基于光纤惯性传感的桥梁结构线形测量方法的研究

发布时间：2018-04-30 08:45

本文选题：桥梁结构 + 线形测量　；参考：《武汉理工大学》2014年博士论文

【摘要】：桥梁是国家交通运输的重要基础设施。根据我国《公路桥梁技术状况评定标准》与《公路桥梁承载能力检测评定规程》等相关行业规范，桥梁结构的几何线形是评价桥梁安全状况最重要的参量之一，通过对桥梁结构几何形态的线形测量，可反演出桥梁结构的内力变化情况，为分析桥梁的安全状态提供可靠依据。我国桥梁数量众多，，目前桥梁结构几何线形的测量是通过经纬仪、水准仪、全站仪等工程测量仪器完成的。这种测量方法虽然测量精度较高，但需要设定永久基准点、架设仪器、确定测量点等，测量步骤十分繁琐。因此该测量方法工作周期长、耗时费力，无法满足数量庞大的中小型桥梁结构安全检测的应用需求。GPS测量方法虽然可以实现快速的结构线形测量，但是测量精度不高，且易受拉索及桥塔的干扰。由此可见，开发与研究一种高效率的桥梁结构几何线形测量新方法，快速、准确的测量桥梁结构形变位置与形变量，实现桥梁结构的安全检测，成为一个紧迫而又极具挑战的研究课题，具有重大的研究意义和开发价值。在惯性导航技术领域中，惯性仪表可以准确测量运载体的运动参数，获取运载体的运动轨迹曲线。根据这一特点，可利用光纤惯性传感技术对桥梁结构的几何线形进行测量。然而，对比惯性导航领域，光纤惯性传感技术的应用环境发生了很大变化。一、惯性导航的测量距离较长，达到几十公里甚至上万公里，而桥梁结构待测线形的距离相对较短。二、惯性导航系统的运行线速度非常快，而桥梁结构线形测量对线速度的要求不高，测量速度相对较慢。三、惯性导航的运行轨迹是一个随机、不可重复的路线，而桥梁结构的线形是一个固定不变的曲线，可以进行重复测量。由此可见，在桥梁结构线形测量这个特殊应用领域中，光纤惯性传感技术的应用方式存在着较大差异，并提出了新的技术要求。为检测桥梁结构的安全状况，桥梁结构几何线形的测量精度需要达到毫米级甚至毫米级以下，而惯性导航则难以达到如此高的绝对测量精度。因此本文的研究重点是利用光纤惯性传感技术，设计一种线形测量方法，实现短距离、固定曲线的高精度测量，并将其应用于桥梁结构几何线形的测量，以此检测桥梁结构的健康安全状况。本论文的主要工作内容如下：一、通过对现有桥梁结构线形测量方法的概述与分析，讨论其目前存在的问题。研究采用光纤惯性传感技术对桥梁结构的几何线形进行测量，解决当前桥梁结构线形测量所面对的难题。二、研究光纤惯性传感技术应用于桥梁结构线形测量的原理，以此为理论基础，确定测量方法中运载体运动参数的采集方式，构建线形测量系统。利用该测量系统进行实际的线形测量，得到初步的线形测量结果。该测量结果的误差较大，且具有发散的特性。为降低线形测量误差，分析该发散性误差产生的原因。该测量误差主要来自于系统内部因素与外界应用环境因素的共同影响，以此为依据确定了光纤惯性传感技术应用于桥梁结构线形测量需要处理的关键性技术难点。三、研究系统自身因素对光纤惯性传感线形测量系统的影响，确定这些内部影响因素主要是由FOG的自身固有特性和运载体的运动方式所决定的。研究采用多种方法处理FOG相关特性对线形测量结果的影响，并采用适当的运载体运动方式获取准确的运动参数测量值，从源头上遏制测量误差的发散性。四、研究外界应用环境因素对光纤惯性传感线形测量系统的影响。这些外界影响因素主要是由于桥面的不平整所造成的，导致运载体在测量过程中会受到振动与冲击的影响，使测量信号包含有较大的噪声误差。研究这两种不同的外界激励方式对测量结果带来的影响，并根据不同的响应机理，采用不同的方式处理振动与冲击所造成的噪声误差，提高线形测量信号的信噪比，降低对线形测量系统的影响。五、利用桥梁结构的几何线形是一段短距离、固定的曲线这一特点，设计采用坐标变换、固定点曲线拟合、标定物误差修正、数理统计计算等方法对线形测量结果的误差进行处理，同时处理了地球曲率对测量结果的影响。这些误差处理方法大幅降低了测量误差，提高了线形测量结果的精度，使其达到毫米级以下，满足桥梁结构安全检测的精度要求。六、研究讨论了基于光纤惯性传感的桥梁结构线形测量方法的应用方式。通过对桥梁结构的几何线形进行测量，分析测量结果，研究桥梁结构的形变位置与形变量，确定桥梁结构的下挠是否超过了限值，以此检测桥梁结构的安全状况。通过对荷载前后桥梁结构线形测量结果的分析，评估桥梁结构的强度、刚度、稳定性与耐久性，以检测其健康安全状态。根据这两种检测方法的实际应用效果可以看出，基于光纤惯性传感的桥梁结构线形测量方法能够检测桥梁结构的健康安全状况，相比较于其他的测量方法具有巨大的应用优势。通过本文的研究，基于光纤惯性传感的桥梁结构线形测量方法测量速度快、精度高、重复性好、可靠性高、不需要封桥测量、不需要设立和保护永久基准点。因此，具有广阔的应用前景。
[Abstract]:Bridge is an important infrastructure for national traffic and transportation. According to the standards for evaluation of technical status of highway bridges and the regulations for evaluation of bearing capacity of road and bridge, the geometric alignment of bridge structure is one of the most important parameters for evaluating the safety of bridges, through the linear measurement of the geometric shape of the bridge structure, The internal force of bridge structure is changed to provide reliable basis for analyzing the safety state of bridge.
There are a large number of bridges in our country. At present, the measurement of geometric alignment of the bridge structure is accomplished by the engineering measuring instruments such as theodolite, leveling instrument, total station and so on. Although the measurement accuracy is high, it is necessary to set the permanent datum point, set up the instrument, determine the measuring point and so on. The measurement procedure is very complicated. Therefore, the measurement method is very complicated. Therefore, the measurement method is very complicated. Therefore, the measurement method is very complicated. Therefore, the measurement method is very complicated. Therefore, the measurement method is very complicated. Long, time-consuming and time-consuming, it is unable to meet the requirements of the large number of small and medium bridge structures. Although the.GPS measurement method can achieve rapid structural linear measurement, the measurement accuracy is not high, and it is easy to be disturbed by the cable and the bridge tower. Thus, a new method of geometric linear measurement for the bridge structure is developed and studied. It is an urgent and challenging research topic to measure the deformation position and variable of the bridge structure quickly and accurately, and to realize the safety detection of the bridge structure. It has great significance and value for development.
