Container-Positioning System For Port Terminals (Pds)

The PDS (position-detecting system) consists of an electronic system determined at all times by the coordinates of the crane spreader

Whenever the container-movement operations at a terminal are being automated, it is advisable to install a PDS system on each rubber-wheeled gantry crane for the loading and unloading of containers.

SICEs PDS can be adapted to gantry cranes for containers with now-outdated electrical controls, such as those based on the Ward-Leonard system, or PLC controls by many different manufacturers (e.g. GE, ABB, etc.).

Given the wide variety of different controls and manufacturers found on the cranes at most terminals, SICEs PDS is a system that is independent of the crane-movement controls, although use can usually be made of information obtained from the crane-control relays or PLC.

Containers are stacked in long rows, interrupted by cross lanes, known as lane sections. TAGs sited at the beginning and end of each lane section give information on the lane number and current block via radio to the antennas.

A key feature of SICEs PDS, which enables the automation of terminal operations to be extended further, is that it contains a TAG-reading antenna with the relevant assigned number.

The antenna case's microprocessor module prepares a data packet carrying truck and ground TAG readings, together with the count by the X-coordinate encoder. This data packet is sent in series via Optoflex fibre-optic cable (FO) to the microprocessor module in the drivers cab.

With the data from the TAG readings and X encoder in the packet from the antenna case and the reading of the carriage encoder, Y coordinate, elevation, and Z coordinate, plus such digital signals as open and closed Twistlocks, gantry-crane wheels in normal operating position, etc., that reach microprocessor case in the cab, this module creates a data packet containing all the above information which is sent in series to the PC-display-WiFi array.

SICEs PDS supply includes in each case the specific power sources for its electronic modules and interface cards, encoder, and ground and truck TAG-reading antennas.

The environment in which the PDS is installed, powered by the crane itself, featuring large AC/DC or AC/AC converters of movements by motors and controls (contactors, solenoids and other apparatus and equipment), is a source of wide-spectrum RFI noise. The PDS includes measures to impede the transmission to the electronic modules or computer of any electrical noise that could affect reliability. These measures consist of:

• Use of ultra-insulated transformers to supply the power sources and impede the transmission of noise at frequencies under 100 Khz.
• Use of RFI filters outside and inside the power sources to reduce the transmission of RFI noise at frequencies above 100 Khz.
• Use of decoupling condensers in electronic cards

To deal with the large-magnitude radiated noise surrounding cranes at container terminals by the profusion of voice transmitters, radar pulses from ships or navy bases, etc., the electronic modules are housed inside metal chests with metal-coated flexible joints provided for doors and wave guides to access the interior wiring.

SICE supplies the PDS with components featuring consolidated technology to assure the reliability of the system and its operation, although in the future they will be upgraded and replaced by other, equally proven, components, apparatus or technical concepts. The computer in the PC-display-WiFi array must run specific software for each management system at the container terminal (CATOS, NAAVY, Cosmos, etc.) to receive commands sent via WiFi by the operations computer, for containers in the stacks shown on the display together with other additional information, allowing the operations to be carried out if the lane, spreader position and truck-number data fall within the acceptable margins set by the PDS. Whenever a manoeuvre is completed the terminal's operations computer is informed of all the relevant details via WiFi.