Field of the Invention
[0001] The present invention generally relates to moving a container from a terminal truck
using a gantry crane, for example loading a container or several containers from a
terminal truck onto a ship using a ship-to-shore crane that is located on the quay
along a dock in a harbour. The gantry crane has a spreader to pick-up the container
from the terminal truck's trailer and drop the container on the ship, and the gantry
crane typically is positioned on rails such that it can move substantially parallel
to the quay border.
Background of the Invention
[0002] In order to optimize the ship loading process, alignment of the terminal truck carrying
a container to be loaded onto the ship relative to the crane is important to avoid
that any crane displacement is needed in order to move a container from the trailer
or chassis of the terminal truck onto the ship. More precisely, alignment of the container
residing on the trailer of the terminal truck relative to the crane's spreader must
be accomplished with a typical alignment accuracy of 10 centimetres or less. Otherwise,
displacement of the gantry crane along the rail is needed before the spreader can
pick-up the container from the trailer. Such crane displacements along the rail in
order to align the spreader of the crane with the containers to be picked-up are time
consuming and consequently significantly reduce the container terminal efficiency
expressed as an amount of containers that is loaded onto the ship per time unit.
[0003] It is common practice to assist the driver of a terminal truck with driving instructions
that enable to position the terminal truck at a desired location. International patent
application
WO 2018/087141 A1 entitled "Radio-Location System for Determining the Location of a Transportation
Vehicle for Containers" describes a positioning system for a transportation vehicle
for containers in a working area. The system known from
WO 2018/087141 A1 consists of plural antennas roof-mounted on the truck and location markers, i.e.
other antennas, spread across the working area. Through radio technology, accurate
determination of the position of the truck is possible. The position information is
used to generate driving instructions for the truck driver.
[0004] Although the truck is accurately located through the radio technology, the system
of
WO 2018/087141 A1 fails to accurately determine the position of the container to be moved from the
truck trailer onto the ship. Nevertheless, rather the position of the container is
important instead of the position of the truck cabin. The position of the container
can vary for various reasons: the chassis or trailer of a terminal truck typically
has no pins as a result of which the container has no predetermined, fixed position
relative to the terminal truck cabin, the size of the container can vary (for example
20 ft, 40 ft, 45 ft, ...), multiple containers may reside on a single trailer (for
example the same trailer may be used to carry two 20 ft containers or a single 40
ft container), etc.
[0005] Alternative existing systems that determine the position of a truck relative to a
crane relying on laser scanners. The LASETPC system described at URL:
https://www.lase.de/en/products/port-logistics/truck-positioning-sts.html relies on
3D laser scanners positioned on the crane to determine the position of the truck,
trailer or container with alleged millimetre accuracy.
[0006] Also US patent application
US 2013/0147640 A1 entitled "Container Handler Alignment System and Method" describes a system with
laser scanners in fixed positions on the crane's sill beam to determine the type,
position and orientation of a vehicle, and a processor that generates driving instructions
for the vehicle driver. The system known from
US 2013/0147640 A1 allegedly outperforms other laser-based systems in that a reduced number of lasers
is used therein, i.e. a first laser to detect presence, location and orientation of
any vehicle and a second laser to determine presence, location and orientation of
containers loaded on the vehicle. Direction indicators attached to the sill beams
indicate to the vehicle drivers whether their vehicle is properly positioned, needs
to be moved backward or forward, and whether their vehicle orientation is skewed.
[0007] Laser based systems like LASETPC or the one known from
US 2013/0147640 A1 are disadvantageous for several reasons. Firstly, laser technology is expensive,
contains moving components like mirrors, and is therefore complex in maintenance.
Laser scanners are mechanical devices that can get broken. This is even worse in a
demanding environment like a harbour where wet, windy and salty conditions are common.
This problem is recognized in
US 2013/0147640 A1 which therefore aims at reducing the amount of lasers in a vehicle alignment system.
Laser technology is further disadvantageous because its functioning and accuracy are
weather dependent. In rainy and/or foggy weather conditions, laser technology loses
accuracy or even fails. Wet contours of a container for instance are difficult to
detect through laser scanners as a result of which existing laser-based vehicle alignment
systems fail to provide accurate driving instructions to terminal truck drivers in
rainy weather. When more lanes are used in a terminal to transfer containers from
terminal trucks to a ship, the cost for deploying and maintaining laser technology
to align terminal trucks with the gantry crane is even worse, as more laser devices
are required to scan the different lanes and more direction messaging boards are required
to guide the terminal truck drivers in the different lanes.
Summary of the Invention
[0008] It is an object to disclose embodiments of a system and method enabling alignment
of a terminal truck relative to a gantry crane that resolve one or more of the above
identified shortcomings of existing systems. More particularly it is an object to
provide a system and method that improves the efficiency of the container loading
process through accurate alignment of the container(s) carried by a terminal truck
relative to the gantry crane. It is a further object to provide such a system and
method that is less sensitive to weather conditions, that operates reliably under
a crane, that is less expensive in and less demanding in maintenance.
