EP3532425B1 - Method for the compensation of diagonal pull in cranes - Google Patents

Description

The invention relates to a device for compensating diagonal pull in tower cranes with at least one boom, a boom drive for adjusting an angle and / or a length of the boom and / or for moving a trolley, and a control / regulating device for controlling / regulating the boom drive.

According to the prior art, it is known that when lifting loads by means of a tower crane, a deformation of the geometry or the steel structure of the crane occurs due to the load on the tower, the boom and / or the boom bracing. This deformation leads to a diagonal pull of the rope or the load rope of the tower crane.

The WO 2016/128119 A discloses a tower crane with a boom, a boom drive for adjusting an angle of the boom, a sensor for detecting the angle and a control /

Control device for controlling the boom drive. If the load is now lifted from the ground or at the moment when the load hardly touches the ground or no longer touches the ground at all, a pendulum movement of the now freely suspended or raised load occurs due to the inclined pull of the rope. Likewise, when weaning a load, a relaxation of the steel structure or the tower crane lead to the fact that the tower crane springs back and thus again causes a diagonal pull of the rope. This goes hand in hand with possible dangers, such as the occurrence of a swaying load, which can lead to property damage or personal injury, such as crushing, especially in confined spaces. Furthermore, the horizontal movement of the load can lead to the tower crane's permissible load torque being exceeded.

As is well known, experienced crane operators compensate for the diagonal pull by correcting the outreach, e.g. by moving a trolley on trolley jib cranes or by adjusting the jib angle on luffing jib cranes. In luffing jib cranes, where an inclination sensor is usually installed in the jib, the change in angle due to the load can be detected. This gives the crane driver the opportunity to correct the boom angle to the original value before the load is lifted off the ground. However, this is not done automatically, i.e. the crane driver has to control two drives in parallel to lift a load. In addition, only the bending angle of the tower and boom is compensated for, but not the deflection of the tower or a horizontal path or a deviation from the horizontal of the overhead crane as a result of the tower bending. With trolley jib cranes, there is usually no way of detecting the deformation.

Against this background, the object of the invention is to provide a device by means of which the compensation of the diagonal pull in tower cranes can be improved or simplified.

According to the invention, this object is achieved by a device for compensating diagonal pull in tower cranes with the features of claim 1. Advantageous designs are the subject of the subclaims. Accordingly, a device with at least one boom, a boom drive for adjusting an angle and / or a length of the boom and / or for moving a Trolley, a sensor for detecting the angle of the boom and / or the deformation of at least part of the tower crane and a control / regulating device for controlling the boom drive is provided, the sensor value detected by means of the controller when a load is lifted and / or set down by the tower crane - / control device and the boom drive is kept constant.

The boom drive can be, for example, a motor winch for changing the bracing of the tower crane or the position of the trolley and / or a hydraulic cylinder piston device by means of which the boom can be pivoted.

Thus, the device according to the invention can also be applied to or coupled to a mobile tower crane and used accordingly to reduce or prevent diagonal pull in mobile cranes.

The sensed sensor value can mean an angle of the boom that is spanned by the boom and the horizontal. Alternatively, the sensor value can be a value that is proportional to a deformation of the tower crane and, for example, corresponds to a tension in the crane structure. By keeping the sensor value constant, it is meant that the open-loop and closed-loop control device detects a first actual value by means of the sensor and, in the event of a subsequent change in the first measured actual value, controls / regulates the boom drive so that the error or the change or deviation is minimized between an actual value measured initially and a deviating value measured afterwards. The deformation of the tower crane can be, for example, the bending of the tower or the boom of the tower crane. In this way, according to the invention, diagonal pull compensation can advantageously be carried out using sensors provided in known tower cranes.

In a preferred embodiment, it is conceivable that the boom drive is a pull-in winch or a guy winch. The corresponding winch can be controlled or regulated via the control / regulating device for moving the boom so that the sensor value or parameter detected by the sensor is constant or a deviation between a sensor value measured first and a value measured during further operation of the tower crane is reduced or . is minimized. It is conceivable that the pull-in winch or the guy winch is used to change the length of the boom of the tower crane by extending or retracting the boom accordingly. As a result, the diagonal pull can also be reduced, but not fully compensated, since the deflection of the tower or the boom is not compensated. Alternatively, it is also conceivable that the boom drive is designed as a cylinder piston device and is coupled to the boom for pivoting the boom.

