Under the paradigm of Industry 5.0,intelligent manufacturing transcends mere efficiency enhancement by emphasizing human-machine collaboration,where human expertise plays a central role in assembly processes.Despite a...Under the paradigm of Industry 5.0,intelligent manufacturing transcends mere efficiency enhancement by emphasizing human-machine collaboration,where human expertise plays a central role in assembly processes.Despite advancements in intelligent and digital technologies,assembly process design still heavily relies on manual knowledge reuse,and inefficiencies and inconsistent quality in process documentation are caused.To address the aforementioned issues,this paper proposes a knowledge push method of complex product assembly process design based on distillation model-based dynamically enhanced graph and Bayesian network.First,an initial knowledge graph is constructed using a BERT-BiLSTM-CRF model trained with integrated human expertise and a fine-tuned large language model.Then,a confidence-based dynamic weighted fusion strategy is employed to achieve dynamic incremental construction of the knowledge graph with low resource consumption.Subsequently,a Bayesian network model is constructed based on the relationships between assembly components,assembly features,and operations.Bayesian network reasoning is used to push assembly process knowledge under different design requirements.Finally,the feasibility of the Bayesian network construction method and the effectiveness of Bayesian network reasoning are verified through a specific example,significantly improving the utilization of assembly process knowledge and the efficiency of assembly process design.展开更多
This paper reports the reengineering of the assembly processes of printed circuit boards (PCBs) used in computers.The new designed assembly processes are quite different from the traditional ones,and the business perf...This paper reports the reengineering of the assembly processes of printed circuit boards (PCBs) used in computers.The new designed assembly processes are quite different from the traditional ones,and the business performance is dramatically improved through establishing parallel workstations,off line workstation,merging workstations and organizing a small teamwork who cooperates in stations.“ITHINK”,a software package of business process reengineering (BPR),was used to analyze the current processes and create new processes.ITHINK is a powerful tool of BPR in modeling business processes,“soft” variables and conducting sensitivity analysis.The new assembly processes were tested over a period of 8 hours simulation.The results show that the new processes can increase throughput by 80% with only requiring less additional resources.The throughput can increase further by 17.5% when a small teamwork cooperates in some stations.展开更多
The assembly process of aerospace products such as satellites and rockets has the characteristics of single-or small-batch production,a long development period,high reliability,and frequent disturbances.How to predict...The assembly process of aerospace products such as satellites and rockets has the characteristics of single-or small-batch production,a long development period,high reliability,and frequent disturbances.How to predict and avoid quality abnormalities,quickly locate their causes,and improve product assembly quality and efficiency are urgent engineering issues.As the core technology to realize the integration of virtual and physical space,digital twin(DT)technology can make full use of the low cost,high efficiency,and predictable advantages of digital space to provide a feasible solution to such problems.Hence,a quality management method for the assembly process of aerospace products based on DT is proposed.Given that traditional quality control methods for the assembly process of aerospace products are mostly post-inspection,the Grey-Markov model and T-K control chart are used with a small sample of assembly quality data to predict the value of quality data and the status of an assembly system.The Apriori algorithm is applied to mine the strong association rules related to quality data anomalies and uncontrolled assembly systems so as to solve the issue that the causes of abnormal quality are complicated and difficult to trace.The implementation of the proposed approach is described,taking the collected centroid data of an aerospace product’s cabin,one of the key quality data in the assembly process of aerospace products,as an example.A DT-based quality management system for the assembly process of aerospace products is developed,which can effectively improve the efficiency of quality management for the assembly process of aerospace products and reduce quality abnormalities.展开更多
The rotor initial unbalance of an aeroengine gas generator of turboshaft engine seriously affects rotor assembly process.To reasonably optimize rotor assembly process,the effect analyses of rotor initial unbalance of ...The rotor initial unbalance of an aeroengine gas generator of turboshaft engine seriously affects rotor assembly process.To reasonably optimize rotor assembly process,the effect analyses of rotor initial unbalance of single disc and combined discs on rotor dynamic characteristics are firstly implemented in respect of the dispersity of rotor initial unbalance.It is found that the most important factors contributing to rotor vibration are the unbalances of the first stage compressor disc and the second stage turbine disc.However,reducing the mass of two discs conflicts with the control of the whole gas generator rotor balance resulting from the unbalance increase of single components.Thus,we further analyze the key control factors of affecting rotor initial unbalance,and give the strict control measures of centrifugal impeller runout in the assembly process by adjusting the angle of central tie rod axis.The purpose of this measures to make the assembly process simpler and more effective for timely controlling rotor initial unbalance.The efforts of this study validate that the proposed method is workable for the rotor tightened by a central tie rod and possesses the significant meaning of practical application in engineering.展开更多
Computer-aided block assembly process planning based on rule-reasoning are developed in order to improve the assembly efficiency and implement the automated block assembly process planning generation in shipbuilding. ...Computer-aided block assembly process planning based on rule-reasoning are developed in order to improve the assembly efficiency and implement the automated block assembly process planning generation in shipbuilding. First, weighted directed liaison graph （WDLG） is proposed to represent the model of block assembly process according to the characteristics of assembly relation, and edge list （EL） is used to describe assembly sequences. Shapes and assembly attributes of block parts are analyzed to determine the assembly position and matched parts of parts used frequently. Then, a series of assembly rules are generalized, and assembly sequences for block are obtained by means of rule reasoning. Final, a prototype system of computer-aided block assembly process planning is built. The system has been tested on actual block, and the results were found to be quite efficiency. Meanwhile, the fundament for the automation of block assembly process generation and integration with other systems is established.展开更多
Assembly process documents record the designers'intention or knowledge.However,common knowl-edge extraction methods are not well suitable for assembly process documents,because of its tabular form and unstructured...Assembly process documents record the designers'intention or knowledge.However,common knowl-edge extraction methods are not well suitable for assembly process documents,because of its tabular form and unstructured natural language texts.In this paper,an assembly semantic entity recognition and relation con-struction method oriented to assembly process documents is proposed.First,the assembly process sentences are extracted from the table through concerned region recognition and cell division,and they will be stored as a key-value object file.Then,the semantic entities in the sentence are identified through the sequence tagging model based on the specific attention mechanism for assembly operation type.The syntactic rules are designed for realizing automatic construction of relation between entities.Finally,by using the self-constructed corpus,it is proved that the sequence tagging model in the proposed method performs better than the mainstream named entity recognition model when handling assembly process design language.The effectiveness of the proposed method is also analyzed through the simulation experiment in the small-scale real scene,compared with manual method.The results show that the proposed method can help designers accumulate knowledge automatically and efficiently.展开更多
