Crowther, A, Zhang, N, Liu, DK & Jeyakumaran, JK 2004, 'Analysis and simulation of clutch engagement judder and stick-slip in automotive powertrain systems', Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, vol. 218, no. 12, pp. 1427-1446.
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Clutch engagement judder and stick—slip are investigated analytically and numerically to examine the influencing factors on these phenomena. Models are developed for a four degree-of- freedom (4DOF) torsional system with slipping clutch and for a powertrain with automatic transmission system. Stability analysis is performed to demonstrate that clutch judder is dependent on the slope of the friction coefficient and the analysis is verified with numerical simulations. An algorithm for modelling stick—slip is developed and is used in numerical simulations which show that the likelihood of stick—slip is increased by clutch pressure fluctuations, judder approaching engagement, and external torque fluctuations. Numerical simulations for second to third gear up shifts demonstrate that the likelihood of stick—slip to occur from clutch engagement is increased by clutch applied pressure fluctuations, judder approaching engagement, and external torque fluctuations and that the likelihood of stick—slip occurring is decreased dramatically by applied pressure ramps proximus to the engagement point.
Eager, DM 2004, 'The Low Down On Playground Undersurfing', Journal of the Australian Institute of Landscape Architects, vol. 26, no. 2, pp. 54-56.
Han, J, Wei, D & Zhang, Y 2004, 'Physical and numerical simulation for inner crack healing in metals', Shanghai Jiaotong Daxue Xuebao/Journal of Shanghai Jiaotong University, vol. 38, no. SUPPL., pp. 130-135.
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The research purpose on the healing of inner crack in metallic materials is to provide an effective approach for improving their properties and prolonging their lifetime. The crack healing process of 20MnMo steel with inner pre-crack was analyzed. It was found that all inner cracks could be healed in different degree. There were very fine ferrite grains in healing region. The micro-crack healing process in single crystal of BBC-Fe was simulated by the molecule dynamics method, which shows that the critical temperature of crack healing in BBC-Fe is 673 K. There were micro-voids, dislocations and twins left after crack healing.
Huynh, P & Loe, S 2004, 'Influence of location, number and shape of corrugations in slider bearings', ANZIAM Journal, vol. 45, pp. 1017-1038.
Jain, V, Saha, SC, Bagga, R & Gopalan, S 2004, 'Unsafe abortion: A neglected tragedy. Review from a tertiary care hospital in India', Journal of Obstetrics and Gynaecology Research, vol. 30, no. 3, pp. 197-201.
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AbstractAim: With 16% of the world's population, India accounts for over 20% of the world's maternal deaths. The maternal mortality ratio, defined as the number of maternal deaths per 100 000 live births is incredibly high at 408 per 100 000 live births for the country. Abortion has been legalized in India for the past three decades. However, the share of unsafe abortion as a cause of maternal mortality continues to be alarming. The objective of the present study is to identify the magnitude of problem of unsafe abortion in India.Methods: Emergency gynecologic admissions to a tertiary care center in North India over a 15‐year period (1988–2002) were reviewed to evaluate the demographic and clinical profile of patients admitted as a result of unsafe abortion. The records were analyzed with regard to the age group, parity and marital status of the abortion seekers, the indication of abortion, the methods used, qualification of abortion providers, complications and fatality rate.Results: The majority of women who were admitted with diagnosis of unsafe abortion were in the third decade of their lives. They were married, multiparous women living with their spouses. Sixty percent of the women had approached unqualified abortion providers who used primitive methods of pregnancy termination. All the women were admitted with serious complications of unsafe abortions and one‐fourth of them succumbed to the complications.Conclusion: Unsafe abortion constitutes a major threat to the health and lives of women. This study highlights the need to focus more directly on the needs and preferences of women who seek abortion as well as on the accessibility of contraceptives and skills of the providers of abortion services, in order to improve the quality of abortion care.
Ji, JC 2004, 'Dynamics of a piecewise linear system subjected to a saturation constraint', JOURNAL OF SOUND AND VIBRATION, vol. 271, no. 3-5, pp. 905-920.
