Method for collision monitoring of a cable-guided load

Abstract

The invention relates to a method for collision monitoring of a load attached to a cable of a working machine, in particular a crane, wherein the working machine comprises a rotating platform rotatable about a vertical axis of rotation, a boom connected to the rotating platform over which the cable is guided, and at least one sensor for detecting the current position and / or movement of at least one movable component of the working machine. According to the invention, based on the sensor data, a predictable braking trajectory of a defined point on the working machine is determined, and based on the determined braking trajectory of the defined point and a computational model, a predictable braking trajectory of the load is calculated.The invention further relates to a working machine, in particular a crane, comprising a rotating platform rotatable about a vertical axis of rotation, a boom connected to the rotating platform over which a cable is guided, and a control unit which receives data from at least one sensor of the working machine relating to a current position and / or movement of a load suspended from the cable, wherein the control unit is configured to carry out the method according to the invention. The invention further relates to a corresponding computer program product.

Description

[0001] The present invention relates to a method for collision monitoring of a load according to the preamble of claim 1, a working machine according to the preamble of claim 11 and a computer program product according to claim 15.

[0002] Methods for collision monitoring of working machines are known from the prior art. These methods typically monitor for collisions between components of the working machine, such as a cable-guided boom, and objects in the machine's vicinity. For this purpose, several sensors and / or cameras can be arranged on the working machine.

[0003] Highly dynamic handling and movement processes occur in work machines with cable-guided loads or tools (hereinafter collectively referred to as loads). If the work machine has to be braked abruptly during a movement, the load will oscillate during braking and even after the movement has stopped. Due to the typically long braking distances of such work machines and the often considerable cable lengths, the loads can move significantly around their nominal position due to these pendulum movements, posing a considerable risk of collision. This dynamic behavior presents a challenge for the operator of the work machine, who must simultaneously perceive changes in the machine's working environment. The associated increased strain can lead to errors. If a collision occurs, this can result in a standstill of the work process, incurring costs.Furthermore, damage to the machinery and endangerment of human personnel may occur.

[0004] The present invention is therefore based on the objective of reducing the risk of collisions when working with rope-guided loads.

[0005] According to the invention, this problem is solved by a method with the features of claim 1, by a machine with the features of claim 11, and by a computer program product with the features of claim 15. Advantageous embodiments of the invention are described in the dependent claims and the following description.

[0006] Accordingly, a method for collision monitoring of a load attached to a cable of a working machine is proposed. In general, all working machines capable of moving loads via a cable are suitable for this method. This could include, for example, a stationary or mobile crane, such as a port crane for handling containers or other goods.

[0007] The working machine comprises a rotating platform that can be turned around a vertical axis and a boom connected to the rotating platform, over which the cable is guided. The term "rotating platform" is to be interpreted broadly and can refer to any rotating structure of a working machine, for example, the superstructure of a mobile crane, a harbor crane, or a cable excavator, or a rotating superstructure of a stationary tower crane. The boom can be rigidly connected to the rotating platform and, for example, permanently horizontally oriented, or it can be movably connected to the rotating platform, in particular by being luffing. It could, for example, be a lattice boom or a telescopic boom.

[0008] The machine includes at least one sensor for detecting the current position and / or movement (this can be a current velocity and / or acceleration) of at least one component of the machine. The sensor data is preferably received by a control unit of the machine, which performs the collision monitoring procedure.

[0009] In this context, a moving component can be understood to be any movable part of the machine, such as the rotary platform, the boom, a luffing jib, but also a gearbox or drive. For example, the current position / movement of a rotary drive on the rotary platform can be determined from its current position and / or movement. The same applies to a luffing cylinder of the boom or any other drive, as well as to gearboxes. In the case of a mobile machine, the moving component can also be a movable undercarriage.

