scholarly journals Navigation Algorithm Applied to the Bit of Underwater Horizontal Directional Drilling in a Vibration Environment

2019 ◽  
Vol 36 (2) ◽  
pp. 249-256
Author(s):  
Ke Yang
Keyword(s):  
Angular Velocity ◽  
Spectral Characteristics ◽  
Sensor Data ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Navigation Algorithm ◽  
Low Pass ◽  
Kalman Filter Algorithm

Abstract In its working state, the bit used in underwater horizontal directional drilling (UHDD) produces a high-frequency vibration that can affect accuracy of navigation. We designed a low-pass filter with linear phase on the basis of spectral characteristics of sensor data. To improve further the accuracy of navigation, we deduce the state error model on the basis of the random walk model of acceleration and angular velocity. We use an indirect Kalman filter algorithm to correct the attitude and position of the bit used with UHDD on the basis of observations coming from our working state analysis. Last, we derive a complete navigation algorithm function, including the acquisition method of steady-state component of acceleration and angular velocity. Experimental results show that the navigation algorithm proposed in this paper can obtain accurate attitude and location information of the bit in a vibration environment.

Analysis on Adjusting Effect and Spectral Characteristics of Digital Image Sampling

2014 ◽  
Vol 539 ◽  
pp. 471-474
Author(s):  
Hai Ying Liu
Keyword(s):  
Digital Image ◽  
Hot Spot ◽  
Modern Art ◽  
Spectral Characteristics ◽  
Image Process ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Image Sampling ◽  
Low Pass ◽  
Continuous Tone

When it comes to the digitized image, it is a process of converting analog image of continuous tone which has been sampled and quantized into digital image. The application of digital technology in modern art has become one of the hot spot in this field. First of all, this paper undertakes the digital image process of image. According to the filtering properties of the Dirac function, this paper analyzes the two-dimensional sampling principle of digital image. Based on this, the relationship between image spectrum before sampling and after sampling is compared and analyzed according to the related properties of Fourier transform. And then it is obtained that it is concluded that the ideal low-pass filter can make the sample undistorted. By further analyzing the error of the sampling value quantification processing, the rebuilt best quantitative values of image can be obtained. Thats to say, the reconstruction of digital image is the inverse process of image sampling. To a certain extent, it provides scientific theoretical basis for the integration of digital image in modern art design.

Design of Programmable Wideband Low Pass Filter with Continuous-Time/Discrete-Time Hybrid Architecture

2017 ◽  
Vol E100.C (10) ◽  
pp. 858-865 ◽  
Author(s):  
Yohei MORISHITA ◽  
Koichi MIZUNO ◽  
Junji SATO ◽  
Koji TAKINAMI ◽  
Kazuaki TAKAHASHI
Keyword(s):  
Discrete Time ◽  
Continuous Time ◽  
Hybrid Architecture ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

ANALYSIS AND IMPROVEMENT TECHNIQUES FOR THE TRANSFER FUNCTION OF A PLANAR LOW - PASS FILTER

2016 ◽  
Vol 15 (12) ◽  
pp. 2579-2586
Author(s):  
Adina Racasan ◽  
Calin Munteanu ◽  
Vasile Topa ◽  
Claudia Pacurar ◽  
Claudia Hebedean
Keyword(s):  
Transfer Function ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

scholarly journals Simulating Elliptic Low-pass Filter based on MOCCCII

2020 ◽  
Vol 965 ◽  
pp. 012037
Author(s):  
Nanan Chomnak ◽  
Siradanai Srisamranrungrueang ◽  
Natapong Wongprommoon
Keyword(s):  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

scholarly journals Noise-Reducing Fabric Electrode for ECG Measurement

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4305
Author(s):  
Takamasa Terada ◽  
Masahiro Toyoura ◽  
Takahide Sato ◽  
Xiaoyang Mao
Keyword(s):  
Special Structure ◽  
Electrode Impedance ◽  
Electrode Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Chip Type ◽  
Low Pass ◽  
Filter Fabric

In this work, we propose a fabric electrode with a special structure that can play the role of a noise reduction filter. Fabric electrodes made of the conductive fabric have been used for long-term ECG measurements because of their flexibility and non-invasiveness; however, due to the large impedance between the skin and the fabric electrodes, noise is easily introduced into the ECG signal. In contrast to conventional work, in which chip-type passive elements are glued to the electrode to reduce noise, the proposed electrode can obtain a noise-reduced ECG by changing the structure of fabric. Specifically, the proposed electrode was folded multiple times to form a capacitor with a capacitance of about 3 nF. It is combined with the skin-electrode impedance to form a low-pass filter. In the experiment, we made a prototype of the electrodes and measured ECG at rest and during EMG-induced exercise. As a result, the SNR values at rest and during exercise were improved about 12.02 and 10.29 , respectively, compared with the fabric electrode without special structure. In conclusion, we have shown that changing the fabric electrode structure effectively removes noise in ECG measurement.

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