Container door detection system and method

Abstract

A system for detecting a position of a container door including: a 3D sensor arranged to detect and generate 3D spatial data map; said 3D spatial data map including an array of data points, said data points defined by their respective x,y,z coordinate, wherein x,y coordinate is a plane vertical to the 3D sensor axis and z coordinate a distance function from the 3D sensor perpendicular to the xy plane; a processor arranged to receive positional data from the sensor, said processor including an algorithm arranged to analyse the position data to determine the door closure status.

Description

[0001] CONTAINER DOOR DETECTION SYSTEM AND METHOD

[0002] Field of Invention

[0003] The invention relates to modal transport systems, including shipping containers. In particular, the invention is related to safety systems for such containers, including ensuring any closures of the container are secured.

[0004] Background

[0005] Shipping containers are moved around from location to location, within and beyond the port, utilising a variety of equipment.

[0006] For those container movements that involve vertical lifting, the containers are typically lifted with a container spreader fitted to lifting equipment such as quayside crane, stacking crane, which are relatively fixed installation operating within a limited zone and pre-defined paths and mobile equipment such as straddle carrier, reach stacker etc., which shuttle containers between the quay and the yard.

[0007] For the container movement which is purely horizontal in nature, containers are placed directly on a bed of a mobile equipment and wheeled around without a spreader. These trucks include both driver and driverless vehicle such as AGV (Automatic Guided Vehicle), autonomous truck, conventional tow truck etc.

[0008] A container door must be closed at all times during transportation to minimise collision risk. An open door that swings open during transportation could collide with surrounding equipment and / or personnel, resulting in property damage and / or a fatality.

[0009] Conventionally, mitigation of this collision risk is, to a certain extent, dependent on human attention as most of the container transportation equipment are manned.In recent years, as unmanned transportation equipment in the port has become increasingly routine, it is timely and crucial to have a door detection system on these transportation devices to detect and allow intervention when the door is not in a closed position.

[0010] Summary of Invention

[0011] In a first aspect, the invention provides a system for detecting a position of a container door including: a 3D sensor arranged to detect and generate 3D spatial data map; said 3D spatial data map including an array of data points, said data points defined by their respective x,y,z coordinate, wherein x,y coordinate is a plane vertical to the 3D sensor axis and z coordinate a distance function from the 3D sensor perpendicular to the xy plane; a processor arranged to receive positional data from the sensor, said processor including an algorithm arranged to analyse the position data to determine the door closure status.

[0012] In a second aspect, the invention provides a method for detecting a position of a container door including the steps of: mounting a 3D sensor on a container carrying device; determining whether a container has been received by the container carrying device; capturing and transmitting a positional data map of the container door to a processor; analysing and determining from the positional data map the position of the container door.

[0013] An objective of the present invention is to have a mountable container door status detection system (CDDS). Said CDDS being mountable to a container carrying device.In one embodiment, the CDDS may be part of a spreader control system to detect container door status (i.e. Open / Close) and alert the transportation equipment to take necessary action, including a slowdown or halt of all transportation movement, or issue an alert for human intervention.

[0014] In a further embodiment, the CDDS may be mounted to a mobile horizontal transportation device, without a spreader In this embodiment, the principle and methodology of the CDDS may be similar to that of the spreader mounted CDDS. However, in the absence of a spreader, the CDDS may be mounted at a suitable location on the transportation device itself, for example on a container bed of a container trailer or automated guided vehicle (AGV) and the electrical and control system will be either an independent system or part of transportation equipment control system.

[0015] Brief Description of Drawings

[0016] It will be convenient to further describe the present invention with respect to the accompanying drawings which illustrate possible arrangements of the invention. Other arrangements of the invention are possible, and consequently the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention.

[0017] Figure 1 is an elevation view of a container terminal, providing a flow path from a vessel to transportation;

[0018] Figures 2A and 2B are various views of a first category of shipping container;

[0019] Figures 3A to 3E are isometric views of several categories of shipping containers;Figure 4 is a schematic view of a mountable CDDS according to a first embodiment of the present invention;

[0020] Figures 5A and 5B are isometric views of mounting positions for a spreader mounted CDDS, according to one embodiment of the present invention;

[0021] Figure 6A is an elevation view of a container having a CDDS mounted thereto, according to one embodiment of the present invention;

[0022] Figure 6B is a 3D spatial image scan from a CDDS of Figure 6A;

[0023] Figure 7A is a plan view of a container door in the closed position;

[0024] Figure 7B is a 3D spatial image scan from a CDDS of Figure 7A, according to one embodiment of the present invention;

[0025] Figure 8A is a plan view of a container door in the partially open position;