[0010] According to the invention, a predicted braking trajectory of a defined point on the machine is determined based on the data from at least one sensor. The braking trajectory is the path of movement of the defined point that it describes when decelerating from a current movement to a standstill. The defined point can be any point on the machine, preferably a defined point on the boom. The predicted braking trajectory is then the predicted braking trajectory that would result if the current movement of the machine were braked in a controlled manner (e.g., stopping all involved drives and / or applying all available brakes relevant to the respective movement, in particular with maximum braking force), preferably with a specific reaction time between a stop signal and the activation of the braking trajectory.a decision to stop the movement, and the beginning of the braking process is assumed.

[0011] The predicted braking trajectory of the defined point would, however, only allow for collision monitoring of the machine components, such as the boom. The dynamic behavior of the load would not be taken into account. Especially during abrupt braking, a significant pendulum motion of the load typically occurs. For this reason, according to the invention, in a further step, a predicted braking trajectory of the load is calculated based on the previously determined predicted braking trajectory of the defined point and additionally using a computational model that models the dynamic behavior of the load or the cable.

[0012] The method according to the invention makes it possible to determine, for a given movement of the machine, how the load would behave should a braking process occur. This enables significantly more reliable collision monitoring and avoidance than if only the rigid components of the machine were considered.

[0013] The method according to the invention can preferably be used in an assistance system to warn the operator of the machine at an early stage of possible collisions and thus reduce the risk of collisions. Alternatively or additionally, the method according to the invention can be part of a fully autonomous control system for the machine, in which all movements and also the braking process are carried out by a control unit.

[0014] The method according to the invention can be combined with conventional collision monitoring methods. For example, one or more cameras could be installed at at least one suitable position on the machine to capture the machine's surroundings and to detect a collision with obstacles in the environment at an early stage, and, if necessary, to take appropriate countermeasures (e.g., issuing a warning and / or changing or stopping a current movement).

[0015] The predicted braking trajectory of the defined point depends on the current position of the machine and can also depend on the current speed and / or acceleration of one or more moving components of the machine. For example, if the rotary platform is rotated at a higher angular velocity, the braking distance increases, or the predicted braking trajectory of the defined point lengthens.

[0016] In one possible embodiment, the defined point is a point on the boom, in particular a rope exit point at a boom head. The rope exit point can be a point on the boom from which the rope hangs, i.e., where the rope leaves a guide or pulley of the boom and runs to the load. The trajectory of the rope exit point therefore determines the behavior of the load. The expected braking trajectory of the rope exit point can result from the movements of several components or moving parts of the machine, for example, a rotational movement of the turntable and / or a swiveling movement of the boom, as well as, if applicable, a travel movement of the entire machine.

[0017] In another possible embodiment, the predicted braking trajectory of the defined point is determined based on at least one predicted braking trajectory of a moving component of the machine. This could be, for example, the predicted braking trajectory of the rotary platform (rotational movement) or the boom (swivel movement), or corresponding gearboxes / drives.

[0018] Since the movement of the defined point can be composed of several individual movements (e.g. simultaneous rotation of the turntable and swiveling of the boom), the expected braking trajectory of the defined point can optionally also be determined based on a combination of at least two expected braking trajectories of different moving components of the machine.

[0019] It may be provided that each movable component involved in the movement of the defined point is modeled via its own trade model.

[0020] Preferably, data stored in a storage unit or control unit is used to determine the expected braking trajectory of a moving component. This data may relate to the geometry, mass, or other properties of the moving component and / or a braking device that decelerates the component.

[0021] Preferably, to determine the expected braking trajectory of a moving component, consideration is given to how a control system reduces the target speed of the moving component (or of the at least one actuator driving the moving component). This is done in particular using a defined braking function, which is taken into account when determining the expected braking trajectory of the moving component. Preferably, such a braking function exists for each moving component involved in the movement of the defined point.

[0022] Preferably, to determine the expected braking trajectory of a moving component, the actual position and / or speed and / or acceleration of the moving component or the actuator driving it, as detected by sensors, is taken into account. For example, the actual position and speed could be used together.

