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Feedforward Control of Deformable Membrane Mirrors for Adaptive Optics

IEEE TRANSACTIONS ON CONTROL systemS TECHNOLOGY 2013年第3期21卷 579-589页

作者： Ruppel, Thomas Dong, Shihao Rooms, Frederic Osten, Wolfgang Sawodny, Oliver Univ Stuttgart Inst Syst Dynam D-70569 Stuttgart Germany Univ Stuttgart Inst Tech Opt D-70569 Stuttgart Germany ALPAO F-38330 Biviers France

In this paper, performance enhancements for deformable membrane mirrors based on model-based feedforward control are presented. The investigated deformable mirror consists of a flexible membrane and voice coil actuators. Feedback control of the distributed actuators cannot be implemented in these mirrors due to a lack of high speed internal position measurements of the membrane's deformation. However, by using feedforward control, the dominant dynamics of the membrane can still be controlled allowing for faster settling times and reduced membrane vibrations. Experimental results are presented for an ALPAO deformable mirror with 88 distributed actuators on a circular membrane with a pupil of two centimeters in diameter.

关键词： Adaptive optics deformable membrane mirror distributed parameter system feedforward control

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Cantilevered plate Rayleigh-Ritz trial function selection for von Karman's plate equations

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JOURNAL OF AIRCRAFT 2007年第2期44卷 654-661页

作者： Attar, Peter J. USAF Computat Sci Branch Wright Patterson AFB OH 45433 USA

The accuracy and convergence characteristics of the classical Rayleigh-Ritz solution of the nonlinear von Kariman plate equations are studied with respect to the types of cantilever plate in-plane trial functions used in the solution. The static deflection of the cantilever plate is computed for an applied static gravity loading. Four different in-plane trial function types are studied. In each of these cases the same out-of-plane trial functions are used. It is found that in two of the four cases good convergence and accuracy are achieved when compared to the solution from a nonlinear finite element model. The degree of satisfaction of the problem natural boundary conditions is also examined, and it is shown that for the two cases that show inadequate convergence characteristics this satisfaction is poor. It is noted in particular that for these two cases at points on the problems' free boundaries, the in-plane trial functions satisfy, either exactly or approximately, the linear in-plane natural boundary conditions. At these points the addition of inplane degrees of freedom to the solution will not contribute to the satisfaction of the nonlinear natural boundary condition. Thus for these two cases the convergence is poor as more in-plane trial functions are added to the solution. The change in the statically loaded plate natural frequencies are also computed. Similar to the static deflection results, convergence to the nonlinear finite element solution Is slow when in-plane trial functions are used that approximately satisfy the linear in-plane boundary conditions.

关键词： Finite Element Modeling Cantilever Plate Theory Membrane Stress Rayleigh Ritz Method Angle of Attack Supersonic Flow Elastic Modulus distributed parameter system Structural Mechanics

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Boundary control of an Euler-Bernoulli beam with input and output restrictions

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NONLINEAR DYNAMICS 2018年第2期92卷 531-541页

作者： Liu, Zhijie Liu, Jinkun He, Wei Beihang Univ Sch Automat Sci & Elect Engn Beijing 100191 Peoples R China Univ Sci & Technol Beijing Sch Automat & Elect Engn Beijing 100083 Peoples R China

In this study, boundary control is considered for an Euler-Bernoulli beam subject to bounded input, bounded output, and external disturbances. Through utilizing the backstepping technology, a boundary control scheme is designed based on the original partial differential equations to regulate the vibration of the beam. An auxiliary system based on a smooth hyperbolic function is designed to handle the impact of the restricted input. And a barrier Lyapunov function is adopted to eliminate the impact of output restriction. It is proved that the input and output restrictions are circumvented simultaneously. Simulations are demonstrated for illustration.