In a further preferred embodiment, it is conceivable that the at least one sensor is an inclination sensor, an optical sensor, a length transmitter for measuring deformations, a GPS sensor and / or a cable sensor in or on a bracing of the tower crane. Accordingly, it is possible to use more than one sensor for recording the respective crane parameters or the geometric design or deformation of the tower crane. In particular, it is possible to use more than one sensor in combination for detecting the alignment or deformation of the tower crane.

In a further preferred embodiment, it is conceivable that the control / regulating device controls the boom drive on the basis of a reference value calculated from a plurality of sensor values. The calculated reference value can be, for example, the load moment, which can be derived from the weight of the load lifted by the tower crane and the corresponding outreach or from the supporting forces acting on the tower crane and the outreach.

In a further preferred embodiment, it is conceivable that the ratio of the sensor value and / or reference value to the cantilever displacement due to the deformation of the tower crane is scaled or determined and / or calculated with a test weight. The rigidity and the crane structure or the geometry of the tower crane can be used for the computational determination of the relationship between the sensor value or the reference value and the projection displacement. The invention is also directed to a tower crane having a device according to any one of claims 1 to 7.

• Figur 1a: Gattungsgemäßer Turmkran mit auf dem Untergrund aufliegender Last;
• Figur 1b: Gattungsgemäßer Turmkran kurz vor dem Anheben einer Last;
• Figur 1c: Gattungsgemäßer Turmkran kurz nach dem Anheben einer Last;
• Figur 2a: Turmkran mit erfindungsgemäßer Vorrichtung zur Kompensation vom Schrägzug mit auf dem Untergrund aufliegender Last;
• Figur 2b: Turmkran mit erfindungsgemäßer Vorrichtung zur Kompensation vom Schrägzug kurz vor dem Anheben einer Last;
• Figur 2c: Turmkran mit erfindungsgemäßer Vorrichtung zur Kompensation vom Schrägzug kurz nach dem Anheben einer Last;
• Figur 3: Wirkstruktur bei der Nutzung eines Turmkrans mit erfindungsgemäßer Vorrichtung;
• Figur 4a-4c: Turmkran beim Anheben einer Last;
• Figur 5: Kennlinie des Lastmoments und der Ausladungsverschiebung eines Turmkrans;
• Figur 6: Kennlinie des Lastmoments und der Ausladungsverschiebung eines Turmkrans mit Zeitpunkt des Abhebens einer Last;
• Figur 7: Kennlinien der Ausgabewerte eines Absolutwertgebers und des Auslegerwinkels eines Turmkrans ohne Last und mit maximal zulässiger Last;
• Figur 8: schematische Ansicht einer abweichenden Auslegerneigung gemäß einem ersten Ansatz; und
• Figur 9: schematische Ansicht einer abweichenden Auslegerneigung gemäß einem zweiten Ansatz.

Further details and advantages of the invention are explained with reference to the embodiments shown by way of example in the figures. Show:

• Figure 1a : Generic tower crane with load resting on the ground;
• Figure 1b : Generic tower crane shortly before lifting a load;
• Figure 1c : Generic tower crane shortly after lifting a load;
• Figure 2a : Tower crane with a device according to the invention for compensating diagonal pull with the load lying on the ground;
• Figure 2b : Tower crane with device according to the invention to compensate for diagonal pull shortly before lifting a load;
• Figure 2c : Tower crane with device according to the invention for compensating diagonal pull shortly after lifting a load;
• Figure 3 : Knitted structure when using a tower crane with a device according to the invention;
• Figures 4a-4c : Tower crane lifting a load;
• Figure 5 : Characteristic curve of the load torque and the radius displacement of a tower crane;
• Figure 6 : Characteristic curve of the load moment and the radius displacement of a tower crane with the time of lifting a load;
• Figure 7 : Characteristic curves of the output values of an absolute encoder and the jib angle of a tower crane without load and with maximum permissible load;
• Figure 8 : a schematic view of a different boom inclination according to a first approach; and
• Figure 9 : schematic view of a different boom inclination according to a second approach.

Figure 1a shows a tower crane 1 known from the prior art with a boom 2 which does not have a device according to the invention for compensating diagonal pull. The tower crane 1 comprises a boom drive 3 which can adjust the boom 2 and / or move the trolley 7. When the load 6 is placed on the ground, the tower crane 1 is at least not loaded by the load 6 and therefore also has no deformations caused by the load 6.

The term boom drive 3 can mean a drive for moving the boom 2 or any other drive provided on the tower crane, such as a pull-in winch 8 or guy winch 9, by means of which further or other crane components can be moved.