[0023] In another possible embodiment, the expected braking trajectory of the defined point is determined using a kinematic model of the machine, in particular a kinematic model of at least two movable components of the machine. The kinematic model takes into account, in particular, all components involved in the movement of the defined point and their braking trajectories.

[0024] The kinematic model determines the predicted braking trajectory of the defined point, based in particular on the definition of how a control system decelerates the moving components involved, and on the actual positions and speeds of these components. The component models of the moving parts can be constructed from control elements (in the simplest case, first-order lag elements). The parameterization of the component models of the moving parts can be based on test or identification runs, during which the braking behavior of the respective moving part is recorded or analyzed.

[0025] The procedure can therefore include, as a preliminary step, the execution of at least one test run of at least one moving component, during which the associated trade model is parameterized by capturing and recording actual positions and / or actual speeds and / or actual accelerations of the component.

[0026] In another possible embodiment, the expected braking trajectory of the load is determined based on the previously determined expected braking trajectory of the defined point and on a physical model. The physical model specifically considers and models the behavior of the rope during movement of the machine or when traversing the expected braking trajectory of the defined point; that is, the physical model takes into account the previously determined expected braking trajectory of the defined point. Alternatively or additionally, the physical model can consider the weight of the load and / or a geometry of the load (in particular, at least one dimension of the load) and / or a rope length (in particular, the length between the rope exit point and the load's center of gravity) and / or a wind speed, since these factors can influence the load's behavior during braking.The physical model is used to determine how the load behaves when the previously calculated predicted braking trajectory is traversed during braking. This takes into account that a suspended load will oscillate or swing during braking acceleration.

[0027] In the simplest case, a mathematical pendulum model can be used as a physical model. Here, the load is preferably modeled as a point, the rope has no weight of its own, and the influence of wind is neglected.

[0028] The physical model can receive as input parameters the rope length and / or rope speed and / or the current position and / or speed of the load (e.g. relative to the nominal / vertical position) as well as the determined expected braking trajectory of the rope exit point.

[0029] In another possible embodiment, at least one dimension of the load is mathematically combined with the determined expected braking trajectory of the load to determine an expected collision zone within which the load is expected to move during the braking process. The dimension of the load can be a length or height (for example, the height of a lower edge of the load above the ground or an edge length of the load), an area (in particular, an area seen from above, i.e., the base area), and / or the volume of the load. If, for example, the base area or volume of the load is known, an area traversed by the load can be determined by "traversing" the expected braking trajectory, taking into account the anticipated pendulum movements.The collision area determined in this way should therefore be free of obstacles to prevent a collision during braking. Depending on the dimensions of the load used, the collision area can be two- or three-dimensional.

[0030] In another possible embodiment, the determined probable collision area is compared with environmental data of the machine to detect potential collisions with objects or obstacles. This environmental data pertains to objects located in the vicinity of the machine, and this area may be limited to or extend beyond the machine's working area. The environmental data can consist of an environmental map or mapping material, taking into account, in particular, the height of the various objects. The environmental data can be stored in a memory unit or transmitted to a control unit of the machine (for example, wirelessly). Alternatively or additionally, it is conceivable that the environmental data could be generated or adapted based on sensor measurements or camera recordings from the machine.

[0031] The comparison of the determined expected collision area with the environmental data preferably includes a check to see if the collision area overlaps with an object in the environment, preferably considering only objects whose height is above a lower edge of the load or a lower edge of the determined expected collision area.

[0032] If a collision is detected, a warning can be issued and / or the machine's control system can be automatically activated, particularly to modify or stop its current movement. The warning can be audible and / or visual, for example, displayed on a screen on the machine. This provides the operator with early warning, allowing for timely intervention.

[0033] In another possible embodiment, the predicted braking trajectory of the load is calculated assuming a reaction time between a stop signal and the initiation of braking by the machine. For predicting the braking process, it is assumed that the operator, upon receiving an indication of a potential collision or hazardous situation, does not react instantly by initiating braking, but only after a certain reaction time, which can range from milliseconds to seconds. The longer the assumed reaction time, the longer the predicted braking trajectory and thus the collision area, since the braking process is initiated later.

