Lifting equipment for containers and method for detecting the orientation of containers

Abstract

The present application provides a lifting device for a container and a method for detecting the orientation of the container. The lifting device includes: a spreader, at least two laser range scanners, and a central controller; the spreader has a first end and a second end distributed in a second direction, and when the spreader lifts the container, the second direction is consistent with the first direction of the container; at least one laser range scanner is installed at the first end and the second end respectively, and the laser range scanner is used to emit at least one fan-shaped laser plane towards the container to project laser scanning points and obtain the coordinate values of the laser scanning points in the first direction; the central controller can obtain the orientations and coordinate values of the first end and the second end of the spreader relative to the truck, so as to confirm whether the container door faces the rear of the truck by calculation. If not, an alarm signal is generated. The lifting device can accurately detect the orientation of the container door while having the advantages of simple algorithm, strong anti-interference ability, and simple structure.

Description

Technical Field

[0001] This application relates to the technical field of hoisting equipment, and particularly to a hoisting device for containers and a method for detecting the orientation of containers. Background Art

[0002] At the port terminal, containers are located in the stacking yard. When the containers are transported out of the terminal, a spreader is needed to place the containers on the truck. When placing them on the truck, the container door needs to face the rear of the truck to facilitate subsequent personnel to open the container door and take out the goods inside. If the container door faces in the incorrect direction, the truck needs to go to the fixed crane to turn the direction of the container door.

[0003] In the prior art, there are two methods for detecting the orientation of the container door: (1) manual observation; (2) installing two cameras at both ends of the spreader respectively to collect the image data of the side of the container, and detecting the collected images through image processing or deep learning methods to determine whether the current image contains the container door.

[0004] However, the first method increases the labor intensity of the operator and is not applicable to the fully automatic control process. The second method has high requirements for algorithms and the results are easily affected by external interferences, such as external light and other interferences. Summary of the Invention

[0005] To solve the above technical problems, the embodiments of this application provide a hoisting device for containers and a method for detecting the orientation of containers. The hoisting device can accurately detect the orientation of the container door while having the advantages of simple algorithm, strong anti-interference ability, and simple structure.

[0006] This application provides a hoisting device for containers. The container has a first side plate and a second side plate distributed in a first direction, and a container door is provided on the first side plate. The hoisting device includes a spreader, a central controller, and at least two laser range scanners. The spreader is used to hoist the container onto the truck. The spreader has a first end and a second end distributed in a second direction. When the spreader hoists the container, the first direction is consistent with the second direction. At least one laser range scanner is installed at the first end and the second end respectively. The laser range scanner is used to emit at least one fan-shaped laser plane towards the container to project a plurality of laser scanning points on the first side plate or the container door, project a plurality of laser scanning points on the second side plate, and obtain the coordinate values of each laser scanning point. The central controller is communicatively connected to the laser range scanners to process the coordinate values to determine the position of the container door relative to the first end and the second end of the spreader, and obtain the orientations of the first end and the second end of the spreader relative to the truck to confirm whether the container door faces the rear of the truck. If not, an alarm signal is generated.

[0007] Optionally, the central controller is communicatively connected to the driving unit of the spreader to obtain the orientations of the first end and the second end of the spreader relative to the truck.

[0008] Optionally, the lower surface of the spreader has a plurality of lifting members for connecting with the corner castings on the container. The spreader has a first side surface facing away from the second end and a second side surface facing away from the first end. The laser distance scanner located at the first end is mounted on the first side surface, and the laser distance scanner located at the second end is mounted on the second side surface.

[0009] Optionally, in the first direction, both the first end and the second end of the spreader are flush with the corner castings of the container. The laser emission port of the laser distance scanner located at the first end faces the first side plate or the door of the container and extends out of the lower surface of the spreader. The laser emission port of the laser distance scanner located at the second end faces the second side plate and extends out of the lower surface of the spreader.

[0010] Optionally, at least two of the lifting members are respectively provided at both ends of the spreader in the second direction, and the laser distance scanner at each end is located between two adjacent lifting members.

