the equation (3), the supporting position the distance between the centers of gravity calculation unit 103, the shake displacement _{x 2} of the suspended load C11, the acceleration _{x 1} of the trolley 910 (double dot), shake acceleration _x 2 of the suspended load C11 ( From the double dot), the distance l between the rope support position P11 and the center of gravity P12 of the suspended load C11 is obtained. That is, the support position center-of-gravity distance calculation unit 103 calculates the distance between the rope support position P11 and the center of gravity P12 of the suspended load C11 based on the acceleration of the suspended load C11 obtained by adding the swing acceleration of the suspended load C11 to the acceleration of the trolley 910. Ask.

Incidentally, shake displacement x ₂ of the suspended load C11 can be determined using, for example, vibration sensor.
Specifically, a CCD camera for imaging downward from the trolley 910 is installed, the light source provided on the hanging tool (for example, the spreader 930 in FIG. 2) is imaged, and the shake displacement x ₂ is calculated based on the position of the light source in the captured image. calculate. In this case, since the CCD camera is provided in the trolley 910, it is not necessary to provide the shock countermeasure against deflection of the suspended load C11, also, it is possible to obtain the displacement x ₂ shake with high accuracy without receiving such an impact.

Alternatively, an acceleration sensor provided in the load block may be obtained displacement x ₂ shake acceleration detected by the acceleration sensor 2 order integration. In this case, an increase in equipment cost can be suppressed in that an acceleration sensor is used.
Alternatively, it is also possible to determine the displacement x ₂ shake from the torque of the transverse motor of the trolley 910. In this case, for example, torque can be obtained from the current value and motor characteristics of the traversing motor, and there is no need to provide a new sensor.

Further, the acceleration x ₁ (double dot) of the trolley 910 can be obtained by detecting and differentiating the trolley speed using, for example, a trolley speed detector. In particular, when a trolley speed detector is already provided for trolley control or the like, the trolley detector can be used for acceleration detection, and there is no need to provide a new sensor.

Further, the shake acceleration x ₂ (double dot) of the suspended load C11 is obtained, for example, by second-order differentiation of the shake displacement x ₂ obtained using the shake sensor. In this case, as described above, it is not necessary to take measures against impacts, and the shake acceleration x ₂ (double dot) can be obtained with high accuracy without receiving such impacts.
Alternatively, an acceleration meter may be provided on the hanging tool to measure the shake acceleration x ₂ (double dot). In this case, similarly to the above, an increase in equipment cost can be suppressed.

Next, the operation of the gravity center position detection apparatus 100 will be described with reference to FIG.
FIG. 4 is a flowchart illustrating a processing procedure in which the gravity center position detection device 100 obtains the height of the gravity center of the suspended load C11. The center-of-gravity position detection device 100 performs the process shown in FIG.
In the process of FIG. 4, first, the data acquisition unit 101 acquires the acceleration of the trolley 910, the swing acceleration of the suspended load C11, the swing displacement of the suspended load C11, the length of the rope 920, and the load of the suspended load C11. (Step S101).

When the swing of the suspended load C11 is small, the support position movement control unit 102 outputs a control signal instructing traverse inching (short traverse) to the trolley 910, and intentionally causes residual swing. And the data acquisition part 101 acquires the acceleration of the trolley 910, the swing acceleration of the suspended load C11, and the deflection displacement of the suspended load C11 again in the state in which the suspended load C11 has shaken.
The length of the rope 920 can be obtained by, for example, detecting the rotation of the winding drum of the trolley 910 with an encoder and calculating the winding length or rewinding length of the rope 920 from the number of rotations of the drum. In particular, it is expected that the crane already has a mechanism for detecting the winding length and the rewinding length for hoisting control, and in this case, it is not necessary to provide a new sensor.
Further, in the method of obtaining the rope length from the rotation speed of the drum, the rope length can be detected with high accuracy.

Next, as described with reference to FIG. 3, the support position center-of-gravity distance calculation unit 103 calculates the rope support position from the acceleration of the trolley 910, the swing acceleration of the suspended load C11, and the swing displacement of the suspended load C11. And the center of gravity of the suspended load C11 are obtained (step S102).
Further, the rope length correction unit 104 calculates the elongation amount of the rope 920 from the load of the suspended load C11, the length of the rope 920, and the Young's modulus of the rope 920, and includes the calculated elongation amount in the length of the rope 920. Correction is performed (step S103). That is, the rope length correction unit 104 adds the calculated amount of elongation and the length of the rope 920 acquired by the data acquisition unit 101.