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The dynamics of a periodically forced single-degree-of-freedom linear system with a proportional feedback control subjected to a saturation constraint is investigated in detail. Emphasis is placed on the determination of a double-entering saturation region per cycle periodic motion. Symmetric period-one solutions are derived analytically and their stability characteristics are determined. Other kinds of solutions such as asymmetric, subharmonic and chaotic solutions as well as multiple-crossing saturation region per cycle periodic solutions, found through numerical simulations, are also presented.
Ji, JC & Hansen, CH 2004, 'Analytical approximation of the primary resonance response of a periodically excited piecewise non-linear-linear oscillator', JOURNAL OF SOUND AND VIBRATION, vol. 278, no. 1-2, pp. 327-342.
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An analytical approximate solution is constructed for the primary resonance response of a periodically excited non-linear oscillator, which is characterized by a combination of a weakly non-linear and a linear differential equation. Without eliminating the secular terms, a valid asymptotic expansion solution for the weakly non-linear equation is analytically determined for the case of primary resonances. Then, a symmetric periodic solution for the overall system is obtained by imposing continuity and matching conditions. The stability characteristic of the symmetric periodic solution is investigated by examining the asymptotic behaviour of perturbations to the steady state solution. The validity of the developed analysis is highlighted by comparing the first order approximate solutions with the results of numerical integration of the original equations.
Ji, JC & Hansen, CH 2004, 'Approximate solutions and chaotic motions of a piecewise nonlinear-linear oscillator', CHAOS SOLITONS & FRACTALS, vol. 20, no. 5, pp. 1121-1133.
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A global symmetric period-1 approximate solution is analytically constructed for the non-resonant periodic response of a periodically excited piecewise nonlinear-linear oscillator. The approximate solutions are found to be in good agreement with the exact solutions that are obtained from the numerical integration of the original equations. In addition, the dynamic behaviour of the oscillator is numerically investigated with the help of bifurcation diagrams, Lyapunov exponents, Poincare maps, phase portraits and basins of attraction. The existence of subharmonic and chaotic motions and the coexistence of four attractors are observed for some combinations of the system parameters. © 2003 Elsevier Ltd. All rights reserved.
Ji, JC & Leung, AYT 2004, 'Periodic and chaotic motions of a harmonically forced piecewise linear system', International Journal of Mechanical Sciences, vol. 46, no. 12, pp. 1807-1825.
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The dynamics of a harmonically excited single degree-of-freedom linear system with a feedback control, in which the actuator is subjected to dead zone and saturation constraints, is investigated in detail. The controlled system is mathematically modeled by a set of three piecewise linear equations. It is found that the system may exhibit nine types of symmetric and asymmetric period-one motions, which are characterized by a different number of crossing dead zone and saturation region per cycle. A solution for the symmetric period-one motion with a doubly crossing dead zone and saturation region is analytically constructed and its stability characteristics is examined. Other types of dynamic response such as sub-harmonic periodic motions and chaotic motions, found through numerical simulations, are also presented.
Ji, JC & Leung, AYT 2004, 'Periodic and chaotic motions of a harmonically forced piecewise linear system', INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, vol. 46, no. 12, pp. 1807-1825.
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Leung, AYT, Ji, JC & Chen, GR 2004, 'Resonance control for a forced single-degree-of-freedom nonlinear system', INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS, vol. 14, no. 4, pp. 1423-1429.
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The main characteristic of a forced single-degree-of-freedom weakly nonlinear system is determined by its primary, super- and sub-harmonic resonances. A nonlinear parametric feedback control is proposed to modify the steady-state resonance responses, thus to reduce the amplitude of the response and to eliminate the saddle-node bifurcations that take place in the resonance responses. The nonlinear gain of the feedback control is determined by analyzing the bifurcation diagrams associated with the corresponding frequency-response equation, from the singularity theory approach. It is shown by illustrative examples that the proposed nonlinear feedback is effective for controlling three kinds of resonance responses.
