In recent years, with the rapid development of IoT sensing technology, the perimeter alarm products have developed rapidly, and electronic fences and vibrating optical fibers have gradually become the mainstream product pattern. Among them, the vibration optical fiber system uses a vibration sensing optical cable as a detection sensor. Because of its flexible cable shape and passive characteristics, it is particularly suitable for complex terrain, flammable and explosive, large electromagnetic interference, irregular perimeters, long protection distances, The use of project sites with alarm functions and beautiful features has become one of the perimeter alarm products favored by the market.
入侵探测器技术现状分析 Analysis on the Status Quo of Regional Vibration Fiber Optic Intrusion Detectors
入侵探测器和定位型振动光纤入侵探测器两大类，两者在前端入侵探测原理上稍有差别，但关键技术发展方向明显不一。 At present, vibratory optical fiber products are mainly divided into two types: regional (defense type) vibratory optical fiber intrusion detectors and positioning-type vibratory optical fiber intrusion detectors. The two have slightly different principles in front-end intrusion detection, but the key technology development direction is obviously One. 入侵探测器技术尚处于探索阶段，后端算法尚不完善，因此，本文着重关注已基本成熟的区域型振动光纤入侵探测器产品技术。 Because the positioning type vibration optical fiber intrusion detector technology is still in the exploratory stage and the back-end algorithm is not perfect, this article focuses on the mature regional vibration fiber intrusion detector product technology.
入侵探测器主要运用“光弹效应”的机理，并以极高的灵敏度探测外界的扰动。 The area-type vibration optical fiber intrusion detector mainly uses the "photoelastic effect" mechanism and detects external disturbances with extremely high sensitivity. Specifically, in the absence of external interference, the laser signal is transmitted according to a regular propagation path, and the system operates normally; and when external disturbance is used on the optical cable, it will cause changes in the parameters such as the optical phase and wavelength of the transmitted optical cable, and The system obtains vibration information after collecting and analyzing the change amount through photoelectric conversion, so as to determine whether an intrusion behavior has occurred.
1 外界扰动对光传输的影响 Figure 1 Influence of external disturbances on optical transmission
入侵探测器工作原理不难看出，作为探测单元，传感光纤需兼具极高的灵敏度，则可有效探测到各类入侵行为。 It is not difficult to see from the working principle of the area-type vibration optical fiber intrusion detector. As a detection unit, the sensing fiber needs to have both extremely high sensitivity, and it can effectively detect various intrusion behaviors. However, it has been proved in practice that, at the same time when high sensitivity is achieved, some manufacturers lack technical strength, which also leads to high sensitivity and high false positives. 入侵探测器产品漏误报率高是多种因素共同造成的结果。 Of course, the high false alarm rate of some regional vibration optical fiber intrusion detector products is the result of a variety of factors. How to innovate the current technology, while maintaining its high-sensitivity detection and effectively reducing the false alarm rate, has become a problem for most manufacturers.
How do the four key factors resolve false positives?
入侵探测器误报率高是技术表象，内里实则与产品无法精确区分干扰信号与入侵信号相关，结合其工作原理，探测光源、光路结构、频谱分析、智能算法成为影响系统准确区分信号的四大关键性因素，从中也可窥探缘何大部分区域型振动光纤入侵探测器产品漏误报率高的原因。 High sensitivity leads to high false alarm rate of regional vibration optical fiber intrusion detectors. It is a technical manifestation. It is actually related to the inability of the product to accurately distinguish the interference signal and the intrusion signal. Based on its working principle, the detection of light sources, optical path structures, spectrum analysis, and intelligent algorithms have affected The system accurately distinguishes the four key factors of the signal, from which the reasons for the high false alarm rate of most regional vibration fiber intrusion detector products can also be gleaned.
