EP3733586A1 - Method for collision-free movement of a load with a crane - Google Patents

Abstract

The invention relates to a method for the collision-free movement of a load (4) with a crane (2) in a space with at least one obstacle (18). In order to meet a safety level in the simplest possible way, it is proposed that a position of the obstacle (18) be provided, with at least one safe state variable of the load (4) being provided, a safety zone surrounding the load (4) from the safe state variable (20) is determined, the safety zone (20) being monitored dynamically in relation to the position of the obstacle (18).

Description

The invention relates to a method for the collision-free movement of a load with a crane in a room with at least one obstacle.

The invention also relates to a controller for carrying out such a method.

The invention also relates to an autonomous, safe observer module for collision detection which has such a controller.

In addition, the invention relates to a system with a crane for moving a load which comprises such an observer module.

In the crane environment, for example in the port area, when loads, for example containers, are loaded and unloaded, collisions between a load, in particular a rope-guided load, with an obstacle, also called an object, can occur again and again. With a manually operated crane, full responsibility for the crane and the load it guides rests with the crane operator. He must ensure that there is no collision with another object.

In the case of an automated crane, the load, in particular rope-guided, is guided through a 2D or 3D space with at least one obstacle with the aid of sensors, with hardware and software solutions ensuring that no collision occurs. For example, systems such as sway control, also known as "sway control", path calculation in 2D or 3D space and systems for the detection of obstacles and disturbances are used.

To fully certify such a solution with several systems in terms of safety technology represents a considerable effort, since each of the subsystems has to be individually certified in terms of safety technology. Safe functioning of the overall system is only guaranteed if all subsystems meet the safety-relevant requirements.

For example, the laid-open specification describes WO 2005/049285 A1 a system for vibration control. The system includes a first device connected to measure an acceleration of a first object suspended from a second object, the first device generating a first signal representative of the acceleration of the first object; a second device connected to measure an acceleration of a second object, the second device generating a second signal representing the acceleration of the second object; a processor in connection with the first and second devices, which is configured to determine an oscillation of the first object with respect to the second object on the basis of at least partially the first and second signals, the oscillation a relative displacement of the first object with respect to the second Object represents.

In the case of route planning in real time, a so-called "real-time route planning", in 2D / 3D space, simplifications in the algorithms would be required, which represent a considerable effort in terms of proving a safe function for a security certification. With systems like "Sway-Control" attempts are made to achieve a security certification through redundancy.

The disclosure document WO 2018/007203 A1 describes a method for preventing a load of a crane from colliding with an obstacle. In order to specify a solution for collision avoidance that fulfills a safety level, a solution is proposed in which the load is moved along a trajectory, using at least two sensors Distance measurement, a height profile is detected at least along the trajectory, with signals from the sensors being sent via at least two communication channels to a controller with at least two operating systems, at least one of which has a security program in a safe area, with an obstacle being detected along the trajectory based on the height profile becomes. The controller also has a secure communication interface for transmitting signals from the controller to a crane control.

The invention is based on the object of specifying a method for the collision-free movement of a load with a crane which fulfills a safety level in the simplest possible way.

The object is achieved according to the invention by a method for the collision-free movement of a load with a method for the collision-free movement of a load with a crane in a space with at least one obstacle, a position of the obstacle being provided, with at least one safe state variable of the load being provided, a safety zone surrounding the load is determined from the safe state variable, the safety zone being monitored dynamically in relation to the position of the obstacle.

Furthermore, the object is achieved according to the invention by a controller for carrying out such a method, which includes a safety program in a safe area.

In addition, the object is achieved according to the invention by an autarkic, safe observer module for collision detection which has such a controller.

In addition, the object is achieved according to the invention by a system with a crane for moving a load, which system comprises such an observer module.

The advantages and preferred refinements listed below with regard to the method can be applied analogously to the controller, the observer module and the system.

The invention is based on the idea of providing a self-sufficient, safe observer module for collision detection in order to supplement a sensor-supported load movement by an automatically operated crane system, which in itself has a high level of reliability but is not certified in terms of safety. Such a collision detection ensures a safety level according to SIL and / or PL, e.g. at least SIL3 and / or PLe, achievable without having to certify the actual crane system in terms of safety.

