DE102013012019B4 - Crane, in particular mobile crane - Google Patents

Abstract

Crane (1), in particular a mobile crane (2), comprising a movably mounted outrigger (6), a detection unit (44) which is set up to control a number of positions (47) on the boom (6) at a suspension point (30). an evaluation unit (48), which is adapted to determine from a detected by the detection unit (44) position (47) a relative position of the payload (40) to a crane fixed reference point, and which further thereto is set up to determine from a determined relative position a deviation parameter (49) characterizing the deviation from a reference position, the reference position being given by a relative position of the payload (40) to the reference point with stationary arm (6), and a control unit (50), which is set up to control and / or regulate the movement of the arm (6) as a function of the deviation parameter (49) determined by the evaluation unit (48), wherein the detection unit (44) comprises a camera (42) whose viewing angle is oriented in the direction of the payload (40) and which is arranged and aligned in the vicinity of the suspension point (30) on the boom (6) above a roller carrier (32) in that the roller carrier (32) in the middle of a camera image is selected as the reference point for the reference position of the payload (40).

Description

The invention relates to a crane, in particular a mobile crane, which comprises a movably mounted arm on which a payload is suspended at a suspension point. The invention is particularly concerned with the control of the movement of the boom.

A mobile crane usually comprises a multi-axle chassis to ensure mobility and a rotatably mounted on the chassis superstructure on which the boom of the mobile crane is arranged. The boom can usually extend telescopically. Furthermore, a lattice mast tip or a boom extension can be attached to the end of the jib, which increases the reach of the jib above the ground. The payload is hung at the end of the lattice mast tip or the boom extension, or in the absence of this at the end of the boom, attached to a roller carrier mounted there over a rope, between roller carrier and payload still a roller bottle can be arranged. During operation of the mobile crane, the chassis is fixed on the ground, for which purpose hydraulic feet can be used. The arranged on the superstructure boom has when moving a payload usually a predetermined length and is therefore usually not further extended. When operating the boom with a luffing tip, the boom for moving the payload is usually not pivoted against the ground. A change in radius is possible by changing the rocking angle of the rocking tip. When operating with a fixed tip or only with the boom is pivoted to spend the payload of the boom under radius change also against the ground

The stroke of the payload is done via a train on the payload carrying rope. A movement of the payload above the ground can be achieved in the azimuthal direction with respect to the axis of rotation of the superstructure via a rotation of the upper carriage against the fixed chassis. Moreover, as mentioned, a movement of the payload in the radial direction can take place via a change in the luffing angle of the lattice mast tip.

The payload rushes in a rotation of the upper carriage of the movement of the boom or the lattice mast tip mounted roller carrier due to the inertia behind, while on the other hand slows down or stopping a rotational movement of the upper carriage, the payload still in the direction of the movement. Due to the dimensions and the high payloads of up to several hundred tons, the relative movement of the payload in the azimuthal direction can exert significant lateral forces in the lateral direction on the boom and / or the boom extension and / or the lattice mast tip, and therefore the risk of permanent damage due to Bent up to a break can be exposed. In particular, the boom may be exposed during operation in an approximately vertical position with angled luffing a tremendous torsional load, which can lead to failure.

Furthermore, with a payload having a large cross-sectional area at a comparatively small thickness, such as e.g. an insulating plate made of heat-insulating material or a wall element made of lightweight concrete, also by the air resistance, the movement of the payload be braked. This also creates an undesirable transverse load on the boom and / or the boom extension and / or the lattice mast tip with the already mentioned possible consequences for the statics of the entire mobile crane.

A possible lateral load due to the mass inertia or the air resistance of the payload is moreover not only to be considered against the background of imminent damage to the mobile crane itself. In particular, possible canting of the cantilever, lattice mast tip or cantilever extension also affects the environment, e.g. for surrounding buildings, a danger.

From the documents DE 10 245 970 A1 . DE 10 2009 032 267 A1 . DE 10 2006 001 279 A1 . DE 20 2008 018 260 U1 . WO 97/45357 A1 and DE 195 19 368 A1 Each different approaches are known to determine a deflection of the payload in operation and to take into account, for example, in a path planning when spending the payload and / or to reduce oscillations.

The invention has for its object to provide a crane, which minimizes the risk of damage to the boom by the lateral forces occurring during a movement of the boom as possible.

The object is achieved by a crane, in particular a mobile crane, with the features of claim 1. This crane comprises a movably mounted boom, a detection unit which is adapted to detect a number of positions of a boom suspended on a suspension point payload an evaluation unit, which is set up to determine from a position detected by the detection unit a relative position of the payload to a crane-fixed reference point, in particular to the suspension point on the boom, and which is further configured to determine the deviation from a determined relative position The reference position is characterized by a relative position of the payload to the crane fixed reference point, in particular the suspension point, given a non-moving boom, and a control unit, which is adapted to the movement of the boom in dependence of the deviating determined by the evaluation unit deviation parameter control and / or fix.

