EP3894349B1 - Container-loading system and method for monitoring operation therein - Google Patents

Description

Field of invention

The invention relates to a container loading system and a method for operational monitoring with the features of the preambles of the independent claims.

Technical background

In a container terminal, a container bridge (STS (Ship-To-Shore) Crane) loads standardized ISO containers from the ship to land, either directly onto trucks, or it transfers the containers to transport vehicles, in particular automated guided vehicles (AGV). Guided Vehicle), which are often designed as straddle carriers and automatically pick up the containers and drive them to a destination. The area on which the AGVs drive is closed to people for safety reasons.

The destination can e.g. This could, for example, be a land-based interim storage facility in which rail-mounted gantry cranes (RMG; Rail Mounted Gantry) or rubber-tired gantry cranes (RTG; Rubber Tired Gantry) unload containers for interim storage.

There are transfer lanes inside or outside the portal through which containers are delivered or picked up. The handover takes place under manual crane control by a crane operator.

Vehicles for the road transport of containers are available as trucks with or without a trailer, as well as articulated vehicles consisting of a truck tractor and a container chassis attached like a normal semi-trailer, or as terminal trucks with a terminal trailer. In the case of a loading order for road transport, the driver or another person must walk around the vehicle and unlock the twistlocks on the vehicle before or after loading or unloading lock. When loading a terminal trailer, the driver must check whether the so-called IBCs (Inter Box Connectors, which hold containers together on a ship) have been removed. People can move freely in the space below the crane.

The DE 10 2006 044187 A1 discloses a container loading system and a method with the features of the preambles of the independent claims.

The EP 2 724 972 B1 discloses a container loading system and a method for the computer-aided determination of the position in which an ISO container is to be placed on a carrier vehicle using a crane, based on a cloud of measuring points representing the top of the carrier vehicle, which is obtained by scanning the carrier vehicle from above from a height of at least 5 meters can be obtained with a 3D laser scanner or two 3D laser scanners mounted at a distance. The proposed 3D laser scanner is formed from a 2D laser scanner, which can be pivoted using a servo motor and is here a time-of-flight infrared laser scanner with a distance resolution of approximately 10 mm. This resolution is required to identify and locate twist locks on the carrier vehicle and to be able to calculate container target position data from this.

Such 3D laser scanning provides an essentially complete image of the measurement scene in the form of relatively dense three-dimensional point clouds.

This and other processes now make it possible to largely automate the crane work in truck handling, but it is essential that occupational safety is guaranteed, which has so far been the case, for example. B. is achieved by the crane operator being in the work area such as. B. maintains radio contact with a truck driver and can give and receive instructions.

Camera-based systems with image analysis can be used to monitor the danger area for people who are in it during the automatic loading or unloading of road transport vehicles in order to trigger an alarm or emergency stop if necessary. Due to inadequacies of such systems or e.g. However, due to restricted visibility and/or adverse weather conditions, false positive or false negative hazard detections can occur, resulting in personal injury and corresponding downtime. Therefore, it is It would be desirable to be able to recognize and locate people in the work area in at least one additional way and thus ensure special redundancy.

In principle, you could also see in the measurement point cloud of a 3D laser scanner for determining the position of containers and trucks whether there is something in the way that doesn't belong there, but the time it takes to obtain such a relatively high-resolution scan is , several orders of magnitude too long to be able to detect the presence of people in the work area, especially if they are moving. In particular, the 3D laser scanners used so far have to be rotated as a whole from one position to the next, where they stop briefly in order to obtain a cutting profile. At best, one could consider using a large number of individual 3D laser scanners, each of which only looks at a small section of the scene, but such a thing would multiply the equipment and computational effort.

Brief description of the invention

The invention is based on the object of improving occupational safety when loading containers with acceptable effort.

This task is solved by a container loading system and a method with the features specified in the independent patent claims. Advantageous developments of the invention are specified in the dependent claims.

According to the invention, the laser scanners are of a type adapted to scan the work surface simultaneously in several spaced planes or lines, emitting a fan of diverging planes of light beams or a fan of diverging individual light beams. At the height of the work surface, the planes or lines are at a distance from one another that is in at least one direction on the floor, e.g. B. in the longitudinal direction of the loading position and / or transversely to it, is larger than 10 and smaller than 30 centimeters.

