Development of an autonomous radiation mapping robot

The development of an autonomous robotic platform for generating radiation maps is presented. An integrated autonomous exploration algorithm, Particle Swarm Optimization algorithm, and the ability to accurately localize and map multiple radiation sources in both indoor and outdoor environments using actual sources are features of the system presented. Radiation maps provide an easy to understand view of the invisible hazards that radioactive sources pose. Previous methods of producing radiation maps either required prior knowledge of the physical dimensions of the mapping area or needed the intervention of a human operator. The method presented here improves on previous methods in that it does not require prior knowledge of the area or the intervention of an operator. The implementation consists of three main components: an exploration algorithm, a navigation system, and a source localization system. The exploration system guides the robot through the area instructing it to take radiation measurements as necessary. The navigation system provides accurate localization to maintain the accuracy of the measurements. The source localization system then uses the measurements and a radiation model to produce an estimate of the source positions and intensities. A live intensity heatmap displays preliminary information of the surroundings while the robot is exploring the area, providing useful information from the start of its operation. The intensity heatmap is updated while the robot explores, providing a more detailed view as the robot progresses through an area. The technical details of the implementation and the experimental results of the radiation mapping capabilities of a fully Autonomous Radiation Mapping Robot (ARMR) are presented in detail here. Multiple scenarios are tested, both in an outdoor and indoor environment. In the scenarios an unknown configuration of Cesium 137 sources is explored and mapped by the ARMR. The results demonstrate the effectiveness of the ARMR as a tool for mapping radiation sources in unknown environments. Such a system could be used for monitoring nuclear facilities or deployed in terrorist or radiation accident scenarios