[0009] According to the present invention, one or more of the above identified objectives
are achieved through a system enabling alignment of a terminal truck relative to a
gantry crane as defined by claim 1, the terminal truck comprising a tractor and a
trailer holding at least one container to be picked up by the crane, the system comprising:
- a position determination unit configured to determine a tractor position for the tractor
relative to the crane;
- a receiver with connectivity to an external system, the receiver being configured
to receive from the external system container information indicative for the size
of the at least one container;
- a distance measurement unit configured to measure a distance between a reference point,
line or plane at the tractor and a front surface of the at least one container based
on reflective technology; and
- a computing unit coupled to the position determination unit, the receiver and the
distance measurement unit, the computing unit being configured to collect the tractor
position, the container information, and the distance, and further being configured
to generate therefrom driving instructions to enable positioning the at least one
container in a predetermined aligned position relative to the crane.
[0010] Thus, the system according to the invention combines knowledge of the tractor position
with a distance measurement between the tractor and the container in order to determine
the position of the container relative to the gantry crane with centimetre accuracy.
The tractor can for instance be the unit or part of the terminal truck that comprises
the engine and the driver cabin, but in case of an unmanned terminal truck can also
be the unit or part of the terminal truck that only comprises the engine, or the unit
or part of the terminal truck that comprises the engine and the battery in case of
an electrical unmanned terminal truck. It is important that the distance measurement
between tractor and container makes use of reflective technology wherein a signal
is sent from the reference point, line or plane near the tractor towards the container,
and its reflection on the container's front surface is captured and analysed to determine
the distance between the tractor and container. Such reflective technology is more
reliable than scanners, is not sensitive to weather conditions and also operates under
a crane. Compared to laser scanners, reflective technology like radars, lidars, etc.
are inexpensive and require low maintenance. In addition to the tractor position and
the distance between tractor and container, the system according to the invention
also gains knowledge on the type or the size of container that is carried by the terminal
truck. This information may for instance be received from the crane PLC that controls
movements of the crane spreader, or from another source external to the system according
to the invention. Knowledge of the tractor position, tractor-container distance, and
the type of container, enables to generate driving instructions for the terminal truck
to position the container in alignment with the vertical centre plane of the gantry
crane with centimetre accuracy. These driving instructions may be processed and transformed
for display or auditive playout to the terminal truck driver in order to assist the
terminal truck driver positioning the terminal truck. Alternatively, the driving instructions
may be processed and transformed into control signals for the steering unit of the
terminal truck in case of an unmanned terminal truck. Consequently, the crane spreader
can pick-up the container from the trailer and move it to the ship without any crane
displacement.
[0011] A container in the context of the present invention corresponds to any receptacle
or enclosure holding products, like for instance a shipping container used for international
transport and having standard lengths of 20 ft, 40 ft, 45ft.
[0012] A gantry crane in the context of the current invention refers to a container handling
crane located in the terminal of a port where containers are transferred. One example
of such gantry crane is a ship-to-shore crane, abbreviated STS crane, that transfers
containers from ship to shore or from a terminal truck to ship. Such gantry crane
typically has vertical supports, i.e. two sea-side supports and two land-side supports
moving along rails, horizontal beam, i.e. portal beams and sill beams, and a spreader
moving along the crane's boom under instruction of a crane controller or crane PLC.
[0013] A terminal truck in the context of the present invention represents any vehicle used
to move containers within a container terminal. The term "terminal truck" thus encompasses
an internal tractor vehicle, abbreviated ITV, but also may refer to a visiting truck
that is used on the terminal and moves containers. A terminal truck typically has
a tractor, that may alternatively be named a primer mover, a terminal tractor or a
yard truck, and a chassis or trailer designed and dimensioned to hold one or plural
containers. The trailer of a terminal truck typically has no locking pins to fix the
position of the container(s) it is holding. A single trailer may for instance be dimensioned
to hold a 45 ft container or alternatively hold two 20 ft containers. The terminal
truck may require the presence of a driver in a driver cabin to steer the vehicle
or alternatively may be an unmanned vehicle that moves autonomously under control
of a steering unit and sensors.
[0014] A receiver with connectivity to an external system in the context of the present
invention refers to any wireless receiver or transceiver, like for instance a Wifi
receiver, a Bluetooth receiver, a Zigbee receiver, etc. that connects wirelessly with
the transmitter of an external system wherein information is available indicative
for the container(s) held by the terminal truck. The external system may for instance
be a terminal operating system, abbreviated TOS, that controls the movement and storage
of various types of cargo in or around a container terminal or port.
[0015] In embodiments of the system according to the invention, as defined by claim 2, the
position determination unit comprises one or more micro location technology antenna,
abbreviated MLT antenna, mounted on the tractor.
