Abstract: In order to obtain the optimal design of a differential piston warm gas self-pressurization system for the liquid attitude and divert propulsion system， an approach for design optimization through genetic algorithm is discussed. The system includes the solid start cartridge， pressure amplified tank with liquid monopropellant， liquid regulator， gas generator， pipes. The multi-objective constrained optimization is aimed at the system total mass and starting time minimization with given requirements， constraints and design assumptions. Evaluation modules are developed to estimate the system total mass， the axial dimension， the radial dimension and the system performance parameters. The weighted sum method and penalty function method as well as the genetic algorithm are utilized to solve the multi-objective constrained optimization. According to the Pareto-frontier solutions， the optimized results can be obtained， whereas the weighted factor of the system total mass varies within ［0.4， 1.0］. The single-objective optimizations are executed to obtain the optimal value of each system parameter， the system total mass， the starting time， the centroid drift， the axial dimension and the radial dimension can be respectively decreased 23.17%， 34.40%， 84.10%， 62.28% and 4.14%， and the pressurization efficiency can be increased 0.42%. The design variables effects on the system parameters are also investigated. These parameters are mainly affected by the gas cavity initial volume， the liquid cavity diameter of the pressure amplified tank and the solid propellant mass of the start cartridge.

Key words: Differential piston；Warm gas self-pressurization system；Liquid attitude and divert propulsion system；Multi-objective optimization；Genetic algorithm

摘要： 为了进行应用于液体姿轨控动力系统的差动活塞式热气自增压系统优化设计，研究了一种基于遗传算法的优化设计方法。该系统由起动药盒、压力放大贮箱、流量调节器、燃气发生器和管道等组成。文中提出了在给定要求、约束和假设条件下进行系统总质量和起动时间的有约束多目标优化任务；建立了系统总质量、轴向尺寸、径向尺寸和系统性能参数的计算模型；采用归一加权法、惩罚函数法以及遗传算法求解了有约束多目标优化问题。根据帕累托前沿解，系统总质量的加权因子在［0.4，1.0］内变化时，可以得到优化结果。为了得到系统参数作为单目标的优化结果，本文进行了系统单目标优化，系统总质量、起动时间、质心漂移、轴向尺寸和径向尺寸各自作为优化目标可分别降低23.17％，34.40％，84.10％，62.28％和4.14％，增压效率可提高0.42％。分析了设计变量对系统参数的影响，结果表明压力放大贮箱气体腔初始体积、液体腔直径和起动药盒固体推进剂质量是影响系统参数的主要设计变量。

关键词: 差动活塞；热气自增压系统；液体姿轨控动力系统；多目标优化；遗传算法