6σ Robust Optimization Design for Wedge Ring Connection Structure of Torpedo

The main problems in optimization design include unsuitable initial value selection,circumstance interferences and random fluctuation of variables,which make the quality of product unstable.Robust design is a useful way to make quality of product insensitive to these factors.Combing the 6σ concept with sequential quadratic programming,this paper established a 6σ robust optimization design method,which not only searches the optimum results for the design object,but also improves the robustness and reliability of a product.Taking the design of the wedge ring connection structure of torpedo as an example,the presented method was used to obtain better optimum solution than the one with the deterministic optimization method.