Study Of Robust Optimization Based On Six Sigma Theory

As the complexity of practical engineering problems, requirements about standards for product reliability and anti-interference ability are constantly improving. Based on the analysis of reliability research status at home and abroad and tolerance model, in view of the mechanical conventional optimization model and reliability probability optimization model are difficult to find an ideal steady solution, this paper introduces design ideas of 6 Sigma and combines with intelligent technology to study how to apply the 6 Sigma theory in mechanical parts optimization field. This essay studies systematically based on single objective robust strategies and robust strategy which has the characteristics of multi-objective, the main contents are as follows:(1) For mechanical products having some volatility problems in practical production, based on the analysis of deterministic optimization and reliability probability optimization model, this paper proposes a method of 6 Sigma reliability-based robust design which considering the influences of uncertain factors. Through mathematical quantizing the quality characteristics influence on fluctuation factors, this paper establishes robust optimization model accordingly and the concrete implementation process based on intelligent algorithm to solve the problem of single objective and multi-objective.(2) In view of the single objective robust optimization problem of mechanical parts, this paper respectively selects cylindrical spring and helical gear transmission system as a test case.① Optimizing an example of cylindrical spring is given to improve the parameters. First of all, making reliability analysis on general optimization of design variables combined with the corresponding variation and determining whether do robust design based on the analysis result or not. In view of General optimization solution have the characteristics of the constraints boundary, adding 6 Sigma robust constraints on the basis of conventional optimization model and getting the solution by using 6 Sigma robust model established by the ISIGHT simulation platform. By contrast to the former and the latter target and reliability of robust design to verify the feasibility of this method.②The purpose of the example of helical gear is to design parameters. The optimized target is to make the volume minimally, and the first step is building parametric general optimization model of the helical gear transmission system and adding 6 Sigma robust constraints, then we can use the ISIGHT instantiation model simulation platform to get the solution.(3) In view of multi-objective robust optimization problem of the mechanical parts, this paper improves transmission performance based on the single objective example of helical gear system calculation is the second optimization goal. Using MOPSO algorithm and NSGA-Ⅱ algorithm based on the thought of Pareto solution to search algorithm globally for multi-objective problem, and using EDM post-processing module of simulation software ISIGHT to get the Pareto robust optimal solution. Verifying the feasibility of the model based on lateral comparison of different algorithms results and longitudinal comparison of single objective and multi-objective.This paper applies the robust model on the basis of the theory of 6 Sigma to the single objective and multi-objective problem of mechanical parts, and the design results shows that 6 Sigma robust design can greatly improve the reliability of the spring and solve the problem about the lightweight and stability of helical gear transmission, the establishment of the model provides a certain method for the application of robust design and also provides a certain theoretical basis for applying the optimization theoretical solution to practice.