RTC Magazine

Today’s railroads work harder than ever. A growing economy and ever increasing world trade has rail traffic levels at all time highs, straining existing rail system operations beyond their capacities. Operators can still lose track of the whereabouts of a particular locomotive or train car. There is no system to enable operators to effectively monitor a diverse fleet, with forty-year-old locomotives rolling along side sleek, new high-speed bullet trains.

Railroad companies want to take advantage of the tremendous revenue opportunities that come with a strong demand for their services. To do so, they must find more efficient, reliable, safe and secure ways to stay on track. They need technologies that enable them to carefully and continuously monitor their fleet utilization, manage fuel and implement predictive maintenance to keep trains up and running.

A railroad’s primary obstacle to managing a geographically and technologically diverse mobile fleet is the lack of a common data interface. Electronic systems on board locomotives vary widely depending on their purpose, manufacturer, model and age. Each system has a unique physical interface and data protocol. Even though the information collected is similar, until now there has been no universal data format. Furthermore, there is no universal standard for data transfer using wireless network communications to collect data from onboard systems.

This is changing with the development of new products and services that provide remote monitoring information, with real-time reporting and analysis, across diverse fleets. Wi-Tronix, a company that provides technology to wirelessly monitor high-value mobile assets, understood the challenges of having diverse data formats. Focusing on mobile assets such as locomotives, haul trucks, industrial equipment and marine vessels, they made it their business to bridge the gap between the various data formats used by different manufacturers of onboard monitoring equipment. Wi-Tronix created a universal interface platform that renders system data from a wide array of onboard electronic devices into a common, standards-based data format. It is now possible to manage an entire fleet as one cohesive network blending new and old locomotives and equipment from different manufacturers.

A ruggedized computing platform, called the Wi-PU (Wireless Processing Unit) is installed on each locomotive, and taps into each onboard system. The Wi-PU includes Ethernet, USB, serial and discrete I/O connectivity in order to connect with external systems such as engine controllers, data recorders, fuel monitors, digital video recorders, remote control systems and analog sensors. Each Wi-PU is equipped with state-of-the-art wireless technologies and an embedded Global Positioning System (GPS) module, which includes Differential GPS (DGPS) correction and can locate a mobile asset to within 3 meters.

To exchange data and control information between the Wi-PU on board a mobile asset and the remote tracking applications, a robust, real-time messaging architecture was needed that would serve as a universal foundation for current and future applications. A commercial-off-the-shelf, industry standard solution from Real-Time Innovations (RTI) enabled getting to market within five months.

RTI provides high-performance messaging middleware based on the Object Management Group’s (OMG) Data Distribution Service standard. The DDS implements a publish-subscribe model for sending and receiving data, events and commands among the nodes. Applications that produce information create topics, for example “Temperature” or “Location,” and publish samples associated with that topic. The Data Distribution Service (DDS) delivers each sample to all subscribers that declare an interest in that topic. The DDS publish-subscribe model virtually eliminates complex network programming for distributed applications. It also supports mechanisms that go beyond the basic publish-subscribe model including support for a variety of hardware and operating systems.

The key benefit is that applications that use DDS for their communications are entirely decoupled. Very little design time has to be spent on how to handle their mutual interactions. In particular, the applications never need information about the other participating applications, including their existence or locations. DDS automatically handles all aspects of message delivery, without requiring any intervention from the user applications, including determining who should receive the messages; where recipients are located; and what happens if messages cannot be delivered. Thus, new nodes can be added at anytime and will be able to send and receive messages from existing nodes.