Khushaba, RN, Kodagoda, S, Lal, S & Dissanayake, G 2011, 'Driver Drowsiness Classification Using Fuzzy Wavelet-Packet-Based Feature-Extraction Algorithm', IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, vol. 58, no. 1, pp. 121-131.
View/Download from: Publisher's site
View description>>
Driver drowsiness and loss of vigilance are a major cause of road accidents. Monitoring physiological signals while driving provides the possibility of detecting and warning of drowsiness and fatigue. The aim of this paper is to maximize the amount of drowsiness-related information extracted from a set of electroencephalogram (EEG), electrooculogram (EOG), and electrocardiogram (ECG) signals during a simulation driving test. Specifically, we develop an efficient fuzzy mutual-information (MI)- based wavelet packet transform (FMIWPT) feature-extraction method for classifying the driver drowsiness state into one of predefined drowsiness levels. The proposed method estimates the required MI using a novel approach based on fuzzy memberships providing an accurate-information content-estimation measure. The quality of the extracted features was assessed on datasets collected from 31 drivers on a simulation test. The experimental results proved the significance of FMIWPT in extracting features that highly correlate with the different drowsiness levels achieving a classification accuracy of 95%-97% on an average across all subjects. © 2011 IEEE.
Mahony, R, Euston, M, Kim, J, Coote, P & Hamel, T 2011, 'A non-linear observer for attitude estimation of a fixed-wing unmanned aerial vehicle without GPS measurements', Transactions of the Institute of Measurement and Control, vol. 33, no. 6, pp. 699-717.
View/Download from: Publisher's site
View description>>
In this paper we propose a simple non-linear observer for attitude estimation based only on output from a typical inertial measurement unit (IMU) and dynamic pressure sensor embarked on a low-cost unmanned aerial vehicle. In particular, we aim to provide a good quality attitude estimate in the absence of global positioning system (GPS) ground truth and with potential low-frequency bias and high-frequency noise in the IMU sensor measurements. In addition, the case where the IMU only provides gyrometer and accelerometer outputs is considered; that is, there is no magnetometer output or it cannot be used due to local magnetic disturbances such as are common on a vehicle with electric motors. The proposed observer uses a simple centripetal force model (based on gyrometer and dynamic pressure measurements), augmented by a first-order dynamic model for angle of attack, to estimate non-inertial components of the acceleration. This estimate is used to correct the accelerometer output to provide a low-frequency estimate of the gravitational direction. This inertial direction, along with the gyrometer output, is then used to drive a fully non-linear attitude observer posed on the orthogonal group of rotation matrices SO(3). The observer is augmented with an integral state that ensures compensation of gyrometer bias. The resulting observer is simple to implement and fully non-linear. Experimental results are provided on a real-world data set and the performance of the filter is evaluated against the output from a full GPS/inertial navigation system (INS) that was available for the data set.
Meng, X, Wang, S, Qiu, J, Zhang, Q, Zhu, JG, Guo, Y & Liu, D 2011, 'Robust Multilevel Optimization of PMSM Using Design for Six Sigma', IEEE Transactions on Magnetics, vol. 47, no. 10, pp. 3248-3251.
View/Download from: Publisher's site
View description>>
In this paper, a robust optimization method based on design for six sigma (DFSS) is combined to the optimization of a surface mounted permanent synchronous machine (PMSM) by using multilevel genetic algorithm (MLGA). First, MLGA and DFSS are introduced in the robust optimization. Second, by taking into account the tolerances of the motor products, important input parameters could be varied with six sigma distribution and Monte Carlo simulation (MCS) method is used to reduce the calculation cost. Third, to verify the new algorithm, the presented algorithm is applied to the optimization of a PMSM. The results compared with those of traditional GA and MLGA and the discussion of the robust optimization combined with MLGA are presented. © 2011 IEEE.
Paul, G, Webb, S, Liu, D & Dissanayake, G 2011, 'Autonomous robot manipulator-based exploration and mapping system for bridge maintenance', ROBOTICS AND AUTONOMOUS SYSTEMS, vol. 59, no. 7-8, pp. 543-554.
View/Download from: Publisher's site
View description>>
This paper presents a system for Autonomous eXploration to Build A Map (AXBAM) of an unknown, 3D complex steel bridge structure using a 6 degree-of-freedom anthropomorphic robot manipulator instrumented with a laser range scanner. The proposed algorithm considers the trade-off between the predicted environment information gain available from a sensing viewpoint and the manipulator joint angle changes required to position a sensor at that viewpoint, and then obtains collision-free paths through safe, previously explored regions. Information gathered from multiple viewpoints is fused to achieve a detailed 3D map. Experimental results show that the AXBAM system explores and builds quality maps of complex unknown regions in a consistent and timely manner. © 2011 Elsevier B.V. All rights reserved.
Vidal-Calleja, TA, Berger, C, Solà, J & Lacroix, S 2011, 'Large scale multiple robot visual mapping with heterogeneous landmarks in semi-structured terrain', Robotics and Autonomous Systems, vol. 59, no. 9, pp. 654-674.
