Cable force dynamic tester based on modified FFT algorithm and algorithm thereof

Abstract

The invention relates to a cable force dynamic tester based on a modified FFT algorithm and an algorithm thereof, belonging to the technical field of civil engineering. The cable force dynamic tester and the algorithm are applied to the structure safety and health monitoring industry. The cable force dynamic tester comprises a vibration sensor, an anti-aliasing filter, an ADC converter, an embedded processor, a keyboard, an RTC real-time clock, a power supply management module, an LCD display and a DSP processor. The vibration sensor is connected to the anti-aliasing filter which is connected to the ADC converter, and the ADC converter is connected to the embedded processor. The keyboard, the RTC real-time clock, the LCD display and the DSP processor are connected to the embedded processor. According to the cable force dynamic tester and the algorithm, a modified FFT method is used, a precise actual frequency value is obtained, thus the frequency value precision of force value measurement is within 5 / 10000 through the modified FFT method, the frequency precision after conventional FFT calculation only reaches 2%, and the lower a frequency is, the larger an error is.

Description

technical field [0001] The invention relates to a cable force dynamic measuring instrument based on a modified FFT algorithm and an algorithm thereof, which belong to the field of civil engineering and are applied to the structural safety and health monitoring industry. Background technique [0002] Existing technology: Although the traditional cable force test system is sampled in the time domain and converted into the frequency domain by FFT, due to the limitation of the number of sampling points and the computing power of the equipment processor, the frequency accuracy cannot be obtained very high, and our The measured objects are all bridge cables, which belong to low-frequency signals. At this time, the frequency accuracy will have a great impact on the measurement accuracy, resulting in large errors in cable force measurement. [0003] For example, the frequency resolution formula Δf=SF / N of the traditional FFT calculation, where SF is the sampling rate, N is the numbe...

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Problems solved by technology

[0002] Existing technology: Although the traditional cable force test system is sampled in the time domain and converted into the frequency domain by FFT, due to the limitation of the number of sampling points and the computing power of the equipment processor, the frequency accuracy cannot be obtained very high, and our The measured objects are all bridge cables, which belong to low-frequency signals. At this time, the frequency accuracy will have a great impact on the measurement accuracy, resulting in a large error in cable force measurement.

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