Location of Wire Faults Using Chaotic Signal Generated by an Improved Colpitts Oscillator

2014 ◽  
Vol 24 (04) ◽  
pp. 1450053 ◽  
Author(s):  
Hang Xu ◽  
Bingjie Wang ◽  
Jingxia Li ◽  
Anbang Wang ◽  
Yuncai Wang
Keyword(s):  
Reference Signal ◽  
Chaotic Signal ◽  
Digital Signals ◽  
Probe Signal ◽  
Excellent Correlation ◽  
Colpitts Oscillator ◽  
Numerical Studies ◽  
Maximum Range ◽  
Short Circuits ◽  
Correlation Properties

We propose a method to locate wire faults using a chaotic signal generated by an improved Colpitts oscillator. The chaotic signal is divided into two parts: one serves as a reference signal, and the other serves as a probe signal which is sent down to the wire. The fault is detected by correlating the reference signal with the probe signal back-reflected from the fault. Experimental and numerical studies show that the chaotic signal generated by the improved Colpitts oscillator has a broad spectrum and excellent correlation properties. Using this chaotic signal, we experimentally prove our method can be used to locate open circuits, short circuits, impedance discontinuities and other different damage cases on wires, and also demonstrate its ability for testing live wires through the numerical simulation. The results show that a spatial resolution of 0.2 m and a maximum range of about 930 m can be achieved. Furthermore, the interference margin is about 167 dB for the digital signals such as Mil-Std 1553 data on wire.

Microwave-Photonic Sensor for Remote Water-Level Monitoring Based on Chaotic Laser

2014 ◽  
Vol 24 (03) ◽  
pp. 1450032 ◽  
Author(s):  
Yongning Ji ◽  
Mingjiang Zhang ◽  
Yuncai Wang ◽  
Peng Wang ◽  
Anbang Wang ◽  
...  
Keyword(s):  
Water Level ◽  
Reference Signal ◽  
Central Office ◽  
Single Mode ◽  
Chaotic Signal ◽  
Photonic Sensor ◽  
Microwave Photonic ◽  
Chaotic Laser ◽  
Level Monitoring ◽  
Water Level Monitoring

A microwave-photonic sensor for remote water-level monitoring based on chaotic laser is proposed and demonstrated. The probe chaotic signal with bandwidth of 18 GHz is generated in the central office and then transmitted at the remote antenna unit after a 24 km single-mode fiber transmission. And the monitoring data from the remote antenna unit is sent back to the central office over fiber. The water-level measuring is accomplished by cross-correlation between reference signal and probe signal at the central office. So the remote water-level monitoring system with a high spatial resolution of 2 cm is achieved and the height of water surface can be displayed in real time.

scholarly journals Sistema de control de temperatura on-off implementado en el proceso de termoformado para elaboración de bloque a partir de envases multicapas

2019 ◽  
pp. 17-21
Author(s):  
Jaime Rosales-Davalos ◽  
Ma. de los Ángeles Enriquez-Perez ◽  
Roberto López-Ramírez ◽  
Jorge Edmundo Mastache-Mastache
Keyword(s):  
Control System ◽  
Reference Signal ◽  
Control Process ◽  
Temperature Control System ◽  
Digital Signals ◽  
Analog Signals ◽  
Component Processes ◽  
Wall Construction ◽  
Thermoforming Process ◽  
And Control

In this work, a temperature control system (SCT) was designed and implemented in the thermoforming process for the manufacture of blocks for wall construction (BCM). The control process in the SCT consists in establishing the reference temperature for the thermoforming and send it to the Mega 2560 microcontroller. This component processes the input signal, obtaining six digital signals that control the surface temperature of each of the external faces of the BCM mold that has a rectangular prism geometry. These signals are sent to the electrical isolation stage where the actuators enable six electrical resistances (200 Watts to 120 Volts). The feedback of the temperature in the control system was made through type-k thermocouples, whose analog signals are compared with the reference signal to regulate the temperature. This project contributes to establish and control the temperature of the resistances, implemented for the thermoforming process, for the elaboration of blocks using multilayer containers.

scholarly journals Anti-interference pulsed laser ranging system

2020 ◽  
pp. 8-14
Author(s):  
A. V. Sadchenko ◽  
O. A. Kushnirenko ◽  
E. K. Koshelev
Keyword(s):  
Measurement Accuracy ◽  
Pulsed Laser ◽  
Cost Effective ◽  
Laser Rangefinder ◽  
Probe Signal ◽  
Coding Sequence ◽  
Probing Signal ◽  
Real Value ◽  
Range Interval ◽  
Correlation Properties

