Decentralized multi-robot cooperation with auctioned pomdps

ABSTRACT Planning under uncertainty faces a scalability problem when considering multi-robot teams, as the information space scales exponentially with the number of robots. To address this issue, this paper proposes to decentralize multi-agent Partially Observable Markov Decision Process (POMDPs) while maintaining cooperation between robots by using POMDP policy auctions. Auctions provide a flexible way of coordinating individual policies modeled by POMDPs and have low communication requirements. Additionally, communication models in the multi-agent POMDP literature severely mismatch with real inter-robot communication. We address this issue by applying a decentralized data fusion method in order to efficiently maintain a joint belief state among the robots. The paper focuses on a cooperative tracking application, in which several robots have to jointly track a moving target of interest. The proposed ideas are illustrated in real multi-robot experiments, showcasing the flexible and robust coordination that our techniques can provide

CPS Platform Approach to Industrial Robots: State of the Practice, Potentials, Future Research Directions

Approaches, such as Cloud Robotics, Robot-as-a-Service, merged Internet of Things and robotics, and Cyber-Physical Systems (CPS) in production, show that the industrial robotics domain experiences a paradigm shift that increasingly links robots in real-life factories with virtual reality. However, despite the growing body of research to date, though insightful, the paradigm shift to CPS in industrial robotics remains an under-researched area. Findings from the present paper make several contributions to the current state of research: We provide a potentially reusable framework of analysis and apply this framework in order to reveal whether and to what extent the industrial robotics branch implements abilities and characteristics of CPS. We examine the top five industrial robot manufacturers ABB, Fanuc, Kawasaki, Kuka, and Yaskawa and identify considerable, current implementations. However, concerning one of three perspectives—the perspective on CPS as industry platform constructs, takes the industrial robotics branch only certain small steps towards CPS platforms. We discuss them and outline a set of business model patterns that can transform product innovations, enabled by abilities and characteristics of CPS, into business model innovations in the industrial robot domain. In order to enable the industry to exploit the full potential of industrial robots understood as CPS, we question the right degree of openness in the context of industry platform constructs. Our methodological approach combines conceptual with empirical research

A framework for simultaneous task allocation and planning under uncertainty

We present novel techniques for simultaneous task allocation and planning in multi-robot systems operating under uncertainty. By performing task allocation and planning simultaneously, allocations are informed by individual robot behaviour, creating more efficient team behaviour. We go beyond existing work by planning for task reallocation across the team given a model of partial task satisfaction under potential robot failures and uncertain action outcomes. We model the problem using Markov decision processes, with tasks encoded in co-safe linear temporal logic, and optimise for the expected number of tasks completed by the team. To avoid the inherent complexity of joint models, we propose an alternative model that simultaneously considers task allocation and planning, but in a sequential fashion. We then build a joint policy from the sequential policy obtained from our model, thus allowing for concurrent policy execution. Furthermore, to enable adaptation in the case of robot failures, we consider replanning from failure states and propose an approach to preemptively replan in an anytime fashion, replanning for more probable failure states first. Our method also allows us to quantify the performance of the team by providing an analysis of properties such as the expected number of completed tasks under concurrent policy execution. We implement and extensively evaluate our approach on a range of scenarios. We compare its performance to a state-of-the-art baseline in decoupled task allocation and planning: sequential single-item auctions. Our approach outperforms the baseline in terms of computation time and the number of times replanning is required on robot failure

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

Robotic Information Gathering with Reinforcement Learning assisted by Domain Knowledge: an Application to Gas Source Localization

Gas source localization tackles the problem of finding leakages of hazardous substances such as poisonous gases or radiation in the event of a disaster. In order to avoid threats for human operators, autonomous robots dispatched for localizing potential gas sources are preferable. This work investigates a Reinforcement Learning framework that allows a robotic agent to learn how to localize gas sources. We propose a solution that assists Reinforcement Learning with existing domain knowledge based on a model of the gas dispersion process. In particular, we incorporate a priori domain knowledge by designing appropriate rewards and observation inputs for the Reinforcement Learning algorithm. We show that a robot trained with our proposed method outperforms state-of-the-art gas source localization strategies, as well as robots that are trained without additional domain knowledge. Furthermore, the framework developed in this work can also be generalized to a large variety of information gathering tasks