Selective Door Opening/Correct Side Door Enabling

sdo/csde

On-board train control systems play an essential role in safety within modern railway infrastructure; and to a large degree this safety has to be afforded irrespective of the age of the rolling stock and of the stations they serve. Such systems need to meet a variety of operator and regulatory requirements, and one in particular became important with the advent of powered doors.

These reduce the amount of time trains stop at stations and improve passenger safety. However, whether opened by or for passengers, the operating doors must be on the platform side of the train: a requirement that has given rise to the term Correct Side Door Enabling (CSDE). However, it is not simply a case of enabling all doors on one side of the train or the other. Many trains are longer than some of the platforms they serve, and accommodating this has given rise to the term Selective Door Operation (SDO).At a fundamental level, CSDE requires knowledge of which side of the train the platform is on and SDO requires knowledge of how many doors should be opened.

SELLA CONTROLS have been involved in Selective Door Opening systems since the early 1990s and have extensive experience in these applications.

The selection of an SDO and/or CSDE system is dependent on a number of factors such as existing technology already on board the train, route geography and commercial factors.

One of SELLA CONTROLS' solutions for conveying the knowledge for both is through the wireless transfer of data, from platform to train, using its Tracklink III® product; which was first launched in 1996 and is now in its third generation. Tracklink III® comprises two key elements for the transfer of data, namely: a passive tag for storing data relevant to a platform; and a train-mounted reader for reading that data. The ‘passive’ aspect of the tag relates to the fact that it is a beam-powered Radio Frequency ID (RFID) device. It requires no power cable or batteries.

Another solution for SDO is by the use of an onboard standalone GPS controller with or without a Tracklink III® system. This can also be offered by SELLA CONTROLS

tracklink

Typical Solutions:

Train Based ASDO and CSDE solutions using Tracklink III® Beacons and interface to Train TCMS

The system has a Tracklink III® Reader mounted in each cab vehicle per unit and communicates to the TCMS via a serial link. Tracklink III® Beacons are mounted at every platform. The Tracklink III® Beacons provide location specific information as per RIS-2795-RST to the TCMS. Based on the TCMS knowing the length of the train and the data on the length of the platform from the Tracklink III® beacon, then the TCMS can enable the correct doors at each platform.

References: Class 444, Class 450 and Class 707.

Train Based ASDO and CSDE solutions using Tracklink III® Beacons and interface to Train TCMS with GNSS

The system has a Tracklink III® Reader mounted in each unit and communicates to the TCMS via a serial link. The TCMS is used as the ASDO/CSDE controller and contains a database of the stations on the route. A GNSS geofence for each station and a network route is used so that the train identifies when it is at a particular station.  This information is used to provide the SDO functionality for most of the route. Where there are stations with different platform lengths or where there is unreliable GNSS coverage then Tracklink III® Beacons are mounted at each platform of the affected station.  At these stations the ASDO system will default to the shortest platform length unless it detects the Tracklink III®beacon, with the information from the beacon the TCMS can then release the full amount of doors for that platform. In the case of the Class 378 then all platforms are fitted with beacons to give CSDE functionality.

References: Class 378, Class 387 and Class 377. (Note: Class 377 uses Tracklink II® Beacons)

Train Based ASDO and CSDE solutions using  GNSS and Tracklink III®

The system has a EKE Trainnet® ASDO controller with GNSS and a Tracklink III® Reader mounted in each unit. The ASDO controller contains a database of the stations on the route. A  geofence for each station and a network route is used so that the train identifies when it is at a particular station.  This information is used to provide the SDO functionality for most of the route. Where there are stations with different platform lengths or where there is unreliable GNSS coverage then Tracklink III® Beacons are mounted at each platform of the affected station.  At these stations the ASDO system will default to the shortest platform length unless it detects the Tracklink III® beacon, with the information from the beacon the ASDO controller can then release the full amount of doors for that platform. The ASDO controller communicates with remote Input/output modules on each individual vehicle to release the correct doors on each vehicle.

References: Class 195, Class 331 and Class 397

Vehicle Based ASDO solution using Tracklink III® Readers and Beacons

Used on older trains where there is no TCMS or train bus that can be used. The system has a Tracklink III® Reader installed in each vehicle and a Tracklink III® beacon installed at the start of each platform on the train routes.

Any vehicle fitted with a Tracklink III® Reader that passes over a Tracklink III® beacon will have its doors enabled, any vehicle that does not pass over the Tracklink III beacon will not have its doors enabled. Interface to the door control circuits is done via outputs in the Tracklink III®Reader.

Reference: Class 458/5.

Train Based ASDO and CSDE solutions using Tracklink III® Beacons and Safety PLC

The system has a Tracklink III® Reader mounted in each cab vehicle and communicates to a safety PLC. Tracklink III® Beacons are mounted at every platform. The Tracklink III® Beacons provide location specific information. The train has to stop over the Tracklink III® Beacons within a tolerance of plus or minus 1M. If stopped in the correct place the Safety PLC enables the correct doors based on the information from the Tracklink III® beacons.

References: London Underground S-Stock

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