1,720,970 research outputs found
Keep the planner in the loop: parallel planning and execution using Large Language Models
No full textTask planning is a popular approach for autonomous agents due to its understandability, predictability, and ease of deployment. However, it is difficult to scale in real-world, human-robot cooperation scenarios due to the poor performance scaling in complex planning domains and when frequent re-planning is needed. Longer planning times can hinder the robot's efficiency and adversely affect the interaction's fluency. Our objective in this PhD project is to develop novel methods to address this issue and favor keeping task planning in the execution loop as much as possible. First, we explore the use of traditional planning techniques, and in particular the use of macros, to optimize total planning and execution time. Macros are known to reduce planning time, but at the cost of plan optimality and thus execution time. We provide evidence that by selecting an appropriate level of macro abstraction and by implementing ad-hoc grounding for said macros, it is possible to reduce average planning time by 85% with little impact on execution time. Then, we proceed to explore more innovative approaches based on the latest advancement in generative AI. In particular, we propose a method, Teriyaki, to bridge the gap between symbolic task planning and machine learning methods, by training Large Language Models (LLMs), namely GPT-3, into a neurosymbolic planner compatible with the Planning Domain Definition Language (PDDL). Potential benefits include better scalability, as LLMs' response time scales with the combined length of the input and the output regardless of the symbols involved; and the ability to generate a plan action-by-action, which in turn enables simultaneous planning and execution, reducing wait times. In the past year, significant effort has been devoted by the AI community to evaluate the overall cognitive abilities of LLMs, but success rate has been limited. Instead, we focus on providing a success rate comparable to traditional planners in specific planning domains, while improving other real-world metrics. Preliminary results in two domains selected from those developed in the first part of this project, show that our method can: (i) solve 95.5% of problems in a test data set of 1000 samples, a result comparable with that of the baseline heuristic-search planner; (ii) produce plans up to 13.5% shorter than a traditional planner; (iii) reduce average waiting times for a plan by 61,4% and its standard deviation by 96.6% through parallel planning and execution
An ontology-based hybrid architecture for planning and robust execution in tabletop scenarios
No full textKR&R approaches for robot manipulation tasks with articulated objects
No full textIn this paper we present two approaches for solving robot manipulation tasks with articulated objects by using knowledge representation and reasoning languages and tools. Such languages and tools are used both for representing initial and final configurations from an ontology description and for planning the robot (manipulation) actions. In the first approach, standard PDDL language and solvers are used to plan those actions, and DL solvers for ontology consistency checking. In the second (ongoing) approach, ASP is employed as a unifying framework for both ontology checking and planning
Automated Planning Encodings for the Manipulation of Articulated Objects in 3D with Gravity
Full text linkThe manipulation of articulated objects plays an important role in real-world robot tasks, both in home and industrial environments. A lot of attention has been devoted to the development of ad hoc approaches and algorithms for generating the sequence of movements the robot has to perform in order to manipulate the object. Such approaches can hardly generalise on different settings, and are usually focused on 2D manipulations.In this paper we introduce a set of PDDL+ formulations for performing automated manipulation of articulated objects in a three-dimensional workspace by a dual-arm robot. Presented formulations differ in terms of how gravity is modelled, considering different trade-offs between modelling accuracy and planning performance, and between human-readability and parsability by planners. Our experimental analysis compares the formulations on a range of domain-independent planners, that aim at generating plans for allowing a dual-arm robot to manipulate articulated objects of different sizes. Validation is performed in simulation on a Baxter robot
Long-Term Area Coverage and Radio Relay Positioning Using Swarms of UAVs
No full textUnmanned Aerial Vehicles (UAVs) are becoming increasingly useful for tasks that require the acquisition of data over large areas. Online coverage algorithms obviously pose a greater challenge to ensure efficient operations with multiple UAVs compared to offline ones. Optimal relay positioning is a widely explored problem in the telecommunication field, where it is used to place antennas in a given area to provide robust wireless connection. The chapter presents the experiments used to assess the performance of the simultaneous coverage and relay-positioning algorithm and the related architecture. It proposes a novel approach to improve the performance of a UAVs swarm tasked to cover a given area in difficult contexts such as natural disasters. Future developments will deal with further increasing the robustness of the proposed architecture by exploring in detail the best strategies to adopt when multiple UAVs are busy with secondary tasks or to avoid the chain to be interrupted
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An ASP-Based Framework for the Manipulation of Articulated Objects using Dual-Arm Robots
Full text linkThe manipulation of articulated objects is of primary importance in robotics, and is one of the most complex robotics tasks. Traditionally, this problem has been tackled by developing ad-hoc approaches, that lack of flexibility and portability. In this paper we present a framework based on Answer Set Programming (ASP) for the automated manipulation of articulated objects in a robot architecture. In particular, ASP is employed for representing the configuration of the articulated object, for checking the consistency of the knowledge base, as well as for generating the sequence of manipulation actions. The framework is validated both in simulation and on the Baxter dual-arm manipulator, showing the applicability of the ASP methodology in this complex application scenario
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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