Rub-impact is a common nonlinear fault of the rotor system, occurring in rotating machines with radial clearance between the rotor and the stator, which may lead to serious consequences. Since the vibration response of rotor rub-impact is shown as multicomponent with time-varying characteristics of undulatory instantaneous frequency, it is desired to exploit advanced signal processing methods for rub-related feature excavation and failure diagnosis under complex noise interferences, which is of crucial significance to ensure the stable and efficient operation of the whole unit. This paper concerns the processing of acceleration signals and proposes a novel intrawave frequency modulation detection approach for structural rotor rubbing diagnosis based upon targeted component extraction and stochastic resonance enhancement. First, the acquired vibratory acceleration signal is converted into displacement signal via a two-stage integration strategy. Next, to extract the rotating frequency component of high information clarity for further time–frequency analysis from the multicomponent signal, an especially designed improved variational mode decomposition method based on the modified target frequency index is put forward, and the instantaneous frequency of the objective component is estimated. Then, the optimum stochastic resonance is leveraged for intrawave frequency modulation enhancement. Finally, the rotor rub-related symptom can be distinctly revealed and the diagnostic procedure can be performed. The effectiveness and superiority of the proposed rotor rub-impact diagnosis approach are demonstrated through both simulations and experiments, indicating that it is suitable to be implemented in practical applications, with high noise-resistance ability, and can efficiently extract the potential characteristics of rotor rub-impact malfunction from multicomponent signals.

中文翻译：

---

基于目标成分提取和随机共振增强的复杂噪声干扰下结构转子摩擦冲击诊断

碰摩是转子系统常见的非线性故障，发生在转子和定子之间存在径向间隙的旋转电机中，可能导致严重后果。由于转子碰摩冲击的振动响应表现为具有波动瞬时频率时变特性的多分量，因此需要利用先进的信号处理方法进行复杂噪声干扰下的碰摩相关特征挖掘和故障诊断，这至关重要对保证整个机组稳定高效运行具有重要意义。本文关注加速度信号的处理，提出了一种基于目标分量提取和随机共振增强的新型波内调频检测方法，用于结构转子摩擦诊断。首先，通过两级积分策略将获取的振动加速度信号转换为位移信号。接下来，为了从多分量信号中提取信息清晰度高的旋转频率分量以进行进一步的时频分析，提出了一种基于修正目标频率指标的改进变分模态分解方法，并得到了目标分量的瞬时频率。是估计的。然后，利用最佳随机谐振来增强波内频率调制。最后，可以清楚地显示转子摩擦相关的症状并可以执行诊断程序。通过仿真和实验验证了所提出的转子摩擦冲击诊断方法的有效性和优越性，表明该方法适合在实际应用中实现，具有较高的抗噪声能力，并且可以有效地提取转子摩擦的潜在特征。 -多分量信号影响故障。