View/Download from: Publisher's site
View description>>
This paper addresses the cooperative localization and visual mapping problem with multiple heterogeneous robots. The approach is designed to deal with the challenging large semi-structured outdoors environments in which aerial/ground ensembles are to evolve. We propose the use of heterogeneous visual landmarks, points and line segments, to achieve effective cooperation in such environments. A large-scale SLAM algorithm is generalized to handle multiple robots, in which a global graph maintains the relative relationships between a series of local sub-maps built by the different robots. The key issue when dealing with multiple robots is to find the link between them, and to integrate these relations to maintain the overall geometric consistency; the events that introduce these links on the global graph are described in detail. Monocular cameras are considered as the primary extereoceptive sensor. In order to achieve the undelayed initialization required by the bearing-only observations, the well-known inverse-depth parametrization is adopted to estimate 3D points. Similarly, to estimate 3D line segments, we present a novel parametrization based on anchored Plcker coordinates, to which extensible endpoints are added. Extensive simulations show the proposed developments, and the overall approach is illustrated using real-data taken with a helicopter and a ground rover. © 2011 Elsevier B.V. All rights reserved.
Yuan, S, Skinner, BT, Huang, S, Liu, DK, Dissanayake, G, Lau, H & Pagac, D 2011, 'A job grouping approach for planning container transfers at automated seaport container terminals', ADVANCED ENGINEERING INFORMATICS, vol. 25, no. 3, pp. 413-426.
View/Download from: Publisher's site
View description>>
This paper proposes a practical job grouping approach, which aims to enhance the time related performance metrics of container transfers in the Patrick AutoStrad container terminal, located in Brisbane, Australia. It first formulates a mathematical model of the automated container transfers in a relatively complex environment. Apart from the consideration on collision avoidance of a fleet of large vehicles in a confined area, it also deals with many other difficult practical challenges such as the presence of multiple levels of container stacking and sequencing, variable container orientations, and vehicular dynamics that require finite acceleration and deceleration times. The proposed job grouping approach aims to improve the makespan of the schedule for yard jobs, while reducing straddle carrier waiting time by grouping jobs using a guiding function. The performance of the current sequential job allocation method and the proposed job grouping approach are evaluated and compared statistically using a pooled t-test for 30 randomly generated yard configurations. The experimental results show that the job grouping approach can effectively improve the schedule makespan and reduce the total straddle carrier waiting time. © 2011 Elsevier Ltd. All rights reserved.
Abeywardena, D, Kodagoda, S, Munasinghe, R & Dissanayake, G 1970, 'A virtual odometer for a Quadrotor Micro Aerial Vehicle', Proceedings of the 2011 Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Australian Robotics and Automation Association, Monash University, Melbourne, pp. 1-8.
View description>>
This paper describes the synthesis and evaluation of a 'virtual odometer' for a Quadrotor Micro Aerial Vehicle. Availability of a velocity estimate has the potential to enhance the accuracy of mapping, estimation and control algorithms used with quadrotors, increasing the effectiveness of their applications. As a result of the unique dynamic characteristics of the quadrotor, a dual axis accelerometer mounted parallel to the propeller plane provides measurements that are directly proportional to vehicle velocities in that plane. Exploiting this insight, we encapsulate quadrotor dynamic equations which relate acceleration, attitude and the aerodynamic propeller drag in an extended Kalman filter framework for the purpose of state estimation. The result is a drift free estimation of lateral and longitudinal components of translational velocity and roll and pitch components of attitude of the quadrotor. Real world data sets gathered from two different quadrotor platforms, together with ground truth data from a Vicon system, are used to evaluate the effectiveness of the proposed algorithm and demonstrate that drift free estimates for the velocity and attitude can be obtained.
Ahmad, A, Huang, S, Wang, JJ & Dissanayake, G 1970, 'A new state vector for range-only SLAM', 2011 Chinese Control and Decision Conference (CCDC), 2011 23rd Chinese Control and Decision Conference (CCDC), IEEE, Mianyang, Sichuan, China, pp. 3404-3409.
View/Download from: Publisher's site
View description>>
This paper considers the simultaneous localization and mapping (SLAM) problem where the range-only sensor is used. Landmark initialization is a critical issue in range-only SLAM due to the lack of bearing information from the robot to the landmarks. A new state vector is proposed to be used in solving the range-only SLAM. In the new state vector, the landmark position is represented in different ways under different situations. This new representation avoids the need of multiple hypotheses on the landmark positions implemented in most of the existing range-only SLAM algorithms. Simulation and experimental results demonstrate the effectiveness of the new range-only SLAM algorithm using the new state vector within the least squares framework. © 2011 IEEE.
Binghuang Cai, Shoudong Huang, Dikai Liu, Shuai Yuan, Dissanayake, G, Lau, H & Pagac, D 1970, 'Optimisation model and exact algorithm for autonomous straddle carrier scheduling at automated container terminals', 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011), IEEE, pp. 3686-3693.
View/Download from: Publisher's site
Brunner, C, Peynot, T & Vidal-Calleja, T 1970, 'Combining multiple sensor modalities for a localisation robust to smoke', 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011), IEEE.
View/Download from: Publisher's site
Brunner, C, Peynot, T & Vidal-Calleja, T 1970, 'Combining multiple sensor modalities for a localisation robust to smoke', 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011), IEEE, San Francisco, CA, pp. 2489-2496.
