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A Study on Engine Life Span Based on Engine Assembly Quality Analysis
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作者 XU An-tao, LIU Xiang-kai, TANG Yan-feng, QIU Yi-long Maintenance Theory Staff Room, Military Traffic College, Tianjin 300161, P. R. China 《International Journal of Plant Engineering and Management》 2001年第2期83-86,共4页
In this paper, the main effective factors of engine assembly quality have been analyzed in detail. It provided a mathematical model of engine life span based on the laws of the changirng of friction pairs gap and runn... In this paper, the main effective factors of engine assembly quality have been analyzed in detail. It provided a mathematical model of engine life span based on the laws of the changirng of friction pairs gap and running-in analysis. On the basis of a EQ6100 engine test, the applied spectral analysis technique, it gained efficient technique measures to enhance the engine 's life span, and provided a proposal value and an allowed value of integrated position precision error. 展开更多
关键词 assembly quality position precision error
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Optimization of Fixture Number in Large Thin-Walled Parts Assembly Based on IPSO
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作者 Changhui Liu Jing Wang +3 位作者 Ying Zheng Ke Jin Jianbo Yu Jianfeng Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期213-227,共15页
There are lots of researches on fixture layout optimization for large thin-walled parts.Current researches focus on the positioning problem,i.e.,optimizing the positions of a constant number of fixtures.However,how to... There are lots of researches on fixture layout optimization for large thin-walled parts.Current researches focus on the positioning problem,i.e.,optimizing the positions of a constant number of fixtures.However,how to determine the number of fixtures is ignored.In most cases,the number of fixtures located on large thin-walled parts is determined based on engineering experience,which leads to huge fixture number and extra waste.Therefore,this paper constructs an optimization model to minimize the number of fixtures.The constraints are set in the optimization model to ensure that the part deformation is within the surface profile tolerance.In addition,the assembly gap between two parts is also controlled.To conduct the optimization,this paper develops an improved particle swarm optimization(IPSO)algorithm by integrating the shrinkage factor and adaptive inertia weight.In the algorithm,particles are encoded according to the fixture position.Each dimension of the particle is assigned to a sub-region by constraining the optional position range of each fixture to improve the optimization efficiency.Finally,a case study on ship curved panel assembly is provided to prove that our method can optimize the number of fixtures while meeting the assembly quality requirements.This research proposes a method to optimize the number of fixtures,which can reduce the number of fixtures and achieve deformation control at the same time. 展开更多
关键词 assembly quality Large thin-walled parts Fixture layout PSO FEM
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Analysis and Inverse Substructuring Computation on Dynamic Quality of Mechanical Assembly 被引量:3
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作者 Lü Guangqing YI Chuijie FANG Ke 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第3期539-548,共10页
Mechanical assembly has its own dynamic quality directly affecting the dynamic quality of whole product and should be considered in quality inspection and estimation of mechanical assembly. Based on functional relatio... Mechanical assembly has its own dynamic quality directly affecting the dynamic quality of whole product and should be considered in quality inspection and estimation of mechanical assembly. Based on functional relations between dynamic characteristics involved in mechanical assembly, the effects of assembling process on dynamic characteristics of substructural components of an assembly system are investigated by substructuring analysis. Assembly-coupling dynamic stiffness is clarified as the dominant factor of the effects and can be used as a quantitative measure of assembly dynamic quality. Two computational schemes using frequency response functions(FRFs) to determine the stiffness are provided and discussed by inverse substructuring analysis, including their applicable conditions and implementation procedure in application. Eigenvalue analysis on matrix-ratios of FRFs before and after assembling is employed and well validates the analytical outcomes and the schemes via both a lumped-parameter model and its analogic experimental counterpart. Applying the two schemes to inspect the dynamic quality provides the message of dynamic performance of the assembly system, and therefore improves conventional quality inspection and estimation of mechanical assembly in completeness. 展开更多
关键词 mechanical assembly dynamic quality substructuring analysis inverse substructuring assembly-coupling dynamic stiffness
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Development of Fixture Layout Optimization for Thin-Walled Parts:A Review
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作者 Changhui Liu Jing Wang +3 位作者 Binghai Zhou Jianbo Yu Ying Zheng Jianfeng Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第1期15-39,共25页
An increasing number of researchers have researched fixture layout optimization for thin-walled part assembly during the past decades.However,few papers systematically review these researches.By analyzing existing lit... An increasing number of researchers have researched fixture layout optimization for thin-walled part assembly during the past decades.However,few papers systematically review these researches.By analyzing existing literature,this paper summarizes the process of fixture layout optimization and the methods applied.The process of optimization is made up of optimization objective setting,assembly variation/deformation modeling,and fixture layout optimization.This paper makes a review of the fixture layout for thin-walled parts according to these three steps.First,two different kinds of optimization objectives are introduced.Researchers usually consider in-plane variations or out-of-plane deformations when designing objectives.Then,modeling methods for assembly variation and deformation are divided into two categories:Mechanism-based and data-based methods.Several common methods are discussed respectively.After that,optimization algorithms are reviewed systematically.There are two kinds of optimization algorithms:Traditional nonlinear programming and heuristic algorithms.Finally,discussions on the current situation are provided.The research direction of fixture layout optimization in the future is discussed from three aspects:Objective setting,improving modeling accuracy and optimization algorithms.Also,a new research point for fixture layout optimization is discussed.This paper systematically reviews the research on fixture layout optimization for thin-walled parts,and provides a reference for future research in this field. 展开更多