2 振动光纤入侵探测器四大关键性因素 Figure 2 Four key factors of vibrating fiber intrusion detector
入侵探测器核心性能 · Core performance of the area-type vibration fiber intrusion detector
入侵探测器核心性能的关键因素之一，在源头处收集信号时，既可精确收集完整信号又初步区分识别信号，可辅助后端更为精准区分干扰信号与入侵信号。 The experiment proves that the detection light source is one of the key factors determining the core performance of the area-type vibration fiber intrusion detector. When collecting signals at the source, both the complete signal can be accurately collected and the identification signal can be initially distinguished, which can help the back end to distinguish the interference more accurately. Signals and intrusion signals. At present, most of the products on the market have a narrow technical concept, ignore the front-end product selection, and use ordinary light sources to interfere at the front end. In fact, the combination of the front-end product selection of the manufacturer and its own technology has a huge impact on product performance. Generally, a common centimeter-level line-width light source with a cost of several hundred yuan has little phase difference after optical fiber interference. There is no doubt that this low-cost line-width light source cannot collect complete signals at all. The response to intrusion signals is not sensitive, and it is impossible to distinguish between interference signals and intrusion signals in a strong storm and rain, and the product cannot be used normally and stably. F5 系列分布式多防区振动光纤的探测光源采用造价高的窄线宽激光光源，线宽窄，接收到的信号特征更明显，干扰信号和入侵信号的区别更大，可明显区分。 Guangtuo F5 series distributed multi-zone vibration optical fiber detection light source uses a costly narrow linewidth laser light source. The linewidth is narrow, the characteristics of the received signal are more obvious, and the difference between the interference signal and the intrusion signal is larger, which can be clearly distinguished. While collecting signals at the source, it pays more attention to the identification of disturbance information waveforms. Its coherence length is several hundred times that of ordinary light sources, which not only extends the sensing distance, but also improves the signal-to-noise ratio. It is more comprehensive and accurate from the source. Collect and analyze signal waveforms, and work with intelligent algorithms to greatly reduce false alarms.
· Continuous innovation and improvement of light path structure
入侵探测器主要采用两种光路结构（光纤光栅已逐步被淘汰）：马赫增德尔（ MZ ）、萨格纳克（ Sagnac ），不同的光路结构，信号响应灵敏度明显不同，直接影响着产品可适用的安装环境和安装形式。 At present, there are mainly two types of optical path structures in the market (zone-type) vibrating fiber intrusion detectors (fiber gratings have been gradually phased out): Mach-Zehnder ( MZ ), Sagnac , different optical path structures, The signal response sensitivity is obviously different, which directly affects the applicable installation environment and installation form of the product. In addition, in the perimeter defense zone of tens of kilometers and long-distance detection, the optical path structure will also affect the optical transmission loss, resulting in damage to the transmission of alarm signals, resulting in missed reports. At present, each of the above two types of optical path structures has advantages and disadvantages. It is also necessary to enhance strengths and avoid weaknesses, and intensify improvement and innovation. F5 创新性改进马赫增德尔（ MZ ）光路结构，进一步提高系统对振动信号响应的灵敏度，搭配窄线宽激光光源，有效支撑 F5 在挂墙、嵌墙、埋地安装环境下报警性能依然稳定。 Guangtuo F5 innovatively improves the Mach Zundel ( MZ ) optical path structure, further improving the system's sensitivity to the vibration signal response, and with a narrow linewidth laser light source, it effectively supports the F5's alarm performance in wall-mounted, recessed and buried installation environments. stable. Innovative optical path detection technology, in principle, solves the problem of instability of interference signals caused by insensitivity to ambient temperature, polarization change, and phase change, which minimizes optical loss. At the end zone of long-distance detection, alarm signal transmission is strong. It will not cause false alarms, and because of its high temperature resistance and corrosion resistance, it is not affected by various harsh weather environments, and its system reliability and stability are also very strong.
+ 智能算法强强联合 · Back-end intelligent spectrum analysis + intelligent algorithm combination
光纤入侵探测器安装的环境往往极具复杂性，与人为因素、环境干扰因素相关的情况十分复杂，因此单一维度的数据绝不可能精准分析出入侵与干扰信号，多维度的频谱分析技术与智能算法是目前最为可行的处理方法。 The environment in which a vibrating fiber intrusion detector is installed is often extremely complicated, and the situation related to human factors and environmental interference factors is very complicated. Therefore, it is impossible to accurately analyze the intrusion and interference signals from a single dimension of data. Multi-dimensional spectrum analysis technology and Intelligent algorithms are currently the most feasible processing method.
F5 首创全频谱分析技术，运用高、中、低全频谱分析技术，从三个维度全面分析振动信号，即便是在七级风环境下有入侵行为，也可直观区分入侵信号和干扰信号。 In complex environments, F5 pioneered full-spectrum analysis technology, using high-, medium-, and low-full-spectrum analysis technology to comprehensively analyze vibration signals from three dimensions. Even if there is intrusion behavior in the seventh-level wind environment, the intrusion signals can be visually distinguished. And interference signals. Specifically, for the vibration caused by external interference (wind, rain, small animals, etc.), the most intuitive response in the frequency domain is that the frequency response is concentrated in the low frequency part, and the frequency response caused by the actual invasion action is concentrated in the high frequency part, and then combined Other processing analysis can accurately identify intrusion events and improve alarm accuracy.
