Li Yifan, Yang Yaocheng, Chen Yuejian, Chen Zaigang
School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China.
Department of Mechanical Engineering, University of Alberta, Edmonton T6G 2G8, Canada.
ISA Trans. 2022 Jan;119:172-183. doi: 10.1016/j.isatra.2021.02.031. Epub 2021 Feb 24.
Ridge extraction is an effective tacholess order tracking technique for the fault detection of bearings under time-varying speed conditions. Cost function ridge detection (CFRD) is the most widely used ridge detection method. However, improper bandwidth selection and unreasonable cost function construction significantly restrict the performance of the CFRD. To address the two shortcomings of the CFRD, an improved CFRD (ICFRD) method is firstly proposed in this paper. The ICFRD integrates an adaptive search bandwidth determination technique that varies the search region with signal signatures, as well as a novel cost function that comprehensively considers the trade-off between ridge amplitude and smoothness. An iterative characteristic ridge extraction (ICRE) strategy is then presented based on the ICFRD to extract multiple characteristic ridges in a time-frequency plane automatically. The average frequency ratios between the extracted characteristic ridges are calculated to estimate bearing fault characteristic orders and therefore detect bearing faults. The performance of the proposed method was tested using simulated signals and experimental vibration signals collected from a machinery test rig. Results show that the ICRE outperforms the conventional CFRD in terms of detecting bearing faults under variable speed conditions. The average relative errors between the extracted instantaneous frequencies and the theoretical ones of the ICRE are 0.85%, 2.11% and 0.63% for inner race fault, outer race fault, and healthy bearing vibration signal, respectively. These values are much smaller than the results of using the CFRD.
脊线提取是一种有效的无转速阶次跟踪技术，用于在变速条件下对轴承进行故障检测。代价函数脊线检测（CFRD）是应用最广泛的脊线检测方法。然而，带宽选择不当和代价函数构建不合理显著限制了CFRD的性能。为了解决CFRD的这两个缺点，本文首先提出了一种改进的CFRD（ICFRD）方法。ICFRD集成了一种自适应搜索带宽确定技术，该技术根据信号特征改变搜索区域，以及一种综合考虑脊线幅度和平滑度之间权衡的新型代价函数。然后基于ICFRD提出了一种迭代特征脊线提取（ICRE）策略，以在时频平面上自动提取多个特征脊线。计算提取的特征脊线之间的平均频率比，以估计轴承故障特征阶次，从而检测轴承故障。使用模拟信号和从机械试验台收集的实验振动信号对所提方法的性能进行了测试。结果表明，在变速条件下检测轴承故障方面，ICRE优于传统的CFRD。对于内圈故障、外圈故障和健康轴承振动信号，ICRE提取的瞬时频率与理论值之间的平均相对误差分别为0.85%、2.11%和0.63%。这些值远小于使用CFRD的结果。