[0011] Optionally, a plurality of the scanned laser points projected by each fan-shaped laser plane form a string of laser points in the height direction of the container, and the length of the string of laser points is 1 / 3 to 2 / 3 of the height of the container.

[0012] Optionally, the lifting equipment is a rubber-tired gantry crane or a rail-mounted gantry crane.

[0013] Optionally, the lifting equipment includes a projection screen. The central controller is communicatively connected to the projection screen, and the projection screen can display the alarm signal.

[0014] Optionally, the lifting equipment includes a broadcaster. The central controller is communicatively connected to the broadcaster, and the broadcaster can play the alarm signal.

[0015] This application also provides a method for detecting the orientation of a container. This method is applied to the above-mentioned lifting equipment and includes:

[0016] After the orientation of the spreader relative to the truck is determined, controlling the laser distance scanner to emit the fan-shaped laser plane;

[0017] Obtaining the coordinate values of each of the fan-shaped scanning points;

[0018] Calculating the average value of the coordinate values of each of the fan-shaped laser planes;

[0019] Compare the absolute value of the average value with a known distance to determine whether an alarm signal needs to be issued.

[0020] In the case of adopting the above technical solution, since the first side plate of the container is flush with the corresponding corner casting in the first direction, and the corresponding corner casting at the other end extends out of the second side plate, the spreader must extend out of the corner casting or be flush with the corner casting in the first direction. Therefore, when using the spreader to lift the container onto the truck, in the first direction, the distance between the door (or the first side plate) and the first end or the second end of the spreader, and the distance between the second side plate and the second end or the first end of the spreader must be different. Therefore, laser ranging scanners can be installed at both the first end and the second end to detect the distances between the first side plate (or the door) and the second side plate and the corresponding laser ranging scanners respectively; after comparing the two distances, the central controller can determine whether the door is at the first end or the second end of the spreader; during the process of using the lifting equipment to lift the container onto the truck, the central controller can know whether the first end or the second end of the spreader faces the rear of the truck; then, taking the orientations of the first end and the second end of the spreader as a medium, the central controller makes a comparison to determine whether the door is located at the end of the spreader facing the rear of the truck (i.e., the first end or the second end), so as to determine whether the door faces the rear of the truck; if not, it means that the door faces the wrong direction, and the central controller automatically generates an alarm signal. This lifting equipment can accurately detect the orientation of the door while having the advantages of simple algorithm, strong anti-interference ability, and simple structure. Description of the Drawings

[0021] Figure 1 is a schematic top view structure diagram of a container in the prior art.

[0022] Figure 2 is a schematic three-dimensional structure diagram of a lifting equipment for a container when lifting the container provided by an embodiment of the present application.

[0023] Figure 3 is a schematic front view structure diagram of a lifting equipment for a container when lifting the container provided by an embodiment of the present application.

[0024] Figure 4 is a flowchart of a method for detecting the orientation of a container provided by an embodiment of the present application.

[0025] List of Reference Numerals:

[0026] 10, spreader; 20, laser ranging scanner; 30, container; 301, first side plate; 302, second side plate; 31, corner casting.

[0027] S100, after determining the orientation of the spreader relative to the truck, control the laser ranging scanner to emit the fan-shaped laser plane;

[0028] S200. Obtain the coordinate value of each of the fan-shaped scanning points in the first direction;

[0029] S300. Calculate the average value of the coordinate values of each of the fan-shaped laser surfaces;

[0030] S400. Compare the absolute value of the average value with a known distance to determine whether an alarm signal needs to be issued. Detailed implementation manners

[0031] To make the objectives, technical solutions, and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0032] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0033] Before introducing the present application, refer to Figure 1 As shown, first, a brief introduction to the structure of the container 30 will be given. In the prior art, the container 30 has a first side plate 301 and a second side plate 302 distributed in the first direction. A door is provided on the first side plate 301. Corner castings 31 are respectively provided at the four corners above the container 30. At both ends in the first direction, the two corner castings 31 at one end are flush with the second side plate 302, and the two corner castings 31 at the other end both protrude from the first side plate 301. Correspondingly, the spreader has hoisting members corresponding to the four corner castings 31, and the hoisting members are used to connect with the corner castings to achieve the hoisting function.

