Instrumentation & Measurement Magazine 24-4 - 70

Table 1 - The difference of VBM technology applications in a container terminal and a factory
Container terminal operation
Factory operation
Environment is difficult to control, there is a lot of
moisture and dust in the air
Environment
Light conditions will change with the weather
conditions
Vibration generated by heavy equipment in the
terminal will cause interference to the equipment
Task
Vision field
VBM system in a container terminal is used for
process control by measurement data
The measurement areas to be covered are too
large, need multiple cameras to capture all
measurement areas
Performance
Camera type
High performance requirements; the unstable
environment of the container terminal and
multi-camera data increase the performance
requirements of the image processor
Usually use universal camera to capture normal
images
The environmental impact is well controlled, indoor
air quality is good
Light conditions are stable
Vibration interference is negligible
VBM system in a factory used for data acquisition
and analysis and little or no process control
Measurement areas to be covered are not large; only
one or a few cameras are needed
Low performance requirements; the stable
environment and small vision field in the factory
make the algorithm simpler and reduces the
performance requirements of the image processor
Usually use dedicated camera, and choose different
forms for different recognition objects
Application
Container surface damage detection
Container positioning
Container number detection
Truck positioning
Truck anti lifting
Truck number detection
AGV guidance
Human detection
Cargo holds detection
Spreader positioning
Table 2 - The Applications of VBM in ACT
Target
Container
Container
Container number
Container truck
Truck chassis
Truck number
Environment around AGV
Humans in some important areas
Cargo holds in container ship
Spreader
process optimization. The VBM system is often used as an
information acquisition channel for digital management systems.
Consider the VBM systems in ARMG as an example
(Fig. 10). RMG is controlled by an automatic crane control system
(ACCS), and its task is to transfer the container to the yard
block. An optical character recognition (OCR) system is used
to recognize the information of the container, a chassis positioning
system (CPS) is used to load and unload containers
from the container truck or container yard, and a security control
system (SCS) is used to detect accidents during operation.
The common process in container handling operation is
as follows: the container number data detected by the OCR
system is sent to the block management system (BMS) for recording
and comparison with the data in the mission plan.
After confirming its accuracy, the spreader is adjusted through
the CPS data, and the truck driver is guided to adjust the position
of the truck for container loading and unloading. During
70
Measuring object
Deformation and holes on the container surface
Container position
Truck position
Chassis position
AGV position and orientation
Human position
Cargo holds or container position
Spreader position
the entire operation, the SCS sends a signal to the ACCS to stop
the operation if it detects that an accident has occurred. The
staff can control the entire process through the control terminal
in the remote control room when an accident occurs or the
system fails. They can also control the RMG manually through
the console terminal.
Chassis Positioning System: CPS is a typical application of
VBM in ACT. It combines the information obtained by the VBM
system with automatic control technology to significantly increase
the speed of connecting the spreader to the container.
The installation of the CPS is shown in Fig. 11. The system uses
cameras that are installed on ARMG to measure the position
data of AGV or container trucks and sends the measured data
to the ACCS. According to the measured data, the ACCS will
use programmable logic controller (PLC) to move the spreader
to the true position. If the transportation vehicle is a container
IEEE Instrumentation & Measurement Magazine
June 2021
Instrumentation & Measurement Magazine 24-4

Table of Contents for the Digital Edition of Instrumentation & Measurement Magazine 24-4
