Research on human intruder detection and localization based on LCX sensor

Abstract

Many aspects of the intruder detection system (IDS) based on the LCX sensor are still unknown due to its complex propagation characteristics. In order to study the field disturbance mechanism of human intruder and to reduce the phase error caused by the initial state of the detection signal, a novel method of improving the localization accuracy is proposed. At the frequencies of 40, 100, and 200 MHz, the IDS based on the LCX sensor is proposed by analyzing the scattering characteristics of the radar cross section (RCS) of human intruder and using IQ demodulation method. According to the characteristics of the IDS, the RCS is obtained by irradiating the human intruder from three typical radiation directions, which are front, side, and low-side direction in the mentioned frequency range. Combined with the method of pulse accumulation and synchronous subtraction, the intruder localization can be easily realized by using pulse delay positioning method. The results demonstrate the improvement in localization accuracy and the decrement in false positive rate, and the positioning error is less than 1 m.intruder detection, LCX sensor, localization, pulse accumulation, synchronous subtraction, phase errorAs a kind of receiving and emitting device, leaky coaxial cable (LCX) has been intensively used for various application scenarios, such as tunnel, railway, indoor communication, and positioning localization system. 1-5 The perimeter intrusion detection system (IDS) based on the LCX sensor has been widely studied because of its better concealment, flexible installation, and all-weather conditions work. 6,7 The ordinary localization systems usually detect the target in the area of directional beam of the systems' antennas.However, the IDS based on LCX sensor has completely different characteristics. The apertures on the LCX are similar to the array antennas, 8,9 which builds a wide-belt flexible detection area instead of the area of directional beam. The closer the distance between the aperture and the intruder, the more obvious reflection effect the aperture provides. The IDS can avoid the influence of the environment and the terrain. Because most of the power is transmitted in the LCX sensor, the IDS can reach a far distance to achieve the security guarding with the small attenuation in a specific area.Although some IDS based on LCX sensor have been applied, on the one hand, there are few articles discussing the theoretical analysis or mathematical calculation of the electromagnetic disturbance mechanism of the human intruders; on the other hand, with the development of science and technology, there is an urgent need to deal with the IQ-demodulation echo signal with the new method. Based on the results of radar cross section (RCS) calculations, the disturbing mechanism of human intruder is analyzed in this article. The experiments in time-domain and frequency-domain echo signals are carried out in the radiation mode and coupling mode. Moreover, the experiment of the signal receiver unit of IDS is conducted by means of the...

A Combined Sensing System for Intrusion Detection Using Anti-Jamming Random Code Signals

“…The common intrusion detection technologies include infrared sensors [1,2], video surveillance systems [3,4], electronic fences [5][6][7], vibration cable transducers [8], optical fiber vibration sensors [9][10][11][12], leaky coaxial cable (LCX) sensors [13][14][15][16][17][18][19][20], and radar sensors [21][22][23][24][25].…”

“…The previous continuous-wave LCX sensor determines that the intruder is present along the LCXs but is unable to locate the intruder within the LCX length [13]. In recent developments, the single frequency pulse [14,15], linear frequency modulation pulse [16,17], and binary phase shift keying pulse [18] have been used as the detection signals of LCX sensors, respectively. The delay time of the above pulse echoing from the intruder is obtained by pulse compression and synchronous subtraction.…”

Field scattering localization based on compressed sensing

“…Wireless localization has aroused huge attention recently as it is employed extensively 1‐3 . In Reference 4, the problems existing in indoor sound source localization with the use of a wireless acoustic sensor network were addressed, and a novel sparse Bayesian learning‐based algorithm was proposed.…”

A LCX-Based Intrusion-Detection Sensor Using a Broadband Noise Signal

“…The sensor can judge whether there exists an intruder by comparing the echo waveforms before and after intrusion, but it cannot give an accurate intrusion distance [22]. By transmitting a RF pulse such as a 1/2 sine pulse [15], a single-frequency pulse [16], a linear frequency modulation (LFM) pulse [17], and a chirp signal [18], the LCX-based sensor can locate the intruder with the location accuracy less than 1 m. It is realized by calculating the delay time of echo pulse after the pulse accumulation and the synchronous subtraction. However, its range resolution can only reach several meters, such as 6.64-m range resolution given by [17] and 3.32-m range resolution reported in [18].…”