To analyze the physical structure of assembly process and assure product quality, the quality stability of multi-station assembly process was investigated. First, the assembly process was modeled as a one-dimensional ...To analyze the physical structure of assembly process and assure product quality, the quality stability of multi-station assembly process was investigated. First, the assembly process was modeled as a one-dimensional discrete variant system by state space equation based on variation stream. Then, the criterion to judge whether the process is stable or not and the index, stability degree, to show the level of stability were proposed by analyzing the bounded-input bounded-output (BIBO) stability of system. Finally, a simulated example of a sheet metal assembly process with three stations, was provided to verify the effectiveness of the proposed method.展开更多
Assembly process planning(APP)for complicated products is a time-consuming and difficult work with conventional method.Virtual assembly process planning(VAPP)provides engineers a new and efficiency way.Previous studie...Assembly process planning(APP)for complicated products is a time-consuming and difficult work with conventional method.Virtual assembly process planning(VAPP)provides engineers a new and efficiency way.Previous studies in VAPP are almost isolated and dispersive,and have not established a whole understanding and discussed key realization techniques of VAPP from a systemic and integrated view.The integrated virtual assembly process planning(IVAPP)system is a new virtual reality based engineering application,which offers engineers an efficient,intuitive,immersive and integrated method for assembly process planning in a virtual environment.Based on analysis the information integration requirement of VAPP,the architecture of IVAPP is proposed.Through the integrated structure,IVAPP system can realize information integration and workflow controlling.In order to mode/the assembly process in IVAPP,a hierarchical assembly task list(HATL)is presented,in which different assembly tasks for assembling different components are organized into a hierarchical list.A process-oriented automatic geometrical constraint recognition algorithm(AGCR)is proposed,so that geometrical constraints between components can be automatically recognized during the process of interactive assembling.At the same time,a progressive hierarchical reasoning(PHR)model is discussed.AGCR and PHR will greatly reduce the interactive workload.A discrete control node model(DCNM)for cable harness assembly planning in IVAPP is detailed.DCNM converts a cable harness into continuous flexed line segments connected by a series of section center points,and designs can realize cable harness planning through controlling those control nodes.Mechanical assemblies(such as transmission case and engine of automobile)are used to illustrate the feasibility of the proposed method and algorithms.The application of IVAPP system reveals advantages over the traditional assembly process planning method in shortening the time-consumed in assembly planning and in minimizing the handling difficulty,excessive reorientation and dissimilarity of assembly operations.展开更多
This paper describes the implementation and performance of the virtual assembly support sys-tem (VASS), a new system that can provide designers and assembly process engineers with a simulation and visualization enviro...This paper describes the implementation and performance of the virtual assembly support sys-tem (VASS), a new system that can provide designers and assembly process engineers with a simulation and visualization environment where they can evaluate the assemblability/disassemblability of products, and thereby use a computer to intuitively create assembly plans and interactively generate assembly process charts. Subassembly planning and assembly priority reasoning techniques were utilized to find heuristic information to improve the efficiency of assembly process planning. Tool planning was imple-mented to consider tool requirements in the product design stage. New methods were developed to reduce the computation amount involved in interference checking. As an important feature of the VASS, human interaction was integrated into the whole process of assembly process planning, extending the power of computer reasoning by including human expertise, resulting in better assembly plans and better designs.展开更多
Urban soils harbor billions of bacterial cells and millions of species.However,the distribution patterns and assembly processes of bacterial communities remain largely uncharacterized in urban soils.It is also unknown...Urban soils harbor billions of bacterial cells and millions of species.However,the distribution patterns and assembly processes of bacterial communities remain largely uncharacterized in urban soils.It is also unknown if we can use the bacteria to track soil sources to certain cities and districts.Here,Illumina MiSeq sequencing was used to survey soil bacterial communities from 529 random plots spanning 61 districts and 10 major cities in China.Over a 3,000 km range,community similarity declined with increasing geographic distance(Mantel r=0.62),and community composition was clustered by city(R^(2)=0.50).Within cities(<100 km),the aforementioned biogeographic patterns were weakened.Process analysis showed that homogenizing dispersal and dispersal limitation dominated soil bacterial assembly at small and large spatial scales,respectively.Accordingly,the probabilities of accurately tracking random soil sources to certain cities and districts were 90.0% and 66.7%,respectively.When the tested samples originated from cities that were more than 1,265 km apart,the soil sources could be identified with nearly 100% accuracy.Overall,this study demonstrates the strong distance-decay relationship and the clear geographic zoning of urban soil bacterial communities among cities.The varied importance of different community assembly processes at multiple spatial scales strongly affects the accuracy of microbial source tracking.展开更多
●Soil erosion resulted in homogenization of bacterial communities in the watershed.●Microbial community heterogeneity among erosion sites made soil tracing possible.●Assembly process results showed that the trackin...●Soil erosion resulted in homogenization of bacterial communities in the watershed.●Microbial community heterogeneity among erosion sites made soil tracing possible.●Assembly process results showed that the tracking results can achieve high precision.●Dryland was the main source of sediment deposition based on the result of FEAST.Sediment source tracing can accurately provide a theoretical basis for controlling soil erosion effectively,by identifying the most serious types of land use.Traditional sediment tracing methods are based on physical,chemical,biological,and composite fingerprinting,which have not included microbes.As high-throughput sequencing becomes more prevalent,microorganisms can provide more information than what we think.Thus,whether the microorganism can also be used as a special fingerprint factor for sediment source identification during soil erosion,we have tested it by using microbial source tracking tool FEAST to quantify the microbe contribution from five types of eroded land(including dryland,urban,paddy field,forest and grassland)to the depositional areas(Niubitan)in the Yuanjiang basin.The source microbial community in the erosive area was heterogeneous,and assembly process analysis further demonstrated that the source tracking results could reach higher accuracy.The results of FEAST showed that dryland(35.50%),urban(17.21%),paddy field(8.14%),and forest(1.07%)were the major contributors to Niubitan.Our results follow the general soil erosion rules and prove its validity.Taken together,a new perspective is provided by these results for tracing sediment sources in erosion-sedimentary systems.展开更多
