EP3293141A1 - Operating method for a crane installation, especially for a container crane - Google Patents

Abstract

A crane system, in particular a container crane, comprises a cat (4) for transporting a load (6). The load to be transported (6) determines a loading of the cat (4). The crane system has a travel drive (8) connected to the cat (4) and a cat control (28) connected to the travel drive (8) for controlling movement movements of the cat (4). The cat control (28) controls acceleration and braking during the movement of movement of the cat (4) as a function of the loading of the cat (4) and the maximum available driving force of the travel drive (8).

Description

The present invention relates to an operating method for a crane installation, in particular for a container crane, with a cat for transporting a load, wherein the load to be transported determines a loading of the cat, a travel drive connected to the cat and a carriage control connected to the travel drive for controlling Traversing motions of the cat.

The present invention further relates to a computer program comprising machine code executable by a cat controller, wherein the processing of the machine code by the cat controller causes the cat controller to control traversing movement of the cat.

Crane systems are known to serve the handling of goods, in particular container crane systems are used to move or transport large containers, which are for example between 20 feet and 48 feet long. Typical sizes are 20 feet, 40 feet and 48 feet. One foot corresponds to 12 inches and thus 30.48 cm. Container crane systems are used, for example, for loading and unloading ships or railway wagons, etc. Such a crane system generally has a horizontally movable cat on which a load handling device, so for example, a container harness or a container spreader hangs, via which the load to be moved is gripped. Container handling mainly takes place via the cat movement.

The loading and unloading of container ships takes place in manned container bridges by a crane driver who sits in a cabin, which is usually attached to the cat. In manned gantry cranes accelerations and also changes in acceleration (ie the jerk) during the Container handling limited, so that the traveling crane operator physically not unduly stressed by occurring acceleration forces and is not impaired in his well-being.

Thus, in the case of manned container bridges, the travel drive of the cat is designed for a defined acceleration (for example 0.6 m / s ² ) at a maximum load or maximum load to be transported. For example, maximum load means a total mass in the range of 110 t, which must be moved. This total mass is composed, for example, as follows: Mass of the cat: about 25-30 t Mass of the headblock: about 5-10 t Mass of the spreader: about 10-15 t Max. Container mass, two 20ft containers, fully loaded: about 60 t

Accelerations and braking during the movements of the cat thus take place with the once defined acceleration of, for example, 0.6 m / s ² . This also applies if a lower than the maximum load is to be handled.

New gantry cranes are being equipped more and more without a crane cab and are being operated automatically. For picking up and setting down the load in the destination position, the container bridges are usually controlled via a remote control desk. This allows automatic operation of the container bridge. The target positions for loading and unloading to be approached are communicated to the crane control via loading orders.

The object of the present invention is to provide an operating method for a crane system, which in particular in the automatic crane operation in comparison to previously known operating method faster cargo handling is possible.

The object is achieved by an operating method having the features of patent claim 1. Advantageous embodiments of the operating method are the subject of the dependent claims 2 to 10.

According to the operating method specified above is configured in that the cat control controls acceleration and braking during the movement of the cat as a function of the loading of the cat and the maximum available driving force. This leads to time optimal driving curves, because during all acceleration and braking in the driving curves always the maximum driving force of the travel drive can be used.

This operating method leads to a time-optimized transport of goods, especially in the case of automatic operation of the crane system. The invention is based on the recognition that the masses to be moved can change considerably in the individual traversing processes. For example, one container may have a mass of 25 tons, another container a mass of 10 tons. In addition, there are still so-called empty trips, so trips without a container on the load-carrying means. Thus, other conditions for a time-optimized container handling apply to the automatic operation than for the semi-automatic operation with a traveling crane operator, where the resulting high acceleration values would not be possible under reduced load due to the limited physical capacity of the crane operator.

The occurring differences in mass arise on the one hand by the variation of the freight in the containers, on the other hand also by different container types and sizes, so that the empty mass alone can change from container to container.

