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PAI-PL, the innovation for level crossing safety

PAI-PL, the innovation for level crossing safety

PAI-PL (Automatic Integrative Protection of Level Crossings) is the name of an innovative auxiliary technology dedicated to the detection of obstacles present in railway Level Crossings, in the area delimited by the barriers. Based on laser or radar systems, it is capable of preventing the risk of impact between trains and any vehicles that, stationary or moving, occupy the interior of the monitored area during barrier closure.

GCF's proprietary Level Crossing Protection (LCP) System for radar-type PAI-PL applications is a SIL 4, absolute safety system, qualified in accordance with the RFI DTCSTSSSTB SR IS 05 001 C specification and already compliant with the latest RFI DT ST SCCS IT IS 092 268 A standards.

Installation flexibility makes it suitable even for "difficult" situations; radar technology ensures its effectiveness even in extreme weather conditions. Installation does not require onerous civil works.

Reliable and inexpensive, it does not require human intervention: it can detect any obstacle of size from 40 cm and, in case, it acts automatically on the signalling system by sending the "Obstructed route" signal. To the benefit of safety.

PAI-PL, technology at the service of security

Level Crossing Protection (LCP) is a radar technology PAI-PL system designed for automatic crossing control of level crossings equipped with complete barriers. Its purpose is to detect the presence of obstacles trapped inside the level crossing during barrier closure, thereby preventing the risk of collisions between vehicles and trains and ensuring the safety of level crossings.

LCP performs monitoring of the PL area by means of radar sensors installed on special support posts that are in turn connected to a fail-safe control logic that relates to the Signalling System (IS).

When the level crossing barriers close, the radar sensors scan the PL area, and if an obstacle is found, the system's control logic will fail-safe the consent signal to the Signalling Plant, which will prevent the train from passing.
In its "standard" configuration, the proprietary GCF LCP 3.0 System consists of 6 subsystems:

LCP GCF Subsystems

PL Area Monitoring Subsystem (SSM). Installed at the yard on special posts, it consists essentially of radar sensors dedicated to safely detect the occupancy/freedom status of the level crossing area by detecting any obstacles.

Processing Subsystem (SSE). Fail-safe logical unit that collects and processes information transmitted by one or more SSMs and handles interfacing with Signalling equipment.

Video Acquisition Subsystem (SSAV). Consisting of one or more cameras and the management software installed on the industrial PC inside the cabinet.

Data Collection Subsystem (SSRD). Consisting of PCs and devices/software needed to collect/store data from ESS and SSAV and transmit them to the Central Post Subsystem.

Central Post Subsystem (SSPC). Consisting of a server that handles the storage of information and the clients that display it to the operators. Allows supervision of the various PAI-PL systems on line (maximum 300 systems, even from different suppliers) connected via Client Server architecture.

Diagnostic Subsystem consisting of the Tools and instruments that allow configuration, functional verification and data download from the Processing Subsystem.

The radar technology option, small size of system elements, interoperability features, and Client-Server architecture such that it is compatible with other PAI-PL technology systems are qualifying and measurable competitive advantages in terms of flexibility, cost-effectiveness, reliability.


PAI-PL System Configuration

Radar pole

Immune to atmospheric events

Radar pole

Sensors Radar at 77GHz
Large field of view (FOV)

Signalling

Signal of "Prevented Way"

LCP cabinet

Signalling interface

Stuck train

Automatic train block

Reference Object

Off-grid
For radar self-calibration

Reference Object

Off-grid
For radar self-calibration

Monitored area

Monitored area: up to 370sqm
Obstacles detected: from 40 cm

Video acquisition system

IP camera
Streaming to central server
  • Radar pole

    Immune to atmospheric events
  • Radar pole

    Sensors Radar at 77GHz
    Large field of view (FOV)
  • Signalling

    Signal of "Prevented Way"
  • LCP cabinet

    Signalling interface
  • Stuck train

    Automatic train block
  • Reference Object

    Off-grid
    For radar self-calibration
  • Reference Object

    Off-grid
    For radar self-calibration
  • Monitored area

    Monitored area: up to 370sqm
    Obstacles detected: from 40 cm
  • Video acquisition system

    IP camera
    Streaming to central server

The Monitoring Subsystem (SSM)

It is typically composed of a pair of radar poles and 2 Reference Objects.
The radar poles contain the power electronics and optical junctions in the rear and are equipped with 77GHz radar sensors in the front that constantly scan the PL area and, via fibre-optic connection, transmit information to the LCP Cabinet.