In the following description of the invention is in the mention of the term "boom" a possibly arranged on the boom lattice mast tip and / or possibly arranged on the boom boom extension is included.

The invention is based, in a first step, on the fact that a possible solution to the problem is provided by a reinforced construction of the cantilever, e.g. by adding more cross bracing or stiffening elements, the disadvantage is that, in addition to increasing material and assembly costs and thereby increasing production costs for the crane, the center of gravity of the boom boom mesh top system also tends to shift upwards. As a result, the connection of the boom to the superstructure and the connection of the superstructure are exposed to the chassis higher loads, which is constructively taken into account. However, this is undesirable for the sake of simplicity.

In a second step, it is recognized that a transverse load, which can occur with a movement of the boom, is an intrinsic consequence of the physical system of boom and payload, and thus - since a reinforced construction for better absorption of the lateral load is not desired - the lateral load can be reduced during operation of the crane by changing a motion parameter. The boom and the like by means of a rope o.ä. suspended payload inevitably form an excited, possibly damped by the air resistance of the payload pendulum with a movement of the boom. Accordingly, to effectively control possible lateral forces, the free parameter of this system must be controlled, in this case, the excitation of the payload by the movement of the boom itself. This means that the movement of the boom is to be controlled or regulated depending on the response , which the payload in turn to the suggestion by a rope or the like. transmitted movement of the boom reproduces.

The physical design of the detection makes use of optical techniques. In particular, the detection of a first position for determining the reference position can also be carried out several times in succession to ensure that the payload after a preceding movement of the boom or after a lifting operation by a Zugseilbewegung is essentially in a rest position and any previously excited vibrations already sufficiently decayed are to be able to speak of a rest position within the scope of the resolution of the detection unit.

From the detected first position of the payload is the evaluation unit, taking into account the suspension by a rope o.ä. a relative position of the payload with respect to a crane-fixed reference point, in particular with respect to their suspension point, determined on the boom. This relative position forms as reference position together with a crane-fixed reference point, as which in particular the suspension point of the payload can be selected, the coordinate system, in which a lateral deflection or a pendulum movement of the payload, in particular a movement in which a transverse force is exerted on the boom , is to be interpreted as a displacement or movement relative to the first detected position with respect to the suspension point. Specifically, however, the reference position and thus the coordinate system is determined intrinsically by the detection unit detects a crane fixed reference point, concretely the roller carrier, together with the payload, so that the relative position of the payload directly from the data of the detection without the need for further evaluation.

When the boom moves, a second position of the payload is detected. The time interval between the start of the movement of the boom and the detection of the second position is preferably to be chosen so that on the basis of the known operating parameters such as the mass of the payload, the radius of rotation of the movement of the suspension point, the angular acceleration of the boom movement and based on the design parameters of Jib a critical load of the boom by shear forces in this phase of motion is sufficiently high probability to exclude.

From the detected second position, a further relative position of the payload with respect to the crane-fixed reference point is determined by the evaluation unit, and the relative position thus determined is compared with the reference position. In this way, it is possible to determine how far the payload has been deflected out of the rest position by the movement made with respect to the reference point up to the time of the detection of the second position. This deviation is quantified in a deviation parameter, preferably a deflection angle of the pendulum or a Cartesian distance to the reference position. The control unit is now set up to To control or regulate the movement of the boom as a function of the deviation parameter. Such a movement is, for example, an up or luffing or turning of the boom. Control of the movement of the boom may be accomplished, for example, by adjusting a velocity and / or an acceleration of the boom based on a predetermined table for different values of the deviation parameter. A control considers the deviation parameter in particular by a setpoint / actual value comparison and accordingly changes the manipulated variable used, for example the speed or the acceleration of the movement of the boom.

After a sufficiently short time interval, it is preferable to detect a further position of the payload, from which a further relative position and a corresponding deviation parameter are to be determined, wherein the time interval should preferably be selected such that a critical load on the basis of the known operating parameters and the design parameters of the boom Jib in this movement phase is sufficiently high probability to exclude.

Accordingly, a determined during the movement of the boom relative position of the payload is used in particular for controlling or regulating an acceleration operation of the boom or superstructure, for example, in a braking operation of the movement of the boom or superstructure, after reaching the standstill of the boom or in the Starting phase at the beginning of the movement of the boom or superstructure to avoid excessive oscillation of the payload due to the inertia. In particular, this can be done via a table of desired values for the deviation parameter as a function of the remaining travel distance of the movement and / or the mass of the payload and / or the speed and / or the acceleration of the movement over already traveled distance sections.