There is also a person recognition unit that is set up to scan the laser scanner(s) at least once during a container loading process to be carried out in order to obtain a measurement point cloud; in the measurement point cloud obtained in this way, e.g. B. to identify the work area and the loading area of the road transport vehicle by averaging and/or eliminating outliers; to determine whether in the measurement point cloud there is at least one or, in a preferred embodiment, at least two adjacent measurement points located more than 0.5 meters or alternatively more than 1 meter above the identified work surface or the identified loading area, and if there is at least one such measurement point to output a person probable signal, which indicates that there is probably a person at the corresponding location.

There is also a safety device designed to slow or stop the crane movement when the person-probable signal is issued, whereby a warning signal can be issued first or in addition.

In a preferred embodiment, each of the laser scanners is a 3D multilayer scanner. Such a scanner, also called a 3D multi-level scanner or 3D multi-layer scanner, is commercially available and is e.g. B. in the EP 2 983 030 A2 described, which reveals that in many applications there is a desire to capture the environment in more than just a single plane, especially in mobile applications, such as driverless vehicles, where there is a requirement to recognize the ground with edges and shoulders as well as objects , which protrude into the driving area at different heights. Instead of using three-dimensional scanners in which the sensor as a whole or the rotating mirror is also periodically tilted, it is sufficient if not an entire area of space can be monitored, but only a few layers layered on top of each other.

The invention includes the new purpose of multilayer laser scanners, not to use them to detect objects that lie more or less horizontally in front of the scanner by layering the scanning planes on top of each other, but rather to detect people who are more or less vertically below the scanner, in container handling zones, with the scanning levels stacked next to each other. Unlike conventional 3D laser scanning, you only get an incomplete image of the measurement scene, which is possible if the distances are chosen appropriately However, between the levels is sufficient to recognize whether there is probably a person in the measurement scene or not, and this image of the measurement scene is obtained in a very short time, which is at most in the order of 1/10 of a second and often much less , so that the detection of moving people is also possible.

As an alternative to multilayer laser scanners, so-called 3D array scanners or flash LiDAR devices can also be used for the invention. Such devices have an array of laser diodes that simultaneously emit a fan of diverging individual light beams, whereby a complete 3D image is immediately available.

In preferred embodiments, a z. B. a 2 x 2 meter person stay zone is marked on the work surface, and the safety device only allows crane movements if a person probable signal is issued for the person stay zone, but not for the rest of the work area, thereby detecting that there are people in the person stay zone, but there is no person in the rest of the work area.

In preferred embodiments, the work surface is divided into several zones, namely at least one inner zone which includes at least the loading position, i.e. H. either equal to or greater than the loading position, and an outer zone extending around and adjacent to the inner zone. During a container loading process, several consecutive scans are carried out and if at least one measuring point is more than 0.5 meters (or alternatively more than 1 meter) above the identified work surface or the identified loading area, a person probable signal is issued .

In addition, it is checked whether the location of such a measuring point in the measuring point cloud changes over time. If so, a moving person probable signal can be issued.

Depending on which of the two zones which of the two types of signals are issued, the crane movement is slowed down or stopped. Included The location and size of the zones into which the work area is divided can be dynamically changed during operation of the system and adapted to the location and direction of movement of a container that has just been loaded.

Unlike conventional safety and collision avoidance systems, an emergency stop does not have to take place immediately, but a gradual reaction can take place, e.g. B. initially a mere warning when it is detected that a person is approaching the outer zone, then a slower operation of the crane when the person enters the outer zone, and an emergency stop only when the person enters the inner one Zone enters.

In the method for operational monitoring of a work area on a floor below a container crane, one or more 3D laser scanners being used from a height above the floor that exceeds the height of an ISO container by several times during a container loading, setting down or lifting process the work surface can be scanned in three dimensions from above, according to the invention the laser scanner or scanners are scanned the work surface with a fan of diverging planes of light beams or a fan of diverging individual light beams simultaneously in several spaced-apart planes or lines in order to achieve a To obtain a measurement point cloud, the planes or lines at the height of the work surface being at a distance from one another which is dimensioned such that a person standing on the work surface is hit by at least one plane of light rays or at least one of the individual light rays. The work area is first identified in the measurement point cloud obtained in this way. It is then determined whether there are at least one or more measurement points in the measurement point cloud that are typical for a person standing on the identified work surface. If there is one or, in preferred embodiments, at least two adjacent such measuring points, the crane movement is slowed or stopped.

