RAILWAY AGE, OCTOBER 2020 ISSUE: The railroad industry has been monitoring various aspects of rail vehicle health for decades using wayside detectors. These detectors have improved the operational safety and efficiency of the North American rail network, but there are drawbacks: Wayside detectors must be strategically placed to maximize traffic coverage, for example. What if, rather than getting an “inspection” once every eventual passing of a wayside detector, it was possible to continually monitor rail vehicle health in operations?
Enter “Motes,” an abbreviation for Remote Onboard Sensors. Motes are small, self-contained sensor and communications devices affixed to a railcar component. They allow for continual, near-real-time collection and processing of data regarding critical components of a rail vehicle such as roller bearings and wheels. This data is off-boarded to the vehicle owner and may be used to prioritize maintenance, conduct trending of component health, and provide alerts to train operators regarding components that have failed, or are likely to fail, so that action can be taken.
There are two primary technical challenges associated with Motes technologies: power and communications. Motes must provide their own power in such a way to avoid an unacceptable maintenance burden on the car owner or operating railroad. In response to this requirement, suppliers have developed some rather novel approaches to overcome this problem. From the inclusion of small solar panels to energy harvesting to the use of low-power devices coupled to high-energy-density batteries (such as lithium ion), Motes suppliers continue to innovate to overcome the challenge of self-contained, long-lasting power.
Data collected by Motes devices is only of value if that data is able to be communicated to the end user in a reasonable time frame. For example, Motes that are monitoring roller bearing temperature must be able to quickly provide data indicating a bearing is in danger of overheating to either the train crew or the railroad back office so that action can be taken quickly. To accomplish this, Motes developers are exploring various methods of wireless communications. From onboard cellular to long-range wide-area networks, developers are working to provide reliable, low-power consumption and integrated communications with their products.
For several years, the Association of American Railroads (AAR) Railway Electronics Standards Committee (RESC), supported by Transportation Technology Center, Inc. (TTCI) and members of several other AAR committees, has been working to develop a set of industry standards for an Interoperable Motes System (IMS). However, in addition to the technical challenges mentioned, there are additional challenges that exist in developing standards for a Motes system that can be implemented and used across the industry.
Motes do not fit easily into the established industry method of data sharing. Wayside detector data is typically collected by the detector owner and shared at the industry level. The transmission of data from detector to industry systems is well-defined. Motes, however, offer a particular challenge as the “detector” (i.e., the Motes) may not be owned by the operating railroad. An entirely new data transmission and sharing architecture must be developed to allow car owners and Motes suppliers to share Motes data with the industry.
The Motes Technical Advisory Group has defined a new architecture that allows Motes data to be shared and consumed at the industry level. This new architecture provides flexibility in Motes deployment, allowing car owners to choose the Motes technology that best fits their business needs while also ensuring industry interoperability. Additionally, this new architecture allows Motes suppliers to continue to innovate while providing component health information that can be shared across the industry.
While Motes are not a “new” technology or concept, they do represent a new approach to data collection and sharing at the industry level. The potential for continual health monitoring of rail vehicles offers car owners and carriers alike the opportunity to enhance safety, efficiency of operations, and prioritization of maintenance. To get there, the rail industry will need to continue to encourage innovation and integration of new technologies into the current system of standards.