Improved Signal Processing Algorithm Research Articles

An improved signal processing algorithm for VSF extraction

Contactless detection of human beings via extracting vital sign features (VSF) is a perfect technology by employing an ultra-wideband radar. Only using Fourier transform, it is a challenging task to extract VSF in a complex environment, which can cause a lower signal to noise ratio (SNR) and significant errors due to the harmonics. This paper proposes an improved signal processing algorithm for VSF extraction via analyzing the skewness and standard deviation of the collected impulses. The discrete windowed Fourier transform technique is used to estimate the time of arrival of the pulses. The frequency of human breathing movements is obtained using an accumulation scheme in frequency domain, which can better cancel out the harmonics. The capabilities of removing clutters and improving SNR are validated compared with several well-known methods experimentally.

Investigation of a DC OCT signal processing method based on an improved Kalman algorithm

In this paper, we propose an improved Kalman filtering algorithm, to solve problems associated with processing of direct current (DC) signals in optical current transformers (OCTs). The algorithm was realized as follows. Based on the characteristics of the OCT, mixed noise was included with the parameters and state information of the measurement model, to ensure that it could be processed. State predictions and update equations for the improved Kalman algorithm were obtained, according to the minimum mean squared error criterion, using the established model. Finally, real-time noise estimation and correction was achieved by designing a recursive noise filter. Results from simulations and experiments demonstrate that the improved signal processing algorithm is effective in filtering mixed noise from DC signals measured by an OCT. Furthermore, the proposed algorithm is able to achieve real-time noise correction during the filtering process.

RESEARCH OF CHARACTERISTICS OF SOLID IMPURITIES AND LIQUID SENSOR-ALARMS DURING OPERATION OF WELLS WITH DIFFERENT CONSTRUCTIONS OF PRODUCTION HORIZON TAPPING

The use of sensor-alarms (SA) of Sigma-Optic JSC integrated into the remote control system of the Cenomanian boreholes of the Kharvutinskaya area Yamburgskoye oil and gas condensate field is carried out to control the content of solid impurities and liquid in the gas flow at five levels in the DSP-EAC-2 modification and seven levels in the modification of DSP-EAC-2. The article presents the results of research on characteris- tics and a comparative analysis of indications of regular and upgraded SA in the frame of complex gas dynamic studies. Analysis of field data for the period of standard sensors operation has shown the need for separate signals extraction for the content of the phase components of mechanical impurities: sand and hydrate structures. When studying the SA character- istics in laboratory conditions, different forms of pulses-responses of the action of elastoplastic impacts of hydrate particles and elastic impacts of sand particles were experimentally established. The main differences between the modifications of DSP-EAC-2 are as follows: an improved signal processing algorithm, a variable power supply scheme and an extended range of levels of excess phase components in the formation mixture. A controlled range of SA operation is established for the content of the dropping liquid in the gas flow from 6 to 100 liters per hour (0.144- 2.4 m³ per day). Synchronous registration and satisfactory comparative readings of SA are shown in conditions of constant fluid flow from the bottom of the well.

Improved Signal Processing Algorithm Based on Wavelet Transform

Wavelet analysis is a rapidly developing emerging discipline, at present; it has been widely used in practice. Study wavelet’s new theory, new method and new application have important theoretical significance and practical value. Based on the problem of poor performance of using traditional wavelet transformation algorithm in signal denoising, this paper puts forward a improved scheme based on tradeoff between soft and hard threshold, the scheme is established on the basis of traditional soft threshold, hard threshold, and the obtained estimated wavelet coefficients value of this scheme are between soft threshold and hard threshold methods, so call it the tradeoff between soft and hard threshold method. Implementation steps of the improved scheme based on soft and hard threshold tradeoff are, firstly establishing wavelet coefficient estimator of soft and hard threshold tradeoff method, and adding factor in threshold estimator, so as to adjust the size of the estimated wavelet coefficients. Simulation experiments show that the proposed soft, hard threshold tradeoff based signal threshold improved deniosing method shows a strong effect of the practical signal denoising, the obtained reconstructed signal SNR has been tremendously improved than the traditional denoising method.

3-Dimension Imaging System of Burden Surface with 6-radars Array in a Blast Furnace

Harsh environment in Blast Furnace (BF) poses a big challenge for metallurgical industrial radar measurement of burden surface for ore and coke. The improved signal processing algorithm enhances the real-time performance. Antenna is specially designed for continuous stable signal acquirement, high temperature resistance and anti-dust ability. The experiment results illustrate that the single radar meets the accuracy requirement of solid bulk material. A new BF Burden Surface Measuring System is developed for real-time BF 3-D imaging. Distributed 6-radars array mounted on the top of 2500 m 3 BF. A virtual 3-D imaging is achieved with a reconstruction algorithm of 6-radars array according to the actual shape of BF. 3-D imaging system with 6-radars array provides an improved technique for intelligent control of burden distribution during BF iron making process.

Improved max-min scanning method for phase determination

We present an improved signal processing algorithm for the max-min scanning method for phase determination in speckle and other interferometric techniques. After recording the intensity changes at one point on the image for a range of arbitrary phase shifts, curve fitting is employed to obtain the intensity waveform corresponding to this position. The phase value is derived from this curve, and the sign of the computed phase angle is determined using the derivative of the fitting curve. The phase map is obtained by performing the same procedure throughout the entire image. This improved algorithm requires neither sorting the recorded image signals nor additional sign images. Experimental examples are provided.