In the case of the example illustrated in FIG. 2, the rope length correction unit 104 performs correction to include the extension amount in the length of the rope 920, for example, for each of the four ropes 920, and averages the lengths of the four ropes 920 after correction. The value is determined as the length of the rope 920. In the example shown in FIG. 2, the distance from the rope support position to the upper surface of the suspended load C11 and the length of the rope 920 can be viewed together. Therefore, the rope length correction unit 104 outputs the calculated average value to the suspended load center-of-gravity height calculation unit 105 as the distance from the rope support position to the upper surface of the suspended load C11.

Next, the suspended load center-of-gravity height calculation unit 105 calculates the rope support position calculated by the rope length correction unit 104 from the distance between the rope support position calculated by the support position center-of-gravity distance calculation unit 103 and the center of gravity of the suspended load C11. The distance between the upper surface of the suspended load C11 (for example, approximated by the lower surface of the spreader 930) is subtracted to obtain the distance between the suspended load upper surface and the center of gravity of the suspended load C11 (step S104). The suspended load center-of-gravity height calculation unit 105 subtracts the distance between the suspended load upper surface and the suspended load C11 from the height of the suspended load C11 to obtain the height of the suspended load C11.
If the inclination of the rope 920 from the vertical direction cannot be ignored, the suspended load center-of-gravity height calculation unit 105 multiplies the distance between the suspended load upper surface and the center of gravity of the suspended load C11 by the cosine of the inclined load, The distance from the center of gravity of the suspended load C11 may be corrected.
Then, the display unit 106 displays the height of the center of gravity of the suspended load C11 calculated by the suspended load center-of-gravity height calculation unit 105 (step S105).
Thereafter, the process of FIG. 4 is terminated.

As described above, the support position center-of-gravity distance calculation unit 103 obtains the distance between the rope support position and the center of gravity of the suspended load, and the suspended load center-of-gravity height calculation unit 105 calculates the distance between the rope support position and the center of gravity of the suspended load. The height of the center of gravity of the suspended load is obtained by subtracting the distance between the rope support position and the upper surface of the suspended load.
Thereby, the center-of-gravity position detection apparatus 100 can obtain the height of the center of gravity of the suspended load without using radiation, and the center of gravity (height direction) of the suspended load regardless of the radiation transmission amount of the suspended load. Can be determined more accurately.

Further, the support position center-of-gravity distance calculation unit 103 calculates the distance between the rope support position and the center of gravity of the suspended load based on the amount of swing of the suspended load and the acceleration of the suspended load when the suspended load is shaken. Find the distance.
As described above, the support position center-of-gravity distance calculation unit 103 can obtain the distance between the rope support position and the center of gravity of the suspended load using easily measurable data such as the amount of swing of the suspended load and the acceleration of the suspended load. it can.

In addition, when there is no vibration in the suspended load, the support position movement control unit 102 moves the rope support position to generate the vibration in the suspended load.
As a result, it is possible to avoid a situation in which the distance between the support position center of gravity calculation unit 103 cannot obtain the distance between the rope support position and the center of gravity of the suspended load because there is no vibration in the suspended load.

Also, the rope length correction unit 104 performs correction to include the amount of elongation of the rope in the rope length. Thereby, the suspended load in-center centroid height calculation part 105 can calculate | require the height of the centroid of an suspended load more correctly.

The method for calculating the distance between the support position center of gravity and the distance between the rope support position and the center of gravity of the suspended load is not limited to the method described with reference to FIG. For example, the support position center-of-gravity distance calculation unit 103 obtains the distance between the rope support position and the center of gravity of the suspended load based on the swing period of the suspended load in a state where the suspended load is shaken. Also good.

FIG. 5 is an explanatory diagram illustrating an example of a swinging period of a suspended load. In the figure, a line L21 indicates the traversing speed of the trolley 910, and a line L22 indicates the deflection displacement of the suspended load C11. The trolley 910 traverses and stops until time T21, and as shown by the line L22 in the area A21 in the figure, after the time T21, the suspended swing C11 has a residual swing with a period T.
When this residual shake is approximated by the movement of a single pendulum, the period and angular frequency of the residual shake depend on the length of the pendulum (that is, the distance between the rope support position and the center of gravity of the suspended load C11). More specifically, from the above equation (2), the angular frequency ω of the swing of the suspended load C11 is expressed as in equation (4).

Further, the swing period T of the suspended load C11 is expressed by the equation (5).

Here, π represents the circumference ratio.
Equation (6) is obtained from Equation (4) and Equation (5).

