基于趋势项误差控制的频域积分算法研究与应用

Integration algorithm based on trend-control of error in frequency domain

针对工程测试中利用振动加速度积分获得位移时出现严重趋势项误差问题,采用低频衰减算法对加速度信号在频率内直接积分,并利用积分精度控制方程保证积分精度。通过与积分算法比较及验证,证明该算法对积分误差控制具有一定优势。搭建含限位冲击的振动测试实验台,研究该算法在工程测试中应用特性。实验研究表明,该算法可有效控制趋势项误差,且随待积分加速度基频提高积分所得位移信号与真实位移信号吻合度提升。基于所用测试系统,加速度信号基频超过3.8 Hz时积分幅值误差小于10%,满足工程测试需要;加速度基频大于4.35 Hz时积分峰值误差小于5%,可获得较好测试效果。

The paper presents the results of an integration algorithm developed to reduce the trend of error that usually appears in the process of acceleration integration for displacement in engineering test.The integration of acceleration was conducted directly in frequency domain and the integral accuracy was governed by a controlling equation. Experiments were conducted to compare the integration algorithm with conventional methods and the results indicate that it is privileged to better control the trend of error.Vibration experiments with impact of limit displacement were introduced to investigate the characteristics of the integration algorithm.It＇s to be noted that the integral trend of error is reduced effectively by the integration algorithm,and it is decreasing with increasing acceleration baseband.The magnitude of integral error is less than 10% while the baseband of the acceleration signal exceeds 3.8 Hz and less than 5% while exceeds 4.35 Hz,which could satisfy the engineering requirements more effectively.