Reductive soil disinfestation(RSD)is an important tool for sustainable agricultural productivity.However,the differences in soil bacterial communities and their community assembly processes among RSD and other treatme...Reductive soil disinfestation(RSD)is an important tool for sustainable agricultural productivity.However,the differences in soil bacterial communities and their community assembly processes among RSD and other treatment strategies(e.g.,biochar and chemical fumigation)are still subject to open questions.In this study,soils subjected to various treatments–un-treated control(CK),chemical soil fumigation with CaCN_(2)(CF),1% biochar(1%B),3% biochar(3%B),and reductive soil disinfestation(RSD)are investigated.Soil samples were collected,incubated,and then used for growth of tomato plants.The Sloan neutral community model indicates that stochastic processes dominate in bacterial community assembly for both biochar and CF amendments.In contrast,this work shows that RSD treatment can have a strong impact on soil bacterial community composition.The relative abundance of Firmicutes increased during unplanted soil incubation,whereas Proteobacteria and Bacteroidetes dominated in the rhizosphere after planting of tomatoes.Normalized stochasticity ratio reveals that deterministic selection played an important role in the bacterial assembly under RSD amendment.We found that RSD amendment yielded lower biomass than that for other treatments after 28 days of tomato growth.Our results suggest that although RSD treatment has great potential to rebuild soil bacterial ecology by shaping bacterial communities and their assembly processes,it is important to monitor and manage soil conditions(e.g.,soil nutrients or physical properties)before planting to ensure plant productivity.展开更多
Soil microbiomes are significant for biodiversity,crucial for ecosystem functions,and vital for the health of various organisms.Nevertheless,the impacts of season and plant species shifts on soil microbial diversity a...Soil microbiomes are significant for biodiversity,crucial for ecosystem functions,and vital for the health of various organisms.Nevertheless,the impacts of season and plant species shifts on soil microbial diversity and community assembly are still poorly understood.This study explored soil bacterial,fungal,and protistan communities during summer and winter in a coastal wetland affected by Spartina alterniflora invasion and subsequent Cyperus malaccensis or Kandelia obovata restoration.The results showed that bacterial,fungal,and protistan diversity were 2.63%,40.3%,and 9.90%higher in winter than in summer,respectively.Plant species had a distinct impact on microbial diversity.Notably,K.obovata restoration significantly increased bacterial diversity,but decreased protistan diversity,with no effect on fungal diversity when compared to S.alterniflora invasion.Season and plant species both significantly influenced the community structure of bacteria,fungi,and protists.However,protistan community structure was more sensitive to season compared to the structure of bacterial and fungal communities.The complexity of co-occurrence networks within or among bacteria,fungi,and protists was higher in winter than in summer.Bacterial and protistan community assembly was primarily driven by stochastic processes,while fungal assembly was dominated by deterministic processes.Bacterial and protistan community assembly exhibited lower stochasticity in winter compared to summer,suggesting a more deterministic assembly of communities during winter.Our findings highlight the critical role of season and plant species in regulating microbial communities,revealing higher microbial diversity,network complexity,and determinism in community assembly during winter compared to summer in a subtropical coastal wetland.展开更多
phoD and pqqC gene occurrence in bacteria allows them to mobilize phosphorus(P)by mineralizing organic P(Po)and solubilizing inorganic P(Pi),respectively.Community characteristics of phoD-and pqqC-harboring bacteria(p...phoD and pqqC gene occurrence in bacteria allows them to mobilize phosphorus(P)by mineralizing organic P(Po)and solubilizing inorganic P(Pi),respectively.Community characteristics of phoD-and pqqC-harboring bacteria(phoD-and pqqC-HB,respectively)mediate P cycling.However,whether the microbial community assembly and keystone taxa of phoD-and pqqC-HB regulate P availability and distinct regulatory pathways between these two genes remain unclear.In this study,soil microbial community characteristics and P availability were investigated in four long-term(38-year)fertilization regimes:control with no fertilizer(CK),P fertilizer(PF),nitrogen(N)and P fertilizers(NP),and N fertilizer,P fertilizer,and manure(NPM).The N addition treatments(NP and NPM)significantly changed the community composition and increased the abundances of phoD-and pqqC-HB compared to the no-N addition treatments(CK and PF).Stochastic processes dominated the community assembly of both phoD-and pqqC-HB,and the relative contributions of stochasticity increased with N addition.Furthermore,the N addition treatments resulted in greater network complexity and higher abundances of keystone taxa of phoD-and pqqC-HB compared to those of the no-N addition treatments.The keystone taxa implicated in P cycling were also associated with carbon(C)and N cycling processes.Microbial community composition and assembly processes were the main factors driving labile Pi for phoD-HB,whereas keystone taxa contributed the most to labile Pi for pqqC-HB.These results emphasize that distinct mechanisms of phoD-and pqqC-HB regulate P availability under fertilization management and underline the significance of microbial community assembly and keystone taxa in soil ecological functions,offering fresh perspectives on comprehending the biological processes facilitated by microorganisms in enhancing soil quality.展开更多
Bacterial communities play a crucial role in permafrost biogeochemical cycling and ecosystem function maintenance.Bacterial interaction is one of the main factors in shaping soil bacterial communities.However,how woul...Bacterial communities play a crucial role in permafrost biogeochemical cycling and ecosystem function maintenance.Bacterial interaction is one of the main factors in shaping soil bacterial communities.However,how would bacterial interaction influence the bacterial communities in permafrost of the Qinghai-Tibet Plateau(QTP)remains largely unknown.Here we collected paired soil samples from both the active and permafrost layers of two typical QTP permafrost regions in October 2020 for Tuotuohe River(TTH)and May 2022 for Aerjin(ARJ),and investigated the bacterial communities and the role of interactions in structuring the bacterial community and its assembly process through amplicon sequencing of the 16S rRNA gene.Our study revealed distinct bacterial communities,with significant differences in the relative abundances of Proteobacteria(P<0.05),Acidobacteriota(P<0.001),Bacteroidota(P<0.05),and Planctomycetota(P<0.001)between the active layer and the permafrost layer.More importantly,we found that interspecies interactions,including both positive and negative associations,were strongly correlated with bacterial alpha-diversity and played a significant role in community variation and assembly process.Our findings also showed that the community assembly in both the active and permafrost layers was primarily driven by homogeneous selection of deterministic processes,with interspecies interactions accounting for more than 58%and 63%of all assembly mechanisms,respectively.This is the first study to quantify the contribution of bacterial interactions in shaping the bacterial community and its assembly process in permafrost of QTP,highlighting the importance of considering interspecies interactions in future modeling efforts.Our work also emphasizes the necessity of including interspecies interactions in microbial process projections to reduce uncertainty.展开更多