From equation (6), the distance l between the rope support position and the center of gravity of the suspended load is given by equation (7).

Based on this formula (7), the distance calculation section 103 between the support position centroids calculates the distance l between the rope support position P11 and the centroid P12 of the suspended load C11 from the swing period T of the suspended load C11.
Incidentally, swinging period T of the suspended load C11 can be determined from the time series of vibration displacement _{x 2} of the suspended load C11. Therefore, as described above, the swing period T can be obtained using, for example, a swing sensor or an acceleration sensor provided on a hanging tool, or from the torque of the traversing motor of the trolley 910.

FIG. 6 shows that the center-of-gravity position detecting device 100 determines the height of the center of gravity of the suspended load C11 when the distance calculation unit 103 between the support positions calculates the distance between the rope support position and the center of gravity of the suspended load C11 from the swing period of the suspended load C11. It is a flowchart which shows the process sequence which calculates | requires thickness. The center-of-gravity position detection apparatus 100 performs the process of FIG. 6 instead of the process of FIG. 4 in a state where the trolley 910 stops traversing.

In the process of FIG. 6, first, the data acquisition unit 101 acquires the data of the deflection displacement of the suspended load C11 and detects the amplitude of the remaining deflection of the suspended load C11 after the trolley traverse stop (step S201).
Then, the support position movement control unit 102 compares the amplitude detected by the data acquisition unit 101 with a predetermined threshold value to determine whether or not the residual vibration of the suspended load C11 is sufficiently large (step S202).
When it is determined that the residual shake is not sufficiently large (step S202: NO), the support position movement control unit 102 outputs a control signal for instructing traverse inching to the trolley 910, and intentionally causes the residual shake (step S211). ).

Next, the data acquisition unit 101 acquires the data of the deflection displacement of the suspended load C11 and detects the period of the remaining deflection of the suspended load C11 after the trolley traverse stop (step S221).
Then, as described with reference to FIG. 5, the support position center-of-gravity distance calculation unit 103 obtains the distance between the rope support position and the center of gravity of the suspended load C11 based on the swing period of the suspended load (step S222). .
Further, the data acquisition unit 101 acquires the length of the rope 920 (step S223).

Hereinafter, steps S224 to S226 are the same as steps S103 to S105 of FIG. After step S226, the process of FIG. 6 ends.
If it is determined in step S202 that the residual shake is sufficiently large (step S202: YES), the process proceeds to step S221.

As described above, the support position center-of-gravity distance calculation unit 103 obtains the distance between the rope support position and the center of gravity of the suspended load based on the swing period of the suspended load in a state where the suspended load is shaken. .
Thereby, the distance calculation part 103 between support position gravity centers can calculate the period of a suspended load from the data which can be measured easily, such as a displacement of a suspended load, and can obtain | require the distance of a rope support position and the gravity center of a suspended load. .

<Second Embodiment>
FIG. 7 is a schematic block diagram showing a functional configuration of the center-of-gravity position detection device according to the second embodiment of the present invention. In the figure, the center-of-gravity position detection apparatus 200 includes a data acquisition unit 101, a support position movement control unit 102, a support position center-of-gravity distance calculation unit 103, a rope length correction unit 104, and a suspended load in-center centroid height calculation unit 105. A display unit 106, a timing detection unit 201, an acceleration / deceleration tension correction unit 202, a tension vertical component acquisition unit 203, a suspension component tension correction unit 204, and a suspended load center of gravity horizontal position calculation unit 205. It has. In the same figure, portions having the same functions corresponding to the respective portions in FIG. 1 are denoted by the same reference numerals (101 to 106), and description thereof is omitted.
Note that the data acquisition unit 101 in the present embodiment corresponds to an example of a tension acquisition unit in the present invention.

In addition to the height of the center of gravity of the suspended load C11, the center-of-gravity position detection device 200 has a horizontal position within the suspended load C11 of the center of gravity of the suspended load C11 (hereinafter referred to as “the horizontal position of the center of gravity of the suspended load”). Ask). Specifically, the center-of-gravity position detection device 200 determines the horizontal position of the center of gravity of the suspended load C11 in the traversing direction of the trolley 910 and the traveling direction of the trolley 910 (perpendicular to the traversing direction).

