A Study on Simulation of Vibration Source Excited by Engine

2014 ◽  
Vol 543-547 ◽  
pp. 215-218
Author(s):  
Wei Yang ◽  
Wen Ku Shi ◽  
Chun Xue Chen ◽  
Zhi Yong Chen
Keyword(s):  
Power Unit ◽  
Working Conditions ◽  
Dynamic Method ◽  
Working Condition ◽  
Engine Block ◽  
Vibration Source ◽  
Vibration Acceleration ◽  
Unit Module ◽  
Engine System ◽  
Method Model

Vibration exciting theory of working engine was analyzed based on dynamic method. Model of engine system and mounts was established and simulated in multiple working conditions by Power Unit module of dynamics software excite. Vibration acceleration of points on engine block adjacent to each mount was extracted to characterize and evaluate the vibration excited by engine in different working condition.

BP-AdaBoost Algorithm Based on Variational Mode Decomposition Optimized by Envelope Entropy for Diagnosing the Working Conditions of a Slideway Seedling-Picking Mechanism

2021 ◽  
Vol 37 (4) ◽  
pp. 665-675
Author(s):  
Zhitao He ◽  
Haiyang Zhang ◽  
Jun Wang ◽  
Xin Jin ◽  
Song Gao ◽  
...  
Keyword(s):  
Empirical Mode Decomposition ◽  
Working Conditions ◽  
Working Condition ◽  
Recognition Accuracy ◽  
Variational Mode Decomposition ◽  
Adaboost Algorithm ◽  
Layer Number ◽  
Entropy Minimization ◽  
Mode Decomposition ◽  
Penalty Factor

Highlights A method of monitoring the working conditions of a slideway seedling-picking mechanism based on variational mode decomposition (VMD), envelope entropy, and energy entropy is proposed. Based on the criterion of envelope entropy minimization, the combination of the decomposition layer number and penalty factor in VMD is optimized to yield a satisfactory decomposition effect of the analyzed vibration signal. The BP-AdaBoost algorithm is used to improve the working condition classification performance for the slideway seedling-picking mechanism. The working-condition identification effect with the proposed method are compared with those through EMD-based, LMD-based, and EEMD-based methods. Abstract . The slideway seedling-picking mechanism is a type of rotating machinery. This study proposes a novel method of identifying the working conditions of slideway seedling-picking mechanisms for early fault diagnosis by utilizing a back-propagation adaptive boosting (BP-AdaBoost) algorithm based on variational mode decomposition (VMD) optimized by the envelope entropy. The experimental results demonstrate that the proposed method can effectively verify the four working conditions (normal state, slideway failure, cam failure, and spring failure). The overall recognition accuracy reaches 90.0% under the optimal combination of the decomposition layer number K and penalty factor a in VMD determined through the envelope entropy minimization criterion. Classification comparisons with empirical mode decomposition (EMD), local mean decomposition (LMD) and ensemble empirical mode decomposition (EEMD) integrated into the BP-AdaBoost algorithm indicate that the overall recognition accuracy of the proposed method is 18.1%, 16.9%, and 15.6% higher than the accuracies of the three conventional methods, respectively. Compared with the K-means, support vector machine (SVM) algorithms, BP-AdaBoost algorithm demonstrates a more dependable capability for identifying the working conditions. This study provides a useful reference for monitoring the working conditions of slideway seedling-picking mechanisms. Keywords: BP-AdaBoost algorithm, Energy entropy, Envelope entropy, Slideway seedling-picking mechanism, Variational mode decomposition, Working conditions.

