Abstract The present work brings out a novel model based analysis and identification of the additive and multiplicative fault parameters in an active magnetic bearing (AMB) controlled rotor system. In mathematical modeling, the unbalance is considered as an additive fault, whereas the effect of shaft residual bow on crack are considered as multiplicative faults. In equations of motion (EOMs), the multiplicative fault parameters appear in a product form, which is much more challenging to handle as well of the practical importance for its analysis and identification. EOMs have been developed considering the influences of the external as well as internal (rotating) damping, and the gyroscopic effect due to axially offset disc on the rotor-AMB system. The shaft has a transverse fatigue crack (breathing model) and an initial shaft bow. The proposed rotor-AMB model uses a PID (proportional-integral-derivative) controller to regulate the supply currents to the AMB to actively control the vibration of the system due to inherent faults. In the response analysis, the effects of rotor faults on the rotor displacements and AMB control currents are shown in full spectrum. Furthermore, an identification methodology has been developed from complex frequency domain EOMs to facilitate the estimation of the additive and multiplicative fault parameters in a cracked bowed rotor system. To comply with the practical aspects, different measurement noises and modeling errors have been added to test the robustness of the proposed algorithm.

中文翻译：

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带辅助主动磁轴承的裂纹弯曲不平衡转子系统加法和乘法故障参数分析与辨识

摘要 目前的工作提出了一种新的基于模型的分析和识别有源磁轴承 (AMB) 控制的转子系统中的加法和乘法故障参数。在数学建模中，不平衡被认为是加性故障，而轴残余弓对裂纹的影响被认为是乘性故障。在运动方程 (EOM) 中，乘积故障参数以乘积形式出现，处理起来更具挑战性，并且对其分析和识别具有实际重要性。EOM 的开发考虑了外部和内部（旋转）阻尼的影响，以及由于转子-AMB 系统上的轴向偏移盘引起的陀螺效应。轴有横向疲劳裂纹（呼吸模型）和初始轴弓。所提出的转子-AMB 模型使用 PID（比例-积分-微分）控制器来调节 AMB 的电源电流，以主动控制由于固有故障而导致的系统振动。在响应分析中，转子故障对转子位移和 AMB 控制电流的影响以全谱显示。此外，已经从复杂的频域 EOM 开发了一种识别方法，以促进裂纹弓形转子系统中加性和乘性故障参数的估计。为了符合实际情况，增加了不同的测量噪声和建模误差来测试所提出算法的鲁棒性。