The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have bec...The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have become a pivotal production tool in this context.Since the arm span of a single robot usually does not exceed 3 meters,it is not competent for producing large-scale building components.Accordingly,the extension of the robot,s working range is often achieved by external axes.Nevertheless,the coupling control of external axes and robots and their kinematic solution have become key challenges.The primary technical difficulties include customized construction robots,automatic solutions for external axes,fixed axis joints,and specific motion mode control.This paper proposes solutions to these difficulties,introduces the relevant basic concepts and algorithms in detail,and encapsulates these robotics principles and algorithm processes into the Grasshopper plug-in commonly used by architects to form the FURobot software platform.This platform effectively solves the above problems,lowers the threshold for architects,and improves production efficiency.The effectiveness of the algorithm and software in this paper is verified through simulation experiments.展开更多
Shock wave caused by a sudden release of high-energy,such as explosion and blast,usually affects a significant range of areas.The utilization of a uniform fine mesh to capture sharp shock wave and to obtain precise re...Shock wave caused by a sudden release of high-energy,such as explosion and blast,usually affects a significant range of areas.The utilization of a uniform fine mesh to capture sharp shock wave and to obtain precise results is inefficient in terms of computational resource.This is particularly evident when large-scale fluid field simulations are conducted with significant differences in computational domain size.In this work,a variable-domain-size adaptive mesh enlargement(vAME)method is developed based on the proposed adaptive mesh enlargement(AME)method for modeling multi-explosives explosion problems.The vAME method reduces the division of numerous empty areas or unnecessary computational domains by adaptively suspending enlargement operation in one or two directions,rather than in all directions as in AME method.A series of numerical tests via AME and vAME with varying nonintegral enlargement ratios and different mesh numbers are simulated to verify the efficiency and order of accuracy.An estimate of speedup ratio is analyzed for further efficiency comparison.Several large-scale near-ground explosion experiments with single/multiple explosives are performed to analyze the shock wave superposition formed by the incident wave,reflected wave,and Mach wave.Additionally,the vAME method is employed to validate the accuracy,as well as to investigate the performance of the fluid field and shock wave propagation,considering explosive quantities ranging from 1 to 5 while maintaining a constant total mass.The results show a satisfactory correlation between the overpressure versus time curves for experiments and numerical simulations.The vAME method yields a competitive efficiency,increasing the computational speed to 3.0 and approximately 120,000 times in comparison to AME and the fully fine mesh method,respectively.It indicates that the vAME method reduces the computational cost with minimal impact on the results for such large-scale high-energy release problems with significant differences in computational domain size.展开更多
The paper presents a design method that ensures the ingenuity of the product form as well as the whole and exact expression of user’s needs. The key idea is to establish an automatic design system which can transform...The paper presents a design method that ensures the ingenuity of the product form as well as the whole and exact expression of user’s needs. The key idea is to establish an automatic design system which can transform the user’s language needs into the product features in real-time. A rifle was taken as a research instance and soldiers were chosen as evaluation customers. The theory of fuzzy set and semantic difference are adopted to evaluate the relationship between user’s needs and product features as well as their alternatives. FAHP (fuzzy analytic hierarchy process) is utilized to judge the user’s satisfactory forms. This method can also be applied to other product form designs.展开更多
The decentralized robust guaranteed cost control problem is studied for a class of interconnected singular large-scale systems with time-delay and norm-bounded time-invariant parameter uncertainty under a given quadra...The decentralized robust guaranteed cost control problem is studied for a class of interconnected singular large-scale systems with time-delay and norm-bounded time-invariant parameter uncertainty under a given quadratic cost performance function. The problem that is addressed in this study is to design a decentralized robust guaranteed cost state feedback controller such that the closed-loop system is not only regular, impulse-free and stable, but also guarantees an adequate level of performance for all admissible uncertainties. A sufficient condition for the existence of the decentralized robust guaranteed cost state feedback controllers is proposed in terms of a linear matrix inequality （LMI） via LMI approach. When this condition is feasible, the desired state feedback decentralized robust guaranteed cost controller gain matrices can be obtained. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed approach.展开更多
A group of graphical models and mathematical models a re used to describe the methods of mass customization (MC). The relationships am ong the models and methods are shown in Fig.1. Fig.1 Relationships among optimizat...A group of graphical models and mathematical models a re used to describe the methods of mass customization (MC). The relationships am ong the models and methods are shown in Fig.1. Fig.1 Relationships among optimization methods for MCThe methods for MC relate to both of product and process, also customized quanti ty and deepness. The methods for MC are integrated by the work in the paper, whi ch can help to understand and use MC better. The optimization and standardization of product is the key for MC. Increasing op timization breadth in product family can help to decrease the customization quan tity in every section of production process. Increasing optimization deepness in products family can help to move the CODCP backward in production process. At the same time, the optimization and standardization of product is the key to reduce cost of customized product. The optimization of the integration of pr oduct and process is the key to reduce lead time of customized product.展开更多