Li, QS, Liu, DK, Tang, J, Zhang, N & Tam, CM 2004, 'Combinatorial optimal design of number and positions of actuators in actively controlled structures using genetic algorithms', Journal of Sound and Vibration, vol. 270, no. 4-5, pp. 611-624.
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In this paper, the optimal design of the numbers and positions of actuators in actively controlled structures is formulated as a three-level optimal design problem. Features of this design problem such as discreteness, multi-modality and hierarchical structure are discussed. A two-level genetic algorithm (TLGA) is proposed for solving this problem. The concept, principle and solution process of the TLGA are described. A case study is presented, in which a building is subjected to earthquake excitation and controlled by active tendon actuators. The results of this study show that: (1) the design problem for optimizing number and configuration of actuators simultaneously in actively controlled structures has the features of non-linearity, mixed-discreteness and multi-modality; (2) a three-level design model can give a reasonable description for this kind of design problem; (3) TLGA is an effective algorithm for solving the combinatorial optimization problem. © 2003 Elsevier Ltd.
Luo, Q & Tong, L 2004, 'An accurate laminated element for piezoelectric smart beams including peel stress', Computational Mechanics, vol. 33, no. 2, pp. 108-120.
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Luo, Q & Tong, L 2004, 'An adhesively laminated plate element for PZT smart plates', Computational Mechanics, vol. 34, no. 3, pp. 224-236.
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Luo, Q & Tong, L 2004, 'Linear and higher order displacement theories for adhesively bonded lap joints', International Journal of Solids and Structures, vol. 41, no. 22-23, pp. 6351-6381.
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This work presents an adhesive model for stress analysis of bonded lap joints, which can be applied to model thin and thick adhesive layers. In this theory, linear variations of displacement components along the adhesive thickness are firstly assumed, and the longitudinal strain and the Poisson's effect of the adhesive are modeled. A differential form of the equilibrium equations for the adherends is analytically solved by means of compatible relations of the adhesive deformation. The derived shear and peel stresses are compared with the classical adhesive model of continuous springs with constant shear and peel stresses, and validated with two-dimensional finite element results of the geometrically nonlinear analysis using a commercial package. The numerical results show that the present linear displacement theory can be applied to both thin and moderately thick adhesive layers. The present formulation of the linear displacement theory is then extended to the higher order displacement theory for stress analysis of a thick adhesive, whose numerical results are also compared with those of the finite element computation. © 2004 Elsevier Ltd. All rights reserved.
Nixon, JW, Acton, CHC, Wallis, BA, Battistutta, D, Perry, C & Eager, DBM 2004, 'Preventing injuries on horizontal ladders and track rides', Injury Control and Safety Promotion, vol. 11, no. 4, pp. 219-224.
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OBJECTIVES: This study examined the type of injury, fall heights and measures of impact attenuation of surfaces on which children fell from horizontal ladders and track rides. METHOD: All injured children who presented to two children's hospitals and received medical attention following a fall from a horizontal ladder or track ride in a public school or park during 1996--1997 were interviewed and the playground visited. RESULTS: The number of children who fell from horizontal ladders and track rides and presented to hospitals with injury was 118. Of those children, 105 were injured when they hit the ground and data were available on 102 of those playground undersurfaces. Fractures to the arm or wrist were the most common injury. The median height fallen by children was 1930 mm, 73% of injuries were from falls greater than 1800mm. In 41% of sites, the surface was deficient in impact absorbing properties for the height of the equipment. Fractures were no more likely on loose surfaces than other surfaces, such as rubber matting (p = 0.556) but more prevalent on compliant than non-compliant surfaces. Relative to falls occurring on noncompliant surfaces, the odds of a fracture occurring on a compliant surface was 2.67 (95% CI 0.88-8.14). CONCLUSIONS: Modification of the height of horizontal ladders and track rides to 1800mm is preferable to removal of such equipment. The prevalence of fractures on compliant surfaces suggests that the threshold of 200g or 1000 head injury criteria (HIC) needs to be revisited, or additional test criteria added to take account of change in momentum that is not presently accounted for with either g-max on HIC calculations.
