Multi-objective constraint optimization design of rocket projectile self-ejection based on multi-population differential evolution algorithm

In view of the contradiction between reducing the pressure peak in low pressure chamber and increasing the exit velocity of self-ejection，the optimization design of self-ejection was carried out. A motor-low pressure coupled internal ballistic solution model of self-ejection was developed， physical experiments of two working conditions with four rockets were carried out. The multi-population differential evolution algorithm using differential strategy was proposed，“eliminate-complement operation” was adopted to deal with the constraints in the optimization process. A two-objective self-ejection constraint optimization model was established with the peak of pressure in low pressure chamber and the exit velocity considering the actual constraints of self-ejection，and this optimization model was calculated by the multi-population differential evolution algorithm. Results showed that，the Pareto front was of two segments with different slopes approximately. With the increase of pressure peak of low pressure chamber，the same increment of pressure led to a smaller increment of exit velocity. Twelve schemes were evenly selected in Pareto front and ranked by using technique for order preference by similarity to an ideal solution; the peak of pressure in low pressure chamber of the final optimized scheme of self-ejection decreased by 16.11%， the exit velocity of the final optimized scheme increased by 54.55%， and the performance of rocket projectile self-ejection had been improved. © 2023 BUAA Press. All rights reserved.