针对Android智能手机传感器默认采样模式存在的采样率设置固化、欠采样和过采样问题,开发了能够自定义采样率和采样精度,具有采样历元、时间间隔和数据等同步记录功能的手机传感器信号采集软件。模拟加速度信号的功率谱分析和位移积分重构研究表明,L-S谱分析法和频域位移积分法能够有效处理含噪声和非均匀采样的手机加速度信号。利用谷歌Nexus 5(NX 5)、小米3(Mi 3)两个Android手机和SPAN-IGM-A1惯性组合导航系统进行徐州汉桥加速度信号采集和振动检测对比试验,试验结果有效验证了便携式、低成本Android智能手机进行桥梁振动检测的可行性。
In view of the fixed sampling rate setting, the problems of under sampling and over sampling in the default sampling mode of Android smartphone sensors are discussed in this paper, and a smartphone sensor signal acquisition software with a custom sampling rate and sampling precision is deyeloped, which can synchronously record the data of the sampling epoch, the time interval and the sensor values. Then, both two power spectrum analysis methods and two displacement signal reconstruction methods of analog acceleration signals are compared and analyzed, and the results show that the L~S method and the frequency-domain integral method can effectively process the non-uniform sampling signal of smartphone sensors with noise. At the end, the acceleration signals of Xuzhou Han Bridge are collected from both smartphones (NX 5 and Mi 3) and a high precision inertial integrated navigation system (SPAN-IGM-Al) used for comparison experiments, and the bridge vibration detection and analysis results verify that the portable and low-cost Android smartphone can be used to conduct the bridge vibration detection.