[0034] Preferably, at least two different predicted braking trajectories of the load are determined based on different assumed reaction times in order to simulate various scenarios. This allows for consideration of cases where the operator only reacts and initiates the braking process after a longer reaction time, for example, due to fatigue or distraction. This increases safety and provides better protection against potential collisions.

[0035] In this process, a separate predicted collision zone is determined for each of the different anticipated braking trajectories and compared with environmental data. This allows for the determination of different predicted collision zones for different assumed reaction times. Some of the predicted collision zones determined in this way can serve as early warning zones, providing the operator with an early warning and / or enabling early intervention in the machine's movement. If a potential collision is detected in an early warning zone, instead of initiating a complete stop, the current movement can be modified, for example, by braking and / or executing an evasive maneuver.

[0036] The different expected collision areas / early warning zones can be displayed to the operator on a display unit in a driver's cab or a mobile control station, for example in different colors.

[0037] In another possible embodiment, the calculation of the expected braking trajectory or the aforementioned expected collision area is performed at regular intervals during the operation of the machine. The prediction can thus be carried out continuously during operation, with a corresponding expected braking trajectory or collision area (possibly with corresponding early warning zones) being determined for each movement. This ensures effective collision monitoring at all times during operation.

[0038] The invention further relates to a working machine comprising a rotating platform rotatable about a vertical axis of rotation, a boom connected to the rotating platform over which a cable is guided, and a control unit that receives data from at least one sensor of the working machine regarding the current position and / or movement of a load suspended from the cable. The working machine can, in particular, be a stationary or mobile crane, for example, a port crane for handling containers or other goods.

[0039] According to the invention, the machine comprises a control unit configured to execute the method according to the invention (i.e., the steps described above that relate to or can be executed by the control unit). The same properties and advantages result for the method according to the invention, which is why a repetitive description is omitted. In particular, all embodiments and features described above for the method according to the invention also apply to the machine according to the invention, in any combination.

[0040] In one possible embodiment, the machine includes an input unit connected to the control unit, via which at least one dimension of the attached load and / or a load type (e.g., a container of a specific size) can be manually entered. The input unit can be located in the operator's cab of the machine. Alternatively or additionally, input via a mobile device is conceivable. Alternatively, the at least one dimension can be transmitted to the machine, particularly wirelessly. It is also conceivable that several load types and / or dimensions (e.g., container sizes) are stored in a memory unit, and the operator can select the corresponding dimensions and / or type.

[0041] Alternatively or additionally, it is conceivable that the dimensions of the load are determined by one or more sensors (e.g. camera and / or lidar).

[0042] In another possible embodiment, the machine includes an output unit, in particular a monitor, which can be located, for example, in the operator's cab of the machine and / or be designed as a mobile device. The control unit is configured to display, in particular graphically, a determined predicted braking trajectory of the defined point and / or a calculated predicted braking trajectory of the load and / or a predicted collision area occupied by the load when traversing the braking trajectory on the output unit. Different colors can be used for different collision areas / early warning zones.

[0043] In another possible embodiment, the working machine includes a storage unit on which environmental data relating to objects located in the environment of the working machine is stored, wherein the control unit has access to or includes access to the storage unit.

[0044] The invention further relates to a corresponding computer program product for carrying out the method according to the invention, which includes instructions that, during the execution of the program, cause the steps of the method described above (in any embodiment) relating to the control unit to be carried out by the control unit of the machine according to the invention. Preferably, the computer program product can be operated on conventional machine controls, so that no retrofitting of hardware components is necessary.

[0045] Further features, details and advantages of the invention will become apparent from the exemplary embodiments explained below with reference to the figures. The figures show: Figure 1: a schematic top view of an embodiment of the machine according to the invention; and Figure 2: a schematic representation of the method according to the invention for collision monitoring of a load.