Wheat-maize(WM)and wheat-soybean(WS)double-cropping rotation systems are predominant in the North China Plain,with implications for national agricultural output and sustainability.As rotation systems exert legacy effe...Wheat-maize(WM)and wheat-soybean(WS)double-cropping rotation systems are predominant in the North China Plain,with implications for national agricultural output and sustainability.As rotation systems exert legacy effects on soil health and crop productivity,the role of crop rotation in shaping the root-associated microbiome of the succeeding crops has emerged as a pivotal aspect of crop management research.Here,the effects of the preceding two cycles of WM and WS rotations on the recruitment and filtering of wheat root-associated bacterial communities across wheat developmental stages were investigated.Our results revealed that bacterial community diversity and composition were primarily influenced by compartment and developmental stage,while the preceding rotation systems had a slight but significant effect on wheat root-associated bacterial communities.The co-occurrence networks under WM were more complex in the wheat rhizosphere and rhizoplane,with the operational taxonomic units(OTUs)related to cellulolysis showing greater connectivity.The co-occurrence networks under WS were simple but stable in the rhizosphere and complex in the rhizoplane and endosphere,with the OTUs related to ureolysis and nitrogen fixation showing greater connectivity.While both stochastic and deterministic processes contributed to the assembly of wheat root-associated bacterial communities,the contributions of deterministic processes under WS were 19.4-38.5%higher than those under the WM rotation across the root-associated compartments,indicating the substantial impact of a soybean legacy effect on wheat root selection of microbes.Plant growthpromoting rhizobacteria with the potential to fix nitrogen,produce indole-3-acetic acid,and inhibit diseases such as Betaproteobacteriales,Azospirillales and Dyella sp.,were identified within the OTUs that were consistently enriched across all the wheat root-associated compartments and developmental stages,which were also important predictors of wheat yield.This study elucidates the role of crop rotation in modulating the dynamics of crop root-associated bacterial communities,and underscores the potential of targeted microbiome manipulation for optimizing wheat production and enhancing soil health.展开更多
Odd-numbered and high-nuclearity coordination clusters are extremely rare,yet they represent an intriguing subclass lacking regular repeating building blocks and high structural symmetry for understanding self-assembl...Odd-numbered and high-nuclearity coordination clusters are extremely rare,yet they represent an intriguing subclass lacking regular repeating building blocks and high structural symmetry for understanding self-assembled multiatomic systems.Herein,the largest cobalt and polydentate ligand based cluster featuring odd-nuclearity,namely[Co_(19)(HL1)_(8)(L1)_(12)(L′)_(2)(Ac)_(4)]·10CH_(3)CH_(2)OH·6H_(2)O(1,H_(2)L1=1H-benzo[d]imidazole-2-yl)methanol,HL'=1H-benzo[d]imidazole),was obtained with in-situ ligand transformation from H_(2)L1 to L′.It features a hierarchical trilayer and void-cage inside structure,consisting of central disc-shaped[Co_(7)L_(10)]core with two[Co_(6)]rings on both sides.ESI-MS of crystal 1 yields a series of more than sixteen fragments,all featuring an integrated[Co_(19)]core,suggesting stability of the polynuclear cluster in solution.During increased in-source energy from 0 to 100 eV,all MS peaks shifted to a lower m/z range,but the[Co_(19)]core remained intact,excepting for the stepwise elimination of up to three Ac^(−)anions or three L1 linkers.PXRD tracking of the reaction sediments showed the formation of a key precursor of[Co_(4)L_(4)]cubane at 3 h,and its content decreased at 6 h and vanished at 12 h,followed by the appearance of crystals 1 by the generation of a clear solution at 18 h,suggesting an initial cluster assembly-disassembly process.ESI-MS spectra analysis of both reaction sediment and solution further identify the existence of other crucial higher-nuclearity reassembled fragments of[Co_(7)L_(10)]disk and its expansion of[Co_(13)L_(12)(L′)_(2)].A probable tandem assembly-disassembly-reassembly mechanism is put forward as[CoL_(2)]→[Co_(4)L_(4)]→[Co_(7)L_(10)]→[Co_(13)L_(12)(L′)_(2)]→[Co_(19)L_(2)0(L′)_(2)].Their evolution also indicated the ingenious synergy of coexisting organic,inorganic and in-situ generated ligands,along with diverse coordination geometries of metal ions,plays a directional role in forming odd-numbered and high-nuclearity coordination clusters.Magnetism analysis revealed antiferromagnetic coupling plays dominated role in the cluster.展开更多
Focusing on the study of the components of mechanical rotational body,the data structure and algorithm of component model generation are discussed.Some problems in assembly process of 3 dimensional graph of component...Focusing on the study of the components of mechanical rotational body,the data structure and algorithm of component model generation are discussed.Some problems in assembly process of 3 dimensional graph of components are studied in great detail.展开更多
The layout and assembly of flexible cables play important roles in the design and development of complex electromechanical products.The rationality of cable layout design and the reliability of cable assembly greatly ...The layout and assembly of flexible cables play important roles in the design and development of complex electromechanical products.The rationality of cable layout design and the reliability of cable assembly greatly affect product quality.In this paper,we review the methods of cable layout design,cable assembly process planning,and cable assembly simulation.We first review research on flexible cable layout design(both interactive and automatic).Then,research on the cable assembly process planning,including cable assembly path and manipulation planning,is reviewed.Finally,cable assembly simulation is introduced,which includes general cable information,cable collision detection data,and cable assembly process modeling.Current problems and future research directions are summarized at the end of the paper.展开更多
There are heterogeneous problems between the CAD model and the assembly process document.In the planning stage of assembly process,these heterogeneous problems can decrease the efficiency of information interaction.Ba...There are heterogeneous problems between the CAD model and the assembly process document.In the planning stage of assembly process,these heterogeneous problems can decrease the efficiency of information interaction.Based on knowledge graph,this paper proposes an assembly information model(KGAM)to integrate geometric information from CAD model,non-geometric information and semantic information from assembly process document.KGAM describes the integrated assembly process information as a knowledge graph in the form of“entity-relationship-entity”and“entity-attribute-value”,which can improve the efficiency of information interaction.Taking the trial assembly stage of a certain type of aeroengine compressor rotor component as an example,KGAM is used to get its assembly process knowledge graph.The trial data show the query and update rate of assembly attribute information is improved by more than once.And the query and update rate of assembly semantic information is improved by more than twice.In conclusion,KGAM can solve the heterogeneous problems between the CAD model and the assembly process document and improve the information interaction efficiency.展开更多
基金Supported by National Key Research and Development Program(Grant No.2024YFB3312700)National Natural Science Foundation of China(Grant No.52405541)the Changzhou Municipal Sci&Tech Program(Grant No.CJ20241131)。
文摘Under the paradigm of Industry 5.0,intelligent manufacturing transcends mere efficiency enhancement by emphasizing human-machine collaboration,where human expertise plays a central role in assembly processes.Despite advancements in intelligent and digital technologies,assembly process design still heavily relies on manual knowledge reuse,and inefficiencies and inconsistent quality in process documentation are caused.To address the aforementioned issues,this paper proposes a knowledge push method of complex product assembly process design based on distillation model-based dynamically enhanced graph and Bayesian network.First,an initial knowledge graph is constructed using a BERT-BiLSTM-CRF model trained with integrated human expertise and a fine-tuned large language model.Then,a confidence-based dynamic weighted fusion strategy is employed to achieve dynamic incremental construction of the knowledge graph with low resource consumption.Subsequently,a Bayesian network model is constructed based on the relationships between assembly components,assembly features,and operations.Bayesian network reasoning is used to push assembly process knowledge under different design requirements.Finally,the feasibility of the Bayesian network construction method and the effectiveness of Bayesian network reasoning are verified through a specific example,significantly improving the utilization of assembly process knowledge and the efficiency of assembly process design.
