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Indirect robust adaptive fault-tolerant control for attitude tracking of spacecraft

JOURNAL OF GUIDANCE control AND DYNAMICS 2008年第5期31卷 1456-1463页

作者： Cai, Wenchuan Liao, X. H. Song, Y. D. N Carolina Agr & Tech State Univ Ctr Cooperat Syst Greensboro NC 27411 USA Volvo N Amer Inc Greensboro NC 27455 USA N Carolina Agr & Tech State Univ Dept Elect & Comp Engn Greensboro NC 27411 USA Natl Inst Aerosp Hampton VA 23666 USA

Reliable and cost-effective control of spacecraft should account for modeling uncertainties, unexpected disturbances,, subsystem failures, and limited resources simultaneously. This paper presents an indirect (nonregressor-based) approach to attitude tracking control of spacecraft. It is shown that the control algorithms developed are not only robust against external disturbances and adaptive to unknown and time-varying mass/inertia properties, but also able to accommodate actuator failures under limited thrusts. All are achieved with inexpensive online computations (a feature of practical importance in reducing the usage of onboard resources in terms of computing power and memory size). Furthermore, this method is user/designer friendly in that it does not involve a time-consuming design procedure and demands little redesigning or reprogramming during vehicle operation. The benefits of the proposed control method are analytically authenticated and also validated via simulation study.

关键词： Attitude Tracking Rigid Spacecraft Actuators control algorithm Onboard Computing Attitude Dynamics Adaptive control algorithm Variable Structure control Quaternions Numerical Simulation

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Particle swarm optimization used as a control algorithm for adaptive PMD compensation

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IEEE PHOTONICS TECHNOLOGY LETTERS 2005年第1期17卷 85-87页

作者： Zhang, XG Zheng, Y Shen, Y Zhang, JZ Yang, BJ Beijing Univ Posts & Telecommun Sch Sci Dept Phys Beijing 100876 Peoples R China Minist Educ Key Lab Opt Commun & Lightwave Technol Beijing 100876 Peoples R China

We introduce particle swarm optimization (PSO) into adaptive polarization-mode dispersion (PMD) compensation in a 40-Gb/s optical time-division-multiplexing communication system. In the searching process for automatic PMD compensation, the PSO algorithm has the merits of rapid convergence to the global optimum, without being trapped in local suboptima, and good robustness to noise. In this letter, we describe how to implement PSO as a component of a control algorithm in adaptive PMD compensation. Performance comparisons between global and local versions of PSO were carried out theoretically and experimentally. We also demonstrate that a time-varying PMD can be successfully tracked using the PSO technique.

关键词： adaptive compensation control algorithm particle swarm optimization (PSO) polarization-mode dispersion (PMD)

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Semi-active friction dampers for seismic control of structures

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SMART STRUCTURES AND SYSTEMS 2008年第4期4卷 493-515页

作者： Kori, Jagadish G. Jangid, R. S. Indian Inst Technol Dept Civil Engn Bombay 400076 Maharashtra India

Semi-active control systems have attracted a great deal of attention in recent years because these systems can operate on battery power alone, proving advantageous during seismic events when the main power source of the structure may likely fail. The behavior of semi-active devices is often highly non-linear and requires suitable and efficient control algorithm. This paper presents the comparative study and performance of variable semi-active friction dampers by using recently proposed predictive control law with direct output feedback. In this control law, the variable slip force of semi-active variable friction damper is kept slightly lower than the critical friction force, which allows the damper to remain in the slip state during an earthquake, resulting in improved energy dissipation capability. This control algorithm is able to produce a continuous and smooth slip forces for a variable friction damper. The numerical examples include a structure controlled with multiple variable semi-active friction dampers and with multiple passive friction dampers. A parameter, gain multiplier defined as the ratio of damper force to critical damper control force, is investigated under four different real earthquake ground motions, which plays an important role in the present control algorithm of the damper. The numerically evaluated optimum parametric value is considered for the analysis of the structure with dampers. The numerical results of the variable friction dampers show better performance over the passive dampers in reducing the seismic response of structures.

关键词： structural control semi-active control variable friction damper earthquake control algorithm

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IMPROVEMENT OF THE PROTOTYPE algorithm OF HUMAN SIMULATED INTELLIGENT control

IMPROVEMENT OF THE PROTOTYPE ALGORITHM OF HUMAN SIMULATED IN...

