17 research outputs found
Efficient Multi-Robot Coverage of a Known Environment
This paper addresses the complete area coverage problem of a known
environment by multiple-robots. Complete area coverage is the problem of moving
an end-effector over all available space while avoiding existing obstacles. In
such tasks, using multiple robots can increase the efficiency of the area
coverage in terms of minimizing the operational time and increase the
robustness in the face of robot attrition. Unfortunately, the problem of
finding an optimal solution for such an area coverage problem with multiple
robots is known to be NP-complete. In this paper we present two approximation
heuristics for solving the multi-robot coverage problem. The first solution
presented is a direct extension of an efficient single robot area coverage
algorithm, based on an exact cellular decomposition. The second algorithm is a
greedy approach that divides the area into equal regions and applies an
efficient single-robot coverage algorithm to each region. We present
experimental results for two algorithms. Results indicate that our approaches
provide good coverage distribution between robots and minimize the workload per
robot, meanwhile ensuring complete coverage of the area.Comment: In proceedings of IEEE/RSJ International Conference on Intelligent
Robots and Systems (IROS), 201
Large-Scale Multi-Robot Coverage Path Planning via Local Search
We study graph-based Multi-Robot Coverage Path Planning (MCPP) that aims to
compute coverage paths for multiple robots to cover all vertices of a given 2D
grid terrain graph . Existing graph-based MCPP algorithms first compute a
tree cover on -- a forest of multiple trees that cover all vertices -- and
then employ the Spanning Tree Coverage (STC) paradigm to generate coverage
paths on the decomposed graph of the terrain graph by circumnavigating
the edges of the computed trees, aiming to optimize the makespan (i.e., the
maximum coverage path cost among all robots). In this paper, we take a
different approach by exploring how to systematically search for good coverage
paths directly on . We introduce a new algorithmic framework, called
LS-MCPP, which leverages a local search to operate directly on . We propose
a novel standalone paradigm, Extended-STC (ESTC), that extends STC to achieve
complete coverage for MCPP on any decomposed graphs, even those resulting from
incomplete terrain graphs. Furthermore, we demonstrate how to integrate ESTC
with three novel types of neighborhood operators into our framework to
effectively guide its search process. Our extensive experiments demonstrate the
effectiveness of LS-MCPP, consistently improving the initial solution returned
by two state-of-the-art baseline algorithms that compute suboptimal tree covers
on , with a notable reduction in makespan by up to 35.7\% and 30.3\%,
respectively. Moreover, LS-MCPP consistently matches or surpasses the results
of optimal tree cover computation, achieving these outcomes with orders of
magnitude faster runtime, thereby showcasing its significant benefits for
large-scale real-world coverage tasks.Comment: Accepted to AAAI 202
Swarm robotics in wireless distributed protocol design for coordinating robots involved in cooperative tasks
The mine detection in an unexplored area is an optimization problem where multiple mines, randomly distributed throughout an area, need to be discovered and disarmed in a minimum amount of time. We propose a strategy to explore an unknown area, using a stigmergy approach based on ants behavior, and a novel swarm based protocol to recruit and coordinate robots for disarming the mines cooperatively. Simulation tests are presented to show the effectiveness of our proposed Ant-based Task Robot Coordination (ATRC) with only the exploration task and with both exploration and recruiting strategies. Multiple minimization objectives have been considered: the robots' recruiting time and the overall area exploration time. We discuss, through simulation, different cases under different network and field conditions, performed by the robots. The results have shown that the proposed decentralized approaches enable the swarm of robots to perform cooperative tasks intelligently without any central control
DARP: Divide Areas Algorithm for Optimal Multi-Robot Coverage Path Planning
This paper deals with the path planning problem of a team of mobile robots, in order to cover an area of interest, with prior-defined obstacles. For the single robot case, also known as single robot coverage path planning (CPP), an (n) optimal methodology has already been proposed and evaluated in the literature, where n is the grid size. The majority of existing algorithms for the multi-robot case (mCPP), utilize the aforementioned algorithm. Due to the complexity, however, of the mCPP, the best the existing mCPP algorithms can perform is at most 16 times the optimal solution, in terms of time needed for the robot team to accomplish the coverage task, while the time required for calculating the solution is polynomial. In the present paper, we propose a new algorithm which converges to the optimal solution, at least in cases where one exists. The proposed technique transforms the original integer programming problem (mCPP) into several single-robot problems (CPP), the solutions of which constitute the optimal mCPP solution, alleviating the original mCPP explosive combinatorial complexity. Although it is not possible to analytically derive bounds regarding the complexity of the proposed algorithm, extensive numerical analysis indicates that the complexity is bounded by polynomial curves for practically sized inputs. In the heart of the proposed approach lies the DARP algorithm, which divides the terrain into a number of equal areas each corresponding to a specific robot, so as to guarantee complete coverage, non-backtracking solution, minimum coverage path, while at the same time does not need any preparatory stage (video demonstration and standalone application are available on-line http://tinyurl.com/DARP-app)
A Survey and Analysis of Multi-Robot Coordination
International audienceIn the field of mobile robotics, the study of multi-robot systems (MRSs) has grown significantly in size and importance in recent years. Having made great progress in the development of the basic problems concerning single-robot control, many researchers shifted their focus to the study of multi-robot coordination. This paper presents a systematic survey and analysis of the existing literature on coordination, especially in multiple mobile robot systems (MMRSs). A series of related problems have been reviewed, which include a communication mechanism, a planning strategy and a decision-making structure. A brief conclusion and further research perspectives are given at the end of the paper