Estimating Parameters of Linear Time Varying System using Chirplet Integration of Acceleration Response
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摘要: 提出了线调频小波积分运算方法,在仅获得加速度响应的情况下对结构速度和位移响应进行重构,将时变微分方程转化成区间线性方程组,进而构造最小二乘算法识别结构的时变物理参数。Chirplet基适用于处理时变信号,能在短区间拟合时变系统各阶响应,相比传统小波能更好地追踪信号频率变化特征,通过与微分方程结合提高了时变系统参数识别的效率。方法的有效性和适用性通过一个3自由度时变结构模型进行了验证。
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关键词:
- 线性时变系统 /
- Chirplet积分 /
- 加速度响应 /
- 物理参数识别
Abstract: This paperuses the Chirplet integration method totransform the time-varying differential equations into interval linear equations by reconstructing the structural velocity and displacement response when the acceleration response is measured. Then the physical parameters of the time-varyingsystem are identified based on the least squares algorithm. The Chirplet basis function is suitable for processing time-varying signals since it fits the time-varying system′s response in a short interval. Compared with the traditional wavelet, it tracks better the frequency variation of signals. It also improves the time-varying parameter identification efficiency by combining differential equations. The validity and applicability of the method is verified with a 3-DOF time-varying structure model. -
表 1 识别结果的误差分析
% 参数 SNR 无噪声 100 50 20 ${m_1}$ 3.380 3.381 3.727 4.427 ${m_2}$ 4.155 4.153 4.804 6.133 ${m_3}$ 3.172 3.172 3.390 4.025 ${k_1}$ 6.331 6.331 7.431 9.301 ${k_2}$ 6.026 6.026 7.069 8.032 ${k_3}$ 6.753 6.750 8.053 9.774 -
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