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DEPLOYMENT RETRIEVAL CONTROL OF TETHERED SUBSATELLITE THROUGH AN OPTIMAL PATH

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1994年第6期17卷 1292-1298页

作者： FUJII, HA ANAZAWA, S Tokyo Metropolitan Institute of Technology Hino Tokyo 191 Japan

Development of a feedback control law to follow an optimal path is presented concerning the deployment/retrieval phase of a subsatellite connected to the Shuttle through a tether. The optimal path to be tracked is obtained numerically by solving a two-point boundary-value problem with inequality constraints on tether tension that is the control force, with fixed boundary conditions, and with an unspecified terminal time. The feedback control algorithm is designed using a Lyapunov function to asymptotically reduce the deviation of the actual trajectory from the optimal path. The Lyapunov function is defined to be positive definite and to be zero when the trajectory coincides simultaneously with the optimal path. The present method of control is simulated numerically, and the results show excellent controlled response of the tethered subsatellite system. A comparison of the present approach with the neighboring optimum feedback control is also presented and shows the superior performance of the tracking-type control using the Lyapunov function for large initial variations from the optimal path.

关键词： Feedback Control Control Algorithm Boundary Value Problems Optimal Control Numerical Simulation distributed parameter system Conjugate Gradient Method Numerical Analysis Tethered Satellite system Artificial Gravity

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ELASTODYNAMIC CHARACTERISTICS OF HOLLOW CANTILEVER BEAMS CONTAINING AN ELECTRORHEOLOGICAL FLUID - EXPERIMENTAL RESULTS

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AIAA JOURNAL 1994年第2期32卷 438-440页

作者： CHOI, SB PARK, YK AGCY DEF DEV DIV SUSPENS DEV & DYNAM ANALTAEJON 305600SOUTH KOREA

The vibration control of flexible structures with variable disturbances in different frequencies becomes more and more important because of the demand for higher positional accuracy and more stable manipulation. This paper reports on a proof-of-concept experimental investigation focused on evaluating the elastodynamic characteristics of hollow cantilever beams filed with a hydrous-based ER fluid consisting of cornstarch and silicone oil. The beams are considered to be uniform viscoelastic materials and modeled as a viscously damped harmonic oscillator. Electric field dependent natural frequencies, loss factors, and complex moduli are evaluated and compared among three different beams: two types of different volume fraction of the ER fluid and one type of different particle concentration of the ER fluid by weight.

关键词： Smart Materials and Structures Cantilever Beam Resonant Frequencies Influence Coefficients Active Vibration Control Viscoelastic Material Rockets distributed parameter system Logarithmic Decrement Flexible Structures

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BOUNDARY DIFFUSION-CONTROLLED CREEP MODEL IN NANOCRYSTALS

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AIAA JOURNAL 1994年第2期32卷 436-438页

作者： KANIARIS, KP LYRINTZIS, CS SAN DIEGO STATE UNIV DEPT AEROSP ENGN & ENGN MECHSAN DIEGOCA 92182

Nanocrystalline materials (NCMs) by definition are single or multiphase polycrystals with a crystal size on the order of 1-10nm. NCMs seem to permit the alloying of components, which results in alloys with properties attractive to the aerospace industry. The research around nanocrystals adds a few more difficulties. There is a smaller size and very random arrangement of atoms. Such uncontrollable characteristics are related to the viscosity model by Herring. The focus of this paper is to improve the creep model accepted today along with its diffusivity parameters. By using both the Coble and Herring models and Coffey's assumptions for grain boundary sources and by adjusting the vacancy concentration gradient one can derive a more accurate nanocrystalline creep equation.

关键词： Creep Nanocrystals Smart Materials and Structures Harmonic Oscillator Stress Distribution Cantilever Beam Vortices Diffusion Coefficient Active Vibration Control distributed parameter system

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INTERNAL MODEL CONTROL FOR SINGLE TUBULAR HEAT-EXCHANGER system

INTERNAL MODEL CONTROL FOR SINGLE TUBULAR HEAT-EXCHANGER SYS...