[0046] The Figure 1Figure 1 shows a schematic top view of an embodiment of the machine 10 according to the invention, which comprises a rotary platform 12 rotatable about a vertical axis of rotation and a boom 14 arranged thereon. A rope for lifting loads (not shown) is guided over the end of the boom, with the rope exit point designated by the number 16. The boom 14 can be pivotally mounted on the rotary platform 12. The machine 10 has a maximum working range 11, which in this embodiment is circular due to the rotatability of the rotary platform 12 through 360°.

[0047] Several objects 40, 42 are located at least partially within the working area 11 of the machine 10 and can therefore, in principle, pose hazards with regard to a possible collision with a lifted load 18. These objects 40, 42, or obstacles, can be other machines, trees, buildings, or the like.

[0048] The load 18 lifted in this embodiment has a rectangular base (in principle, the shape of the load is irrelevant and is taken into account accordingly in the collision procedure described below). The load 18 could, for example, be a container or a grabber, and the working machine 10 could, for example, be a harbor crane.

[0049] Due to the inertia of the working machine 10 and the fact that the load 18 is suspended by a rope, a considerable braking distance results when the current machine movement is slowed down. The load 18 swings and therefore moves over an extended area before coming to a standstill after some time. This swinging behavior and the extended braking distance are taken into account in the method according to the invention, so that more reliable collision warnings and ultimately more effective collision avoidance can be achieved.

[0050] The procedure can be carried out by a control unit of the working machine 10, which may be, for example, the machine control.

[0051] In a first step, the control unit determines a probable braking trajectory 20 of a defined point of the working machine 10, which in the illustrated embodiment is the rope exit point 16 at the boom tip.

[0052] The predicted braking trajectory 20 is a forecasted trajectory or path of movement of the rope exit point 16, which results in particular from the assumption that the operator of the machine 10 brakes the current movement of the machine 10 until it comes to a standstill. The rope exit point 16 moves along the predicted braking trajectory 20 until it comes to a standstill at a stopping point 19. To determine the predicted braking trajectory 20 of the rope exit point 16, it can be assumed that a certain reaction time tR elapses between a signal to the operator that leads to the decision to initiate braking and the actual initiation of the braking process. Furthermore, it can be assumed that the braking is carried out using at least one braking device and with maximum braking force in order to minimize the braking distance.Alternatively, braking can be achieved without a braking device by reducing the drive speed(s) to zero. The at least one braking device can be a brake provided in addition to the drive or the drive itself. Depending on the component, braking can be achieved via the drive or via an additional brake.

[0053] Preferably, the braking (reduction of the target speed) is carried out using a defined braking function, which can be defined in a controller or the control unit.

[0054] The movement of the rope exit point 16 can consist of several individual movements (e.g., rotation of the turntable 12 and swiveling movement of the boom 14), thus involving several drives (e.g., rotary drive and rocker cylinder). To determine the expected braking trajectory 20 of the rope exit point 16, an expected braking trajectory is therefore determined for each of the involved components, i.e., for each of the moving components or drives involved in the current machine movement. If only a single movement is involved, the expected braking trajectory of the corresponding component (e.g., in the case of a pure rotational movement of the turntable 12, see Figure 1) can be determined. Fig. 1 ) simply be converted into or correspond to the expected braking trajectory 20 of the rope exit point 16.

[0055] The expected braking trajectory 20 of the cable exit point 16 is determined from the predicted braking trajectories of the individual trades or components, preferably by means of a kinematic model.

[0056] The calculation of the expected braking trajectory 20 of the rope exit point 16 is preferably based on: A definition of how the control system of the machine 10 (which may be the aforementioned control unit) reduces the target speed of the actuators when stopping; the current actual speed and actual position of the machine, which are recorded via appropriate sensors and made available to the control unit; and a model of the machine that predicts the braking behavior based on the aforementioned parameters. These machine models can be built, for example, on control elements (in the simplest case, PT1). The parameterization of the machine models is based in particular on test or identification runs, in which the braking behavior of the respective machine is examined.

