JPS6245156B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a method for lifting one load together using two or more cranes, such as jib cranes, deck cranes, twin cranes, etc., each having a turning function and an elevating function. Crane (hereinafter referred to as main crane)
The present invention relates to a co-suspension control method in which the other crane (hereinafter referred to as a slave crane) follows the movement of the crane so as to satisfy predetermined geometrical conditions between both crane booms.

Generally, in cargo handling facilities that use cranes as a means of moving cargo, the lifting capacity of each crane is limited.
In order to increase the capacity of the cargo handling facility, multiple cargoes, especially two cranes, can be used to simultaneously lift one cargo.
Both cranes may be operated in coordination. At this time, the crane used is a jib crane,
In the case of so-called swing-type cranes such as deck cranes, in order to move both crane booms in the same direction, the desired direction must be separated into the crane's swing direction and the crane's elevation direction. However, even if the desired direction of movement is the same, the distribution of the rotation and elevation movements changes from moment to moment as the boom moves. Therefore, as mentioned above, when multiple cranes are used to lift a single load, if the cranes used are swing type cranes, multiple people must each operate one crane, even if one person operates multiple cranes. Regardless of the operation, it is very difficult to move all cranes in the same direction using a common coordinate system, which can lead to poor cargo handling efficiency, collisions between crane booms, and suspension lines. There is a high risk of causing breakage accidents.

Therefore, there is a need to automate crane operation in such a way that when one person operates the main crane, other slave cranes automatically follow the movement, and there are already efforts being made to automate crane operations in accordance with the concept of automation. Several co-suspension control methods exist that automatically generate signals to be applied to the drives of cranes (slave cranes) other than the human-operated crane (main crane) according to certain algorithms. However, the reality is that all of these existing methods have drawbacks, such as complicated calculations, non-negligible calculation errors, and the need for a large number of detectors.

In some existing methods, the positional deviation of the secondary crane boom from the geometrical conditions that would exist between the main and secondary crane booms when co-suspension is ideally performed is calculated in each axis direction of a Cartesian coordinate system fixed to the ground. Control is performed by converting the detected components into components in the rotation direction and elevation direction of the slave crane, and applying them to the respective drive systems of the slave cranes. In this method, the absolute positions of the master and slave cranes in the above coordinate system are first determined, and then the difference between the two absolute positions is determined to determine the deviation of the slave crane from the above geometric conditions. In a normal crane system, the allowable deviation is small compared to the absolute position coordinates, so
Even if the relative error in determining the absolute position is minute, it may no longer even be possible to determine whether or not a shift actually exists.

In addition, in other conventional methods, first the position where the slave crane boom should be if ideally co-suspended is determined from the swing angle and the elevation angle, and then a signal is generated corresponding to the difference between this and the actual position. Co-suspension control is performed by applying this to the rotation and elevation drive system of the subordinate crane. In this method, the actual situation is that the calculation contents are quite complicated, such as the need to calculate the square root when determining the desired position of the slave crane mentioned above.

The present invention aims to provide a co-suspension control method that overcomes the above-mentioned drawbacks. Hereinafter, the present invention will be specifically explained using the drawings.

FIG. 1 is a diagram showing a co-hanging situation. In Figure 1, 1 is the main crane boom, 2 is the secondary crane boom, 3 is a suspended load such as a container, 4 and 5
represents a hanging cable. The lengths of the main and slave crane booms 1 and 2 are R, the distance between the rotation axes of the main and slave cranes is L, the swing angles of the main crane and slave crane are θ ₁ and θ ₂ respectively, and the booms of the main crane and slave crane are The angle of elevation formed by ψ ₁ and
Let ψ be ₂ . Then, let the horizontal plane be π, and on the plane π, the intersection of the plane π and the rotation axis of the slave crane is the origin 0, and the straight line passing through the origin 0 and connecting both rotation axes is the x axis,
Cartesian coordinate system 0-xy with the y-axis being a straight line perpendicular to the axis
Take. The points where the hanging cables 4 and 5 are connected on the booms 1 and 2 of the main crane and the slave crane are orthogonally projected onto the plane π, respectively, are P ₁ and P ₂ , and the points P 1 and P ₂ in the coordinate system 0-xy are respectively Letting the coordinates of P ₂ be (x ₁ , y ₁ ) and (x ₂ , y ₂ ), respectively, The following formula holds true. However, θ ₁ and θ ₂ are measured counterclockwise with the x-axis as a reference.