[0034] Refer to Figure 2 and Figure 3As shown in the figure, the present application provides a lifting device for a container, including a spreader 10, a central controller, and at least two laser distance scanners 20. The spreader 10 is used to lift the container 30 onto a truck. The spreader 10 has a first end and a second end distributed in a second direction. When the spreader 10 lifts the container 30, the first direction is consistent with the second direction. At least one laser distance scanner 20 is respectively installed at the first end and the second end. The laser distance scanner 20 is used to emit at least one fan-shaped laser plane towards the container 30, so as to project a plurality of laser scanning points on the first side plate 301 or the door of the container, project a plurality of laser scanning points on the second side plate 302, and obtain the coordinate values of each laser scanning point. The central controller is communicatively connected to the laser distance scanner 20 to process the coordinate values to determine the position of the door of the container relative to the first end and the second end of the spreader (10). The central controller also obtains the orientations of the first end and the second end of the spreader 10 relative to the truck to confirm whether the door of the container faces the rear of the truck. If not, an alarm signal is generated.

[0035] In the case of adopting the above technical solution, since the first side plate 301 of the container 30 is flush with the corresponding corner casting 31 in the first direction, and the corresponding corner casting 31 at the other end extends out of the second side plate 302, the spreader 10 must extend out of the corner casting 31 or be flush with the corner casting 31 in the first direction. Therefore, when using the spreader 10 to lift the container 30 onto the truck, in the first direction, the distance between the door of the container (or the first side plate 301) and the first end or the second end of the spreader 10, and the distance between the second side plate 302 and the second end or the first end of the spreader 10 must be different. Therefore, laser distance scanners 20 can be installed at both the first end and the second end to detect the distances between the first side plate 301 (or the door of the container) and the second side plate 302 and the corresponding laser distance scanners 20 respectively. After comparing the two distances, the central controller can obtain whether the door of the container is at the first end or the second end of the spreader 10. During the process of using the lifting device to lift the container 30 onto the truck, the central controller can know whether the first end or the second end of the spreader 10 faces the rear of the truck. Then, taking the orientations of the first end and the second end of the spreader 10 as a medium, the central controller makes a comparison to determine whether the door of the container is located at the end of the spreader 10 facing the rear of the truck (i.e., the first end or the second end), so as to determine whether the door of the container faces the rear of the truck. If not, it means that the orientation of the door of the container is incorrect, and the central controller automatically generates an alarm signal to remind the relevant personnel that they need to adjust the orientation of the container 30. For example, drive the truck to a fixed lifting point and use the fixed lifting device to turn the door of the container towards the lifting point.

[0036] A method for obtaining the distances between the first side plate 301 (or the door) and the second side plate 302 and the corresponding laser distance scanners 20 respectively can be as follows: Establish a coordinate system with the position where the laser distance scanner 20 is located as the origin O. For example, the first direction is the same as the X direction of the coordinate system, and the height direction of the container 30 is the same as the Y direction of the coordinate system. Then the distances between the first side plate 301 (or the door) and the second side plate 302 and the laser distance scanner 20 respectively are the absolute values of the corresponding X coordinates. The laser distance scanner 20 can obtain the X coordinates of all the laser scanning points formed by each fan-shaped laser surface. After the central controller obtains these X coordinates, it can perform an averaging operation on all these X coordinates of each fan-shaped laser surface to obtain the average X coordinate. The absolute value of the average X coordinate is the required distance. It should be noted here that since the door is arranged on the first side plate 301, it can be roughly considered that their outer surfaces are flush. Then, if the origin O is located on the side surface of the spreader, no matter whether the laser scanning point is on the door or on the first side plate 301, the measured distance is approximately L (refer to Figure 1 ).