基金Supported by NSFC (No.79770 0 63) and Natural Sciences and En-gineering Research Council of Canada
文摘This paper reports the reengineering of the assembly processes of printed circuit boards (PCBs) used in computers.The new designed assembly processes are quite different from the traditional ones,and the business performance is dramatically improved through establishing parallel workstations,off line workstation,merging workstations and organizing a small teamwork who cooperates in stations.“ITHINK”,a software package of business process reengineering (BPR),was used to analyze the current processes and create new processes.ITHINK is a powerful tool of BPR in modeling business processes,“soft” variables and conducting sensitivity analysis.The new assembly processes were tested over a period of 8 hours simulation.The results show that the new processes can increase throughput by 80% with only requiring less additional resources.The throughput can increase further by 17.5% when a small teamwork cooperates in some stations.
基金National Key Research and Development Program of China(Grant No.2020YFB1710300)National Natural Science Foundation of China(Grant No.52005042)+2 种基金National Defense Fundamental Research Foundation of China(Grant No.JCKY2020203B039)Equipment Pre-research Foundation of China(Grant No.80923010101)Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘The assembly process of aerospace products such as satellites and rockets has the characteristics of single-or small-batch production,a long development period,high reliability,and frequent disturbances.How to predict and avoid quality abnormalities,quickly locate their causes,and improve product assembly quality and efficiency are urgent engineering issues.As the core technology to realize the integration of virtual and physical space,digital twin(DT)technology can make full use of the low cost,high efficiency,and predictable advantages of digital space to provide a feasible solution to such problems.Hence,a quality management method for the assembly process of aerospace products based on DT is proposed.Given that traditional quality control methods for the assembly process of aerospace products are mostly post-inspection,the Grey-Markov model and T-K control chart are used with a small sample of assembly quality data to predict the value of quality data and the status of an assembly system.The Apriori algorithm is applied to mine the strong association rules related to quality data anomalies and uncontrolled assembly systems so as to solve the issue that the causes of abnormal quality are complicated and difficult to trace.The implementation of the proposed approach is described,taking the collected centroid data of an aerospace product’s cabin,one of the key quality data in the assembly process of aerospace products,as an example.A DT-based quality management system for the assembly process of aerospace products is developed,which can effectively improve the efficiency of quality management for the assembly process of aerospace products and reduce quality abnormalities.
文摘The rotor initial unbalance of an aeroengine gas generator of turboshaft engine seriously affects rotor assembly process.To reasonably optimize rotor assembly process,the effect analyses of rotor initial unbalance of single disc and combined discs on rotor dynamic characteristics are firstly implemented in respect of the dispersity of rotor initial unbalance.It is found that the most important factors contributing to rotor vibration are the unbalances of the first stage compressor disc and the second stage turbine disc.However,reducing the mass of two discs conflicts with the control of the whole gas generator rotor balance resulting from the unbalance increase of single components.Thus,we further analyze the key control factors of affecting rotor initial unbalance,and give the strict control measures of centrifugal impeller runout in the assembly process by adjusting the angle of central tie rod axis.The purpose of this measures to make the assembly process simpler and more effective for timely controlling rotor initial unbalance.The efforts of this study validate that the proposed method is workable for the rotor tightened by a central tie rod and possesses the significant meaning of practical application in engineering.
基金National Natural Science Foundation of China (No.40606018)
文摘Computer-aided block assembly process planning based on rule-reasoning are developed in order to improve the assembly efficiency and implement the automated block assembly process planning generation in shipbuilding. First, weighted directed liaison graph （WDLG） is proposed to represent the model of block assembly process according to the characteristics of assembly relation, and edge list （EL） is used to describe assembly sequences. Shapes and assembly attributes of block parts are analyzed to determine the assembly position and matched parts of parts used frequently. Then, a series of assembly rules are generalized, and assembly sequences for block are obtained by means of rule reasoning. Final, a prototype system of computer-aided block assembly process planning is built. The system has been tested on actual block, and the results were found to be quite efficiency. Meanwhile, the fundament for the automation of block assembly process generation and integration with other systems is established.
文摘Assembly process documents record the designers'intention or knowledge.However,common knowl-edge extraction methods are not well suitable for assembly process documents,because of its tabular form and unstructured natural language texts.In this paper,an assembly semantic entity recognition and relation con-struction method oriented to assembly process documents is proposed.First,the assembly process sentences are extracted from the table through concerned region recognition and cell division,and they will be stored as a key-value object file.Then,the semantic entities in the sentence are identified through the sequence tagging model based on the specific attention mechanism for assembly operation type.The syntactic rules are designed for realizing automatic construction of relation between entities.Finally,by using the self-constructed corpus,it is proved that the sequence tagging model in the proposed method performs better than the mainstream named entity recognition model when handling assembly process design language.The effectiveness of the proposed method is also analyzed through the simulation experiment in the small-scale real scene,compared with manual method.The results show that the proposed method can help designers accumulate knowledge automatically and efficiently.
