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A Novel De-noising Method Based on Discrete Cosine Transform and Its Application in the Fault Feature Extraction of hydraulic pump

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Journal of Shanghai Jiaotong university(Science) 2016年第3期21卷 297-306页

作者：王余奎黄之杰赵徐成朱毅魏东涛 Air Force Logistics College of PLA Xuzhou 221000JiangsuChina Ordnance Engineering College of PLA Shijiazhuang 050003China

Aiming at the existing problems of discrete cosine transform(DCT) de-noising method, we introduce the idea of wavelet neighboring coefficients(WNC) de-noising method, and propose the cosine neighboring coefficients(CNC) de-noising method. Based on DCT, a novel method for the fault feature extraction of hydraulic pump is analyzed. The vibration signal of pump is de-noised with CNC de-noising method, and the fault feature is extracted by performing Hilbert-Huang transform(HHT) to the output signal. The analysis results of the simulation signal and the actual one demonstrate that the proposed CNC de-noising method and the fault feature extraction method have more superior ability than the traditional ones.

关键词： discrete cosine transform(DCT) de-noising method cosine neighboring coefficients(CNC) de-noising method hydraulic pump fault feature extraction

Performance optimization of grooved slippers for aero hydraulic pumps

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Chinese Journal of Aeronautics 2016年第3期29卷 814-823页

作者： Chen Juan Ma Jiming Li Jia Fu Yongling Department of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Sino-French Engineer School Beihang UniversityBeijing 100191China AVIC Xi'an Flight Automatic Control Research Institute.Xi'an 710065 China

A computational fluid dynamics （CFD） simulation method based on 3-D Navier Stokes equation and Arbitrary Lagrangian Eulerian （ALE） method is presented to analyze the grooved slip- per performance of piston pump. The moving domain of grooved slipper is transformed into a fixed reference domain by the ALE method, which makes it convenient to take the effects of rotate speed, body force, temperature, and oil viscosity into account. A geometric model to express the complex structure, which covers the orifice of piston and slipper, vented groove and the oil film, is constructed. Corresponding to different oil film thicknesses calculated in light of hydrostatic equilibrium theory and boundary conditions, a set of simulations is conducted in COMSOL to analyze the pump characteristics and effects of geometry （groove width and radius, orifice size） on these characteristics. Furthermore, the mechanics and hydraulics analyses are employed to validate the CFD model, and there is an excellent agreement between simulation and analytical results. The simulation results show that the sealing land radius, orifice size and groove width all dramatically affect the slipper behavior, and an optimum tradeoff among these factors is conducive to optimizing the pump design.

关键词： Arbitrary LagrangianEulerian (ALE) Computational fluid dynam-ics (CFD) Grooved slipper hydraulic pump Navier-Stokes equation Performance analysis

Life prediction and test period optimization research based on small sample reliability test of hydraulic pumps

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High Technology Letters 2017年第1期23卷 63-70页

作者：郭锐 Ning Chao Zhao Jingyi Wang Ping Shi Yu Zhou Jinsheng Luo Jing Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityKey Laboratory of Advanced Forging&Stamping Technology and Science(Yanshan University)Qinhuangdao 066004P.R.China Huachuang Tianyuan Industrial Developing Co. LtdLangfang 065000P.R.China College of Art and Design Yanshan UniversityQinhuangdao 066004P.R.China Beijing Research Institute of Automation for Machinery Industry Beijing 100120P.R.China

hydraulic pumps belong to reliable long-life hydraulic components. The reliability evaluation includes characters such as long test period,high cost,and high power loss and so on. Based on the principle of energy-saving and power recovery,a small sample hydraulic pump reliability test rig is built,and the service life of hydraulic pump is predicted,and then the sampling period of reliability test is optimized. On the basis of considering the performance degradation mechanism of hydraulic pump,the feature information of degradation distribution of hydraulic pump volumetric efficiency during the test is collected,so an optimal degradation path model of feature information is selected from the aspect of fitting accuracy,and pseudo life data are obtained. Then a small sample reliability test of period constrained optimization search strategy for hydraulic pump is constructed to solve the optimization problem of the test sampling period and tightening end threshold,and it is verified that the accuracy of the minimum sampling period by the non-parametric hypothes is tested. Simulation result shows it could possess instructional significance and referenced value for hydraulic pump reliability life evaluation and the test's research and design.

关键词： hydraulic pump small sample test volumetric efficiency degradation path model life span period optimal

Research Status, Critical Technologies, and Development Trends of hydraulic Pressure Pulsation Attenuator

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Chinese Journal of Mechanical Engineering 2021年第1期34卷 114-130页

作者： Yan Wang Tongsheng Shen Chunsen Tan Jian Fu Shengrong Guo School of Transportation Science and Engineering Beihang UniversityBeijing 100083China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100083China Nanjing Engineer Institute of Air-craft Systerm Jincheng AVICNanjing 211100China

hydraulic pumps are a positive displacement pump whose working principle causes inherent output flow *** pulsation produces pressure pulsation when encountering liquid *** pulsation spreads in the pipeline and causes vibration,noise,damage,and even pipeline rupture and major safety *** the development of airborne hydraulic systems with high pressure,power,and flow rate,the hazards of vibration and noise caused by pressure pulsation are also amplified,severely restricting the application and development of hydraulic *** this review paper,the mechanism,harm,and suppression method of pressure pulsation in hydraulic systems are ***,the classification and characteristics of pulsation attenuators according to different working principles are ***,the critical technology of simulation design,matching method with airborne piston pumps,and preliminary design method of pulsation attenuators are ***,the development trend of pulsation attenuators is *** paper provides a reference for the research and application of pressure pulsation attenuators.

关键词： hydraulic pump Pressure pulsation Pulsation attenuator

Control System Development of the One-axis hydraulic Road Simulator Using QFT

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Control System Development of the One-axis Hydraulic Road Si...