47 results for MacDonald, Bruce, Conference item

  • On internal knowledge representation for programming mobile robots by demonstration

    Abbas, T; MacDonald, Bruce (2010)

    Conference item
    The University of Auckland Library

    Intuitive learning of new behaviours is one of the important aspects of social robotics. Among various robot learning approaches, recently Programming by Demonstration (PbD) has gained significant recognition with a lot of potential. Internal representation of the knowledge is a key design choice in the learning process. Using machine learning techniques such as ANNs, HMMs and NARMAX models, simple skills can be encoded from raw sensory data. However, the abstract symbolic representations have demonstrated greater potential for learning complicated tasks but with less details and require a piece of prior knowledge as well. For a particular application, appropriate choice of the symbols is a key design issue. This paper discusses the choice of the symbols to build a PbD process for typical indoor navigation. The learning results are presented for a few tasks to demonstrate the potential of the proposed approach.

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  • Designing a Mixed Reality Framework for Enriching Interactions in Robot Simulations

    Chen, IY; MacDonald, Bruce; Wuensche, Burkhard (2010)

    Conference item
    The University of Auckland Library

    Experimentation of expensive robot systems typically requires complex simulation models and expensive hardware setups for constructing close-to-real world environments in order to obtain reliable results and draw insights to the actual operation. However, the test-development cycle is often time-consuming and resource demanding. A cost-effective solution is to conduct experiments by replacing expensive or dangerous components with simulated counterparts. Based on the concept of Mixed Reality (MR), robot simulation systems can be created to involve real and virtual entities in the simulation loop. However, seamless interaction between objects from the real and the virtual world remains a challenge. This paper presents a generic framework for constructing MR environments that facilitate interactions between objects from different dimensions of reality. In comparison to previous frameworks, we propose a new interaction scheme that describes the necessary stages for creating interactions between real and virtual objects. We demonstrate the strength of our MR framework and the proposed MR interaction scheme in the context of robot simulation. 1

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  • Designing a robotic assistant for healthcare applications

    Kuo, I-Han; Broadbent, Elizabeth; MacDonald, Bruce (2008)

    Conference item
    The University of Auckland Library

    The population of the world is ageing rapidly. By 2050, the population aged 85 and over will be three times more than it is now. This phenomenon has caused several issues in the current health service system, especially workforce shortages in the health sector and a lack of space in aged care facilities (ACFs). In the face of these issues, home-based and community-based healthcare services have been identified as necessary in many developed countries to promote ageing-inplace and independent living in order to: 1. Lower the demands on health services and hence improve the quality of the services delivered, and 2. Maintain the quality of life of the older population by enabling them to be close to their families. For the last decade, a rising interest in personal robots as part of the technical solution in decentralised health services has led to an extensive range of research and implementations of health service and personal assistant robots. This paper describes a new research project to develop an assistant robot capable of interacting with patients, taking vital signs measurements and recording the data in healthcare environments such as aged care facilities, hospitals or personal homes. Current progress includes a comprehensive literature survey on recent health service robots with a list of issues in the area and an initial human-robot interaction study. The robot is currently interfaced with a blood pressure monitor and has a 3D face which is capable of displaying a range of different emotions with lips synchronized to speech.

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  • Dynamic Reconfiguration for Robot Software

    Zheng, Yufei; Warren, Ian; MacDonald, Bruce (2006)

    Conference item
    The University of Auckland Library

    Robot applications are autonomous systems that operate in highly dynamic surroundings. Consequently, they are susceptible to changing environmental characteristics and unanticipated resource breakdowns. Furthermore, they are often required to operate for extended periods. Dynamic reconfiguration provides a powerful mechanism to enhance robot adaptability, and to allow the software to be maintained at run-time. It allows "on-the-fly" reconfiguration of robot software components to change algorithms and hardware drivers. In this paper we present an approach towards dynamic reconfiguration for robot software. The paper addresses requirements and design details for carrying out changes safely and efficiently at run-time. Further, dynamic reconfiguration is applied to two robot navigation systems with different design properties in a case study. Results show efficiency has a heavy dependence upon the choice of interaction technique between processing entities (objects). Applications built from objects that communicate asynchronously can be reconfigured more efficiently than alternative applications where inter-object communication is via explicit method invocation

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  • Evaluation of dimensional analysis in robotics

    Biggs, GM; MacDonald, Bruce (2006)