In addition, with different spreader types, which also vary with their spreader mass, a different number of containers with different design and size can be transported. So it is a great variety of container transport possible, which is always a different mass transported.

The masses that remain constant are the mass of the cat itself and the mass of the headblock. Everything else can vary.

An example is intended to illustrate the time savings made possible by the invention. When unloading a container ship, e.g. a double container brought from the ship ashore. On the way back to the ship then usually no container is transported for logistics reasons. In this so-called empty drive, the mass of headblock plus spreader to be moved is, for example, 20 t. Together with the cat, the total mass is then for example 50 t, which represents about half of the maximum load of 110 t. As a result, by taking advantage of the available driving force, it would be possible to drive at slightly more than twice the acceleration on these empty runs. When transporting only a 20-foot container from the ship on land, you would have about 25% less total mass, so in this case could be driven with 25% more acceleration than with maximum load.

Since the trend is increasingly towards cable-drawn cats, there is nothing to prevent an increase in the cat acceleration, because with such a travel drive there is basically no limit to the acceleration due to the wheel-rail friction.

An advantageous embodiment of the operating method is given by the features of claim 2. After that, the load of the cat is detected with a load measuring device connected to the cat and the load. This is the cat control Immediately and at any time the current load for the specification and control of the movement available.

A particularly advantageous embodiment of the operating method is given by the features of claim 6. Thereafter, the cat control controls the movement such that oscillations of the load when reaching a target position are compensated. Thus, the time required for the goods handling is further reduced because waiting times due to Ausstoßelungen omitted. A pendulum control for damping the pendulum motion must therefore only disturb disturbances, such as the wind pressure. This allows a much faster positioning compared to conventional operation. In conventional operation, the sway control operates throughout the travel. In conventional operation, there is no separation of guiding and disturbing behavior, so that it can compensate for oscillations even when the crane driver makes manual intervention on the travel speed (changes in the reference variable).

A further, particularly advantageous embodiment of the operating method is given by the features of claim 8. Thereafter, the travel drive comprises at least one electric motor, and the at least one electric motor is operated during the movement in at least two different operating points. This is possible with the goal of the highest possible speed cascading of several different time-optimized driving curves, especially for long travels. During acceleration, the engine is operated at its first operating point until a first maximum speed is reached. Then the engine is operated at a second operating point characterized by a second maximum speed. The second maximum speed is higher than the first maximum speed. This increased maximum speed is then used in the constant speed range. For very long travels, a multiple cascading of several operating points is possible, whereby the operating points through each distinguish higher speeds at lower torque.

The object is further achieved by a computer program having the features of claim 11. According to the invention, a computer program is designed in such a way that the processing of the machine code by the cat control causes the cat control to accept a loading of a cat controlled by the cat control and acceleration and braking during the movement of the cat as a function of the loading of the cat and the maximum Available driving force of the traversing drive controls.

FIG 1

in einer Übersichtsdarstellung einen Ausschnitt einer Containerkrananlage mit einer Laufkatze und einer dazugehörigen Katzsteuerung,

FIG 2

in einem Diagramm die Abhängigkeit der lastabhängigen maximalen Beschleunigung der bewegten Masse,

FIG 3

in einem Zeitdiagramm verschiedene Geschwindigkeitsprofile bei unterschiedlicher Beladung,

FIG 4

in einem Diagramm eine Motorkennlinie eines Elektromotors mit zwei verschiedenen Arbeitspunkten,

FIG 5

ein Geschwindigkeitsprofil einer Verfahrbewegung mit einem Elektromotor, der während der Verfahrbewegung in zwei verschiedenen Arbeitspunkten betrieben wird, und

FIG 6

die zu dem Geschwindigkeitsprofil nach FIG 5 gehörenden Beschleunigungswerte.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the exemplary embodiments, which will be described in more detail in conjunction with the drawings. Here are shown in a schematic representation:

FIG. 1

an overview of a section of a container crane system with a trolley and an associated cat control,

FIG. 2

in a diagram the dependence of the load-dependent maximum acceleration of the moving mass,

FIG. 3

in a time diagram different speed profiles at different loading,

FIG. 4

in a diagram a motor characteristic of an electric motor with two different operating points,

FIG. 5

a speed profile of a movement with an electric motor, which is operated during the movement movement in two different operating points, and

FIG. 6

to the speed profile FIG. 5 belonging acceleration values.