The temperature control of the large-scale vertical quench furnace is very difficult due to its huge volume and complex thermal exchanges. To meet the technical requirement of the quenching process, a temperature cont...The temperature control of the large-scale vertical quench furnace is very difficult due to its huge volume and complex thermal exchanges. To meet the technical requirement of the quenching process, a temperature control system which integrates temperature calibration and temperature uniformity control is developed for the thermal treatment of aluminum alloy workpieces in the large-scale vertical quench furnace. To obtain the aluminum alloy workpiece temperature, an air heat transfer model is newly established to describe the temperature gradient distribution so that the immeasurable workpiece temperature can be calibrated from the available thermocouple temperature. To satisfy the uniformity control of the furnace temperature, a second order partial differential equation(PDE) is derived to describe the thermal dynamics inside the vertical quench furnace. Based on the PDE, a decoupling matrix is constructed to solve the coupling issue and decouple the heating process into multiple independent heating subsystems. Then, using the expert control rule to find a compromise of temperature rising time and overshoot during the quenching process. The developed temperature control system has been successfully applied to a 31 m large-scale vertical quench furnace, and the industrial running results show the significant improvement of the temperature uniformity, lower overshoot and shortened processing time.展开更多
Numerical analysis of the optimal supporting time and long-term stability index of the surrounding rocks in the underground plant of Xiangjiaba hydro-power station was carried out based on the rheological theory. Firs...Numerical analysis of the optimal supporting time and long-term stability index of the surrounding rocks in the underground plant of Xiangjiaba hydro-power station was carried out based on the rheological theory. Firstly,the mechanical parameters of each rock group were identified from the experimental data; secondly,the rheological calculation and analysis for the cavern in stepped excavation without supporting were made; finally,the optimal time for supporting at the characteristic point in a typical section was obtained while the creep rate and displacement after each excavation step has satisfied the criterion of the optimal supporting time. Excavation was repeated when the optimal time for supporting was identified,and the long-term stability creep time and the maximum creep deformation of the characteristic point were determined in accordance with the criterion of long-term stability index. It is shown that the optimal supporting time of the characteristic point in the underground plant of Xiangjiaba hydro-power station is 5-8 d,the long-term stability time of the typical section is 126 d,and the corresponding largest creep deformation is 24.30 mm. While the cavern is supported,the cavern deformation is significantly reduced and the stress states of the surrounding rock masses are remarkably improved.展开更多
An optimal tracking control （OTC） problem for linear time-delay large-scale systems affected by external persistent disturbances is investigated. Based on the internal model principle, a disturbance compensator is c...An optimal tracking control （OTC） problem for linear time-delay large-scale systems affected by external persistent disturbances is investigated. Based on the internal model principle, a disturbance compensator is constructed. The system with persistent disturbances is transformed into an augmented system without persistent disturbances. The original OTC problem of linear time-delay system is transformed into a sequence of linear two- point boundary value （TPBV） problems by introducing a sensitivity parameter and expanding Maclaurin series around it. By solving an OTC law of the augmented system, the OTC law of the original system is obtained. A numerical simulation is provided to illustrate the effectiveness of the proposed method.展开更多
Decentralized robust stabilization problem of discrete-time fuzzy large-scale systems with parametric uncertainties is considered. This uncertain fuzzy large-scale system consists of N interconnected T-S fuzzy subsyst...Decentralized robust stabilization problem of discrete-time fuzzy large-scale systems with parametric uncertainties is considered. This uncertain fuzzy large-scale system consists of N interconnected T-S fuzzy subsystems, and the parametric uncertainties are unknown but norm-bounded. Based on Lyapunov stability theory and decentralized control theory of large-scale system, the design schema of decentralized parallel distributed compensation （DPDC） fuzzy controllers to ensure the asymptotic stability of the whole fuzzy large-scale system is proposed. The existence conditions for these controllers take the forms of LMIs. Finally a numerical simulation example is given to show the utility of the method proposed.展开更多
Based on the explicit finite element(FE) method and platform of ABAQUS,considering both the inhomogeneity of soils and concave-convex fluctuation of topography,a large-scale refined two-dimensional(2D) FE nonlinear an...Based on the explicit finite element(FE) method and platform of ABAQUS,considering both the inhomogeneity of soils and concave-convex fluctuation of topography,a large-scale refined two-dimensional(2D) FE nonlinear analytical model for Fuzhou Basin was established.The peak ground motion acceleration(PGA) and focusing effect with depth were analyzed.Meanwhile,the results by wave propagation of one-dimensional(1D) layered medium equivalent linearization method were added for contrast.The results show that:1) PGA at different depths are obviously amplified compared to the input ground motion,amplification effect of both funnel-shaped depression and upheaval areas(based on the shape of bedrock surface) present especially remarkable.The 2D results indicate that the PGA displays a non-monotonic decreasing with depth and a greater focusing effect of some particular layers,while the 1D results turn out that the PGA decreases with depth,except that PGA at few particular depth increases abruptly; 2) To the funnel-shaped depression areas,PGA amplification effect above 8 m depth shows relatively larger,to the upheaval areas,PGA amplification effect from 15 m to 25 m depth seems more significant.However,the regularities of the PGA amplification effect could hardly be found in the rest areas; 3) It appears a higher regression rate of PGA amplification coefficient with depth when under a smaller input motion; 4) The frequency spectral characteristic of input motion has noticeable effects on PGA amplification tendency.展开更多
This paper focuses on the problem of non-fragile decentralized guaranteed cost control for uncertain neutral large-scale interconnected systems with time-varying delays in state,control input and interconnections.A no...This paper focuses on the problem of non-fragile decentralized guaranteed cost control for uncertain neutral large-scale interconnected systems with time-varying delays in state,control input and interconnections.A novel scheme,viewing the interconnections with time-varying delays as effective information but not disturbances,is developed.Based on Lyapunov stability theory,using various techniques of decomposing and magnifying matrices,a design method of the non-fragile decentralized guaranteed cost controller for unperturbed neutral large-scale interconnected systems is proposed and the guaranteed cost is presented.The further results are derived for the uncertain case from the criterion of unperturbed neutral large-scale interconnected systems.Finally,an illustrative example shows that the results are significantly better than the existing results in the literatures.展开更多