The tension vertical component acquisition unit 203 obtains the vertical component of each tension of the rope 920 based on the tension of each of the plurality of ropes 920 that suspends the suspended load C11 and the inclination of each of the ropes 920 with respect to the vertical direction. . Specific contents of the processing performed by the tension vertical component acquisition unit 203 will be described later.
The suspended load center-of-gravity horizontal position calculation unit 205 obtains the position of the center of gravity of the suspended load C11 in the suspended load based on the vertical component of the tension of each rope 920 in at least one of the horizontal directions. More specifically, the suspended load center-of-gravity horizontal position calculation unit 205 determines that the rope 920 is suspended in the horizontal direction based on the ratio of the vertical components of the tensions of the ropes 920 obtained by the tension vertical component acquisition unit 203. The ratio of the distance between each point supporting C11 and the center of gravity is obtained, and the horizontal position of the center of gravity of the suspended load C11 is obtained from the ratio.

The timing detection unit 201 detects the timing at which the suspended load C11 is located at the center of the swing. By using the data at the timing detected by the timing detection unit 201, the center-of-gravity position detection device 200 can reduce the influence of the swing of the suspended load C11 and more accurately determine the horizontal position of the center of gravity of the suspended load. it can.

The acceleration / deceleration tension correction unit 202 subtracts the component based on the acceleration / deceleration of the rope support position from the vertical component of the tension of each rope 920 based on the acceleration at which the rope support position moves and the load of the suspended load C11. I do. The acceleration / deceleration tension correction unit 202 performs the correction, so that the center-of-gravity position detection device 200 reduces the influence of the completion force of the suspended load C11 even during the acceleration / deceleration of the trolley 910, thereby leveling the center of gravity of the suspended load. The position in the direction can be obtained more accurately.
The suspension component tension correction unit 204 performs correction by subtracting each tension of the rope in a state where the suspended load is not suspended from each tension of the rope. When the lifting device tension correction unit 204 performs the correction, the center-of-gravity position detection device 200 reduces the error due to the weight of the lifting device and more accurately obtains the horizontal position of the center of gravity of the suspended load. be able to.

Next, processing performed by the tension vertical component acquisition unit 203 will be described with reference to FIG.
FIG. 8 is an explanatory diagram illustrating an example of a state in which a suspended load is suspended using four ropes. In the figure, the suspended load C11 is suspended from rope support positions (points FR1, FL1, AR1, and AL1) by four ropes 920. Here, the points FR1, FL1, AR1, AL1 coordinates, _{respectively, (x 1FR, y 1FR,} z 1FR), (x 1FL, y 1FL, z 1FL), (x 1AR, y 1AR, z 1AR), ( _X1AL , _y1AL , _z1AL ).
The x coordinate is taken in the traveling direction, the y coordinate is taken in the transverse direction, and the z coordinate is taken upward in the vertical direction.

The four ropes are connected to the spreader 930 at points FR2, FL2, AR2, and AL2, respectively, and suspend a suspended load C11 that is held by the spreader 930. Here, the coordinates of the points FR2, FL2, AR2, AL2 are respectively (x _2FR , y _2FR , z _2FR ), (x _2FL , y _2FL , z _2FL ), (x _2AR , y _2AR , z _2AR ), (X _2AL , y _2AL , z _2AL ).

Various methods can be used as a method for obtaining the coordinates of the points FR2, FL2, AR2, and AL2.
For example, the points FL1 and FR1 are moved from the position directly above the points FL2 and FR2 by the same distance (in other words, line-symmetric), and the distance between _x1FL , _x1FR , the point FL1 and the point FR1, and the point You may make it obtain _| require _x2FL and _x2FR based on the distance of FL2 and point FR2. Other coordinate values can be obtained in the same manner by moving similarly for FL1 and AL1, FR1 and AR1, and AL1 and AR1.
Alternatively, an image including the point FL2, the point FR2, the point AL2, and the point AR2 may be captured from a camera installed at a fixed point, and the coordinates of each point may be obtained from the captured image.

In addition, the inclination of the rope 920 connecting the point FR1 and the point FR2 with the vertical direction is represented by an angle θ _FR . Similarly, the inclination of the rope 920 connecting the point FL1 and the point FL2 with the vertical direction is represented by an angle θ _FL , and the inclination of the rope 920 connecting the point AR1 and the point AR2 with the vertical direction is represented by an angle θ _AR. connecting the AL1 and point AL2 represents the inclination of the vertical direction of the rope 920 at an angle theta _AL.
Point O ′ indicates the center position of the points FR2, FL2, AR2, and AL2, and point G indicates the center of gravity of the suspended load C11.
From FIG. 8, the angle θ _FR of the slope of the rope with respect to the vertical direction is expressed as in Expression (8).

