This application claims priority to German Patent Application No. 10 2017 120 613.2 filed Sep. 7, 2017, entitled “VERFAHREN ZUM BEWEGEN EINER LAST MIT EINEM KRAN,” the entire contents of which are hereby incorporated by reference in their entirety for all purposes.
The present invention relates to a method of moving a load using a crane and to a corresponding crane for this purpose.
It is often difficult with cranes to guide a load suspended at a crane hook around obstacles such as building edges or similar. Straight-line travel movements of the lifting hook are namely often required here in which a crane operator has to simultaneously control a number of crane actuators at different speeds. This is mostly only possible for experienced and well-trained crane operators, but typically represents a challenging task for them. It can thus be necessary that a luffing movement, a hoisting movement, a rotation of the superstructure of the crane, and a telescopic movement of the crane boom are simultaneously necessary for a straight-line movement of the lifting hook and of the load suspended thereat. A straight-line movement can be carried out at a constant load height by a simultaneous control of the above-named movements.
It is the aim of the present invention also to make such straight-line movements, such as typically occur on the traveling around an obstacle with the lifting hook at a deployment location of the crane, possible for less practiced crane operators so that demanding load movements can also be carried out without time delays and the work routines associated with a crane can be accelerated.
The above-mentioned problems are overcome with the aid of a method that has all the features of claim 1.
In accordance with the method in accordance with the invention for moving a load using a crane, an origin coordinate system is defined in the crane, an obstacle coordinate system is defined that is fixedly linked to a deployment location of the load movement, a relationship of the at least one obstacle coordinate system with the origin coordinate system is established, a travel path of the hook block at which a load is preferably suspended is predefined and the travel path is converted from the obstacle coordinate system into actuator controls of the crane for a corresponding movement of the load.
It is advantageous here that the travel path of the load is predefined with the aid of the spatially fixed obstacle coordinate system, that is, for example, by an input via a touch-sensitive display, whereby the necessity of inputting parallel control pulses of the plurality of crane drives that differ in their speeds is dispensed with. The individual control pulses are obtained with the aid of a conversion from the obstacle coordinate system that produces as its result the actuator controls of the plurality of actuators of the crane for a corresponding movement in the spatially fixed obstacle coordinate system. Complicated load movements are also possible without problem since the inputting of the travel path with the aid of the spatially fixed obstacle coordinate system is also easily understandable for unpracticed crane operators. The desired travel path can thus, for example, be input from a bird's eye view of the crane deployment location.
Provision can preferably be made that the position, and preferably the orientation, of the load to be moved are furthermore detected in the obstacle coordinate system.
In accordance with an advantageous modification of the invention, the actuator controls for moving the load comprise the individual or common actuation of a luffing movement, of a rotational movement of the superstructure of a crane and/or a telescopic movement of a crane boom.
The present invention is not restricted to the above-named exemplary crane movements, but can also furthermore include crane movements and control commands that are not listed, but that are advantageous on the traveling of a load. It is clear to the skilled person that all the degrees of freedom of the crane to be made use of for a movement of the load can be used.
Provision is furthermore preferably made in accordance with the method that, if the travel path is to be implemented by means of a plurality of actuator control sets, the final set of actuator controls is reached on the basis of specifications that preferably comprise a maximum payload, a maximum speed and/or a minimal energy consumption.
It can thus occur that the travel path to be converted can be carried out by different combinations of crane movements. To resolve such an ambiguity, a travel path is then selected that is optimized with respect to a specification and that, for example, has the greatest payload reserves or permits the highest travel speed.
Provision can further be made that in accordance with the method in accordance with the invention the origin coordinate system is furthermore fixedly linked to the crane and the spatial relationship of the origin coordinate system and the obstacle coordinate system is advised to a crane control. Provision can also be made here that the origin coordinate system is at the center of a slewing ring of the crane.
Since the spatial relationship of the origin coordinate system, that is, the position and orientation of the crane, with respect to the obstacle coordinate system is advised to a crane control, the latter is now able to enter the orientation and the location of the crane into the obstacle coordinate system. The obstacle coordinate system thus also comprises the crane itself in addition to the special topographical and construction features of the crane environment and of the load and can thus carry out payload calculations and the like in a simple manner since the position and orientation of all the relevant objects are known in the obstacle coordinate system.
