JP2012037469A - Center of gravity position measuring equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a center of gravity position measuring equipment for measuring a position of the center of gravity of a load conveyed by a crane without deteriorating working efficiency.SOLUTION: The center of gravity position measuring equipment is configured to detect tensions imposed on four wires 4to 4of a crane 1 by load cells 7to 7when the wires 4to 4are inclined with an inertial force acting upon suspending and horizontally moving a container 5 by the wires 4to 4in cargo work, and to detect angles θ of inclination of the wires 4to 4by inclination sensors 8to 8for calculating a position of the center of gravity of the container 5. Thus, it is possible to calculate the center of gravity position within a horizontal face and a vertical face of the container 5, that is, a three-dimensional center of gravity position without requiring any special operation of inclining the container in order to calculate the center of gravity position of the container as it does in a conventional example.

Description

  The present invention relates to a center-of-gravity position measuring apparatus that measures the position of the center of gravity of a load such as a container carried by a crane.

  When importing / exporting container cargo at ports, etc., the container is loaded and unloaded onto the trailer by a crane, and the container is transported by the trailer. There is an accident that the trailer rolls over.

  Such an unbalance of the load is caused by the center of gravity of the container being biased due to the non-uniform load in the container loaded on the trailer.

  For this reason, before loading a container on a trailer with a crane, it is desired to measure the position of the center of gravity of the container and appropriately load it on the trailer in consideration of the balance of the center of gravity of the container based on the measurement result.

  Conventionally, a center-of-gravity measurement device that measures the position of the center of gravity of a lifted luggage has been proposed (see, for example, Patent Document 1).

JP-A-6-43061

  However, in Patent Document 1, in order to measure the center of gravity position of a load, a special operation of tilting the lifted load must be performed. For example, the load is lifted by a crane and moved in the horizontal direction. In addition to a series of cargo handling operations such as unloading, in order to measure the position of the center of gravity, an operation of tilting the lifted cargo is required, and there is a problem that the efficiency of the cargo handling operation is reduced.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to enable measurement of the position of the center of gravity of a load transported by a crane without reducing work efficiency.

  In order to achieve the above object, the present invention is configured as follows.

  (1) A center-of-gravity position measuring apparatus according to the present invention is a center-of-gravity position measuring apparatus that measures the center-of-gravity position of a load of a crane that lifts and transports a load by a plurality of ropes and moves the load in the horizontal direction. A load sensor that detects each tension acting on each cord body, a tilt sensor that detects a tilt angle of the cord body along with the movement in the horizontal direction, and a detection output of the load sensor and the tilt sensor And calculating means for calculating each gravity center position in a horizontal plane and a vertical plane of the luggage.

  Luggage refers to an article carried by a crane, such as a container.

  A cord means a rope-like thing, for example, a wire, a chain, a rope, etc.

  According to the center-of-gravity position measuring apparatus of the present invention, the load body is lifted by a plurality of crane bodies in a cargo handling operation, and the rope body when the rope body is tilted by an inertial force acting when the load is moved in the horizontal direction. Since it detects the tension applied and the inclination angle of the cable body and uses it to calculate the center of gravity of the load, it does not require special operations such as tilting the load to obtain the center of gravity of the load, as in the conventional example. Therefore, the center of gravity position in the horizontal and vertical planes of the load, that is, the three-dimensional center of gravity position can be obtained without reducing the efficiency of the cargo handling operation.

  (2) In another embodiment of the center-of-gravity position measuring apparatus according to the present invention, the crane lifts the load with at least four of the ropes, and the load sensor is provided for each of the ropes. Each acting tension is detected.

  According to this embodiment, the baggage is stably lifted and transported by at least four cable bodies, and the tension applied to each wire or chain is detected by the load sensor provided for each cable body, whereby the center of gravity of the load is detected. It can be used for position calculation.

  (3) In a preferred embodiment of the center-of-gravity position measuring apparatus of the present invention, the calculation means calculates a center-of-gravity position in a horizontal plane of the load based on a detection output of the load sensor in a state where the load is lifted. The center of gravity position in the vertical plane of the load is calculated based on the load sensor and the detection output of the tilt sensor in a state where the rope body is tilted with the movement in the horizontal direction.