[0037] Since the laser distance scanner 20 is already installed on the spreader 10, after the spreader 10 hoists the container 30, their relative positions in the first direction are fixed. Therefore, the distances between the first side plate 301 (or the door) and the second side plate 302 and the corresponding laser distance scanners 20 respectively are also known, and the two are different. Then the central controller can compare the required distance with the known distance to determine which laser distance scanner 20 corresponds to the door, that is, to determine whether it is the first end or the second end of the spreader 10 that corresponds to the door. Here, the method of taking the average of multiple laser scanning points can ensure the accuracy of detection and reduce the risk of false alarms.

[0038] For example, as Figure 2 and Figure 3 shown, for the convenience of description, it is assumed that the origin O is located on the side surface of the spreader 10 as an example for introduction. Assume that the first end corresponds to the first side plate 301 (or the door), and the second end corresponds to the second side plate 302. Then the laser scanning points formed on the door are distributed in the CD section, and the absolute value of the corresponding average X coordinate is the distance between the origin O of the laser scanner at the first end and the door. This distance should be equal to the length L by which the angle casting 31 extends from the first side plate 301. Then the laser scanning points formed on the door are distributed in the EF section, and the absolute value of the corresponding average X coordinate is the distance between the origin O of the laser scanner at the second end and the second side plate 302. This distance should be equal to zero. Thus, it can be determined which end corresponds to the door.

[0039] Obviously, for the hoisting device provided by the present application, on the one hand, the laser distance scanner 20 is used for detecting the container door, and the algorithm is simple and the accuracy is high. That is, only the detected distance value needs to be converted into the coordinate value in the first direction, and then a simple average operation is performed on the coordinate values to obtain the result by comparison. On the other hand, the laser distance scanner 20 is installed on the side of the spreader 10 and is only used when hoisting the container 30, which can ensure that there are few obstacles between the laser distance scanner 20 and the container 30, so it has the advantages of less interference and strong anti-interference ability. Thirdly, only the laser distance scanner 20 needs to be installed at both ends of the spreader 10, with a simple structure, easy to implement and low cost.

[0040] In summary, the hoisting device provided by the present application can accurately detect the orientation of the container door while having the advantages of simple algorithm, strong anti-interference ability and simple structure.

[0041] In one example, the laser distance scanner 20 includes a processor, which is used to process the scanning mechanism, determine the coordinate value of each scanning point, and then send the coordinate value to the central controller.

[0042] One method for the laser distance scanner 20 to obtain the coordinate value can be: taking the position where the laser distance scanner 20 is located as the origin, the first direction as the X-axis, and the height direction of the container 30 as the Y-axis to form a coordinate system; the scanning result of the laser distance scanner 20 includes the straight-line distance between the laser distance scanner 20 and the scanning point, and the included angle formed by the laser distance scanner 20 and the scanning point. Based on these two parameters and the cosine function, the processor can calculate the coordinate value of the scanning point in the first direction.

[0043] There are various ways for the laser distance scanner 20 to emit a fan-shaped laser plane. In one example, the laser distance scanner 20 may include a laser emitter and a rotating motor, and the rotating motor is used to drive the laser emitter to rotate and emit a fan-shaped laser plane. The rotating motor runs at a high speed, and the laser line emitted by the laser emitter rotates quickly, emitting the laser lines in all directions required for the fan-shaped laser plane in a very short time to form a laser plane. Among them, the interval between adjacent laser lines can be adjusted by adjusting the speed of the rotating motor. The interval can be selected according to needs and is not limited here.

[0044] In a possible implementation, the central controller is connected to the control unit of the spreader 10 in communication to obtain the orientation of the first end and the second end of the spreader 10 relative to the truck. When this technical solution is adopted, according to the terminal regulations, the orientation of the truck used to transport the container 30 is pre-set, that is, the central controller can know the orientation of the truck in advance. Under this premise, the control unit can control the orientation of the first end and the second end of the spreader 10 relative to the truck, and feed back the orientation information to the central controller, so that the central controller obtains the orientation of the first end and the second end of the spreader 10 relative to the truck.

