Multi-Robot Fire Searching in Unknown Environment

Abstract

Abstract. Exploration of an unknown environment is a fundamental concern in mobile robotics. This paper presents an approach for cooperative multi-robot exploration, fire searching and mapping in an unknown environment. The proposed approach aims to minimize the overall exploration time, making it possible to locate fire sources in an efficient way. In order to achieve this goal, the robots cooperate in order to individually and simultaneously, explore different areas of the environment while they identify fire sources. The proposed approach employs a decentralized frontier based exploration method which evaluates the cost/gain ratio to navigate to target way-points. The target way-points are obtained by an A* search variant algorithm. The potential field method is used to control the robots' motion while avoiding obstacles. When a robot detects a fire, it estimates the flame's position by triangulation. The communication between the robots is done in a decentralized control manner where they share the necessary data to generate a map of the environment and to perform cooperative actions in a behavioral decision making way. This paper presents simulated and experimental results of the proposed exploration and fire search method and concludes with a discussion of the obtained results and future improvements.

Multi-robot olfactory search in structured environments

“…If the robots know their relative locations and share a map of the explored area, then effective coordination can be achieved through guiding the robots into different, non-overlapping areas of the environment. In other words, effective coordination can be achieved by extracting exploration frontiers from the partial maps and assigning robots to frontiers based on a global measure of performance [14,18]. Frontier based exploration is a simple approach for decentralized multiple robot task allocation (Fig.…”

“…Most of the related works in this area (namely [18] and [14]) try to explore the environment with minimal excess effort in the minimum possible time, however, the main goal of this project is olfactory search rather than exploration. The exploration must be done in such a way that the group of robots automatically intends to look for the odor sources in the environment.…”

“…This is a difficult problem to solve when the robots do not have a common reference frame or physical global positioning system [20]. Most of the existing approaches to coordinate multi-robot mapping assume that all agents know their locations in a shared (partial) map of the environment [13,14,18]. Having a physical general positioning system is an undesired constraint in unknown areas where there is no previous knowledge about the environment.…”

“…In our previous studies [13,18], techniques for multiple robots that intended to explore an unknown environment and generate its topological map were presented. In those studies the robots explore the whole environment but the current research tries to search the environment based on the odor concentration that is reported in each frontier while at the end the whole environment will be explored.…”

Multi-robot Topological Exploration Using Olfactory Cues

“…The authors have been working on the problem of finding odor and fire sources with robots in previous studies [1,2,3,4,5]. This current project tries to address the problem of odor source searching in unknown environments by complementing it with the environment exploration and mapping.…”