Wei, D, Han, J, Tieu, K & Jiang, Z 2004, 'Simulation of crack healing in BCC Fe', Scripta Materialia, vol. 51, no. 6, pp. 583-587.
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Zhang, YJ, Han, JT & Wei, DB 2004, 'Inner variable of micro crack healing in metal and its evolvement', Journal of Iron and Steel Research, vol. 16, no. 2, pp. 59-62.
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The crack healing is a thermodynamic nonreversible process. A dissipation inequation for crack-healing is given based on the thermodynamics of continuous medium and second law of thermodynamics. A definition of inner variable to describle the crack-healing process is put forward. Based on the molecular dynamic simulation, the evolvement of inner variable of micro crack healing of pure copper is analysed quantitatively.
Alempijevic, A 1970, 'High-Speed Feature Extraction in Sensor Coordinates for Laser Rangefinders', Conference Proceedings, Australasian Conference on Robotics and Automation (ACRA 2004), Australasian Conference on Robotics and Automation, Australian Robotics & Automation Association, Canberra, Australia, pp. 1-6.
Alempijevic, A, Dissanayake, G & IEEE 1970, 'An efficient algorithm for line extraction from laser scans', 2004 IEEE CONFERENCE ON ROBOTICS, AUTOMATION AND MECHATRONICS, VOLS 1 AND 2, IEEE Conference on Robotics, Automation and Mechatronics, IEEE R&A Society Singapore Chapter, Singapore, pp. 970-974.
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In this paper, an algorithm for extracting line segments from information gathered by a laser rangefinder is presented. The range scan is processed to compute a parameter that is invariant to the position and orientation of straight lines present. This parameter is then used to identify observations that potentially belong to straight lines and compute the slope of these lines. Log-Hough transform, that only explores a small region of the Hough space identified by the slopes computed, is then used to rind the equations of the lines present. The proposed method thus combines robustness of the Hough transform technique with the inherent efficiency of line fitting strategies while carrying out all computation in the sensor coordinate frame yielding a fast and robust algorithm for line extraction from laser range scans. Two practical examples are presented to demonstrate the efficacy of the algorithm and compare its performance to the traditional techniques.
Dissanayake, GM, Chen, L, Pedrycz, W, Fayek, AR & Russell, AD 1970, 'Fuzzy logic modeling of causal relationships-case study: Reasoning about construction performance', NAFIPS 2004: ANNUAL MEETING OF THE NORTH AMERICAN FUZZY INFORMATION PROCESSING SOCIETY, VOLS 1AND 2, Annual Meeting of the North-American-Fuzzy-Information-Processing-Society, IEEE, Banff, CANADA, pp. 605-610.
Eager, DM & Chapman, C 1970, 'Playground Surfacing Standards - A Discussion Paper', National Playground Conference, National Playground Conference, Kidsafe New South Wales Inc, Sydney, Australia, pp. 86-95.
Eager, DM & Chapman, C 1970, 'Why Bounce is Bad', National Playground Conference, National Playground Conference, Kidsafe New South Wales Inc, Sydney, Australia, pp. 186-199.
Furukawa, T, Bourgault, F, Durrant-Whyte, HF, Dissanayake, G & IEEE 1970, 'Dynamic allocation and control of coordinated UAVs to engage multiple targets in a time-optimal manner', 2004 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1- 5, PROCEEDINGS, IEEE International Conference on Robots and Automation, IEEE, New Orleans, pp. 2353-2358.
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This paper presents the real-time control of cooperative unmanned air vehicles (UAV) that dynamically engage multiple targets in a time-optimal manner. Techniques to dynamically allocate vehicles to targets and to subsequently find the time-optimal control actions are proposed. The decentralization of the proposed control strategy is further presented such that the vehicles can be controlled in real-time without significant time delay. The proposed strategy is men applied to various practical battlefield problems, and numerical results show the efficiency of the proposed strategy.