Winding-Autofrettage Study on Reinforced Thermoplastics Vessel Based on ANSYS ACP

2018 ◽  
Author(s):  
Jinhao Huang ◽  
Chenghong Duan ◽  
Liang Wu ◽  
Xiangpeng Luo
Keyword(s):  
Stress Distribution ◽  
Internal Pressure ◽  
Working Conditions ◽  
High Density Polyethylene ◽  
Working Condition ◽  
Filament Winding ◽  
Working Pressure ◽  
Cooling Method ◽  
Plastic Stage ◽  
Reinforced Thermoplastics

The process, by applying an internal pressure higher than the working pressure in advance after completion of the winding to cause the liner entering the plastic stage and producing the corresponding permanent plastic deformation for the purpose of improving the carrying capacity of the vessel, is called internal pressure autofrettage. In this paper, for the high-density polyethylene liner filament winding vessels which are winded by the equivalent cooling method, the ANSYS ACP module is used to analyze the stress distribution under autofrettage condition and working condition. The influence of autofrettage pressure and cooling temperature on the stress distribution under the working conditions of the vessel is addressed. This study could provide a reference for the optimization of winding process.

scholarly journals Deep Transfer Learning-Based Fault Diagnosis for Gearbox under Complex Working Conditions

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zitong Wan ◽  
Rui Yang ◽  
Mengjie Huang
Keyword(s):  
Fault Diagnosis ◽  
Transfer Learning ◽  
Working Conditions ◽  
Evaluation Method ◽  
Working Condition ◽  
Negative Effects ◽  
Gear Fault ◽  
Diagnosis Method ◽  
Fault Feature Extraction ◽  
Better Than

In the large amount of available data, information insensitive to faults in historical data interferes in gear fault feature extraction. Furthermore, as most of the fault diagnosis models are learned from offline data collected under single/fixed working condition only, this may cause unsatisfactory performance for complex working conditions (including multiple and unknown working conditions) if not properly dealt with. This paper proposes a transfer learning-based fault diagnosis method of gear faults to reduce the negative effects of the abovementioned problems. In the proposed method, a cohesion evaluation method is applied to select sensitive features to the task with a transfer learning-based sparse autoencoder to transfer the knowledge learnt under single working condition to complex working conditions. The experimental results on wind turbine drivetrain diagnostics simulator show that the proposed method is effective in complex working conditions and the achieved results are better than those of traditional algorithms.

scholarly journals Design and Analysis of Refined Inspection of Field Conditions of Oilfield Pumping Wells Based on Rotorcraft UAV Technology

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1504 ◽  
Author(s):  
Yu Zhou ◽  
Chunxue Wu ◽  
Qunhui Wu ◽  
Zelda Makati Eli ◽  
Naixue Xiong ◽  
...  
Keyword(s):  
Real Time ◽  
Working Conditions ◽  
Working Condition ◽  
Oil Well ◽  
Monitoring Method ◽  
The Real ◽  
Multi Target Tracking ◽  
Key Factor ◽  
Real Time Detection ◽  
Rotorcraft Uav

The traditional oil well monitoring method relies on manual acquisition and various high-precision sensors. Using the indicator diagram to judge the working condition of the well is not only difficult to establish but also consumes huge manpower and financial resources. This paper proposes the use of computer vision in the detection of working conditions in oil extraction. Combined with the advantages of an unmanned aerial vehicle (UAV), UAV aerial photography images are used to realize real-time detection of on-site working conditions by real-time tracking of the working status of the head working and other related parts of the pumping unit. Considering the real-time performance of working condition detection, this paper proposes a framework that combines You only look once version 3 (YOLOv3) and a sort algorithm to complete multi-target tracking in the form of tracking by detection. The quality of the target detection in the framework is the key factor affecting the tracking effect. The experimental results show that a good detector makes the tracking speed achieve the real-time effect and provides help for the real-time detection of the working condition, which has a strong practical application.