A position of an obstacle is provided. For example, a load position is provided via suitable sensors, in particular laser distance sensors. In addition, at least one safe state variable of the load that is moved by the crane is provided. A state variable is, for example, a position of at least one movement axis, a speed or an acceleration. A safe state variable of the load is provided for example by safe encoder systems, in particular at least certified according to SIL and / or PL, and / or by redundant encoder systems. On the basis of the at least one safe state variable of the load, a safety space is calculated, which is monitored in relation to the determined position information of the obstacle. For example, the safety space is spherical or ellipsoidal and at least partially surrounds the load. If this safety area is violated, for example, a countermeasure is initiated to prevent a collision.

Such a method can be described with a very simple mathematical model and implemented with little computing effort will. A security certification described above is enormously simplified. Another advantage is that the systems used for sensor-supported load movement in automated crane operation, such as "sway control" and path calculation, can still be used as a non-safe system for movement control. The self-sufficient, safe observer for safe collision detection, which is designed in particular as at least one module, supplements a system with high reliability, which, however, is classified as not safe, to form a safe overall system. The self-sufficient, safe observer module, which works according to the method described above, ensures safe automated crane operation regardless of the systems used for automated crane operation.

In a preferred embodiment, a safe position of the obstacle is detected, in particular by means of sensors for distance measurement. Sensors for distance measurement are, for example, laser or radar sensors. Safe position detection is achieved, for example, with the help of safe sensors for distance measurement, in particular certified according to SIL and / or PL. Reliable detection of the position of the obstacle increases the reliability of the method.

In a further advantageous embodiment, the at least one safe state variable of the load is determined from a safe state variable of at least one chassis, a hoist and / or a trolley of the crane. Corresponding safe encoder systems, which are certified according to SIL and / or PL, for example, are commercially available.

A stop signal is particularly advantageously sent to a crane control when the obstacle is detected in the safety zone surrounding the load. A crane stop triggered by a stop signal simply and reliably prevents a collision.

In a preferred embodiment, a size of the safety zone is adapted to the safe state variable of the load. The size of the safety zone is defined in particular by a volume. For example, the volume of the safety zone is increased as the speed or acceleration of the load increases in order to compensate for a longer delay time in the event of a countermeasure. In this way, a collision is prevented even more reliably.

In a further advantageous embodiment, the safety zone is determined with a controller that includes a safety program in a safe area. The safety program in the safe area can be implemented, for example, through redundancy, multiple channels and / or internal checking and test algorithms, whereby a safety certification, e.g. according to SIL and / or PL, can be implemented.

It is particularly advantageous if the safety program sends a safe stop signal to a crane control when the obstacle is detected in the safety zone surrounding the load. This defines a safety area surrounding the load, within which the crane is immediately and safely stopped if an obstacle occurs.

In a preferred embodiment, the safe state variable of the load includes a position and a speed and / or an acceleration. For example, a speed and / or an acceleration is determined by differentiation from a change in the position. By knowing the position and the speed and / or the acceleration of the load, the reliability of the monitoring of the load is optimized.

The security zone is particularly advantageously determined in real time. A determination in real time is achieved by simple mathematical models, which enables a reliable reaction to changes in the position of the obstacle. In a preferred embodiment, the safety zone is determined periodically at time intervals that depend on the safe state variable of the load. For example, the time intervals are shorter at a higher speed of the load in order to react to a longer braking distance. Such state variable-dependent intervals enable a reliable reaction to changes in the system.

In a further advantageous embodiment, the safety zone is determined using a pendulum model. The pendulum model models, for example, a load swinging out in the event of an abrupt deceleration, so that in such a case, for example, the safety zone is enlarged to prevent a collision.

The method can particularly advantageously be carried out independently of the movement of a load. The method is thus not influenced by crane operation, for example by errors that occur during operation, which leads to an improvement in reliability.

In a further advantageous embodiment, a height profile for determining the position of the obstacle is created with the aid of sensors for distance measurement. If the crane is e.g. around a container crane, which unloads containers as loads in a container terminal, the stacking heights of the containers as a height profile, as it were, result in a mountain of containers. Such a height profile facilitates the calculation of the trajectory for the automated movement of the load by means of the crane.

