Research On Model Control And Management For Computer Supporting Collaborative Design Process Of Mechanical Products

With the further development of economic globalization process, as one ofpillar industries in our national economy, the machine-building industry willface even more fierce market competition. The core of competition amongmachine-building industries lies on their design ability for mechanical products.Presently, China has been a major country but not a strong power among globalmanufacturing. The main reason is that most products in our country are lack ofinnovative design ability, are short of own intellectual property rights as well aswith a low market competition. Hence, it is one of the most pressing tasks tobuild a net products design pattern fitting for the requirement of uses andmarkets and responding fast, which is also a key for manufacture industry to getout of morass, gain market and have the initiative of competition.Manufacture products collaborative design is an advanced design patternbased on sharing distributive design resource; meanwhile, it adopts moderntheory to design products. It also means a process of completing design tasks toa complex mechanical products design task by multi-subject groupscooperatively and collaboratively by means of sharing design resourceremotedly under the environment of distributed network. The mechanicalproducts collaborative process has such characteristics as concurrent andmulti-agent design tasks and dynamic and uncertain design process. How todynamically model, control and manage it effectively has been one of coreproblems to be studied in collaborative design domain. This thesis mainlyreseaches on the problems of model, control and management to mechanicalproducts collaborative design process and its work and innovation include asfollows:1. The problems of dynamic modeling and decision-making controlling inmechanical products collaborative design process are studie. Mechanicalproducts collaborative design process has the characteristics of groupcooperating, dynamically distributing, concurrently executing and sharingcollaborating. At first, mechanical products design business flow model isanalyzed and built. Then, a metamodel of mechanical products basic design unit is constructed based on OPN theory. Meanwhile, control net model of designprocess is established by introducing decision-making information place anddecision-making transition. Finally, a dynamic model for mechanical productscollaborative design based on metamodel invoking is proposed. This modelachieves dynamic description of mechanical products collaborative designprocess by banding input/output interface of metamodel invoking withdecision-making transition of process control net model. At the same time, acontrolling decision-making strategy and algorithm of mechanical productscollaborative design process based on fuzzy inference rules is presented byadopting fuzzy inference rules in fuzzy Petri net to solve the problem ofdecision-making controlling in mechanical products collaborative designprocess.2. The problems of temporal constraint inference and consistency analysisof mechanical products collaborative design process are studied. A temporalconstraint TCPN model fitting for mechanical products collaborative designprocess is proposed by introducting temporal constraint Petri net and linearitylogic expression theory to solve the problems of time constraint relation andtime computing inference for collaborative design process. Synchronously,temporal constraint relation expression, temporal constraint controlling structureand temporal constraint calculation relationship are given. For the temporalconstraint types with different controlling structure, their temporal constraintspring rules and inference rules are also given.3. The problem of resource constraint scheduling of mechanical productscollaborative design process are studied. In order to solve resource constraintconflict caused by limited design resource and concurrent design activity, theproblem of design rescource constraint conflict is turned into the problem oftemporal constraint scheduling for users occuping resource. As a result, aresource constraint model of collaborative design process based on TCPN isproposed. Meanwhile, the resource constraint scheduling rules and algorithm ofproducts collaborative design process are presented by studyingweak-scheduling of asynchronous design activity transition andstrong-scheduling of synchronous design activity transition. 4. The problems fuzzy comprehensive evaluation and decision-making arestudied. A fuzzy and comprehensive model and its algorithm fitting mechanicaloriginal design schemes and system general design scheme productscollaborative design process with multi-objectives and multi-layers arepresented to solve the problem of comprehensive evaluation anddecision-making for the stages of original design schemes and system generaldesign scheme. To the layer of evaluating initial schemes, the evaluation strategyof key objective factor is adopted, which are evaluated by calculating the vectormatrix of membership degree between evaluated characteristic values ofmultiple initial schemes and the evaluation indices. To the layer of evaluatingsystem general design scheme, the vector matrix of membership degree betweenevaluation characteristic values of experts and evaluation rank is calculated bythe comprehensive weighted strategy for multi-objective and the algorithm ofgeneralized Minkowski distance.5. The problem of dynamic access control to mechanical productscollaborative design process management system is studied. A dynamic accesscontrol model of CSCD-TRBAC fitting collaborative design processmanagement system is proposed based on extending and integrating RBACmodel and TBAC model to solve the collaborative design process controlproblem with the characteristics of cycle temporal constraint, access numberslimitation and design process dynamically variety. In this model, the accessauthorization status varying and authority restraining are controlled by the statustransition and constraint dependence relationship of design tasks.Simultaneously, the problems of authority access time limitation and transactionintegration constraint are solved by setting the limits to authority activatingcycle time and the limits to authority access numbers. Finally, the authorityallocation strategy and authority activiting mechanism of task-based are given.6. The above theories are synthesized and the collaborative design processmanagement of transmission gear box is taken as prototype. Its functionstructure and engine principle are analyzed firstly and its design processbusiness flow model is presented. Then five subsystems of the whole systemsuch as project task management, design resource management, products data management, process modeling and analyzing, and access control managementare designed detailly based on the detail analysis to the and design processmodel. Finally, the conceptual model and physical model of system database arebuilt. Meanwhile, the detail design schemes of the system are given.