Waveform graphs under seven-level wind to visually distinguish disturbance signals
F5 振动光纤系统模拟海量环境干扰信号特征，建立模型数据库，当存在风、雨、雪、车辆经过、小动物等一系列可能出现的干扰信号时，智能算法全方位地融合多种算法，系统自动匹配数据模型调节动态阈值，有效区分出周边干扰信号，辨别是否有入侵行为，极大地减少漏误报率，这也是其它厂商在降低产品漏误报率上很难实现的客观技术实力因素。 Combined with the signal sources in tens of thousands of actual cases, the F5 vibration optical fiber system simulates the characteristics of massive environmental interference signals and establishes a model database. When there are a series of possible interference signals such as wind, rain, snow, vehicles passing, small animals, etc., intelligent algorithms Integrate a variety of algorithms in all directions, the system automatically matches the data model to adjust the dynamic threshold, effectively distinguish the surrounding interference signals, identify whether there is intrusion behavior, and greatly reduce the false alarm rate. This is also the other manufacturers in reducing product false alarm rate Objective technical strength factors that are difficult to achieve.
1 F5 与其它区域型光纤振动入侵探测器产品对比 Table 1 Comparison of F5 and other regional fiber-optic vibration intrusion detector products
The key factor
分布式多防区振动光纤 F5 distributed multi-zone vibration fiber
光纤 Other manufacturers' regional vibration fiber Intrusion detector products
Laser light source
，相干长度长 Narrow linewidth laser light source with long coherence length
Common cm-level line-width light source with short coherence length
Light path structure
MZ ）光路结构 Innovative and improved Mach-Zehnder ( MZ ) optical path structure
High sensitivity and good frequency response
sagnac ） Sagnac
Poor sensitivity and low frequency response
Multi-channel high-speed parallel acquisition
数据无丢失 Real-time response without data loss
Low-speed serial polling
Slow response and easy data loss
，智能过滤 Full frequency domain algorithm , intelligent filtering
Time domain algorithm or low frequency algorithm, can not effectively filter environmental interference
Diversity and expansion
Video linkage, external sound and light module access platform is easy to expand and network
Single alarm output
单个防区可达 2km Longer zones, up to 2km for a single zone
1km 以内 Within a single zone length of 1km
光纤入侵探测器因其无可比拟的优势，极具实用价值和推广前景，然区域型振动光纤入侵探测器产品技术也需持续升级和突破， F5 从前端探测传感器到后端智能算法，在各个关键因素上逐一突破，既保留了振动光纤入侵探测器的高灵敏度探测，又将漏误报率降到最低，无疑改善了用户体验，扩大了产品应用市场。 It is undeniable that because of its incomparable advantages, the regional vibration optical fiber intrusion detector has great practical value and promotion prospects. However, the technology of the regional vibration optical fiber intrusion detector also needs to be continuously upgraded and breakthrough. F5 from the front-end detection sensor to the rear The intelligent algorithm at the end of the chip breaks through each of the key factors one by one. It not only retains the high-sensitivity detection of the vibrating fiber intrusion detector, but also minimizes the rate of false alarms, which undoubtedly improves the user experience and expands the product application market.
With the continuous development of the Internet of Things technology and the construction of future cities, the industrialization process of the two types of optical fiber vibration intrusion detector products will gradually accelerate, and the application sites will continue to be improved. Market demand has raised higher product functions and stability. Requirements, such as achieving a larger detection range, higher response bandwidth, carrying more zones, and more accurate zone positioning, are expected to continue to explore for vibrating fiber manufacturers.
、 脉冲电子围栏 、 张力电子围栏 Electronic fence , pulse electronic fence , tension electronic fence 报警主机 、 室内报警 、 智慧社区 系统尽在上海广拓，广拓一直致力于用技术的进步创造安全的环境。 , Vibration optical fiber , security management platform , alarm host , indoor alarm , smart community system are all in Shanghai Guangtuo. Guangtuo has been committed to creating a safe environment with technological advancement.