Data-driven fault diagnosis of FW-UAVs with consideration of multiple operation conditions

The diesel engine has been a significant component of large-scale mechanical systems for the intelligent manufacturing industry. Because of its complex structure and poor working environment, it has trouble effectively acquiring the representative fault features. Further, fault diagnosis of the diesel engine faces great challenges. This paper presents a new fault diagnosis method for the detection of diesel engine faults under multiple operation conditions instead of conventional methods confined to a single condition. First, an adaptive correlation threshold process is designed as a preprocessing unit to enhance data quality by weakening non-impact region characteristics. Next, a feature extraction method for sound signals based on the Mel frequency cepstrum (MFC) is improved and introduced into the machinery fault diagnosis. Then, the combination of the improved feature and vibrational mode decomposition (VMD) is proposed to incorporate VMD into an effective adaptive decomposition of non-stationary signals to combine it with an excellent feature representation of the vibration signal. Finally, the vector quantization algorithm is adopted to reduce the feature dimensions and generate codebook model bases, which trains the K-Nearest Neighbor classifiers. Five comparative methods were carried out, and the experimental results show that the proposed method offers a good effect of the common valve clearance fault of diesel engines under different conditions.

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Comparative study on the use of acoustic emission and vibration analyses for the bearing fault diagnosis of high-speed trains

Structural Health Monitoring ◽

10.1177/14759217211036025 ◽

2021 ◽

pp. 147592172110360

Author(s):

Dongming Hou ◽

Hongyuan Qi ◽

Honglin Luo ◽

Cuiping Wang ◽

Jiangtian Yang

Keyword(s):

Acoustic Emission ◽

Fault Diagnosis ◽

High Speed ◽

High Speed Train ◽

Signal Attenuation ◽

Transmission Path ◽

Bearing Fault Diagnosis ◽

Operation Conditions ◽

Fault Features ◽

High Speed Trains

A wheel set bearing is an important supporting component of a high-speed train. Its quality and performance directly determine the overall safety of the train. Therefore, monitoring a wheel set bearing’s conditions for an early fault diagnosis is vital to ensure the safe operation of high-speed trains. However, the collected signals are often contaminated by environmental noise, transmission path, and signal attenuation because of the complexity of high-speed train systems and poor operation conditions, making it difficult to extract the early fault features of the wheel set bearing accurately. Vibration monitoring is most widely used for bearing fault diagnosis, with the acoustic emission (AE) technology emerging as a powerful tool. This article reports a comparison between vibration and AE technology in terms of their applicability for diagnosing naturally degraded wheel set bearings. In addition, a novel fault diagnosis method based on the optimized maximum second-order cyclostationarity blind deconvolution (CYCBD) and chirp Z-transform (CZT) is proposed to diagnose early composite fault defects in a wheel set bearing. The optimization CYCBD is adopted to enhance the fault-induced impact response and eliminate the interference of environmental noise, transmission path, and signal attenuation. CZT is used to improve the frequency resolution and match the fault features accurately under a limited data length condition. Moreover, the efficiency of the proposed method is verified by the simulated bearing signal and the real datasets. The results show that the proposed method is effective in the detection of wheel set bearing faults compared with the minimum entropy deconvolution (MED) and maximum correlated kurtosis deconvolution (MCKD) methods. This research is also the first to compare the effectiveness of applying AE and vibration technologies to diagnose a naturally degraded high-speed train bearing, particularly close to actual line operation conditions.

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A data-driven approach for fault diagnosis in HVAC chiller systems

2015 IEEE Conference on Control Applications (CCA) ◽

10.1109/cca.2015.7320737 ◽

2015 ◽

Cited By ~ 4

Author(s):

Alessandro Beghi ◽

Riccardo Brignoli ◽

Luca Cecchinato ◽

Gabriele Menegazzo ◽

Mirco Rampazzo

Keyword(s):

Fault Diagnosis ◽

Data Driven ◽

Data Driven Approach

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Operation Optimization Approaches of Thermal Power Units with Big Data-Driven Hybrid Modeling

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.631-632.362 ◽

2014 ◽

Vol 631-632 ◽

pp. 362-366

Author(s):

Ning Ling Wang ◽

Yong Zhang ◽

Long Fei Zhu ◽

Zhi Ping Yang

Keyword(s):

Energy Consumption ◽

Thermal Power ◽

Hybrid Modeling ◽

Data Driven ◽

Fuzzy Rough Set ◽

Operation Optimization ◽

Operation Conditions ◽

Energy Consumption Model ◽

Practical Guidelines ◽

Data Driven Modeling

An accurate and reliable energy-consumption model is the key to operation optimization and energy-saving diagnosis of thermal power units especially under different operation conditions and boundaries. Conventional mathematical and data-driven modeling methods were overviewed and compared in this paper. A hybrid modeling based on thermodynamic theory and fuzzy rough set (FRS) method was proposed to process the great volume of operation data and describe the energy-consumption behavior of thermal power units. On this basis, the operation optimization was performed with intelligent computation methods to derive the realizable benchmark state with the whole set of operation parameters. The resultant optimum operation state reflects the exterior factors and system behavior, taking practical guidelines for the modeling and optimization of large thermal power units.

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