[0016] Indeed, one or plural MLT antennas may for instance be roof-mounted on the terminal
truck's driver cabin or may be mounted on a pole aside the roof of the driver cabin
(in case of a manned terminal truck) or may be attached somewhere else to the tractor
like for instance a pole mounted on the tractor's chassis (in case for instance of
an unmanned terminal truck), and may be configured to determine the location of the
tractor relative to the gantry crane through radio-based location technology. Such
radio-based location technology achieves centimeter accuracy and has the advantage
to be less weather sensitive than laser scanners. Alternatively however, laser based
location technology may be deployed to determine the position of the terminal truck's
tractor under the crane.
[0017] In embodiments of the system according to the present invention, as defined by claim
3, the distance measurement unit comprises an ultrasound emitter and sensor.
[0018] Thus, a first sample reflective technology that could be deployed to measure the
distance between the reference point, line or plain near the tractor and the container's
front surface, comprises an ultrasound emitter and sensor. The ultrasound emitter
is located in or near the reference point, line or plane, for instance a vertical
reference plane through the center point of the terminal truck's cabin roof, and emits
an ultrasound signal in the direction from the tractor to the trailer holding one
or plural containers. The front surface of the first container reflects this ultrasound
signal partially or entirely and the reflections are captured by the ultrasound sensor
that is located also in or near the reference point, line or plane at the tractor.
By processing the emitted and reflected ultrasound signals, the distance from the
reference point, line or plane at the tractor to the front surface of the container
can be calculated with centimeter accuracy from the time difference between emitted
and reflected ultrasound signals. Knowledge of the type or the size of container further
enables to determine a reference point of the container, for instance the center point
of the container, such that driving instructions can be generated enabling to move
the terminal truck such that the reference point of the container becomes aligned
with the crane's spreader without displacement of the crane.
[0019] In alternate embodiments of the system according to the present invention, as defined
by claim 4, the distance measurement unit comprises a light detection and ranging
sensor, abbreviated Lidar sensor.
[0020] Thus, a second sample reflective technology that can be deployed to measure the distance
between the reference point, line or plane near the tractor and a container carried
by the trailer, comprises a Lidar sensor. Such Lidar sensor makes use of line-of-sight
technology, i.e. a light signal that is emitted in the direction of the trailer and
the reflections of which on the front surface of a container carried by the trailer
are captured. Again, measuring the time difference between emission of a light signal
and receipt of the corresponding reflected light signal enables to determine the distance
from the reference point, line or plane at the tractor to the container's front surface
with centimeter accuracy. Knowledge of the type or the size of container further enables
to determine the reference point of the container, for instance the center point,
such that driving instructions can be generated enabling to move the terminal truck
such that the reference point of the container becomes aligned with the crane's spreader
without displacement of the crane.
[0021] In further alternative embodiments of the system according to the present invention,
as defined by claim 5, the distance measurement unit comprises a radio detection and
ranging transmitter and receiver, abbreviated a radar transmitter and receiver.
[0022] Indeed, a third sample reflective technology that enables to determine the distance
between tractor and container located on the trailer relies on a radar. A radar transmitter
located in or near the reference point, line or plane at the tractor emits a radio
signal that is reflected on the front surface of the container. Measurement of the
time difference between emission of the radar signal and receipt of the corresponding
reflected radar signal enables to determine the distance between reference point,
line or plane and front surface of the container with centimeter accuracy. Knowledge
of the type of container or the size of container, as obtained from an external system,
allows to determine the location of a reference plane of the container, for instance
the center plane, such that driving instructions can be generated enabling to align
the reference plane of the container with the spreader of the crane without displacement
of the crane.
[0023] In embodiments of the system according to the present invention, defined by claim
6, the external system comprises a crane controller of said crane.
[0024] Thus, information directly or indirectly indicative for the size of the container
may be obtained from the crane controller or crane PLC. The latter may have obtained
such information from camera's scanning the container, or from a crane operator that
has entered the information.
[0025] In alternate embodiments of the system according to the invention, defined by claim
7, the external system comprises a terminal operating system, abbreviated TOS.
[0026] Indeed, information directly or indirectly indicative for the size of the container
located on the trailer of a terminal truck may also be obtained from a TOS, a system
that controls the movement and storage of various types of cargo in or around a container
terminal or port. The database that forms part of such TOS typically contains information
on the containers to be transported, like the size or the type of container, the container
ID, the goods contained therein, the status of the goods, etc.
[0027] In further alternate embodiments of the system according to the present invention,
defined by claim 8, the external system comprises a yard management system, abbreviated
YMS.
[0028] Thus, according to yet another alternative, information directly or indirectly indicative
for the size of the container(s) carried by a terminal truck may be obtained from
a yard management system. Such YMS is a software system that oversees the movement
of trucks and trailers in the yard of a production facility, distribution center,
warehouse, etc.
