Cellular positioner eases rail commute

Staff -- Control Engineering, 9/1/1998

Coquitlam, British Columbia, Canada--Rail commuters to downtown Vancouver now have a much better chance of getting to work or making connections on time thanks to a new cellular positioning system coordinating their trains. The public commuter rail service, West Coast Express (WCE) Ltd., runs five westbound trains in the morning and five evening returns between Mission, B.C., and Vancouver. Each trip carries more than 1,000 commuters about 60 km.

Designed by AVL International Inc., the system uses customized, off-the-shelf hardware and software running on a standard Pentium desktop computer to display a conventional rail synoptic map and steet map view of the position of each train in real time throughout their routes. AVL's system also gives the WCE dispatch center schedule adherence data on each train, which can then be used to coordinate passenger transfers to other mass transit carriers at each of the eight stations along its route. Trip logs of each run are also created for performance auditing and to administer contractual service obligations of the line, which is owned by CP Rail.

In conjunction with the new system, each train was fitted with a Sierra Wireless MP200/Global Positioning System (GPS), Cellular Digital Packet Data (CDPD) modem with an internal Trimble GPS receiver. Each unit is programmed to automatically report its train's identification, position, velocity, and direction of travel every 100 m via a wireless communication link. To accomplish these tasks, WCE selected CDPD, which is a digital, wireless transmission system that uses an existing cellular telephone network.

Information the system provides includes location within 30 m and estimating arrival times at the next station to within 30 sec. "Having a true picture of schedule adherence also gives WCE dispatch warnings of late or early arrivals and any unexpected stops en route," says Doug Stead, AVL's president. "Positioning information will also come in handy in the event of an emergency by letting response teams know exactly where the train is and the best route to get to it." Pinpointing prior to this system meant finding the train "anywhere along a section of track as long as 10 km."

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