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2008 International Conference on Machine Learning and Cybernetics(2008机器学习与控制论国际会议)

作者： PEI-JIN WANG School of Computer Science and Technology Yantai University Yantai China 264005

The prototype algorithm of Human Simulated Intelligent control leads to the overshoot easily, it can not simulate human control Strategies completely. The modified algorithm of HSIC which is called Human-Like Intelligent control is pointed out in this paper, it divides control process into three stages: initial stage, adjusting stage and eliminating disturbance stage. The different control algorithms will be used in different stage, the control method do its best to simulate human control intelligences more nearly. The test results are given , it proves that the experimental result of the prototype algorithm is relatively stable but oscillating, the experimental result of the modified algorithm is better than the prototype algorithm, there is a consistency among stability, fast response and the best accuracy. The HLIC can be used in the process control.

关键词： Intelligent control Human Simulated Intelligent control control algorithm

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SCALAR control STRUCTURE OF AN ASYNCRONOUS MOTOR AT MAXIMUM TORQUE

SCALAR CONTROL STRUCTURE OF AN ASYNCRONOUS MOTOR AT MAXIMUM ...

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19th International Symposium of the Danube-Adria-Association-for-Automation-and-Manufacturing

作者： Chioncel, Cristian Chioncel, Petru Gillich, Nicoleta

ISBN: (纸本)9783901509681

This paper presents a scalar control structure for a asynchronous motor at maximum torque. Voltage and frequency changes in steps until it reaches the final value based on a computing block. The final values for the request voltage and the frequency realised by the control scheme with one, two controller's ore just implementing the computing blocks, are obtained though solving algebraic systems and simulation in transient operating system, by solving differential equations, in an software based on the "Maple" module.

关键词： asynchronous motor - ASM control algorithm

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Inspection Planning control of Laser Guided Measurement Robot

Inspection Planning Control of Laser Guided Measurement Robo...

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7th World Congress on Intelligent control and Automation

作者： Liu, Wanli Qu, Xinghua Ouyang, Jianfei Yan, Yonggang Tianjin Univ State Key Lab Precis Measuring Technol & Instrume Tianjin 300072 Peoples R China Univ Henan Polytech Inst Precis Engn Henan 454000 Peoples R China

ISBN: (纸本)9781424421138

Laser tracking system (LTS) is a portable 3D large size coordinate measuring machines (CMM), it measures 3D coordinates with laser beam by following a spherically mounted retro-reflector (SMR) with the advantages of broad range, high speed and high accuracy. However, the current inspecting task of LTS is performed manually to move SMR along the different position on the surface of a given part and measured with the trial-and-error approach. In order to perform LTS more efficiently and automatically, this paper has developed a laser guided measurement robot (LGMR) based on a new theory "laser beam moving and SMR tracking" instead of the traditional method "SNM moving and laser beam tracking". A systematic control algorithm of generating optimal inspection planning based on CAD-directed model is proposed for LGMR to inspect free-form surfaces. The control algorithm not only generates the movement orientation, position and optimal distance for LGMR, but also a consistent and efficient inspection process that can avoid the unnecessary trials in manual operations and reduce inaccuracy and inconsistency due to different operators. The experiment result has demonstrated that the inspection planning control algorithm can be integrated to the LGMR and generated automated scanning process under automaticity and accuracy constraints.

关键词： Laser guided Measurement robot Inspection planning control algorithm

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A new-style dynamic var compensation control strategy

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3rd International Conference on Electric Utility Deregulation, Restructuring and Power Technologies

作者： Gong, Jinxia Lu, Jingjing Xie, Da Zhang, Yanchi Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China

ISBN: (纸本)9787564112493

A new dynamic reactive power compensation technique for dynamic var compensator is presented. This paper presents the DC capacitor voltage control strategy, the loss current variation control algorithm and a new reactive current calculating method. And the desired compensating current is compared with the measurement of output current in the hysteretic current feedback-loop. Based on the analysis, a newstyle dynamic var compensation control strategy is realized. It also analyzes the relationship between DC capacitor voltage variation characteristic and the active and reactive power flow between AC and DC sides. A novel dynamic var compensation prototype is developed. The experimental waveforms of the prototype show that this control algorithm has the expected compensating performance, demonstrating the validity of the design scheme proposed in this article.

关键词： control algorithm DC voltage control dynamic var compensation loss current reactive current simulation

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Experimental Evaluation of an Adaptive PI Rate controller for Congestion control

Experimental Evaluation of an Adaptive PI Rate Controller fo...