基金Supported bythe National High-Tech Research and Development Plan (National"863"Plan) (No2006AA04Z115)Tianjin Science andTechnology Key Project (No05YFGDGX08700)
文摘To analyze the physical structure of assembly process and assure product quality, the quality stability of multi-station assembly process was investigated. First, the assembly process was modeled as a one-dimensional discrete variant system by state space equation based on variation stream. Then, the criterion to judge whether the process is stable or not and the index, stability degree, to show the level of stability were proposed by analyzing the bounded-input bounded-output (BIBO) stability of system. Finally, a simulated example of a sheet metal assembly process with three stations, was provided to verify the effectiveness of the proposed method.
基金supported by National Natural Science Foundation of China(Grant No.50805009)The Eleventh Five Year Plan Defense Pre-Research Fund,China(Grant No.51318010205)
文摘Assembly process planning(APP)for complicated products is a time-consuming and difficult work with conventional method.Virtual assembly process planning(VAPP)provides engineers a new and efficiency way.Previous studies in VAPP are almost isolated and dispersive,and have not established a whole understanding and discussed key realization techniques of VAPP from a systemic and integrated view.The integrated virtual assembly process planning(IVAPP)system is a new virtual reality based engineering application,which offers engineers an efficient,intuitive,immersive and integrated method for assembly process planning in a virtual environment.Based on analysis the information integration requirement of VAPP,the architecture of IVAPP is proposed.Through the integrated structure,IVAPP system can realize information integration and workflow controlling.In order to mode/the assembly process in IVAPP,a hierarchical assembly task list(HATL)is presented,in which different assembly tasks for assembling different components are organized into a hierarchical list.A process-oriented automatic geometrical constraint recognition algorithm(AGCR)is proposed,so that geometrical constraints between components can be automatically recognized during the process of interactive assembling.At the same time,a progressive hierarchical reasoning(PHR)model is discussed.AGCR and PHR will greatly reduce the interactive workload.A discrete control node model(DCNM)for cable harness assembly planning in IVAPP is detailed.DCNM converts a cable harness into continuous flexed line segments connected by a series of section center points,and designs can realize cable harness planning through controlling those control nodes.Mechanical assemblies(such as transmission case and engine of automobile)are used to illustrate the feasibility of the proposed method and algorithms.The application of IVAPP system reveals advantages over the traditional assembly process planning method in shortening the time-consumed in assembly planning and in minimizing the handling difficulty,excessive reorientation and dissimilarity of assembly operations.
基金Supported by the National High-Tech Research and Development (863) Program of China (Nos. 863-511-910-405 and 863-511-030-003)
文摘This paper describes the implementation and performance of the virtual assembly support sys-tem (VASS), a new system that can provide designers and assembly process engineers with a simulation and visualization environment where they can evaluate the assemblability/disassemblability of products, and thereby use a computer to intuitively create assembly plans and interactively generate assembly process charts. Subassembly planning and assembly priority reasoning techniques were utilized to find heuristic information to improve the efficiency of assembly process planning. Tool planning was imple-mented to consider tool requirements in the product design stage. New methods were developed to reduce the computation amount involved in interference checking. As an important feature of the VASS, human interaction was integrated into the whole process of assembly process planning, extending the power of computer reasoning by including human expertise, resulting in better assembly plans and better designs.
基金supported by the National Key Research and Development Program of China(2017YFC0803803)the National Natural Science Foundation of China(41907039)。
文摘Urban soils harbor billions of bacterial cells and millions of species.However,the distribution patterns and assembly processes of bacterial communities remain largely uncharacterized in urban soils.It is also unknown if we can use the bacteria to track soil sources to certain cities and districts.Here,Illumina MiSeq sequencing was used to survey soil bacterial communities from 529 random plots spanning 61 districts and 10 major cities in China.Over a 3,000 km range,community similarity declined with increasing geographic distance(Mantel r=0.62),and community composition was clustered by city(R^(2)=0.50).Within cities(<100 km),the aforementioned biogeographic patterns were weakened.Process analysis showed that homogenizing dispersal and dispersal limitation dominated soil bacterial assembly at small and large spatial scales,respectively.Accordingly,the probabilities of accurately tracking random soil sources to certain cities and districts were 90.0% and 66.7%,respectively.When the tested samples originated from cities that were more than 1,265 km apart,the soil sources could be identified with nearly 100% accuracy.Overall,this study demonstrates the strong distance-decay relationship and the clear geographic zoning of urban soil bacterial communities among cities.The varied importance of different community assembly processes at multiple spatial scales strongly affects the accuracy of microbial source tracking.
基金The National Natural Science Foundation of China provided funding for this project(U19A2047).
文摘●Soil erosion resulted in homogenization of bacterial communities in the watershed.●Microbial community heterogeneity among erosion sites made soil tracing possible.●Assembly process results showed that the tracking results can achieve high precision.●Dryland was the main source of sediment deposition based on the result of FEAST.Sediment source tracing can accurately provide a theoretical basis for controlling soil erosion effectively,by identifying the most serious types of land use.Traditional sediment tracing methods are based on physical,chemical,biological,and composite fingerprinting,which have not included microbes.As high-throughput sequencing becomes more prevalent,microorganisms can provide more information than what we think.Thus,whether the microorganism can also be used as a special fingerprint factor for sediment source identification during soil erosion,we have tested it by using microbial source tracking tool FEAST to quantify the microbe contribution from five types of eroded land(including dryland,urban,paddy field,forest and grassland)to the depositional areas(Niubitan)in the Yuanjiang basin.The source microbial community in the erosive area was heterogeneous,and assembly process analysis further demonstrated that the source tracking results could reach higher accuracy.The results of FEAST showed that dryland(35.50%),urban(17.21%),paddy field(8.14%),and forest(1.07%)were the major contributors to Niubitan.Our results follow the general soil erosion rules and prove its validity.Taken together,a new perspective is provided by these results for tracing sediment sources in erosion-sedimentary systems.
基金funded by the National Natural Science Foundation of China(42167017)Talents of Guizhou Science and Technology Cooperation Platform([2017]5726-52)+2 种基金Guizhou Province 100-level Talent Project([2020]6010)the Key Program of Science and Technology of Guizhou Province([2020]1Z036)Ningbo Municipal Science and Technology Bureau([2021]Z047).