[0057] The kinematic model is defined in particular by static geometric parameters of the working machine 10, such as the boom length and / or the joint positions and / or the joint velocities of the slewing mechanism, the luffing mechanism, and / or the cable length. These positions and velocities are preferably converted into the coordinate system of the respective actuator in order to apply the aforementioned component models for the dynamic braking behavior. For example, in the case of the luffing mechanism, the angle of the boom 14 can be determined via a rotary encoder, while the movement itself can be executed by a hydraulic cylinder and modeled accordingly. Using the calculated braking trajectories for each component or moving part, the position and velocity of the cable exit point 16 are preferably calculated at each time step via the forward kinematics.

[0058] The kinematic model can make one or more of the following simplified assumptions: Crane structure as a rigid body; load as a point mass; ropes are massless and / or rigid; only small rope exit angles.

[0059] The previous statements regarding the trade models and the kinematic model apply regardless of the specific embodiment of the working machine 10 or the moving components involved.

[0060] In the exemplary embodiment of the Figure 1 The expected braking trajectory 20 of the rope exit point 16 is shown as a dashed line. This decelerates the rotational movement of the machine 10. At the start of the braking process, the load is located at the indicated starting position 17 (this position is offset outwards / backwards relative to the rope exit point 16 due to the rotational movement).

[0061] During the braking process, the load 18 moves along its own path 22 and then oscillates for a period of time around the stop position 19 of the rope exit point 16. This process is preferably modeled based on the determined expected braking trajectory 20 of the rope exit point 16 and using a physical model. For this purpose, the current rope length between the rope exit point 16 and the load 18 and / or the weight of the load 18 and / or a speed and / or an acceleration of the machine 10 can preferably be taken into account. Further input parameters are, of course, possible. Some or all of the aforementioned quantities can be detected by appropriate sensors on the machine 10 and transmitted to the control unit (the weight of the load 18 can, for example, be determined by a pressure measurement in at least one hydraulic cylinder and / or by detecting a rope force; the current rope length can, for example, be determined by a pressure measurement in at least one hydraulic cylinder and / or by detecting a rope force).(detected via an angle sensor of a winch).

[0062] Alternatively or additionally, parameters can be manually entered by the operator via an input unit, for example the weight of load 18 or the selection of a load type for which a specific weight is already stored.

[0063] In the Figure 1 The resulting predicted braking trajectory 22 of the load 18 is shown as a dotted line. However, this does not depict the complete predicted braking trajectory 22 until the load 18 comes to a standstill (which would spiral to the stop position 19), but only a segment. The load 18 is shown for some of the positions along the predicted braking trajectory 22. It can be seen that the load can rotate around a vertical axis during the braking process.

[0064] The physical model preferably also takes into account the geometry of the load 18, in particular its base area and preferably its volume or its overall dimensions in three-dimensional space. Alternatively or additionally, the height of a lower edge of the load 18 above the ground can be considered, which can result from a current rope length and the geometry of the load 18. It would also be possible to consider only the base area and the lower edge height of the load 18.

[0065] The geometry of the load 18 can optionally be entered by the operator using an input unit or determined by entering / selecting a load type (e.g., a specific container size). If the load 18 is a tool (for example, a gripper), its geometry can be stored in the control unit, as it does not change. Alternatively or additionally, it is conceivable to detect the geometry and / or mass of the load 18 using appropriate sensors.

[0066] Based on the determined expected braking trajectory 22 of the load 18 and the geometry of the load 18, the physical model calculates an area or volume that the load 18 is expected to occupy as it traverses the expected braking trajectory 22, due to its dynamic oscillation behavior. This results in an expected collision area within which, in the event of an assumed abrupt braking, a collision with objects whose height is above the lower edge of the load 18 could occur.

