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OPTIMAL STRAPDOWN ATTITUDE INTEGRATION algorithmS

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1990年第2期13卷 363-369页

作者： IGNAGNI, MB Honeywell Systems and Research Center Minneapolis Minnesota

The paper examines various algorithms for integrating the noncommutivity rate equation arising in the implementation of the attitude reference function of a strapdown inertial navigation system, and derives a class of optimized algorithms for performing this integration. The accuracy characteristics associated with each of the algorithms, when the system is exposed to pure coning motion, as well as to a generalized vibrational environment, are defined. The class of optimized algorithms is shown to minimize the mean error in the correction provided by the algorithm in a generalized vibrational environment. (Author)

关键词： algorithm Performance Strapdown Inertial Navigation System Angular Motion selection algorithm Digital Computers Inertial Sensor

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Four-bar motion generation with elasticity constraints and optimization

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART K-JOURNAL OF MULTI-BODY DYNAMICS 2009年第3期223卷 245-253页

作者： Al-Smadl, Y. M. Russell, K. Sodhi, R. S. AECOM Special Struct Grp New York NY 10005 USA USA Armaments Engn & Technol Ctr Ctr Res Dev & Engn Picatinny Arsenal NJ USA New Jersey Inst Technol Dept Mech Engn Newark NJ 07102 USA

In conventional planar four-bar motion generation, all mechanism links are assumed rigid or non-deforming. Although the assumption of link rigidity in kinematic synthesis may be generally appropriate and often practiced, a statically loaded planar four-bar mechanism will undergo a degree of elastic deflection, particularly the crank and follower links. In this work, a non-linear optimization problem is formulated for planar four-bar motion generation that considers an applied coupler force and corresponding crank static torque, crank transverse deflection, and follower buckling. The output from the non-linear optimization problem - mechanism fixed and moving pivot loci - are input for a search algorithm that down selects a mechanism solution that satisfies transmission angle conditions, Grashof conditions, and a mechanism compactness condition. The final output of the presented method is planar four-bar motion generator that approximates prescribed coupler poses with satisfactory crank deflection and without follower buckling and also satisfies conditions for link rotatability, transmission angle and compactness.

关键词： motion generation coupler force elastic deflection buckling selection algorithm

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Behaviour-based control approach for the trajectory tracking of an underactuated planar capsule robot

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IET CONTROL THEORY AND APPLICATIONS 2015年第2期9卷 163-175页

作者： Huda, M. Nazmul Yu, Hongnian Cang, Shuang Bournemouth Univ Fac Sci & Technol Poole BH12 5BB Dorset England Bournemouth Univ Sch Tourism Poole BH12 5BB Dorset England

A miniature capsule robot (capsubot) - which has no external moving parts whereas a conventional robot has legs and/or wheels - is suitable for in-vivo applications, engineering diagnosis and pipe inspection. This study addresses the trajectory-tracking problem of an underactuated planar capsubot. A combining piecewise and behaviour-based control algorithm is proposed for trajectory tracking. This study also proposes four motion behaviours, four switching behaviours and one stationary behaviour. A selection algorithm for behaviour-based control and rules for inner mass (IM) motion control in all the behaviours are developed. The partial feedback linearisation control is used for low-level IM motion control while the piecewise and behaviour-based control is used for the capsubot trajectory tracking control.

关键词： microrobots trajectory control mobile robots motion control feedback behaviour-based control approach underactuated planar capsule robot miniature capsule robot in-vivo applications engineering diagnosis pipe inspection trajectory-tracking problem behaviour-based control algorithm motion behaviours switching behaviours stationary behaviour selection algorithm inner mass motion control IM motion control partial feedback linearisation control piecewise-based control capsubot trajectory tracking control

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VR-CPES: A Novel Cyber-Physical Education Systems for Interactive VR Services Based on a Mobile Platform

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MOBILE INFORMATION SYSTEMS 2018年第Pt.3期2018卷 8941241.1-8941241.10页

作者： Kim, Hanjin Shin, Heonyeop Kim, Hyeong-su Kim, Won-Tae KOREATECH Univ Dept Comp Sci & Engn Smart CPS Lab Cheonan South Korea

The evolution of virtual reality technology allows users to immerse themselves into virtual environments, providing a new experience that is impossible in the real world. The appearance of cyber-physical systems and the Internet of things makes humans to understand and control the real world in detail. The integration of virtual reality into cyber-physical systems and the Internet of things may induce innovative education services in the near future. In this paper, we propose a novel, a virtual reality-based cyber-physical education system for efficient education in a virtual reality on a mobile platform, called VR-CPES. VR-CPES can integrate the real world into virtual reality using cyber-physical systems technology, especially using digital twin. We extract essential service requirements of VR-CPFS in terms of delay time in the virtual reality service layer. In order to satisfy the requirements of the network layer, we design a new, real-time network technology interworking software, defined as network and time-sensitive network. A gateway function for the interworking is developed to make protocol level transparency. In addition, a path selection algorithm is proposed to make flexible flow between physical things and cyber things. Finally, a simulation study will be conducted to validate the functionalities and performance in terms of packet loss and delay as defined in the requirements.