Provision can further be made that a hook block coordinate system is furthermore defined that is fixedly linked to the hook block of the crane, with a displacement and a rotation of the hook block coordinate system preferably being able to be calculated back to the origin coordinate system fixedly linked to the crane, preferably by the crane control. Since the hook block coordinate system can always be brought into a spatial relationship with the origin coordinate system of the crane due to the positionings of the actuators by the crane control, it is possible to travel to specific characteristic points of the obstacle coordinate system with the hook block or with the hook block coordinate system linked thereto and thus to advise one or more characteristic points of the obstacle coordinate system to the crane control in an uncomplicated manner. It is thereby possible also to correctly include the obstacle coordinate system in the crane control with mobile cranes. This is done, for example, by the perpendicular arrangement of the hook block above a characteristic point of the origin of the obstacle coordinate system (such as a building edge or the like). The crane control receives the required information to correctly position or to enter the obstacle coordinate system into the origin coordinate system fixedly linked to the crane with the knowledge of the controls of the crane required for this hook block position. The calibration of the obstacle with the hook block takes place in the initially present origin coordinate system of the crane. An obstacle coordinate system results on the calibration of the obstacle that thus has a relationship with the origin coordinate system and can be entered into it.
Provision can furthermore be made that a camera is used to define or make known the obstacle coordinate system in the crane control (or in the origin coordinate system), with the hook block coordinate system preferably being aligned superposed with the obstacle coordinate system not yet known to the crane for making the obstacle coordinate system known in a crane control of the crane. If the hook block coordinate system is at the correct position due to an operator input and if it is also correctly aligned, the adopted position and alignment of the hook block coordinate system can be fixed as the origin of the obstacle coordinate system and can be entered into the origin coordinate system by a further operator input. A fast overview can also be quickly obtained in a simple manner with the aid of the camera as to whether the obstacle coordinate system origin set at a characteristic feature of the obstacle coordinate system is congruent with the origin of the hook block coordinate system. Since the orientation of the obstacle coordinate system is also fixed with the aid of the characteristic features of the deployment location (for example with the aid of a building edge or building corner), the obstacle coordinate system can thus be unambiguously advised to the crane control.
In an advantageous embodiment of the method, the known hook block coordinate system is duplicated in a camera image shown on a screen. This duplicate is suitably rotated and moved with the aid of user inputs, preferably via button operation. If it is at the correct position, it becomes the obstacle coordinate system. This is preferably done in that the current location (preferably orientation and position) of the hook block coordinate system is fixed via user input as the origin of the obstacle coordinate system that is then fixedly arranged in the origin coordinate system.
In accordance with the method in accordance with the invention, it is accordingly further possible to use characteristic features of the deployment location, preferably a building edge or another special topographical or construction feature at the deployment location, for the alignment of the hook block coordinate system at the obstacle coordinate system. The obstacle to be traveled around by the load is preferably used for this purpose. It is accordingly possible for the crane control to enter the crane with its origin coordinate system into the obstacle coordinate system and thus to carry out desired travel movements of a load that are input in the obstacle coordinate system with the help of a conversion. The obstacle coordinate system preferably corresponds to a site plan and/or to a construction site plan.
Provision can further be made that the origin of the hook block coordinate system is used to detect the obstacle coordinate system in the crane control in order thereby to make the origin of the obstacle coordinate system and a point of an axis on the obstacle coordinate system known to the crane control (for example, in a 2D system or in a 3D system, a respective point on 2 axes). The orientation and the location of the obstacle coordinate system are thereby supplied to the crane control in an unambiguous manner.
Provision can further be made that radio GPS transmitters are used to detect the obstacle coordinate system in the crane control that permit a conclusion to be drawn on the orientation and location of the obstacle coordinate system in cooperation with a radio GPS receiver of a crane control of the crane present at the crane.