[0067] The resulting collision area depends on the assumed reaction time tR. In the Figure 1Three different expected collision areas 30, 32, 34 are shown. A first expected collision area 30, whose boundary is shown with a solid line, can be based on an average assumed reaction time tR1. A second expected collision area 32, whose boundary is shown with a dashed line, is based on a longer assumed reaction time tR2, while a third expected collision area 34, whose boundary is shown with a dashed (two dots) line, is based on an even longer assumed reaction time tR3 (i.e., tR1 < tR2 < tR3).

[0068] These anticipated collision areas 30, 32, 34 (i.e., their areas or volumes) are preferably compared with environmental data (e.g., a representative map of the machine's surroundings) to identify potential obstacles. The environmental data can be stored on a memory unit of the machine 10 or in the control unit and / or be transferable to the machine 10 from an external computer unit (e.g., wirelessly).

[0069] In the Figure 1 Three potential obstacles 40, 42 (i.e., objects that are at least partially within the work area 11 and whose height is, in particular, above the lower edge of the load 18) are shown. Two objects 40 do not overlap with any of the predicted collision areas 30, 32, 34. However, one of the objects 42 lies within the third predicted collision area 34, so a collision could occur there.

[0070] The second and third anticipated collision zones 32 and 34 can function as early warning zones, alerting the operator in time to a potential collision. Assuming that the reaction times tR2 and tR3 underlying the early warning zones 32 and 34 are above typical reaction times, the operator can initiate braking in time to prevent a collision with object 42. In contrast to the Figure 1 It is also possible to identify more or fewer early warning zones and / or larger or smaller early warning zones.

[0071] The identified potential collision zones 30, 32, 34 can be used to issue timely warnings to the operator, enabling them to react early (assistance system). Alternatively, the described procedure could be used within the framework of autonomous machine control.

[0072] Alternatively or in addition to a warning to the operator in the event of a detected potential collision, automatic intervention in the machine control can also take place (e.g. to initiate immediate braking or to modify a current machine movement and thus possibly avoid an obstacle if timely braking is no longer possible).

[0073] In the Figure 2 A schematic representation of an embodiment of the method according to the invention and the various influencing factors / steps is shown.

[0074] It can be seen that for each component / assembly involved in the movement of the load 18, a predicted braking trajectory is calculated based on an assembly model. As input parameters, each assembly model can receive the current assembly or actuator position detected by sensors, the current assembly or actuator speed detected by sensors, further assembly parameters (e.g., the geometry and / or mass of the moving component), and / or an associated, defined braking function (i.e., a definition of how the control system reduces the target speed of the assembly or actuator when stopping).

[0075] Based on the expected braking trajectories of the trades or moving components and other parameters of the working machine 10, a kinematic model calculates an expected braking trajectory of the defined point 20, in particular the cable exit point 16.

[0076] Based on this calculated braking trajectory and further parameters relating to the suspended load 18 (in particular its dimensions and / or mass) and the rope (in particular its rope length between the load's center of gravity and the rope's exit point 16), a physical model calculates a predicted braking trajectory of the load 22. The physical model takes into account the current load position and load speed and / or the current rope position and rope angular velocities.

[0077] Furthermore, the kinematic model can be designed to determine and incorporate a predicted braking trajectory of the rope. This trajectory can be the rope length between the defined point (in particular, rope exit point 16) and the rope end, i.e., the rope length over time until all components come to a standstill. Reference symbol list:

[0078] 10 Working machine 11 Working area 12 Rotating platform 14 Boom 16 Rope exit point 17 Starting position of the load 18 Load 19 Stop position 20 Expected braking trajectory of the defined point 22 Expected braking trajectory of the load 30 Expected collision area 32 Expected collision area 34 Expected collision area 40 Object outside the collision area 42 Object inside the collision area

Claims

1. Method for collision monitoring of a load (18) which is attached to a cable of a working machine (10), in particular a crane, wherein the working machine (10) comprises a rotating platform (12) rotatable about a vertical axis of rotation, a boom (14) connected to the rotating platform (12) over which the cable is guided, and at least one sensor for detecting a current position and / or movement of at least one movable component of the working machine (10), characterized by that Based on the sensor data, a predicted braking trajectory (20) of a defined point of the working machine (10) is determined, and based on the determined braking trajectory (20) of the defined point and a computational model, a predicted braking trajectory (22) of the load (18) is calculated.