关键词： virtual reality Cyber-physical systems Platform Mobile Virtual environments Internet of things Delay time Packet loss Legal Services Thing interworking moving platform virtual reality technology selection algorithm Variable reluctance

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Hybrid Discontinuous Galerkin/Finite Volume Method with Subcell Resolution for Shocked Flows

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AIAA JOURNAL 2021年第6期59卷 2027-2044页

作者： Jiang, Zhen-Hua Deng, Xi Xiao, Feng Yan, Chao Yu, Jian Lou, Shuai Beijing Univ Aeronaut & Astronaut Coll Aeronaut Sci & Engn Beijing 100191 Peoples R China Imperial Coll London Dept Aeronaut London SW7 2AZ England Tokyo Inst Technol Dept Mech Engn Meguro Ku 2-12-1 i6-29 Ookayama Tokyo 1528550 Japan

A hybrid discontinuous Galerkin (DG)/finite volume (FV) method under the multistage boundary variation diminishing (BVD) reconstruction paradigm is developed for shocked inviscid and viscous flows. The methodology uses high-order unlimited polynomials and the THINC (which stands for tangent of hyperbola for interface capturing) function as the candidate reconstruction functions to perform FV computation on embedded subcells. The reconstruction scheme on the FV subcells can be designed in a way to keep the resulting approach as compact as the underlying DG method. The reconstruction information based on the modified BVD selection algorithm has been applied as an indicating strategy so that no additional discontinuity indicator is required for the hybrid DG/FV computation. The designed approach has been investigated through the coupling with the explicit and implicit time discretization scheme for both inviscid and viscous flows. Numerical results demonstrate the high-fidelity characteristics of the method by using a much coarser grid to capture both the discontinuity and the smooth flow structure with high resolution.

关键词： Numerical Integration Hypersonic Flows Finite Volume Method selection algorithm Total Variation Diminishing Mach Reflection Mach Number Vortices Euler Equations Conductivity Coefficients

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A Hybrid Intelligent System Framework for the Prediction of Heart Disease Using Machine Learning algorithms

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MOBILE INFORMATION SYSTEMS 2018年第Pt.3期2018卷 3860146.1-3860146.21页

作者： Ul Haq, Amin Li, Jian Ping Memon, Muhammad Hammad Nazir, Shah Sun, Ruinan Univ Elect Sci & Technol China Sch Comp Sci & Engn Chengdu 611731 Sichuan Peoples R China Univ Swabi Dept Comp Sci Khyber Pakhtunkhwa Pakistan

Heart disease is one of the most critical human diseases in the world and affects human life very badly. In heart disease, the heart is unable to push the required amount of blood to other parts of the body. Accurate and on time diagnosis of heart disease is important for heart failure prevention and treatment. The diagnosis of heart disease through traditional medical history has been considered as not reliable in many aspects. To classify the healthy people and people with heart disease, noninvasive-based methods such as machine learning are reliable and efficient. In the proposed study, we developed a machine-learning-based diagnosis system for heart disease prediction by using heart disease dataset. We used seven popular machine learning algorithms, three feature selection algorithms, the cross-validation method, and seven classifiers performance evaluation metrics such as classification accuracy, specificity, sensitivity, Matthews' correlation coefficient, and execution time. The proposed system can easily identify and classify people with heart disease from healthy people. Additionally, receiver optimistic curves and area under the curves for each classifier was computed. We have discussed all of the classifiers, feature selection algorithms, preprocessing methods, validation method, and classifiers performance evaluation metrics used in this paper. The performance of the proposed system has been validated on full features and on a reduced set of features. The features reduction has an impact on classifiers performance in terms of accuracy and execution time of classifiers. The proposed machine-learning-based decision support system will assist the doctors to diagnosis heart patients efficiently.

关键词： Heart Diseases hybrid intelligent system Machine learning algorithms Persons selection algorithm Performance Evaluation execution time diagnostic system Classifiers

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Non-line-of-sight identification via phase difference statistics across two-antenna elements

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IET COMMUNICATIONS 2011年第13期5卷 1814-1822页

作者： Xu, W. Wang, Z. Zekavat, S. A. (Reza) Michigan Tech Univ Dept Elect & Comp Engn Houghton MI 49931 USA

This study proposes and investigates the performance of a new non-line-of-sight (NLOS) identification technique for multiple antenna systems that is based on the phase difference across two antenna elements. In order to avoid any confusion in the position location process, NLOS identification techniques should be implemented in the localisation systems. A phase wrapping selection algorithm is proposed to calculate the phase difference variance across two-antenna elements. A theoretical relationship is maintained between the phase difference variance and the Rician K-factor. The proposed K estimator requires an uncorrelated phase across antenna elements. The validity of this assumption is verified via channel modelling simulations. Then, a hypothesis test on the K-factor is formed to identify NLOS situations. The prior distributions of K-factor under line-of-sight (LOS) and NLOS conditions, and the K-factor threshold that are used to distinguish LOS and NLOS situation are derived. The impact of shadowing on the performance of the proposed NLOS identification method is studied. The performance of the proposed phase difference K estimator technique is compared with the envelope-based K estimator.