Pulsed laser rangefinders prove to be cost-effective and practical devices when used at distances of several tens of kilometers due to their compactness, portability and energy efficiency. However, the measurement accuracy is significantly reduced by the presence of pulsed interference affecting the input of the optical receiver both during the sensing period and when the reflected signal is being received. Using the algorithms with the accumulation and subsequent processing of the results of several successive measurements reduces the speed of decision-making and does not guarantee the convergence of the results to the real value of the distance. The paper proposes a structural diagram of a laser rangefinder with the ability to detect pulsed interference in the range interval and correct errors that occur in the structure of the signal reflected from the target. The basis of the rangefinder circuit is a logical consistent filter, the structure of which contains multipliers (multiplication operations). The following requirements were formulated for the structure of the probe signal: — the first element should always be set to +1 to synchronize the receiver decider; — the weight of the coding sequence is equal to half its length; — the length of the coding sequence is even. Based on the requirements for coding sequences, the optimal structures of binary probing signals of length 8 were found, providing the best corrective ability. Comparison of the correlation properties of the found sequences and the sequences that are constructed using the Walsh functions showed the advantage of the optimal sequences by the criterion of the minimum level of the ACF side lobes. The simulation of the rangefinder under pulsed noise conditions has shown that the logical filter is advisable to use for those cases when the duration of the obstacle does not exceed 1/3 of the duration of the probing signal.

Experimental Investigation of a Direct Chaotic Signal Radar with Colpitts Oscillator

2010 ◽  
Vol 24 (8-9) ◽  
pp. 1229-1239 ◽  
Author(s):  
T. Jiang ◽  
J. Long ◽  
Z. Wang ◽  
S. Qiao ◽  
W. Cui ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Chaotic Signal ◽  
Colpitts Oscillator

scholarly journals Method of frequency-phase detection used in ADC based on PLL circuit

2019 ◽  
pp. 26-30
Author(s):  
R. V. Magerramov
Keyword(s):  
Reference Signal ◽  
Phase Detector ◽  
Phase Detection ◽  
Digital Signals ◽  
Electronic Products ◽  
Analog To Digital ◽  
Pulse Converter ◽  
Multiple Frequencies ◽  
Analog Voltage ◽  
Frequency Phase

The phase‑locked loop (PLL) is an integral part of many electronic products in modern electronics and radio engineering, which is used to form and process analog and digital signals. One of the non‑standard applications of the PLL circuit is to implement an analog voltage‑to‑pulse converter. This application of the PLL circuit allows you to create an analog‑to‑digital converter (ADC) with high resolution, and the implementation features of the PLL circuit can provide a number of advantages, such as high noise immunity, compensation for the errors of passive elements, operation in a wide temperature range, etc. The accuracy of the conversion in such a device depends on both the separately designed blocks of the PLL circuit and the parameters of the system as a whole. The paper discusses the implementation of a digital frequency‑phase detector (FFD) operating in the range from 0 to 2p. The basis of his work is the method of frequency‑phase detection, which reduces the time of transients in the PLL circuit, and also eliminates the detection of coherent and multiple frequencies of the reference signal.

Chaos-Based Through-Wall Life-Detection Radar

2019 ◽  
Vol 29 (07) ◽  
pp. 1930020 ◽  
Author(s):  
Hang Xu ◽  
Liqiang Li ◽  
Ying Li ◽  
Jianguo Zhang ◽  
Hong Han ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Modulation Frequency ◽  
Correlation Method ◽  
Chaotic Signal ◽  
Detection Algorithm ◽  
Respiratory Frequency ◽  
Thick Wall ◽  
Probe Signal ◽  
Range Resolution ◽  
Life Detection

We propose a chaos-based through-wall life-detection radar utilizing a wideband Boolean-chaos signal as the radar probe signal. The range between the radar and the human target can be obtained by correlating the chaotic signal reflected from the human target with its delayed duplicate. Actually, this range is modulated periodically by human chest wall displacements along the time axis of recording signal and the modulation frequency is equal to the respiratory frequency. Therefore, we design a life-detection algorithm based on correlation method to extract the human’s respiratory frequency and range information from echo signals. Experimental results demonstrate that our radar can simultaneously detect the respiratory frequency and range of the human target behind a 20-cm-thick wall within the range of at least 5[Formula: see text]m. The dynamic range and range resolution can reach 35[Formula: see text]dB and 15[Formula: see text]cm, respectively. Furthermore, the excellent anti-interference performance of the proposed radar has also been demonstrated, which makes it especially suitable for search and rescue missions in complex electromagnetic environments.

