Exploring unknown environments with RRT-based strategies

Abstract. Real mobile robots should be able to build an abstract re-presentation of the physical environment, in order to navigate and to work in such environment. We present a method for sensor-based explo-ration of unknown environments by mobile robots. This method proceeds by building a data structure called SRT (Sensor-based Random Tree). The SRT represents a roadmap of the explored area with an associated safe region, and estimates the free space as perceived by the robot during the exploration. The original work proposed in [10] presents two tech-niques: SRT-Ball and SRT-Star. In this paper, we propose an alternative strategy called SRT-Radial that deals with non-holonomic constraints us-ing two alternative planners named SRT Extensive and SRT Goal. We present experimental results to show the performance of the SRT-Radial and both derived planners