[0045] In one example, instructions can be sent to the control unit through the central controller, and the control unit controls the orientation of the first end and the second end of the sling 10 relative to the truck according to the instructions, so that the orientation information can be automatically stored in the central controller; in another example, instructions can be sent to the control unit by other devices (such as a manual operating console), and the central controller obtains the orientation information from the control unit.

[0046] In a possible embodiment, the central controller can send an alarm signal to the control unit to prompt the control unit that the direction is wrong. After the lifting is completed, no more lifting is performed to reserve time for the relevant staff to drive the truck away to change the direction of the box door. After the new truck enters the waiting position, the central controller receives the new command and sends a new instruction to the control unit, and the control unit controls the spreader 10 to perform the lifting operation again.

[0047] In another possible implementation, the orientation information of the spreader 10 relative to the truck may be manually input to the central controller.

[0048] In a possible implementation, the lower surface of the sling 10 has a plurality of lifting components, which are used to connect with the corner casting 31 on the container. The sling 10 has a first side surface facing away from the second end, and a second side surface facing away from the first end. The laser rangefinder 20 located at the first end is installed on the first side surface, and the laser rangefinder 20 located at the second end is installed on the second side surface. The "upper and lower" here are defined based on the direction of gravity during lifting, that is, the sling 10 is located above the container 30. When this technical solution is adopted, the possibility of the laser rangefinder 20 being damaged by collision can be reduced when the lifting components are connected to the corner casting 31.

[0049] In a possible implementation, in the first direction, both the first end and the second end of the spreader 10 are flush with the corner fitting 31 of the container 30; the laser emission port of the laser distance scanner 20 at the first end faces the first side plate 301 or the container door, and extends out of the lower surface of the spreader 10, and the laser emission port of the laser distance scanner 20 at the second end faces the second side plate 302 and extends out of the lower surface of the spreader 10. In the case of adopting this technical solution, making the laser emission port face the container 30 and extend out of the lower surface of the spreader 10 can ensure that the fan-shaped laser surface emitted is not blocked by the spreader 10 and can all be projected onto the container 30, obtaining more laser scanning points and improving the detection accuracy.

[0050] In a possible embodiment, at least two lifting members are respectively arranged at both ends of the spreader 10 in the second direction, and the laser distance scanner 20 at each end is located between two adjacent lifting members. In the case of adopting this technical solution, since the laser distance scanner 20 is installed on the side surface of the spreader 10 and the lifting members are located on the lower side of the spreader 10, therefore, making the laser distance scanner 20 located between two adjacent lifting members can avoid the problem that the fan-shaped laser surface is blocked by the lifting members or the corner fitting 31 on the container 30, resulting in inaccurate measurement results.

[0051] In a possible implementation, a plurality of scanned laser points projected by each fan-shaped laser surface form a laser point string in the height direction of the container 30, and the length of the laser point string can be 1 / 3 to 2 / 3 of the height of the container 30. In this way, the longer scanning length can increase the measurement accuracy.

[0052] In an example, the angle of the fan-shaped laser surface can be 60° - 110°. This angle range can project more laser scanning points on the container 30 to increase the measurement accuracy.

[0053] In a possible implementation, the lifting device provided in the present application can be a rubber-tired gantry crane or a rail-mounted gantry crane. Of course, the lifting device can also be other forms of cranes, which are not limited in the present disclosure.

[0054] In a possible implementation, the lifting device provided in the present application includes a projection screen, the central controller is communicatively connected to the projection screen, and the projection screen can display an alarm signal. In the case of adopting this technical solution, the truck driver or relevant staff only needs to observe the projection screen to know whether the container door is facing the wrong direction.

[0055] In a possible implementation, the lifting device provided in the present application includes a broadcaster, the central controller is communicatively connected to the broadcaster, and the broadcaster can play an alarm signal. In the case of adopting this technical solution, the form of voice broadcast can remind the truck driver or relevant staff to timely obtain the alarm signal.