关键词： Hypothesis testing ANTENNA SYSTEM antenna element phase difference selection algorithm k factors Authentication Shadowing (Histology)

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Efficient floristic inventory for the assessment of tropical tree diversity: A comparative test of four alternative approaches

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FOREST ECOLOGY AND MANAGEMENT 2006年第1-3期237卷 564-573页

作者： Gordon, James E. Newton, Adrian C. Fairchild Trop Garden Ctr Trop Plant Conservat Miami FL 33156 USA Bournemouth Univ Sch Conservat Sci Poole BH12 5BB Dorset England

Biodiversity inventory as a tool for guiding conservation planning at a local scale is under used, especially in tropical countries where technical capacity is often limited. Here four inventory protocols (one ad hoc, one fixed count and two fixed area methods) are tested for their efficiency and statistical robustness when applied to the woody floras of a Mexican seasonally dry tropical forest. They are tested for their ability to distinguish between sites not only by number of species (richness), but also by number of threatened species, and finally in their application to complementary reserve selection exercises. Whilst the ad hoc method is shown to have the advantage of high efficiency and is technically undemanding, where possible the statistically more robust fixed count or fixed area methodologies are recommended. However, the much used fixed area method of Gentry [Gentry, A.H., 1982. Patterns of neotropical plant species diversity. Evol. Biol. 15, 1-84] that uses 2 m x 50 m plots is shown to be inefficient. Only when comparison with other previously published assessments is a priority should the 2 m x 50 m fixed area method be considered, and then efficiency may be increased by widening the plots and distinguishing between those stems that fall within a notional 2 m plot and those outside of it. Both prioritisation by number of species and complementarity analysis, using the 'greedy' algorithm, are shown to be sensitive to choice of inventory protocol, suggesting that consideration is given to how species lists are obtained in reserve selection exercises. (c) 2006 Elsevier B.V. All rights reserved.

关键词： biodiversity assessment rapid botanical assessment reserve selection tropical dry forest selection algorithm

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Design of deep stall protection for the C-17A

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1997年第4期20卷 760-767页

作者： Iloputaife, OI McDonnell Douglas Aerospace Long Beach California 90807-4418

The design of the C-17 angle-of-attack limiter system is presented. The C-17, because of its T-tail, has a locked-in deep stall potential in some aft center of gravity configurations. The angle of-attack system uses alpha measurements from three pairs of vanes for precise angle-of-attack control and to prevent excursion into the deep stall region. The vanes, because of their locations, are sensitive to sideslip angle excursions in varying degrees, therefore, requiring sideslip angle information for proper failure monitoring. A method of synthesizing sideslip and angle of attack using the information from the vanes was developed. With the synthesized angle of attack and sideslip, it was possible to provide a minimum of fail-operational-fail-operational capability with tight failure tolerance, After over 2000 stall tests and assaults to alpha limit, the pilot community has gained the confidence that the system will protect the C-17 from entering the locked in deep stall region.

关键词： Angle of Attack Sideslip Angle Air Vehicle Test Pilots Stick Pusher Pitching Moment Aircraft Roll Calibrated Airspeed Elevator selection algorithm

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Quickly Finding the Smallest Numerical Subset with Its Sum above a Threshold

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WIRELESS PERSONAL COMMUNICATIONS 2018年第1期103卷 427-436页

作者： Xu, Libo Pang, Chaoyi Li, Xingsen Zhejiang Univ NIT Sino Aus Joint Ctr Social Comp & Data Management Ningbo Zhejiang Peoples R China Hebei Univ Econ & Business Shijiazhuang Hebei Peoples R China

Given a set of numerical values and a threshold, finding the minimum subset from the set such that its sum is not less than the threshold value, is termed as SelectSum problem which is widely applicable in data compression and image processing. In this article, we provide two new linear-time algorithms for the problem. Different from the current approaches that directly calling the selection algorithms for partitioning on median elements, our proposed algorithms embed the selection process and use cheap pivot elements for partitioning. The experimental tests indicate these two new algorithms are significant faster than the current existing algorithms on larger data sets.

关键词： selection algorithm SelectSum algorithm Data compression Data sorting

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