Multipoint displacement simultaneous measuring method

Abstract

The invention discloses a multipoint displacement simultaneous measuring method, and a measuring system is shown in the figure. A reference point transmitting antenna is installed on the fixing position, and the surface of the measured object is equipped with multiple observation point transmitting antennae; a public radio frequency local oscillator generates a radio frequency carrier signal, a reference point beacon receiver directly transmits the radio frequency carrier signal through the reference point transmitting antenna, an observation point beacon receiver uses a low frequency sine wave signal to perform the double-sideband modulation to the radio frequency carrier signal, and sends it to the observation point transmitting antennae; the frequency of the sine wave modulating signal of each observation point beacon receiver is different; after receiving the mixed signal transmitted by the reference point transmitting antenna and the observation point transmitting antennae, a telemetering receiver uses the other radio frequency local oscillator to convert the frequency of the signal to the intermediate frequency, and digitize it, and then perform the Fourier transform to obtain its magnitude spectrum and phase spectrum, so that the carrier phase difference of each observation point signal and the reference point signal is calculated; and according to the phase difference variation of two times of previous and next measurement, the displacement of each observation point is calculated.

Description

technical field [0001] The invention belongs to the field of structural health monitoring, and relates to a multi-point displacement simultaneous measurement method. Background technique [0002] Large components such as power towers, skyscrapers, bridges, dams, and large aircraft will deform during use. Deformation measurement is a basic method for exploring deformation mechanisms and an important means for early warning of danger. Patent CN1271419C and patent CN101349753A summarize and analyze several common measurement methods, and point out that radio frequency technology has many advantages in deformation measurement. [0003] Patent CN1271419C proposes a micro-displacement measurement method. The measurement system is composed of a passive corner reflector placed on the measured point and a microwave phase comparison device on the measured point. The displacement of the corner reflector is measured based on the phase difference between the microwave phase comparison d...

AI Technical Summary

Problems solved by technology

The main disadvantages of this method are: (1) the observation point is a passive corner reflector, and the operating distance is limited; (2) the signals of densely distributed passive corner reflectors are difficult to separate, and simultaneous measurement of multiple observation points cannot be realized

The main problem in the use of this method is that the circuit of the telemetry receiver is complex, and the circuit fails to work when the pseudo code is out of lock, and the displacement of each observation point cannot be measured.

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