    Conference item
    The University of Auckland Library

    Robot programs typically manage a substantial amount of dimensioned data. However, existing robot programming tools do not directly support the description and manipulation of dimensioned quantities. A new data type has been proposed for managing dimensioned data in robot software. The design removes much of the hard work of using and ensuring correctness in dimensional data and allows mixing of units using dimensional analysis. An initial implementation has been created by extending the Python interpreter. This paper evaluates the proposal for dimensioned data in robotic systems, using established qualitative evaluation criteria for programming languages, based on the design and implementation, human factors, software engineering, and the application domain. In addition the paper shows that the method can be formalised, and that it is able to support coordinate systems. A set of unit tests is reported for the implementation. Together these evaluations show the proposed dimensioned data system to be implementable, self-consistent, and useful in robotics. The proposed design improves robot programming where dimensioned data is involved.

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  • Facial Expression Recognition for Human-robot Interaction - A Prototype

    wimmer, M; MacDonald, Bruce; Jayamuni, Jayamuni; Yadav, Arpit (2008)

    Conference item
    The University of Auckland Library

    To be effective in the human world robots must respond to human emotional states. This paper focuses on the recognition of the six universal human facial expressions. In the last decade there has been successful research on facial expression recognition (FER) in controlled conditions suitable for human–computer interaction [1–8]. However the human–robot scenario presents additional challenges including a lack of control over lighting conditions and over the relative poses and separation of the robot and human, the inherent mobility of robots, and stricter real time computational requirements dictated by the need for robots to respond in a timely fashion. Our approach imposes lower computational requirements by specifically adapting model-based techniques to the FER scenario. It contains adaptive skin color extraction, localization of the entire face and facial components, and specifically learned objective functions for fitting a deformable face model. Experimental evaluation reports a recognition rate of 70 % on the Cohn–Kanade facial expression database, and 67 % in a robot scenario, which compare well to other FER systems.

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  • Integration of a 3D-TOF camera into an autonomous, mobile robot system

    Hussmann, S; Schauer, D; MacDonald, Bruce (2009)

    Conference item
    The University of Auckland Library

    3D imaging systems can provide valuable information for autonomous robot navigation. Still the most significant challenge in robot navigation is to have knowledge of 3D dynamic information about the object of interest in the environment. Time-of-Flight (TOF) sensors have recently become available at reasonable prices and offer the possibility to deliver the dynamic object information required for robot navigation. In comparison to stereo vision systems and laser range scanners they combine the advantages of active sensors providing accurate distance measurements and camera-based systems recording a 2D matrix at a high frame rate. This paper focuses on the integration of a TOF sensor into an autonomous, mobile robot system. Experimental results show that the TOF sensor is more suited for robot navigation than the existing laser range system.

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  • Markerless Augmented Reality for Robots in Unprepared Environments

    Chen, Ian; MacDonald, Bruce; Wuensche, Burkhard (2008)

    Conference item
    The University of Auckland Library

    Augmented Reality (AR) can assist humans in understanding complex robot information, and improve Human and Robot Interaction (HRI). However, many restrictions are imposed by the underlying technology used and thus have lim- ited current AR systems to operate in con- trolled or modi ed robot environments. This hinders the wide spread use of AR for di er- ent robot applications. This paper presents a markerless AR system that combines recent tracking and detection techniques for AR vi- sualisation of robot task relevant information. We employ natural feature tracking techniques to compute the camera pose for accurate reg- istration of virtual objects. Automatic relocal- isation of the camera pose is achieved using a planar object detection algorithm which recov- ers from tracking failures. Experiments using a camera mounted on a mobile ground robot demonstrated accurate tracking and successful recovery of planar features in an unprepared indoor environment.

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  • Measuring and improving the accuracy of ARDev using a square grid

    Fung, Kathy; MacDonald, Bruce; Collett, Toby (2006)

    Conference item
    The University of Auckland Library

    Augmented reality (AR) systems superimpose 3D virtual objects on top of a real scene. Most applications require the AR system to maintain an accurate registration between the virtual objects and the real scene. Many AR systems use parameters obtained from the camera calibration to set up a virtual camera that models the real camera. Thus, inaccuracy in camera calibration can adversely affect the registration of an AR system. This paper proposes a calibration improvement algorithm which measures and improves accuracy of a robotics AR system that is currently used in our lab. The algorithm uses a square grid pattern as a calibration device. The vertices of the grid are defined as calibration points. The image coordinates of the calibration points are extracted using image processing technique. By comparing the difference between these image coordinates and those that are calculated using the camera parameters, the accuracy of the system can be measured. The registration error found can be used to adjust the camera parameters accordingly and thereby improves the accuracy of the system. Experiments have shown that the calibration improvement algorithm is feasible and it can be used to measure and minimise the registration error of the AR system.

