CAJ | 학술논문

为降低结构健康监测加速度信号中常见的白噪声以及脉冲噪声,提出了中值滤波与小波阈值降噪相结合的方法.分解层数对降噪效果有着重要影响,为取得更好的降噪效果,提出一种分解层数自适应确定法,并给出了各层阈值的取值方法.数值模拟以及国家游泳中心健康监测系统实测数据分析结果表明,所提出的方法克服了传统阈值降噪法对脉冲噪声拟制效果不理想的缺陷,能同时有效降低白噪声以及脉冲噪声,为模态参数识别等提供更高信噪比的分析数据.
위강저결구건강감측가속도신호중상견적백조성이급맥충조성,제출료중치려파여소파역치강조상결합적방법.분해층수대강조효과유착중요영향,위취득경호적강조효과,제출일충분해층수자괄응학정법,병급출료각층역치적취치방법.수치모의이급국가유영중심건강감측계통실측수거분석결과표명,소제출적방법극복료전통역치강조법대맥충조성의제효과불이상적결함,능동시유효강저백조성이급맥충조성,위모태삼수식별등제공경고신조비적분석수거.
In order to reduce the white noise and pulse noise in the acceleration signal of civil structural health monitoring,a combinative method of medial filter and wavelet threshold was proposed. Because of that the level decomposition has a significant impact on the result of denoising,in order to get better result,a self-adaptive method to select the decomposition level was proposed. The method to determine the value of threshold at each level was also given out. The analysis of numerical simulation result and the on-site measured data by use of the structural health monitoring system of National Aquatics Center in Beijing 2008 Olympic venues shows that,the method proposed in the paper can overcome the defect of the wave threshold method which doesn't have obvious effect to reduce the pulse noise. It can reduce the white noise and pulse noise at the same time and provide data of higher signal to noise ratio for modal parameter identification and so on.