FIG 1

eine perspektivische schematische Darstellung eines Krans,

FIG 2

eine vergrößerte schematische Darstellung eines Krans im Bereich einer Last,

FIG 3

eine schematische Darstellung einer kollisionsfreien Bewegung einer Last von einem Startpunkt zu einem Zielpunkt und

FIG 4

ein Ablaufdiagramm eines Verfahrens zur kollisionsfreien Bewegung einer Last.

The invention is described and explained in more detail below using the exemplary embodiments shown in the figures.

FIG 1

a perspective schematic representation of a crane,

FIG 2

an enlarged schematic representation of a crane in the area of a load,

FIG 3

a schematic representation of a collision-free movement of a load from a starting point to a target point and

FIG 4

a flowchart of a method for collision-free movement of a load.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another, which also develop the invention independently of one another and are therefore also to be regarded as part of the invention individually or in a combination other than the one shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

The same reference symbols have the same meaning in the various figures.

FIG 1 shows a perspective view of a crane 2, which is exemplified as a bridge crane. A load 4, for example a container, which is attached to a container harness 6, also called a "spreader", is conveyed by means of a trolley 8, also called a "trolley", by means of a chassis 10 and / or by means of a hoist 12 along a, in particular three-dimensionally executed, trajectory 14 moves. The movement of the load 4 by means of the crane 2 is particularly automated. A safe position of an obstacle 18, in FIG 1 a "container mountain", recorded by creating a height profile. Alternatively, a known position of the obstacle 18 provided. In particular, a safe position of the obstacle 18 is determined by at least SIL- and / or PL-certified sensors. Such at least SIL- and / or PL-certified sensors 16 for distance measurement work, for example, with radar and / or laser methods. In particular, the sensors 16 for distance measurement are redundant. The secure position detection of the obstacle 18 takes place in particular dynamically, for example by periodically updating the height profile. The obstacle 18 prevents the load 4 from being able to be transported to its destination in a direct, that is to say straight, path. A trajectory 14 is therefore calculated on the basis of the height profile in order to overcome the obstacle 18, for example in a parabolic movement. Swinging of the load 4 while it is being moved along the trajectory 14 is minimized by sway damping, also called "sway control", in order to avoid collisions or damage to the load and / or to increase load transport efficiency.

FIG 2 shows an enlarged schematic representation of a crane 2 in the area of a load 4 that is moved over an obstacle 18. In order to ensure a collision-free movement of the load 4, the crane 2 includes an autonomous, safe observer module for collision detection, to which a safe state variable of the load 4 is transmitted, the safe state variable being a position, a speed or an acceleration of the load 4 includes. For example, a safe position of the load 4 is determined via a safe, in particular at least according to SIL and / or PL-certified, encoder system on the trolley 8, on the chassis 10 and on the hoist 12, with a speed and / or an acceleration of the load 4 can be calculated directly from a change in the safe position.

The self-sufficient, safe observer module calculates in a safe controller in real time from at least one safe state variable, for example from a position and a speed, a safety zone surrounding the load 4 20. For example, the safety zone 20 is calculated periodically at time intervals depending on the safe state variable of the load 4. A safe controller includes a safety program in a safe area. The security zone 20 is, for example, as in FIG FIG 2 to see, spherical or ellipsoidal. In particular, a size of the safety zone 20 is adapted to a safe state variable of the load 4, for example to a speed or an acceleration. For example, the volume of the safety zone 20 is increased when the speed or the acceleration of the load 4 is increased. Optionally, a pendulum model is included in the calculation of the safety zone 20 in order, for example, to take account of the load 4 swinging out in the event of an abrupt deceleration.

The position of the obstacle 18 is reliably detected as in FIG FIG 1 described. The self-sufficient, safe observer module dynamically monitors the safety zone 20 in relation to the position of the obstacle 18. For example, a stop signal is sent to a crane control when the obstacle 18 in the safety zone 20 surrounding the load 4 is detected. The further version of the crane 2 in FIG 2 corresponds to the in FIG 1 .

