泵车疲劳损伤计算中的奇异值剔除方法

A Method of Removing Singular Values in Calculation of Fatigue Damage for Truck Mounted Concrete Pump

计算混凝土泵车臂架疲劳损伤时采集的应变数据中含有奇异值会对损伤结果产生较大影响,而传统的3σ准则的判定值为常系数,不适合泵车臂架应变信号的变化.对此,结合泵车臂架应变信号的特点,提出了剔除奇异值的新方法:变化率法,该方法利用应变信号的变化率是否超出随应变信号变化情况而定的剔值范围来进行奇异值的判定,并根据奇异值偏离正常范围的程度修正奇异值.详细阐述了变化率法并且利用Matlab进行了仿真验证.结果表明,变化率法在剔除应变信号孤立奇异值上比3σ准则更为有效,且变化率法剔除应变信号中连续个数不多的奇异值时效果也较好.

Singular values in strain data have a significant iMPact on the result when calculating fatigue damage for truck mounted concrete pump.However,the determining value of traditional 3σ-rule is a constant coefficient,which is not suitable for the variation of truck mounted concrete pump strain signal.Therefore,combined with the characteristics of truck mounted concrete pump strain signal,a new method of removing singular value based on the variation rate is proposed.Singular values are determined by whether variation rate of strain signal is out of removing range decided by variation of strain signal.Singular values are revised according to the extent that singular values deviate from the normal range.The variation rate method is presented in detail.The simulation result using Matlab shows that the variation rate method is more effective than 3σ-rule in removing isolated singular values of strain signal.What is more,the method also works well in the case that there are not too many consecutive singular values in the strain data.