The body is the sensor

摘要

An autonomous device called the 'Urchin' is being developed to travel through underground water pipes to listen for leaks. The Urchin consists of a hollow plastic ball just 75 mm in diameter. It must record continuously for the best part of a day. It must not get lost and must 'know' where it is sufficiently accurately to locate the leaks after post-processing data. Pressures can be high, up to 16 Bar (1586 kPa) or more and there must be no water penetration. Therefore, one requirement is to maximise the sensitivity to acoustic leak noise without any penetrations through the skin of the Urchin. At the same time, any other background noise such as that associated with pipe wall interaction must be minimised. This paper will follow our logical path through the possible ways of achieving these requirements and describes the final solution.