The most common apparatus used to investigate the load-deformation parameters of homogeneous fine-grained soils is a Casagrande-type oedometer. A typical Casagrande oedometer cell has an internal diameter of 76 mm and...The most common apparatus used to investigate the load-deformation parameters of homogeneous fine-grained soils is a Casagrande-type oedometer. A typical Casagrande oedometer cell has an internal diameter of 76 mm and a height of 19 mm.However, the dimensions of this kind of apparatus do not meet the requirements of some civil engineering applications like studying load-deformation characteristics of specimens with large-diameter particles such as granular materials or municipal solid waste materials. Therefore, it is decided to design and develop a large-scale oedometer with an internal diameter of 490 mm. The new apparatus provides the possibility to evaluate the load-deformation characteristics of soil specimens with different diameter to height ratios. The designed apparatus is able to measure the coefficient of lateral earth pressure at rest. The details and capabilities of the developed oedometer are provided and discussed. To study the performance and efficiency, a number of consolidation tests were performed on Firoozkoh No. 161 sand using the newly developed large scale oedometer made and also the 50 mm diameter Casagrande oedometer. Benchmark test results show that measured consolidation parameters by large scale oedometer are comparable to values measured by Casagrande type oedometer.展开更多
Networked customization had gradually become one of t he import manufacturing and marketing patterns in the information age. Product d escription had an important effect on realizing networked customization. From th i...Networked customization had gradually become one of t he import manufacturing and marketing patterns in the information age. Product d escription had an important effect on realizing networked customization. From th is point of view, this paper firstly analyzed four requirements of adaptability, stability, conciseness and definitude that product description methods for netw orked customization must satisfy. According to these requirements, the paper com mented on current methods of product description, pointing out their advantages and disadvantages. As none of current methods could satisfy the four requirement s simultaneously, they were not fully applicable to networked customization. The n a plug-in based product description method was brought forward and discussed in detail. In this method, product description for networked customization w as abstracted as three component parts of basic description, basic feature and c ustomization feature. These parts had different characteristics. Basic descripti on was applicable to all products types. Basic feature was stable as concerning specific product type. Variants of certain product type all possessed identi cal basic features. Customization features were variable. Different combinations of customization features would give birth to different product variants. Apply ing object-oriented method, three standard product description plug-ins could be got by encapsulating these component parts. As "basic feature" and "customiza tion feature" plug-in had similar structures, they could be further abstracted as "feature" plug-in. When describing a type of product, a "basic description" plug-in would be instantiated firstly. Then according to product’s specific ch aracteristics, necessary number of "basic feature" and "customization feature" p lug-ins would be instantiated and appended, such as "color", "material", etc. E ach "basic feature" plug-in related to an instantiated "feature value" plug-in , while each "customization feature" plug-in related to one or multiple instant iated "feature value" plug-ins. Finally, "associate" and "exclude" relation ship should be specified among associated "customization feature" plug-ins. Thr ough appending and combining various plug-ins, this method was capable of descr ibing any type of product while meeting the four requirements simultaneously. Th is paper also gave an example to clarify the application of plug-in based produ ct description method. This example firstly described a kind of customizable TV provided by certain company. Then it showed how to describe an individual co nfiguration of this customizable TV in XML. Furthermore, suppose a consumer want ed to search for relevant information of a TV with game function, this example explained how to utilize XML query language to benefit consumer’s searching for product information. From analysis, we could draw the conclusion that plug -in based product description method was superior to current description method s and fully adapted to networked customization environment.展开更多
Based on introduction characteristics and classific at ion of Mass Customization (MC), the paper expounds foundations and design me thods of MC. The foundations of MC production are standardization, seriation and norm...Based on introduction characteristics and classific at ion of Mass Customization (MC), the paper expounds foundations and design me thods of MC. The foundations of MC production are standardization, seriation and normality of production, guiding thought of Concurrent Engineering (CE), ap plication of CAD/CAM technology and etc. And design methods of MC products are d esign for product family, modular design, parameterization CAD, variant design, design for manufacturing (DFM) and design by customers. Design for product famil y is a method that first to design a basic form of the product, and then to with draw variant parameters to become a variable product model, makes a family or a series of product design at the same time. Modular design is that based on produ ct function analysis of different function or the same function but different sp ecification within a certain scope, divides and designs out a series of function modular, and through selection and combination of the modular can make up diffe rent products. Parameterization CAD is a CAD method that has function of dimensi on drive. Variant design is a method that under circumstance of keeping principl e constant and construction similar or likeness, properly adjusts part of constr uction and design parameters to adapt design demands. DFM demands the designer t o consider problems that will appear in manufacture in the stage of design, and to avoid them through optimal design. And design by customers is guiding custome rs to design within the scope of production capacity of enterprise and optional items that enterprise has designed to satisfy their requirements of form, functi on and price. Among them modular design, parameterization CAD and variant design are key technology of design methods of MC products. And design by customers is a main characteristic of design of customization product, and an effective sale means also.展开更多