In preferred embodiments, crane movements are not slowed down or stopped, but remain permitted if one or more measuring points typical of a person standing on the identified work surface are for a predetermined area at the edge of the work surface, but not for a central one Area of the work surface can be determined.

In preferred embodiments, a plurality of zones are defined within the work surface, namely at least an inner zone directly below a container hanging on the crane and an outer zone extending around and adjacent to the inner zone. Crane movements are only permitted if one or more measuring points that are typical of a person standing on the identified work area are not determined in the inner or outer zone. Crane movements are slowed down if one or more measuring points typical of a person standing on the identified work surface are determined in the outer zone and not in the inner zone. Crane movements are stopped when one or more measuring points typical of a person standing on the identified work surface are detected in the inner zone.

Further features and advantages of the invention result from the dependent patent claims and from the following description of exemplary embodiments based on the drawings.

Brief description of the drawings

Fig. 1

shows a schematic side view of a lower part of a rail-mounted gantry crane, in which a work surface is located at the floor of a work space to be monitored;

Fig. 2

shows a schematic top view of the work surface of Fig. 1 ;

Fig. 3

shows a schematic top view of a work area under a container crane with dynamically changing zones; and

Fig. 4

shows a flowchart of a method for monitoring the operation of a work area below a container crane.

Detailed description

Human activity is required for the loading of goods in the area (portal) of a ship-to-shore crane (STS crane) in container ports. This can e.g. B. Be a signaller for trucks, or people who remove the so-called IBCs (Inter Box Connectors, which hold containers standing on top of each other on a ship together) from the containers before they are placed on the ground or on a truck chassis. These people can move freely in the portal area. Limited visibility, carelessness and/or adverse weather conditions can result in personal injury and therefore downtime when setting down or picking up the load.

To prevent accidents involving people, a redundant system for object detection and tracking in a defined workspace is proposed. In this way, the whereabouts of every person in the danger area can be determined and, in the event of danger, for example. B. the hoist function of the crane can be stopped. The system is able to detect and locate people in the work area while containers are being loaded and continuously return their position to the crane control.

Fig. 1 shows a lower part of a container crane, here an RMG gantry crane 1, which can travel on rails on a floor 2 of a port or other container handling point and which forms a loading facility or part of it. Below the gantry crane 1 there is a work surface 3 on the floor 2, which is in Fig. 2 is shown from above, to the same scale as in Fig. 1 . On the work surface 3 there is at least one elongated loading position 4 ( Fig. 2 ) marked for a truck 5 or the like. The truck 5 has a loading area 5a and a driver's cab 5b.

Alternatively, the container crane can also be an RTG crane or an STS crane.

The work area to be monitored, in which people can and may stay, can e.g. B. be a cuboid, which is delimited by the floor 2 and by two vertical supports 6, 7 and cross beams 8 of the gantry crane 1. For example, with vertical supports 6, 7 that are far apart, the work space to be monitored can also be smaller and extend above a work surface 3, that doesn't quite reach the supports, such as: Am Fig. 2 , which the situation of Fig. 1 on the same scale in plan view.

In the exemplary embodiment, the working surface 3 extends between the vertical supports 6, 7 of the gantry crane 1. With other types of container cranes, such as a so-called cantilever RMG crane, which deposits containers over the side, or with an STS crane, the The work surface can also be completely or partially outside the crane supports, in the case of an STS crane in its so-called backreach area.

At a height above ground 2 that is several times the height of an ISO container as in Fig. 1 as a container 9 coming from above is indicated, two 3D laser scanners 10 are mounted, which are set up to monitor the work area by scanning the work surface 3, including the truck 5 standing on it, in three dimensions from above.

In particular, there is a 3D laser scanner 10 at a height of z. B. 10 or 20 meters close to a front left vertical support 6 and to a rear right vertical support that comes from the in Fig. 1 visible front right vertical support 7 is covered, i.e. close to two diagonal vertical supports 6, 7, so that the 3D laser scanners 10 lie vertically above two diagonal corners of the work surface 3, as in Fig. 2 indicated. The two 3D laser scanners 10 are further apart than the diagonal of the marked loading position 4 measures.