In accordance with a further optional modification of the method, the crane is arranged in the obstacle coordinate system before the specification of the travel path of the load by an operator of the crane and furthermore a payload calculation of the crane is carried out for the desired travel path before the specification of the travel path of the load. Since the exact position of the crane in the obstacle coordinate system can be made known to the crane control in the course of the process, it is then also possible to carry out a payload calculation applicable to the present situation that is not based on planned or estimated probable locations of the crane. Nor is it necessary to exactly travel to the crane location on the construction site used beforehand for a payload calculation.
It is furthermore possible in accordance with a modification of the present method that a tandem hoist of two cranes is provided for the movement of the load. The origin coordinate systems of both cranes are here used in a common obstacle coordinate system, preferably by one of the above-named variants.
Provision can be made here that both cranes are coupled to one another before a traveling of the load via a data link that is used to transmit the coordinates of the hook block of the one crane (preferably in the obstacle coordinate system) to the other crane. The other crane can then coordinate its movements thereto.
Provision is preferably made that the other crane moves the position of its hook block in dependence on the coordinates in the obstacle coordinate system of the hook block of the first crane and in dependence on the desired orientation of the load.
The present invention further comprises an apparatus, in particular an apparatus for carrying out a method in accordance with one of the variants listed above, said apparatus comprising: a crane for moving a load, a crane control for controlling actuators, a coordinate system detection means for detecting and fixing the position and orientation of the crane in a spatially fixed obstacle coordinate system that is fixedly linked to a deployment location of the crane, with the crane control being configured to travel a load on the basis of the detected position and orientation of the crane in the obstacle coordinate system.
The crane control is preferably configured to carry out a payload calculation for a load detected in the obstacle coordinate system or for a load movement after the detection and fixing the position and the orientation of the crane in the spatially fixed obstacle coordinate system.
The coordinate system detection means can here be a hook block whose exact position and orientation with respect to the origin coordinate system of the crane is known to the crane control. The origin coordinate system is here fixedly associated with the crane and is typically at the center of the slewing ring, with the longitudinal extent of the crane being in parallel with the Y axis and with the width direction of the crane being in parallel with the X axis.
It is clear to the skilled person that a plurality of obstacle coordinate systems can also be stored in the origin coordinate system.
The “obstacle coordinate system” can furthermore also be a useful obstacle coordinate system such as a low loader on which the load is to be placed. The obstacle coordinate system can here be at any desired point of the construction site or in the origin coordinate system and can in so doing mark any kind of obstacle.
Further advantages, features, and details of the present invention will become clear with reference to the following description of the Figures. There are shown:
The origin coordinate system of the crane is furthermore also shown in
The conversion carried out in the crane control, that carries out a straight-line movement in the obstacle coordinate system in corresponding controls of the axes and actuators of the crane, typically makes use of the means of coordinate transformation and also of coordinate system transformation.
There is furthermore also the crane-side origin coordinate system whose origin is as a rule at the slewing ring center. The hook block coordinate system 130 that is movable in accordance with the orientation and alignment of the hook block can be recognized as the third coordinate system shown in
The integration of the obstacle coordinate system is more problematic for the crane control here since the origin of this coordinate system changes its orientation and its location depending on the positioning of the crane at the deployment site. A positioning of the crane at the construction site planned in advance will always differ from the later actual implementation. An attempt could admittedly be made to position the crane at a previously measured point; however, this frequently fails due to the restricted maneuverability of the crane and due to other spatial constraints on a construction site. In addition, such an exact specification of the crane position is extremely laborious and would take up a lot of time.
It is therefore necessary to make the obstacle coordinate system 120 known to the crane control at the actual crane deployment location after the positioning of the crane so that the origin coordinate system can be brought into a spatial relationship with the obstacle coordinate system 120. The obstacle coordinate system 120 here must be redefined in the crane control (or the orientation and position of the obstacle coordinate system must be made known to the crane control) when the position of the crane (or of the origin coordinate system) changes.
The use of the obstacle coordinate system 120 is in particular of advantage when a travel movement is desired that is to take place along a straight line.