  According to this embodiment, in the state where the luggage is lifted, when the rope body is not vertically inclined, the tension applied to the rope body is detected by the load sensor to calculate the position of the center of gravity in the horizontal plane of the luggage, The load sensor detects the tension applied to the cable body while the cable body is tilted as the luggage moves in the horizontal direction, and the center of gravity position in the vertical plane of the luggage is calculated by detecting the inclination angle using the inclination sensor. can do.

  (4) In another embodiment of the center-of-gravity position measuring apparatus according to the present invention, the computing means lifts the load and based on detection outputs of the load sensor and the tilt sensor in a state where the rope body is tilted. A center of gravity in a vertical plane of the load is calculated based on a detection output of the load sensor and the tilt sensor in a state in which the cord body is tilted with the movement in the horizontal direction. Calculate the position.

  According to this embodiment, when the cable body is inclined with the load being lifted, the tension applied to the cable body is detected by the load sensor, and the inclination angle is detected by the inclination sensor and the center of gravity in the horizontal plane of the load is detected. The position is calculated, and the tension applied to the cable body is detected by the load sensor while the cable body is inclined with the movement of the load in the horizontal direction. Can be calculated.

  (5) In still another embodiment of the center-of-gravity position measuring apparatus of the present invention, output means for outputting data of the center-of-gravity position calculated by the calculation means is provided.

  The output means may output the data on the center of gravity of the package as at least one of display, print, or sound, or send the data on the center of gravity to a host computer or the like via a network. It may be output. Also, the output means writes the data of the center of gravity position on an RFID tag or the like attached to the package, or prints the data of the center of gravity position as a barcode or QR code (registered trademark) attached to the package. It may be.

  The data of the center of gravity position may be the center of gravity position itself, or the amount of deviation of the center of gravity position, that is, the amount of eccentricity.

  According to this embodiment, since the data on the gravity center position of the load calculated by the calculation means is output by the output means, the operator can easily grasp the position of the gravity center of the load and consider the balance of the gravity center of the load. Thus, for example, loading work on a trailer can be performed.

  According to the present invention, since the inclination angle of the rope body and the tension applied to the rope body are detected as the cargo moves horizontally in the cargo handling work by the crane, and is used to calculate the center of gravity position of the luggage, Thus, no special operation such as tilting the load is required to determine the center of gravity position of the load. Thereby, the center-of-gravity position in the horizontal plane and the vertical plane of the load can be obtained without reducing the efficiency of the cargo handling work.

FIG. 1 is a side view of a main part of a crane including a center-of-gravity position measuring device according to an embodiment of the present invention. FIG. 2 is a schematic perspective view for explaining the lifting state of FIG. FIG. 3 is a side view corresponding to FIG. 1 when the container is moved in the horizontal direction by the crane. FIG. 4 is a block diagram of the center-of-gravity position measuring apparatus of FIG. FIG. 5 is a plan view showing the position of the center of gravity in the horizontal plane of the container. FIG. 6 is a side view for explaining the action of force when the container is moved in the horizontal direction by the crane. FIG. 7 is a side view showing the position of the center of gravity in the vertical plane of the container. FIG. 8 is a side view corresponding to FIG. 1 of another embodiment of the present invention. FIG. 9 is a schematic perspective view for explaining the lifting state of FIG. FIG. 10 is a side view corresponding to FIG. 8 for explaining the action of force. FIG. 11 is a side view corresponding to FIG. 10 when the container is moved in the horizontal direction by the crane. FIG. 12 is an enlarged view of the container before and after movement in the horizontal direction. FIG. 13 is a diagram for explaining a method of calculating the container inclination angle γ when the container is moved in the horizontal direction by the crane.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a side view showing a crane including a center-of-gravity position measuring device according to an embodiment of the present invention and a container as a load lifted by the crane, and FIG. 2 illustrates a state in which the container is lifted by the crane. FIG. 3 is a side view corresponding to FIG. 1 when the container is moved in the horizontal direction by a crane.

The crane 1 of this embodiment includes a crane main body 2, a rail 3 on which the crane main body 2 travels, and wires 4 ₁ to ₄ 4 as four cable bodies that are drawn from the crane main body 2.

In such a crane 1, the container 5 is locked by, for example, locking the lower ends of the wires 4 ₁ to ₄ 4 fed from the crane main body 2 to the four upper end corners of the rectangular parallelepiped container 5. The crane body 2 is lifted in the vertical direction and is moved along the rail 3 in the horizontal direction for transportation.