The laser scanners 10 are each a 3D multilayer scanner or alternatively a 3D array scanner or flash LiDAR device. The laser scanners 10 can - as in this exemplary embodiment - be expediently attached to the crane, but embodiments are also possible in which the laser scanners are attached to pillars or light poles, which can already be present on the company premises, provided they are close enough to the work area lie and do not hinder the crane's operation. In any case, the laser scanners 10 will scan the work surface 3 predominantly not exactly from above, but more or less obliquely from above.

The laser scanners 10 are also designed and oriented so that they cover the entire work surface 3 - with the exception of those between the levels or lines of the Laser scanner 10 existing gaps - can fully monitor, each of the two laser scanners 10 being responsible for one of two L-shaped subzones 11, 12, which complement each other to form a rectangle corresponding to the work surface 3 around the loading position 4. This avoids shading of parts of the work surface 3 by the truck 5 or a container 9 standing on it or hanging vertically above it. In the case of 3D multilayer scanners, the scanning planes preferably run parallel to the longitudinal direction of the loading position 4.

The loading system described above can also use another crane instead of the gantry crane 1, such as. B. have a container bridge, which transports containers from the ship directly to the truck or vice versa. In such a case, truck lanes and truck loading positions can run across the quay or in the longitudinal direction.

In the operation of the in Figures 1 and 2 In the container loading system shown, a person recognition unit allows the laser scanner 10 to continuously carry out scans during a container loading process, e.g. B. one every second or every tenth of a second. In principle, a measurement point cloud in which the floor 2 or the work surface 3 and the loading area 5a of the truck 5 are identified is sufficient.

This could be done computationally in a number of ways that are fundamentally equivalent. So one could view all measuring points that lie outside the previously known outline of the loading position 4 as forming the work surface 3, and the loading area 5a of the truck 5 is then obtained by selecting only those measuring points lying within the outline of the loading position 4, which are at a typical height above the ground 2, i.e. about 1 meter above the ground 2. This also eliminates measuring points that come from the driver's cab 5b of the truck 5. Alternatively, the work space could be divided into many virtual cuboids with dimensions adapted to the resolution of the laser scanner 10, and the tops of all cuboids into which a measuring point falls are then taken as the profile of the bottom of the work surface 3 and the loading area 5a of the truck 5 , after eliminating cuboids that easily represent the driver's cab 5b.

It is then determined whether there is at least one more than one in the measurement point cloud There is a measuring point 0.5 meters above the identified work surface or the identified loading area, or equivalently, whether there is a top cuboid that protrudes more than 0.5 meters above it. Instead of a minimum height of 0.5 meters, you could also use a different minimum height from which measuring points are taken into account, e.g. B. 0.7 or 1 meter.

If there is such a measurement point or cuboid, a person probable signal is output, which indicates that there is probably a person at this location. In addition, an object probable signal can be output if there is a measuring point or cuboid that is less than 0.5 meters, but e.g. B. is more than 30 centimeters above the identified work surface or the identified loading area, since in this case there is probably an object on the floor or on the loading area that does not belong there and e.g. B. represents a tripping hazard or an obstacle to setting down.

If a person probable signal or object probable signal is issued, a safety device ensures that the crane movement stops and sends a request to a control station or to the crane operator and/or to the truck driver to clarify the situation .

In this exemplary embodiment, the truck driver is therefore not allowed to be on the work surface 3 so that loading can be carried out quickly. However, it may be in the driver's cab 5b of the truck 5 or outside the work area 3.

In a further development of this exemplary embodiment or of the exemplary embodiments described below, the driver is or is encouraged to go to a personal stay zone 13 measuring approximately 2 x 2 meters before the loading process, which is marked on the floor in a corner of the work surface 3, as in Fig. 2 illustrated. The crane activity is only permitted as long as it is recognized by the laser scanner 10 that there is probably a person in the people's stay zone 13, but not on the work surface 3 or on the loading area 5a of the truck 5.

In a further development of this exemplary embodiment or described below Embodiments additionally determine whether there are at least one or more measuring points in the measuring point cloud that are typical for the truck 5 and in particular for its driver's cab 5b and whose locations in the measuring point cloud change over time. This shows that the truck 5 is moving during a container lowering or lifting process, e.g. B. because the driver carelessly sets off too early so that crane movements can be stopped in time.