If all the coordinate systems are known in the crane control, such as shown with reference to
Alternatively to this, it is also possible to indicate absolute points in the obstacle coordinate system that should be worked through by a travel movement of the hook block. It would thus be possible, for example, to define two spatial points that are arranged at the tips of the two movement arrows starting from the hook block to reach the desired travel destination.
The integration of the crane or of the origin coordinate system in the obstacle coordinate system here takes place via the reverse calculation of that position of the hook block at which the hook block coordinate system has been brought into superposition with the obstacle coordinate system with respect to position and orientation.
A third possibility for making the obstacle coordinate system known is shown in
A compass in a portable radio remote control for the crane can likewise be used to make the orientation of the obstacle coordinate system and the origin coordinate system known to the crane control. This is shown by way of example with reference to
It is thus achieved that travel can take place relatively in X or Y of the stored position by means of the master switch. It can, however, not be traveled absolutely here since no information on the movement of the two coordinate systems is known. The obstacle coordinate system is accordingly also not present with location and orientation in the crane control.
The case is also covered by the invention according to which a plurality of the above-shown possibilities for defining or making known the obstacle coordinate system are used.
For this purpose, the obstacle coordinate system should be aligned at a point of the crane deployment location that is as obvious as possible so that in a later procedure, when the crane is actually on the construction site, the origin of the obstacle coordinate system can be relatively easily brought into superposition with the aid of the hook block. In the present case, there is a rectangle obstacle in which an edge should serve as the origin of the obstacle coordinate system. The longer of the two rectangle edges is here equal to the Y axis, the shorter of them is equal to the Y axis. The calibration later is accordingly facilitated by the use of the striking position on the construction site. A building corner or a building edge is particularly suitable here.
The position of the load with respect to the obstacle can then furthermore be defined in the operation schedule program.
Following this step, the travel path of the crane and further intermediate points (attaching the load, rotating the load, etc.) are then defined, with this being able to take place with the aid of a touchscreen or of another input means. It is now possible to carry out a payload calculation in the operation schedule on the basis of the information thus provided. This naturally depends on the type of crane used.
Unlike
Once the payload calculation has been concluded with a positive result, the crane operator automatically travels the hook block to the starting point of the movement of the load. In so doing, he only regulates the speed with the aid of the master switch and checks that no unexpected collisions with obstacles occur. Once the hook block has arrived above the load to be moved, the load is attached. The crane operator then selects the travel path and specifies the speed by means of his control. The selected paths are then semi-automatically or fully automatically traveled through at the predefined speed (cf.
First, the construction site environment is again shown in an operation schedule program, cf.
It must be taken into account here that the travel paths are dependent on one another since the other crane has to adopt a specific position at each point of the one crane. It is of advantage for the calculation and for the entering of the travel path for the two travel paths of the cranes to relate to the obstacle coordinate system.
Both cranes are now each separately calibrated for the obstacle coordinate system, with reference again being made to the methods provided further above for this purpose. A repeat payload calculation can then take place for the planned travel path of the respective crane. If the payload calculation does not produce any difficulties, both cranes move over the load into a position that enables a connection of the load to the respective cranes. Subsequently, the two cranes have to be coupled to one another so that they have a reliable data link to one another. One of the crane operators then takes over the speed control, with provision preferably being able to be made that the other crane operator has to release the load movement. This can be done, for example, with the aid of a button, the so-called dead man's switch. If the so-called dead man's switch is released by the second crane operator, both cranes stop.
Since the crane has different crane drives, that drive of a crane component that can carry out the movement the slowest determines the maximum speed to carry out the movement sequence.
The traveling of the load then takes place such that the first operator increases the speed and his crane starts to move. The crane in so doing transmits the X-Y coordinates of its position of the hook block in the obstacle coordinate system to the other crane. The other crane thereupon changes the position of its hook block using a corresponding regulation so that the desired orientation of the load and the desired movement of the load are achieved. The load is thus traveled as previously defined in master-slave operation. Both cranes stop automatically on too great a difference.
It is possible to carry out a particularly demanding tandem hoist reliably and precisely using the present invention.
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10 2017 120 613.2 | Sep 2017 | DE | national |
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