[0026] Figure 8B is a 3D spatial image scan from a CDDS of Figure 8 A, according to one embodiment of the present invention;

[0027] Figure 9 is a 3D spatial image scan from a CDDS of a container door in a substantially open position, according to one embodiment of the present invention;

[0028] Figure 10A is a plan view of a container door in the fully open position;

[0029] Figure 10B is a 3D spatial image scan from a CDDS of Figure 10A, according to one embodiment of the present invention, and;

[0030] Figure 11 is a flow chart providing a process performed by the CDDS according to a further embodiment of the present invention.Detailed Description

[0031] Figure 1 shows the path of a container taken from a vessel 35 to landside transport 25, 30. The container terminal 5 of Figure 1. A quayside crane 40 on the waterside area 10 lifts the container from a vessel 35 and places it within a waterside transfer area 15, for an awaiting internal vehicle 45. The vehicle may be operated by a human, be semi-autonomous or fully autonomous, depending upon the arrangement in the terminal 5.

[0032] The internal vehicle 45 then delivers the container to the storage yard 20, where stacking cranes 50 place and catalogue the position of the container, for future transportation. At the appropriate time, the container may be transported to the landside transfer area 25 for loading 27 to an external vehicle 55, or further delivered 23 to an internal vehicle 60, for loading to a train 65.

[0033] Figures 2A, 2B and 3 A to 3E show various types of containers, having various types of closures. In one arrangement of Figures 2A and 2B, a container 70 according to the ISO 668 standard, which includes a single door 75, located at one end of the container. The door includes various hardware including door panels 110A / B, door locking handle 135, locking bars 145, J-bars 105, and other appropriate door hardware 80, 85, 90, 95, 100, 115, 130, 140, 155, 160.

[0034] Figure 3A shows an alternative container 165, where one longitudinal side of the container 165 comprises a double panel door. Figure 3B shows a container 170 having an end door and a longitudinal side door. Figure 3C shows an open top container 175, having a soft removable cover, and a door similar to that of Figure 2A. Figure 3D shows a container 180 having a side end door, of a size similar to that of a building Figure 3E shows a container 185 similar to Figure 3C, with an end door that swings downward to form a ramp.The CDDS according to the present invention includes a capability to monitor and act upon closures including those of Figures 3 A to 3E.

[0035] Figure 4 shows a schematic view of a CDDS 190 according to one embodiment. The body of the CDDS unit 190 includes a pair of CDS cameras 195, 200 spaced so as to provide sufficient 3D positional data. Within the body is a PC 210 having a processor to operate the CDDS, receive 205 3D positional data from the cameras and analyse the position data with an algorithm to determine the door closure status. The control system may further include operable functions capable of acting upon the positional data received from the cameras through receiving input or transmitting an output 215 through an input / output unit 205.

[0036] The placement of the CDDS unit will be such that the cameras / 3D sensors, have a clear line of sight, and able to obtain a sufficient depth of view to identify the arrangement of the door. For containers 70 having an opening 75 comprising door panels 110A, l 10B, the container carrying device may have a 3D sensor placed to capture positional data for each door panel 110A, l 10B. In cases where there are two adjacent door panels 110A,l 10B, such as shown in Figure 6A, a single 3D sensor may be sufficient to capture positional data from both door panels 110A,110B, if placed above the door panels seal 85.

[0037] Figures 5A and 5B show two such arrangements. Figure 5A shows a 3D sensor / camera 240, in communication with the CDDS unit 240, placed on a spreader 215, directly above the door of a container similar to that of Figure 2A. It may be placed near to the end beam centre and at an appropriate height and angle to provide a clear view of a region covering around the container edge and the centreline where the left and right door panel meet. The 3D sensors capture measurements in 3D spatial dimension and feedback to a data process units which analyse the data to determine door status, ie whether it is in open or close position, and generate an outputto spreader controller. The use of 3D sensor greatly simplifies data processing and analysis and improves detection reliability.

[0038] Figure 6B shows the 3D sensor capture measurement as a 3D Point Cloud, with each measurement consisting of an array of data points in (X,Y,Z) spatial locations. As an example, of a 3D Point Cloud, IFM Model 03D300 3D sensor capture measurement, from a 40 x 30 degrees field-of-view with 5 measurements taken per second and each measurement has 176 x 132 data points in (X,Y,Z) spatial locations For ease of human interpretation, 3D sensor data may be displayed as a “range image” where the pixel location represents the (X,Y) coordinate system of the captured image and the pixel characteristics being a function of the (Z) distance from the sensor to the object. In this image, the pixel characteristics are colour 255, 260, 265, but they may also be pixel size, pixel shape or other differentiating aspect. The image colours are not related to the appearance of the object as in a camera’s “colour image”. The colour ranges from blue / green / yellow / red 255, 260, 265 to illustrate the (Z) distance between sensor and object from near to far.