Based on Fig. 3 A further exemplary embodiment will now be explained, which - like the previous exemplary embodiment - is not only particularly suitable for operational monitoring of work areas of gantry cranes or container bridges, but also for other work areas in the port where containers are or are being deposited.

This can e.g. This could, for example, be a work area on the ship where containers are briefly placed in order to assemble or remove Inter Box Connectors by hand.

In addition, the systems and methods described here can also be used in other areas in container handling areas in ports or elsewhere, even where people do not actually have access, but e.g. B. could accidentally get into fully automated work areas.

Such a generalized procedure is described below using Figures 3 and 4 described.

Fig. 3 shows from above a work surface 3 under a container crane, which is just like in the exemplary embodiment of Fig. 2 is rectangular, with a length and width that matches the size of the container crane used here.

Laser scanner 10 scans the entire work surface 3 of Fig. 3 again and again from above, e.g. B. ten times per second, and in particular detect a container 9, which is hanging here on the crane at a height at which the container 9 could now or at least after further lowering collide with a person standing or walking unfavorably on the work surface 3, as well a person 16 who is here in a corner of the Work surface 3 is standing. In addition, the laser scanners 10 record the directions and speeds of movement of the container 9 and the person 16, which in Fig. 3 are shown as motion vectors using arrows.

Several dynamically changing zones are virtually created on the work surface 3 in order to form multi-level danger areas and/or safety areas. For example, an inner zone 14 is virtually formed horizontally around the container 9, and an outer zone 15 is virtually formed horizontally around the inner zone 14.

As long as the container 9 does not move, the inner zone 14 and the outer zone 15 can be smaller than in Fig. 3 shown, e.g. B. such that the inner zone 14 of the loading position 4 in Fig. 2 corresponds and the outer zone 15 corresponds to the two sub-zones 11, 12 in Fig. 2 corresponds. When the container 9 moves in a horizontal direction, the inner zone 14 and the outer zone 15 are made larger in the direction of movement, the faster the container 9 moves, as in Fig. 3 illustrated.

Such a zone or safety zone that dynamically changes depending on the direction and speed of movement can also be placed around the person 16 (in Fig. 3 not shown), with which the movement of the person 16 can be anticipated. If the recognized person 16 is in a danger area, i.e. the inner zone 14 and/or the outer zone 15, or the safety zone around the person 16 begins to penetrate into the outer zone 15, or conversely, the container 9 approaches the person 16 , the corresponding movements of the trolley, hoist and chassis of the crane are slowed down or stopped.

In particular, the laser scanners 10 scan in the same way as in the exemplary embodiment of Figures 1 and 2 the work surface 3 with a fan of diverging planes of light rays or individual light rays simultaneously in several spaced-apart planes or lines in order to obtain a measuring point cloud, the planes or lines at the height of the work surface 3 being at a distance from one another which is dimensioned in this way is that a person standing on the work surface of at least one plane is hit by light rays or at least one of the individual light rays (step S1 in Fig. 4 ).

In order to be able to recognize a person standing on the work surface with sufficient reliability using relatively few planes or lines, the planes or lines at the height of the work surface 3 should be on the floor in at least one direction, e.g. B. in the longitudinal direction of the loading position and / or transversely to it, not larger than 30 centimeters, although smaller minimum distances such as. B. 10 or 20 centimeters or any intermediate values are possible.

The work surface 3 is also identified in the measurement point cloud obtained in step S1 (step S2 in Fig. 4 ).

It is then determined whether there are at least one or more measurement points in the measurement point cloud that are typical for a person standing on the identified work surface (step S3 in Fig. 4 ). If no such measurement point is determined, it goes back to step S1 to obtain a new measurement point cloud.

If such a measuring point is determined, the crane movement can be slowed down or stopped without any further conditions (step S4 in Fig. 4 ), e.g. B. if the work surface 3 is designed from the outset so that no person should stay there as long as the container 9 is moving, or z. B. in special cases such as test or calibration runs.

However, in step S3 it is preferably additionally determined whether the person 16 or their own security zone is in the outer zone 15 and not in the inner zone 14 or whether it overlaps with it. If so, crane movements are slowed down in step S4. In addition, in step S3 it is determined whether the person 16 or their own security zone is in the inner zone 14 or overlaps with it. If so, crane movements are stopped in step S4. This means that crane movements are only permitted if the person 16 or their own safety zone is not in the inner or outer zone.