View/Download from: Publisher's site
View description>>
This paper proposes an approach to obtain a localisation that is robust to smoke by exploiting multiple sensing modalities: visual and infrared (IR) cameras. This localisation is based on a state-of-the-art visual SLAM algorithm. First, we show that a reasonably accurate localisation can be obtained in the presence of smoke by using only an IR camera, a sensor that is hardly affected by smoke, contrary to a visual camera (operating in the visible spectrum). Second, we demonstrate that improved results can be obtained by combining the information from the two sensor modalities (visual and IR cameras). Third, we show that by detecting the impact of smoke on the visual images using a data quality metric, we can anticipate and mitigate the degradation in performance of the localisation by discarding the most affected data. The experimental validation presents multiple trajectories estimated by the various methods considered, all thoroughly compared to an accurate dGPS/INS reference. © 2011 IEEE.
Cai, B, Huang, S, Liu, D, Yuan, S, Dissanayake, G, Lau, H, Pagac, D & IEEE 1970, 'Optimisation Model and Exact Algorithm for Autonomous Straddle Carrier Scheduling at Automated Container Terminals', 2011 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Francisco, California, USA, pp. 3686-3693.
View/Download from: Publisher's site
View description>>
In this paper, an optimisation model based on Pickup and Delivery Problem with Time Windows (PDPTW), and an exact algorithm based on Branch-and-Bound with Column Generation (BBCG), are presented for Autonomous Straddle Carriers Scheduling (ASCS) problem at automated container terminals. The ASCS problem is firstly modeled into a PDPTW, which is formulated as a Binary Integer Programming (BIP) and then solved by Column Generation (CG) in the Branch-and-Bound (BB) framework. The BBCG algorithm is also compared to another two exact algorithms [i.e., Binary integer Programming with Dynamic Programming (BPDP) and Exhaustive Search with Permutation and Combination (ESPC)] for the ASCS problem solving. Based on the map of an actual automated container terminal, simulation results and discussions are presented to demonstrate the effectiveness and efficiency of the presented model and algorithm for autonomous vehicle scheduling. © 2011 IEEE.
Carmichael, MG & Dikai Liu 1970, 'Towards using musculoskeletal models for intelligent control of physically assistive robots', 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2011 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE, Boston, MA, pp. 8162-8165.
View/Download from: Publisher's site
View description>>
With the increasing number of robots being developed to physically assist humans in tasks such as rehabilitation and assistive living, more intelligent and personalized control systems are desired. In this paper we propose the use of a musculoskeletal model to estimate the strength of the user, from which information can be utilized to improve control schemes in which robots physically assist humans. An optimization model is developed utilizing a musculoskeletal model to estimate human strength in a specified dynamic state. Results of this optimization as well as methods of using it to observe muscle-based weaknesses in task space are presented. Lastly potential methods and problems in incorporating this model into a robot control system are discussed. © 2011 IEEE.
Chotiprayanaku, P, Liu, D & Dissanayake, G 1970, 'An Extended Hand Movement Model for Haptic-Based Remote Operation of Infrastructure Maintenance Robots', Proceedings of the International Symposium on Automation and Robotics in Construction (IAARC), 28th International Symposium on Automation and Robotics in Construction, International Association for Automation and Robotics in Construction (IAARC), Seoul, Korea, pp. 1196-1202.
View/Download from: Publisher's site
Chotiprayanakul, P, Liu, D & Paul, G 1970, 'Effect of View Distance and Movement Scale on Haptic-Based Teleoperation of Industrial Robots in Complex Environments', Proceedings of the 28th International Symposium on Automation and Robotics in Construction (ISARC 2011), International Association for Automation and Robotics in Construction (IAARC), Seoul, Korea, pp. 1019-1024.
View/Download from: Publisher's site
Chotiprayanakul, P, Liu, D & Paul, G 1970, 'Effect of View Distance and Movement Scale on Haptic-Based Teleoperation of Industrial Robots in Complex Environments', Proceedings of the International Symposium on Automation and Robotics in Construction (IAARC), 28th International Symposium on Automation and Robotics in Construction, International Association for Automation and Robotics in Construction (IAARC), Seoul, Korea, pp. 1019-1024.
View/Download from: Publisher's site
View description>>
This paper presents the study on the effect of view distance and movement scale on performance of haptic based teleoperation of a sandblasting robot in complex steel bridge maintenance environments. The operational performance, measured by the Index of Performance (IP), is defined based on the speed and the control accuracy of the manipulator. View distance (i.e. the distance between a display space and an object movement space) and movement scale between hand movement and manipulator movement, which are normally selected empirically, have significant effect the performance. In this paper, an experimental approach is used for determining view distance and movement scale. The sandblasting robotic system is used as an example industrial application in the experiments. Results of the experiments show a range of the view distance and the movement scale that can improve the performance of haptic-based teleoperation of industrial robots in complex environments.
Dissanayake, G, Huang, S, Wang, Z & Ranasinghe, R 1970, 'A review of recent developments in Simultaneous Localization and Mapping', 2011 6th International Conference on Industrial and Information Systems, 2011 IEEE 6th International Conference on Industrial and Information Systems (ICIIS), IEEE, Sri Lanka, pp. 477-482.
View/Download from: Publisher's site
View description>>
Simultaneous Localization and Mapping (SLAM) problem has been an active area of research in robotics for more than a decade. Many fundamental and practical aspects of SLAM have been addressed and some impressive practical solutions have been demonstrated. The aim of this paper is to provide a review of the current state of the research on feature based SLAM, in particular to examine the current understanding of the fundamental properties of the SLAM problem and associated issues with the view to consolidate recent achievements. © 2011 IEEE.