2. Method according to claim 1, wherein the defined point is a point on the boom (14), in particular a rope exit point (16), wherein the rope exit point (16) is preferably located at a boom head.

3. Method according to claim 1 or 2, wherein the expected braking trajectory (20) of the defined point is determined based on at least one expected braking trajectory of a movable component of the working machine (10), preferably based on a combination of at least two expected braking trajectories of different movable components of the working machine (10).

4. Method according to one of the preceding claims, wherein the expected braking trajectory (20) of the defined point is determined using a kinematic model of the working machine (10), in particular using a kinematic model of at least two movable components of the working machine (10).

5. Method according to one of the preceding claims, wherein the expected braking trajectory (22) of the load is determined using a physical model, wherein the model in particular takes into account the behavior of the rope during movement of the working machine (10) and / or the weight of the load (18) and / or a geometry of the load (18) and / or a rope length and / or a wind speed.

6. Method according to one of the preceding claims, wherein at least one dimension of the load (18), preferably a height, an area and / or the volume of the load (18), is computationally combined with the determined expected braking trajectory (22) of the load in order to determine an expected collision area (30, 32, 34) which the load (18) occupies when passing through the braking trajectory (22).

7. Method according to the preceding claim, wherein the determined probable collision area (30, 32, 34) is compared with environmental data of the working machine (10), wherein the environmental data relates to objects (40, 42) located in an environment of the working machine (10), wherein the comparison preferably includes a check to see if the determined probable collision area (30, 32, 34) overlaps with an object (40, 42) in the environment, wherein in the event of a determined probable collision a warning is issued and / or the control of the working machine (10) is automatically intervened.

8. Method according to one of the preceding claims, wherein the expected braking trajectory (22) of the load (18) is determined assuming a reaction time between a stop signal and the initiation of braking of the working machine (10), wherein preferably at least two different expected braking trajectories (22) of the load are determined based on different assumed reaction times, and wherein, in particular, for each of the different expected braking trajectories (22), an expected collision area (30, 32, 34) is determined and compared with environmental data.

9. Method according to one of the preceding claims, wherein the calculation of the expected braking trajectory (22) of the load (18) is carried out at regular intervals during the operation of the working machine (10).

10. Working machine (10), in particular crane, comprising a rotating platform (12) rotatable about a vertical axis of rotation, a boom (14) connected to the rotating platform (12) over which a rope is guided, and a control unit which receives data from at least one sensor of the working machine (10) relating to a current position and / or movement of a load (18) suspended on the rope, characterized by that the control unit is configured to carry out the procedure according to one of the preceding claims.

11. Working machine (10) according to the preceding claim, comprising an input unit connected to the control unit, via which at least one dimension, in particular a volume, of the attached load (18) and / or a load type can be manually entered.

12. Working machine according to claim 10 or 11, comprising an output unit, in particular a monitor, wherein the control unit is configured to display on the output unit, in particular graphically, a determined expected braking trajectory (20) of the defined point and / or a calculated expected braking trajectory (22) of the load (18) and / or an expected collision area (30, 32, 34) occupied by the load (18) when passing through the braking trajectory (22).

13. Working machine according to one of claims 10 to 12, comprising a storage unit on which environmental data relating to objects (40, 42) located in an environment of the working machine (10) are stored, wherein the control unit has access to or includes access to the storage unit.

14. Computer program product comprising instructions which, when the program is executed, cause the steps of the method according to one of claims 1 to 9 to be executed by the control unit of the working machine (10) according to one of claims 10 to 13.

Images