[0056] The alarm signal may include the code of the truck so that the truck driver or relevant staff can clearly know which truck has the wrong door direction of the container 30. The code may be a manually sorted code or a truck license plate number, which is not limited in this application.

[0057] The present application also provides a method for detecting the orientation of a container, using the above-mentioned lifting equipment, the method comprising the following steps:

[0058] S100: After the orientation of the spreader 10 relative to the truck is determined, the laser rangefinder scanner 20 is controlled to emit a fan-shaped laser surface. Here, the orientation of the spreader 10 relative to the truck is determined by the central controller determining whether the first end or the second end of the spreader 10 is facing the rear of the vehicle, that is, the central controller obtains the orientation information. The specific acquisition method can refer to the above description and will not be repeated here. Then, by emitting a fan-shaped laser surface and calculating and comparing the following steps, it can be determined whether the orientation of the box door is facing the rear of the truck. If so, the orientation is correct; if not, the orientation is incorrect and an alarm signal needs to be issued.

[0059] S200: Obtain the coordinate value of each sector scanning point in the first direction. That is, the central controller is in communication connection with the laser distance measuring scanner 20, and after the laser distance measuring scanner 20 obtains the coordinate value, it can send the coordinate value to the central controller.

[0060] S300: Calculate the average value of the coordinate values ​​of each fan-shaped laser surface.

[0061] S400: Compare the absolute value of the average value with the known distance to determine whether an alarm signal needs to be issued. The known distance here is the distance between the origin O of the coordinate system at the first end and the first side plate 301 or the second side plate 302 of the container 30 in the first direction, and the distance between the origin O of the coordinate system at the second end and the second side plate 302 or the first side plate 301 of the container 30 in the second direction. This distance can be designed as needed when installing the laser ranging scanner 20, and is not limited here. For example, the origin O can be located on the side of the sling 10. After comparison, the central controller determines which laser ranging scanner 20 corresponds to the box door, that is, determines whether the box door corresponds to the first end or the second end of the sling 10. Then, based on the determined orientation of the first and second ends of the sling 10 relative to the truck, it can be determined whether the box door is facing the rear of the truck.

[0062] Through the above method, it is possible to detect whether the orientation of the cabinet door is correct.

[0063] To implement the above method, corresponding programs should be stored in the controller so as to be able to control the laser ranging scanner 20 to emit a fan-shaped laser plane, process coordinate values, and be able to emit an alarm signal.

[0064] In addition, for the specific implementation of each step in the program, reference can be made to the corresponding steps and the descriptions in the corresponding units in the foregoing method embodiments, which will not be elaborated herein. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the devices and modules described above can refer to the corresponding process descriptions in the foregoing method embodiments, which will not be elaborated herein again.

[0065] It should be noted that according to the needs of implementation, each component / step described in the embodiments of the present invention can be split into more components / steps, or two or more components / steps or partial operations of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of the present invention.

[0066] The method according to the embodiments of the present invention described above can be implemented in hardware, firmware, or be implemented as software or computer code that can be stored in a recording medium (such as a CD ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or be implemented as computer code that is originally stored in a remote recording medium or a non-transitory machine-readable medium and downloaded through a network and will be stored in a local recording medium, so that the method described herein can be stored in such software processing on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as an ASIC or FPGA). It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component (such as a RAM, a ROM, a flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the method shown herein, the execution of the code converts the general-purpose computer into a dedicated computer for executing the method shown herein.

[0067] Those of ordinary skill in the art can realize that the units and method steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the embodiments of the present invention.

[0068] The above embodiments are only used to illustrate the embodiments of the present invention, rather than to limit the embodiments of the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present invention. The patent protection scope of the embodiments of the present invention shall be defined by the claims.