The aforementioned geometrical conditions are the orthogonal projections P ₁ and P ₂ of the hanging cable connection points of the main and secondary cranes onto the plane π.
It refers to the conditions established between
It is expressed that P ₂ coincides with point ₂ defined by the position of P ₁ .

Normally, when co-hanging, (a) keeping the hanging cable vertical, (b) moving the suspended load in parallel,
These two points are added as requirements for crane operation. Therefore, in this case, ₂ is the point obtained by translating P ₁ . Expressing this condition in a formula using the 0-xy coordinate system, if the coordinates of ₂ are ( ₂ , ₂ ), then It is given by the formula. Here, A and B are constants. Therefore, while observing P ₁ and P ₂ from time to time,
Co-suspension control can be performed by determining P ₂ from the position of P ₁ and giving the deviation between P ₂ and ₂ as a drive signal to the drive system of the slave crane.

A feature of the present invention is that the deviation between P ₂ and ₂ is detected using a rectangular coordinate system fixed to the slave crane itself, and the components in the direction of each coordinate axis are given as drive signals to the elevation drive system and swing drive system of the slave crane. It is in.

FIG. 2 is a diagram illustrating a method for detecting a deviation from the geometrical condition of a slave crane according to the present invention;
It represents a part of the plane π in FIG.
In Fig. 2, 6 is the orthogonal projection of the slave crane boom 2 onto the plane π, point _P2 is the orthogonal projection of the connection point between the slave crane boom 2 and the suspension cable 5 onto the plane π, and ₂ is the main crane boom. The coordinate point to be occupied is P ₂ when the predetermined geometric condition is satisfied for . That is, FIG. 2 shows a state when the slave crane does not satisfy the predetermined geometrical conditions.

In Fig. 2, the straight line including the orthogonal projection 6 of the slave crane boom 2 onto the plane π on the plane π is the X axis, 0
- A straight line passing through the origin of the xy coordinate system and perpendicular to the X axis is
Take the orthogonal coordinate system 0-XY as the axis. In the present invention, this coordinate system 0-XY is a rectangular coordinate system fixed to the slave crane itself, and the X-axis direction corresponds to the elevation direction of the slave crane, and the Y-axis direction corresponds to the rotation direction of the slave crane. do. If the coordinates of point P ₂ and point ₂ in the 0-XY coordinate system are (X ₂ , 0) and ( ₂ , ₂ ), respectively, then the deviation of P ₂ from the geometric condition can be expressed in the 0-XY coordinate system as ba( ₂ -
X ₂ , ₂ ). That is, the method according to the present invention basically provides _{a 2} -X ₂ drive signal to the drive system for elevating and raising the slave crane, and a drive signal of ₂ to the drive system for swinging, and sends a signal between the main and slave crane booms. The slave crane is controlled so that predetermined geometric conditions are met.

By the way, as mentioned above, the deviation of the slave crane is set to 0.
- When using each coordinate axis component of the XY coordinate system as a drive signal, ( ₂ -X ₂ ,
₂ ) are the same, the larger 0P _{2 =}
The smaller 0 _{2 =} It will differ depending on the position occupied. Therefore, when implementing the method of the present invention, it is preferable to make appropriate corrections in order to obtain an appropriate drive signal in accordance with the amount of rotation and elevation, regardless of the position of the slave crane. One method for this correction is to provide ₂ /X ₂ or _2/2 as _a drive signal for the turning direction. It is clear from FIG. 2 that this method has a corrective effect. Also, regarding the elevation direction, ( ₂ - X ₂ )/Rsinψ ₂
There is a method of giving it as a driving signal. It is clear from FIG. 2 that this method also has a correction effect. _{In other words ,} if _{we set} ψ _{2 = cos} ^-1 Since there is a relationship of ψ ₂ - ψ ₂ /2/sin ψ ₂ , if ψ ₂ - ψ ₂ is small, the drive signal in the elevation direction will hardly be affected by the position of the slave crane, and will be approximately the same as the amount to be elevated. It will be a proportional value. It goes without saying that various methods other than those described above can be considered as methods for correcting this drive signal.