Gan, SK & Sukkarieh, S 1970, 'Multi-UAV Target Search using Explicit Decentralized Gradient-Based Negotiation', 2011 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA), IEEE International Conference on Robotics and Automation (ICRA), IEEE, PEOPLES R CHINA, Shanghai.
Herath, DC, Chapman, T, Tomkins, A, Elliott, L, David, M, Cooper, A, Burnham, D & Kodagoda, S 1970, 'A study on wearable robotics — Comfort is in the context', 2011 IEEE International Conference on Robotics and Biomimetics, 2011 IEEE International Conference on Robotics and Biomimetics (ROBIO), IEEE, Phuket, Thailand, pp. 2969-2974.
View/Download from: Publisher's site
View description>>
WITU (Wearable Indoor Tracking Unit) is a wearable robotic device that aids indoor navigation by building maps and localizing the user within them. Applications of such a device include search and rescue, travel aid in large and complex buildings, museum guides among others where external localization information such as from a GPS is not available. However, WITU relies on human intelligence both to maintain long term consistency of its location estimates and to efficiently manage its limited memory and processing capacity. This alludes to a symbiotic relationship between the user and the device and here we look at this symbiotic relationship from an end user perspective. Thus, in order to have a successful interaction, we argue that the user needs to feel comfortable wearing the device while carrying out the intended tasks. We hypothesize that this perceived comfort is dependent on the context in which the device is used. We test our hypothesis on three different scenarios; search and rescue worker, dementia patient in a long care facility and a person at a party which acts as the baseline. Results indicate an important consequence for the development of such wearable robotic systems.
Khushaba, RN, Kodagoda, S, Lal, S, Dissanayake, G & IEEE 1970, 'Intelligent Driver Drowsiness Detection System Using Uncorrelated Fuzzy Locality Preserving Analysis', 2011 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Francisco, USA, pp. 4608-4614.
View/Download from: Publisher's site
View description>>
One of the leading causes of automobile accidents is related to driving impairment due to drowsiness. A large percentage of these accidents occur due to drivers' unawareness of the degree of impairment. An automatic detection of drowsiness levels could lead to lower accidents and hence lower fatalities. However, the significant fluctuations of the drowsiness state within a short time poses a major challenge in this problem. In response to such a challenge, we present the Uncorrelated Fuzzy Locality Preserving Analysis (UFLPA) feature projection method. The proposed UFLPA utilizes the changes in driver behavior, by means of the corresponding Electroencephalogram (EEG), Electrooculogram (EOG), and Electrocardiogram (ECG) signals to extract a set of features that can highly discriminate between the different drowsiness levels. Unlike existing methods, the proposed UFLPA takes into consideration the fuzzy nature of the input measurements while preserving the local discriminant and manifold structures of the data. Additionally, UFLPA also utilizes Singular Value Decomposition (SVD) to avoid the singularity problem and produce a set of uncorrelated features. Experiments were performed on datasets collected from thirty-one subjects participating in a simulation driving test with practical results indicating the significance of the results achieved by UFLPA of 94%â95% accuracy on average across all subjects.
Khushaba, RN, Kodagoda, S, Liu, D & Dissanayake, G 1970, 'Electromyogram (EMG) based fingers movement recognition using Neighborhood Preserving Analysis with QR-decomposition', 2011 Seventh International Conference on Intelligent Sensors, Sensor Networks and Information Processing, 2011 Seventh International Conference on Intelligent Sensors, Sensor Networks and Information Processing (ISSNIP), IEEE, Adelaide - Australia, pp. 1-6.
View/Download from: Publisher's site
View description>>
Surface Electromyogram (EMG) signals recorded from an amputee's residual muscles have been investigated as a source of control for prosthetic devices for many years. Despite the extensive research focus on the EMG control of arm and gross hand movements, more dexterous individual and combined prosthetic fingers control has not received the same amount of attention. To facilitate such a control scheme, the first and the most significant step is the extraction of a set of highly discriminative feature set that can well separate between the different fingers movements and to do so in a computationally efficient manner. In this paper, an accurate and efficient feature projection method based on Fuzzy Neighborhood Preserving Analysis (FNPA) with QR-decomposition, is proposed and denoted as FNPA. Unlike existing attempts in fuzzy linear discriminant analysis, the objective of the proposed FNPA is to minimize the distance between samples that belong to the same class and maximize the distance between the centers of different classes, while taking into account the contribution of the samples to the different classes. The method also aims to efficiently overcome the singularity problems of classical LDA and Fuzzy LDA. The proposed FNPA is validated on EMG datasets collected from nine subjects performing 10 classes of individual and combined fingers movements. Practical results indicate the significance of FNPA in comparison to many other feature projection methods with an average accuracy of 91%, using only two EMG electrodes. © 2011 IEEE.
Kim, S & Kim, J 1970, 'Towards large-scale occupancy map building using Dirichlet and Gaussian processes', Proceedings of the 2011 Australasian Conference on Robotics and Automation, pp. 4756-4761.