Claims

1. A lifting device for a container, the container (30) having a first side plate (301) and a second side plate (302) distributed in a first direction, and a door being provided on the first side plate (301). Characterized in that corner castings (31) are respectively provided at the four corners above the container (30), and at both ends in the first direction, the two corner castings (31) at one end are flush with the second side plate (302), and the two corner castings (31) at the other end both protrude from the first side plate (301); the lifting device further includes: a spreader (10) for lifting the container (30) onto a truck, the spreader having lifting members corresponding to the four corner castings (31), and the lifting members being used to connect with the corner castings to achieve the lifting function; the spreader (10) has a first end and a second end distributed in a second direction, and when the spreader (10) lifts the container (30), the first direction is consistent with the second direction; at least two laser range scanners (20), with at least one of the laser range scanners (20) being installed at the first end and the second end respectively, the laser range scanners (20) being used to emit at least one fan-shaped laser plane towards the container (30) to project a plurality of laser scanning points on the first side plate (301) or the door, project a plurality of laser scanning points on the second side plate (302), and obtain the coordinate values of each of the laser scanning points; a central controller, communicatively connected to the laser range scanners (20) to process the coordinate values to determine the position of the door relative to the first end and the second end of the spreader (10), and obtain the orientations of the first end and the second end of the spreader (10) relative to the truck to confirm whether the door faces the rear of the truck, and if not, generate an alarm signal; wherein, laser range scanners (20) are installed at both the first end and the second end to detect the distances between the first side plate (301) or the door and the second side plate (302) and the corresponding laser range scanners (20) respectively; after comparing the two distances, the central controller can obtain whether the door is at the first end or the second end of the spreader (10); the central controller makes a comparison with the orientations of the first end and the second end of the spreader (10) as a medium to judge whether the door is located at the end of the spreader (10) facing the rear of the truck.

2. The lifting device for a container according to claim 1, Characterized in that the central controller is communicatively connected to the control unit of the spreader (10) to obtain the orientations of the first end and the second end of the spreader (10) relative to the truck.

3. The lifting device for a container according to claim 1, Characterized in that The lower surface of the spreader (10) has a plurality of lifting members for connecting with the corner castings (31) on the container. The spreader (10) has a first side surface facing away from the second end and a second side surface facing away from the first end. The laser distance scanners (20) located at the first end are installed on the first side surface, and the laser distance scanners (20) located at the second end are installed on the second side surface.

4. The lifting device for a container according to claim 3, wherein, in the first direction, both the first end and the second end of the spreader (10) are flush with the corner casting (31); the laser emission port of the laser distance scanner (20) located at the first end faces the first side plate (301) or the container door and extends out of the lower surface of the spreader (10), and the laser emission port of the laser distance scanner (20) located at the second end faces the second side plate (302) and extends out of the lower surface of the spreader (10).

5. The lifting device for a container according to claim 4, wherein, at least two of the lifting members are respectively arranged at both ends of the spreader (10) in the second direction, and the laser distance scanners (20) at each end are located between two adjacent lifting members.

6. The lifting device for a container according to claim 1, wherein, a plurality of laser scanning points projected by each fan-shaped laser surface form a string of laser points in the height direction of the container (30), and the length of the string of laser points is 1 / 3 to 2 / 3 of the height of the container (30).

7. The lifting device for a container according to claim 1, wherein, the lifting device is a rubber-tired gantry crane or a rail-mounted gantry crane.

8. The lifting device for a container according to any one of claims 1-7, wherein, the lifting device includes a projection screen, the central controller is communicatively connected with the projection screen, and the projection screen can display the alarm signal.

9. The lifting device for a container according to any one of claims 1-7, wherein, the lifting device includes a broadcaster, the central controller is communicatively connected with the broadcaster, and the broadcaster can play the alarm signal.

10. A method for detecting the orientation of a container, wherein, using the lifting device according to any one of claims 1-8 above, the method includes: after the orientation of the spreader (10) relative to the truck is determined, controlling the laser distance scanner (20) to emit the fan-shaped laser surface (S100); acquiring the coordinate values of each laser scanning point (S200); calculating the average value of the coordinate values of each fan-shaped laser surface (S300); comparing the absolute value of the average value with a known distance to determine whether to issue an alarm signal (S400).

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