The detection unit comprises a camera whose viewing angle is oriented in the direction of the payload. A camera can have a small space consumption and low acquisition costs even at high resolution, so that a compact and inexpensive construction of the detection unit is made possible. In addition, the evaluation of the positions captured on camera images by means of automatic image recognition is particularly simple. Preferably, the camera can be arranged on the boom itself, so that during a movement of the boom, the viewing angle remains aligned in the direction of the payload, without an adjustment is necessary. In particular, a camera arranged on the boom can resolve a pendulum movement of the payload with a sideways movement or a rotation of the boom very precisely.

The camera is also located near the suspension point on the boom. The viewing angle of the camera is then preferably to choose vertically downward on the hanging below the camera payload. In particular, in this case, the camera may be provided with a small alignment mass to keep the angle of view during rocking movements of the boom in the direction of the payload. By a view of the payload in the direction of gravity, the reference position and a deviation thereof can be detected particularly accurately, specifically the camera is near the suspension point above the roller carrier aligned so that the roller carrier in the center of a camera image as a reference point for the reference position of Payload is selected, and the deviation parameter from the deflection of hanging under the roller carrier hook bottle can be determined.

Conveniently, a target device is further included, which is attached to the payload or to a hanging between the payload and the suspension hook hook bottle. This simplifies the automatic detection of a position of the payload, specifically the optical detection by the camera. In this case, the target device may be applied to the payload or the hook bottle as a mark comprising a target cross. Preferably, the aiming device is to be arranged so that it marks the center of the viewing angle of the camera when the boom is stationary.

The control unit is preferably set up to control or regulate the movement of the boom in such a way that the deviation parameter for the relative position of the payload with respect to the reference position does not exceed a predetermined tolerance range. The tolerance range is to be adapted for each movement of a payload to the respective operating parameters such as the mass of the payload, the rotational radius of the movement of the suspension point, the angular acceleration of the boom movement and / or the design parameters of the boom. Thus, the payload with as high as possible, but the statics in each case ensuring acceleration or speed can be moved, allowing a time-efficient operation with high security.

In this case, the control unit is preferably configured, upon reaching the limit of a predetermined tolerance range for the deviation parameter of the relative position of the payload with respect to the reference position, to control or to control the movement of the boom by reducing and / or maintaining the acceleration and / or by slowing the movement speed regulate. In particular, in this case, the tolerance range may have a limit range, upon reaching the deviation parameter, the movement of the boom is slowed down, the border area may be divided into a number of subregions, so that a successive exceeding of a number of subregions by the deviation parameter in the direction of the limit Tolerance range has a successive slowing down the movement speed result. In this way, the most efficient movement speed can be achieved with guaranteed statics.

Preferably, the crane further comprising an upper carriage and a chassis, wherein the upper carriage is rotatably mounted on the chassis relative to a vertical axis of rotation, wherein the boom is arranged on the upper carriage, and wherein the control unit is adapted to a rotational movement of the upper carriage in dependence on the deviation parameter for the relative position of the payload with respect to the reference position to control or regulate. Due to the arrangement of the boom on the superstructure of the boom is rotated in a pointer-like shape in a rotation of the upper carriage in plan view, so act by a boom suspended on the payload on the boom forces in the azimuthal direction, which may possibly not fully absorb the boom due to design. The control depending on the detected and evaluated movement of the payload against the boom is particularly advantageous here.

It is also advantageous, if further comprises a display unit which is adapted to display an image of the payload taken by the camera. The image may be displayed in the control of the crane so that a crane operator has additional control over the image of the proper operation of the control unit.

In particular, in this case, the display unit is preferably designed as a monitor, which is further configured to display a reference position of the payload in the image by cross-fading. Thus, a crane operator can read a detected position and its deviation from the reference position directly from the monitor.

An embodiment of the invention will be explained in more detail with reference to a drawing. The only figure shows a crane 1 , which as a mobile crane 2 is formed, from a bird's eye view.

The pictured mobile crane 2 includes a chassis 3 and one on the chassis 3 with respect to a vertical, not shown in the drawing axis rotatably mounted superstructure 4 , At the superstructure 4 is a boom 6 arranged, which consists of individual telescopic elements 8th consists. At the upper end facing away from the chassis 10 of the jib 6 is a lattice mast point 12 appropriate. The boom 6 is on the superstructure 4 with a hydraulic support 14 supported, which is also adapted to the boom 6 upright in the operating state. At the hydraulic support 14 facing away from the upper carriage 4 is the boom 6 by means of a cable 16 secured, which from the upper end 10 over one of the boom 6 spread support 18 runs and on the superstructure 4 is attached. The lattice mast point 12 is by means of a cable 20 curious, which about two columns 22 on the superstructure 4 mounted ballast system 24 is attached under tension.