When the load 6 is lifted from the ground, the tower crane 1 is correspondingly loaded, even while the load initially remains on the ground or touches the ground. This leads, among other things, to a horizontal movement of the

Upper crane or in particular the boom 2 and a corresponding diagonal pull of the rope, such as Figure 1b shows.

Lifts the load 6 as in Figure 1c shown from the ground, it results from the previously in Figure 1b Shown horizontal movement or rotary movement of the overhead crane at the moment of lifting the load 6 an inclined position or an inclined pull of the rope of the tower crane 1, which can lead to load swing and correspondingly to an increase in the radius of the load swing.

The Indian Figure 2a The tower crane 1 shown with the device according to the invention for compensating the diagonal pull initially hardly differs from that in FIG Figure 1a shown, known from the prior art tower crane 1, wherein in Figures 1a and 2a each tower cranes are shown in an unloaded state. However, the tower crane 1 according to the invention begins according to FIG Figure 2b To lift the load 6 while it is still on the ground or still touching the ground, according to the invention the overhang of the tower crane 1 can be automatically reduced, whereby the diagonal pull is correspondingly reduced and a pendulum movement is prevented when the load 6 is raised further. If the tower crane 1 lifts as in Figure 2c If the load is shown from the ground, according to the invention there is no diagonal pull at that moment and no load oscillation occurs. As in Figure 2b the trolley 7 is shown moving and / or the boom 2 is pivoted so that the rope has no diagonal pull or is arranged vertically.

Using the in the Figures 2a to 2c The sensor 5 shown, for example, the inclination of the boom 2, the deformation based on a detected change in length of the boom 2 and / or the tension in the bracing of the tower crane 1 can be detected.

At least one corresponding sensor 5 can be provided, for example, on the boom 2 or, alternatively or in addition, on other components such as the tower of the tower crane. The control / regulating device 4 can detect the values detected by the sensor 5 or by the sensors 5 and on the basis of this, determine how the boom drive 3 is to be controlled so that there is as little diagonal pull as possible.

In order to adjust the control / regulating device 4, which can be designed as part of the tower crane 1, for example, to control the boom drive 3, a known test weight can be lifted by means of the tower crane 1, whereby the detected sensor values can be stored accordingly. This can be carried out with different boom angles or projections of the tower crane 1. A correspondingly created table of values with the recorded sensor values, the test weight and / or the corresponding boom angles or projections can be used to compensate for the diagonal pull when the crane 1 is in operation.

Figure 3 shows a schematic representation of the active structure when using a tower crane 1 with a device according to the invention. In this case, one or more reference variables are initially determined that are clearly related to the deformation of the tower crane 1 or the steel structure of the tower crane 1. Likewise, through the interaction of two or more sensors 5, an in particular computational variable can be generated or recorded. The following sensors can be used in any combination and number: load torque sensors, inclination sensors in the tower and / or boom 2 of the tower crane 1, force sensors or a measuring axis or a tensile force sensor in the hoist rope line, extension sensors, force sensors in the bracing, in the guy rope, in the neck rope and / or in the pull-in rope, GPS sensors, optical sensors such as a camera, force sensors and / or strain sensors and / or length sensors in the steel structure of the crane 1, force sensors and / or hydrostatic pressure sensors in the support of the tower crane 1, pressure sensors in an adjusting cylinder of the Tower crane 1 and / or absolute encoder on a cable drum or winch.

A transfer function can be used from the determined reference value or from the determined reference values generated or determined the deformation of the tower crane 1 become. The transfer function can be mapped, for example, with a computational relationship or a map. The deformation can correspond, for example, to a shift in the projection and / or to a change in the angle of the tower and / or boom 2. Depending on the crane type, different crane configurations or tower / boom configurations or hoisting rope reeving can be taken into account.