关键词： Euler-Bernoulli beam Input and output restrictions distributed parameter system Boundary control

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Nonlinear H_∞ control for heat exchangers controlled by the manipulation of flow rate

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NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS 1997年第4期30卷 2237-2248页

作者： Kanoh, H Itoh, T Abe, N Meiji Univ Sch Sci & Technol Tokyo 101 Japan

No abstract available

关键词： nonlinear H infinity control bilinear process heat-exchanger distributed parameter system flow-rate control

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Integrated spatiotemporal modeling and mixed-integer approximate dynamic programming for ASP flooding

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JOURNAL OF PROCESS CONTROL 2021年 105卷 179-203页

作者： Liu, Zhe Li, Shurong Guo, Lanlei Ge, Yulei Beijing Univ Posts & Telecommun Sch Artificial Intelligence Beijing 100876 Peoples R China SINOPEC Shengli Oilfield Co Ltd Geol Sci Res Inst Dongying 257000 Peoples R China China Univ Petr East China Coll Control Sci & Engn Qingdao 266580 Peoples R China

Alkali-surfactant-polymer (ASP) flooding holds a critical position in oil development. This paper is concerned with the distributed parameter system (DPS) modeling and development scheme optimization of ASP flooding. Owing to the neglect of coupling among three-dimensional (3-D) spatial information, most of the existing data-driven modeling methods fail to provide a high-precision model for this type of strongly nonlinear and spatiotemporal coupling 3-D DPS. To overcome this shortcoming, an integrated spatiotemporal modeling method (ISM) is proposed, which reconstructs temporal-spatial relationship to avoid spatial mapping distortion based on canonical polyadic decomposition (CPD), and a spatiotemporal MSSO-LS-SVM algorithm is presented to compensate the nonlinear dynamics and decrease truncation error. Moreover, the synchronous optimization of ASP injection strategy and oil wells switching scheduling is an urgent industry requirement of intelligent oilfield decision system, which can be described a mixed-integer optimal control/dynamic programming problem. This paper first puts forward a mixed-integer approximate dynamic programming (MIADP) algorithm, dedicated for solving this class of optimal control problem with integer control subset requirements. In the MIADP, a parallel mixed-integer policy improvement framework is developed, where (i) the continuous control weight updates by the temporal difference (TD) error, (ii) the quantum evolution mechanism is designed to learn the integer control, and (iii) the two parts share information interactively and iterate to approach the optimal mixed-integer policy. At last, a case study on ASP flooding is taken, and the superior performance metrics illustrate the effectiveness of the proposed ISM method and MIADP algorithm. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： distributed parameter system Canonical polyadic decomposition Mixed-integer dynamic programming ASP flooding

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Infinite dimensional observer for a flexible robot arm with a tip load

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ASIAN JOURNAL OF CONTROL 2008年第4期10卷 456-461页

作者： Nguyen, To Duc Egeland, Olav Norwegian Univ Sci & Technol Fac Informat Technol Math & Elect Engn N-7491 Trondheim Norway

This note addresses observer design for a flexible robot arm with a tip load. The robot arm is modeled as an Euler-Bernoulli beam. The beam is clamped to a motor at one end and attached to a force actuator at the other. Based on boundary measurements, an exponentially stable observer is proposed. The existence, uniqueness, and stability of solutions of the observer are proven using semigroup theory. The results are illustrated by simulation.

关键词： distributed parameter system beam equation infinite dimensional observer semigroup

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Design of stabilizing control laws for mechanical systems based on Lyapunov's method

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1996年第1期19卷 172-180页

作者： Ohtsuka, T Fujii, HA TOKYO METROPOLITAN INST TECHNOL DEPT AEROSP ENGNTOKYO 191JAPAN

Design methods of stabilizing control laws are discussed for general mechanical systems. Hamiltonians of the mechanical systems are assumed not to depend on time explicitly, but the mechanical systems may embody elastic bodies and nonlinear motions. The methods are based on Lyapunov's second method for stability analysis, and the equations of motion of the controlled systems are not necessary for control design. A candidate for the Lyapunov function is the composition of the Hamiltonians of the subsystems in a given system. A sufficient condition of stabilizing control laws is derived and is extended so as to allow a class of frequency-dependent control laws with positive real filters, observers, or prefilters. The multiplier method (augmented Lagrangian method) is also introduced to attain desirable equilibrium in the closed-loop systems and results in integral control action. Slew maneuver of a flexible beam is employed as a design example to demonstrate the closed-loop characteristics of several control laws based on the present method.