FIG. 1 shows a section of a container crane system, as used, for example, for loading and unloading a ship lying on a quay, with a horizontally oriented boom 2. On the boom 2 is a trolley 4 - hereinafter only cat 4 - led to turn a load , The load may be in the form of one or two containers 6, for example. The cat 4 is connected to a travel drive 8. This is preferably a cable-guided travel drive 8 with two electric motors 10. The two electric motors 10 are mechanically connected, for example, via a respective cable drive 12 in the direction of movement opposite the cat 4. The cat 4 runs on the boom 2 on rollers or wheels 14. Cable-guided travel drives 8 allow high acceleration values, which are not limited by a static friction value between the rollers 14 and a rail guide of the boom 2.

In the cat 4 a hoist (not shown here) for raising and lowering the load to be transported 6 is arranged. The hoist comprises hoisting ropes 16, which are fastened by their ends to a head block 18. The head block 18 connects a spreader 20 with the hoist. The spreader 20 takes the load 6 for transport.

The cat 4 thus allows about the hoist vertical movements of the load 6 in the direction of the double arrow 22 and on the electric motors 10 horizontal movements of the load 6 in the Katzrichtung (double arrow 24).

The hoist of the cat 4 comprises at least one load measuring device 26, according to FIG. 1 two load-measuring devices 26. The load-measuring devices 26 can be realized with various technologies, such as, for example, as ring force transducers, load measuring axes, pressure force transducers or also load measuring pins. In the present embodiment, the load measuring devices 26 are designed as ring force transducers, which are arranged at the rope end points of the hoisting ropes 16.

As a "measuring washer" they simultaneously serve for load detection and overload protection.

The currently transported load 6 on the trolley 4 is detected by the load measuring devices 26 and given to a cat control 28. The cat control 28 determines control signals for the travel drive 8 from the current load values, as will be described in detail below. The cat controller 28 is usually designed as a software programmable device. Its operation is determined in this case by a computer program with which the cat control 28 is programmed. The computer program comprises machine code that can be processed by the cat control 28. The processing of the machine code by the cat control causes the operation of the crane system explained in more detail below.

The crane system is equipped for automatic operation, which allows a target for the cat movements. It is therefore not necessary that the cat 4 has a crane cab. Instead, the cat has 4 sensors for detecting the position of the load to be transported 6, the measurement signals of the cat control 28 for automatic control of the travel paths of the cat 4 are supplied. The picking up and setting down of the load is carried out via a remote control desk 30 which allows the remote control of the cat movement.

The cat control 28 determines from the current value of the load m _{load_akt} a loading _factor K _{load of} the crane. The load _factor K _load is defined by the ratio of the current load _{m_last_akt} to the maximum possible load _{m_max of} the crane on the basis of the drive design, ie the rated load or rated load. So expressed as a formula $${\mathrm{K}}_{\mathrm{load}}={\mathrm{m}}_{\mathrm{Last\_akt}}/{\mathrm{m}}_{\mathrm{LAST\_MAX}}$$

The value of the loading factor K _Last is always less than or equal to "One".

For the rated load or rated load of the crane, which is designed for the maximum load _{m_max} , a maximum acceleration _{value a_max_nominal} determined by the nominal drive force of the travel drive 8 shall be used with the speed changes within the travel of the cat 4.