• Die Übertragungsfunktion kann fest in einer Steuerung bzw. in der Steuerungs-/Regelungsvorrichtung 4 hinterlegt sein. Vorliegend können die Begriffe der Steuerung und der Steuerungs-/Regelungsvorrichtung 4 synonym verwendet werden.
• Die Übertragungsfunktion oder die Übertragungsfunktionen können vom Kranhersteller einmalig, zum Beispiel durch Messungen und/oder durch Berechnungen ermittelt und dann fest in der Steuerung bzw. Steuerungs-/Regelungsvorrichtung 4 hinterlegt werden.
• Die Übertragungsfunktion kann durch Referenzmessung bzw. durch Skalieren bestimmt sein. Bei einer oder mehreren Messungen können die Bezugsgröße bzw. die Bezugsgrößen und zusätzlich die Verformung gemessen werden, um deren Zusammenhang zu ermitteln.
• Die Übertragungsfunktion kann durch Kombination aus Rechnung und Referenzmessung bestimmt werden. Der Zusammenhang zwischen Bezugsgröße und Ausladungsverschiebung kann in der Kransteuerung hinterlegt sein, kann aber zudem durch eine Referenzmessung überprüft und/oder angepasst werden.
• Die Übertragungsfunktion kann durch deren Berechnung in der Steuerung bzw. Steuerungs-/Regelungsvorrichtung 4 ermittelt werden.
• Die Übertragungsfunktion kann an die Steuerung bzw. Steuerungs-/Regelungsvorrichtung 4 über beispielsweise UMTS, LTE, 4G und/oder 5G gesendet werden. Schließlich kann gemäß dem gezeigten Wirkprinzip die nun bekannte Verformung des Turmkrans und damit der Schrägzug angezeigt und korrigiert bzw. ausgeglichen werden.
• Bei der Anzeige der Verformung wird die Verformung lediglich visualisiert, z.B. auf einem Display. Der Bediener hat damit die Möglichkeit, selber die Korrektur beispielsweise über eine manuelle Steuereinrichtung vorzunehmen.
• Bei einer automatischen Korrektur kompensiert die Kransteuerung die Ausladungsverschiebung vollautomatisch. Dieser Modus könnte entweder dauerhaft aktiv sein oder vom Bediener nach Bedarf z.B. über einen Wahlschalter und/oder eine Displayeingabe aktiviert werden.
• Die Korrekturbewegung kann auch vom Bediener über einen Taster, einen Steuerhebel und/oder über eine Displayeingabe gesteuert werden. Die Fahrbewegung zum Ausgleich des Schrägzugs wird damit bewusst vom Bediener vorgegeben.

There are the following options for determining the transfer function:

• The transfer function can be permanently stored in a controller or in the control / regulating device 4. In the present case, the terms control and the control / regulating device 4 can be used synonymously.
• The transfer function or the transfer functions can be determined once by the crane manufacturer, for example by measurements and / or by calculations, and then permanently stored in the control or control / regulating device 4.
• The transfer function can be determined by reference measurement or by scaling. In the case of one or more measurements, the reference variable or the reference variables and, in addition, the deformation can be measured in order to determine their relationship.
• The transfer function can be determined by a combination of calculation and reference measurement. The relationship between the reference variable and the shift in the radius can be stored in the crane control, but can also be checked and / or adjusted by means of a reference measurement.
• The transfer function can be determined by calculating it in the control or control / regulating device 4.
• The transfer function can be sent to the controller or control / regulating device 4 via, for example, UMTS, LTE, 4G and / or 5G. Finally, according to the operating principle shown, the now known deformation of the tower crane and thus the diagonal pull can be displayed and corrected or compensated for.
• When the deformation is displayed, the deformation is only visualized, for example on a display. The operator thus has the option of making the correction himself, for example using a manual control device.
• With an automatic correction, the crane control automatically compensates for the shift in the radius. This mode could either be permanently active or activated by the operator as required, for example via a selector switch and / or a display input.
• The correction movement can also be controlled by the operator via a button, a control lever and / or via a display input. The operator consciously specifies the travel movement to compensate for the diagonal pull.

The deformation of the tower crane 1 can be measured, for example, using a payload sensor and an outreach sensor.

In a first approach, the corresponding sensors 5 for measuring the payload and the outreach can be installed in the tower crane 1. The load torque, which in this case represents the reference variable, is computationally determined in the crane control from these two sensors 5. It is also conceivable that in addition to Load moment the radius is a second reference value. This essentially depends on the crane structure and the resulting static relationships.

• Δs = s_real - s_{Ausladungssensor}

The diagonal pull can then be determined by a reference measurement or by scaling. After the tower crane 1 has been assembled, a reference measurement can be used to determine the relationship between the reference variable “load torque” and the shift in the radius. The shift in the cantilever can correspond to the deformation of the steel structure of the tower crane 1. For this purpose, a known payload is raised at a known radius and the increase in the radius resulting from the lifting is measured. The displacement shift Δs results from the following equation:

• Δs = s _real - s _{extension sensor}

Figures 4a-4c make this connection clear. Figure 4a shows a tower crane with a load placed on the ground, the crane not being loaded by the load. Figure 4b shows a tower crane in which the load to be lifted by it is still on the ground, but has already applied part of its weight to the tower crane. In this state, a horizontal movement of the tower crane 1 or the overhead crane is effected. Figure 4c shows the tower crane from Figure 4b at the moment the load is lifted from the ground, the measured cantilever magnification Δs in the Figures 4b and 4c is shown.

