RESEARCH ON THE GENERALIZED MODULAR DESIGN METHOD WITH FLEXIBLE MODULES OF PRODUCT STRUCTURES

A new generalized modular design (GMD) method is proposed based on design practice of frame structure of hydraulic press machines. By building a series of flexible modules (FMs), design knowledge and structure features are integrated into parametric models. Then, parametric design and variational analysis methods for GMD are presented according to user defined design objectives and customized product characteristics. A FM-centered GMD system is developed and successfully used in the rapid design of relevant products.     

Configurable product design considering the transition of multi-hierarchical models

The current research of configurable product design mainly focuses on how to convert a predefined set of components into a valid set of product structures. With the scale and complexity of configurable products increasing, the interdependencies between customer demands and product structures grow up as well. The result is that existing product structures fails to satisfy the individual customer requirements and hence product variants are needed. This paper is aimed to build a bridge between customer demands and product structures in order to make demand-driven fast response design feasible. First of all, multi-hierarchical models of configurable product design are established with customer demand model, technical requirement model and product structure model. Then, the transition of multi-hierarchical models among customer demand model, technical requirement model and product structure model is solved with fuzzy analytic hierarchy process (FAHP) and the algorithm of multi-level matching. Finally, optimal structure according to the customer demands is obtained with the calculation of Euclidean distance and similarity of some cases. In practice, the configuration design of a clamping unit of injection molding machine successfully performs an optimal search strategy for the product variants with reasonable satisfaction to individual customer demands. The proposed method can automatically generate a configuration design with better alternatives for each product structures, and shorten the time of finding the configuration of a product.     

TECHNOLOGY AND APPLICATION OF PRODUCT EVOLUTIONARY DESIGN BASED ON CONFIGURATION IN MASS CUSTOMIZATION MODE

Product customization has been recognized as an effective means to implement mass cus-tomization (MC). A new theory and method for MC-oriented evolutionary design of configuration product is presented based on the study of developing law of evolutionary design in integrated envi-ronment, which focuses on the innovation and reuse properties of configuration product. The key technologies for general requirement modeling in quick response to customer requirement, multi-level stepwise configuration optimization driven by customer requirement and evolutionary deduction of product variable structure based on configuration association are thoroughly investigated. The suc-cessful application of the presented method in the development of real-life products demonstrates its utility, flexibility and robusticity.     

Reconfigurable modeling technology of similar-structure products configuration design

The product configuration modeling is a key technology to realize configuration design.Most of the researches were mainly conducted focusing on how to establish a product configuration model,but were short of the consideration about the application scope and dynamic change features.In this paper,the reconfigurable modeling technology of similar-structure products configuration design is studied to enhance the generality and diversity of product configuration models,and to facilitate the dynamic upgrade of configuration models.The configuration components of products with similar structures are divided into sharable configuration components,essential configuration components and optional configuration components,so the construction of reconfigurable model of configuration design can be converted into the set operation of configuration components.The horizontal adjusting reconstruction of configuration model is carried out through the adding,replacing and deleting of configuration components,the vertical adjusting reconstruction of configuration model is carried out through the parametric deformation of configuration components,and the variable topological configuration model reconstruction can be realized through the transformation of partial structure of configuration components.Finally,NC machine products are used as an example to analyze and verify the reconfigurable modeling technology of products with similar structures.The speed of NC machine configuration design is found to be improved,and the number of NC machine configuration design models is decreased.And the reconfigurable design system of NC machine products is developed.The proposed modeling technology provides references for the processes,methods and steps of model reconstruction.     

