Faculty of Mechanical Engineering and Robotics, AGH University of Science and Technology, 30 Mickiewicza Avenue, 30-059 Krakow, Poland.
Sensors (Basel). 2019 Jan 10;19(2):255. doi: 10.3390/s19020255.
Measurements of deformations by means of vibrating wire sensors are very important in the monitoring of building structures. These types of sensors are characterized by a high resistance to environmental conditions, long time of measurement stability, and a possibility to use long electric cables with a solid encasement in concrete. Vibrating wire sensors are mainly used for measuring stable or slowly changing deformations, however applications of these sensors for measuring time-variable deformations are becoming popular. New solutions generate new problems, which in case of vibrating wire sensors are mainly related to the operational stability of the systems exciting wire vibrations. The structure of such sensors and the length of the electric cables, which can reach a few kilometers, have an essential influence on their operations. This paper undertakes the task of determining the influence of the electric cables length on the proper operation of the measurement system and provides advice for improvements of its measurement possibilities. The subject of investigation constitutes a measurement system based on a self-exciting impulse exciter, for which the impedance of the electric cables and of the vibrating wire sensor are the most essential parameters. A mathematical model of this system, experimental verification of the model, and the results of theoretical analyses and measurement tests for electric cables of various lengths are presented in this paper.
利用振弦式传感器测量变形在建筑物结构监测中非常重要。这些类型的传感器具有耐环境条件、长时间测量稳定性以及使用带有固体外壳的长电缆在混凝土中进行测量的可能性等特点。振弦式传感器主要用于测量稳定或缓慢变化的变形，但是这些传感器用于测量时变变形的应用越来越受欢迎。新的解决方案会产生新的问题，对于振弦式传感器而言，这些问题主要与激励钢丝振动的系统的运行稳定性有关。这些传感器的结构和可达数公里长的电缆长度对其运行有重要影响。本文旨在确定电缆长度对测量系统正常运行的影响，并为提高其测量能力提供建议。研究的主题是基于自激脉冲激励器的测量系统，对于该系统，电缆和振弦式传感器的阻抗是最重要的参数。本文介绍了该系统的数学模型、模型的实验验证，以及对不同长度电缆的理论分析和测量测试结果。