Remote Imaging Radar with Ultra-Wideband Chaotic Signals Over Fiber Links

2015 ◽  
Vol 25 (11) ◽  
pp. 1530029 ◽  
Author(s):  
Hang Xu ◽  
Bingjie Wang ◽  
Hong Han ◽  
Li Liu ◽  
Jingxia Li ◽  
...  
Keyword(s):  
Chaotic Signal ◽  
Base Station ◽  
Ultra Wideband ◽  
Probe Signal ◽  
Range Resolution ◽  
Remote Imaging ◽  
Chaotic Signals ◽  
Fiber Link ◽  
Fiber Links ◽  
Central Station

We experimentally demonstrate radar remote imaging using a radio technique based on ultra-wideband chaotic signals over fiber links. The radar system includes three parts, i.e. a central station, some optical fiber links and a base station. At the central station, an ultra-wideband chaotic signal is generated from an improved Colpitts oscillator and then is up-converted as a probe signal. The probe signal is then converted to be in optical domain by the external modulation technique on laser diode for transmitting over a fiber link to a remote base station. At the base station, the probe signal is converted to be in electrical domain and then launched by a microwave antenna. After being received by another antenna, the echo signal from a target is converted to be in optical domain and then transmitted over a fiber link back to the central station. By optical-to-electrical conversion and down conversion, the echo chaotic signal is recovered. Utilizing the correlation method and back projection algorithm, an image of the target in the two-dimensional space can be realized at the central station. Our experiments successfully performed remote imaging for both planar and spherical reflectors with a distance over 10 km. The down-range resolution of 6-cm and 8-cm cross-range resolution were obtained, respectively. We will show that the power spectrum of the probe signal is adjustable in the spectral mask according to the Federal Communications Commission standards, therefore can avoid interference to the existing narrowband radio signals.

scholarly journals Locating Underground Pipe Using Wideband Chaotic Ground Penetrating Radar

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2913 ◽  
Author(s):  
Jingxia Li ◽  
Tian Guo ◽  
Henry Leung ◽  
Hang Xu ◽  
Li Liu ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Chaotic Signal ◽  
Projection Algorithm ◽  
Back Projection ◽  
Probe Signal ◽  
Echo Signal ◽  
Buried Pipes ◽  
Range Resolution ◽  
Detectable Range ◽  
Ground Penetrating

An experimental wideband chaotic ground penetrating radar is proposed to locate underground pipes. A chaotic signal with a bandwidth of 1.56 GHz is utilized as the probe signal. The localization of the pipes is achieved by correlating the chaotic echo signal with its delayed duplicate and back-projection algorithm. Experimental results demonstrate that plastic pipe, metallic pipe, and multiple pipes can be located with a range resolution of 10 cm. Limited by the height of the sand, the detectable range is estimated to be 0.7 m for both the plastic pipes and the metallic pipes when the transmitting power is −12 dBm. The proposed system has the potential to detect buried pipes, and it is suitable for geological and civil engineering applications.

scholarly journals A High-Resolution Leaky Coaxial Cable Sensor Using a Wideband Chaotic Signal

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4154
Author(s):  
Hang Xu ◽  
Jun Qiao ◽  
Jianguo Zhang ◽  
Hong Han ◽  
Jingxia Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Dynamic Range ◽  
Chaotic Signal ◽  
Coaxial Cable ◽  
Probe Signal ◽  
Echo Signal ◽  
Robust Performance ◽  
Range Resolution ◽  
System A ◽  
Before And After

A high-resolution leaky coaxial cable (LCX) sensor for perimeter intrusion detection is proposed and experimentally demonstrated. In our proposed sensor system, a wideband Boolean-chaos signal is used as the probe signal, and a pair of leaky coaxial cables (LCXs) is applied for transmitting the probe signal and receiving the echo signal, respectively. By correlating the chaotic echo signal with its delayed duplicate and comparing the correlation traces before and after intrusion, the intruder can be accurately located. Experimental results demonstrate the proposed sensor can simultaneously detect multiple intruders. The range resolution reaches 30 cm, whilst the dynamic range can achieve 50 dB. In addition, this sensor possesses the excellent anti-interference performance to the noise and uncorrelated chaotic signal, which makes it show robust performance in the detection environment with noise or multiple chaotic LCX sensors cooperation.

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