Gong, Z, Guzman, JI, Scheding, SJ, Rye, DC, Dissanayake, G & Durrant-Whyte, H 1970, 'A heuristic rule-based switching and adaptive PID controller for a large autonomous tracked vehicle: From development to implementation', Proceedings of the IEEE International Conference on Control Applications, IEEE International Conference on Control Applications, IEEE, Taipei,Taiwan, pp. 1272-1277.
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An innovative and effective algorithm to control the speed and heading of a large tracked vehicle is presented. This is part of a larger control system that converts a manual driving vehicle into a computer controlled platform to perform autonomous functions in unstructured jungle-like terrains. Heuristic rule-based switching and adaptive FID control methods are used in this algorithm. The control system has been physically implemented and extensive field trials proved that the algorithm is robust and effective with excellent performance under various terrain conditions. ©2004 IEEE.
Gu Fang, Dissanayake, G & Lau, H 1970, 'A behaviour-based optimisation strategy for multi-robot exploration', IEEE Conference on Robotics, Automation and Mechatronics, 2004., 2004 IEEE Conference on Robotics, Automation and Mechatronics, IEEE, Singapore, SINGAPORE, pp. 875-879.
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Ha, QP, Trinh, H & Dissanayake, G 1970, 'A low-order linear functional observer for time delay systems', 2004 5th Asian Control Conference, pp. 948-956.
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This paper presents an efficient technique to design loworder state function observers for linear time-delay systems. Assuming the existence of a linear state feedback controller to achieve stability or some control performance criteria of the time-delay system, a design procedure is proposed for reconstruction of the state feedback control action. The procedure involves solving an optimisation problem with the objective to generate a matrix that is as close as possible to the given feedback gain of the required feedback controller. A condition for robust stability of the time-delay system using the observer-based control scheme is given. The attractive features of the proposed design procedure are that the resulted linear functional state observer is of a very low order and it requires information of a small number of outputs. Numerical examples are given to demonstrate the design procedure and its merits.
Ha, QP, Trinh, HM & Dissanayake, G 1970, 'A Low-Order Linear Functional Observer for Time Delay Systems', Proceedings of the 5th Asian Control Conference, Asian Control Conference, IEEE, Melbourne, Australia, pp. 947-955.
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Scott, 1)there are two Names H Trinh as stapled to front yellow page. & 2) the page numbers are the same as physically on the print off of Ha's other Public in this Conf 'Simultaneous State... ' !!
Halkon, B & Rothberg, S 1970, 'Automatic post-processing of laser vibrometry data for rotor vibration measurements', IMechE Event Publications, 8th International Conference on Vibrations in Rotating Machinery, PROFESSIONAL ENGINEERING PUBLISHING LTD, Univ Wales Swansea, Swansea, WALES, pp. 215-230.
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The Laser Vibrometer constitutes a potentially powerful vibration transducer for measurements directly from rotating components. Radial, axial, pitch/yaw and torsional vibrations can all be measured using either single beam or parallel beam Laser Vibrometers. Successful application, however, requires a clear appreciation of the effects of laser speckle and of how radial and pitch/yaw vibration measurements from rotors contain significant cross-sensitivities to motion perpendicular to the intended measurement. Making use of two orthogonal vibration measurements and an independent speed measurement it is possible to eliminate cross-sensitivity from measured data at all non-synchronous frequencies but a convenient, practical means to undertake the necessary data processing has not been available until now. A Lab VIEW based real-time version of this essential resolution technique will be presented for the first time in this paper. This paper describes a number of example measurements. Radial and pitch/yaw vibration measurements will demonstrate the use of the resolution technique to show effects such as the excitation of the first bending mode of the crankshaft. A torsional vibration measurement on a crankshaft pulley will show the influence of speckle noise and alignment issues will be discussed to limit the pitch/yaw vibration sensitivity. Differential torsional measurements on rotating components can be used to examine, for example, the twisting across a flexible coupling and the stretching of a drive belt; speckle effects are again important. © IMechE 2004.
Halkon, BJ & Rothberg, SJ 1970, 'Synchronized-scanning laser vibrometry', SPIE Proceedings, Sixth International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, SPIE, Ancona, ITALY, pp. 260-271.