A task-oriented modular and agent-based collaborative design mechanism for distributed product development

The rapid expansion of enterprises makes product collaborative design （PCD） a critical issue under the distributed heterogeneous environment, but as the collaborative task of large-scale network becomes more complicated, neither unified task decomposition and allocation methodology nor Agent-based network management platform can satisfy the increasing demands. In this paper, to meet requirements of PCD for distributed product development, a collaborative design mechanism based on the thought of modularity and the Agent technology is presented. First, the top-down 4-tier process model based on task-oriented modular and Agent is constructed for PCD after analyzing the mapping relationships between requirements and functions in the collaborative design. Second, on basis of sub-task decomposition for PCD based on a mixed method, the mathematic model of task-oriented modular based on multi-objective optimization is established to maximize the module cohesion degree and minimize the module coupling degree, while considering the module executable degree as a restriction. The mathematic model is optimized and simulated by the modified PSO, and the decomposed modules are obtained. Finally, the Agent structure model for collaborative design is put forward, and the optimism matching Agents are selected by using similarity algorithm to implement different task-modules by the integrated reasoning and decision-making mechanism with the behavioral model of collaborative design Agents. With the results of experimental studies for automobile collaborative design, the feasibility and efficiency of this methodology of task-oriented modular and Agent-based collaborative design in the distributed heterogeneous environment are verified. On this basis, an integrative automobile collaborative R＆D platform is developed. This research provides an effective platform for automobile manufacturing enterprises to achieve PCD, and helps to promote product numeralization collaborative R＆D and management development.     

LXI instrument development platform based on an open embedded operating system

This paper introduces the architecture and components of LXI instrument development platform based on an open embedded operating system,which is a modular and configurable platform.The platform is a total solution to develop LXI instrument modules and systems.On the other hand,it also supports other types of instrument development.This is a generic and efficient platform.At the end,this paper addresses the technical tends, challenges,and recormnends solutions.     

HYBRID CONTROL OF HYDRAULIC PRESS MACHINE BASED ON ROBUST CONTROL

A robust control algorithm is proposed to focus on the non-linearity and variables of the hydraulic press machine with the proportional vatve. The proposed robust controller does not need to design stable compensator in advance, which is simple in design and has large scope of uncertainty applications. The feedback gains of the proposed robust controller are small, so it is easily implemented in engineering applications. The theoretical and experimental research on the position and speed control of the hydraulic press machine is carried out. The control requirements of the hydraulic press machine during the working process are met in the position and speed at the same time. Experimental results show that the proposed controller has better robustness subject to load variables and adaptability of parameter variations of the hydraulic press machine with the proportional valve.     

Product modular design incorporating preventive maintenance issues

Traditional modular design methods lead to product maintenance problems, because the module form of a system is created according to either the function requirements or the manufacturing considerations. For solving these problems, a new modular design method is proposed with the considerations of not only the traditional function related attributes, but also the maintenance related ones. First, modularity parameters and modularity scenarios for product modularity are defined. Then the reliability and economic assessment models of product modularity strategies are formulated with the introduction of the effective working age of modules. A mathematical model used to evaluate the difference among the modules of the product so that the optimal module of the product can be established. After that, a multi-objective optimization problem based on metrics for preventive maintenance interval different degrees and preventive maintenance economics is formulated for modular optimization. Multi-objective GA is utilized to rapidly approximate the Pareto set of optimal modularity strategy trade-offs between preventive maintenance cost and preventive maintenance interval difference degree. Finally, a coordinate CNC boring machine is adopted to depict the process of product modularity. In addition, two factorial design experiments based on the modularity parameters are constructed and analyzed. These experiments investigate the impacts of these parameters on the optimal modularity strategies and the structure of module. The research proposes a new modular design method, which may help to improve the maintainability of product in modular design.     

Reciprocal screw theory based singularity analysis of a novel 3-DOF parallel manipulator

Singularity analysis is an essential issue for the development and application of parallel manipulators.Most of the existing researches focus on the singularity of parallel manipulators are carried out based on the study of Jacobian matrices.A 3-DOF parallel manipulator with symmetrical structure is presented.The novel parallel manipulator employs only revolute joints and consists of four closed-loop subchains connecting to both base and platform via revolute joints.The closed-loop subchain in each chain-leg is a spherical 6R linkage.The motion characteristics of the output link in the spherical 6R linkage with symmetrical structure are analyzed based on the interrelationships between screw systems.The constraints that are exerted on the platform by each chain-leg are investigated applying the concept of generalized kinematic pair in terms of equivalent screw system.Considering the geometric characteristics of the parallel manipulator,the singularity criteria of the parallel manipulator corresponding to different configurations are revealed based on the dependency of screw system and line geometry.The existing conditions of certain configuration that a singularity must occur are determined.This paper presents a new way of singularity analysis based on disposition of constraint forces on the geometrically identified constraint plane and the proposed approach is capable of avoiding the complexity in solving the Jacobian matrices.     