[0029] In embodiments of the system according to the invention, defined by claim 9, the
container information comprises the type of the at least one container.
[0030] Indeed, shipping containers used for international transport are standardized by
an ISO standard. Containers of different sizes have different container type codes.
If the information obtained from the external system comprises the standardized container
type code, the system according to the present invention can determine therefrom the
size or length of the container. Knowledge of the location of the tractor, the distance
from the tractor to the front surface of the container and the length or the size
of the container, allows to determine the location of a reference plane of the container,
for instance the center plane, on the trailer of the terminal truck. Using the location
of the reference plane of the container, the system can then generate driving instructions
enabling to align this reference plane with the crane's spreader.
[0031] In alternate embodiments of the system according to the present invention, defined
by claim 10, the container information comprises the size of the at least one container.
[0032] Indeed, instead of obtaining information like the type of container that indirectly
indicates the size or length of the container(s) carried by a terminal truck, embodiments
of the present invention may obtain information that is directly indicative for the
size or length of the container(s) when such information is available in the external
system where it connects to. The information may for instance represent the length
of the container in ft, like for instance 20 ft, 40 ft, 45 ft, ...
[0033] In embodiments of the system according to the present invention, defined by claim
11, the distance is measured with an accuracy of 10 centimeters or shorter.
[0034] The spreader of a gantry crane typically has flaps as a result of which the tolerance
on the alignment of the container to be picked-up relative to the crane amounts to
10 centimeters. The sum of errors, which is the cumulated error from the tractor position
determination and echo based distance measurement, should be less than 10 centimeters.
Consequently, the distance between tractor and front surface of the container must
be determined with an accuracy that is smaller than 10 centimeters.
[0035] In embodiments of the system according to the present invention, as defined by claim
12, the position determination unit and the distance measurement unit are integrated
in a single housing.
[0036] Hence, preferred embodiments of the invention integrate the technology used to determine
the location of the tractor like for instance one or plural MLT antennas and the technology
used to determine the distance from the tractor to the container like for instance
radar, lidar or ultrasound transmitters and emitters, in a single housing that can
for instance be roof-mounted on the roof of the driver cabin, or that can be attached
elsewhere to the tractor. The tractor of each terminal truck operating in a port can
be equipped with such a module. The wireless receiver that connects with the external
system to obtain information indicative for the container size may also be integrated
in this housing, or alternatively may form part of an on-board module that also holds
the computing unit that generates the driving instructions for the terminal truck
driver or for the steering unit of the terminal truck. This on-board module may comprise
a display and/or a loudspeaker to generate visible and/or audible instructions for
the driver, or alternatively may comprise a processor that generates signalling for
the steering unit in case the terminal truck is an unmanned vehicle. It is however
noticed that in alternative embodiments, the different components of the system according
to the invention may not be integrated in a single housing. The position determination
unit may for instance comprise two or more antennas that must be spaced apart and
therefore preferably become integrated in different housings that are positioned on
or near the tractor.
[0037] In embodiments of the system according to the present invention, as defined by claim
13, the reference point, line or plane corresponds to the center plane through an
MLT antenna of the one or more MLT antenna.
[0038] In particular when MLT antenna(s) and the reflective distance measurement technology
are integrated in a single housing, the reference point, line or plane from which
the distance is measured towards the front surface of the container may be selected
to correspond with a center point, center line or center plane of one of the MLT antenna(s).
This further simplifies calculation of the position of the container.
[0039] In addition to a system as defined by claim 1, the present invention also relates
to a corresponding method as defined by claim 14, enabling alignment of a terminal
truck relative to a gantry crane, the terminal truck comprising a tractor and a trailer
holding at least one container to be picked up by the crane, the method comprising:
- determining a tractor position for the tractor relative to the crane;
- receiving from an external system container information indicative for the size of
the at least one container;
- measuring a distance between a reference point, line or plane at the tractor and a
front surface of the at least one container based on reflective technology; and
- generating from the tractor position, the container information, and the distance
driving instructions to enable positioning the at least one container in a predetermined
aligned position relative to the crane.
Brief Description of the Drawings
[0040]
Fig. 1 illustrates an embodiment of the system and method for alignment of a terminal
truck relative to a ship-to-shore crane according to the present invention;
Fig. 2 is a functional block scheme of an embodiment of the system for alignment of
a terminal truck relative to a ship-to-shore crane according to the present invention;
and
Fig. 3 illustrates a suitable computing system 300 for realizing portions of the system
and method according to embodiments of the invention.