Mass Customization (MC) is one of the importance en te rprise produces modes in information age progressively. Mass Customization produ ct manufacturing is aimed at the objection of agile responding to customer deman ...Mass Customization (MC) is one of the importance en te rprise produces modes in information age progressively. Mass Customization produ ct manufacturing is aimed at the objection of agile responding to customer deman d, market changing and market opportunities to combine with modern management te chnology and advanced manufacture technology, and to use the development model o f design for product family and technology concurrent. Therefore, in the environ ment of market continuing to change with a high speed, MC enterprise is required to raise its ability of controlling future market by improving its "agility of product manufacturing". So it is necessary to research about the question of agi lity evaluation of MC product manufacturing. Base on the characteristics of the Mass Customization (MC) product manufacturing and the requirement of the agile m anufacturing, this paper establish an MC product manufacturing Agility evaluatio n index system through studying MC enterprise’s organization management agility evaluation and MC products design agility evaluation and MC manufacture agility evaluation. Also, with Xi Dian Casting limited company as an example, the multi -grade fuzzy assessment method is used to evaluate its agility.展开更多
In the view of the comparison of Mass Customization ( MC) with Mass Production and Customization Production, the objectives of MC are analyzed. It is pointed out that the core objectives of MC are to realize in dividu...In the view of the comparison of Mass Customization ( MC) with Mass Production and Customization Production, the objectives of MC are analyzed. It is pointed out that the core objectives of MC are to realize in dividuation customization, low cost, quick response to market demands. The modul arization theory is simply introduced. Based on the characteristics of modular ization, the mechanism of realizing MC with modularization is analyzed. The in dividuation customization can be realized with the different combinations of mod ules. The low cost can be realized with the scale economy and the category econo my of modules. The quick response can be realized with standard modules and its interfaces. So, the modularization is a kind of effective method in realizing MC . The modularization for MC is a systems engineering. With product modularized, production organization and management and manufacturing equipment will be chang ed. In addition, the paper also proposes a Mass Customization production model w hich is based on modularization. This Mass Customization production model is con sisted of modularization of product design, specialization of manufacturing, Vir tual Enterprises based on modularizing enterprises, and modularizing manufacturi ng equipment. The module design for MC, modularizing enterprises, and reconfigur able automation manufacturing equipment are discussed, and it is pointed out tha t they are the important supports for MC.展开更多
Model Order Reduction (MOR) plays more and more imp or tant role in complex system simulation, design and control recently. For example , for the large-size space structures, VLSI and MEMS (Micro-ElectroMechanical Sys...Model Order Reduction (MOR) plays more and more imp or tant role in complex system simulation, design and control recently. For example , for the large-size space structures, VLSI and MEMS (Micro-ElectroMechanical Systems) etc., in order to shorten the development cost, increase the system co ntrolling accuracy and reduce the complexity of controllers, the reduced order model must be constructed. Even in Virtual Reality (VR), the simulation and d isplay must be in real-time, the model order must be reduced too. The recent advances of MOR research are overviewed in the article. The MOR theor y and methods may be classified as Singular Value decomposition (SVD) based, the Krylov subspace based and others. The merits and demerits of the different meth ods are analyzed, and the existed problems are pointed out. Moreover, the applic ation’s fields are overviewed, and the potential applications are forecaste d. After the existed problems analyzed, the future work is described. There are som e problems in the traditional methods such as SVD and Krylov subspace, they are that it’s difficult to (1)guarantee the stability of the original system, (2) b e adaptive to nonlinear system, and (3) control the modeling accuracy. The f uture works may be solving the above problems on the foundation of the tradition al methods, and applying other methods such as wavelet or signal compression.展开更多
The developing status of world large-scale methanol production technology is analyzed and Linda's JW low-pressure methanol synthesis reactor with uniform temperature is described. JW serial reactors have been succ...The developing status of world large-scale methanol production technology is analyzed and Linda's JW low-pressure methanol synthesis reactor with uniform temperature is described. JW serial reactors have been successfully introduced in and applied in Harbin Gasification Plant and the productivity has been increased by 50% and now nine sets of equipments are successfully running in Harbin Gasification Plant,Jiangsu Xinya, Shandong Kenli,Henan Zhongyuan, Handan Xinyangguang,' Shanxi Weihua and Inner Mongolia Tianye. Now it has manufacturing the reactors of 300,000 t/a for Liaoning Dahua. Some solutions for the structure problems of 1000 ～5000 t/d methanol synthesis rectors are put forward.展开更多
The problem of partial stability is investigated for a class of continuous-time large-scale systems. Under assumption that the null solution of the isolated subsystems is stable, based on decomposition-aggregation met...The problem of partial stability is investigated for a class of continuous-time large-scale systems. Under assumption that the null solution of the isolated subsystems is stable, based on decomposition-aggregation methods and Lyapunov second method, some theorems concerning the globally partial asymptotic stability and globally partial exponential stability are obtained via utilizing the inequality analysis technique and comparison technique. Finally, an example is presented to illustrate the results.展开更多