In the stationary state in which the container 5 is lifted, the wires 4 ₁ to 4 ₄ extend in the vertical direction, and the container 5 is lifted horizontally.

  In this embodiment, as shown in FIG. 1, a gravity center position measuring device 6 is provided in order to efficiently measure the gravity center position of the container 5 during the cargo handling operation of the container 5.

The centroid position measuring device 6, a pull-type load cell 7 _{1-7 4} four tension acting on each wire ₄₁ to ₄ as four load sensors which detect, the wires ₄₁ to ₄ tilt sensors 8 ₁ to 8 ₄ that respectively detect ₄ tilt angles, and based on the detection outputs of these sensors 7 _{1 to} 7 ₄ and 8 ₁ to 8 ₄ , That is, it includes an arithmetic unit 9 that calculates the position of the center of gravity in the horizontal plane (horizontal direction) and the position of the center of gravity in the vertical plane (vertical direction).

In the center-of-gravity position measuring device 6, each of the load cells 7 _{1 to} 7 ₄ is connected between the crane 1 side and the container 5 side of each wire 4 ₁ to 4 ₄ as shown in FIG. Tensile loads applied to the respective wires 4 ₁ to 4 ₄ , that is, tensions T ₁₁ , T ₁₂ , T ₂₁ , and T ₂₂ are detected. 1 and 3, the sum T ₁ (= T ₁₁ + T ₁₂ ) of the tensions T ₁₁ and T ₁₂ of the left wires 4 ₁ and 4 ₂ and the tensions T ₂₁ and T of the right wires 4 ₃ and 4 ₄ are shown. The sum T _{2 of 22} (= T ₂₁ + T ₂₂ ) is shown.

Each of the inclination sensors 8 ₁ to 8 ₄ detects an inclination angle θ of each of the wires 4 ₁ to 4 ₄ with respect to the vertical direction, and includes, for example, a gyro sensor.

When the crane body 2 is caused to travel along the rail 3 in one horizontal direction H <b> 1, for example, the wires 4 ₁ to 4 ₄ are moved between the crane body 2 and the container 5 by the inertial force acting on the container 5. As shown in FIG. 3, it is inclined at an inclination angle θ with respect to the vertical direction (z direction). Tension wire ₄₁ to ₄ is applied to each wire ₄₁ to ₄ when in the tilted state are respectively detected by the load cell 7 _{1-7 4} respectively, also the wire ₄₁ to ₄ respectively tilt angle θ is detected by each of the inclination sensors 8 ₁ to 8 ₄ .

The computing device 9 computes the position of the center of gravity in the horizontal plane of the container 5 based on the detection output of each of the load cells 7 _{1 to} 7 ₄ when the container 5 is lifted by the crane 1 and is in the stationary state shown in FIG.

Further, the arithmetic unit 9 makes the wires 4 ₁ to 4 ₄ incline as shown in FIG. 3 by the inertial force in the horizontal direction when the container 5 is moved in the horizontal direction H 1 by the crane 1. based on the detection output of the load cell 7 _{1-7 4} detection output and the tilt sensor 8 _{1-8 4} certain time, it calculates the center of gravity of the vertical plane of the container 5.

  A block configuration of the gravity center position measuring apparatus 6 having the above configuration will be described with reference to FIG. FIG. 4 is a block diagram showing in detail the configuration of the center-of-gravity position measuring device 6, and parts corresponding to those in FIGS. 1 to 3 are given the same reference numerals.

The centroid position measuring device 6, as described above, four and load cells 7 _{1-7 4,} and four tilt sensor 8 _{1-8 4,} the detection output and the inclination sensor of each load cell 7 _{1-7 4} An arithmetic unit 9 that calculates the position of the center of gravity of the container 5 based on the detection outputs 8 ₁ to 8 ₄ is provided.

Calculation device 9, the load cell 7 _{1-7 4} detection outputs an A / D converter 10 for A / D conversion respectively, respectively A / D converts the detected output of the tilt sensor 8 ₁ to 8 ₄ A / Based on the digital output from the A / D converters 10 and 11 input through the D converter 11 and the input / output (I / O) circuit 12, the center of gravity of the container 5 in the horizontal plane is described as follows. The calculation means 13 which calculates a position and the gravity center position in a vertical surface, and the display part 14 which consists of a liquid crystal display etc. which display the data of the gravity center position which is a calculation result are provided.

