H∞ Suboptimal controller design for adaptive optic systems

Erol, Bilal; Altıner, Berk; Adali, Erkan; Delibaşı, Akın

doi:10.1177/0142331218780217

Cited by 3 publications

(6 citation statements)

References 40 publications

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“…where (r,θ) is the polar coordinate in the circular domain; N is the number of Zernike terms; a i is the coefficient of the i-th Zernike polynomial. We refer to the mean square parameter associated with the wavefront coefficient as the distortion amplitude, and Z i is the i-th Zernike polynomial, which can be expressed as [30]:…”

Section: Phase Wavefront Distortionmentioning

confidence: 99%

Effect of Wavefront Distortion on the Performance of Coherent Detection Systems: Theoretical Analysis and Experimental Research

Yang

Xing

et al. 2023

Photonics

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Atmospheric turbulence causes signal beam wavefront distortion at the receiving end of a coherent detection system, which decreases the system mixing efficiency. Based on the coherent detection theory, this study establishes a mathematical model of wavefront distortion with mixing efficiency and mixing gain. It also analyzes the improvement limits of wavefront correction on mixing efficiency and mixing gain under different atmospheric turbulence intensities and experimentally measures them. Simulation results show that the mixing efficiency can be improved to 51%, 55%, and 60% after correcting for tilt, defocus, and astigmatism terms, respectively, when turbulence intensity D/r0 is 2. The mixing gain with homodyne detection is 3 dB higher than heterodyne detection. Meanwhile, the wavefront correction orders required for optimal mixing efficiency are higher than the heterodyne correction order. In the experiment, Haso4 NIR + DM 40 was used, and the turbulence intensity D/r0 was 2. After the closed-loop control algorithm corrects the tilt, defocus, and astigmatism terms, the indoor experimental results showed that the mixing efficiency is improved to 36%, 47%, and 62%, respectively. The outdoor experimental results showed that the mixing efficiency improved to 36%, 51%, and 68%, respectively.

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Section: Phase Wavefront Distortionmentioning

confidence: 99%

Effect of Wavefront Distortion on the Performance of Coherent Detection Systems: Theoretical Analysis and Experimental Research

Yang

Xing

et al. 2023

Photonics

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“…In the literature, the atmospheric turbulence which is one of the main sources of optical distortions is modeled as a low-pass filter structurewhere fci is the cut-off frequency values of the low-pass filter structures with respect to the Zernike polynomial index n i and it can be calculated by using a heuristic equationwhere scriptV is the atmospheric wind speed and L D is the input lens diameter (please see Baudouin et al (2008) and Erol et al (2019) for a more detailed discussion). In this paper, inspired from the above modeling which is widely used in the literature, the cut-off frequencies are assumed to be unknown frequencies of the wavefront trajectory and external disturbances.…”

Section: Mathematical Model Of the Deformable Mirrormentioning

confidence: 99%

“…where V is the atmospheric wind speed and L D is the input lens diameter (please see Baudouin et al (2008) and Erol et al (2019) for a more detailed discussion). In this paper, inspired from the above modeling which is widely used in the literature, the cut-off frequencies are assumed to be unknown frequencies of the wavefront trajectory and external disturbances.…”

Section: 1zernike Polynomialsmentioning

confidence: 99%

“…This problem is addressed in Kim et al (2011) with normalℋ∞ control and recently in Guo et al (2021) with LQG control for the Chinese Large Solar Telescope. The reduced-order normalℋ∞ controller design for the practical reasons is concerned in Erol et al (2019). The main drawback of normalℋ∞ control design is that the frequency range of disturbance is assumed to be known.…”

Section: Introductionmentioning

confidence: 99%

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Adaptive output regulation of the adaptive optics system

Altıner

Doğan

Daşdemir

2022

Journal of Vibration and Control

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Deformable mirrors are very efficient optical devices that are used in correcting wavefront aberrations and are core elements of adaptive optics systems. Its promising success allows it to operate in a large field of applications. Hence, one of the most important problems in the control of adaptive optics systems is to design a controller that can achieve perfect wavefront correction in completely unknown environmental conditions. To achieve this goal, this study proposes an adaptive internal model control design for deformable mirrors. Considering deformable mirrors as a flexible plate equation, an adaptive internal model-based controller is designed and the effectiveness of the proposed method despite abrupt changes in disturbance is proven by simulation results.

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“…In Böhm and Sawodny (2016), nonlinear behaviour of air gap between actuators and membrane deformable mirror is taken into account in control of linear distributed parameters model of a deformable mirror. Reduced order H ∞ controller design for deformable mirrors augmented with atmospheric turbulence dynamics is presented in Erol et al (2019).…”

Section: Introductionmentioning

confidence: 99%

H∞ controller design for the mitigation of atmospheric effects on the laser beam pointing

Subaşı

Erol

Altıner

et al. 2021

Transactions of the Institute of Measurement and Control

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In this paper, the control of a fast steering mirror, which is the core element of an adaptive optics system, is investigated to suppress the beam jitter. The main source of the jitter is taken as the atmospheric turbulence. The effect of the atmospheric turbulence on the beam jitter is experimentally determined with respect to the two different refractive index structure parameters. The mathematical model of the fast steering mirror based on the atmoshperic turbulence data is obtained using the system identification. In order to overcome implementation problems, the low order proportional-integral-derivative (PID) type controllers, which minimize the [Formula: see text] norm of the closed loop system, are designed in the centralized and the decentralized settings. In addition to this, the fixed order weighted [Formula: see text] controller is based on the frequency characteristics of the atmospheric turbulence that is determined experimentally. Then, in order to show the effectiveness of the proposed low order PID type controller, the designed controllers are compared on the experimental setup. Finally, the simulation and the experimental results are presented. Comparison of advantageous and disadvantageous of centralized and decentralized controller architectures are discussed.

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H∞ Suboptimal controller design for adaptive optic systems

Cited by 3 publications

References 40 publications

Effect of Wavefront Distortion on the Performance of Coherent Detection Systems: Theoretical Analysis and Experimental Research

Effect of Wavefront Distortion on the Performance of Coherent Detection Systems: Theoretical Analysis and Experimental Research

Adaptive output regulation of the adaptive optics system

H∞ controller design for the mitigation of atmospheric effects on the laser beam pointing

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