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The use of Laser Vibrometers incorporating some form of manipulation of the laser beam orientation, typically using two orthogonally aligned mirrors, has become increasingly popular in recent years with considerable attention being given to the operation of such scanning Laser Vibrometers in continuous scanning mode. Here the laser beam orientation is a continuous function of time, making it possible, for example, to track a single point on a moving target such as a rotating bladed disc. A recently derived comprehensive velocity sensitivity model has been developed to incorporate time-dependent beam orientation enabling confident and detailed analysis of data obtained in such measurements. The model predicts the measured velocity for arbitrary mirror scan angles and arbitrary target motion and is shown to be especially valuable in revealing the sources of additional components that occur in continuous scanning and tracking measurements on rotors. The development of the comprehensive velocity sensitivity model and of sophisticated measurement hardware and software has resulted in proposal of the exciting new Synchronised-Scanning Laser Vibrometry technique. Introduced for the first time in this paper, the measurement involves the probe laser beam tracking the rotating structure and simultaneously scanning the region of interest to provide modal data under operating conditions, i.e. during rotation. Such a measurement is inconceivable by any other means and the system that has been created has the potential to provide data of fundamental importance in the design and development of a wide range of devices from hard disk drives to gas turbines.
Huang, S, James, M & Jiang, Z 1970, 'L -Bounded Robust Control of Nonlinear Cascade Systems', Proceedings of the 5th Asian Control Conference, Asian Control Conference, ASCC 2004, Melbourne, Australia, pp. 531-538.
Huang, S, James, MR, Nesic, D & Dower, PM 1970, 'Measurement feedback controller design to achieve input to state stability', 2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601), 2004 43rd IEEE Conference on Decision and Control (CDC) (IEEE Cat. No.04CH37601), IEEE, Atlantis, Paradise Island, Bahamas, pp. 2515-2520.
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An approach for design of measurement feedback controllers achieving input-to-state (ISS) stability properties is presented. A synthesis procedure based on dynamic programming is given. We make use of recently developed results on controller synthesis to achieve uniform l∞ bound [6]. Our results make an important connection between the ISS literature and nonlinear H∞ design methods.
Jacobs, BJ & Brown, TA 1970, 'Addressing Inequities in Engineering Sketching Skills', Creating Flexible Learning Environments - proceedings of the 15th Australasian Conference for the Australasian Association for Engineering Education and the 10th Australasian Women in Engineering Forum, AAEE - Annual Conference of Australasian Association for Engineering Education, Australasian Association for Engineering Education, Toowoomba, Australia, pp. 18-28.
Kulatunga, AK, Liu, D & Dissanayake, G 1970, 'Simulated Annealing Algorithm Based Multi-Robot Coordination', Preprints of the 3rd IFAC Symposium on Mechatronic Systems, The 3rd IFAC Symposium on Mechatronic Systems, International Federation of Automatic Control (IFAC), Sydney, Australia, pp. 411-415.
Kwok, NM & Dissanayake, G 1970, 'An efficient multiple hypothesis filter for bearing-only SLAM', 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), IEEE, Sendai, Japan, pp. 736-741.
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This paper presents a multiple hypothesis approach to solve the simultaneous localisation and mapping (SLAM) problem with a bearing-only sensor. The main contribution of the paper is to provide a remedy for the landmark initialisation problem that occurs due to the absence of range information, in a computationally efficient manner. Each landmark is initialised in the form of multiple hypotheses distributed along the direction of the bearing measurement. Using subsequent measurements, the validity of the hypotheses is evaluated based on the sequential probability ratio test (SPRT). Consequently, the best approximation to the landmark location is maintained. This approach enables an extended Kalman filler (EKF) to be used for bearing-only SLAM providing a computational efficient solution. Simulation and experimental results, from using a camera as the bearing-only sensor mounted on a Pioneer robot are included to demonstrate the effectiveness of the proposed technique.