  The computing means 13 is constituted by, for example, a microcomputer including a CPU 15 and a memory 16.

  Next, the procedure of the calculation process of the center of gravity position by the arithmetic unit 9 of the center of gravity position measuring apparatus 6 will be described.

First, the procedure for obtaining the position of the center of gravity within the horizontal plane of the container 5 will be described. The position of the center of gravity in the horizontal plane is the tension T _{11 to} T ₄ of each wire 4 ₁ to ₄ 4 detected by each of the load cells 7 _{1 to} 7 ₄ in the stationary state shown in FIG. 1 where the container 5 is lifted by the crane 1. Calculated based on ₂₂ .

  FIG. 5 is a plan view showing the position of the center of gravity of the container 5 in the horizontal plane.

  Here, as shown in FIG. 2, the container 5 has a length in the horizontal direction (x direction) of a, a length of b in the vertical direction (y direction), and a length h in the height direction (z direction). This is modeled as a rectangular parallelepiped.

As shown in FIG. 5, the position of the center of gravity G in the horizontal plane (x _G , y _G ), that is, x when the origin is 0 at the center of a rectangle having a length in the x direction a and a length b in the y direction. The position (x _G , y _G ) in the direction and the y direction is determined by measuring the tensions T _{11 to} T ₂₂ applied to the _four wires 4 ₁ to ₄ 4 in the stationary state shown in FIGS. It can be obtained as follows.

First, the center-of-gravity position x _G in the x direction is determined by considering the moment balance about the y axis in FIG.
mg × x _G + (T ₁₁ + T ₁₂ ) × (a / 2) = (T ₂₁ + T ₂₂ ) × (a / 2)
The relationship is established.

Therefore, the barycentric position x _G in the x direction can be obtained by the following equation.

_{x G = [(a / 2} ) [(T 21 + T 22) - (T 11 + T 12)]] / mg
_{= [A [(T 21 +} T 22) - (T 11 + T 12)]] / {2 (T 11 + T 12 + T 21 + T 22)}
_{∵mg = T 11 + T 12 +} T 21 + T 22
Next, the center-of-gravity position y _{G in the} y direction is determined by considering the balance of moments about the x axis in FIG.
mg × y _G + (T ₁₁ + T ₂₁ ) × (b / 2) = (T ₁₂ + T ₂₂ ) × (b / 2)
The relationship is established.

Therefore, centroid position y _G in the y direction can be determined by the following equation.

_{y G = [(b / 2} ) [(T 12 + T 22) - (T 11 + T 21)]] / mg
_{= [B [(T 12 +} T 22) - (T 11 + T 21)]] / {2 (T 11 + T 12 + T 21 + T 22)}
Next, the principle of obtaining the position of the center of gravity in the vertical plane of the container 5 will be described based on FIGS.

6 shows that when the container 5 is moved in the horizontal direction H1 by the crane 1, the wires 4 ₁ to 4 ₄ are inclined at an inclination angle θ with respect to the vertical direction by the inertial force acting on the container 5. FIG. 7 is a side view showing the position of the center of gravity G in the vertical plane of the container 5, that is, the position e from the upper surface of the container 5. In FIG. 6, the sum T ₁ (= T ₁₁ + T ₁₂ ) of the tensions T ₁₁ and T ₁₂ of the left wires 4 ₁ and 4 ₂ and the sum T of the tensions T ₂₁ and T ₂₂ of the right wires 4 ₃ and 4 _{4 2} (= T ₂₁ + T ₂₂ ).

  From the balance of forces in the horizontal direction x,

  The relationship is established.

  Also, from the balance of moments around point Q,

  The relationship is established.

Therefore, the center of gravity position e in the vertical plane of the container 5 from the above two formulas is
e = (T ₁ acos θ−mgc) / {(T ₁ + T ₂ ) sin θ} (3)
In the above equation (3), the weight 4 of the container 5 and the gravity center position c in the horizontal direction x are calculated from the tension in the stationary state, and the wire 4 when the crane 1 moves and the container 5 is inclined by the angle θ. The center-of-gravity position e in the z direction from the upper surface of the container 5 can be measured by measuring the tensions T ₁ and T ₂ and the inclination angle θ of ₁ , 4 ₂ ; 4 ₃ , 4 ₄ .