关键词： distributed parameter system Control systems Augmented Lagrangian Method Bending Moment Vibration Suppression Rigid Manipulators Robots Numerical Simulation Nonlinear systems Feedback Law

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GENERAL ATTITUDE MANEUVERS OF SPACECRAFT WITH FLEXIBLE STRUCTURES

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1995年第2期18卷 264-271页

作者： LIN, YY LIN, GL National Cheng Kung University Tainan Taiwan Republic of China

An efficient composite control strategy is proposed in this paper permitting simultaneous multi-axis reorientation of a spacecraft with flexible structures. The proposed control, separating large and small motions of the dynamic system, includes three parts that can be independently designed and tuned. For each maneuver, an open-loop referencing attitude control trajectory is derived by considering the spacecraft as rigid and executed by part 1. Flexural deformations of the structures are stabilized by part 2. Part 3, encompassing part 1 and part 2 control results and external disturbances, is an optimal guidance that tracks part 1 reference trajectory and achieves the specified final attitude in finite time. Three simulation cases are included in which a flexible model spacecraft is used. Collocated actuators and sensors are placed on the hub and on the flexible structures of the spacecraft.

关键词： Flexible Structures Spacecrafts distributed parameter system Attitude Control Actuators Sensors Feedback Control Riccati Equations Reaction Wheels Ground Control Station

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Boundary Control of a Flexible Riser With the Application to Marine Installation

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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2013年第12期60卷 5802-5810页

作者： He, Wei Zhang, Shuang Ge, Shuzhi Sam Univ Elect Sci & Technol China Sch Automat Engn Chengdu 611731 Peoples R China Univ Elect Sci & Technol China Inst Robot Chengdu 611731 Peoples R China Natl Univ Singapore Dept Elect & Comp Engn Singapore 117576 Singapore Univ Elect Sci & Technol China Sch Comp Sci & Engn Inst Robot Chengdu 611813 Peoples R China

This paper investigates the control problem of a marine riser installation system. The riser installation system consisting of a vessel, a flexible riser, and a subsea payload is modeled as a distributed parameter system with one partial differential equation and four ordinary differential equations. Based on Lyapunov's direct method, adaptive boundary control is proposed at the top and bottom boundaries of the riser to position the subsea payload to the desired set point and suppress the riser's vibration. With the proposed control, uniform boundedness of the steady-state error between the boundary payload and the desired position is achieved by suitably choosing the design parameters. Numerical simulations are presented for demonstrating the effectiveness of the proposed control.

关键词： Adaptive control boundary control distributed parameter system flexible riser partial differential equation

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Boundary control of harmonic disturbances on flexible cantilever beams using piezoelectric patch actuators

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JOURNAL OF VIBRATION AND CONTROL 2016年第18期22卷 3916-3929页

作者： Karagiannis, Dimitrios A. Clayton, Garrett M. Nataraj, C. Villanova Univ Dept Mech Engn Ctr Nonlinear Dynam & Control CENDAC Villanova PA 19085 USA

This work addresses the control of vibrations in flexible structures caused by external harmonic disturbances using a boundary control method. The research is motivated by practical systems where beam-like structures require vibration suppression to prevent fatigue and system damage, or to increase efficiency. Importantly, this paper addresses a practical constraint of the actuation points being at the boundaries only. The method presented here is an open-loop control scheme which requires knowledge of the harmonic disturbance and a model of the flexible system. The controller uses the model, developed using the Rayleigh-Ritz method, to predict the reaction of the beam to the known input disturbance and compute an optimized control input which reduces the steady state vibration in the system. By properly choosing the cost function, the controller can be used to reduce the total vibration or to reduce the vibration in certain spatial locations. The method's vibration reduction capabilities are studied over a range of frequencies;data collected from experiments on a physical beam model is used to validate the predicted behavior of the system.

关键词： Boundary control vibration control beam vibration piezoelectric actuators experimental validation optimization distributed parameter system

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