In this paper, we presented a method of using the l as er scanning triangulation for the non-contact 3D surface profile measurement of large-scale object. The characteristic of large-scale object non-contact mea surem...In this paper, we presented a method of using the l as er scanning triangulation for the non-contact 3D surface profile measurement of large-scale object. The characteristic of large-scale object non-contact mea surement is analyzed and the measuring method is proposed. Main factors influenc ing measurement precision such as image distortion and accurate designation of s peckle center are analyzed and methods of solving these problems are proposed. W e designed a combined filter by which the pulse noise and the Gaussian noise of speckle image can be eliminated efficiently. Using the characteristic of intensi ty distribution of laser speckle image we proposed a new approximating method th at could locate the center of laser speckle image at sub-pixel. The auxiliary v ariables are set to linearize the relationship between the image displacement an d the distance, the accurate values of laser triangulation system parameters cou ld be calibrated accurately and the measuring precision is increased remarkabl y. Using the above techniques we designed a measuring system based on laser sc anning triangulation. The results of the experiment show that these methods can raise the measuring precision of large-scale 3D surface profile effectively.展开更多
基金National Key R&D Program of China(Nos.2023YFC3806900,2022YFE0141400)。
文摘The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have become a pivotal production tool in this context.Since the arm span of a single robot usually does not exceed 3 meters,it is not competent for producing large-scale building components.Accordingly,the extension of the robot,s working range is often achieved by external axes.Nevertheless,the coupling control of external axes and robots and their kinematic solution have become key challenges.The primary technical difficulties include customized construction robots,automatic solutions for external axes,fixed axis joints,and specific motion mode control.This paper proposes solutions to these difficulties,introduces the relevant basic concepts and algorithms in detail,and encapsulates these robotics principles and algorithm processes into the Grasshopper plug-in commonly used by architects to form the FURobot software platform.This platform effectively solves the above problems,lowers the threshold for architects,and improves production efficiency.The effectiveness of the algorithm and software in this paper is verified through simulation experiments.
基金supported by the National Natural Science Foundation of China(Grant Nos.12302435 and 12221002)。
文摘Shock wave caused by a sudden release of high-energy,such as explosion and blast,usually affects a significant range of areas.The utilization of a uniform fine mesh to capture sharp shock wave and to obtain precise results is inefficient in terms of computational resource.This is particularly evident when large-scale fluid field simulations are conducted with significant differences in computational domain size.In this work,a variable-domain-size adaptive mesh enlargement(vAME)method is developed based on the proposed adaptive mesh enlargement(AME)method for modeling multi-explosives explosion problems.The vAME method reduces the division of numerous empty areas or unnecessary computational domains by adaptively suspending enlargement operation in one or two directions,rather than in all directions as in AME method.A series of numerical tests via AME and vAME with varying nonintegral enlargement ratios and different mesh numbers are simulated to verify the efficiency and order of accuracy.An estimate of speedup ratio is analyzed for further efficiency comparison.Several large-scale near-ground explosion experiments with single/multiple explosives are performed to analyze the shock wave superposition formed by the incident wave,reflected wave,and Mach wave.Additionally,the vAME method is employed to validate the accuracy,as well as to investigate the performance of the fluid field and shock wave propagation,considering explosive quantities ranging from 1 to 5 while maintaining a constant total mass.The results show a satisfactory correlation between the overpressure versus time curves for experiments and numerical simulations.The vAME method yields a competitive efficiency,increasing the computational speed to 3.0 and approximately 120,000 times in comparison to AME and the fully fine mesh method,respectively.It indicates that the vAME method reduces the computational cost with minimal impact on the results for such large-scale high-energy release problems with significant differences in computational domain size.
文摘The paper presents a design method that ensures the ingenuity of the product form as well as the whole and exact expression of user’s needs. The key idea is to establish an automatic design system which can transform the user’s language needs into the product features in real-time. A rifle was taken as a research instance and soldiers were chosen as evaluation customers. The theory of fuzzy set and semantic difference are adopted to evaluate the relationship between user’s needs and product features as well as their alternatives. FAHP (fuzzy analytic hierarchy process) is utilized to judge the user’s satisfactory forms. This method can also be applied to other product form designs.
基金This project was supported by the National Natural Science Foundation of China (60474078)Science Foundation of High Education of Jiangsu of China (04KJD120016).
文摘The decentralized robust guaranteed cost control problem is studied for a class of interconnected singular large-scale systems with time-delay and norm-bounded time-invariant parameter uncertainty under a given quadratic cost performance function. The problem that is addressed in this study is to design a decentralized robust guaranteed cost state feedback controller such that the closed-loop system is not only regular, impulse-free and stable, but also guarantees an adequate level of performance for all admissible uncertainties. A sufficient condition for the existence of the decentralized robust guaranteed cost state feedback controllers is proposed in terms of a linear matrix inequality （LMI） via LMI approach. When this condition is feasible, the desired state feedback decentralized robust guaranteed cost controller gain matrices can be obtained. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed approach.
文摘A group of graphical models and mathematical models a re used to describe the methods of mass customization (MC). The relationships am ong the models and methods are shown in Fig.1. Fig.1 Relationships among optimization methods for MCThe methods for MC relate to both of product and process, also customized quanti ty and deepness. The methods for MC are integrated by the work in the paper, whi ch can help to understand and use MC better. The optimization and standardization of product is the key for MC. Increasing op timization breadth in product family can help to decrease the customization quan tity in every section of production process. Increasing optimization deepness in products family can help to move the CODCP backward in production process. At the same time, the optimization and standardization of product is the key to reduce cost of customized product. The optimization of the integration of pr oduct and process is the key to reduce lead time of customized product.
