Gibran Fuentes

SitLog: A Programming Language for Service Robot Tasks

In this paper we present SitLog: a declarative situation-oriented logical language for programming situated service robot tasks. The formalism is task and domain independent, and can be used in a wide variety of settings. SitLog can also be seen as a behaviour engineering specification and interpretation formalism to support action selection by autonomous agents during the execution of complex tasks. The language combines the recursive transition network formalism, extended with functions to express dynamic and contextualized task structures, with a functional language to express control and content information. The SitLog interpreter is written in Prolog and SitLogs programs follow closely the Prolog notation, permitting the declarative specification and direct interpretation of complex applications in a modular and compact form. We discuss the structure and representation of service robot tasks in practical settings and how these can be expressed in SitLog. The present framework has been tested in the service robot Golem-II+ using the specification and programming of the typical tasks which require completion in the RoboCup@Home Competition.

Concept and Functional Structure of a Service Robot

In this paper, we present a concept of service robot and a framework for its functional specification and implementation. The present discussion is grounded in Newells system levels hierarchy which suggests organizing robotics research in three different layers, corresponding to Marrs computational, algorithmic and implementation levels, as follows: (1) the service robot proper, which is the subject of the present paper, (2) perception and action algorithms, and (3) the systems programming level. The concept of a service robot is articulated in practice through the introduction of a conceptual model for particular service robots; this consists of the specification of a set of basic robotic behaviours and a number of mechanisms for assembling such behaviours during the execution of complex tasks. The model involves an explicit representation of the task structure, allowing for deliberative reasoning and task management. The model also permits distinguishing between a robots competence and performance, along the lines of Chomskys corresponding distinction. We illustrate how this model can be realized in practice with two composition modes that we call static and dynamic; these are illustrated with the Restaurant Test and the General Purpose Service Robot Test of the RoboCup@Home competition, respectively. The present framework and methodology has been implemented in the robot Golem-II+, which is also described. The paper is concluded with an overall reflection upon the present concept of a service robot and its associated functional specifications, and the potential impact of such a conceptual model in the study, development and application of service robots in general.

Integration of the Multi-DOA Estimation Functionality to Human-Robot Interaction

Sound source localization is important in human interaction, such as in locating the origin of long-distance calls or facing other humans while in a conversation. It is of interest to apply such functionality to the core of human-robot interaction (HRI) and investigate its benefits, if any. In this paper, we propose three strategies for how to integrate the functionality of multiple directions-of-arrival (multi-DOA) estimation with a common scenario, in which the robot acts as a waiter while applying audio source localization. The proposed strategies are: a) the robot locates calls from users at a relatively long distance; b) the robot faces the user when taking the order; and c) the robot announces whether the acoustic environment is not conducive to understanding a speech command (mainly where more than one user speaks at once). It was seen that users react favourably to the functionality, and that it even has a noticeable influence on the success of the interaction.

On Indexicality, Direction of Arrival of Sound Sources, and Human-Robot Interaction

We present the use of direction of arrival (DOA) of sound sources as an index during the interaction between humans and service robots. These indices follow the notion defined by the theory of interpretation of signs by Peirce. This notion establishes a strong physical relation between signs (DOAs) and objects being signified in specific contexts. With this in mind, we have modeled the call at a distance to a robot as indexical in nature. These indices can be later interpreted as the position of the user and the user herself/himself. The relation between the call and the emitter is formalized in our framework of development of service robots based on the SitLog programming language. In particular, we create a set of behaviours based on direction of arrival information to be used in the programming of tasks for service robots. Based on these behaviours, we have implemented four tasks which heavily rely on them: following a person, taking attendance of a class, playing Marco-Polo, and acting as a waiter in a restaurant.