A Multi-objective Optimization Based Safety Requirement Assignment for Aircraft Systems by Using NSGA-II

Abstract

The assignment of safety requirements is an important task in the design and evaluation of complex aircraft systems. The safety assignment of development assurance level and failure probability for the items/functions can minimize the possibility of errors in the development process. The development assurance levels of the items/functions consisting of the system are taken as decision variables, the assignment principle of development assurance levels and the probability requirement of the top failure conditions are taken as constraints, and the minimization of the development cost and system weight is taken as the optimizing objective, the multi-objective safety requirement assignment model was established. Taking the vector composed of the development assurance levels of all items/functions as the individual chromosome, a method of solving the model based on non-dominated sorting genetic algorithm (NSGA-II) is proposed. Finally, an application instance is given based on a certain fly-by-wire system. The results show that the proposed method can reduce the dependence on designers' experiences or skills effectively.