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20th International Conference on Industrial Electronics Control and Instrumentation

作者： ABE, N SEKI, K KANOH, H MEIJI UNIV DEPT PRECIS ENGN KAWASAKI KANAGAWA 214 JAPAN

ISBN: (纸本)0780313283

Internal Model Control (IMC) was implemented for the temperature control of a single tubular heat exchanger system. The experimental heat exchanger system was very simple structure, however, the characteristics was regarded as a distributed parameter system. Since IMC used the system model, it was necessary to identify the parameters precisely. The step response and the usual frequency response method and least square method were used for 1st order plus time delay, 2nd order system and for fitting the coefficient of partial differential equation, respectively. In the laboratory experiment, it was clear that: 1) Since IMC structure includes PI controller, the performance of IMC with superior to PI control. 2) The only one tuning filtering parameter of IMC controller effected the sensitivity and robustness. 3) Since IMC controller was constructed from system model, it is very important to set up the plant model and identifications.

关键词： INTERNAL MODEL CONTROL PROCESS CONTROL HEAT EXCHANGER system distributed parameter system

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system Identification of an Adsorption Process Using Neural Networks

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IFAC Proceedings Volumes 1994年第2期27卷 53-58页

作者： A. Bulsari J. Lewandowski S. Palosaari Department of Chemical Technology Lappeenranta University of Technology Box 20 53851 Lappeenranta Finland

The aim of this work is to investigate the feasibility of the use of neural networks for system identification of the dynamics of a distributed parameter system, an adsorption column for wastewater treatment of water containing toxic chemicals. system identification of this process is done from simulated data. Feed-forward neural networks have been used for most of the work reported here. The inputs to the networks include the state of the column at a given point in time and the system input, the velocity. The network predicts the change in the state over a period of time based on these inputs. Networks of various sizes were trained using data from four simulation runs, and were then tested on data which was not used for training. The network with the configuration (11,6,10) gave the best results in absence of added noise. Recurrent networks were found to be capable of simulating the whole operation of the column from an initial state of zero concentrations throughout the column, and thus predicting the complete breakthrough curves.

关键词： system identification adsorption distributed parameter system breakthrough curves process dynamics

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Quasi-static control of cooperative multiple two-link flexible manipulators whose second links are on a straight line

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IFAC Proceedings Volumes 1994年第14期27卷 1011-1016页

作者： F. Matsuno N. Asai M. Hatayama Y. Sakawa Kobe University Department of Computer and Systems Engineering Nada Kobe 657 Japan Kawasaki Heavy Ind. Ltd. Akashi 660 Japan Osaka University Department of Systems Engineering Toyonaka Osaka 560 Japan

In this paper, a dynamic model and a control architecture are developed for the closed chain motion of multiple two-link flexible manipulators holding a common rigid object in a horizontal workspace. We derive dynamic equations of joint angles of two manipulators, vibrations of the flexible links, and contact force by means of Hamilton’s principle. On the basis of some assumptions we derive the quasi-static equations and design the cooperative controller of two flexible manipulators. A set of experiments for the cooperative control of two flexible manipulators using a force sensor has been carried out. Several experimental results are shown.

关键词： Cooperation Flexible manipulator distributed parameter system Quasi-static equation Pseudovelocity

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SHAPING OF system RESPONSES WITH MINIMAX OPTIMIZATION IN THE TIME DOMAIN

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1993年第1期16卷 40-46页

作者： OHTSUKA, T FUJII, H Tokyo Metropolitan Institute of Technology Tokyo 191 Japan

A minimax problem is introduced for the terminal control of a generic dynamical system without disturbances. The maximum magnitude of the weighted output of the system is minimized over a finite interval by the control input of a prescribed class. Such important characteristics of the controlled system appear explicitly in the proposed problem as the maximum magnitude and settling property of the output. Two numerical examples are shown to illustrate the problem. A slewing experiment is also presented to demonstrate the application of the minimax optimal control.

