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High-torque density integrated electro-mechanical flight actuators

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2002年第1期38卷 174-182页

作者： Lyshevski, SE Skormin, VA Colgren, RD Purdue Univ Dept Elect & Comp Engn Indianapolis IN 46202 USA SUNY Binghamton Dept Elect Engn Binghamton NY 13902 USA Lockheed Martin Aeronaut Co Palmdale CA USA

Electro-mechanical flight actuators (EMFAs) are core flight-critical vehicle components. Fly-by-wire or fly-by-light control of EMFAs Is performed by flight management systems (flight, mission, propulsion, and integrated controls that manage any combination of specific flight, mission, and propulsion functions). Reported here are novel results in the analysis of EMFAs with permanent-magnet synchronous motors, with particular interest in the application of brushless high-torque density motors which have superior characteristics compared with other state-of-the-art motor technologies. It is shown that due to nonlinearities and bounds, new control algorithms must be developed and implemented to achieve a spectrum of performance and requirements for EMFAs. A number of important issues in control, analysis, model development, integration, and verification are studied. Tracking control algorithms are synthesized, stability studied, and novel analysis results are reported. Advanced computer-aided engineering software tools and emerging simulation-based design environments are used to guarantee high fidelity modeling and analysis within data Intensive simulation. Proof-of-concept demonstration testbeds for the design of advanced EMFAs and their components are developed, and EMFA imitator performance thoroughly studied. Verification of the concepts reported are formed and documented. Precise tracking, disturbance attenuation, accuracy, stability, robustness, and excellent acceleration capabilities are reported. A demonstration is performed to substantiate the theoretical analyses to add credence to Its applicability as an approach and method that the designer of future EMFAs can use to design a new class of actuators for aircraft flight control surfaces.

关键词： Lyapunov methods aerospace computing aircraft control computer aided engineering control system CAD eigenvalues and eigenfunctions electromagnetic actuators nonlinear control systems permanent magnet motors pole assignment servomechanisms synchronous mot pole assignment Aircraft control Servomechanism New classes Lyapunov methods computer algorithms control system CAD aerospace computing Permanent magnet synchronous machines Nonlinear control systems Eigenfunctions high torque electromagnetic actuators actuators

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Design and modeling of a flexible test bed for use in control system analysis and verification

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MECHATRONICS 2002年第7期12卷 891-904页

作者： Mason, G Pongpunwattana, A Berg, M Seattle Univ Dept Engn Mech Seattle WA 98122 USA Univ Washington Dept Mech Engn Seattle WA 98195 USA

This paper describes a test bed specifically designed for studying the effects of nonlinear friction, backlash, and drive train flexibility on structurally flexible electro-mechanical systems, and for developing control algorithms that will compensate for nonlinear friction, backlash, and drive train flexibility in structurally flexible electro-mechanical systems. The test bed has a modular and adjustable design. Friction, backlash, and flexibility can all be varied or disabled. A mathematical model of the dynamics of the test bed is also described. This model includes stiction, Coulomb friction, backlash and drive train, and link flexibility. The model is verified via comparisons of model-predicted and experimental responses. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： Control system analysis flexibility test test bed Electro-Mechanical Systems Mechanical drive drive train computer algorithms Verification Modeling

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Setting up alternating least squares and iterative majorization algorithms for solving various matrix optimization problems

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COMPUTATIONAL STATISTICS & DATA ANALYSIS 2002年第1期41卷 157-170页

作者： Kiers, HAL Univ Groningen Heymans Inst DPMG NL-9712 TS Groningen Netherlands

A general procedure is described for setting up monotonically convergent algorithms to solve some general matrix optimization problems, if desired, subject to a wide variety of constraints. An overview is given of a number of ready-made building blocks (derived in earlier publications) from which concrete algorithms are set-up with little effort. These algorithms are based on alternating least squares (block relaxation) and iterative majorization. It is demonstrated how the construction of an algorithm for a particular problem that falls in one of the classes of optimization problems under study, reduces to a simple combination of tools. Also, a procedure is reviewed for setting up a weighted least squares algorithm for any problem for which an unweighted least squares solution is available. All procedures are illustrated by means of examples. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： LEAST squares computer algorithms MATHEMATICAL optimization