Next, a specific example of a co-suspension control system implementing the present invention will be described with reference to FIGS. 3 and 4. Here, the coordinates of ₂ are given by equation (3) above, and the driving signal is changed in the turning direction according to the correction method described above.
₂ /X ₂ , and the elevation direction shall be corrected to ( ₂ - X ₂ )/Rsinψ ₂ . Under such conditions, 0-
Since the XY coordinate system is a coordinate system obtained by rotating the 0-xy coordinate system counterclockwise by θ ₂ , generally,
If one point P has coordinates (x, y) in the 0-xy coordinate system and (X, Y) in the 0-XY coordinate system, then (x, y)
The following relationship holds between and (X, Y): X=x cos θ ₂ +y sin θ ₂ Y=−x sin θ ₂ +y cos θ ₂ . Therefore, becomes. On the other hand, according to equations (1) and (3), ₂ and ₂ are is given by

In addition, the drive signal for the rotation of the slave crane is
θ, and let the drive signal for elevation and elevation be uθ, then becomes.

Now, looking at equations (4), (5), and (6), it can be seen that the drive signal is derived from the sine and cosine functions of the turning and elevation angles of both the main and secondary cranes using only four arithmetic operations. An existing method, for example, calculates the desired position of the slave crane in the case of ideal co-suspension using the turning angle and elevation angle, and uses the signal of the difference from the actual value to correspond to the rotation and elevation of the slave crane. Compared to a method that requires a square root calculation, such as a method of performing co-suspension control by applying a signal to a drive system, the calculation of the method of the present invention is simpler. Furthermore, when uθ and uψ are written using the turning and elevation angles of the main and secondary cranes, uθ={−(cosψ ₁ cosθ ₁ +A−L/R) sinθ ₂ + (cosψ ₁ sinθ ₁ +B/R) cosθ ₂ }/cosψ ₂ uψ={(cosψ ₁ cosθ ₁ +A−L/R) cosθ ₂ + (cosψ ₁ sinθ ₁ +B/R) sinθ ₂ −cosψ ₂ }/sinψ ₂ . As is clear from this equation, when compared with other existing methods, that is, first determining the absolute position using the 0-xy coordinate system, and then determining the deviation from the geometric conditions based on the difference in absolute positions, the present invention can provide a method with fewer calculation errors such as loss of digits.

The calculations of these equations (4), (5), and (6) are cosθ ₁ , sinθ
₁ , cosψ ₁ , cosθ ₂ , sinθ ₂ , cosψ ₂ , sin
It becomes executable if ψ ₂ and each constant are given. That is, in one embodiment of the invention described herein, the swing and elevation angles of the master crane and slave crane are detected in the form of sine and cosine functions;
(5) Perform calculations of equations (4) and (6) to obtain uθ, uψ
is given to the slave crane's drive system as a drive signal.

FIG. 3 shows a block diagram of an example of a system for carrying out the above-described co-suspension control method of the present invention. Third
In the figure, 7 and 8 are mechanisms for detecting the turning angle and elevation angle of the main crane in the form of sine and cosine functions, respectively, and 9 and 10 are mechanisms for detecting the turning angle and elevation angle of the slave crane in the form of sine and cosine functions, respectively. 11 and 12 are movement mechanisms for the main crane and the slave crane, respectively; 13 and 14 are drive devices for turning and elevating the slave crane, respectively;
Reference numeral 15 denotes an arithmetic device having a function of executing the arithmetic operations of equations (5), (4), and (6). In this system, the detection mechanism 7,
8, 9, and 10 as sine and cosine functions are input, and the arithmetic unit 15 calculates equations (5), (4), and (6). Perform calculations to calculate drive signals uθ and uψ for the slave crane, and use these to control the rotation and rotation of the slave crane.
Input to drive devices 13, 14 for elevation. The detection mechanisms 7, 8, 9, 10 are potentiometers,
This can be easily realized using an existing device such as a synchronizer, and the drive devices 13 and 14 can also be easily realized using a combination of an existing electro-hydraulic servo mechanism and a hydraulic winch. Further, the arithmetic unit of block 15 can also be easily realized by a combination of electronic arithmetic units and the like.

