Disturbances and model uncertainties often have large impact on model based fault detection and isolation (FDI) processes and result in false alarm or reduced fault detection rate. In rotor systems exited by unbalances, the predominant disturbances (e.g. unbalance forces) and model uncertainties caused by gyroscopic effect appear in a sinusoidal form with rotor rotary frequency. If the influenc...

Rotor crack detection method by using multi-vibration signals gathered at the basements is presented in this paper. The finite element software ANSYS is applied for analyzing the vibration response characteristics of the basement to determine sensor configuration. Feature fusion for time-domain statistics of multiple sensors is performed by using the support vector machine to diagnose the depth...

-This paper develops a novel spectrum enhancement method to simplify the spectrum representation. It uses a forward synchronous transform to convert three phase current signals into the two current signals in the synchronous reference frame. The spectrum obtained by applying Fast Fourier Transform (FFT) to one of the transformed current signals is then maximized by varying the initial phase in ...

The demountable disk-drum aero-engine rotor is an important piece of equipment that greatly impacts the safe operation of aircraft. However, assembly looseness or crack fault has led to several unscheduled breakdowns and serious accidents. Thus, condition monitoring and fault diagnosis technique are required for identifying abnormal conditions. Customized ensemble multiwavelet method for aero-e...

According to modern grid regulations, doubly fed induction generator (DFIG) needs to operate without losing synchronism during grid faults. But, severe fault leads to rise in stator and rotor current to a higher value and generator will get damaged. Large oscillations in stator real and reactive power are produced and consequently large torque oscillations get developed. To overcome the above a...

Observers are widely used to generate residuals for fault diagnosis processes. However the generated residuals are not only influenced by faults but also by disturbances and model uncertainties. In order to avoid false alarm and achieve a high fault detection rate disturbances and model uncertainties have to be considered in the fault detection and isolation (FDI) processes. In rotor systems th...

In this paper, in view of the advantages of widely used Proportional-Integral-Derivative (PID) controller and gain scheduling control strategy in aerospace and industrial applications, a control strategy by using gain scheduling based PID controller is proposed for fault tolerant control (FTC) of a quad-rotor Unmanned Aerial Vehicle (UAV). The nonlinear dynamic equations of motion of the quad-r...

In this article, a new fault detection technique is proposed for squirrel cage induction motor SCIM based on detection of rotor bar failure. This type of fault detection is commonly carried out, while motor continues to work at a steady-state regime. Recently, several methods have been presented for rotor bar failure detection based on evaluation of the start-up transient current. The proposed ...

This paper inspects the misaligned motors by using diagnostic medium such as current, flux and instantaneous power signal. Misalignments in machines can cause decrease in efficiency and in the long-run it may cause disastrous failure because of unnecessary vibration, stress on motor & bearings and short-circuiting in stator and rotor windings. The measurements have been performed at full-load t...

This study examined and presents an effective method for detection of failure of conductor bars in the winding of rotor of induction motor in low load conditions using neural networks of radial-base functions. The proposed method used Hilbert method to obtain the stator current signal push. The frequency and signal amplitude of the push stator were used as the input of the neural network and th...