Frequency response function measurement and parametric SISO system modelling of a gyro-stabilized infrared electro optic gimbal system

In this research study, a single axis (inner azimuth gimbal) of a four-axis gyro-stabilized electro optic gimbal system is modelled through experimental investigation in the frequency domain, and the results of this investigation are presented. The dynamic behaviour of the mechanical system is obtained from input and output signals, strictly speaking, nonparametric measurements. Detecting and measuring the nonlinear distortions allows a better understanding and gives an intuitive insight into the error sources on frequency response function measurements. In this study, a nonparametric frequency response function and its uncertainty (noise) are measured; nonlinear distortions are quantified on a real-time system. The dynamic system is modelled by its parametric transfer function with various different estimation techniques and their efficiencies, convergence properties, and bias errors are compared and discussed. It turns out that, the nonparametric noise model allows the estimator to weight the cost function and reach statistically better results. As an original contribution, a common problem encountered with gimbals having small rotational movement capacity (in this case study, +/- 5 degrees for the inner gimbals) is formulated as an optimization problem. An optimization procedure is studied to achieve a better signal-to-noise ratio in the frequency band of interest, while satisfying device-specific constraints.


Nonlinear system identification and nonlinear experimental modal analysis by using response controlled stepped sine testing
Karaağaçlı, Taylan; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2020-12-24)
In this work, two novel nonlinear system identification methods are proposed in both the modal and spatial domains, respectively, based on response-controlled stepped-sine testing (RCT) where the displacement amplitude of the excitation point is kept constant throughout the frequency sweep. The proposed nonlinear modal identification method, which is also a nonlinear experimental modal analysis technique, applies to systems with several nonlinearities at different (and even unknown) locations (e.g. joint no...
Pulse phase resolved x-ray spectroscopy of four accretion powered millisecond pulsars
Çolak, Sıdıka Merve; Baykal, Altan; Department of Physics (2014)
In this thesis, pulse phase resolved X-ray spectroscopy of four accretion powered millisecond pulsars which are IGR J00291+5934 , IGR J17498-2921 , XTE J0929-314 and XTE J1807-294 will be presented. Phase dependent changes during their outbursts will be checked for possible correlations of spectral parameters such as photon index and blackbody temperature with rotation phase using archive of Rossi X-ray Timing Explorer (RXTE) observations. In the analysis of IGR J17498-2921 in 2011 outburst , positive corre...
Frequency-resolved spectroscopy of XB1323-619 using XMM-Newton data: detection of a reflection region in the disc
Balman, Şölen (Oxford University Press (OUP), 2010-09-21)
We present the frequency-resolved energy spectra (FRS) of the low-mass X-ray binary dipper XB1323-619 during persistent emission in four different frequency bands using an archival XMM-Newton observation. FRS method helps to probe the inner zones of an accretion disc. XB1323-619 is an Atoll source and a type-I burster. We find that the FRS is well described by a single blackbody component with kT in a range 1.0-1.4 keV responsible for the source variability in the frequency ranges of 0.002-0.04 and 0.07-0.3...
Wavelength dependence of the nonlinear absorption performance and optical limiting in Bi12TiO20 single crystal
PEPE, YASEMİN; Isik, Mehmet; KARATAY, AHMET; Hasanlı, Nızamı; ELMALI, AYHAN (2023-01-01)
In this study, the influence of excitation wavelength and input intensity on the nonlinear absorption (NA) mechanism and optical limiting behavior of the Bi12TiO20 (BTO) single crystal were reported. The energy band gap of the BTO single crystal was obtained to be 2.38 eV. Urbach energy revealed that the single crystal has a highly defective structure. Open aperture (OA) Z-scan experiments were conducted at 532 and 1064 nm excitation wavelengths at various input intensities. Obtained experimental data were ...
Time-resolved measurements of the B-2 Sigma state of SrF by laser spectroscopy
Berg, LE; Ekvall, K; Hansson, T; Iwamae, A; Zengin, V; Husain, D; Royen, P (1996-01-12)
We report a time-resolved investigation of the low-lying state, B-2 Sigma, of gaseous SrF using laser spectroscopy with the following derived zero-pressure lifetime tau(B (2) Sigma(v' = 0)) = 25.4 +/- 0.8 ns. Such measurements constitute an important contribution to our overall understanding of excited alkaline earth halides. They are also applied to the interpretation of molecular dynamic investigations of halogen atomic abstraction reactions by excited atoms, in the present case, Sr[5s5p(P-3(J))], with mo...
Citation Formats
G. Ozdogan and M. K. Leblebicioğlu, “Frequency response function measurement and parametric SISO system modelling of a gyro-stabilized infrared electro optic gimbal system,” TRANSACTIONS OF THE INSTITUTE OF MEASUREMENT AND CONTROL, pp. 512–528, 2016, Accessed: 00, 2020. [Online]. Available: