针对多路振弦传感器测频系统多采用分时异步的测量方式,无法满足桥梁等大型建筑动态响应的测量需求,提出一种同时激振-分时测量的同步测量方案;根据该方案设计了一套多路振弦传感器同步测频系统.系统以Cortex-M4处理器为核心,采用Rife-Quinn算法进行频率计算.对系统进行实验测试,测试结果表明:系统能完成4通道振弦传感器的同步测量,无噪声条件下的测频相对误差小于0.007%;输入1 kHz、峰值为2 μV~3.4 mV范围的正弦信号,系统测频相对误差小于0.005%,标准差小于0.04 Hz;加入白噪声干扰,信噪比在-9~9 dB范围内,系统的测频相对误差小于或等于0.2%.%Multi-channel vibrating wire sensor frequency measurement system usually adopts the way of time -sharing asynchronous measurement,which can hardly meet the measurement needs of dynamic responses of bridges and other mega structures.In response to it, a set of multi-channel vibrating wire sensor synchronous frequency measurement system is developed on basis of a synchronous measurement method integrating simultaneous vibration and time-sharing measurement given in the chapter.Centering on Cortex-M4 processor,the system uses Rife-Quinn algorithm to figure out the frequency.Experimental test result of the system indicates that it can complete synchro-nous measurement of four-channel vibrating wire sensor,and its relative error of frequency measurement in noiseless condition is less than 0.007%;Input sinusoidal signal with a frequency of 1 kHz and a peak ranging from 2 μV to 3.4 mV,the system's relative error of frequency measurement is less than 0.005% and its standard deviation is less than 0.04 Hz;When white noise interference is imposed,the system's SNR ranges from -9 to 9 dB,and its relative error of frequency measurement is less than or equal to 0.2%.
展开▼