View description>>
This paper proposes a new method for building occupancy maps using Dirichlet and Gaussian processes. We consider occupancy map building as a classification problem and apply Gaussian processes. The main drawback of Gaussian processes, however, is the computational complexity of O(n 3) related to the matrix inversion, where n is the number of data points. To enable large-scale occupancy map building, we propose to use Dirichlet process mixture models which cluster input data without fixing the number of clusters a priori and to apply a mixture of Gaussian processes for the clustered data. This approach also has an advantage of dealing with local discontinuities better than one global Gaussian process model. Simulation results will be provided demonstrating the benefits of the approach.
Kirchner, N, Alempijevic, A & Dissanayake, G 1970, 'Nonverbal robot-group interaction using an imitated gaze cue', Proceedings of the 6th international conference on Human-robot interaction, HRI'11: International Conference on Human-Robot Interaction, ACM, Lausanne, Switzerland, pp. 497-504.
View/Download from: Publisher's site
View description>>
Ensuring that a particular and unsuspecting member of a group is the recipient of a salient-item hand-over is a complicated interaction. The robot must effectively, expediently and reliably communicate its intentions to advert any tendency within the group towards antinormative behaviour. In this paper, we study how a robot can establish the participant roles of such an interaction using imitated social and contextual cues. We designed two gaze cues, the first was designed to discourage antinormative behaviour through individualising a particular member of the group and the other to the contrary. We designed and conducted a feld experiment (456 participants in 64 trials) in which small groups of people (between 3 and 20 people) assembled in front of the robot, which then attempted to pass a salient object to a particular group member by presenting a physical cue, followed by one of two variations of a gaze cue. Our re-sults showed that presenting the individualising cue had a significant (z=3.733, p=0.0002 ) effect on the robot's ability to ensure that an arbitrary group member did not take the salient object and that the selected participant did.
Kuo, V, Fitch, R & IEEE 1970, 'A Multi-Radio Architecture for Neighbor-to-Neighbor Communication in Modular Robots', 2011 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA), IEEE International Conference on Robotics and Automation, IEEE, Shanghai, China, pp. 5387-5394.
View/Download from: Publisher's site
View description>>
Decentralized control of modular robots requires reliable inter-module communication. Communication links must tolerate module misalignment and implement the neighbor-to-neighbor communication model. We propose a wireless system based on multiple radios per module that addresses these challenges. Our system scales to large robots because available bandwidth is independent of the number of modules. In this paper, we present our multi-radio singlechannel architecture and validate its performance through hardware experiments. Results show that radios can provide reliable neighbor-to-neighbor communication suitable for modular robots. © 2011 IEEE.
Liu, M, Huang, S, Dissanayake, G & IEEE 1970, 'Feature Based SLAM Using Laser Sensor Data with Maximized Information Usage', 2011 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA), IEEE International Conference on Robotics and Automation, IEEE, Shanghai, China, pp. 1811-1816.
View/Download from: Publisher's site
View description>>
This paper formulates the SLAM problem using 2D laser data as an optimization problem. The environment is modeled as a set of curves and the variables of the optimization problem are the robot poses as well as the parameters describing the curves. There are two key differences between this SLAM formulation and existing SLAM methods. First, the environment is represented by continuous curves instead of point clouds or occupancy grids. Second, all the laser readings, including laser beams which returns its maximum range value, have been included in the objective function. As the objective function to be optimized contains discontinuities, it can not be solved by standard gradient based approaches and thus a Genetic Algorithm (GA) based method is applied. Matching of laser scans acquired from relatively far apart robot poses is achieved by applying GA on top of the Iterative closest point (ICP) algorithm. The new SLAM formulation and the use of a global optimization algorithm successfully avoid the convergence to local minimum for both the scan matching and the SLAM problem. Both simulated and experimental data are used to demonstrate the effectiveness of the proposed techniques. © 2011 IEEE.
Lozano, A, Peters, G & Liu, D 1970, 'Analysis of an Arthropodal System for Design of a Climbing Robot', Proceedings of the International Symposium on Automation and Robotics in Construction (IAARC), 28th International Symposium on Automation and Robotics in Construction, International Association for Automation and Robotics in Construction (IAARC), Seoul, Korea, pp. 832-838.
View/Download from: Publisher's site
View description>>
This paper will discuss research on ant locomotion, especially in climbing adaptability and transversing steel bridge configurations, for the design of a climbing robot for inspection and condition assessment of complex steel bridge structures. Experiments in ant locomotion were performed and captured using high-speed video equipment capable of recording at 1000fps. Analysis of the data found that certain body postures in ants are adopted before proceeding with their intended direction, such as when climbing a vertical obstacle. Information on ant body posture, compliance and movement in climbing will also be presented. Furthermore, the working volumes of ant leg pairs are determined through computer aided analysis, which provides essential data for determining possible ant foot positions for locomotion. Discussions on how the findings can be used in designing a climbing robot is also presented.
LOZANO, A, PETERS, G, LIU, D & WALDRON, K 1970, 'STUDY OF ANT LOCOMOTION IN SURFACE TRANSITIONS FOR CLIMBING ROBOT DESIGN', Field Robotics, Proceedings of the 14th International Conference on Climbing and Walking Robots and the Support Technologies for Mobile Machines, WORLD SCIENTIFIC, Paris, France, pp. 174-181.
