This IDEA project demonstrated a low-cost prototype of an automated rail wheel-gauge inspection concept that had originally been developed under Transit IDEA Project 3. The rail wheel gauge uses a series of laser scanners and cameras mounted at trackside along with a series of ultrasonic sensors. These scan an entire cross-section of the wheel.
The measurement output is a digitized profile of the wheel that is processed by geometric algorithm software. A set of standard wheel measurement data compatible with existing measurements is derived from the digitized profile. Additional computations are incorporated into the algorithm to check for such critical specifications as wheel cracks, flange angle, wheel diameter, hollow tread, and so forth.
Transit operators and railroads often use time-consuming manual procedures to inspect and maintain rail wheels. Current rail wheel-inspection techniques lag behind the technological advances available for automated inspection. Existing handheld measurement instruments lead to inefficient and nonuniform inspection operations.
The product provides a complete profile of a rail wheel and inspects the wheel and flange wear. The advanced wheel inspection method is particularly attractive to rail operations where issues of wheel/rail interaction are crucial to overall performance and safety. For example, since the high-speed rail link in the Northeast corridor calls for the wheels to be inspected at the end of each run, existing wheel inspection procedures would result in an unacceptable amount of downtime.
A conference convened during the Transit IDEA project confirmed that the automatic wheelinspection system could meet rail transit requirements. The system was also field tested at the Amtrak Albany-Rensselaer Yard. IEM developed a booklet on wheel inspection stations.
Subsequently, the investigator received a contract from the New York State Energy Research and Development Authority (NYSERDA) for approximately $500,000 to expand and continue the work. Additional field tests revealed certain potential limitations of the original system, partly due to the physical design (which had necessitated the use of custom rail segments with a cut-out section) and partly due to some limitations of the hardware in real-world settings. A redesign involved added cameras and a faster and more reliable wheel detection and capture system (the detection and capture subsystem never failed to detect and trigger capture of a wheel in many months of trials). The refined system also has no special rail segments or footings for installation and a fully 3-D laser imaging-based measuring system. The current system operates at higher speeds than the prior system, has the potential to measure wheels on trains moving at normal full-transit speed, and determines all measurements by more accurate and robust means than the original design. A diagram of the current system layout is shown in Figure 1. A patent for the system was approved in October 2002 and a second patent on other aspects of the system was issued in July 2004. Additional patents are pending on the systems.
Several transit and railway companies and organizations in the U. S., including Miami-Dade County Transit, and others in countries ranging from China to Brazil have made inquiries to the investigators about obtaining these systems for commercial use. The investigator has prepared technical specs and overviews of the systems’ requirements, installation, and use for prospective customers. CSX Corporation signed a contract for the purchase and installation of one of IEM’s in-ground rail-based wheel gauge systems. The full system installation was completed in October 2006. When calibration testing is completed, IEM will be demonstrating the operating system to interested transit customers. Figure 2 show one view of the installed system at CSX Transportation’s Selkirk, New York, ‘hump yard’.
Recently, IEM as part of the consortium for Australian rail transit projects, was one of the awardees chosen to provide support and maintenance systems, including rail-based wheel inspection systems, for Sydney’s City/Rail transit network; design work on this will begin early in 2007. NTIS # PB99-113250.