基金Project(61174132)supported by the National Natural Science Foundation of ChinaProject(2015zzts047)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(20130162110067)supported by the Research Fund for the Doctoral Program of Higher Education of China
文摘The temperature control of the large-scale vertical quench furnace is very difficult due to its huge volume and complex thermal exchanges. To meet the technical requirement of the quenching process, a temperature control system which integrates temperature calibration and temperature uniformity control is developed for the thermal treatment of aluminum alloy workpieces in the large-scale vertical quench furnace. To obtain the aluminum alloy workpiece temperature, an air heat transfer model is newly established to describe the temperature gradient distribution so that the immeasurable workpiece temperature can be calibrated from the available thermocouple temperature. To satisfy the uniformity control of the furnace temperature, a second order partial differential equation(PDE) is derived to describe the thermal dynamics inside the vertical quench furnace. Based on the PDE, a decoupling matrix is constructed to solve the coupling issue and decouple the heating process into multiple independent heating subsystems. Then, using the expert control rule to find a compromise of temperature rising time and overshoot during the quenching process. The developed temperature control system has been successfully applied to a 31 m large-scale vertical quench furnace, and the industrial running results show the significant improvement of the temperature uniformity, lower overshoot and shortened processing time.
基金Projects(50911130366, 50979030) supported by the National Natural Science Foundation of ChinaProject(2008BAB29B01) supported by the National Key Technology R&D Program of China
文摘Numerical analysis of the optimal supporting time and long-term stability index of the surrounding rocks in the underground plant of Xiangjiaba hydro-power station was carried out based on the rheological theory. Firstly,the mechanical parameters of each rock group were identified from the experimental data; secondly,the rheological calculation and analysis for the cavern in stepped excavation without supporting were made; finally,the optimal time for supporting at the characteristic point in a typical section was obtained while the creep rate and displacement after each excavation step has satisfied the criterion of the optimal supporting time. Excavation was repeated when the optimal time for supporting was identified,and the long-term stability creep time and the maximum creep deformation of the characteristic point were determined in accordance with the criterion of long-term stability index. It is shown that the optimal supporting time of the characteristic point in the underground plant of Xiangjiaba hydro-power station is 5-8 d,the long-term stability time of the typical section is 126 d,and the corresponding largest creep deformation is 24.30 mm. While the cavern is supported,the cavern deformation is significantly reduced and the stress states of the surrounding rock masses are remarkably improved.
基金supported by the National Natural Science Foundation of China(60574023)the Natural Science Foundation of Shandong Province(Z2005G01).
文摘An optimal tracking control （OTC） problem for linear time-delay large-scale systems affected by external persistent disturbances is investigated. Based on the internal model principle, a disturbance compensator is constructed. The system with persistent disturbances is transformed into an augmented system without persistent disturbances. The original OTC problem of linear time-delay system is transformed into a sequence of linear two- point boundary value （TPBV） problems by introducing a sensitivity parameter and expanding Maclaurin series around it. By solving an OTC law of the augmented system, the OTC law of the original system is obtained. A numerical simulation is provided to illustrate the effectiveness of the proposed method.
基金This project was supported by NSFC Project (60474047), (60334010) and GuangDong Province Natural Science Foundationof China(31406)and China Postdoctoral Science Foundation (20060390725).
文摘Decentralized robust stabilization problem of discrete-time fuzzy large-scale systems with parametric uncertainties is considered. This uncertain fuzzy large-scale system consists of N interconnected T-S fuzzy subsystems, and the parametric uncertainties are unknown but norm-bounded. Based on Lyapunov stability theory and decentralized control theory of large-scale system, the design schema of decentralized parallel distributed compensation （DPDC） fuzzy controllers to ensure the asymptotic stability of the whole fuzzy large-scale system is proposed. The existence conditions for these controllers take the forms of LMIs. Finally a numerical simulation example is given to show the utility of the method proposed.
基金Project(2011CB013601) supported by the National Basic Research Program of ChinaProject(51378258) supported by the National Natural Science Foundation of China
文摘Based on the explicit finite element(FE) method and platform of ABAQUS,considering both the inhomogeneity of soils and concave-convex fluctuation of topography,a large-scale refined two-dimensional(2D) FE nonlinear analytical model for Fuzhou Basin was established.The peak ground motion acceleration(PGA) and focusing effect with depth were analyzed.Meanwhile,the results by wave propagation of one-dimensional(1D) layered medium equivalent linearization method were added for contrast.The results show that:1) PGA at different depths are obviously amplified compared to the input ground motion,amplification effect of both funnel-shaped depression and upheaval areas(based on the shape of bedrock surface) present especially remarkable.The 2D results indicate that the PGA displays a non-monotonic decreasing with depth and a greater focusing effect of some particular layers,while the 1D results turn out that the PGA decreases with depth,except that PGA at few particular depth increases abruptly; 2) To the funnel-shaped depression areas,PGA amplification effect above 8 m depth shows relatively larger,to the upheaval areas,PGA amplification effect from 15 m to 25 m depth seems more significant.However,the regularities of the PGA amplification effect could hardly be found in the rest areas; 3) It appears a higher regression rate of PGA amplification coefficient with depth when under a smaller input motion; 4) The frequency spectral characteristic of input motion has noticeable effects on PGA amplification tendency.