Warning signals are preferably also issued when the person 16 approaches the outer zone 15 and before crane movements are slowed down.

Between steps S2 and S3 or S3 and S4 it can also be determined whether there are measurement points in the measurement point cloud that are typical for the truck 5 or its driver's cab 5b and / or loading area 5a and whose locations in the measurement point cloud change over time change. If this is the case, this indicates that the truck 5 is moving, after which crane movements are also stopped.

The method described above, like the first exemplary embodiment, can be expanded to also detect foreign objects in the work area, in particular those that are larger than, for example, B. 30 centimeters to slow down or stop crane movements if necessary, so that the crane operator or person 16 has the opportunity to clarify the situation. Objects that have been accidentally left lying can occur not only on work surfaces 3, but also on truck loading areas 5a, and with the method described, material damage can be avoided when the container is set down. Objects in the work area can be distinguished and classified accordingly not only by their perceived size, but also by the fact that people working there often move around.

For even more reliable recognition of people and objects in the work area, the means and methods described above, which are provided as hardware and software, can be linked to other hardware components and software algorithms for person and object recognition in order to produce a redundant overall system. Using different hardware and software components, the availability and thus also the security of the system are increased.

In addition to the 3D laser scanners 10 described, which form the main components of the security system or collision avoidance system described, cameras can also be used to monitor the presence of people in safe or unsafe areas can be detected. Optionally it would also be possible, e.g. B. to integrate an RFID (Radio Frequency Identification) system, with locations of people in the work area e.g. B. can be recognized using triangulation based on signals that are sent back by an RFID transponder that people are supposed to carry with them, although there can also be people in a container terminal who do not carry an RFID transponder, which is of course important for laser-based person recognition is not necessary.

Each of the different systems works independently and provides the aforementioned information about recognized people. However, the data from the individual systems can be merged in an evaluation software. If at least one system reports a dangerous situation, instructions for suitable countermeasures to avoid the dangerous situation are sent to the crane control system. Ideally, all existing systems report the same information. For availability and safety in dangerous situations, it is sufficient if one of the systems reports a dangerous situation. Such a laser camera, laser RFID or laser camera RFID fusion also facilitates occupational safety certification.

Claims (15)

1. Container-loading system comprising a container crane (10) and a working area (3) accessible to persons on a ground (2) below the container crane (10), wherein at least one elongated loading position (4) for a container road transport vehicle (5) is marked on the working area (3) and wherein at a height above the ground (2) which exceeds a multiple of the height of an ISO container (9) one or more 3D laser scanners (10) are mounted which are adapted to scan the road transport vehicle (5) and the working area (3) from above in three dimensions, wherein the system comprises a person detection unit adapted to cause the laser scanner(s) (10) to perform at least one scan during a container loading operation in order to obtain a cloud of measurement points, characterized in that

   - one or more of the laser scanners (10) is/are of a type adapted to scan the working area (3) with a fan of diverging planes of light beams or a fan of diverging individual light beams simultaneously on a plurality of planes or lines spaced apart from each other in order to obtain the cloud of measurement points, wherein the planes or lines at the level of the working area (3) have a distance from each other which is greater than 10 and less than 30 centimeters in at least one direction on the ground (2);

   - the person detection unit is adapted to identify in the obtained cloud of measurement points the working area (3) and the loading area of the road transport vehicle (5); to determine whether there is at least one measurement point in the cloud of measurement points which is located more than 0.5 meters above the identified working area (3) or the identified loading area and, if there is at least one such measurement point, to issue a person-probable signal; and

