This paper describes current progress in a project to develop robotic systems for locating underground chemical sources. There are a number of economic and humanitarian applications for this technology. Finding unexploded ordinance, land mines, and sources of leaks from pipes and tanks are some examples. Initial experiments were conducted using an ethanol chemical source buried in coarse sand. To gain an understanding of the sensory environment that would be experienced by a robot burrowing through the ground, the factors affecting transport of chemical vapour through soil were investigated. A robot search algorithrn was then developed for gathering chemical gradient inforrnation and using this to guide a robot towards the source. Experiments were performed using a chemical sensing probe positioned by a UMI RTX robot manipulator arm. The resulting system was successful in locating a source of ethanol vapour buried in sand. This paper includes details of experiments to characterise the sand used in this project, the robot search algorithm, sensor probe and results of source location trials.

This paper describes an on-going project to develop robotic systems for locating chemical sources in constrained environments. There is increasing interest in applying chemical sensing to mobile robots. Locating the source of a chemical plume is seen as an important use for a chemical sensing robot. Current research tends to concentrate on source location in open and relatively obstacle free environments. Many of the applications for this technology will be areas where airflow is constrained and deflected by obstacles such as inside buildings, mines and subway tunnels. It is this kind of situation that this project aims to address.