On the Use of the Instantaneous Angular Speed Measurement in Non Stationary Mechanism Monitoring

2011 ◽  
Author(s):  
Hugo Andre´ ◽  
Didier Re´mond ◽  
Adeline Bourdon
Keyword(s):  
Energy Production ◽  
Power Transmission ◽  
Angular Speed ◽  
Vibration Monitoring ◽  
Stationary Condition ◽  
Speed Measurement ◽  
Monitoring Tools ◽  
Instantaneous Angular Speed ◽  
Stationary Conditions ◽  
Localized Faults

Power transmission faults are one important cause of machine downtime many production activities are working to prevail. Vibration monitoring tools have achieved this role on the assumption that the stationary condition hypothesis is maintained. Several industries, including wind energy production, are however demanding to observe mechanical or electrical rotating components behaviour at variable speeds. Instantaneous angular speed measurement has been recently proven able to detect localized faults in bearings using only an encoder close from the source of the defect. This paper presents the results obtained from a large span experiment on a 2MW wind turbine. The uniqueness of the sensor used to monitor the whole line shafting along with the continuous non stationary conditions are so many difficulties cumulated on this attempt. Two basic signal processing tools are theoretically defined and experimentally applied in an original way on the Instantaneous Angular Speed measurement to efficiently tackle these practical issues.

A practical signal processing approach for fault detection of axial piston pumps using instantaneous angular speed

2020 ◽  
Vol 234 (19) ◽  
pp. 3935-3947
Author(s):  
Jia-Min Liu ◽  
Li-Chen Gu ◽  
Bao-Long Geng
Keyword(s):  
Fault Detection ◽  
Fault Location ◽  
Signal To Noise Ratio ◽  
Linear Interpolation ◽  
Angular Speed ◽  
Vibration Monitoring ◽  
Transfer Path ◽  
Instantaneous Angular Speed ◽  
Speed Fluctuation ◽  
Axial Piston

The axial piston pump is a core component for power output conversion in the hydraulic system. Monitoring pump status and diagnosing faults in an optimal way are of profound significance for ensuring system reliability. Currently, considerable studies concentrate primarily on the development of vibration-monitoring technologies. However, due to strong fluid shock and noise, vibration analysis has low signal-to-noise ratio and difficulty in fault location. Therefore, an approach of instantaneous angular speed-based fault detection is introduced in this paper since it has the advantages of short transfer path and non-intrusive measurement. Instantaneous angular speed (IAS) is obtained by cross-period linear interpolation (CLI) algorithm for the voltage square wave induced by a magneto-electric tachometer transducer. Compared with the elapsed time method, CLI has the capacity to precisely capture the speed fluctuation. Weighted angle synchronous averaging (WASA) is then utilized to realize the extraction of abnormal wave components in IAS as a vital signal preprocessing method. Instantaneous angular speed fluctuation (IASF) characteristics of the angular domain are analyzed to study the fault diagnosis under varying working conditions. Moreover, it is proven that after processing, the fault features are extracted in the order spectrum where the deterministic shaft order and its harmonics corresponding to wear characteristics are displayed clearly. Experimental results indicate that IAS has demonstrated more effective and sensitive than vibration signals, thus providing a promising tool for the health monitoring of a pump.

Some approaches on instantaneous angular speed measurement using a two-phase n poles AC generator as sensor

Measurement ◽  
2020 ◽  
Vol 157 ◽  
pp. 107636 ◽  
Author(s):  
Mihaita Horodinca ◽  
Ionut Ciurdea ◽  
Dragos-Florin Chitariu ◽  
Adriana Munteanu ◽  
Mihai Boca
Keyword(s):  
Angular Speed ◽  
Two Phase ◽  
Speed Measurement ◽  
Instantaneous Angular Speed

scholarly journals Fault detection based on instantaneous angular speed measurement and variational mode decomposition

2018 ◽  
Vol 211 ◽  
pp. 18006 ◽  
Author(s):  
Sanjin Braut ◽  
Roberto Žigulić ◽  
Ante Skoblar ◽  
Goranka Štimac Rončević
Keyword(s):  
Fault Detection ◽  
Laboratory Test ◽  
Angular Speed ◽  
Operating Conditions ◽  
Variational Mode Decomposition ◽  
Test Rig ◽  
Displacement Sensors ◽  
Speed Measurement ◽  
Mode Decomposition ◽  
Instantaneous Angular Speed

Rotating machinery encounter throughout their lifetime various problems. Among them, a rotor-stator rubbing problem is one of the most common. This paper proposes a procedure, which applies the instantaneous angular speed (IAS) measurement as a starting step for rotor-stator partial rub detection. There are various approaches regarding counting techniques and processing of signal. In this paper, an application of analog signals from toothed wheel encoder or zebra tape encoder is considered at low to moderate sampling rates. As the rubbing process is nonlinear, this paper is proposing a variational mode decomposition (VMD) as the second step of the detection procedure. The VMD is relatively new method with promising results especially interesting for machinery fault detection. Detection tool is tested on laboratory test rig at two different rotor operating conditions i.e. without rotor-stator rubbing and with light partial rotor-stator rub. Measurements were performed with non-contact eddy current displacement sensors pointed to toothed wheel encoder. Results are presented in the shape of rotor orbits, IAS signals, FFT spectra of IAS signals and VMD spectrograms. Developed fault detection procedure based on IAS measurement and VMD decomposition was successfully tested on laboratory test rig for no rubbing and light rotor to stator partial rub condition.

Sign in / Sign up

Export Citation Format

Share Document