In the field of inertial navigation, inertial instruments can accurately measure the motion parameters of the carrier and obtain the trajectory curve of the carrier. According to this characteristic, the geometrical line of the bridge structure can be measured by the optical fiber inertial sensing technology. However, the application environment of the inertial navigation domain is compared with the inertial navigation domain, and the application environment of the optical fiber inertial sensing technology has occurred. A great change.
First, the distance measured by inertial navigation is longer, reaching tens of kilometers or even tens of thousands of kilometers, while the distance of bridge structure to be measured is relatively short.
Two, the speed of inertial navigation system is very fast, while the linear measurement of bridge structure is not very fast and the measurement speed is relatively slow.
Three, the track of inertial navigation is a random and non repeatable route, and the alignment of bridge structure is a fixed curve, which can be repeated measurements.
Thus, in the special application field of linear measurement of bridge structure, there are great differences in the application mode of optical fiber inertial sensing technology, and new technical requirements are put forward.
In order to detect the safety of the bridge structure, the measurement accuracy of the geometric alignment of the bridge structure needs to be below millimeter or even millimeter, while the inertial navigation is difficult to achieve such high absolute measurement accuracy. Therefore, the focus of this paper is to use the optical fiber inertial sensing technology to design a linear measurement method to achieve short distance and fixed curve. The high-precision measurement of the line is applied to the measurement of the geometric alignment of the bridge structure, so as to detect the health and safety of the bridge structure.
The main contents of this paper are as follows:
First, through the overview and analysis of the existing bridge structural linear measurement methods, the existing problems are discussed. The study of the geometrical alignment of the bridge structure by optical fiber inertial sensing technology is used to solve the problems faced by the current bridge structure alignment measurement.
Two, the principle of optical fiber inertial sensing technology applied to the linear measurement of bridge structure is studied. Based on this theory, the acquisition mode of carrier motion parameters in the measurement method is determined and a linear measurement system is constructed. The actual linear measurement is carried out by the measurement system, and the preliminary linear measurement results are obtained. The error of the measurement results is large, and In order to reduce the linear measurement error and analyze the cause of the divergence error, the measurement error mainly comes from the common influence of the internal factors of the system and the external application environment factors. On this basis, the key technical difficulties in the application of optical fiber inertial sensing technology to the linear measurement of the bridge structure are determined.
