Optimization Design For Cost Of Solid Rocket Motors

With the end of cold-war and the intension of competition of aerospace launch market, people hammer at constantly the performance of products and meanwhile they more concern decreasing the cost. Based on the concept of Design for Cost (DFC) proposed by NASA, the paper explores the methods to realize DFC from both quantitative and qualitative approaches and applies them into the process of concept design of Solid Rocket Motors.Key techniques and main measures that apply Genetic Algorithm (GA) to multiobjective search are studied. Based on the comparison of various Multiobjective Optimization GA(MOGA), a new algorithm called Improved Pareto GA(IPGA) that combines the NSGA-II and local search algorithm is presented. At first, it uses the NSGA- II for obtaining the approximate Pareto optimization solutions. Then, local search is run with previous each solution to find a better solution using the mode search algorithm. The convergence of the new algorithm is better then that of NSGA- II through examination of a testing function.The optimization design of DFC is expounded and the concept and method of multiobjective optimization are used to the upper stage solid rocket motor (CPKM) of a kind of launching vehicle. The paper studies the main explaining parameters that influence manufacturing cost of parts and gets parameter-cost models. Using the IPGA and setting the terminal speed increment of the upper stage and the manufacture cost of CPKM as objective functions, the rocket motor are processed dual-objective optimization design that has six design parameters. Adopting the APMOC and carbon fiber materials of shell, the paper gets the Pareto optimal sets that uniform distribution in objective space and the optimal solution of performance. Using illustration method, the trade-off solution is obtained that the distance between the Pareto optimal sets and ideal point is shortest. The analysis shows that the trade-off solution is more rational than optimal solution of performance.The influence of design parameters on performance and cost around CPKM's trade-off solution is studied. A method of Quality Function Deployment (QFD) is used to research on DFC qualitatively. Adopting fuzzy theory to improve the traditional QFD and using two QFD matrixes to transfer the demands of consumers about CPKM into the priority of design's characteristics and component's characteristics, the DFC isdirectly realized. According to satisfactory range of fuzzy parameter to compute the membership function, a fuzzy synthesis assessment method is applied to judge system design level of 12 design schemes of CPKM and the optimal scheme is obtained.Based on the analysis of the influence of GA operators on population diversity, this paper studies parameter control of GA and proposes a self-adaptive mutation probability. It can automatically regulate the mutation probabilities according to the population diversity at primitive stage and adopt different mutation probabilities at different stages. The results show that it is better than the fix and adaptive mutation probabilities.A GA to resolve process route optimization of solid rocket motor shell is studied. This paper proposes the array chain chromosome coding and the Adaptive GA (AGA) that combines the self-adaptive mutation probability and simulation anneal punishment function. The emulation computation shows its availability. And taking the manufacturing process of the solid rocket motor shell for example, value of process route as objective and cost of process route as constraint, an optimization process is obtained using AGA.At last, a method that combines Gray Model GM (0,N) and Adaptive Neural Fuzzy Inference System (ANFIS) to set up parameter cost model is proposed. The method takes advantage of Gray Model acceptable for modeling of small samples to produce additional trained samples of network in the region of poor information and then uses ANFIS to train network again. By means of the data of missile's performance and cost as example, the method can effectually mode...