Low-power consumption vibrating wire sensor and excitation detection method thereof

Abstract

The invention discloses a low-power consumption vibrating wire sensor. The low-power consumption vibrating wire sensor comprises a vibrating wire, a coil, a sensor housing, an excitation circuit unit, a vibration picking circuit unit and a main control unit. The main control unit comprises a pre-vibration module, a complex-vibration module, a frequency detection module and a signal processing module. The signal processing module records effective complex-vibration efficiency signals, controls excitation detection processes of the sensor so as to allow the sensor to work in steady-state and non-steady state modes, and calculates an excitation frequency value output by the complex-vibration module in the steady-state working mode according to recorded effective complex-vibration frequency value. According to the invention, by changing excitation modes of the vibrating wire, changing a traditional low-voltage sweep-frequency excitation mode into an excitation mode combining pre-vibration and complex-vibration, and using a frequency value during pre-vibration detection as the excitation pulse frequency of the re-vibration, an energy saving effect is achieved.

Description

technical field [0001] The invention belongs to the technical field of sensors, in particular to a vibrating wire sensor used for displacement or deformation measurement of structures. Background technique [0002] In the daily maintenance of large structures, it is very important to measure the deformation or displacement of its key components. The stress magnitude and distribution changes of the above-mentioned stressed components most directly reflect the health of the structure. Therefore, the stress status monitoring of these components And the safety analysis and evaluation based on this is of great significance. [0003] At present, the sensitive element of the vibrating wire sensor is a metal wire string, which is connected and fixed with the force-bearing part of the sensor. Various physical quantities are measured by using the relationship between the natural frequency of the steel string and the applied tension on the steel string. The vibrating wire sensor It is...

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Problems solved by technology

[0005] However, since the frequency sweep signal is a continuous pulse signal from the lower frequency limit to the upper frequency limit, in order to ensure the excitation effect, the pulse of each frequency must last for several cycles, and the excitation time is too long, resulting in high energy consumption, which limits the sensor In the application of remote unattended measurement system, in order to improve the battery life and save energy consumption, the electric excitation method of the vibrating wire sensor must be improved

[0006] In the "Journal of Sensor Technology", Volume 23, Issue 1, 2010, the article "Optimization of Vibrating Wire Sensor Vibration Strategy" discloses a vibrating wire sensor frequency detection scheme that combines initial measurement and retesting. The method first obtains an initial value of the vibration frequency, and then performs a second low-voltage string excitation with the initial value to obtain an accurate value. Although this program can obtain high measurement accuracy, it needs to be carried out twice each time. Encouragement and detection, the energy consumption is still high, so it is difficult to adapt to the unattended detection requirements in the field such as bridges in a slowly changing state

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