Design and Research of Digital Decimation Filter Based on FPGA

2011 ◽  
Vol 105-107 ◽  
pp. 2086-2091
Author(s):  
Yao Li

This paper studies and analyses various digital filter and decimation structure. On this basis, by using QUARTUS development system design the decimation device modules, through the waveform simulation validated its correctness. Finally,a program is written into FPGA chip by the hardware platform. In the digital down conversion (DDC), CIC (cascade integral comb) filter plays an important role. It is mainly used for sampling rate, as well as low-pass filter effect. The main characteristics of CIC filter, using only adders, subtractor and register (no multiplier), so fewer resources occupied, implementation is simple and high speed. Based on the analysis of the principle of CIC filter,simulate and synthesize based on the theory of using VHDL language in FPGA. And successful application in the development of DDC chip. Keyword: CIC (cascade integral comb) filter,FPGA,VHDL

2013 ◽  
Vol 437 ◽  
pp. 840-844 ◽  
Author(s):  
Xiao Gang Liu ◽  
Bing Zhao

This paper use the passive vision system through high-speed camera collects molten pool images; and then according to the frequency domain characteristics of the weld pool image Butterworth low-pass filter; gradient method for image enhancement obtained after pretreatment. Research Roberts, Sobel, Prewitt, Log, Zerocross, and Canny 6 both traditional differential operator edge detection processing results. Through comparison and analysis of choosing threshold for [0.1, 0. Canny operator can get the ideal molten pool edge character, for subsequent welding molten pool defect recognition provides favorable conditions.


2011 ◽  
Vol 105-107 ◽  
pp. 1966-1969
Author(s):  
Tao Guo ◽  
Jie Zhu ◽  
Gui Tang ◽  
Yan Xu

It is a challenging problem to test the acceleration of the high-speed missiles and space shuttle under high temperature. This paper proposed a design of LC-resonant and high-temperature resistant acceleration sensors about the phenomenon. With the operational amplifier OP4177, it produces the input signal that contents with A/D (Analog to Digital) signal. An eight level low-pass filter MAX291 is used for testing after the signal is regulated. This design mainly uses AD7934 to complete the conversion from analog signals to digital signals. It also recognizes the resonant point of LC acceleration sensor by the DSP (Digital Signal Processing)recognizing program. The acceleration is computed finally by the DSP chip.


2014 ◽  
Vol 936 ◽  
pp. 2230-2234
Author(s):  
Ya Ping Yu ◽  
Hui Zhao ◽  
Yuan Liu ◽  
Ren Jie Yang ◽  
Gui Mei Dong ◽  
...  

This paper designed a range of 0.1 ~ 250 kHz sine wave sweeping constant current source, which sine wave generator based on FPGA chip and DDS technology, the desired sine wave frequency was obtained by controlling the frequency control words. Low-pass filter circuit was realized by using the LTC1560-1, conversion circuit from the voltage to the current was consisted of a Howland current pump. The constant current source shows a good spectral impedance purity and amplitude.


2020 ◽  
Author(s):  
Gizem Izgi ◽  
Stefanie Donner ◽  
Felix Bernauer ◽  
Daniel Vollmer ◽  
Klaus Stammler ◽  
...  

<p>Rotational motions play a key role in measuring seismic wavefield properties. To fully understand and describe the behavior of seismic waves, both translational and rotational components should be properly investigated. Portable blueSeis-3A (iXblue) sensors allow to measure 3 components of rotational motions with high sensitivity in a frequency range from 0.001 Hz to 50 Hz.</p><p align="justify">A huddle test was performed in Fürstenfeldbruck, Germany by the University of Potsdam in collaboration with the Ludwig-Maximilians University of Munich (LMU) and Federal Institute for Geosciences and Natural Resources (BGR) between 26 of August and 02 of September 2019, in order to further investigate the performance of multiple rotational instruments in combination with seismometers. Within the scope of this test, 5 rotational and 3 translational sensors were deployed on the basement of the observatory on decoupled plinth. Our preliminary results show good correlation between all components and rotational sensors. To investigate the coherent noise between sensors, we applied a 50 Hz low-pass filter and 100 Hz sampling rate. To better illustrate, probabilistic power spectral densities and spectrograms have been created. In general, we will discuss the reliability of the data recorded by rotational sensors for further investigations.</p><p> </p>


Author(s):  
Francesco Centurelli ◽  
Pietro Monsurro ◽  
Giuseppe Scotti ◽  
Pasquale Tommasino ◽  
Alessandro Trifiletti

2011 ◽  
Vol 382 ◽  
pp. 88-91
Author(s):  
Li Hong Zhang ◽  
Ying Bo Liang

By using non-negativity and support constraints recursive inverse filtering ,blind image restoration can be realized. But it’s difficult to resolve the proplem of sensitive to noise,so there has been no practical application. In this paper,according to the characteristic of NAS-RIF algorithm and the question of fuzzy by fabric defects images moving at a high-speed line, methods have been introduced, firstly, Adopt boundary keep smoothing filter as the de-noising pretreatment was carried out for image signal; Secondly, in each iteration of restoration,add the low-pass filter link。Thus,the problem of NAS-RIF algorithm is solved well.The simulation results show that this method has a satisfactory outcome both in visual impression and quantitative analysis.


2014 ◽  
Vol 1070-1072 ◽  
pp. 755-758
Author(s):  
Yun Feng Ma ◽  
Wei Zong

The high-speed railway is a typical ground systems, if subjected to a larger GIC, will lead to serious incidents. For the power supply and wiring pattern of high-speed railway is different from the public grid, then how to monitor the GIC impact on the high-speed rail electrical systems need to be studied. The paper study the process and pattem of GIC in high-speed rail track circuit, and propose a signal acquisition method of GIC in the track circuit. The sampled signal will be go through the low-pass filter designed by the window function to obtain the GIC.


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