The radar poles, which can be extended to 4 elements if necessary, are flanked by 2 to 4 "Reference Objects": laid outside the PL area the "reference targets," totally passive elements (without power supply), allow the system to self-calibrate, diagnosing and ensuring the correct operation of the equipment.

In addition, the system provides for the installation at the yard, on a VTR pole up to 5 m high, of an auxiliary "camera kit" which, consisting essentially of an IP camera and a power supply box, provides for the continuous transmission of images of the PL area to the Central Server. From the Movement Office, it is thus possible, if necessary, to monitor the PL live and verify the causes for which the system has autonomously activated an automatic blockade of railway traffic.

The radar poles, on a 1-meter-high metal structure, are fixed at approximately the same elevation as the plane of the iron, on special concrete slabs designed to prevent the growth of vegetation in front of the sensors. The monitoring area is precisely identified and marked by affixing special yellow curbs at the edge of the roadway.

Pai Pl GCF LCP

The Processing Subsystem (ESS)

The second element of the LCP system, carries out the processing of information transmitted, via optical fibre, from one or more Monitoring Subsystems, managing the interfacing with the signalling system. It is located in an LCP Cabinet, usually installed in the spaces adjoining the PL, where Power Cables and MultiMode Fiber are also located, and is connected to the Central Post via 8x1 IS cable, power cable and singleMode fibre (the Line connections).

It constitutes the real "heart" of the system: connected via Optical Fiber with Radar Poles, Ip camera and Central Post; Receives the PL closure signal (KPL contacts); scans the PL area thanks to the radar poles; decides whether to grant the consent signal (CsPAI); manages the alarm relay (AllPAI); through the Data Collection Subsystem (SSRD) provides local LOG and video storage.

Central Place (PCCS

It is the centralized location that allows the supervision of several PAI-PL Installations (maximum 300 installations, even from different suppliers) by exposing the information to the Movement and Maintenance personnel via Client Server architecture. In practice, at the Movement Office (Unified Location), a Master Server receives data from all PAI-PLs installed in the section and is able to represent them on a single monitor, avoiding the proliferation of monitors in the Movement Office.

Total Compatibility. GCF's PCCS complies with the IT268 interoperability standard, which allows information to be shared with other vendors' PCCSs by installing in Movement Offices a single workstation for all PLs in the route.

PAI-PL GCF's Data Network


The Advantages of Radar Technology

The use of automotive-derived radar technology (it uses the same sensors installed in self-driving cars) provides total immunity with respect to optical refraction problems that, in adverse weather conditions, can disrupt the reliability of laser technologies. Their high sampling rate makes radar sensors reliable and efficient at any time of year and in any climatic context. The LCP system is tested to withstand extreme weather conditions: it continues to operate in rainfall up to 100 mm/h (100 lt/h) per sq. m., in snowfall (tested with accumulations up to 30 cm) and in fog even when there is zero horizontal visibility.

  • Wide field of view (FOV)
  • Flexible Installation
  • Durable over time
  • Low consumption
  • Wide field of view (FOV)

    Wide field of view (FOV)

    The wide FOV (Field of View) of the radar sensors enables the safe monitoring of areas up to 370 sq. m. wide, 3 times larger than the 105 sq. m. extension required by RFI specifications.

    Radar sensors with other 77GHz sampling frequency.