The tension vertical component acquisition unit 203 calculates the value of the angle θ _FR based on Expression (8). The same applies to θ _FL , θ _AR , and θ _AL .
Further, the vertical component of the tension can be obtained based on the equation (9) using the value of the inclination θ _{FR and} the value of the tension tens_FR of the rope 920.

The tension vertical component acquisition unit 203 calculates the tension vertical component M _FR based on the equation (9). The same applies to M _FL , M _AR , and M _AL .
Based on the ratio of the vertical components of the tension of each of the ropes 920 obtained by the tension vertical component acquisition unit 203, the suspended load center-of-gravity horizontal position calculation unit 205 uses a known method in the horizontal direction of the center of gravity of the suspended load C11. The position can be determined. More specifically, the suspended load center-of-gravity horizontal position calculation unit 205 determines that the rope 920 is suspended in the horizontal direction based on the ratio of the vertical components of the tensions of the ropes 920 obtained by the tension vertical component acquisition unit 203. The ratio of the distance between each point supporting C11 and the center of gravity is obtained, and the horizontal position of the center of gravity of the suspended load C11 is obtained from the ratio.

During the transverse acceleration / deceleration, the inertial force of the suspended load is applied to the tension detector (eg, load cell) of the rope 920, so that the acceleration / deceleration tension correction unit 202 performs the suspended load Mall and the transverse acceleration / deceleration x ₁ (double dot). ) And the correction is performed based on the equation (10).

The load Mall here is a total value of weights in a state where the trolley is not performing transverse acceleration / deceleration. This load Mall is measured, for example, when the trolley is stopped or at a constant speed. Or you may make it use the load calculation value at the time of the suspended load winding by a winding inverter as the load Mall. The acceleration / deceleration tension correction unit 202 performs the correction, so that the center-of-gravity position detection device 200 reduces the influence of the inertial force of the suspended load during the transverse acceleration / deceleration, thereby further increasing the horizontal position of the suspended load's center of gravity. It can be determined accurately. The same applies to the tensions tens_FL, tens_AR, and tens_AL.
Alternatively, instead of the correction by the acceleration / deceleration tension correction unit 202, the data acquisition unit 101 may acquire the tensions tens_FR, tens_FL, tens_AR, and tens_AL after waiting for a state where the trolley is not performing the lateral acceleration / deceleration.

Further, when the suspended load C11 is shaken, the timing detection unit 201 detects the timing at which the suspended load C11 is located at the center of the shake, and the data acquisition unit 101 detects the tension of each rope 920 at the timing. get.
FIG. 9 is an explanatory diagram illustrating an example of timing detected by the timing detection unit 201. In the figure, a line L31 indicates the deflection displacement of the suspended load C11. A line L32 indicates the center of the swing of the suspended load C11. The center of the runout corresponds to the position of the suspended load C11 when the runout of the suspended load C11 has subsided.

The timing detection unit 201 detects the timing at which the suspended load C11 is located at the center of the shake as at time T31. The data acquisition unit 101 acquires the tension of each of the ropes at the timing detected by the timing detection unit 201, so that the center-of-gravity position detection device 200 reduces the influence of the swing of the suspended load C11 and the center of gravity of the suspended load. The position in the horizontal direction can be determined more accurately.
The timing in the center of the deflection is suspended load C11 can be obtained from the time series of vibration displacement x ₂ of the suspended load C11. Therefore, as described above, the timing can be obtained using, for example, a vibration sensor or an acceleration sensor provided on the hanging tool, or from the torque of the traversing motor of the trolley 910.

Note that when the center of shake is detected using the shake sensor, an offset error due to the tilt of the shake sensor camera or the like may occur in the detection value of the shake sensor. In this case, the center of the shake is determined by removing the offset error with a high-pass filter or the like. Alternatively, the timing detection unit 201 may detect the maximum swing speed as the timing at which the suspended load C11 is positioned at the center of the swing.

Further, the timing detection unit 201 may detect the timing at which the suspended load C11 is located at the center of the swing a plurality of times. For example, the timing detection unit 201 detects data by averaging the data at a plurality of timings, such as calculating the horizontal position of the center of gravity of the suspended load at each timing and calculating the horizontal position of the center of gravity of the suspended load. And the influence of the deviation between the timing at which the suspended load C11 is located at the center of the swing can be reduced.