FIG 3 shows a schematic representation of a collision-free movement of a load 4 from a starting point 22 to a target point 24, the load movement being carried out, in particular automatically, with the aid of a crane 2. The load movement from a container ship 26 as starting point 22 to a truck 28 as destination point 24 is shown by way of example, the obstacle 18, which is designed as a "container mountain", as shown in FIG FIG 1 is overcome in a parabolic movement along a, in particular precalculated, trajectory 14. In order to ensure a safe collision-free movement, the crane 2 comprises an autarkic, safe observer module 19 for collision detection, which, as in FIG 2 , in a secure controller 19a, the safety zone 20 surrounding the load 4 is calculated in real time. The size the safety zone 20, which surrounds the load 4, is adapted, for example, to a speed and / or an acceleration. The temporal change in the volume of the security zone 20, shown as an example in the form of a sphere, is shown schematically in FIG FIG 2 for a given obstacle 18, the trajectory 14, as in FIG FIG 1 , is calculated based on the determined height profile of the obstacle 18. The further version of the crane 2, in particular the self-sufficient, safe observer module, in FIG 3 corresponds to the in FIG 2 .

FIG 4 shows a flow chart of a method for the collision-free movement of a load 4. The automated movement 28 of the load 4 takes place with high reliability by means of pendulum damping 30, geometric calculation 32 of the trajectory 14, disturbance variable monitoring 34 and, in particular dynamic, object detection 36 the detection of the position of the obstacle 18 takes place as in FIG FIG 1 described, safe, in particular using a height profile through at least SIL and / or PL-certified sensors.

A safe state variable acquisition 38 of the load 4 takes place in parallel as in FIG FIG 2 described, for example by a safety-certified encoder system on the trolley 8, on the chassis 10 and on the hoist 12, for example according to SIL and / or according to PL. An independent, safe observer module 40 performs a safety zone calculation 42 based on the determined safe state variable. Dynamic room monitoring 44 takes place in that the safely detected safety zone 20 is monitored in relation to the safely detected position of the obstacle 18. A safe stop 46, for example by sending a stop signal to a crane control, is initiated by the self-sufficient, safe observer module 40 when the obstacle 18 in the safety zone 20 of the load 4 is detected.

In summary, the invention relates to a method for the collision-free movement of a load 4 with a crane 2 in one Room with at least one obstacle 18. In order to meet a safety level in the simplest possible way, it is proposed that a position of the obstacle 18 be detected, with at least one safe state variable of the load 4 being determined, with one surrounding the load 4 from the safe state variable Safety zone 20 is determined, the safety zone 20 being monitored dynamically in relation to the position of the obstacle 18.

Claims (15)

Method for the collision-free movement of a load (4) with a crane (2) in a room with at least one obstacle (18),
wherein a position of the obstacle (18) is provided,
at least one safe state variable of the load (4) being provided,
a safety zone (20) surrounding the load (4) being determined from the safe state variable,
wherein the safety zone (20) is dynamically monitored in relation to the position of the obstacle (18). Method according to claim 1,
a safe position of the obstacle (18) being detected, in particular by means of sensors (16) for distance measurement. Method according to one of Claims 1 or 2,
wherein the at least one safe state variable of the load (4) is determined from a safe state variable of at least one chassis (10), a hoist (12) and / or a trolley (8) of the crane (2). Procedure according to one of the previous,
wherein a stop signal is sent to a crane control when the obstacle (18) is detected in the safety zone (20) surrounding the load (4). Method according to one of the preceding claims,
wherein a size of the safety zone (20) is adapted to the safe state variable of the load (4). Method according to one of the preceding claims,
wherein the safety zone (20) is determined with a controller (9a) which comprises a safety program in a safe area. Method according to claim 6,
wherein the safety program sends a stop signal to a crane control when the obstacle (18) is detected in the safety zone (20) surrounding the load (4). Method according to one of the preceding claims,
wherein the safe state variable of the load (4) comprises a position and a speed and / or an acceleration. Method according to one of the preceding claims,
wherein the security zone (20) is determined in real time. Method according to one of the preceding claims,
wherein the safety zone (20) is determined periodically at time intervals dependent on the safe state variable of the load (4). Method according to one of the preceding claims,
wherein the safety zone (20) is determined with a pendulum model. Method according to one of the preceding claims,
which can be carried out independently of the movement of a load (4). Controller (19a) for carrying out a method according to one of Claims 1 to 12, which comprises a safety program in a safe area. Autonomous, safe observer module (19, 40) for collision detection, which has a controller (19a) according to Claim 13. System with a crane (2) for moving a load (4), which system comprises an observer module (19, 40) according to Claim 14.

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