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  • Real Time Simultaneous Localisation and Mapping for the Player Project

    Yang, Yung-Hsun; MacDonald, Bruce; Stol, Karl (2008)

    Conference item
    The University of Auckland Library

    This paper presents the development of a real time Simultaneous Localisation and Mapping (SLAM) application for generic robot plat- forms using Player, called the Real Time SLAM Proxy (RSP). The Extended Kalman Filter (EKF) and Multiple Particle Filter (MPF) SLAM algorithms are implemented in RSP, and experimental results are provided. RSP is in- tended for nonholonomic robots that operate in 2-D outdoor environments where landmarks can be modelled by cylindrical features and de- tected using laser range nders.

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  • Realtime Debugging for Robotics Software

    Gumbley, Luke; MacDonald, Bruce (2009)

    Conference item
    The University of Auckland Library

    Conventional software debugging constructs are insu cient for debugging robotic software due primarily to the assumption of a deter- ministic, suspendable environment. What is needed is a method to extract and report infor- mation about robotic software execution while continuing execution in the real world environ- ment. A previously theorized debugging con- struct called a tracepoint has been implemented within both a C and a Python debugger. The NetBeans IDE was modi ed to provide an ex- tensible user interface. A plugin-based visu- alisation system for rendering trace data has also been implemented. Presently, plugins for the visualisation system have been created for rendering laser and ultrasonic range nder data from the Player robot library. Benchmark tests show that although there is still signi cant room for improvement, in one typical use case the system adds less than 1% overhead.

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  • Retirement home staff and residents' preferences for healthcare robots

    Broadbent, Elizabeth; Tamagawa, Rie; Kerse, Ngaire; Knock, Brett; Patience, Anna; MacDonald, Bruce (2009)

    Conference item
    The University of Auckland Library

    As the proportion of people in the older age groups grows, demands on care providers increase. The ability of robotic technology to meet these demands is limited by a lack of acceptance by older people. This study investigates which tasks staff and residents in a retirement village would like a robot to assist with, as well as their attitudes towards robots and preferences for their appearance. Findings show that residents are more positive about robots than staff, and participants prefer a silver robot of 1.25 m height, with wheels and a screen on the body. Residents would most like the robot to assist with detecting falls, turning on and off appliances, lifting, cleaning, medication reminding, making phone calls and monitoring location. Making robots that fit these preferences may increase the acceptance of robotic assistants by older people.

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  • Robust trajectory segmentation for programming by demonstration

    Abbas, Tanveer; MacDonald, Bruce (2009)

    Conference item
    The University of Auckland Library

    A novel trajectory segmentation and modeling approach is presented. Trajectory segmentation and matching is an important step in the programming by demonstration (PbD) process to extract the user's intentions from multiple trajectories. To match multiple trajectories, the segmentation and modeling approach must be consistent and robust to disparities caused by robot dynamics and human imperfections. Several curve segmentation approaches have demonstrated substantial potential in the field of image processing and gesture recognition. They emphasize reduction of the degree of mismatch between given and model curves. However they fail to reduce mismatch between models of multiple trajectories recorded to demonstrate the same intention.We propose an M-estimator for trajectory modeling and set up a new segmentation criterion to address the issue. The proposed approach is better suited for PbD of mobile robots. The approach is evaluated for real robot trajectories.

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  • Specifying robot reactivity in procedural languages

    Biggs, Geoffrey; MacDonald, Bruce (2006)

    Conference item
    The University of Auckland Library

    A key part of programming a robotic system is specifying the responses to events that the robot may encounter. Existing methods of programming responses include event loops, reactive languages and hybrid architectures, none of which meet the specific needs of mobile robot programming. This work presents a design for new semantics for specifying reactivity in mobile robot programs, one that allows for effective specification of reactive behaviour within procedural robot programs. An initial evaluation version is implemented in Python. Events and responses are supported as program objects, and are connected together by new statements. Programmers specify connections between events and responses anywhere within the program code, so connections can easily be changed in response to changes in program and robot state