Incidentally, the wire 4 ₁ in accordance with the movement in the horizontal direction of the container 5 by crane 1, 4 _2; 4 _3, 4 ₄ tension T _1, T ₂ and the inclination angle θ and varies, the center of gravity position e corresponding thereto Therefore, for example, the average value of the obtained centroid positions may be used as the final centroid position e, or the centroid position obtained when the inclination angle θ is maximized. It may be the center of gravity position e. Further, since the inclination angle θ is also detected by the inclination sensors 8 ₁ to 8 ₄ respectively corresponding to the wires 4 ₁ to 4 ₄ , for example, the average value thereof may be set as the inclination angle θ. Note that the inclination angle of any one of the wires may be detected by using one inclination sensor.

  According to this embodiment, the position of the center of gravity can be obtained also during acceleration / deceleration when the crane 1 moves the container 5 in the horizontal direction and when the container 5 is free vibrating.

  As described above, the arithmetic unit 9 determines the center of gravity position (horizontal center of gravity position) in the horizontal plane of the container 5 and the center of gravity position (vertical center of gravity position) in the vertical plane, that is, the three-dimensional center of gravity position. Calculate the calculation.

  In this embodiment, the calculated gravity center position in the horizontal plane and the gravity center position in the vertical plane are displayed on the display unit 14.

  Further, the arithmetic unit 9 may be connected to a printer via the I / O circuit 12 so that the data of the gravity center position can be printed out.

  As another embodiment of the present invention, the data of the gravity center position calculated by the arithmetic unit 9 is transmitted to a host computer or the like via a network, and the loading of the container 5 is performed based on the gravity center position of the container 5 by the host computer or the like. You may be made to manage.

  Further, the data of the gravity center position calculated by the arithmetic unit 9 is written to the RFID tag by the RFID writer, and the RFID tag is attached to the container 5, and the data of the gravity center position can be read from the RFID tag attached to the container 5. You may do it. Alternatively, the data of the center of gravity calculated by the arithmetic device 9 may be printed as a barcode or a QR code (registered trademark) and pasted on the container 5.

  Since the computing device 9 can calculate the weight of the container 5 as well as the center of gravity position as described above, the weight data of the container 5 may be displayed and printed in addition to the data of the center of gravity position.

  Thus, since the center of gravity position in the horizontal plane of the container 5 and the center of gravity position in the vertical plane are displayed on the display unit 14, the horizontal and vertical eccentricity states of the container 5 can be confirmed. Accordingly, for example, when the container 5 is loaded on the trailer, stable loading can be performed in consideration of the balance of the center of gravity, and safe transportation becomes possible.

(Embodiment 2)
FIG. 8 is a side view of a crane including a center-of-gravity position measuring device according to another embodiment of the present invention, and FIG. 9 is a schematic perspective view for explaining a lifted state, corresponding to the above-described embodiment. The same reference numerals are assigned to the parts to be performed.

In this embodiment, the interval of the lifting fulcrum of the wire of the crane body 2a is narrow, and in the above-described embodiment, in the stationary state where the container 5 is lifted, the wires 4 ₁ to 4 ₄ are not inclined, Although extending in the vertical direction, in this embodiment, the wires 4 ₁ to 4 ₄ are inclined while the container 5 is suspended.

Also, the lengths of the two wires 4 ₁ , 4 ₂ on the left side and the two wires 4 ₃ , 4 ₄ on the right side are different, and the left wire 4 ₁ , 4 ₂ , 4 ₂ is inclined by θ ₁ counterclockwise with respect to the vertical direction, and the right wires 4 ₃ and 4 ₄ are inclined by θ ₂ clockwise with respect to the vertical direction.

Thus, the gravity center position of the container 5 when each of the wires 4 ₁ to 4 ₄ is inclined in a stationary state in which the container 5 is lifted can be obtained as follows.

FIG. 10 is a side view corresponding to FIG. 8 showing the balance of forces. In this FIG. 10, the sum T ₁ (= T ₁₁ + T ₁₂ ) of the tensions T ₁₁ and T ₁₂ of the left wires 4 ₁ and 4 _2. And the sum T ₂ (= T ₂₁ + T ₂₂ ) of the tensions T ₂₁ and T ₂₂ of the right wires 4 ₃ and 4 ₄ is shown.