Impedance analysis of forging process and strategy study on compliance for forging manipulator

In the field of heavy forging, there are numerous researches on deformation rule in forging process by FEM simulation, however, not many scholars take the equipment constraint and the mutual reaction load between the forging manipulator clamp and the forging blank into account, which will impact on safety of manipulator body and quality of forging blank. This paper presents an impedance model to describe the load and formulates compliance strategies correspondingly to reduce the mutual reaction load for forging manipulator. Firstly, an FEM model of forging process is built. Meanwhile, the clamp of forging manipulator is added to the model as movement constraint and interaction part between the manipulator and the forming process. Secondly, a typical forging process is simulated by changing the movement constraint, and then an impedance model is established to describe the relationship between the load and movement constraint. Finally, two kinds of compliance strategies are formulated according to the impedance model, one is called free compliance, and the other is initiative/passive compliance. The simulation results show that compliance strategies reduce the load amounting to 5 000 kN in z direction between the manipulator clamp and the forging blank obviously, which may lead to serious accidents, such as the capsizing of forging manipulator, the fracture of manipulator clamp, and so on. The proposed research simulates the more real forging process, gets the initiative/passive compliance strategy which is more simple and suitable to the real producing and better for forming a forging process planning and control system in the modern production, and improves the quality and efficiency of heavy forging.     

Product cooperative disassembly sequence planning based on branch-and-bound algorithm

This paper focuses on the cooperative disassembly sequence planning (CDSP) problem which is essential to disassembly a large and complex product in practice. A disassembly hybrid graph model (DHGM) is constructed to describe the mating contact and noncontact priority relationships among constituting product components. Thus, the disassemblability constraint expression can be deduced from it by reasoning. The CDSP is different from the disassembly sequence planning except for they are NP-complete. Therefore, a novel method is presented to generate cooperative disassembly hierarchical tree (CDHT) from the DHGM based on branch-and-bound algorithm in which two user-defined variables are introduced to control the size of the CDHT .The optimal solutions with a minimal disassembly time are derived according to the objection function. Finally, an example illustrates the proposed method.     

基于产品族的产品结构建模及配置研究

根据产品族和GBOM可配置产品的特点,构造了一个基于产品族的可配置产品结构模型,分析了配置模块的构成、模块及其属性之间的约束关系。在配置过程中,定义了模块配置参数和配置规则,并举例说明参数化配置的实现过程。说明了各种BOM的产生、结构和信息变化及其管理。最后给出了该产品结构模型及产品配置的应用实例。     

拆卸与或图模型中的可拆卸性筛子

面向拆卸的设计是机电产品绿色制造系统中的重要组成部分，拆卸与或图是进行面向拆卸的设计时开展拆卸过程规划所需的一种模型。系统研究了构造拆卸与或图模型过程中的可拆卸性筛子，提出了可拆卸性筛子的模块划分和筛选流程。对零件之间拆卸运动干涉的判定，运用了包容盒检测、穿刺检测和步进静态干涉检测相结合的方法。开发了基于SolidWorks的可拆卸性筛选系统，对开发过程中遇到的难点进行了详细阐述。本文的研究工作保证了拆卸与或图模型、从而拆卸过程规划结果的正确性，同时对面向装配的设计中的装配干涉判定也具有一定的应用价值。     

Configuration-oriented product modelling and knowledge management for made-to-order manufacturing enterprises

In made-to-order (MTO) manufacturing enterprises (ME), product architectures are usually modularised and components standardised. Product configuration is a key technology for order realisation in MTO–ME and is a typical knowledge-based application. Through a configuration process, product modules or components are selected and assembled according to customer requirements. Product configuration relates to a great deal of knowledge that represents complexity relations among components or modules, such as configuration rules and assembly constraints. Traditional product modelling techniques are focused mainly on physical product modelling and geometric representation, which makes them insufficient to help in the product configuration process. This paper discusses configuration-oriented product modelling and knowledge management for MTO–ME. A general process of product configuration modelling is proposed. The configuration model represents a product family from which a specific configuration solution or product variant can be derived. Actually, configuration modelling is a process which captures and represents product knowledge. In this paper, product knowledge is organised and managed through a knowledge component (KCOM) that includes configuration rules and constraints. A KCOM-based product knowledge representation model is presented. Finally, a PDM system is extended to support product modelling and knowledge management for MTO configurable products .     

