CONTINUOUS STRUCTURAL HEALTH MONITORING GUIDED WAVE PPM SYSTEM USING STEEL PIPES AS COMMUNICATION CHANNEL FOR FLOOD DETECTION IN STEEL OFFSHORE OILRIGS

An automatic guided wave pulse position modulation system, using steel tubes as communication channel, for detecting flooding in the hollow sub‐sea structures of offshore oilrigs is presented. The system employs two smart PZT‐based sensors and modulators and a demodulator based on a PZT transducer, a DSP and a microcontroller. Experiments performed in a tubular steel heliport structure and the base of a deck of an oilrig under construction, have successfully distinguished automatically guided wave encoded information.