First, from the balance of forces in the z direction in a stationary state, T ₁ cos θ ₁ + T ₂ cos θ ₂ = mg (4)
From the balance of moments around point Q mgc-T ₁ acos θ ₁ = 0 (5)
From equation (5) c = T ₁ acos θ ₁ / mg (6)
FIG. 11 is a view corresponding to FIG. 10 showing a state in which the wires 4 ₁ to 4 ₄ are inclined by an inertial force when the container 5 is moved in the horizontal direction H1 by the crane 1, and FIG. It is a figure which expands and shows the model of the container 5 before and behind a movement.

In FIG. 11, θ ₁ ′ and θ ₂ ′ are inclination angles of the left wires 4 ₁ and 4 ₂ and the right wires 4 ₃ and 4 ₄ when the crane 1 is moved in the horizontal direction H1. T1 ′ and T2 ′ are the sum of the tension of the left wires 4 ₁ and 4 ₂ and the sum of the tension of the right wires 4 ₃ and 4 ₄ , and γ is relative to the horizontal direction of the container 5 at that time. It is an inclination angle.

  12, c is the position of the center of gravity in the horizontal plane with respect to the upper right side of the container 5 in a stationary state, c ′ is the position of the center of gravity in the horizontal plane with respect to the upper right side of the container 5 at the time of movement, and e is The position of the center of gravity in the vertical plane with respect to the upper right side of the container 5 in the stationary state, and e ′ is the position of the center of gravity in the vertical plane with respect to the upper right side when moving.

  In FIG. 11, from the balance of forces in the x direction,

  The relationship is established.

 From the balance of moments around point Q

  The relationship is established.

  Moreover, the following formula | equation is materialized from the geometrical relationship shown by FIG.

c = x ₁ + x ₂ (9)
x ₁ = c ′ / cos γ (10)
x ₂ = etanγ (11)
e ′ = x ₁ sin γ + (e / cos γ) (12)
Substituting equation (7) into equation (8),
(T ₂ 'sin θ ₂ ' + T ₁ 'sin θ ₁ ') e '+ mg × c'
= T ₁ 'a (cos θ ₁ ' cos γ + sin θ ₁ 'sin γ) (8')
From the formulas (9), (10) and (11) c ′ = cosγ−esinγ (13)
Substituting equation (13) into equation (8 '),
(T ₂ 'sin θ ₂ ' + T ₁ 'sin θ ₁ ') e '+ mg (ccosγ-esinγ)
= T ₁ 'a (cos θ ₁ ' cos γ + sin θ ₁ 'sin γ) (8 ")
Also, from the equations (10), (12), (13),
e ′ = (c ′ / cosγ) sinγ + (e / cosγ)
= (Ccosγ-esinγ) tanγ + (e / cosγ)
= Csin γ + ecos γ
Substituting the above equation into equation (8 ''),
_{(T 2 'sinθ 2' +} T 1 'sinθ 1') (csinγ + ecosγ) + mg (ccosγ-esinγ) = T 1 'a (cosθ 1' cosγ + sinθ 1 'sinγ)
e {(T ₂ 'sin θ ₂ ' + T ₁ 'sin θ ₁ ') cosγ-mgsinγ}
= T ₁ 'a (cos θ ₁ ' cos γ + sin θ ₁ 'sin γ) -c {(T ₂ ' sin θ ₂ '+ T ₁ ' sin θ ₁ ') sin γ + mg cos γ}
Therefore,
e = [T ₁ 'a (cos θ ₁ ' cos γ + sin θ ₁ 'sin γ) -c {(T ₂ ' sin θ ₂ '+ T ₁ ' sin θ ₁ ') sin γ + mg cos γ}] / {(T ₂ ' sin θ ₂ '+ T ₁ ' sin θ ₁ ') Cosγ-mgsinγ} (14)
From the above equation (14), the barycentric position in the vertical plane, that is, the barycentric position e in the z direction from the upper surface of the container 5 can be obtained.

  However, in order to obtain the center-of-gravity position e by the above equation (14), the inclination angle γ with respect to the horizontal direction of the container 5 is necessary.

  Therefore, a method of calculating the horizontal inclination angle γ of the container 5 necessary for calculating the gravity center position in the vertical plane will be described.