Detailed Description of Embodiment(s)
[0041] Fig. 1 shows a ship-to-shore crane or STS crane having four vertical supports 101,
102, 103 and 104, and four horizontal beams 105, 106, 107 and 108. Such STS crane
typically has two horizontal sill beams 107 and 108 that are located at a height of
6 meters and two horizontal portal beams 105 and 106 that are located at a height
of 13 to 16 meters. The portal beams 105 and 106 are oriented parallel to the crane's
boom 150 whereas the sill beams 107 and 108 are oriented perpendicular thereto. Along
the crane's boom 150, a spreader 151 is moving to carry and transfer containers, e.g.
from a ship to a truck, or vice versa. The present invention in particular concerns
transfers of containers from a terminal truck to a ship. As mentioned, the STS crane
further has four vertical supports of which 101 and 102 represent the sea-side supports
and 103 and 104 represent the land-side supports. Such STS crane is used in ports
as a result of which the crane is typically designed to have an operational wind load
of 25 m/s, to have a breakdown wind load of 50 m/s, to function within a temperature
range from -20 °C up to 50 °C, and at a humidity of up to 100 %. The STS crane is
typically positioned on rails, not shown in Fig. 1, such that the STS crane can be
moved in the direction parallel to the quay border, i.e. the direction of the sill
beams 107, 108. Movements of the STS crane along the rails and movements of the spreader
151 along the crane's boom 150 to transfer a container are controlled by a crane controller
or PLC.
[0042] Fig. 1 further shows three driving lanes 161, 162 and 163 under the STS crane, and
three terminal trucks 110, 120 and 130 located respectively in driving lanes 161,
162 and 163, and carrying one or plural containers to be picked up by the spreader
151 of the STS crane for transfer to a ship. In driving lane 161, a first terminal
truck 110 with tractor 111 and trailer 112 is located. The trailer 112 is carrying
a single 20 ft container 113 that must be transferred to the ship. In driving lane
162, a second terminal truck 120 with tractor 121 and trailer 122 is located. The
trailer 122 is carrying two 20 ft containers 123 and 124 that must be transferred
to the ship. In driving lane 163, a third terminal truck 130 with tractor 131 and
trailer 132 is located. The trailer 132 is carrying a single 45 ft container 133 that
must be transferred to the ship.
[0043] To avoid or minimize translation of the crane along the rails in order to align the
crane's boom 150 and spreader 151 with the container to be transferred, the terminal
trucks 110, 120 and 130 are equipped with a system that assists in alignment of the
terminal truck with the crane, more particularly in alignment of the container to
be transferred with the crane's boom 150 and spreader 151. The alignment assistance
system comprises a roof-mounted module, i.e. a module that is attached to the roof
of the terminal truck's cabin, and an on-board module, i.e. a module that is located
on-board of the terminal truck cabin, typically within the visible range of the terminal
truck driver. Alternatively, when the terminal truck is an unmanned vehicle, the first
module may be mounted on the tractor, for example on a vertical pole, and the second
module may be a processing module that connects with the steering unit of the unmanned
vehicle. In the example of Fig. 1, the terminal trucks 110, 120 and 130 are assumed
to be manned vehicles whose respective tractors 111, 121, 131 also comprise a driver
cabin whereon the first module can be roof-mounted. As such, the first terminal truck
110 shown in Fig. 1 is equipped with a roof-mounted module 115 and an on-board module
118 that are interconnected through a wireline or wireless connection. The second
terminal truck 120 shown in Fig. 1 is equipped with a roof-mounted module 125 and
an on-board module 128 that are interconnected through a wireline or wireless connection.
The third terminal truck 130 shown in Fig. 1 is also equipped with a roof-mounted
module 135 and an on-board module 138 that are interconnected through a wireline or
wireless connection.
[0044] The alignment assistance system 115, 118 comprises technology that enables to determine
the position of the tractor 111 relative to the crane, more precisely to determine
the position of centre line 116 of the roof-mounted module 115 relative to centre
line 152 of the crane's boom 150. The alignment assistance system 115, 118 further
comprises technology that enables to determine the distance from the tractor 111 to
the container 113 on the trailer 112, more precisely to determine the distance 117
from the centre line 116 of the roof-mounted module 115 to the front surface of container
113. The alignment assistance system 115, 118 further comprises technology that enables
to gain knowledge on the size of container 113, more precisely to obtain information
indicative for the length of container 113. Knowing the position of the tractor 111,
the distance between tractor 111 and container 113, and the size of the container
113, the alignment assistance system 115, 118 can generate instructions for the driver
allowing the driver to move truck 110 forward or backward in lane 161 until the centre
line 119 of container 113 is aligned - within acceptable tolerances that may range
up to 10 centimetres - with the centre line 152 of the crane's boom 150. Consequently,
the crane no longer needs to be translated along its rails in order to enable pick-up
of the container 113 as a result of which the terminal efficiency increases.