Implementation of dynamic working condition seawater desalination system optimization and simulation model

2016 ◽  
Vol 16 (5) ◽  
pp. 1417-1431
Author(s):  
Zhihan Zhao ◽  
Yuan Zheng ◽  
Zaiqiang Wu
Keyword(s):  
Working Conditions ◽  
Working Condition ◽  
System Optimization ◽  
Important Research ◽  
Seawater Desalination ◽  
Development Platform ◽  
Important Research Topic ◽  
Refinement Process ◽  
Optimization And Simulation ◽  
Working Device

Freshwater is an increasingly important research topic in the 21st century, similar to the importance of coal and oil in the 19th and 20th centuries, respectively. To expand expertise on desalination systems, this study aims to design a set of seawater desalination systems with dynamic working conditions based on the visualized development platform LABVIEW. The optimization searched for the optimal working conditions and formed the seawater desalination refinement process control technology and solution. A scaled dynamic load working device safety and protection solution was obtained, and an ideal scenario compared with the real operation environment was reproduced to assist people in operating and running the system.

The Monitoring of Machine Tool Working State Based on Load Current Signal

2010 ◽  
Vol 37-38 ◽  
pp. 1512-1515 ◽  
Author(s):  
Guang Lin Yu ◽  
Guo Fu Li
Keyword(s):  
Working Conditions ◽  
Machine Tools ◽  
Working Condition ◽  
Wavelet Packet ◽  
Analytical Signal ◽  
Wavelet Packet Decomposition ◽  
Machine Condition ◽  
Current Signal ◽  
Motor Current ◽  
Machine Condition Monitoring

According to the characteristic of machine tools such as complex driving chain and enclosed housing, this paper selects current signal which is easy to sample as the analytical signal. As the machines tools use different driving chain in different work state, this will affect motor current of machine tools; that is, the characteristics under different working conditions will be included in the current signal. This paper chose wavelet packet decomposition to analyze the current signal, then extracted wavelet packet coefficients of different frequency bands, by the change of wavelet packet coefficient to determine the machine's working condition. From the analysis of lathe current signal sampled in the experiment, it indicates the validity of wavelet packet coefficients as a feature quantity of the machine condition monitoring.

Study on Slip Phenomenon of Pumps As Turbines in Different Working Conditions

2017 ◽  
Author(s):  
Wang Xiaohui ◽  
Yang Junhu ◽  
Xia Zhengting
Keyword(s):  
Working Conditions ◽  
Working Condition ◽  
Suction Side ◽  
Hydraulic Loss ◽  
Hydraulic Efficiency ◽  
High Discharge ◽  
Flow Parameters ◽  
Slip Factor ◽  
Point Condition ◽  
Slip Phenomenon

Slip phenomenon is known to strongly influence the performance of pump as turbine (PAT). It is of interest to investigate the influence of flow parameters on the slip factor and obtain the effective value of slip factor over the whole range of their working conditions. In the present work, the slip phenomenon of PAT at different working condition was studied, slip factor was calculated in every point of the flow. Furthermore, the relative eddy within the impeller passage was evaluated and the hydraulic performance of PAT was analyzed. The result shows that the slip factor decreases with the increasing flow rate, slip phenomenon induces additional hydraulic loss in impeller passage, it weakened in over-load region, as a consequence, hydraulic efficiency is relatively high. On the contrary, the slip phenomenon strengthened in part-load region, therefore, hydraulic efficiency of PAT is relatively low. It was observed that a relative eddy take place within the impeller passage, the eddy occurs near pressure side of blade at design-point condition, it motions to suction side at high discharge, and divides into two separated eddy at partial discharge condition. The relative eddy cause pressure fluctuate in PAT impeller, which affects the energy recovery of PAT.

scholarly journals Improvement Of Working Condition Through A Participatory Ergonomics Approach Decrease Low Back Pain Complaints And Increase The Productivity Of Tailors

2021 ◽  
Vol 1 (10) ◽  
Author(s):  
Fadma Putri ◽  
I Putu Gede Adiatmika ◽  
I Made Krisna Dinata
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Working Conditions ◽  
Working Condition ◽  
Sampling Period ◽  
Simple Random Sampling ◽  
Low Back ◽  
Participatory Ergonomics ◽  
Period 2 ◽  
Long Duration