In FIG. 13 corresponding to FIG. 11, the origin O is taken as shown in the figure, the coordinates of the point P are (x _p , z _p ), the coordinates of the point Q are (x _q , z _q ), and the point P side If the length of the wire is L ₁ , the length of the wire on the point Q side is L ₂ , and the distance between the upper fulcrums is r, the coordinates of the points P and Q are as follows.

x _p = L ₁ sin (−θ ₁ ) = − L ₁ sin θ ₁
z _p = −L ₁ cos (−θ ₁ ) = − L ₁ cos θ ₁
x _q = L ₂ sin θ ₂ + r
z _q = −L ₂ cos θ ₂
From the above equation, the inclination angle γ can be expressed as follows.

tan γ = (z _q −z _p ) / (x _q −x _p )
= (L ₁ cos θ ₁ −L ₂ cos θ ₂ ) / (L ₂ sin θ ₂ + r + L ₁ sin θ ₁ )
γ = tan ⁻¹ {(L ₁ cos θ ₁ −L ₂ cos θ ₂ ) / (L ₂ sin θ ₂ + r + L ₁ sin θ ₁ )}
As described above, the inclination angle γ of the container 5 can be calculated, whereby the center-of-gravity position e in the vertical plane of the container 5 can be calculated.

  Further, the position of the center of gravity in the horizontal plane can be calculated from the balance of moments as in the above-described embodiment.

  In this embodiment, the inclination angle γ of the container 5 is calculated as described above. However, as another embodiment of the present invention, the inclination angle γ of the container 5 can be directly measured by attaching an inclination sensor to the container 5. You may do it.

(Other embodiments)
In Embodiment 2 described above, the distance between the lifting fulcrums of the wire of the crane body 2a is narrow, but the present invention can be similarly applied to the case where the distance between the lifting fulcrums of the crane body 2a is wide. Is.

The load cell, since there is provided with an inclination sensor, may be omitted tilt sensor 8 _{1-8 4} using such load cells.

  In each of the above-described embodiments, description has been made by applying to the container 5 as a package, but the present invention is not limited to the container but can be applied to various articles conveyed by a crane.

In each of the above-described embodiments, the load is lifted by the _four wires 4 ₁ to 4 ₄ , but may be lifted by at least two wires or chains. Further, the luggage may be lifted by three or five or more wires.

  The present invention is useful for measuring the position of the center of gravity of a load carried by a crane.

1 Crane 3 Rail 4 ₁ to 4 ₄ Wire 5 Container 6 Center of Gravity Position Measurement Device 7 _{1 to} 7 ₄ Load Cell 8 ₁ to 8 ₄ Tilt Sensor 9 Arithmetic Unit

Claims (5)

A gravity center position measuring device that measures the gravity center position of the load of a crane that lifts and loads a load by a plurality of ropes and moves it horizontally.
A load sensor for detecting each tension acting on each of the plurality of cords;
An inclination sensor for detecting an inclination angle of the cable body accompanying the movement in the horizontal direction;
Based on detection outputs of the load sensor and the tilt sensor, calculation means for calculating each gravity center position in a horizontal plane and a vertical plane of the luggage,
A center-of-gravity position measuring device comprising: The crane lifts the load by at least four ropes,
The load sensor is provided for each cord body, and each tension acting on each cord body is detected.
The center-of-gravity position measuring apparatus according to claim 1. The computing means computes the position of the center of gravity in the horizontal plane of the load based on the detection output of the load sensor in the state where the load is lifted, and the rope body is inclined with the movement in the horizontal direction Based on the detection output of the load sensor and the tilt sensor in the calculation of the center of gravity position in the vertical plane of the luggage,
The center-of-gravity position measuring device according to claim 1 or 2. The computing means computes the position of the center of gravity of the load in a horizontal plane based on the detection output of the load sensor and the tilt sensor in a state where the load is lifted and the rope body is inclined, and moves in the horizontal direction. And calculating the position of the center of gravity in the vertical plane of the load based on the detection output of the load sensor and the tilt sensor in a state in which the cord body is tilted.
The center-of-gravity position measuring device according to claim 1 or 2. Output means for outputting the data of the center of gravity calculated by the calculating means;
The center-of-gravity position measuring device according to any one of claims 1 to 4.

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