[0045] Similarly, the alignment assistance system 125, 128 comprises technology that enables
to determine the position of the tractor 121 relative to the crane, more precisely
to determine the position of centre line 126 of the roof-mounted module 125 relative
to centre line 152 of the crane's boom 150. The alignment assistance system 125, 128
further comprises technology that enables to determine the distance from the tractor
121 to the first container 123 on the trailer 122, more precisely to determine the
distance 127 from the centre line 126 of the roof-mounted module 125 to the front
surface of this first container 123. The alignment assistance system 125, 128 further
comprises technology that enables to gain knowledge on the size of container 123,
more precisely to obtain information indicative for the length of container 123. Knowing
the position of the tractor 121, the distance between tractor 121 and container 123,
and the size of the container 123, the alignment assistance system 125, 128 can generate
instructions allowing the driver to move truck 120 forward or backward in lane 162
until the centre line 129 of container 123 is aligned - within acceptable tolerances
that may range up to 10 centimetres - with the centre line 152 of the crane's boom
150. Consequently, the crane no longer needs to be translated along its rails in order
to enable pick-up of the container 123 as a result of which the terminal efficiency
increases. Once container 123 has been transferred to the ship, the alignment assistance
system 125, 128 is used to determine the position of the second container 124 on trailer
122 relative to the crane and to obtain information indicative for the length of this
second container 124. Knowing the relative position of the second container 124 and
the length of this container 124, the alignment assistance system 125, 128 can generate
driving instructions enabling the driver to move truck 120 forward and backward until
the second container 124 is aligned - within acceptable tolerances that may range
up to 10 centimetres - with the centre line 152 of the crane's boom 150. Also for
pick-up of the second container 124 carried by the same trailer 122, the crane need
not be translated along its rails, further enhancing the efficiency of the terminal.
[0046] Further similarly, the alignment assistance system 135, 138 comprises technology
that enables to determine the position of the tractor 131 relative to the crane, more
precisely to determine the position of centre line 136 of the roof-mounted module
135 relative to centre line 152 of the crane's boom 150. The alignment assistance
system 135, 138 further comprises technology that enables to determine the distance
from the tractor 131 to the container 133 on the trailer 132, more precisely to determine
the distance 137 from the centre line 136 of the roof-mounted module 135 to the front
surface of container 133. The alignment assistance system 135, 138 further comprises
technology that enables to gain knowledge on the size of container 133, more precisely
to obtain information indicative for the length of container 133, i.e. 45 ft. Knowing
the position of the tractor 131, the distance between tractor 131 and container 133,
and the size of the container 133, the alignment assistance system 135, 138 can generate
instructions allowing the driver to move truck 130 forward or backward in lane 163
until the centre line 139 of container 133 is aligned - within acceptable tolerances
that may range up to 10 centimetres - with the centre line 152 of the crane's boom
150. Consequently, the crane no longer needs to be translated along its rails in order
to enable pick-up of the container 133 as a result of which the terminal efficiency
further increases.
[0047] The technology present in the roof-mounted modules 115, 125, 135 and in the on-board
modules 118, 128, 138 of the above described alignment assistance systems is described
in more detail with reference to Fig. 2 where the alignment assistance system is denoted
200. Herein, 201 represents a sample implementation of the roof-mounted modules 115,
125 and 135, and 202 represents a sample implementation of the on-board modules 118,
128 and 138. The roof-mounted module 201 and on-board module 202 are interconnected
through a cable 203. In alternative embodiments of the invention, the interconnection
may be wireless. The roof-mounted module 201 comprises a first Micro-Location Technology
antenna or MLT antenna 211 and a second MLT antenna 212. The MLT antenna's 211 and
212 capture signals of one or more beacon located in the terminal area, enabling to
accurately determine the position of the centre line of roof-mounted module 201 relative
to the centre line of the boom of the crane located in the terminal. Alternative position
determination technologies may be deployed to determine the position of the roof-mounted
module 201 relative to the crane, like for instance GPS or laser scanners, provided
that these technologies reach an accuracy of at most a few centimetres, and provided
that these technologies operate reliably under the crane and in difficult weather
conditions. The signals captured by the MLT antennas 211 and 212 are transferred to
a computing unit 223 in on-board module 202. The roof-mounted module 201 further comprises
an ultrasound transmitter 213, configured to generate on instruction of the computing
unit 223 an ultrasound signal 231 that is emitted in the direction from tractor to
trailer. The roof-mounted module 201 further also comprises an ultrasound receiver
214 able to capture the reflected ultrasound signal 232 that results from reflection
of ultrasound signal 231 on the front surface of a container carried by the trailer.