Note that an allowable range of errors included in the timing detected by the timing detection unit 201 can be set according to the target accuracy of the center of gravity detection. For example, when the target accuracy of the center of gravity position is plus or minus (±) 10 percent (%), the range of 1/10 plus or minus 1 percent of the deflection angle can be set as the allowable range. For example, if the rope length is 10 meters (m), the timing detection unit 201 is set to detect the timing when the suspended load C11 is within a range of plus or minus 0.1 meters from the center of the swing.

Moreover, the load block content tension correcting unit 204, the vertical component of the tension in a state where the vertical component _M FR tension in a state that hung suspended _load, from M _{FL, M AR} and _{M AL,} not hung suspended load M _FR0 , M _FL0 , M _AR0 , and M _AL0 are subtracted to obtain vertical components M _FRC , M _FLC , M _ARC , and M _ALC of tension based on the suspended load.
For this purpose, the vertical component of tension (M _FR0 , M _FL0 , M _AR0 and M _AL0 ) is obtained by performing the same processing as when the suspended load is suspended in the state where the suspended load is not suspended. The correction unit 204 stores in advance.

Next, the operation of the gravity center position detection apparatus 200 will be described with reference to FIG.
FIG. 10 is a flowchart illustrating a processing procedure in which the center-of-gravity position detection device 200 calculates the position of the center of gravity of the suspended load C11 in the transverse direction. The center-of-gravity position detection apparatus 200 performs the processing shown in FIG.
In the process of FIG. 10, first, the data acquisition unit 101 acquires the deflection displacement of the suspended load C11, and as described with reference to FIG. 9, the timing detection unit 201 positions the suspended load C11 at the center of the deflection. Timing is detected (step S301).

Next, the data acquisition unit 101 acquires the tension at each rope support position of the rope 920 (step S302).
In addition, the tension | tensile_strength in each rope support position of the rope 920 can be measured using the tension meter (for example, load cell) installed in each of a rope support position, for example. By measuring the tension using a load cell, the tension of the rope can be accurately detected. Moreover, when the load cell is already provided in the rope support position, it is not necessary to provide a new sensor.
Or you may make it obtain | require the tension | tensile_strength in a rope support position by methods other than the method of using a load cell, such as using a strain gauge.

Also, the data acquisition unit 101 acquires the coordinates of each rope support position (step S303). For example, each rope support position is movably provided in a sheave opening / closing cylinder, and the data acquisition unit 101 receives a signal from an encoder that detects the displacement of the cylinder and calculates the coordinates of the rope support position.

Further, the data acquisition unit 101 acquires the length of each rope 920 (step S304).
Next, the tension vertical component acquisition unit 203 calculates the inclination with respect to the vertical direction for each of the ropes 920 (step S305).
In addition, the data acquisition unit 101 acquires the acceleration of the trolley 910 and determines whether the trolley 910 is traversing acceleration / deceleration (step S306).

When it is determined that traverse acceleration / deceleration is in progress (step S306: YES), the acceleration / deceleration tension correction unit 202 determines each tension of the rope 920 based on the acceleration at which the rope support position moves and the load of the suspended load C11. Correction for subtracting the component based on the acceleration / deceleration of the rope support position from the vertical component is performed (step S307). Or you may make it return to step S306 and wait for completion | finish of transverse acceleration / deceleration.
Next, the tension vertical component acquisition unit 203 is based on the inclination obtained in step S305, and the vertical component of each tension of the rope 920 (or the corrected tension when the acceleration / deceleration tension correction unit 202 performs correction). Is calculated (step S308).

And the tension | tensile_strength part correction | amendment correction | amendment part 204 performs correction | amendment which subtracts the perpendicular | vertical component for suspension from the perpendicular | vertical component of each tension | tensile_strength of the rope 920 which the tension | tensile_strength perpendicular | vertical component acquisition part 203 calculated | required (step S309). Here, in the state where the suspended load C11 is not suspended, the processes of steps S301 to S308 are performed to obtain the vertical component for the hanging tool, and the hanging tool tension correcting unit 204 stores it in advance.
In addition, when the weight of the hanging tool can be ignored with respect to the weight of the hanging load, step S309 can be omitted.

Next, the suspended load center-of-gravity horizontal position calculation unit 205 calculates the position of the center of gravity of the suspended load C11 in the transverse direction based on the corrected vertical component of the lifting device tension correction unit 204 (step S310).
Then, the display unit 106 displays the horizontal direction position of the center of gravity of the suspended load C11 calculated by the suspended load center of gravity horizontal position calculating unit 205 (step S311).
Then, the process of FIG. 10 is complete | finished.
If it is determined in step S306 that the trolley 910 is not in the transverse acceleration / deceleration (step S306: NO), the process proceeds to step S308. That is, the processing of the acceleration / deceleration tension correction unit 202 is omitted.

