Background
EDAS® was originally developed in 1986 to provide a highly efficient means of data acquisition and analysis for ultrasonic inspection of nuclear power plant reactor pressure vessels and piping. The system has been upgraded multiple times since then, including a major update most recently in 2010 to EDAS-MS and minor upgrades in 2017. However, obsolescence of many hardware components used in the current design means that SwRI will soon lose our ability to reproduce another EDAS-MS. In addition, existing customers have requested new features in future systems that require a board-level redesign. Our ability to provide hardware maintenance and support for the many systems previously sold to our clients is also in serious jeopardy. Therefore, a new effort was launched to upgrade EDAS using new technology to ensure its viability and manufacturability for at least the next five years.
Approach
The EDAS system includes SwRI-proprietary hardware and software. The specialized hardware is primarily the “channel board,” which is essentially a digital ultrasonic testing (UT) instrument on a printed circuit board. An EDAS system includes multiple boards mounted in a chassis with an industry-standard bus (currently VME). The approach in this project is threefold: redesign the channel board architecture to be useable in a smaller chassis with a higher speed and a compact industry standard bus (PCI Express); combine two receiver channels onto each board for increased effective dynamic range; and improve performance to increase the maximum operation speed and lower electronic noise.
The new channel board will have two independent receiver channels for each ultrasonic transducer to allow operation at two different gain levels. This customer-requested capability will allow the customer to analyze large signals that occasionally saturate the system when the channel board is set to a normal gain level, thus avoiding rescanning areas with large indications. Conversion to the PCI Express bus will allow the EDAS system to be packaged within an industrial PC chassis that will reduce weight and costs. This conversion will also allow SwRI to transfer more data directly to the acquisition workstation that controls the system to allow more processing to be done in software on that computer rather than in hardware on the channel board. This will provide greater flexibility in modifying and reviewing data after it is acquired and will allow for future software capability enhancements.
Accomplishments
The planned architecture has been changed to allow us to make greater use of commercial off-the-shelf (COTS) hardware. Using an existing high-performance COTS analog-to-digital board with onboard analog-to-digital converters and user-programmable FPGAs will allow SwRI to provide most of the digital functions of the EDAS channel board using the COTS board capabilities. Specialized features that distinguish SwRI from commercial competitors, including high slew-rate time-controlled gain, high signal-to-noise, and real-time waveform processing, will be implemented in a separate SwRI-developed analog board and in firmware that will be developed for the COTS hardware.