The time of transmission of ultrasound signal 231 and the time of receipt of ultrasound
signal 232 are reported to the computing unit 223. Alternative implementations of
the roof-mounted module may rely on different reflective technologies, like for instance
radar technology or Lidar technology, provided these technologies reach an acceptable
accuracy of at most a few centimetres, and provided these reflective technologies
work properly under a crane in difficult weather conditions. The on-board module 202
in addition to the computing unit 223 also comprises a WiFi transceiver 221 that is
configured to communicate with the crane controller, or alternatively with a terminal
operating system or yard management system to obtain therefrom information indicative
for the length of the container or containers carried by the trailer. The information
may comprise a container code, a container size, a container size code, etc. This
information is transferred to the container information receiver 222 in on-board module
202 to enable extraction of the length of the container that is located upfront on
the trailer, i.e. the container whose front surface has reflected ultrasound signal
231. The length of the container as determined by the container information receiver
222 is reported to computing unit 223. Computing unit 223 is configured with a software
program to determine the distance from the centre line of roof-mounted module 201
to the centre line of the crane's boom from the signalling obtained from MLT antennas
211 and 212. Computing unit 223 is further configured with software code to determine
the distance from the centre line of the roof-mounted module 201 to the front surface
of the container that reflected ultrasound signal 231 from the time information received
from ultrasound transmitter 213 and ultrasound receiver 232. Using the distance D1
between the centre line of roof-mounted module 201 and the centre line of the crane's
boom, the distance D2 between the centre-line of the roof-mounted module 201, and
the length L of the container, the processor can generate instructions for the driver
to move the terminal truck either forward or backward. As long as D1 is greater than
D2 + L/2, the terminal truck must be moved backward. As long as D1 is smaller than
D2 + L/2, the terminal truck must be moved forward. The so generated instructions
can be communicated audibly to the driver via speaker 225 or visibly through display
224. The measurement and generation of instructions is repeated iteratively until
the terminal truck is aligned with the crane, which is achieved when D1 = D2 + L/2
within acceptable tolerances.
[0048] Fig. 3 shows a suitable computing system 300 enabling to implement embodiments of
the computing unit 223 that is used in embodiments of the invention. Computing system
300 may in general be formed as a suitable general-purpose computer and comprise a
bus 310, a processor 302, a local memory 304, one or more optional input interfaces
314, one or more optional output interfaces 316, a communication interface 312, a
storage element interface 306, and one or more storage elements 308. Bus 310 may comprise
one or more conductors that permit communication among the components of the computing
system 300. Processor 302 may include any type of conventional processor or microprocessor
that interprets and executes programming instructions. Local memory 304 may include
a random-access memory (RAM) or another type of dynamic storage device that stores
information and instructions for execution by processor 302 and/or a read only memory
(ROM) or another type of static storage device that stores static information and
instructions for use by processor 302. Input interface 314 may comprise one or more
conventional mechanisms that permit an operator or user to input information to the
computing unit 300, such as a keyboard 320, a mouse 330, a pen, voice recognition
and/or biometric mechanisms, a camera, etc. Output interface 316 may comprise one
or more conventional mechanisms that output information to the operator or user, such
as a display 340, etc. Communication interface 312 may comprise any transceiver-like
mechanism such as for example one or more Ethernet interfaces that enables computing
system 300 to communicate with other devices and/or systems, for example with other
computing units 381, 382, 383. The communication interface 312 of computing system
300 may be connected to such another computing system by means of a local area network
(LAN) or a wide area network (WAN) such as for example the internet. Storage element
interface 306 may comprise a storage interface such as for example a Serial Advanced
Technology Attachment (SATA) interface or a Small Computer System Interface (SCSI)
for connecting bus 310 to one or more storage elements 308, such as one or more local
disks, for example SATA disk drives, and control the reading and writing of data to
and/or from these storage elements 308. Although the storage element(s) 308 above
is/are described as a local disk, in general any other suitable computer-readable
media such as a removable magnetic disk, optical storage media such as a CD or DVD,
-ROM disk, solid state drives, flash memory cards, ... could be used. It is noticed
that the entire method according to the present invention can be executed centralized,
e.g. on a server in a management centre or in a cloud system, or it can be partially
executed on a remote electronic device, e.g. worn by the user, and partially on a
central server. Computing system 300 could thus correspond to the processing system
available centrally or the processing system available in the electronic device.
[0049] Although the present invention has been illustrated by reference to specific embodiments,
it will be apparent to those skilled in the art that the invention is not limited
to the details of the foregoing illustrative embodiments, and that the present invention
may be embodied with various changes and modifications without departing from the
scope thereof. The present embodiments are therefore to be considered in all respects
as illustrative and not restrictive, the scope of the invention being indicated by
the appended claims rather than by the foregoing description, and all changes which
come within the meaning and range of equivalency of the claims are therefore intended
to be embraced therein. In other words, it is contemplated to cover any and all modifications,
variations or equivalents that fall within the scope of the basic underlying principles
and whose essential attributes are claimed in this patent application. It will furthermore
be understood by the reader of this patent application that the words "comprising"
or "comprise" do not exclude other elements or steps, that the words "a" or "an" do
not exclude a plurality, and that a single element, such as a computer system, a processor,
or another integrated unit may fulfil the functions of several means recited in the
claims. Any reference signs in the claims shall not be construed as limiting the respective
claims concerned. The terms "first", "second", third", "a", "b", "c", and the like,
when used in the description or in the claims are introduced to distinguish between
similar elements or steps and are not necessarily describing a sequential or chronological
order. Similarly, the terms "top", "bottom", "over", "under", and the like are introduced
for descriptive purposes and not necessarily to denote relative positions. It is to
be understood that the terms so used are interchangeable under appropriate circumstances
and embodiments of the invention are capable of operating according to the present
invention in other sequences, or in orientations different from the one(s) described
or illustrated above.