基金supported by the National Natural Science Foundation of China(6057401160972164+1 种基金60904101)the Scientific Research Fund of Liaoning Provincial Education Department(2009A544)
文摘This paper focuses on the problem of non-fragile decentralized guaranteed cost control for uncertain neutral large-scale interconnected systems with time-varying delays in state,control input and interconnections.A novel scheme,viewing the interconnections with time-varying delays as effective information but not disturbances,is developed.Based on Lyapunov stability theory,using various techniques of decomposing and magnifying matrices,a design method of the non-fragile decentralized guaranteed cost controller for unperturbed neutral large-scale interconnected systems is proposed and the guaranteed cost is presented.The further results are derived for the uncertain case from the criterion of unperturbed neutral large-scale interconnected systems.Finally,an illustrative example shows that the results are significantly better than the existing results in the literatures.
基金financial support provided by the Iran University of Science and Technology
文摘The most common apparatus used to investigate the load-deformation parameters of homogeneous fine-grained soils is a Casagrande-type oedometer. A typical Casagrande oedometer cell has an internal diameter of 76 mm and a height of 19 mm.However, the dimensions of this kind of apparatus do not meet the requirements of some civil engineering applications like studying load-deformation characteristics of specimens with large-diameter particles such as granular materials or municipal solid waste materials. Therefore, it is decided to design and develop a large-scale oedometer with an internal diameter of 490 mm. The new apparatus provides the possibility to evaluate the load-deformation characteristics of soil specimens with different diameter to height ratios. The designed apparatus is able to measure the coefficient of lateral earth pressure at rest. The details and capabilities of the developed oedometer are provided and discussed. To study the performance and efficiency, a number of consolidation tests were performed on Firoozkoh No. 161 sand using the newly developed large scale oedometer made and also the 50 mm diameter Casagrande oedometer. Benchmark test results show that measured consolidation parameters by large scale oedometer are comparable to values measured by Casagrande type oedometer.
文摘Networked customization had gradually become one of t he import manufacturing and marketing patterns in the information age. Product d escription had an important effect on realizing networked customization. From th is point of view, this paper firstly analyzed four requirements of adaptability, stability, conciseness and definitude that product description methods for netw orked customization must satisfy. According to these requirements, the paper com mented on current methods of product description, pointing out their advantages and disadvantages. As none of current methods could satisfy the four requirement s simultaneously, they were not fully applicable to networked customization. The n a plug-in based product description method was brought forward and discussed in detail. In this method, product description for networked customization w as abstracted as three component parts of basic description, basic feature and c ustomization feature. These parts had different characteristics. Basic descripti on was applicable to all products types. Basic feature was stable as concerning specific product type. Variants of certain product type all possessed identi cal basic features. Customization features were variable. Different combinations of customization features would give birth to different product variants. Apply ing object-oriented method, three standard product description plug-ins could be got by encapsulating these component parts. As "basic feature" and "customiza tion feature" plug-in had similar structures, they could be further abstracted as "feature" plug-in. When describing a type of product, a "basic description" plug-in would be instantiated firstly. Then according to product’s specific ch aracteristics, necessary number of "basic feature" and "customization feature" p lug-ins would be instantiated and appended, such as "color", "material", etc. E ach "basic feature" plug-in related to an instantiated "feature value" plug-in , while each "customization feature" plug-in related to one or multiple instant iated "feature value" plug-ins. Finally, "associate" and "exclude" relation ship should be specified among associated "customization feature" plug-ins. Thr ough appending and combining various plug-ins, this method was capable of descr ibing any type of product while meeting the four requirements simultaneously. Th is paper also gave an example to clarify the application of plug-in based produ ct description method. This example firstly described a kind of customizable TV provided by certain company. Then it showed how to describe an individual co nfiguration of this customizable TV in XML. Furthermore, suppose a consumer want ed to search for relevant information of a TV with game function, this example explained how to utilize XML query language to benefit consumer’s searching for product information. From analysis, we could draw the conclusion that plug -in based product description method was superior to current description method s and fully adapted to networked customization environment.
文摘Based on introduction characteristics and classific at ion of Mass Customization (MC), the paper expounds foundations and design me thods of MC. The foundations of MC production are standardization, seriation and normality of production, guiding thought of Concurrent Engineering (CE), ap plication of CAD/CAM technology and etc. And design methods of MC products are d esign for product family, modular design, parameterization CAD, variant design, design for manufacturing (DFM) and design by customers. Design for product famil y is a method that first to design a basic form of the product, and then to with draw variant parameters to become a variable product model, makes a family or a series of product design at the same time. Modular design is that based on produ ct function analysis of different function or the same function but different sp ecification within a certain scope, divides and designs out a series of function modular, and through selection and combination of the modular can make up diffe rent products. Parameterization CAD is a CAD method that has function of dimensi on drive. Variant design is a method that under circumstance of keeping principl e constant and construction similar or likeness, properly adjusts part of constr uction and design parameters to adapt design demands. DFM demands the designer t o consider problems that will appear in manufacture in the stage of design, and to avoid them through optimal design. And design by customers is guiding custome rs to design within the scope of production capacity of enterprise and optional items that enterprise has designed to satisfy their requirements of form, functi on and price. Among them modular design, parameterization CAD and variant design are key technology of design methods of MC products. And design by customers is a main characteristic of design of customization product, and an effective sale means also.