The center-of-gravity position detection device 200 determines the center-of-gravity position in the X direction (traveling direction) as in the case of the Y direction. However, traverse acceleration / deceleration is replaced with travel acceleration / deceleration. Further, the traverse motor torque is replaced with the travel motor torque. Further, the transverse direction shake is replaced with the running direction shake. When determining the center of gravity position, the sum of the tensions of the two front and rear points on the right side (FR1 and AR1 in the example of FIG. 8) and the front and rear two points (FL1 and AL1 in the example of FIG. 8). The position of the center of gravity is obtained from the ratio with the sum of the tensions.

As described above, the tension vertical component acquisition unit 203 obtains the vertical component of the tension of each rope 920 based on the tension of each rope 920 and the inclination of each rope 920 with respect to the vertical direction. Then, the suspended load center-of-gravity horizontal position calculation unit 205 obtains the horizontal position of the center of gravity of the suspended load C11 based on the vertical component of the tension of each rope 920.
Thereby, the center-of-gravity position detection apparatus 200 can obtain the horizontal position of the center of gravity of the suspended load C11 based on data that can be easily measured, such as the rope support position, the length of the rope 920, and the tension of the rope 920.

Further, the acceleration / deceleration tension correction unit 202 subtracts the component based on the acceleration / deceleration of the rope support position from the vertical component of each tension of the rope 920 based on the acceleration at which the rope support position moves and the load of the suspended load C11. Make corrections.
Thereby, the center-of-gravity position detection device 200 can reduce the influence of the completion force of the suspended load C11 even during acceleration / deceleration of the trolley 910, and can more accurately determine the horizontal position of the center of gravity of the suspended load.

The timing detection unit 201 detects the timing at which the suspended load C11 is positioned at the center of the swing, and the data acquisition unit 101 acquires the tension of each of the ropes 920 at the timing at which the suspended load C11 is positioned at the center of the swing. . By using the data at the timing detected by the timing detection unit 201, the center-of-gravity position detection device 200 can reduce the influence of the swing of the suspended load C11 and more accurately determine the horizontal position of the center of gravity of the suspended load. it can.

Also, the lifting device tension correction unit 204 performs correction to subtract each tension of the rope 920 in a state where the suspended load C11 is not suspended from each tension of the rope 920. Thereby, the center-of-gravity position detecting device 200 can reduce the error due to the weight of the hanging tool and more accurately determine the horizontal position of the center of gravity of the suspended load.

It should be noted that the second embodiment can be implemented independently of the first embodiment. For example, the center-of-gravity position detection device excluding the support position center-of-gravity distance calculation unit 103, the rope length correction unit 104, and the suspended load center of gravity height calculation unit 105 from the configuration illustrated in FIG. You can ask for the position.

It should be noted that a program for realizing all or part of the functions of each part of the gravity center position detection apparatus 100 or 200 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read by a computer system. The processing of each unit may be performed by executing. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention.

The present invention is a center-of-gravity position detection device for obtaining a center of gravity position of a suspended load suspended from a rope support position by a crane, and a distance between the support position centers of gravity for obtaining a distance between the rope support position and the center of gravity of the suspended load. A suspension for calculating the height of the center of gravity of the suspended load in the suspended load by subtracting the distance between the rope supported position and the upper surface of the suspended load from the distance between the calculating unit and the center of gravity of the suspended load. The present invention relates to a center-of-gravity position detection device comprising:
According to the present invention, the position of the center of gravity in the height direction can be obtained more accurately.

DESCRIPTION OF SYMBOLS 100,200 Center-of-gravity position detection apparatus 101 Data acquisition part 102 Support position movement control part 103 Support position center-of-gravity distance calculation part 104 Rope length correction part 105 Suspension load center of gravity height calculation part 106 Display part 201 Timing detection part 202 Tension component tension Correction unit 203 Tension vertical component acquisition unit 204 Acceleration / deceleration tension correction unit 205 Center of gravity horizontal position calculation unit in suspended load

Claims (13)