Kwok, NM, Liu, DK, Fang, G, Dissanayake, G & IEEE 1970, 'Path planning for bearing-only simultaneous localisation and mapping', 2004 IEEE CONFERENCE ON ROBOTICS, AUTOMATION AND MECHATRONICS, VOLS 1 AND 2, IEEE Conference on Robotics, Automation and Mechatronics, IEEE, Singapore, pp. 828-833.
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Simultaneous localisation and mapping (SLAM) is the process of estimating the pose of a mobile robot and the locations of landmarks by using sensors. When SLAM is cast as an information extraction procedure, its quality can be defined as the amount of uncertainty contained in the resultant estimation. Due to the characteristic of the bearing-only sensor and the geometry of the environment, the estimation uncertainty relies critically on the amount of information obtained from measurements and the efficiency of information extraction by the estimator. These quantities are dependent on the relative position between the robot and the landmarks, i.e., the path of the robot motion. Therefore, a well planned path of motion for the robot can significantly improve the SLAM quality. A genetic algorithm is adopted in this research to design a near-optimal one-step-ahead robot path subject to a multiple of planning objectives. The use of genetic algorithm together with a Pareto set, is proved to be efficient in reducing the estimation uncertainty and improving the quality of SLAM by simulation results.
Lim, SH, Furukawa, T, Dissanayake, G, Durrant-Whyte, HF & IEEE 1970, 'A time-optimal control strategy for pursuit-evasion games problems', 2004 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1- 5, PROCEEDINGS, IEEE International Conference on Robots and Automation, IEEE, New Orleans, USA, pp. 3962-3967.
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This paper presents a control strategy for the pursuer in the pursuit-evasion game problem when the evader behaves intelligently. The pursuer in the proposed technique does not try to react to the evader's behavior instantaneously. The proposed technique therefore does not yield instantaneous optimality but capture the evader in a time-efficient and robust fashion even when the evader is intelligent. The proposed technique was applied to two numerical examples and the results were compared to those by the conventional motion tracking algorithms. The results and comparison show that the proposed technique could capture the evader faster than the conventional motion tracking algorithms in both the examples.
Nguyen, A, Ha, QP, Huang, S & Trinh, HM 1970, 'Observer-Based Decentralized Approach to Robotic Formation Control', Conference Proceedings, Australasian Conference on Robotics and Automation (ACRA 2004), Australasian Conference on Robotics and Automation, ARAA Australian Robotics & Automation Association, Canberra, Australia, pp. 1-8.
Revel, A & Huynh, P 1970, 'Characterising Roof Ventilators', Proceedings of the Fifteenth Australasian Fluid Mechanics Conference, Australasian Fluid Mechanics Conference, The University of Sydney, Sydney, Australia, pp. 1-4.
Rothberg, SJ & Halkon, BJ 1970, 'Laser vibrometry meets laser speckle', SPIE Proceedings, Sixth International Conference on Vibration Measurements by Laser Techniques: Advances and Applications, SPIE, Ancona, ITALY, pp. 280-291.
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This paper begins with a review of the fundamental mechanism by which speckle noise is generated in Laser Vibrometry before describing a new numerical simulation of speckle behaviour for prediction of noise level in a real measurement. The simulation data provides real insight into the phase and amplitude modulation of the Doppler signal as a result of speckle changes. The paper also includes experimental data looking at the influence of speckle noise in measurements on rotors with a selection of surface treatments and in scanning and tracking configurations.
Rui Li, Chen, WM, Miao Yu & Liu, DK 1970, 'Fuzzy intelligent control of automotive vibration via Magneto-rheological damper', IEEE Conference on Cybernetics and Intelligent Systems, 2004., 2004 IEEE Conference on Cybernetics and Intelligent Systems, IEEE, Singapore, pp. 503-507.
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Based on analyses of characteristics of Magneto-Theological (MR) damper, a hierarchical fuzzy intelligent controller is proposed for vibration control of an automotive vehicle with MR dampers. This controller consists of control level and coordination level. In the control level, a semi-active fuzzy logic controller is designed for each MR suspension system based on a hybrid control strategy of sky-hook control and ground-hook control. In the coordination level, a coordination controller is designed to coordinate the four independent semi-active fuzzy logic controllers by adjusting their output parameters according to the system feedback. To validate the results of hierarchical fuzzy intelligent control, a MR semi-active suspension control and test system is set up and is implemented on a mini bus, which is equipped with four controllable MR dampers. Test results indicate that the hierarchical fuzzy intelligent controller can effectively reduce the vertical vibration and improve the ride comfort and handle stability of automobile.