The inventive concept realized in the cat control 28 is now to increase the acceleration a _{max_nom} to the value a _{max_adapt} at a lower load of the crane than the nominal load m _{Load_max} (K _load <1), as permitted by the rated drive force of the travel drive 8. The factor for increasing the acceleration is the reciprocal of the loading factor: $${\mathrm{K}}_{\mathrm{Besch}\mathrm{1}}=\mathrm{1}/{\mathrm{K}}_{\mathrm{load}}$$

Thus, the current maximum possible acceleration at a loading of the crane, which is smaller than the nominal load, increased accordingly: $${\mathrm{a}}_{\mathrm{max\_adapt}}={\mathrm{a}}_{\mathrm{max\_nenn}}*{\mathrm{K}}_{\mathrm{Accel}}={\mathrm{a}}_{\mathrm{max\_nenn}}/{\mathrm{K}}_{\mathrm{load}}$$

With the modification of the maximum acceleration a _{max_nom} by the loading _factor K _load or the acceleration _factor K _detk , it is achieved that the maximum possible acceleration a _{max_adapt is always} traveled for each traversing process independently of the load to be transported.

FIG. 2 shows the relationship described above between the size of the moving mass and the load-dependent acceleration a _{max_akt} . In this case, the load-dependent acceleration a _{max_akt is plotted} on the abscissa axis and the size of the moved mass is plotted on the ordinate axis. The moving mass results from the sum of fixed mass of cat 4, head block 18 with hoisting ropes 16 and spreader 20 plus the variable mass, for example in the form of the container to be transported 6. At maximum moving mass of the drive 8 can cause the maximum acceleration a _{max_nom} . This operating state BP1 is indicated in the diagram by the upper beginning of a working line 34. The maximum possible acceleration during an empty _travel a _{max_leer_} , ie only the fixed moving mass without a load to be transported, is indicated by the operating point BP 2 at the lower end point. Between these two operating points BP1 and BP2, a higher acceleration a _{max_adapt can be} driven in accordance with the magnitude of the reduced load in relation to the maximum load. The higher acceleration a _{max_adapt} lies between the maximum acceleration a _{max_nom} with full load and the maximum acceleration with an empty _drive a _{max_leer} , see in the diagram the operating range 38 on the abscissa axis.

FIG. 3 In comparison, simplified shows three typical speed profiles 40, 42, 44 of the cat 4 at a given trajectory, resulting in the automatic operation of the crane at different load conditions. On the one hand, this means that the load-dependent, maximum possible acceleration a _{max_adapt} already explained above is used to _{build up} the speed and to decelerate, and on the other hand, the load oscillation or load oscillation in the travel curve is taken into account. The speed profile 40 is obtained when loading the crane with maximum load, the speed profile 42 results with a partial load of the crane, and the speed profile 44 results in an empty run of the cat. 4

It is typical for all three velocity profiles 40, 42, 44 that after a velocity increase up to a first maximum velocity 46 (local maximum) but lower than the maximum possible velocity v _max at all, a velocity reduction to a local minimum 48 follows again a maximum possible increase in speed with a _{max followed} by the maximum possible speed v _max . This is symmetrical Speed profile in the braking phase or in the braked section of the travel movement to the target position. The speed changes are designed so that the oscillation of the load is calmed down at least in the target position and preferably also when the maximum speed v _max is reached.

The speed profile 40 is also adjusted in conventional cranes when only a partial load is present or even a run is performed. In contrast, in the present invention at a lower load, the acceleration is increased so much that the maximum motor drive force is used for acceleration. Thus, by applying the present invention to a conventional cat control in the case of a partial loading, there is a gain in time which, in the case of empty travel, is at most equal to the quantity Δt _amax .

As is known, in various electric motors, such as synchronous motors, asynchronous motors, direct current motors, etc. can achieve an increase in the rated speed by reducing the magnetic flux of the field winding. This workspace is also referred to as field weakening area. FIG. 4 shows the typical course of a motor characteristic M (n), which shows the generated torque M as a function of the rotational speed n, with a first operating point AP1 in normal field operation and a second operating point AP2 in the field weakening operation. At the operating point AP1, a moment M ₁ is generated at a speed n ₁ and a moment M _{2 is} generated at the operating point AP ₂ at a speed n ₂ . Although the generated torque is reduced at the operating point AP2, the speed is simultaneously increased.