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IEEE International Conference on System, Man, and Cybernetic

作者： Yu, Li Ma, Maode Tianjin Univ Dept Comp Sci Tianjin 300072 Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

ISBN: (纸本)9781424423835

In order to eliminate oscillation arisen from AIMD window control strategy in TCP, an adaptive PI rate controller (PI-RCA) was proposed to smooth the traffic and to prevent network from congestion. Theoretical analysis and simulation evaluation showed that PI-RCA can make flow control system achieve stability robustness and adapt to sudden changes in network environment, thus providing the network with good transient behaviors. In this paper, we present an implemental evaluation of PI-RCA. We first implemented PI-RCA in the Linux kernel and solved various system issues. Second, we conducted some experiments to validate the previous simulation results. Compared with TCP, the experimental results show that the PI-RCA is much more easily to maximize link/per-flow utilization, to achieve fairness and nearly zero packet drops rate.

关键词： congestion control active queue management control algorithm proportional-integral control experiment

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Rendezvous Maneuvers of Multiple Spacecraft Using Differential Drag Under J₂ Perturbation

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JOURNAL OF GUIDANCE control AND DYNAMICS 2008年第6期31卷 1595-1607页

作者： Bevilacqua, R. Romano, M. USN Postgrad Sch Dept Mech & Astronaut Engn Monterey CA 93943 USA USN Postgrad Sch Space Syst Acad Grp Monterey CA 93943 USA

In this work, the residual atmospheric drag is exploited to perform rendezvous maneuvers among multiple spacecraft in low Earth orbits. These maneuvers are required, for instance, for autonomous on-orbit assembly. By varying the level of aerodynamic drag of each spacecraft, relative differential accelerations are generated among the spacecraft of the group and therefore their relative orbits are controlled. Each of the spacecraft is assumed to include a drag plate, which can be actively opened or closed, to vary the atmospheric drag. The recently developed Schweighart-Sedwick model is used to describe the relative dynamics of different spacecraft with respect to a circular orbit with the inclusion of J(2) effects. Furthermore, the natural relative dynamics of each chaser with respect to the target is decoupled into a secular motion and a periodic oscillation. In particular, the following two-phase control method is proposed. First, the secular motion of each chaser is controlled via differential drag in order for the spacecraft to sequentially move from an arbitrary initial condition to a closed stable relative orbit around the target spacecraft. After the relative orbit stabilization, a relative eccentricity control is applied to each spacecraft to zero-out the semi-axis of the relative orbit around the target and to achieve the rendezvous condition. The control algorithm considers mutual constraints among the values of differential drag that the different spacecraft can experience. Potential collisions are avoided by changing the maneuvering initial time. The main advantage of the proposed technique is that it enables a fleet of spacecraft to rendezvous without propellant expenditure. Furthermore, no numerical optimization is needed, because the control policy is based on closed-form analytical solutions. The proposed technique was validated via numerical simulations.

关键词： Spacecrafts Spacecraft Robotics Laboratory ISS Aerodynamic Drag Earth Orbital Period Monte Carlo Simulation control algorithm Propellant Target Spacecraft

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Coordinated standoff tracking of moving targets using Lyapunov guidance vector fields

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JOURNAL OF GUIDANCE control AND DYNAMICS 2008年第2期31卷 290-306页

作者： Frew, Eric W. Lawrence, Dale A. Morris, Steve Univ Colorado Boulder CO 80302 USA MLB Co Mountain View CA 94043 USA

This paper presents a control structure for cooperative stand-off line-of-sight tracking of a moving target by a team of unmanned aircraft based on a Lyapunov guidance vector field that produces stable convergence to a circling limit cycle behavior. A guidance vector field is designed for a stationary target and then modified with a correction term that accounts for a moving target and constant background wind. Cooperative tracking by multiple unmanned aircraft is achieved through additional phasing, also with a Lyapunov stability analysis. Convoy protection, in which the unmanned aircraft must scout an area ahead of the moving target, is performed by extending the cooperative stand-off line-of-sight limit cycle attractor along the direction of travel. Simulation results demonstrate the behavior of the algorithms as well as the improvement that results from cooperation. Finally, simulations of a larger cooperative search, acquisition, and tracking scenario are described that illustrate the use of the cooperative standoff line-of-sight and convoy protection controllers in a realistic application.

关键词： Lyapunov Stability Theory Standoff Tracking Flight control System Aircraft Speed Track algorithm Optimization algorithm Heading Angle Guidance Laws GPS control algorithm

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