面向拆卸与回收的设计指南

环境恶化、资源贫乏和大量废弃物难以处理的矛盾使得面向拆卸与回收的设计成为近年来设计制造领域研究的一个热点。拆卸与回收是产品生命周期中的关键环节 ,因而产品的可拆卸性和可回收性是面向环境设计需要考虑的重要内容。本文通过对影响拆卸和回收的各种因素的分析 ,形成了一系列指导设计过程的设计指南     

基于布局模型的液压机大规模定制设计

为实现液压机产品的大规模定制快速响应设计,提出了一种基于布局模型的产品设计方法。通过构建液压机的产品功能需求模型、运动功能模型和模块结构模型之间的映射,将得到的布局结构实例化,采用有限元和变量化方法进行布局结构的分析和优化,从而得到最优布局模型。分析得到的所有布局模型将作为产品平台的一部分加以存储,以支持产品的大规模定制设计。论述了液压机产品布局模型的拓扑结构和约束信息表达方法。最后给出了基于布局的大规模定制产品的配置和变型设计过程,该过程显示,布局模型的研究与应用可明显提高液压机类机械产品的设计效率。另外,对产品布局模型在大规模定制产品平台开发过程中进行了分析,完善和补充了大规模定制产品平台体系。     

基于知识工程的液压系统配置设计

为了提高液压系统的设计质量和效率,以知识工程理念为基础,提出了液压原型单元和液压配置单元的概念,给出了它们的知识表达,并建立了相应的IDEF1x信息模型;进而设计了液压系统两阶段配置求解算法:第一阶段根据设计要求和主要参数计算结果,为液压系统原理图中的每个液压原型单元选配出配置单元;第二阶段以价值系数、质量水平和可靠度为优化目标,建立基于遗传算法的液压系统配置求解体系并进行求解。该算法收敛性好,实用性强,能有效地解决液压系统配置组合爆炸问题。最后,以折弯机液压系统配置设计为实例,验证了所述方法的可行性和有效性。     

基于分形理论的产品配置设计研究

在分析了分形理论与产品配置设计之间关系的基础上,提出将分形理论应用于产品配置设计的构想,构建了一种基于分形思想的产品配置元模型,设计了基于分形思想的产品族基本结构.根据可配置元模型和基本结构,设计了一种基于分形迭代的产品配置求解方法,并给出了应用实例.     

开式变量泵控油压机系统控制特性研究

为解决大功率自由锻造油压机高能耗的问题,设计了一种开式变量泵控油压机系统。采用ADAMS和AMESim建立了开式变量泵控油压机系统联合仿真平台,对其常锻工况和快锻工况的控制特性进行了仿真研究。基于600kN锻造油压机实验平台,对其常锻工况和快锻工况的控制特性进行了验证,并将验证结果与仿真结果进行了对比。研究结果表明:开式变量泵控油压机系统能够满足技术要求,即常锻时操控性好,卸压无冲击,运行平稳;快锻（锻造频次80次/min）时,位置控制精度小于1mm。     

锻造液压机生产过程能耗分布规律研究

针对锻造液压机能耗高、能量利用率低的问题,研究其正常生产工况下的能耗分布规律。以16 MN 阀控锻造液压机为研究对象,利用AMESim建立其仿真模型,并通过位移压力仿真曲线验证仿真模型的正确性,基于该仿真模型对锻造液压机一个工作循环中的能量利用情况进行仿真研究,获得能耗分布规律。仿真结果表明:在阀控锻造液压机的正常生产工况下,负载有用功在整个能耗中占比小于10%,溢流能耗和节流能耗在系统中造成了巨大的能量损失,通过改进液压系统设计、控制液压系统阀的开启规律可以提高压机能量利用率。