1. A center-of-gravity position detection device for obtaining a center-of-gravity position of a suspended load suspended from a rope support position by a crane,
   A support position center-of-gravity distance calculation unit for obtaining a distance between the rope support position and the center of gravity of the suspended load;
   The center-of-gravity height in the suspended load is obtained by subtracting the distance between the rope support position and the upper surface of the suspended load from the distance between the rope-supported position and the center of gravity of the suspended load to obtain the height of the suspended load's center of gravity in the suspended load. A calculation unit;
   A center-of-gravity position detection device comprising:
2. The distance calculation unit between the support position center of gravity is based on the swing amount of the suspended load and the acceleration of the suspended load in a state where the suspended load is shaken, and the center of gravity of the suspended load and the suspended load. The center-of-gravity position detection device according to claim 1, wherein the distance is calculated.
3. The distance calculation unit between the support position centers of gravity calculates a distance between the rope support position and the center of gravity of the suspended load based on a swing period of the suspended load in a state in which the suspended load is shaken. The center-of-gravity position detection device according to 1.
4. The center-of-gravity position detection device according to claim 2, further comprising a support position movement control unit configured to move the rope support position and generate the shake of the suspended load when the suspended load is not shaken.
5. 4. The center-of-gravity position detection device according to claim 3, further comprising: a support position movement control unit configured to move the rope support position to generate a shake of the suspended load when the suspended load is not shaken.
6. The rope length is corrected to include the amount of the rope in the rope length, and includes a rope length correction unit that determines the distance between the rope support position and the upper surface of the suspended load from the corrected rope length,
   The suspended load center-of-gravity height calculation unit obtains the height of the center of gravity of the suspended load in the suspended load based on the distance between the rope support position and the suspended load upper surface obtained by the rope length correction unit. Item 4. The center-of-gravity position detection device according to Item 1.
7. The crane includes a trolley for supporting the rope;
   The distance calculation unit between the support position centers of gravity calculates a distance between the rope support position and the center of gravity of the suspended load based on the acceleration of the suspended load obtained by adding the swing acceleration of the suspended load to the acceleration of the trolley. The center-of-gravity position detection apparatus according to 2.
8. The suspended load is suspended by a plurality of the ropes,
   A tension vertical component acquisition unit that obtains a vertical component of the tension of each of the ropes based on the tension of each of the ropes and the inclination of each of the ropes with respect to the vertical direction;
   Based on the vertical component of the tension of each of the ropes, the position of the center of gravity of the suspended load in the suspended load, the center of gravity horizontal position calculation unit in the suspended load for obtaining at least one of the horizontal directions, and
   The center-of-gravity position detection device according to claim 1, comprising:
9. Acceleration / deceleration tension correction for correcting the subtraction of the component based on the acceleration / deceleration of the rope support position from the vertical component of the tension of each rope based on the acceleration at which the rope support position moves and the load of the suspended load Comprising
   The gravity center position detection device according to claim 8, wherein the suspended load center-of-gravity horizontal position calculation unit obtains the position of the center of gravity of the suspended load in the suspended load based on the corrected vertical component of the tension.
10. A timing detection unit for detecting the timing at which the suspended load is located at the center of deflection;
    A tension acquisition unit that acquires the tension of each of the ropes at a timing at which the suspended load is located at the center of deflection,
    9. The center-of-gravity position detection according to claim 8, wherein the tension vertical component acquisition unit obtains a vertical component of each tension of the rope based on a tension of each rope at a timing at which the suspended load is located at the center of the swing. apparatus.
11. A tension component correction unit that performs correction for subtracting the tension of each of the ropes in a state in which the suspended load is not suspended from the tension of each of the ropes,
    The center-of-gravity position detection device according to claim 8, wherein the tension vertical component acquisition unit calculates a vertical component of each tension of the rope after correction.
12. A center-of-gravity position detection method for a center-of-gravity position detection device that obtains the position of the center of gravity of a suspended load suspended from a rope support position by a crane,
    A distance calculation step between the support position and the center of gravity to obtain the distance between the rope support position and the center of gravity of the suspended load;
    The center-of-gravity height in the suspended load is obtained by subtracting the distance between the rope support position and the upper surface of the suspended load from the distance between the rope-supported position and the center of gravity of the suspended load to obtain the height of the suspended load's center of gravity in the suspended load. A calculation step;
    A center of gravity position detection method comprising:
13. In the computer as the center of gravity position detection device that obtains the center of gravity position of the suspended load suspended from the rope support position by the crane,
    A distance calculation step between the support position and the center of gravity to obtain the distance between the rope support position and the center of gravity of the suspended load;
    The center-of-gravity height in the suspended load is obtained by subtracting the distance between the rope support position and the upper surface of the suspended load from the distance between the rope-supported position and the center of gravity of the suspended load to obtain the height of the suspended load's center of gravity in the suspended load. A calculation step;
    A program for running

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