Optimized calibration strategy for high order adaptive optics systems in closed-loop: the slope-oriented Hadamard actuation

Abstract A 1178 J near diffraction limited 527 nm laser is realized in a complete closed-loop adaptive optics (AO) controlled off-axis multi-pass amplification laser system. Generated from a fiber laser and amplified by the pre-amplifier and the main amplifier, a 1053 nm laser beam with the energy of 1900 J is obtained and converted into a 527 nm laser beam by a KDP crystal with 62% conversion efficiency, 1178 J and beam quality of 7.93 times the diffraction limit (DL). By using a complete closed-loop AO configuration, the static and dynamic wavefront distortions of the laser system are measured and compensated. After correction, the diameter of the circle enclosing 80% energy is improved remarkably from 7.93DL to 1.29DL. The focal spot is highly concentrated and the 1178 J, 527 nm near diffraction limited laser is achieved.

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The Adaptive Neural Control for a Class of High-Order Uncertain Stochastic Nonlinear Systems

Mathematical Problems in Engineering ◽

10.1155/2018/4620125 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10

Author(s):

Xiaoyan Qin

Keyword(s):

Nonlinear Systems ◽

Neural Control ◽

Closed Loop ◽

Control Method ◽

High Order ◽

Stochastic Nonlinear Systems ◽

Closed Loop System ◽

Adaptive Neural Control ◽

Control Scheme ◽

Approximation Capability

This paper studies the problem of the adaptive neural control for a class of high-order uncertain stochastic nonlinear systems. By using some techniques such as the backstepping recursive technique, Young’s inequality, and approximation capability, a novel adaptive neural control scheme is constructed. The proposed control method can guarantee that the signals of the closed-loop system are bounded in probability, and only one parameter needs to be updated online. One example is given to show the effectiveness of the proposed control method.

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An optimized calibration strategy for high order adaptive optics systems : the Slope-Oriented Hadamard Actuation

1st AO4ELT conference - Adaptive Optics for Extremely Large Telescopes ◽

10.1051/ao4elt/201007009 ◽

2010 ◽

Author(s):

S. Meimon ◽

T. Fusco ◽

C. Petit

Keyword(s):

Adaptive Optics ◽

High Order

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Optimization of adaptive optics correction during observations: algorithms and system parameters identification in closed-loop

10.1117/12.926574 ◽

2012 ◽

Cited By ~ 1

Author(s):

Clémentine Béchet ◽

Michel Tallon ◽

Éric Thiébaut

Keyword(s):

Adaptive Optics ◽

Closed Loop ◽

Parameters Identification ◽

System Parameters

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The PALM-3000 high-order adaptive optics system for Palomar Observatory

10.1117/12.789777 ◽

2008 ◽

Cited By ~ 11

Author(s):

Antonin H. Bouchez ◽

Richard G. Dekany ◽

John R. Angione ◽

Christoph Baranec ◽

Matthew C. Britton ◽

...

Keyword(s):

Adaptive Optics ◽

High Order ◽

Adaptive Optics System

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Global fixed-time stabilization for a class of uncertain high-order nonlinear systems with dead-zone input nonlinearity

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331218788614 ◽

2018 ◽

Vol 41 (7) ◽

pp. 1888-1895

Author(s):

Fangzheng Gao ◽

Yanling Shang ◽

Yuqiang Wu ◽

Yanhong Liu

Keyword(s):

Nonlinear Systems ◽

State Feedback ◽

Closed Loop ◽

Dead Zone ◽

Fixed Time ◽

High Order ◽

Closed Loop System ◽

Sign Function ◽

Input Nonlinearity ◽

Power Integrator

This paper considers the problem of global fixed-time stabilization for a class of uncertain high-order nonlinear systems. One distinct characteristic of this work is that the system under consideration possesses the dead-zone input nonlinearity. By delicately combining the sign function with a power integrator technique, a state feedback controller is designed such that the states of the resulting closed-loop system converge to the origin within a fixed time. A simulation example is provided to illustrate the effectiveness of the proposed approach.

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