文摘Reductive soil disinfestation(RSD)is an important tool for sustainable agricultural productivity.However,the differences in soil bacterial communities and their community assembly processes among RSD and other treatment strategies(e.g.,biochar and chemical fumigation)are still subject to open questions.In this study,soils subjected to various treatments–un-treated control(CK),chemical soil fumigation with CaCN_(2)(CF),1% biochar(1%B),3% biochar(3%B),and reductive soil disinfestation(RSD)are investigated.Soil samples were collected,incubated,and then used for growth of tomato plants.The Sloan neutral community model indicates that stochastic processes dominate in bacterial community assembly for both biochar and CF amendments.In contrast,this work shows that RSD treatment can have a strong impact on soil bacterial community composition.The relative abundance of Firmicutes increased during unplanted soil incubation,whereas Proteobacteria and Bacteroidetes dominated in the rhizosphere after planting of tomatoes.Normalized stochasticity ratio reveals that deterministic selection played an important role in the bacterial assembly under RSD amendment.We found that RSD amendment yielded lower biomass than that for other treatments after 28 days of tomato growth.Our results suggest that although RSD treatment has great potential to rebuild soil bacterial ecology by shaping bacterial communities and their assembly processes,it is important to monitor and manage soil conditions(e.g.,soil nutrients or physical properties)before planting to ensure plant productivity.
基金supported by the Natural Resources Science and Technology Innovation Project of Fujian Province,China(No.KY-090000-04-2022-012)the National Natural Science Foundation of China(Nos.42077041 and 42377301)+1 种基金the National Natural Science Foundation of Fujian Province,China(No.2021J011038)the Talent Introduction Program of Minjiang University,China(No.MJY20012).
文摘Soil microbiomes are significant for biodiversity,crucial for ecosystem functions,and vital for the health of various organisms.Nevertheless,the impacts of season and plant species shifts on soil microbial diversity and community assembly are still poorly understood.This study explored soil bacterial,fungal,and protistan communities during summer and winter in a coastal wetland affected by Spartina alterniflora invasion and subsequent Cyperus malaccensis or Kandelia obovata restoration.The results showed that bacterial,fungal,and protistan diversity were 2.63%,40.3%,and 9.90%higher in winter than in summer,respectively.Plant species had a distinct impact on microbial diversity.Notably,K.obovata restoration significantly increased bacterial diversity,but decreased protistan diversity,with no effect on fungal diversity when compared to S.alterniflora invasion.Season and plant species both significantly influenced the community structure of bacteria,fungi,and protists.However,protistan community structure was more sensitive to season compared to the structure of bacterial and fungal communities.The complexity of co-occurrence networks within or among bacteria,fungi,and protists was higher in winter than in summer.Bacterial and protistan community assembly was primarily driven by stochastic processes,while fungal assembly was dominated by deterministic processes.Bacterial and protistan community assembly exhibited lower stochasticity in winter compared to summer,suggesting a more deterministic assembly of communities during winter.Our findings highlight the critical role of season and plant species in regulating microbial communities,revealing higher microbial diversity,network complexity,and determinism in community assembly during winter compared to summer in a subtropical coastal wetland.
基金supported by the National Key Research and Development Program of China(No.2022YFD 1901601)the National Natural Science Foundation of China(No.42107360)the Fundamental Research Funds for the Central Universities,China(No.2452021032).
文摘phoD and pqqC gene occurrence in bacteria allows them to mobilize phosphorus(P)by mineralizing organic P(Po)and solubilizing inorganic P(Pi),respectively.Community characteristics of phoD-and pqqC-harboring bacteria(phoD-and pqqC-HB,respectively)mediate P cycling.However,whether the microbial community assembly and keystone taxa of phoD-and pqqC-HB regulate P availability and distinct regulatory pathways between these two genes remain unclear.In this study,soil microbial community characteristics and P availability were investigated in four long-term(38-year)fertilization regimes:control with no fertilizer(CK),P fertilizer(PF),nitrogen(N)and P fertilizers(NP),and N fertilizer,P fertilizer,and manure(NPM).The N addition treatments(NP and NPM)significantly changed the community composition and increased the abundances of phoD-and pqqC-HB compared to the no-N addition treatments(CK and PF).Stochastic processes dominated the community assembly of both phoD-and pqqC-HB,and the relative contributions of stochasticity increased with N addition.Furthermore,the N addition treatments resulted in greater network complexity and higher abundances of keystone taxa of phoD-and pqqC-HB compared to those of the no-N addition treatments.The keystone taxa implicated in P cycling were also associated with carbon(C)and N cycling processes.Microbial community composition and assembly processes were the main factors driving labile Pi for phoD-HB,whereas keystone taxa contributed the most to labile Pi for pqqC-HB.These results emphasize that distinct mechanisms of phoD-and pqqC-HB regulate P availability under fertilization management and underline the significance of microbial community assembly and keystone taxa in soil ecological functions,offering fresh perspectives on comprehending the biological processes facilitated by microorganisms in enhancing soil quality.
基金supported by grants from the National Natural Science Foundation of China for Excellent Young Scientists Fund Program(No.42222105)the National Natural Science Foundation of China General Program(No.42171144)+1 种基金the Assessment of Ecosystem Carbon Stock and Turnover Patterns in Qinghai Province(No.2021-SFA7-1-1)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(No.2021QZKK0100)。
文摘Bacterial communities play a crucial role in permafrost biogeochemical cycling and ecosystem function maintenance.Bacterial interaction is one of the main factors in shaping soil bacterial communities.However,how would bacterial interaction influence the bacterial communities in permafrost of the Qinghai-Tibet Plateau(QTP)remains largely unknown.Here we collected paired soil samples from both the active and permafrost layers of two typical QTP permafrost regions in October 2020 for Tuotuohe River(TTH)and May 2022 for Aerjin(ARJ),and investigated the bacterial communities and the role of interactions in structuring the bacterial community and its assembly process through amplicon sequencing of the 16S rRNA gene.Our study revealed distinct bacterial communities,with significant differences in the relative abundances of Proteobacteria(P<0.05),Acidobacteriota(P<0.001),Bacteroidota(P<0.05),and Planctomycetota(P<0.001)between the active layer and the permafrost layer.More importantly,we found that interspecies interactions,including both positive and negative associations,were strongly correlated with bacterial alpha-diversity and played a significant role in community variation and assembly process.Our findings also showed that the community assembly in both the active and permafrost layers was primarily driven by homogeneous selection of deterministic processes,with interspecies interactions accounting for more than 58%and 63%of all assembly mechanisms,respectively.This is the first study to quantify the contribution of bacterial interactions in shaping the bacterial community and its assembly process in permafrost of QTP,highlighting the importance of considering interspecies interactions in future modeling efforts.Our work also emphasizes the necessity of including interspecies interactions in microbial process projections to reduce uncertainty.