View/Download from: Publisher's site
View description>>
Many climbing robots designed based on simple representations of the arthropod body have proven to be able to move on relatively flat surfaces and simple environments. However these robots are not able to navigate in complex environments such as steel bridges. This paper presents experimental studies on ant locomotion, particularly focusing on ant leg gait and posture when traversing a variety of complex surfaces, with the aim of providing climbing robot designers a better understanding of biological ant locomotion through a complex terrain. © 2012 by World Scientific Publishing Co. Pte. Ltd.
Manamperi, P, Brooks, PA, Kaluarachchi, W, Peters, G, Ho, A, Lie, S, To, AW, Paul, G, Rushton-Smith, D, Webb, SS, Liu, D & Dissanayake, G 1970, 'Robotic Grit-blasting: Engineering Challenges', Austroads 8th Bridge Conference: Sustainable Bridges: The Thread of Society, Austroads Bridge Conference, 2011 Austroads Bridge Conference (ABC 2011), Sydney, Australia, pp. 321-330.
View description>>
Infrastructure shortage and aging are worldwide issues. Australia, in particular, faces unique challenges in maintaining infrastructures such as roadways and bridges. Corrosion is the primary cause of failure in steel bridges, and is minimised by painting the steel structure. Stripping of rust and deteriorated paint by grit-blasting is an effective and practical method. However, grit-blasting operation is extremely labour intensive and hazardous. It is one of the biggest expenditure items in bridge maintenance operations. Robotics technologies can provide effective solutions to assist bridge maintenance workers in grit blasting. Since 2005, the NSW Roads & Traffic Authority (RTA) and the Centre of Excellence for Autonomous Systems at the University of Technology, Sydney have been working together in developing a robotic system for assisting bridge maintenance workers, with the ultimate objective of preventing human exposure to hazardous and dangerous dust containing rust, paint particles and lead, relieving human workers from labor intensive tasks, and reducing costs associated with bridge maintenance. A prototype robotic system has been developed and tested in both lab setup and on-site. Many engineering issues have been identified for deploying such a system in the field. This paper will present these issues and discuss the solutions.
Miro, JV, Black, R, De Bruijn, F, Dissanayake, G & IEEE 1970, 'Semi-Autonomous Competency Assessment of Powered Mobility Device Users', 2011 IEEE INTERNATIONAL CONFERENCE ON REHABILITATION ROBOTICS (ICORR), IEEE International Conference on Rehabilitation Robotics, IEEE, Zurich, Switzerland, pp. 1-6.
View/Download from: Publisher's site
View description>>
This paper describes a stand-alone sensor package and algorithms for aiding the assessment by an occupational therapist whether a person has the capacity to safely and effectively operate a powered mobility device such as a walking aid or a wheelchair. The sensor package employed consists of a laser range finder, an RGB camera and an inertial measurement unit that can be attached to any mobility device with minimal modifications. Algorithms for capturing the data received by the sensor package and for generating the map of the environment as well as the trajectory of the mobility device have been developed. Such information presents occupational therapists with the capability to provide a quantitative assessment of whether patients are ready to be safely deployed with mobile aids for their daily activities. Preliminary evaluation of the sensor package and associated algorithms based on experiments, conducted at the premises of the Prince of Wales Hospital in Sydney, are presented. © 2011 IEEE.
Miro, JV, Zhou, W, Dissanayake, G & IEEE 1970, 'A Strategy for Efficient Observation Pruning in Multi-Objective 3D SLAM', 2011 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Francisco, CA, USA, pp. 1640-1646.
View/Download from: Publisher's site
View description>>
An efficient automatic solution to the feature-based simultaneous localisation and mapping (SLAM) of mobile robots operating in conditions where a number of competing objectives operate simultaneously is proposed. The formulation quantitatively measures the merit of incoming data with respect to multiple priorities, automatically adjusting the amount of observations to be used in the estimation process for the best possible combined outcome. The methodology enables a selection mechanism which can efficiently exploit the observations available to the robot to best fulfil the objectives of differing tasks throughout the course of a mission, e.g. localisation, mapping, exploration, feature distribution, searching for specific objects or victims, etc. The work is particularly motivated by navigation in three-dimensional terrains, and an example considering the objectives of robot localisation and map expansion in a search and rescue environment using an RGB-D camera is utilised for discussion and results. © 2011 IEEE.
Nieto, JI, Agamennoni, G & Vidal-Calleja, T 1970, 'Loop-closure candidates selection by exploiting structure in vehicle trajectory', 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011), IEEE, San Francisco, CA, pp. 92-97.
View/Download from: Publisher's site
View description>>
One of the most important problems in robot localisation is the detection of previously visited places (loops). When a robot closes a loop, the association between observed features and present ones can be used to update its position. The computational cost involved in the association process makes exhaustive loop search intractable. Most of the current techniques use observations of the environment as their main features to produce loop hypotheses. In this paper, we investigate the feasibility of producing loop candidates from features of the robot trajectory. We propose a new method for selecting loop-closure candidates based on an alignment likelihood function, which measures similarity between trajectory sequences. The algorithm is validated with data gathered in the city with our experimental platform. Positive results show that the trajectory has, indeed, features that can be extracted and applied to robot localisation. The resulting loop hypotheses may be regarded, for example, as a initialisation step to aid current methods. © 2011 IEEE.
O'Callaghan, ST, Singh, SPN, Alempijevic, A & Ramos, FT 1970, 'Learning navigational maps by observing human motion patterns', 2011 IEEE International Conference on Robotics and Automation, 2011 IEEE International Conference on Robotics and Automation (ICRA), IEEE, Shanghai, China, pp. 4333-4340.