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Numerically controlled oscillators with hybrid function generators

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IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL 2002年第7期49卷 995-1004页

作者： Janiszewski, I Hoppe, B Meuth, H Univ Appl Sci D-64295 Darmstadt Germany

Numerically controlled oscillators (NCOs), with a hybrid scheme of both look-up tables (LUT) and coordinate transformation digital computer (CORDIC) algorithms for a hardware efficient, high performance sine/cosine function generation are investigated. This scheme combines fast access and power efficiency of reasonably sized LUTs, and arbitrary precision obtainable from a rigorous iteration algorithm. Systematic studies using hardware description language (HDL) models and synthesis lead to optimum LUT/CORDIC ratios, which minimize power consumption and silicon area for a given operating clock frequency. First order error models are presented as guidelines for choosing internal NCO parameters. The NCO accuracy is tested with HDL simulations for all algorithmic states to limit output errors to 1 least significant bit (LSB) and by spectra derived from discrete Fourier transform (DFT) for typical frequency inputs f, resulting in a signal to noise ratio (SNR) of better than 100 dB for an amplitude word length AW of 16 Bit. Two benchmark designs were adopted for the two clock frequencies 200 MHz and 20 MHz, as "high" and "moderate" performance, respectively. The NCO models are synthesized in a 0.35 mum CMOS standard cell target technology and optimized to actually achieve after layout maximum clock frequencies exceeding 310 MHz, i.e., signal frequencies of up to 100 MHz.

关键词： FREQUENCY synthesizers computer algorithms CRYSTAL oscillators

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Adaptive boundary control of an axially moving string system

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JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME 2002年第3期124卷 435-440页

作者： Fung, RF Wu, JW Lu, PY Natl Kaohsiung First Univ Sci & Technol Dept Mech & Automat Engn Kaohsiung 824 Taiwan

This paper proposes an adaptive boundary control to an axially moving string system, which couples with a mass-damper-spring (MDS) controller at its right-hand-side (RHS) boundary. Unknown parameters appearing in the system equation are assumed constant and estimated on-line by using adaptation laws. The adaptive computed-torque control algorithm applied to robot manipulators of lumped systems is extended to design the adaptive boundary controller for the coupling system. It is found that the control force and update laws depend only on the displacement, velocity and slope of the string at the RHS boundary. Lyapunov stability guarantees the convergence of the tracking error to zero. Finally, the performance of the proposed controller is demonstrated by numerical simulations.

关键词： binding force Boundary axial movement coupled system ATOMIC DISPLACEMENTS System of equations Controllers boundary layer Cosmic strings Self tuning computer algorithms

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Integrated micro- and miniscale electromechanical systems with permanent-magnet servo-motors and VLSI drivers-controllers

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MECHATRONICS 2002年第9-10期12卷 1115-1131页

作者： Lyshevski, SE Nazarov, A Boggs, J Indiana Univ Purdue Univ Dept Elect & Comp Engn Indianapolis IN 46202 USA

The current trends in development and deployment of advanced micro- and miniscale electromechanical systems (MEMS) have facilitated the unified fundamental, applied, and experimental research activities in the analysis and design of state-of-the-art motion devices (rotational and translational electromechanical motion devices), integrated circuits (ICs), and controllers. The objectives of this paper are to design, develop, and compare different control algorithms for high-performance MEMS with permanent-magnet rotational servo-motors controlled by ICs (VLSI driver-controller is fabricated using CMOS technology). The problems to be solved are very challenging because a number of long-standing issues in design, hardware integration, control, nonlinear analysis, and robustness have to be solved. The major emphases of this paper are the analysis and design of robust servo-systems, as well as the comparison of the dynamic performance of closed-loop MEMS with different control algorithms. We. synthesize, verify, and test proportional-integral, integral with state feedback extension, relay, and sliding mode controllers. It is illustrated that the sliding mode control laws drive the states and tracking error to the switching surface and maintain (keep) the states and tracking error within this nonlinear switching surface in spite of different references, disturbances, parameter variations, and uncertainties. That is, robust tracking, desired accuracy, and disturbance attenuation are achieved. We report the experimental setup which was built to perform the advanced studies of high-performance MEMS. The testbed was built to integrate permanent-magnet microscale servo-motor and ICs (driver-controller). (C) 2002 Published by Elsevier Science Ltd.

