Layout Pattern Based Particle Swarm Optimization Algorithm For Layout Design Of Engine Compartment

Under supportting of National Nature Science Fundation of China(NO.50975039), this paper study a layout pattern based particle swarm optimization,and employ it for layout optimizing of engine compartment in special vehicle.A reasonable layout design of engine compartment,which takes an important role in special vehicle schematic design, is helpful for improving the performance of special vehicle, reducing it's mass and volume. But the problem of layout design of engine compartment belongs to NP-hard or NP-Complete problem. The main difficulty for solving this problem is that it is related to not only the combinatorial explosion in mathematics, but also the engineering complexity. Therefore, it is difficult to solve complex layout problem and is more difficult to satisfy the requirement of engineering application.To solve these problems,the main contributions of this dissertation are as follows:(1) Taking the layout design of engine compartment as engineering background, a layout pattern based particle swarm optimization(LPPSO) is presented from the perspective of layout pattern transformation,and is employed to solve the problem of layout design of engine compartment. During the initial stage and optimizing process of LPPSO, some non-isomorphic individuals are constructed,which are added into current population of PSO to replace bad individuals. In this way,the new population is created for next cycle of arithmetic.In this study,the non-isomorphic layout pattern is generated by the quasi-boundary line approach based on complete incidence graph, in the purpose of avoiding prematurely convergence and improving the arithmetic's efficiency. Two examples that originate from layout design of satellite module and printed circuit board(PCB) show that LPPSO is feasible and effective.And this paper carry out a research on using LPPSO to optimize the layout scheme of compartment in special vehicle.(2) This dissertation also presents several key techniques of developing CAD software in the purpose of solving the practical problem which is faced in using LPPSO to optimize the layout scheme of compartment in special vehicle. These key techniques include the overall design of CAD software, the identification of objects in assembly, management of mass property of homogenize and un-homogenize parts, and the calculation of centroid of objects. From the view of engineering, the software was developed, and have been used by relative engineers.