| Engines,nuclear reaction pumps and other complex mechantronic products have a large number of components and pipelines,which are responsible for the operation and control of products by transporting fuel,hydraulic oil,lubricating fluid and so on.These staggered and complex pipelines have straight,curved,branching forms.For efficiency and stablity of complex mechantronic products,piping system should be laid reasonably and optimally.Moreover,pipe routing has a decisive effect on development speed and production cycle of complex mechantronic products.Piping routing should consider not only pipeline placement,but also pipeline manufacturing,flow loss and other professional matters,which makes it difficult to ensure the efficiency and effectiveness of pipe routing.With the demand of miniaturization,precision and green of complex mechantronic products,pipe routing becomes more and more difficult.Although there are some optimization methods of pipe routing,the optimization method of pipe routing for complex mechantronic products should be further studied.In this thesis,in order to improve the efficiency and quality of pipe routing,engineering rules and the optimization methods of pipe routing for complex mechantronic products are systematically studied.The main contents of this thesis are listed as follows:(1)Engineering rules of pipeline layout for complex mechantronic products are systematically analyzed.The implementation methods of all kinds of engineering rules are determined based on their classificiations.The hierarchical evaluation system is established for multi-direction evaluation of layout results of different pipelines.(2)A multi-pipe routing optimization method based on classified ant colony algorithm is proposed.Considering the layout space and pipeline characteristics,the layout space modeling based on the twice mesh division is created.Based on search methods of ant colony and layout demands of pipelines,ant colony is classified according to different-steps search and different-node selection mechanisms to balance the search accuracy and search efficiency.Positive and negative feedback mechanism of dynamic pheromone updating based on rank and multi-directions heuristic information are set.By the collaborative factor and the collaborative objective function,the multi-group parallel evolution mechanism is constructed to get multi-pipeline collaborative optimization,which can satisfy the multiple engineering rules.(3)An optimization method for free curved pipelines is proposed.Considering characteristics of the space layout and adjustment demands of free curved pipelines,adaptive octree modeling of the layout space is constructed.Ant colony algorithm is modified to hierarchically search neighbor nodes and get control points of cubic B-spline curve to construct the axis of free curve pipelines.By curvature change of the curve,bad points in control points are found and the axis is adjusted piecewise to fair the axis and decrease the flow loss.The hierarchical heuristic information and twice collision detection are set for the efficiency of the algorithm.(4)An optimization method for branch pipe routing is proposed.Based on the knowledge of graph theory,space connection graphs are studied.The shortest path node rule is proposed.A new 3D connection graph is constructed.The potential value is set according to the node types for satisfying engineering rules.Considering the requirements of the branch points and search characteristic of ant colony,ant grouping rule and parallel search mechanism are set.The obstacle-avoiding minimum Steiner tree with obstacles is obtained by iteration and the optimal branch points and path are obtained.(5)A pipe routing module for complex mechantronic products is developed.Based on UG/NX software platform,a 3D pipe layout optimization design system is developed by UG/Open,C++ and Matlab. |
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