   - the system comprises a safety device which is adapted to slow down or stop the crane movement when the person-probable signal is issued.
2. Container-loading system according to claim 1 or 2, characterized in that close to a border or a corner of the working area (3) a person presence zone (13) is marked on the working area (3) and that the safety device is adapted to permit crane movements only when a person-probable signal is emitted for the person presence zone (13) but not for the rest of the working area (3).
3. Container-loading system according to claim 1 or 2, characterized in that the working area (3) is divided into a plurality of zones, namely at least an inner zone (14) comprising at least the loading position (4) and an outer zone (15) extending around and adjoining the inner zone (14); in that the person detection unit is adapted to cause the laser scanner(s) (10) to perform a plurality of successive scans during a container loading operation and, if at least one measuring point lying more than 0.5 meters above the identified working area (3) or the identified loading area is determined, the location of which in the cloud of measurement points varies over time, to issue a moving-person-probable signal; and in that the safety device is adapted to decide whether the crane movement is to be slowed down or stopped depending on which of the two types of signals is issued for which of the two zones (14, 15).
4. Container-loading system according to claim 3, characterized in that the person detection unit is adapted to dynamically vary the location and size of the zones (11, 12) into which the working area (3) is divided during operation of the system and, in particular, to adapt them to the location and direction of movement of a container (9) which is being loaded.
5. Container-loading system according to one of the preceding claims, characterized in that the laser scanners (10) are attached to the container crane (10) or to pillars or poles standing firmly on the ground (2).
6. Method for monitoring operation within a working area (3) on a ground (2) below a container crane (10), wherein from a height above the ground (2) which exceeds a multiple of the height of an ISO container (9), during a container loading, depositing or lifting operation, one or more 3D laser scanners (10) are caused to scan the working area (3) from above in three dimensions in order to obtain a cloud of measurement points,
   characterized by the following method steps:

   - causing the laser scanner(s) (10) to scan the working area (3) with a fan of diverging planes of light beams or a fan of diverging individual light beams simultaneously in a plurality of mutually spaced planes or lines in order to obtain the cloud of measurement points, wherein the planes or lines at the level of the working area (3) are spaced from one another by a distance which is dimensioned such that a person standing on the working area (3) is struck by at least one plane of light beams or at least one of the individual light beams (S1), and which distance is greater than 10 and less than 30 centimeters in at least one direction on the ground (2);

   - identifying (S2) the working area (3) in the obtained cloud of measurement points,

   - determining (S3) whether there is at least one measuring point in the cloud of measurement points which is typical for a person (16) standing on the identified working area (3) and is located more than 0.5 meters above the identified working area (3) or the identified loading surface, and

   - if there is such a measuring point, slowing down or stopping the crane movement (S4).
7. Method according to claim 6, characterized in that crane movements are not slowed down or stopped but permitted if one or more measuring points, which are typical of a person standing in the identified working area (3), are determined for a predefined region at the border of the working area (3), but not for a central region of the working area (3).
8. Method according to claim 6 or 7, characterized in that a plurality of zones are defined within the working area (3), namely at least one inner zone (14) below a container (9) suspended from a crane and an outer zone (15) extending around and adjoining the inner zone (14), wherein

   - crane movements are only permitted if one or more measuring points, which are typical of a person standing in the identified working area (3), are not determined in the inner zone (14) or the outer zone (15);

   - crane movements are slowed down if one or more measuring points, which are typical of a person standing in the identified working area (3), are determined in the outer zone (15) and not in the inner zone (14); and

   - crane movements are stopped when one or more measuring points, which are typical of a person standing in the identified working area (3), are determined in the inner zone (14).
9. Method according to one of claims 6 to 8, characterized in that the location and size of the inner and outer zones (14, 15) are varied in dependence on the location and direction of movement of a container (9) which is being loaded.
10. Method according to one of claims 6 to 9, characterized in that it is additionally determined whether there are at least one or more measurement point(s) in the cloud of measurement points which are typical of a foreign object, wherein a distinction is being made between detected persons and foreign objects on the basis of size and movement.
11. Method according to one of claims 6 to 9, characterized in that it is additionally determined whether there is/are at least one or more measurement points in the cloud of measurement points which is/are typical of a truck (5) and in particular of its driver's cab (5b) and whose locations in the cloud of measurement points vary over time; and in that crane movements are also stopped if it is detected in the aforementioned manner that the truck (5) is moving during a container setting down or lifting operation.
12. Method according to any one of claims 6 to 11, characterized in that it is performed in a container-loading system according to any one of claims 1 to 5.
13. Loading system according to any of claims 1 to 2 or method according to any one of claims 6 to 11, characterized in that the or each of the laser scanner(s) (10) is a 3D multilayer scanner.
14. Loading system according to any of claims 1 to 5 or method according to any one of claims 6 to 11, characterized in that the or each of the laser scanner(s) (10) is a 3D array scanner or a flash LiDAR device.
15. Container-loading system according to one of claims 1 to 5, characterized in that it is adapted to perform the method according to one of claims 6 to 11.

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