FIG. 4 shows a specific example of the arithmetic unit 15 realized by an analog electronic circuit. In Figure 4, 16,
17, 20, 21, 22, 23 are multipliers, 18,
19, 24 are adders, 25, 26 are subtracters, 2
7 and 28 are dividers. Input signals to the arithmetic unit 15 are sent to the detection mechanisms 7, 8, 9, 10 in FIG.
Signals of the sine and cosine functions of the swing angle and elevation angle of the main and secondary cranes given by cosθ ₁ , sinθ
₁ , cosψ ₁ , cosθ ₂ , sinθ ₂ , cosψ ₂ , sin
These are constant value signals (A-L)/R and B/R set by ψ ₂ and potentiometers. These signals pass through the circuit and are used as a drive signal uθ for the drive device 13 for turning the slave crane in FIG. 3, and a drive signal uψ for the drive device 14 for raising and lowering the slave crane in FIG.

Although FIG. 4 shows an arithmetic unit 15 configured to perform calculations of equations (4), (5), and (6) using an analog electronic circuit, the calculation unit 15, including the detection section and the drive section, uses a digital calculation circuit. Of course, processing is also possible.

As is clear from the above description, according to the present invention, it is possible to automate the control of co-suspension work, which conventionally required a high level of skill and was accompanied by dangers such as cable breakage and boom collision. Furthermore, since calculations in the control system can be executed more easily and with higher precision than in the past, the control system can also be simplified.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a co-suspension situation, Fig. 2 is a diagram for explaining the principle of the present invention, Fig. 3 is a block diagram showing an example of a control system implementing the present invention, and Fig. FIG. 4 is a circuit diagram showing an example of the arithmetic device shown in FIG. 3; 1... Main crane boom, 2... Subordinate crane boom, 3... Hanging load, 4, 5... Hanging cable, π
...Horizontal plane, 6... Orthogonal projection of the slave crane onto the plane π, 7... Main crane turning angle detection mechanism, 8... Main crane depression/elevation angle detection mechanism, 9... Slave crane turning angle detection mechanism, 10... Slave crane elevation angle detection mechanism, 11...Main crane movement mechanism, 12...Slave crane movement mechanism, 13...Slave crane rotation drive device, 14...Slave crane elevation drive device, 15...
Arithmetic device, 16, 17, 20, 21, 22, 23
... Multiplier, 18, 19, 24 ... Adder, 2
5, 26... Subtractor, 27, 28... Divider, P ₁
... Orthogonal projection of the main crane suspension cable connection point onto the plane π, P ₂ ... Orthogonal projection of the slave crane suspension cable connection point onto the plane π, ₂ ... P ₂ when the geometric conditions are satisfied
The point that should be occupied.

Claims (1)

[Claims] 1 The rotation angle and elevation angle of the slave crane boom are controlled to follow the main crane boom so that the relative positions between the booms of the master and slave cranes satisfy predetermined geometric conditions, In a system in which the main crane boom is co-suspended, the deviation between the position of the slave crane boom that satisfies the above geometrical conditions and the actual position of the slave crane boom relative to the main crane boom is calculated as follows: The orthogonal projection is detected as a component in each coordinate axis direction of a rectangular coordinate system in a horizontal plane with the X axis and the direction perpendicular to it as the Y axis, and the elevation angle of the slave crane is controlled so that the deviation in the X axis direction is zero. and controlling the turning angle of the slave crane so that the deviation in the Y-axis direction is zero.