[0039] In one embodiment, the CDDS system may not require a large database of containers information (such as container images) as the reference information, which would otherwise be used to compare and define door status. In this embodiment, the system according to present invention may detect a container door status using a generic algorithm, without need for reference information The system may detect and define a status of a container door, i.e. whether it is at open or close position, by analysing the capture measurements.

[0040] Figure 7B shows a range image of a container with its door 275 at close position (Figure 7A). The system identifies that the door is at closed position based on:1. The presence of door panel - as shown in green lines 283 (locking bar) within the blue 285 (container)

[0041] 2. The door is not protruding out of container envelope - as could be seen from the demarcating line 280 between the ground 281 (red) and the container 285 (blue), which remain straight and at the predetermined location and orientation(centre and horizontal)

[0042] Figure 8B shows a range image of a container with its door 295 at a slightly open (40 mm) position (Figure 8A). The system identifies that the door is at slightly open position based on:

[0043] 1. The presence of right door panel - as shown in green lines 300 (locking bar) within the blue 305 (container door)

[0044] 2. The presence of left door panel - as could be seen from the blue patch 313 (door) in between the red 317 (ground) and multi-colour 310 (green / yellow / orange), the inner space 315 of container which by now visible.

[0045] 3. The left door has protrude out of container envelope - as could be seen from the demarcating line between the ground(red) and the container(door ), which is no longer straight, and shifted from it predetermine location and orientation, i.e. no longer horizontal and near the centre.

[0046] Figure 9 shows a range image of a container with its door at a substantially open position. The system identifies that the door is at substantially open position based on:

[0047] The presence of right door panel - as shown in green lines 325 (locking bar) within the blue 320 (container door)

[0048] 1. The presence of left door panel and protrusion out of container envelope - as could be seen from the blue-orange-green patch 335 (door) has shifted away from Blue 320 (container)and is entirely in red region 345 (ground). Also the multi-colour 330 (green / yellow / orange) range within the container inner space also visible.

[0049] Figure 10B shows a range image of a container with its door at wide open position 350 (Figure 10A). In this case, the left door is wide open and go beyond the viewing field of the 3D sensor. The system identifies the absent of the door and assume it is wide open. :

[0050] 1. The presence of right door panel - as shown in green lines 385 (locking bar) within the blue 365 (container door)

[0051] 2. The absent of left door panel - Absent of green-blue-yellow 360 (Door) in the Red 355 (ground) and present of multi-colour 380 (green / yellow / orange), i.e the inner space of container which by now visible.

[0052] The novel characteristics of the CDDS, according to the present invention, may include:

[0053] 1. Spreader mounted CDDS system

[0054] 2. Based on 3D spatial measure taken by 3D camera / Sensor

[0055] 3. A detection algorithm without a requirement for a reference container image database 4. The algorithm analyses captured 3D spatial measurement to detect various containers components and their relative position to each other, such as between container body and door etc. to determine if the door is in open or close position.

[0056] In contrast to the prior art, based on conventional 2D image technology, it does not depend on any specific container design and or any specific physical features of the container to identify container component and it position.

[0057] In a further embodiment, the CDDS may operate as a standalone system arranged to issue an alarm when detecting an open door. In a further embodiment, the system according to thepresent invention may be integrated with container handling equipment and issue an alarm and / or feedback to container handling equipment for necessary action or / and interventions

Claims

Claims1. A system for detecting a position of a container door including:a 3D sensor arranged to detect and generate 3D spatial data map;said 3D spatial data map including an array of data points, said data points defined by their respective x,y,z coordinate, wherein x,y coordinate is a plane vertical to the 3D sensor axis and z coordinate a distance function from the 3D sensor perpendicular to the xy plane;a processor arranged to receive positional data from the sensor, said processor including an algorithm arranged to analyse the position data to determine the door closure status.

2. The system according to claim 1, wherein the 3D sensor is mountable to any one of: a spreader, a container trailer, container truck or autonomous guided vehicle.

3. The system according to claims 1 or 2, wherein the positional data includes locations of container door hardware.

4. The system according to claim 3, wherein the processor is arranged to identify the position of the door based upon the positional data, such that the position of the container door hardware relative to the container indicates the position of the door.

5. A method for detecting a position of a container door including the steps of:mounting a 3D sensor on a container carrying device;determining whether a container has been received by the container carrying device; capturing and transmitting a positional data map of the container door to a processor; analysing and determining from the positional data map the position of the container door.

6. The method according to claim 5, including the step of activating an alarm if the position of the container door is in any position other than closed position

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