关键词： Transversality Condition Control system Design Terminal Control distributed parameter system Bernoulli Euler Beams Vibration Suppression Feedback Control system Large Angle Maneuver Mathematical Models Conjugate Gradient Algorithm

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FEEDBACK GAIN SENSITIVITIES OF CLOSED-LOOP MODAL parameterS OF CONTROLLED STRUCTURES

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1993年第5期16卷 892-898页

作者： FABUNMI, JA AEDAR Corp. Landover MD

Computer algebra (MACSYMA) has been used to derive the characteristic polynomials that determine the closed-loop frequencies and damping coefficients of output-feedback controlled structures. These expressions show explicitly bow the locations of the actuator/sensor pairs and the displacement and velocity feedback gains influence the frequencies and damping parameters of the dosed-loop system modes. For lightly coupled modes, simple relations are obtained between the modal parameters and the coordinates of the sensor/actuator pairs as well as the displacement and velocity feedback gains. Using the example of a cantilevered uniform beam controlled by a single sensor/actuator pair, numerical results are used to illustrate the sensitivity of the closed-loop modal parameters to the placement of the sensor/actuator pair as well as the feedback gains. Such results help answer questions about optimal placement of sensor/actuator pairs for the active control of a flexible structure.

关键词： distributed parameter system Sensitivity Analysis Dynamic Substructuring Feedback Control Active Vibration Control Euler Bernoulli Beams Flexible Structures Finite Element Method Dynamic Response Cantilever Beam

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INFINITE-DIMENSIONAL VOLTERRA-STIELTJES EVOLUTION-EQUATIONS AND RELATED OPTIMAL-CONTROL PROBLEMS

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SIAM JOURNAL ON CONTROL AND OPTIMIZATION 1993年第3期31卷 539-568页

作者： YONG, JM Fudan Univ Shanghai China

Due to impulse control problems, a controlled Volterra-Stieltjes system in some Banach space is studied. In the system, the vector measure appearing in the Stieltjes-type integral (called Young integral here) is taken as a part of control action. In this paper, a general theory for infinite-dimensional Volterra-Stieltjes evolution equations is presented, and, for an optimal control problem governed by such type controlled system with a general endpoint constraint, a Pontryagin-type maximum principle is proved.

关键词： YOUNG INTEGRAL VOLTERRA-STIELTJES INTEGRAL EQUATION distributed parameter system MEASURE CONTROL MAXIMUM PRINCIPLE OPTIMAL CONTROL

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MINIMUM-TIME PULSE RESPONSE BASED CONTROL OF FLEXIBLE STRUCTURES

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1993年第5期16卷 874-881页

作者： BENNIGHOF, JK CHANG, SHM SUBRAMANIAM, M University of Texas at Austin Austin Texas 78712

This paper presents the pulse response based control method for minimum time control of structures. An explicit model of a structure is not needed for this method, because the structure is represented in terms of its measured response to pulses in control inputs. Minimum time control problem are solved by finding the minimal number of time steps for which a control history exists that consists of a train of pulses, satisfies input bounds, and results in desired outputs at the end of the control task. There is no modal truncation in the pulse response representation of the response, because all modes contribute to the pulse response data. The precision with which the final state of the system can be specified using pulse response based control is limited only by the observability of the system with the given set of outputs. A special algorithm for solving the numerical optimization problem arising in pulse response based control is presented, and the effect of measurement noise on the accuracy of the final predicted outputs is investigated. A numerical example demonstrates the effectiveness of pulse response based control and the algorithm used to implement it. The pulse response based control method is applied to linear problems in this paper.

关键词： distributed parameter system Flexible Structures Numerical Optimization Flexible Spacecrafts Quadratic Programming Bang Bang Control Singular Value Decomposition Boundary Value Problems Vibration Suppression Flexural Rigidity

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