Three, the influence of the system's own factors on the optical fiber inertial sensor linear measurement system is studied, and the main factors are determined mainly by the inherent characteristics of FOG and the movement mode of the carrier. Many methods are used to deal with the influence of FOG related characteristics on the linear measurement results, and the proper movement mode of the carrier body is adopted. Obtain accurate measurement parameters of motion parameters and restrain divergence of measurement error from source.
Four, the influence of the external environmental factors on the optical fiber inertial sensor linear measurement system is studied. These external factors are mainly caused by the uneven deck of the bridge, which lead to the influence of the vibration and impact of the carrier in the measurement process, and make the measurement signal contain a larger noise error. Study the two different external excitation. According to the different response mechanism, the noise error caused by vibration and shock is handled in different ways, and the signal to noise ratio of the linear measurement signal is improved and the influence on the linear measurement system is reduced.
Five, the geometric alignment of the bridge structure is a short distance and a fixed curve. The design adopts coordinate transformation, fixed point curve fitting, calibration error correction, mathematical statistics calculation and other methods to deal with the error of linear measurement results. At the same time, the influence of earth ball curvature on the measurement results is dealt with. These error treatment methods are dealt with. The measurement error is greatly reduced, the accuracy of alignment measurement is improved, and it reaches below millimeter level, which meets the accuracy requirement of bridge structure safety inspection.
Six, the application mode of the linear measurement method of bridge structure based on optical fiber inertial sensor is discussed and discussed. By measuring the geometric alignment of the bridge structure, analyzing the measurement results, studying the deformation position and shape variables of the bridge structure, determining whether the deflection of the bridge structure exceeds the limit value, so as to detect the safety status of the bridge structure. Through the analysis of the linear measurement results of bridge structure before and after the load, the strength, stiffness, stability and durability of the bridge structures are evaluated to detect their health and safety. According to the practical application results of these two methods, the bridge structure measurement method based on optical fiber inertial sensing can be used to detect the health of bridge structures. The security situation has great application advantages compared with other measurement methods.
Through the study of this paper, the linear measurement method of bridge structure based on optical fiber inertial sensor has high speed, high precision, good repeatability and high reliability. It does not need to seal bridge measurement, and does not need to set up and protect permanent datum points. Therefore, it has a broad application prospect.

【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U446

【参考文献】