关键词 Thin-walled parts assembly quality Fixture layout optimization Modeling methods Optimization algorithms
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GAEP:a comprehensive genome assembly evaluating pipeline 被引量:6
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作者 Yong Zhang Hong-Wei Lu Jue Ruan 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2023年第10期747-754,共8页
With the rapid development of sequencing technologies,especially the maturity of third-generation sequencing technologies,there has been a significant increase in the number and quality of published genome assemblies.... With the rapid development of sequencing technologies,especially the maturity of third-generation sequencing technologies,there has been a significant increase in the number and quality of published genome assemblies.The emergence of these high-quality genomes has raised higher requirements for genome evaluation.Although numerous computational methods have been developed to evaluate assembly quality from various perspectives,the selective use of these evaluation methods can be arbitrary and inconvenient for fairly comparing the assembly quality.To address this issue,we have developed the Genome Assembly Evaluating Pipeline(GAEP),which provides a comprehensive assessment pipeline for evaluating genome quality from multiple perspectives,including continuity,completeness,and correctness.Additionally,GAEP includes new functions for detecting misassemblies and evaluating the assembly redundancy,which performs well in our testing.GAEP is publicly available at https://github.com/zyoptimistic/GAEP under the GPL3.0 License.With GAEP,users can quickly obtain accurate and reliable evaluation results,facilitating the comparison and selection of high-quality genome assemblies. 展开更多
关键词 Genome assembly assembly quality assembly metrics assembly evaluation pipeline Misassembly detection Misassembly breakpoint assembly redundancy
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A novel predict-prevention quality control method of multi-stage manufacturing process towards zero defect manufacturing 被引量:1
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作者 Li-Ping Zhao Bo-Hao Li Yi-Yong Yao 《Advances in Manufacturing》 SCIE EI CAS CSCD 2023年第2期280-294,共15页
Zero defection manufacturing (ZDM) is the pursuit of the manufacturing industry. However, there is a lack of the implementation method of ZDM in the multi-stage manufacturing process (MMP). Implementing ZDM and contro... Zero defection manufacturing (ZDM) is the pursuit of the manufacturing industry. However, there is a lack of the implementation method of ZDM in the multi-stage manufacturing process (MMP). Implementing ZDM and controlling product quality in MMP remains an urgent problem in intelligent manufacturing. A novel predict-prevention quality control method in MMP towards ZDM is proposed, including quality characteristics monitoring, key quality characteristics prediction, and assembly quality optimization. The stability of the quality characteristics is detected by analyzing the distribution of quality characteristics. By considering the correlations between different quality characteristics, a deep supervised long-short term memory (SLSTM) prediction network is built for time series prediction of quality characteristics. A long-short term memory-genetic algorithm (LSTM-GA) network is proposed to optimize the assembly quality. By utilizing the proposed quality control method in MMP, unqualified products can be avoided, and ZDM of MMP is implemented. Extensive empirical evaluations on the MMP of compressors validate the applicability and practicability of the proposed method. 展开更多
关键词 Zero defection manufacturing(ZDM) Multi-stage manufacturing process(MMP) Moving window Deep supervised long-short term memory(SLSTM)network assembly quality optimization
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Research on uncertainty in measurement assisted alignment in aircraft assembly 被引量:17
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作者 Chen Zhehan Du Fuzhou Tang Xiaoqing 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第6期1568-1576,共9页
Operations in assembling and joining large size aircraft components are changed to novel digital and flexible ways by digital measurement assisted alignment.Positions and orientations(P&O)of aligned components are ... Operations in assembling and joining large size aircraft components are changed to novel digital and flexible ways by digital measurement assisted alignment.Positions and orientations(P&O)of aligned components are critical characters which assure geometrical positions and relationships of those components.Therefore,evaluating the P&O of a component is considered necessary and critical for ensuring accuracy in aircraft assembly.Uncertainty of position and orientation(U-P&O),as a part of the evaluating result of P&O,needs to be given for ensuring the integrity and credibility of the result;furthermore,U-P&O is necessary for error tracing and quality evaluating of measurement assisted aircraft assembly.However,current research mainly focuses on the process integration of measurement with assembly,and usually ignores the uncertainty of measured result and its influence on quality evaluation.This paper focuses on the expression,analysis,and application of U-P&O in measurement assisted alignment.The geometrical and algebraical connotations of U-P&O are presented.Then,an analytical algorithm for evaluating the multi-dimensional U-P&O is given,and the effect factors and characteristics of U-P&O are discussed.Finally,U-P&O is used to evaluate alignment in aircraft assembly for quality evaluating and improving.Cases are introduced with the methodology. 展开更多
关键词 Aircraft manufacturing Large size components alignment Measurement assisted assembly quality assurance Uncertainty analysis Uncertainty of position and orientation
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The rational design of multiple molecular module-based assemblies for simultaneously improving rice yield and grain quality 被引量:6
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作者 Kun Wu Xiaopeng Xu +5 位作者 Nan Zhong Haixiang Huang Jianping Yu Yafeng Ye Yuejin Wu Xiangdong Fu 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2018年第6期337-341,共5页
Rice is one of the most important staple food for over half of the world's population,and a substantial increase in productivity and quality of rice grain will be required to feed a growing human population.Grain siz... Rice is one of the most important staple food for over half of the world's population,and a substantial increase in productivity and quality of rice grain will be required to feed a growing human population.Grain size and shape are the two important components contributing to grain yield and quality,because they impact both yield potential and end-use quality. 展开更多
关键词 The rational design of multiple molecular module-based assemblies for simultaneously improving rice yield and grain quality RIL length NIP
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