The use of electric motors and their operation in the field weakening area makes it possible to further increase the time savings in the handling of goods, in particular with long travel distances of the cat 4. This is in FIG. 5 typically shown. Longer travel distances can then with a constant, increased Be driven speed. With an electromotive traction drive without field weakening operation or without the use of the field weakening operation, for example, a speed profile 50 can be realized in which a maximum traversing speed v ₁ can be achieved with the drive torque M ₁ . Another time gain in goods handling can now be achieved if, when approaching the nominal speed n ₁ at the operating point AP _1, the operating point AP 2 of the field weakening operation is changed. Then, although the drive torque M _{2 is} reduced, the maximum travel speed v ₂ is further increased. Similarly, during braking when the travel speed v _{1 is reached} , it is changed back to the operating point AP1. This relationship is illustrated with the velocity profile 52. In FIG. 5 also the time gain Δt _vmax achievable by the field weakening operation is shown.

The acceleration profiles associated with the velocity profiles 50 and 52 are shown FIG. 6 , Due to the higher available drive torque M ₁ in normal operation, an acceleration value of a ₁ can be achieved. The achievable acceleration value a ₂ in the field weakening operation is lower than in normal operation.

For very long travel distances can be achieved by further cascading of operating points in field weakening a further increased final speed and thus a further time gain in freight transport.

The present invention has many advantages. In particular, there is a higher turnover.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims (12)

Operating method for a crane installation, in particular for a container crane, with a cat (4) for transporting a load (6), wherein the load (6) to be transported determines a loading of the cat (4), a travel drive connected to the cat (4) (8) and a carriage control (28) connected to the travel drive (8) for controlling travel movements of the cat (4),
characterized in that the cat control (28) controls acceleration and braking during the movement of movement of the cat (4) as a function of the loading of the cat (4) and the maximum available driving force of the travel drive (8). Operating method according to claim 1,
characterized in that the loading of the cat (4) is detected by a load measuring device (26) connected to the cat (4). Operating method according to claim 1 or 2,
characterized in that the movement of movement of the cat (4) comprises at least one accelerated and a braked section and that the positive and / or negative acceleration of the movement takes place as a function of the load. Operating method according to one of the preceding claims,
characterized in that a maximum possible acceleration of the movement is determined by the maximum driving force associated with the cat (4) traverse drive (8) and a minimum loading of the cat (4). Operating method according to one of the preceding claims,
characterized in that a maximum acceleration (a _{max_nom} ) of the movement of movement by the maximum driving force of the cat (4) connected Verfahrantriebs (8) and a maximum load m _{LAST_MAX} is determined and that m at a current load _{Last_akt} the maximum acceleration a _{max_adapt} from the maximum acceleration at maximum load a _{max_nenn} by a factor K _Acc is increased, where K _Accel = m _{LAST_MAX} / m _{Last_akt} and M _{Last_akt} <m _{Last_max} . Operating method according to one of the preceding claims,
characterized in that oscillations of the load (6) are compensated when reaching a target position. Operating method according to one of the preceding claims,
characterized in that oscillations of the load (6) are compensated when reaching a maximum travel speed. Operating method according to one of the preceding claims,
characterized in that the travel drive (8) comprises at least one electric motor (10) and that the at least one electric motor (10) during the movement in at least two different operating points (AP1, AP2) is operated. Operating method according to claim 8,
characterized in that at least one of the operating points (AP2) is in the field weakening range of the at least one electric motor (10). Operating method according to claim 9,
characterized in that the at least one electric motor (10) is operated after reaching a rated speed (n ₁ ) to increase the speed of the movement in the field weakening range. A computer program comprising machine code executable by a cat controller (28), wherein the processing of the machine code by the cat controller (28) causes the cat control (28) receives a load of a cat (4) controlled by the cat control (28) and that the cat control (28) accelerates and decelerates the movement of the cat (4) in dependence on the load of the cat (4) and the cat maximum available driving force of the travel drive (8) controls. Computer program according to claim 11,
characterized in that the processing of the machine code by the cat controller (28) causes the cat controller (28) to implement the features of any one of claims 2 to 10.

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