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  • Towards a flexible platform for voice accent and expression selection on a Healthcare Robot

    Igic, Aleksandar; Watson, Catherine; Teutenberg, Jonathan; Tamagawa, Rie; MacDonald, Bruce; Broadbent, Elizabeth (2009)

    Conference item
    The University of Auckland Library

    In the application of robots in healthcare, where there is a requirement to communicate vocally with non-expert users, a capacity to generate intelligible and expressive speech is needed. The Festival Speech Synthesis System is used as a framework for speech generation on our healthcare robot. Expression is added to speech by modifying mean pitch and pitch range parameters of a statistical model distributed with Festival. US and UK English diphone voices are evaluated alongside a newly made New Zealand English accented diphone voice by human judges. Results show judges can discern different accents and correctly identify the nationality of the voice.

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  • A comparison between extended kalman filtering and sequential monte carlo technique for simultaneous localisation and map-building.

    Yuen, David; MacDonald, Bruce (2002)

    Conference item
    The University of Auckland Library

    Monte Carlo Localisation has been applied to solve many di erent classes of localisation problems. In this paper, we present a possible Simultaneous Localisation and Map-building implementation using the Sequential Monte Carlo technique. Multiple particle lters are created to estimate both the robot and land- mark positions simultaneously. The proposed technique shows promising results when com- pared with those obtained with the Extended Kalman lter.

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  • Covariance Visualisations for Simultaneous Localisation and Mapping

    Kozlov, Alexei; MacDonald, Bruce; Wuensche, Burkhard (2009)

    Conference item
    The University of Auckland Library

    Simultaneous Localisation and Mapping (SLAM) is a method of environment mapping in mobile robotics. One of the most popular classes of this algorithm is the Extended- Kalman Filter (EKF) SLAM, which maps the environment by estimating similarities between currently registered scene objects and newly perceived ones. More advanced versions of this algorithm are necessary, e.g. for multiple robots or outdoor environments. However, development is di cult because of the complex interaction between the internal robot state, the perceived scene and the actual scene. New visualisation methods are hence required to enable developers to debug and evaluate EKF-SLAM algorithms. We present novel Augmented Reality based visualisation techniques which display the algorithm's progress by visualising feature and robot pose estimates, as well as correlations between fea- tures and clusters of features. The techniques allow a qualitative estimate of the algorithm's mapping compared with the ground truth and indicate the correctness and convergence properties of the SLAM system.

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  • Ruru: A spatial and interactive visual programming language for novice robot programming

    Diprose, James; MacDonald, Bruce; Hosking, John (2011)

    Conference item
    The University of Auckland Library

    Robots are useful tools for teaching novices programming as real and immediate outcomes of programs can be seen. However robot software development has unique problems making aspects of programming difficult compared with general software development. These problems include the robot platform, the robot's environment and its interaction in three-dimensional space and the fact that events occur in real time. We describe Ruru, a novel visual language that addresses these difficulties through a principled approach to its design. It also visualizes robot inputs intuitively in real time and allows the intuitive amendment of parameters. This improves its usefulness and user friendliness as a tool for teaching novices programming.

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  • A Human-Centric API for Programming Socially Interactive Robots

    Diprose, James; Plimmer, Beryl; MacDonald, Bruce; Hosking, John (2014)

    Conference item
    The University of Auckland Library

    Whilst robots are increasingly being deployed as social agents, it is still difficult to program them to interact socially. This is because current programming tools either require programmers to work at a low level or lack features needed to create certain aspects of social interaction. High level, domain specific tools with features designed specifically to meet the requirements of social interaction have the potential to ease the creation of social applications. We present a domain specific application programming interface (API) that is designed to meet the requirements of social interaction. The Cognitive Dimensions Framework was used as a design tool during the design process and the API was validated by implementing an exemplar application. The evaluation of the API showed that programmers with no robotics knowledge were positively impressed by the notation and that its organization, domain specific interfaces and object oriented nature positively affected several Cognitive Dimensions.

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  • How People Naturally Describe Robot Behaviour

    Diprose, James; Plimmer, Beryl; MacDonald, Bruce; Hosking, John (2012)

    Conference item
    The University of Auckland Library

    Existing novice robot programming systems are complex, which ironically makes them unsuitable for novices. We have analysed 19 reports of robot projects to inform development of an ontology of critical concepts that end user robot programming environments must include. This is a first step to simpler end user robot programming systems.

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