基金the National Natural Science Foundation of China(42107339)the China Agriculture Research System(CARS-04)。
文摘Wheat-maize(WM)and wheat-soybean(WS)double-cropping rotation systems are predominant in the North China Plain,with implications for national agricultural output and sustainability.As rotation systems exert legacy effects on soil health and crop productivity,the role of crop rotation in shaping the root-associated microbiome of the succeeding crops has emerged as a pivotal aspect of crop management research.Here,the effects of the preceding two cycles of WM and WS rotations on the recruitment and filtering of wheat root-associated bacterial communities across wheat developmental stages were investigated.Our results revealed that bacterial community diversity and composition were primarily influenced by compartment and developmental stage,while the preceding rotation systems had a slight but significant effect on wheat root-associated bacterial communities.The co-occurrence networks under WM were more complex in the wheat rhizosphere and rhizoplane,with the operational taxonomic units(OTUs)related to cellulolysis showing greater connectivity.The co-occurrence networks under WS were simple but stable in the rhizosphere and complex in the rhizoplane and endosphere,with the OTUs related to ureolysis and nitrogen fixation showing greater connectivity.While both stochastic and deterministic processes contributed to the assembly of wheat root-associated bacterial communities,the contributions of deterministic processes under WS were 19.4-38.5%higher than those under the WM rotation across the root-associated compartments,indicating the substantial impact of a soybean legacy effect on wheat root selection of microbes.Plant growthpromoting rhizobacteria with the potential to fix nitrogen,produce indole-3-acetic acid,and inhibit diseases such as Betaproteobacteriales,Azospirillales and Dyella sp.,were identified within the OTUs that were consistently enriched across all the wheat root-associated compartments and developmental stages,which were also important predictors of wheat yield.This study elucidates the role of crop rotation in modulating the dynamics of crop root-associated bacterial communities,and underscores the potential of targeted microbiome manipulation for optimizing wheat production and enhancing soil health.
基金supported by the BAGUI Talent Program in Guangxi Province(No.2019AC26001)the National Natural Science Foundation of China(Nos.22171075,U23A2080,22371173).
文摘Odd-numbered and high-nuclearity coordination clusters are extremely rare,yet they represent an intriguing subclass lacking regular repeating building blocks and high structural symmetry for understanding self-assembled multiatomic systems.Herein,the largest cobalt and polydentate ligand based cluster featuring odd-nuclearity,namely[Co_(19)(HL1)_(8)(L1)_(12)(L′)_(2)(Ac)_(4)]·10CH_(3)CH_(2)OH·6H_(2)O(1,H_(2)L1=1H-benzo[d]imidazole-2-yl)methanol,HL'=1H-benzo[d]imidazole),was obtained with in-situ ligand transformation from H_(2)L1 to L′.It features a hierarchical trilayer and void-cage inside structure,consisting of central disc-shaped[Co_(7)L_(10)]core with two[Co_(6)]rings on both sides.ESI-MS of crystal 1 yields a series of more than sixteen fragments,all featuring an integrated[Co_(19)]core,suggesting stability of the polynuclear cluster in solution.During increased in-source energy from 0 to 100 eV,all MS peaks shifted to a lower m/z range,but the[Co_(19)]core remained intact,excepting for the stepwise elimination of up to three Ac^(−)anions or three L1 linkers.PXRD tracking of the reaction sediments showed the formation of a key precursor of[Co_(4)L_(4)]cubane at 3 h,and its content decreased at 6 h and vanished at 12 h,followed by the appearance of crystals 1 by the generation of a clear solution at 18 h,suggesting an initial cluster assembly-disassembly process.ESI-MS spectra analysis of both reaction sediment and solution further identify the existence of other crucial higher-nuclearity reassembled fragments of[Co_(7)L_(10)]disk and its expansion of[Co_(13)L_(12)(L′)_(2)].A probable tandem assembly-disassembly-reassembly mechanism is put forward as[CoL_(2)]→[Co_(4)L_(4)]→[Co_(7)L_(10)]→[Co_(13)L_(12)(L′)_(2)]→[Co_(19)L_(2)0(L′)_(2)].Their evolution also indicated the ingenious synergy of coexisting organic,inorganic and in-situ generated ligands,along with diverse coordination geometries of metal ions,plays a directional role in forming odd-numbered and high-nuclearity coordination clusters.Magnetism analysis revealed antiferromagnetic coupling plays dominated role in the cluster.
文摘Focusing on the study of the components of mechanical rotational body,the data structure and algorithm of component model generation are discussed.Some problems in assembly process of 3 dimensional graph of components are studied in great detail.
基金the National Defense Fundamental Research Foundation of China(JCKY2017204B502,JCKY2016204A502)and National Natural Science Foundation of China(51935003).
文摘The layout and assembly of flexible cables play important roles in the design and development of complex electromechanical products.The rationality of cable layout design and the reliability of cable assembly greatly affect product quality.In this paper,we review the methods of cable layout design,cable assembly process planning,and cable assembly simulation.We first review research on flexible cable layout design(both interactive and automatic).Then,research on the cable assembly process planning,including cable assembly path and manipulation planning,is reviewed.Finally,cable assembly simulation is introduced,which includes general cable information,cable collision detection data,and cable assembly process modeling.Current problems and future research directions are summarized at the end of the paper.
基金the National Natural Science Foundation of China(No.51805079)。
文摘There are heterogeneous problems between the CAD model and the assembly process document.In the planning stage of assembly process,these heterogeneous problems can decrease the efficiency of information interaction.Based on knowledge graph,this paper proposes an assembly information model(KGAM)to integrate geometric information from CAD model,non-geometric information and semantic information from assembly process document.KGAM describes the integrated assembly process information as a knowledge graph in the form of“entity-relationship-entity”and“entity-attribute-value”,which can improve the efficiency of information interaction.Taking the trial assembly stage of a certain type of aeroengine compressor rotor component as an example,KGAM is used to get its assembly process knowledge graph.The trial data show the query and update rate of assembly attribute information is improved by more than once.And the query and update rate of assembly semantic information is improved by more than twice.In conclusion,KGAM can solve the heterogeneous problems between the CAD model and the assembly process document and improve the information interaction efficiency.