文摘Mass Customization (MC) is one of the importance en te rprise produces modes in information age progressively. Mass Customization produ ct manufacturing is aimed at the objection of agile responding to customer deman d, market changing and market opportunities to combine with modern management te chnology and advanced manufacture technology, and to use the development model o f design for product family and technology concurrent. Therefore, in the environ ment of market continuing to change with a high speed, MC enterprise is required to raise its ability of controlling future market by improving its "agility of product manufacturing". So it is necessary to research about the question of agi lity evaluation of MC product manufacturing. Base on the characteristics of the Mass Customization (MC) product manufacturing and the requirement of the agile m anufacturing, this paper establish an MC product manufacturing Agility evaluatio n index system through studying MC enterprise’s organization management agility evaluation and MC products design agility evaluation and MC manufacture agility evaluation. Also, with Xi Dian Casting limited company as an example, the multi -grade fuzzy assessment method is used to evaluate its agility.
文摘In the view of the comparison of Mass Customization ( MC) with Mass Production and Customization Production, the objectives of MC are analyzed. It is pointed out that the core objectives of MC are to realize in dividuation customization, low cost, quick response to market demands. The modul arization theory is simply introduced. Based on the characteristics of modular ization, the mechanism of realizing MC with modularization is analyzed. The in dividuation customization can be realized with the different combinations of mod ules. The low cost can be realized with the scale economy and the category econo my of modules. The quick response can be realized with standard modules and its interfaces. So, the modularization is a kind of effective method in realizing MC . The modularization for MC is a systems engineering. With product modularized, production organization and management and manufacturing equipment will be chang ed. In addition, the paper also proposes a Mass Customization production model w hich is based on modularization. This Mass Customization production model is con sisted of modularization of product design, specialization of manufacturing, Vir tual Enterprises based on modularizing enterprises, and modularizing manufacturi ng equipment. The module design for MC, modularizing enterprises, and reconfigur able automation manufacturing equipment are discussed, and it is pointed out tha t they are the important supports for MC.
文摘Model Order Reduction (MOR) plays more and more imp or tant role in complex system simulation, design and control recently. For example , for the large-size space structures, VLSI and MEMS (Micro-ElectroMechanical Systems) etc., in order to shorten the development cost, increase the system co ntrolling accuracy and reduce the complexity of controllers, the reduced order model must be constructed. Even in Virtual Reality (VR), the simulation and d isplay must be in real-time, the model order must be reduced too. The recent advances of MOR research are overviewed in the article. The MOR theor y and methods may be classified as Singular Value decomposition (SVD) based, the Krylov subspace based and others. The merits and demerits of the different meth ods are analyzed, and the existed problems are pointed out. Moreover, the applic ation’s fields are overviewed, and the potential applications are forecaste d. After the existed problems analyzed, the future work is described. There are som e problems in the traditional methods such as SVD and Krylov subspace, they are that it’s difficult to (1)guarantee the stability of the original system, (2) b e adaptive to nonlinear system, and (3) control the modeling accuracy. The f uture works may be solving the above problems on the foundation of the tradition al methods, and applying other methods such as wavelet or signal compression.
文摘The developing status of world large-scale methanol production technology is analyzed and Linda's JW low-pressure methanol synthesis reactor with uniform temperature is described. JW serial reactors have been successfully introduced in and applied in Harbin Gasification Plant and the productivity has been increased by 50% and now nine sets of equipments are successfully running in Harbin Gasification Plant,Jiangsu Xinya, Shandong Kenli,Henan Zhongyuan, Handan Xinyangguang,' Shanxi Weihua and Inner Mongolia Tianye. Now it has manufacturing the reactors of 300,000 t/a for Liaoning Dahua. Some solutions for the structure problems of 1000 ～5000 t/d methanol synthesis rectors are put forward.
文摘The problem of partial stability is investigated for a class of continuous-time large-scale systems. Under assumption that the null solution of the isolated subsystems is stable, based on decomposition-aggregation methods and Lyapunov second method, some theorems concerning the globally partial asymptotic stability and globally partial exponential stability are obtained via utilizing the inequality analysis technique and comparison technique. Finally, an example is presented to illustrate the results.
文摘In this paper, we presented a method of using the l as er scanning triangulation for the non-contact 3D surface profile measurement of large-scale object. The characteristic of large-scale object non-contact mea surement is analyzed and the measuring method is proposed. Main factors influenc ing measurement precision such as image distortion and accurate designation of s peckle center are analyzed and methods of solving these problems are proposed. W e designed a combined filter by which the pulse noise and the Gaussian noise of speckle image can be eliminated efficiently. Using the characteristic of intensi ty distribution of laser speckle image we proposed a new approximating method th at could locate the center of laser speckle image at sub-pixel. The auxiliary v ariables are set to linearize the relationship between the image displacement an d the distance, the accurate values of laser triangulation system parameters cou ld be calibrated accurately and the measuring precision is increased remarkabl y. Using the above techniques we designed a measuring system based on laser sc anning triangulation. The results of the experiment show that these methods can raise the measuring precision of large-scale 3D surface profile effectively.
