Searching a radiological source by a mobile robot

With the continuous expansion of international terrorist organizations, terrorists have been looking for ways to cause massive destruction, in which one of dangerous weapons is a radiological source. The explosion of radiological sources makes radioactive particles scattered over a vast area, causing radiation contamination. To avoid radiation disasters, there should be autonomous mobile robots that are equipped with radiation detectors to search any radiological sources in public places. Thus, the motivation of this paper is to find out any radiological sources in an unknown environment by an autonomous mobile robot. To estimate the accurate location of a radiological source, an artificial potential field is adopted where attractive forces are modeled by a particle filter using the model of radiation sensing model. To build up an accurate sensing model, we consider the physics of radiation and the angle of incidence of gamma ray to the radiological sensor. The simulation results show that the mobile robot is able to find the radiological source in an unknown environment.