View/Download from: Publisher's site
View description>>
Observing human motion patterns is informative for social robots that share the environment with people. This paper presents a methodology to allow a robot to navigate in a complex environment by observing pedestrian positional traces. A continuous probabilistic function is determined using Gaussian process learning and used to infer the direction a robot should take in different parts of the environment. The approach learns and filters noise in the data producing a smooth underlying function that yields more natural movements. Our method combines prior conventional planning strategies with most probable trajectories followed by people in a principled statistical manner, and adapts itself online as more observations become available. The use of learning methods are automatic and require minimal tuning as compared to potential fields or spline function regression. This approach is demonstrated testing in cluttered office and open forum environments using laser and vision sensing modalities. It yields paths that are similar to the expected human behaviour without any a priori knowledge of the environment or explicit programming.
Patel, M, Valls Miro, J & Dissanayake, G 1970, 'Activity recognition from the interactions between an assistive robotic walker and human users', Proceedings of the 6th international conference on Human-robot interaction, HRI'11: International Conference on Human-Robot Interaction, ACM, Lausanne, Switzerland, pp. 221-222.
View/Download from: Publisher's site
View description>>
Detection of individuals' intention from a sequence of actions is an open and complex problem. In this paper we present a smart walker as mobility aid which can interpret the users' behaviour patterns to recognize their intentions and consequently act as an intelligent assistant. The result of the experiments performed in this paper demonstrates the potential of dynamic bayesian networks (DBN), in relation to their dynamic and unsupervised nature, for realistic human-robot interaction modelling.
Peynot, T, Fitch, R, McAllister, R & Alempijevic, A 1970, 'Autonomous Reconfiguration of a Multi-Modal Mobile Robot', Workshop on Automated Diagnosis, Repair and Re-Configuration of Robot Systems, IEEE International Conference on Robotics and Automation (ICRA), IEEE International Conference on Robotics and Automation, IEEE, Shanghai, China.
Qayyum, U & Kim, J 1970, 'Visual-Inertial Motion Priors for Robust Monocular SLAM', Conference Towards Autonomous Robotic Systems, Springer Berlin Heidelberg, Springer, Berlin, Heidelberg, pp. 430-431.
View/Download from: Publisher's site
Qayyum, U & Kim, J 1970, 'Visual-odometry integrated inertial-SLAM', International Symposium on Global Navigation Satellite Systems, Sydney, International Global Navigation Satellite Systems Society.
Sankaran, S, Gardiner, G & Sankaran, G 1970, 'Save me time: Make me famous', Proceedings of the New Horizons for Editing and Publishing Conference, Society of Editors, Sydney, pp. 1-12.
View description>>
Journals, conference proceedings and books are freely available online to readers worldwide via the new open access approach to scholarly publishing. Seen as a threat by commercial publishers, especially the high-cost STM (scientific, technical and medical) journal publishers, open access has grown apace over the past decade with many journals developing high status. UTSePress is an initiative of the University of Technology Sydney (UTS) and is the leading Australasian publisher of online, open access, peer-reviewed journals, with 14 titles being currently published. It is managed by UTS library staff, using software developed by the Public Knowledge Project, and its journals are edited by academics at UTS and elsewhere. The journals cover a diverse range of disciplines, including governance, ICT (information and communications technology), international studies, history, law, literacy, project management, construction and engineering, and society and social justice. Editorial boards, authors and reviewers are drawn from the respective scholarly fields internationally. This paper will explore the pros and cons of open access online publishing, covering issues such as new business models and their implications for authors, editors and readers. The paper draws on the expertise and experience of the journal managers and editors, as well as the library staff managing the project. It will broadly explore the issues faced by all the UTSePress journals and also provide a case study focusing on one of the newest journals, the Journal of Project, Program and Portfolio Management.
Sehestedt, S, Kodagoda, S & Dissanayake, G 1970, 'Robust people tracking and SHMM learning using SHMMs', Proceedings of the 2011 Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Australian Robotics and Automation Association Inc., Melbourne, pp. 1-6.
View description>>
For effective Human Robot Interaction (HRI), it is necessary for the robot to be aware of its human peers and be able to anticipate and predict their actions. This paper explores an improved strategy for people tracking using Sampled Hidden Markov Models (SHMM) for capturing common human motion patterns. Such an SHMM contains rich information about human spatial behavior and it can be learned online during robot operation. The proposed integration of people tracking and learning offers significant improvements to the outcomes when compared to existing techniques. Real world experiments that demonstrate the viability and effectiveness of the approach are presented.
Shi, L, Kodagoda, S & Ranasinghe, R 1970, 'Fast indoor scene classification using 3D point clouds', Proceedings of the 2011 Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, The ACRA 2011 Organising Committee, Monash University, Melbourne Australia, pp. 1-7.
View description>>
A representation of space that includes both geometric and semantic information enables a robot to perform high-level tasks in complex environments. Identifying and categorizing environments based on onboard sensors are essential in these scenarios. The Kinect™, a 3D low cost sensor is appealing in these scenarios as it can provide rich information. The downside is the presence of large amount of information, which could lead to higher computational complexity. In this paper, we propose a methodology to efficiently classify indoor environments into semantic categories using Kinect™ data. With a fast feature extraction method along with an efficient feature selection algorithm (DEFS) and, support vector machines (SVM) classifier, we could realize a fast scene classification algorithm. Experimental results in an indoor scenario are presented including comparisons with its counterpart of commonly available 2D laser range finder data.