Shoudong Huang, Zhan Wang & Dissanayake, G 1970, 'Time optimal robot motion control in simultaneous localization and map building (SLAM) problem', 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), IEEE, Sendai, Japan, pp. 3110-3115.
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This paper provides a technique for minimal time robot motion control in the estimation-theoretic based simultaneous localizations and map building (SLAM) problem. We consider the scenario that the robot needs to go to a destination which is a prescribed location in the coordinate system referenced by its starting position. The task of the robot is to reach the destination within minimal time while localizing itself and building a map of the environment with a prescribed accuracy. This task may be a real navigation task or may be a subtask in a SLAM problem of a large unknown environment. A global sub-optimal control law is derived using dynamic programming techniques.
Skinner, B, Nguyen, HT & Liu, D 1970, 'Performance Study of a Multi-Deme Parallel Genetic Algorithm with Adaptive Mutation', Proceedings of the 2nd International Conference on Autonomous Robots and Agents (ICARA'04), International Conference on Autonomous Robots and Agents, Massey University, Palmerston North, New Zealand, pp. 88-94.
Smith, DB, Abhayapala, TD & Aubrey, TA 1970, 'A generalised (M,NR) MIMO Rayleigh channel model for non-isotropic scatterer distributions.', Proceedings of Workshop on the Application of Radio Science, (WARS) 2004, Workshop on the Application of Radio Science, National Committee for Radio Science, Hobart, Australia, pp. 1-6.
Takezawa, S, Herath, DC & Dissanayake, G 1970, 'SLAM in indoor environments with stereo vision', 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), IEEE, Sendai, Japan, pp. 1866-1871.
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This paper proposes a method for simultaneous localisation and mapping (SLAM) in an indoor environment using stereo vision. Specially designed artificial landmarks distributed in the environment are observed and extracted from a camera image. The disparity map obtained from the stereo vision system is used to obtain the ranges to these landmarks. The main contribution of the paper is the formulation of the mathematical framework for SLAM for a robot moving on a planar surface among landmarks distributed in three dimensional space. The paper also presents the results of experiments conducted using a pioneer robot and a Triclops stereo vision system. It is demonstrated that accurate robot and feature locations can be obtained using the proposed technique.
Tran, TH, Ha, QP & Dissanayake, G 1970, 'New wavelet-based,pitch detection method for human-robot voice interface', 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), 2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), IEEE, Sendai, Japan, pp. 527-532.
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Speech activated interface between human and autonomous/semi-autonomous systems requires accurate voice detection and recognition. In this area pitch and end-point detection is of vital importance. This paper presents a new method for pitch detection based on the phase of the continuous wavelet transform. The advantage of the proposed technique is that it can serve not only as an accurate pitch detector, but also can offer an efficient solution to the end-point detection problem. Experimental results are provided for the detection of pitch periods and end points in a neural-network based voice enabled wheelchair system.
Wei, DB, Han, JT, Tieu, AK & Jiang, ZY 1970, 'An Analysis on the Inhomogeneous Microstructure in Crack Healing Area', Key Engineering Materials, 7th Asia-Pacific Symposiumon Engineering Plasticity and Its Applications (AEPA 2004), Trans Tech Publications, Ltd., Shanghai Jiaotong Univ, Shanghai, PEOPLES R CHINA, pp. 1053-1058.
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Zheng, T, Liu, D & Wang, P 1970, 'Priority Based Dynamic Multiple Robot Path Planning', Proceedings of the 2nd International Conference on Autonomous Robots and Agents (ICARA'04), International Conference on Autonomous Robots and Agents, Massey University, New Zealand, Palmerston North, New Zealand, pp. 373-378.