This example assumes a linear relationship between load torque and cantilever displacement, which is shown in Figure 5 is shown. Non-linear relationships would also be conceivable. The relationship determined above is stored in the crane control 4.

The crane operator can activate the automatic correction of the diagonal pull on a display in order to compensate for an undesired diagonal pull. When a load is lifted, the payload and the outreach become the, especially online Load torque calculated. The outreach with the trolley 7 is automatically corrected by the correspondingly determined outreach shift. $$\mathrm{s}*=\mathrm{s}-{\mathrm{s}}_{\mathrm{cor}}$$

Since the tower crane 1 is initially deformed before the load 6 is lifted and this deformation is compensated for at the same time or with a time delay, there is no longer any diagonal pull at the time when the load 6 is lifted from the ground. This situation is in Figure 6 and in the Figures 2a to 2c shown.

If the invention is used in connection with a mobile tower crane with an adjustable boom, another operating principle is also possible. So it is conceivable that the deformation of the steel structure is measured by inclination sensors in the boom and absolute encoder of the guy winch 9. In this situation, the diagonal pull can be determined by means of a transfer function that can be permanently stored in the controller. The diagonal pull is then compensated for using appropriate correction commands.

In this case, in the case of a mobile tower crane with adjustable boom, the boom inclination is adjusted with the guy winch 9, which is designed with an absolute encoder. There is a relationship between the values of the inclination sensor in the boom and the absolute value encoder of the guy winch 9. When attaching a payload, the inclination of the boom changes due to the deformation of the steel structure of the tower and boom and the stretching of the guy rope, while the absolute encoder of the guy winch remains constant. This changes the relationship between the boom angle and the absolute encoder. More on this is the Figure 7 removable.

The relationship between the measured variables of the inclination sensor and the absolute value encoder of the guy winch are permanently stored in this example in the unloaded state (without payload). In this way, an expected angle of inclination is assigned to each value of the absolute encoder. When lifting a Payload, there is now a discrepancy between the expected and actual boom inclination. In the first approach, this deviation can be corrected by correcting the boom angle with the guy winch 9 to the original value. Here, however, only the bending angle of the tower and boom is compensated, but not the deflection of the tower (horizontal path of the overhead crane as a result of the tower bending). More information is available on this Figure 8 removable.

In a second approach, in addition to compensating for the angle, the deflection of the tower can also be compensated for. In this case, the boom angle must be set steeper than originally when there is a load. More on this is Figure 9 removable.

To compensate for the diagonal pull, the crane operator is shown the diagonal pull visually on a display, possibly with an acoustic signal. With a button or an input on the touch display, he can then trigger the correction movement or a correction command to adjust the boom.

Claims (7)

1. Tower crane (1) comprising a device for compensation of diagonal pull in a tower crane (1) comprising at least one boom (2), at least one boom drive (3) for adjusting an angle and/or a length of the boom (2) and/or for displacing a trolley (7), comprising at least one sensor (5) for recording the angle of the boom (2) and or the deformation of at least a portion of the tower crane (1), and comprising at least one control/regulating device (4) for controlling the boom drive (3), wherein the recorded sensor value is kept constant by means of the control/regulating device (4) and the boom drive (3) during raising and/or lowering of a load (6) by the tower crane (1).
2. Tower crane (1) according to claim 1, characterised in that the boom drive (3) is at least one retracting winch (8) or guying winch (9).
3. Tower crane (1) according to claim 1, characterised in that the boom drive (3) is a hydraulic piston-cylinder apparatus.
4. Tower crane (1) according to any of the preceding claims, characterised in that the sensor (5) is a tilt sensor, an optical sensor, a length sensor for measuring deformations, a GPS sensor, and/or a cable sensor in or on a guy of the tower crane (1).
5. Tower crane (1) according to any of the preceding claims, characterised in that the control/regulating device (4) actuates the boom drive (3) on the basis of a reference value calculated from a plurality of sensor values.
6. Tower crane (1) according to claim 5, characterised in that the reference value is the load torque calculated from the outreach of the tower crane (1) and the weight of the load (6) or the supporting forces.
7. Tower crane (1) at least according to claim 5, characterised in that the ratio of the sensor value and/or reference value to the outreach shift on account of the deformation of the tower crane (1) is scaled or determined and/or calculated mathematically using a test weight.

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