| As the core part in the aircraft design, designing overall parameters is running throughthe whole process, and is an important factor that determines whether the model developmenttask could be implemented smoothly. The optimization of overall parameters, especially thetrajectory parameters, has very important significance for improving model performance,ensuring task feasibility, guiding subsequent design and so on. However, aircraft overallparameters are constrained by various disciplines and factors, and the coupling amongparameters is strong. Consequently, the optimization of the overall parameters is so difficultthat turns into the research focus at home and abroad.This paper conducted a study on the optimization of aircraft overall parameters andtrajectory parameters. Specific contents as follows:(1) On the basis of summarizing the trajectory optimization techniques at here andabroad, the overview of common algorithms’ principle and application was given. And then,each relative merits and growing trend was analyzed in detail. More applied new methods andvarious trajectory optimization software products in recent years were introduced at last.(2) To facilitate the subsequent analysis, this paper defined the usual coordinates andtransforming relationship. The specific calculating process aiming at the aerodynamic forcesand torques were provided. On the basis of anterior contents and simulating the USSA76atmosphere model, the dynamical model for vehicle movement was deduced systematically.(3) To the overall parameters optimization, the vehicle overall parameters optimizationmethod based on complex method and its solution procedure was proposed. On thebackground of small cruise missile, this paper deduced the takeoff mass estimation formula.Considering the various factual constraints and taking the minimal takeoff mass as the goal,the overall parameters optimization based on cruise missile was analyzed. Calculation resultsshow that the proposed method is feasible and efficient, and also provide the theory evidencesand technology supports.(4) To the trajectory optimization, the vehicle trajectory optimization method based onthe combination of direct shooting method and complex method was proposed. On thebackground of reentry vehicle, the influence of the initial trajectory parameters (velocity, height and path angle) on the trajectory shape is analyzed. Considering the dynamical model,aerodynamic model and optimization model, and taking the farthest range as the goal, controlangles of attack during the whole trajectory were analyzed. Calculation results show thecomputational astringent rate fast and the various constraints fulfilled, and verify the methodis feasible and efficient.This dissertation has some theoretical significance in extending the research domain ofoptimization on aircraft designing at the initial stage, exploring a basic framework aboutoptimization on overall parameters and trajectory parameters. Meanwhile, its applicationbackground is the optimization on the takeoff mass of small cruise vehicle and controlparameters of reentry vehicle. The obtained achievements based on theoretical researches area good reference to the subsequent study. |
