A least-square design approach for 2D FIR filters with arbitrary frequency response

1999 ◽  
Vol 46 (8) ◽  
pp. 1027-1034 ◽  
Author(s):  
Wei-Ping Zhu ◽  
M. Omair Ahmad ◽  
M.N.S. Swamy
Keyword(s):  
Frequency Response ◽  
Least Square ◽  
Design Approach ◽  
Fir Filters ◽  
Arbitrary Frequency ◽  
2D Fir Filters

scholarly journals Gaussian Circular 2D FIR Filters Designed Using Analytical Approach

2020 ◽  
Vol 16 ◽  
Keyword(s):  
Analytical Approach ◽  
Design Procedure ◽  
Peak Frequency ◽  
Fir Filters ◽  
Chebyshev Series ◽  
Analytical Design ◽  
Frequency Transformation ◽  
Low Pass ◽  
Band Pass ◽  
2D Fir Filters

This paper proposes an analytical design procedure for a particular class of 2D filters, namelyGaussian-shaped, circularly-symmetric FIR filters. We approach both low-pass and band-pass circular filters,which are adjustable in selectivity and peak frequency. The design starts from a given 1D Gaussian prototypefilter, approximated using the Chebyshev series. A frequency transformation is applied to derive the circularfilter. Several design examples are provided for both types of filters. The filters designed through this methodare efficient, their frequency response results in a factored or nested form, convenient for implementation.

scholarly journals Vibration Parameters Estimation by Blade Tip-Timing in Mistuned Bladed Disks in Presence of Close Resonances

2020 ◽  
Vol 10 (17) ◽  
pp. 5930
Author(s):  
Saeed Bornassi ◽  
Christian Maria Firrone ◽  
Teresa Maria Berruti
Keyword(s):  
Frequency Response ◽  
Optimization Technique ◽  
Numerical Test ◽  
Parameters Estimation ◽  
Least Square ◽  
Response Curves ◽  
Bladed Disks ◽  
Bladed Disk ◽  
Resonance Frequencies ◽  
Blade Tip

The present paper is focused on the post processing of the data coming from the Blade Tip-Timing (BTT) sensors in the case where two very close peaks are present in the frequency response of the vibrating system. This type of dynamic response with two very close peaks can occur quite often in bladed disks. It is related to the fact that the bladed disk is not perfectly cyclic symmetric and the so called “mistuning” is present. A method based on the fitting of the BTT sensors data by means of a 2 degrees of freedom (2DOF) dynamic model is proposed. Nonlinear least square optimization technique is employed for identification of the vibration characteristics. A numerical test case based on a lump parameter model of a bladed disk assembly is used to simulate different response curves and the corresponding sensors signals. The Frequency Response Function (FRF) constructed at the resonance region is compared with the traditional Sine fitting results, the resonance frequencies and damping values estimated by the fitting procedure are also reported. Accurate predictions are achieved and the results demonstrate the considerable capacity of the 2DOF method to be used as a standalone or as a complement to the standard Sine fitting method.

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