关键词： Permanent magnets Microelectromechanical systems CMOS technology Servo Device Component NONLINEAR ANALYSIS Very large scale integration dynamic characteristics switching surface Integrated circuits Electromechanical systems computer algorithms

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Transient improvement of variable structure controlled systems via multi-model switching control

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME 2002年第2期124卷 321-326页

作者： Corradini, ML Orlando, G Univ Lecce Dipartimento Ingn Innovazione I-73100 Lecce Italy Univ Ancona Dipartimento Elettron & Automat I-60131 Ancona Italy

A solution is presented in this note to the problem of improving the transient response of a MIMO nonlinear system driven by a VSC law, in the presence of large plant uncertainties. The proposed control scheme is given in terms of a supervisor and of a deterministic time-varying compensator, built using sliding-mode control and assuming a finite number of possible different configurations. The task of the supervisor is that of guiding the scanning among the elements of the family, according to a suitably defined experimental test. The proposed approach noticeably improves the performances of sliding-mode control in the presence of large plant uncertain ties, and has the substantial advantage of a great simplicity of design and implementation. Moreover, even in case of a large number of configurations constituting the stabilizing family, it has been shown to be able to attain the stabilizing controller in an arbitrarily small time interval. Another appealing feature of the paper consists in the inclusion of an intelligent adaptation scheme in the control algorithm.

关键词： Time intervals Note Taking Supervisors Stabilising Standing Orders MIMO nonlinear systems Variable structure Variable structure systems Uncertainty computer algorithms family

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Extracting geometric attributes directly from scanned data sets for feature recognition

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INTERNATIONAL JOURNAL OF computer INTEGRATED MANUFACTURING 2002年第1期15卷 50-61页

作者： Jun, YT Raja, VH Korea Inst Sci & Technol CAD CAM Res Ctr Seoul 136792 South Korea Univ Warwick Int Mfg Ctr Warwick Mfg Grp Coventry CV4 7AL W Midlands England

Reverse engineering (RE) is the process of digitally capturing physical entities of an existing part from its scanned data. A novel methodology is proposed for reconstruction of CAD models by recognizing prismatic features from a data set of three-dimensional scanned points, which utilizes the concepts of artificial neural networks (ANNs). Four geometric attributes, such as chain code, convex/concave, circular/rectangular, and open/closed attribute, are extracted from a scanned point set first, and then they are presented to the ANN module for feature recognition. Each generic feature in the feature library is uniquely described by those geometric attributes. Identifying each feature requires the determination of these attributes beforehand. Once these attributes are determined, a segmented point set may be uniquely identified as a valid feature through the ANN module. Since feature recognition is carried out based on these attributes, this paper focuses on algorithms for determining these attributes directly from a scanned point set. The system validation and sample results are also discussed.

关键词： computer algorithms REVERSE engineering

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Efficient randomized algorithms for input-queued switch scheduling

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IEEE MICRO 2002年第1期22卷 10-18页

作者： Shah, D Giaccone, P Prabhakar, B Stanford Univ Dept Comp Sci Stanford CA 94305 USA Politecn Torino Dept Elect Turin Italy

High-performance schedulers for input-queued (IQ) switches must find, for each time slot, a good matching between inputs and outputs to transfer packets. At high line rates or for large switches, finding good matchings is complicated. A suite of randomized algorithms for switch scheduling provides performance comparable to that of well-known, effective matching algorithms, yet is simple to implement.

关键词： computer algorithms STOCHASTIC processes SCHEDULING MATHEMATICAL models TESTING SWITCHING circuits

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Automated natural spoken dialog

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computer 2002年第4期35卷 51-+页

作者： Gorin, AL Abella, A Alonso, T Riccardi, G Wright, JH AT&T Labs Res Speech Res Dept Murray Hill NJ 07974 USA

The next generation of voice-based interface technology will enable easy-to-use automation of new and existing communication services, making human-machine interaction more natural.

关键词： PROGRAMMING languages (Electronic computers) computer algorithms

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