Tailors work in a static position and bend over with a relatively long duration of workPostural muscle load on tailors results in the risk of complaints of low back pain which affects the productivity of tailor. The aim is to know the effect of improving working conditions through a participatory ergonomics approach to reduce low back pain complaints and increase tailor productivity.The method uses of experimental research with treatment by subject design, involving 9 samples selected by simple random sampling. Period 1 sample is working with conventional working conditions. Period 2 samples worked with improving working conditions through a participatory ergonomics approach. Washing out period and adaptation are given between the two periods. Complaints of low back pain were measured by the Oswestry Disability Index, while productivity was based on a comparison between the number of stitches/day and the score for complaints of low back pain per working time. The results showed that improving working conditions through a participatory ergonomics approach had a significant effect (p < 0.05). There was a decreasing in low back pain by 11.87% from an average of 48.67±1.73 to 42.89±1.76 and an increasing in productivity of 42.10% from an average of 0.038±0.004 to 0.054±0.005.

scholarly journals Condições de trabalho de enfermagem e adoecimento: motivos para a redução da jornada de trabalho para 30 horas

2012 ◽  
Vol 3 (4) ◽  
pp. 178-181 ◽  
Author(s):  
Vanda Elisa Andres Felli
Keyword(s):  
Quality Of Care ◽  
Occupational Health ◽  
Working Conditions ◽  
Working Condition ◽  
Work Hours ◽  
Work Absenteeism ◽  
Absence From Work ◽  
The Impact ◽  
Reflexive Analysis

O texto tem por objetivo fazer uma análise reflexiva sobre as condições de trabalho e adoecimento dos trabalhadores de enfermagem, determinadas por jornadas superiores a 30 horas. Partindo da análise do contexto do trabalho de enfermagem, o texto analisa as condições de trabalho e as suas implicações no adoecimento dos trabalhadores. Traz como consequências a diminuição da capacidade para o trabalho, o absenteísmo, a elevação de custos dos afastamentos, o impacto sobre o perfil de morbi-mortalidade dos trabalhadores e as implicações sobre a qualidade da assistência. Conclui-se que é necessário controlar a insalubridade, a periculosidade e a penosidade desse trabalho.Descritores: Enfermagem, Saúde do Trabalhador, Condições de Trabalho, Jornada de Trabalho, Morbidade.Nursing working condition and sickness: reasons why to reduce the work journey to 30 hoursThe text aims to do a reflexive analysis about the working conditions and sickness of nursing workers, determined for journeys exceeding 30 hours. Based on the analysis of the context of nursing work, the text examines the working conditions and their implications in illness among workers. Also, the text brings as consequences the decreased capacity to work, absenteeism, higher costs of absence from work, the impact on morbidity and mortality profile of workers and the implications on the quality of care. It is concluded that it is necessary to control the insalubrity, dangerousness and painfulness of this work.Descriptors: Nursing, Occupational Health, Working Conditions, Work Hours, Morbidity.Condiciones de trabajo de enfermería y enfermedad: motivos para la reducción de jornada para trabajar 30 horasEl texto tiene como objetivo analizar reflexivamente sobre las condiciones de trabajo y enfermedades de los trabajadores de enfermería, determinado por turnos que excedan 30 horas. Con base en el análisis del contexto del trabajo de enfermería, el texto analiza las condiciones de trabajo y sus implicaciones en la enfermedad entre los trabajadores. Trae consecuencias como la disminución de la capacidad de trabajo, ausentismo, costos más altos de las ausencias, el impacto en lo perfil de morbilidad y mortalidad de los trabajadores y las implicaciones en la calidad de la atención. Se concluye que es necesario controlar la insalubridad, peligrosidad y doloroso trabajo.Descriptores: Enfermería, Salud del Trabajador, Condiciones de Trabajo, Día de Trabajo, Morbidad.

Sign in / Sign up

Export Citation Format

Share Document