Taha, T, Miro, JV, Dissanayake, G & IEEE 1970, 'A POMDP Framework for Modelling Human Interaction with Assistive Robots', 2011 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA), IEEE International Conference on Robotics and Automation, IEEE, Shanghai, China, pp. 544-549.
View/Download from: Publisher's site
View description>>
This paper presents a framework for modelling the interaction between a human operator and a robotic device, that enables the robot to collaborate with the human to jointly accomplish tasks. States of the system are captured in a model based on a partially observable Markov decision process (POMDP). States representing the human operator are motivated by behaviours from the psychology of the human action cycle. Hierarchical nature of these states allows the exploitation of data structures based on algebraic decision diagrams (ADD) to efficiently solve the resulting POMDP. The proposed framework is illustrated using two examples from as-sistive robotics; a robotic wheel chair and an intelligent walking device. Experimental results from trials conducted in an office environment with the wheelchair is used to demonstrate the proposed technique. © 2011 IEEE.
Valls Miro, J, De Bruijn, F, Dissanayake, G, Boisard, O & Ton, P 1970, 'Robot-Assisted Inspection of Concrete Box Girders in Bridges', Proceedings for the Austroads Conference 2011: Sustainable Bridges - The Thread of Society, Austroads Bridge Conference, Austroads Ltd., Sydney, pp. 335-346.
View description>>
This paper describes a robotic solution to the structural health inspection of concrete box girders. A combination of sensors including a laser range finder, a depth (RGB-D) camera, an inertial measurement unit and a high-resolution camera are mounted on a tracked robot. The robot can be driven inside a box girder even when there are steps present, to collect high-resolution images of the concrete structure. Software that allows the information captured to be registered with a 3D geometric map of the inside of a box girder, and a visualization tool that can be used to evaluate location-annotated highly-detailed surface condition pictures by the human operator has been developed. The proposed remote evaluation technique makes it feasible to safely monitor areas over a sequence of inspections, leading to more effective maintenance procedures. The effectiveness of the system is illustrated using data gathered during a field trial where the robot was deployed within the Overpass at Huntleyâs Point, in the junction between Victoria Road and Burns Bay Road in Sydney. Functionality to automatically identify defects/regions of interest is also being investigated. It is anticipated that supplementing manual inspection tasks with robotic aids will mitigate the risk to manual entry into a confined space with a consequential saving in associated cost. This project is collaboration between the University of Technology Sydney (UTS) and the Roads & Traffic Authority (RTA) of NSW.
Valls Miro, J, Zhou, W & Dissanayake, G 1970, 'A strategy for efficient observation pruning in multi-objective 3D SLAM', 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2011), IEEE.
View/Download from: Publisher's site
Vidal, T, Berger, C, Sola, J & Lacroix, S 1970, 'Environment Modeling for Cooperative Aerial/Ground Robotic Systems', Springer Berlin Heidelberg, pp. 681-696.
View/Download from: Publisher's site
Wang, S, Kodagoda, S, Wang, Z & Dissanayake, G 1970, 'Multiple sensor based terrain classification', Proceedings of the 2011 Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Australasion Conference on Robotics and Automation, Melbourne, Australia, pp. 1-7.
View description>>
In the context of road vehicles, knowledge of terrain types is useful for improving passenger safety and comfort. This paper presents a method for terrain classification based on multiple sensors including an accelerometer, wheel encoders and a camera. The vertical accelerations and the speed of the vehicle together with a dynamic vehicle model are used to predict the road profile. Features extracted from the road profile are fused with image features to produce a speed invariant feature set. A supervised learning algorithm based on Neural network (NN) is used to classify different road types. Experiments carried out on an instrumented road vehicle (CRUISE), by manually driving on a variety of road types at different speeds are presented to demonstrate that the fusion of multiple sensory cues can significantly improve the road type classification accuracy.
Zhao, L, Huang, S, Yan, L, Dissanayake, G & IEEE 1970, 'Parallax Angle Parametrization for Monocular SLAM', 2011 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA), IEEE International Conference on Robotics and Automation, IEEE, Shanghai, China, pp. 3117-3124.
View/Download from: Publisher's site
View description>>
This paper presents a new unified feature para-metrization approach for monocular SLAM. The parametrization is based on the parallax angle and can reliably represent both nearby and distant features, as well as features in the direction of camera motion and features observed only once. A new bundle adjustment (BA) algorithm using the proposed parallax angle parametrization is developed and shown to be more reliable as compared with existing BA algorithms that use Euclidean XYZ or inverse depth parametrizations. A new map joining algorithm that allows combining a sequence of local maps generated using BA with the proposed parametrization, that avoids the large computational cost of a global BA, and can automatically optimize the relative scales of the local maps without any loss of information, is also presented. Extensive simulations and a publicly available large-scale real dataset with centimeter accuracy ground truth are used to demonstrate the accuracy and consistency of the BA and map joining algorithms using the new parametrization. Especially, since the relative scales are optimized automatically in the proposed BA and map joining algorithms, there is no need to compute any relative scales even for a loop more than 1km. © 2011 IEEE.
