1. State key Laboratory of Advanced Design and Manufacture for Vehicle Body, Hunan University, Changsha 410082, China;
2. School of Mechanical Engineering, Anhui University of Technology, Ma′anshan 243002, China
摘要针对局部特征尺度分解(Local Characteristic-scale Decomposition,LCD)方法中两极值点连线在极值点处一阶微分不连续，引起分解精度降低问题，提出新非平稳信号分析方法-基于分段多项式的局部特征尺度分解(Piecewise Polynomial based Local Characteristic-scale Decomposition, PPLCD)。用分段多项式取代LCD中直线连接，且均值曲线插值点由相邻3个同类极值点构成的多项式计算产生。通过仿真信号将PPLCD与LCD对比，结果表明，PPLCD在提高分量正交性、精确性等具有一定优越性；由转子碰摩故障诊断表明该方法的有效性。
Abstract：A novel nonstationary signal method PPLCD was proposed for improving the problem of LCD, of which，the first derivative of extremum points in the connecting line of two extreme value points was discontinuous, thereby the decomposition precision was lowered. Piecewise polynomial was used in PPLCD to replace line connection in LCD, and the mean curve interpolation points were computed by the polynomial which was generated by three adjacent similar extremum points. The paper firstly studied the theory of PPLCD，then simulation experiments were used to compare PPLCD with LCD. The results indicate that PPLCD is more efficient in improving the orthogonality and veracity in components than LCD. Finally, the proposed method was applied to diagnose the rotor with rub-impact fault successfully which indicated the effectiveness of PPLCD.
吴占涛1，程军圣1，曾 鸣1，郑近德2. 基于分段多项式的局部特征尺度分解方法及应用[J]. 振动与冲击, 2016, 35(4): 230-234.
WU Zhan-tao1，CHENG Jun-sheng1，ZENG Ming1，ZHENG Jin-de2. The method of piecewise polynomial based local characteristic-scale decomposition and its application. JOURNAL OF VIBRATION AND SHOCK, 2016, 35(4): 230-234.
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