  • Flexible Installation

    Flexible Installation

    The small size of the poles and elements of the yard system make the Monitoring Subsystem (SSM) particularly flexible, allowing it to be installed in a variety of locations and ensuring its applicability even in critical contexts.

    No onerous civil works are required for its installation: a simple concrete slab suitable for insulating the elements from vegetation growth is sufficient.

  • Durable over time

    Durable over time

    Radar technology does not require the support of moving parts. Unlike laser equipment that must be mounted on moving supports, radar sensors do not involve delicate and critical mechanical supports, which is why the poles and monitoring systems are more durable over time.

  • Low consumption

    Low consumption

    The entire system, which is mains-powered, involves a power consumption of between 110 and 150VA, depending on the type of configuration performed.

Support tools

Maintenance, configuration, and redesign of the system in case of PL changes can be carried out completely independently thanks to the set of intuitive and easy-to-use support tools provided under perpetual license by GCF.

Specifically, the following tools are available:

DeST (Design System Tool), an application that allows the operator to design the PAI-PL System installation, building the floor plan with all the elements present.

DCT (Diagnostic and Configuration Tool), an application used by the maintenance operator to monitor the LCP system and its subsystems.

RadarConfigurator, an application that allows the operator to set a new identifier to a radar

VCT (Verification Configuration Tool) and VAL (Validation Tool), applications that allow verification and validation of system configuration files.

Pai Pl GCF Tool

Pail-Pl: The commitment to securing the Level Crossings

Level crossings along the Italian railway networkLevel crossings along the Italian railway network

Level crossings along the Italian railway network

On the 16,800 kilometres of active lines of the Italian railway network (24,200 kilometres total) there are - 2022 data - about 4,200 level crossings, "level" intersection points between road and track.

Since the 1990s RFI, considering the system of level crossings obsolete and a source of danger mainly due to the distraction of car drivers, has worked to avoid their inclusion on newly built lines and to replace existing ones with more functional crossings, such as underpasses and overpasses.

This intervention, which has been constant over time, has gradually reduced the 7,700 level crossings present in 2000 to 5,700 in 2010, down to the current 4,200, 90 percent of which are located along "secondary lines," that is, lines with fewer than 40 rail crossings per day.

Overall, about 8,000 interferences between road and rail have been eliminated since the early 1990s with an investment of 1.7 billion euros by RFI. An average of 145 level crossings per year have been eliminated over the past 10 years.

The recent development of PAI-PL (Automatic Integrative Protection of Level Crossings) technology now offers an alternative solution that, compared to the construction of civil works such as overpasses and underpasses, has undoubted advantages in terms of design, approval and construction time, flexibility with respect to the environmental context, and undoubtedly lower costs.


Distraction killsDistraction kills

Distraction kills

Disregard for the rules, haste, distraction and wrong habitual behaviour are the main causes of level crossing accidents.

In 98 percent of cases they depend on non-compliance with the Highway Code (Art. 147). Motorists, motorcyclists, cyclists and pedestrians, often undisciplined or distracted by smartphones and electronic devices, underestimate the risks involved in crossing a level crossing, endangering their own lives, those of other road users and those traveling by train.
"Distraction Kills!" is the claim chosen by ILCAD (International Level Crossing Awareness Day) in 2021, the European Year of Railways, for an awareness campaign supported by 52 countries around the world.

The installation of new technologies that can mitigate the often deadly effects of misbehaviour should not exempt people from adopting safe behaviours near intersections with rail lines:
•    obey signs and traffic lights protecting level crossings
•    cross only when the barriers are fully up
•    stop when the bars are closing and wait for the barriers to reopen
•    do not lift, climb over, or pass under the bars when they are closed
•    observe the rules of the Highway Code (Art. 147) including, for example, the obligation to clear the crossing even by knocking down a barrier if necessary.

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LCP GCF 20191206 140446
LCP GCF 20191206 101127
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LCP GCF 20220218 130832
LCP GCF 20220218 130842
LCP GCF Granaiolo PL2

 

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Pai-Pl, the GCF radar system: Photographic Glimpses