基于线调频小波积分的时变系统物理参数识别  

Physical parametric identification of time-varying system based onchirp wavelet integration

作　　者：张杰[1] 史治宇[1] 赵宗爽 ZHANG Jie;SHI Zhiyu;ZHAO Zongshuang(State Key Lab of Mechanics and Control of Mechanical Structures,College of Aeronautics,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学航空学院机械结构力学及控制国家重点实验室,南京210016

出　　处：《振动与冲击》2020年第21期267-273,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(11172131;11232007)。

摘　　要：基于短时线性变化假设推导了线调频小波积分计算方法。借助此方法仅利用时变结构的加速度响应信号,就可重构出速度响应和位移响应信号,并在质量参数已知的情况下构造最小二乘算法识别结构的时变刚度和时变阻尼。由于引入了调频斜率参数刻画信号的短时调频特征,该方法相比传统识别方法能更好地追踪快速时变参数且计算效率大大提高。仿真算例中,构造了一个3自由度时变结构模型,针对各种时变情况进行物理参数的识别,验证了方法的正确性、适用性和抗噪声能力。A method of chirp wavelet integration was derived based on the short-time linear change assumption.Applying this method, velocity and displacement response signals of a time-varying structure were reconstructed only with its acceleration response signal. Then, time-varying stiffness and damping of the structure were identified by constructing a least squares algorithm when the structure’s mass parameters were known in advance. It was shown that due to introducing frequency modulation slope parameter to characterize the short-term frequency modulation characteristics of a signal, compared with the traditional identification method, this method can better track fast time-varying parameters and greatly improve computational efficiency. In a simulation example, a 3-DOF time-varying structure model was constructed, and its physical parameters were identified under various time-varying conditions to verify the correctness, applicability and anti-noise ability of the proposed method.

关 键 词：时变系统 参数识别 线调频小波积分 加速度响应 信号重构 

分 类 号：O324[理学—一般力学与力学基础] TB123[理学—力学]