1. A system (115, 118; 125, 128; 135, 138; 200) enabling alignment of a terminal truck
(110; 120; 130) relative to a gantry crane (101-108, 150, 151), said terminal truck
(110; 120; 130) comprising a tractor (111; 121; 131) and a trailer (112; 122; 132)
holding at least one container (113; 123, 124; 133) to be picked up by said crane
(101 - 108, 150, 151), said system (115, 118; 125, 128; 135, 138; 200) comprising:
- a position determination unit (211, 212) configured to determine a tractor position
for said tractor (111; 121; 131) relative to said crane (101-108, 150, 151);
- a receiver (221, 222) with connectivity to an external system, said receiver (221,
222) being configured to receive from said external system container information indicative
for the size of said at least one container (113; 123, 124; 133);
- a distance measurement unit (213, 214) configured to measure a distance (117; 127;
137) between a reference point, line or plane (116; 126; 136) at said tractor (111;
121; 131) and a front surface of said at least one container (113; 123, 124; 133)
based on reflective technology; and
- a computing unit (223) coupled to said position determination unit (211, 212), said
receiver (221, 222) and said distance measurement unit (213, 214), said computing
unit (223) being configured to collect said tractor position, said container information,
and said distance, and further being configured to generate therefrom driving instructions
to enable positioning said at least one container (113; 123, 124; 133) in a predetermined
aligned position relative to said crane (101-108, 150, 151).
2. The system (115, 118; 125, 128; 135, 138; 200) according to claim 1, wherein said
position determination unit (211, 212) comprises one or more micro location technology
antenna, abbreviated MLT antenna, mounted on said tractor (111; 121; 131).
3. The system (115, 118; 125, 128; 135, 138; 200) according to claim 1 or claim 2, wherein
said distance measurement unit (213, 214) comprises an ultrasound emitter (213) and
sensor (214).
4. The system (115, 118; 125, 128; 135, 138; 200) according to claim 1 or claim 2, wherein
said distance measurement unit comprises a light detection and ranging sensor, abbreviated
Lidar sensor.
5. The system (115, 118; 125, 128; 135, 138; 200) according to claim 1 or claim 2, wherein
said distance measurement unit comprises a radio detection and ranging transmitter
and receiver, abbreviated a radar transmitter and receiver.
6. The system (115, 118; 125, 128; 135, 138; 200) according to one of claims 1-5, wherein
said external system comprises a crane controller of said crane (101-108, 150, 151).
7. The system (115, 118; 125, 128; 135, 138; 200) according to one of claims 1-5, wherein
said external system comprises a terminal operating system, abbreviated TOS.
8. The system (115, 118; 125, 128; 135, 138; 200) according to one of claims 1-5, wherein
said external system comprises a yard management system, abbreviated YMS.
9. The system (115, 118; 125, 128; 135, 138; 200) according to one of claims 1-8, wherein
said container information comprises the type of said at least one container.
10. The system (115, 118; 125, 128; 135, 138; 200) according to one of claims 1-8, wherein
said container information comprises the size of said at least one container.
11. The system (115, 118; 125, 128; 135, 138; 200) according to one of the preceding claims,
wherein said distance is measured with an accuracy of 10 centimeters or shorter.
12. The system (115, 118; 125, 128; 135, 138; 200) according to one of the preceding claims,
wherein said position determination unit (211, 212) and said distance measurement
unit (213, 214) are integrated in a single housing (115; 125; 135; 201).
13. The system (115, 118; 125, 128; 135, 138; 200) according to claim 2, wherein said
reference point, line or plane (116; 126; 136) corresponds to the center plane through
an MLT antenna of said one or more MLT antenna.
14. A method enabling alignment of a terminal truck (110; 120; 130) relative to a gantry
crane (101-108, 150, 151), said terminal truck (110; 120; 130) comprising a tractor
(111; 121; 131)and a trailer (112; 122; 132) holding at least one container (113;
123, 124; 133) to be picked up by said crane (101-108, 150, 151), said method comprising:
- determining a tractor position for said tractor (111; 121; 131) relative to said
crane (101-108, 150, 151);
- receiving from an external system container information indicative for the size
of said at least one container (113; 123, 124; 133);
- measuring a distance (117; 127; 137) between a reference point, line or plane (116;
126; 136) at said tractor (111; 121; 131) and a front surface of said at least one
container (113; 123, 124; 133) based on reflective technology; and
- generating from said tractor position, said container information, and said distance
driving instructions to enable positioning said at least one container (113; 123,
124; 133) in a predetermined aligned position relative to said crane (101-108, 150,
151).