At the suspension point 30 the lattice mast point 12 depends on the role carrier 32 over a rope 34 a hook bottle 36 down, over another rope 38 the payload 40 is suspended. Near the suspension point 30 is above the roller carrier 32 one as a camera 42 trained registration unit 44 arranged, whose angle of view vertically downwards on the payload 40 is directed. For better recording of the payload 40 through the camera 42 is on the payload still designed as a target cross target mark 46 applied.

The camera 42 can now by means of the target marker 46 a position 47 the payload 40 capture and transfer the information to an evaluation unit 48 pass on which of them a deviation parameter 49 with respect to the reference position of the payload 40 with unmoved arm 6 determined. Alternatively, the deviation parameter 49 from the picture in the camera 42 visible deflection of the hook bottle 36 at the payload 40 is suspended, which are determined from the Cartesian distance of the projection of the hook bottle 36 to the roll carrier 32 can be taken as a reference in a camera image. The deflection of the hook bottle 36 then gives knowledge of the lengths of the ropes 34 and 38 Information about the deflection of the payload 40 , so by the evaluation unit 48 a deviation parameter 49 can be determined. A control unit 50 is adapted to the rotational movement of the upper carriage 4 , and thus the azimuthal movement of the cantilever 6 , the lattice mast tip attached to it 12 and thus the payload 40 , depending on the deviation parameter 49 to control or regulate. The rotational movement of the Oberwagens4 is controlled or regulated in particular such that the hook bottle 36 and / or the destination marker 46 a corresponding tolerance range in the camera 42 do not leave the captured image. If a predefined limit range of this tolerance range is exceeded, the rotational acceleration and / or the rotational movement is reduced or slowed down accordingly.

LIST OF REFERENCE NUMBERS

1

crane

2

mobile crane

3

chassis

4

superstructure

6

boom

8th

Telescopic elements of the boom

10

upper end of the jib

12

Lattice mast tip

14

hydraulic support

16

cable

18

support

20

cable

22

support

24

ballast system

30

suspension

32

roller carrier

34

rope

36

hook block

38

rope

40

payload

42

camera

44

acquisition unit

46

target marker

47

Position of the payload

48

evaluation

49

deviation parameters

50

control unit

Claims (8)

Crane (1), in particular a mobile crane (2), comprising a movably mounted outrigger (6), a detection unit (44) which is set up to control a number of positions (47) on the boom (6) at a suspension point (30). an evaluation unit (48), which is adapted to determine from a detected by the detection unit (44) position (47) a relative position of the payload (40) to a crane fixed reference point, and which further thereto is set up to determine from a determined relative position a deviation parameter (49) characterizing the deviation from a reference position, the reference position being given by a relative position of the payload (40) to the reference point with stationary arm (6), and a control unit (50), which is set up to control and / or regulate the movement of the arm (6) as a function of the deviation parameter (49) determined by the evaluation unit (48), wherein the detection unit (44) comprises a camera (42) whose viewing angle is oriented in the direction of the payload (40) and which is arranged and aligned in the vicinity of the suspension point (30) on the boom (6) above a roller carrier (32) in that the roller carrier (32) in the middle of a camera image is selected as the reference point for the reference position of the payload (40). Crane (1) to Claim 1 in that the camera (42) is provided with a small alignment mass to keep the viewing angle in the direction of the payload during rocker movements of the boom. Crane (1) according to one of the preceding claims, further comprising an aiming device (46) which is mounted on the payload (40) or on a hook bottle (36) suspended between the payload (40) and the suspension point (30). Crane (1) according to one of the preceding claims, wherein the control unit (50) is adapted to control the movement of the boom (6) and / or to regulate so that the deviation parameter (49) does not exceed a predetermined tolerance range. Crane (1) to Claim 4 in that the control unit (50) is set up to control and / or regulate the movement of the boom (6) upon reaching the limit of a predetermined tolerance range for the deviation parameter (49) by reducing the movement speed and / or the acceleration. Crane (1) according to one of the preceding claims, further comprising a superstructure (4) and a chassis (3), wherein the superstructure (4) is rotatably mounted on the chassis (3) with respect to a vertical axis of rotation, wherein the boom ( 6) is arranged on the upper carriage (4), and wherein the control unit (50) is adapted to control and / or regulate a rotational movement of the upper carriage (4) in dependence on the deviation parameter (49). Crane (1) according to one of the preceding claims, wherein a display unit is included, which is adapted to display an image of the payload (40) taken by the camera (42). Crane (1) to Claim 7 wherein the display unit is configured as a monitor which continues is set up to display a reference position of the payload (40) in the image by crossfading.

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