Intensive studies have been carried out on generations of waverider geometry and hypersonic inlet geometry.However,integration efforts of waverider and related air-intake system are restricted majorly around the X43A-like or conical flow feld induced confguration,which adopts mainly the two-dimensional air-breathing technology and limits the judicious visions of developing new aerodynamic profles for hypersonic designers.A novel design approach for integrating the inward turning inlet with the traditional parameterized waverider is proposed.The proposed method is an alternative means to produce a compatible confguration by linking the off-the-shelf results on both traditional waverider techniques and inward turning inlet techniques.A series of geometry generations and optimization solutions is proposed to enhance the lift-to-drag ratio.A quantitative but effcient aerodynamic performance evaluation approach(the hypersonic flow panel method) with lower computational cost is employed to play the role of objective function for optimization purpose.The produced geometry compatibility with a computational fluid dynamics(CFD) solver is also verifed for detailed flow feld investigation.Optimization results and other numerical validations are obtained for the feasibility demonstration of the proposed method.
In order to achieve the optimal attack outcome in the air combat under the beyond visual range(BVR)condition,the decision-making(DM)problem which is to set a proper assignment for the friendly fighters on the hostile fighters is the most crucial task for cooperative multiple target attack(CMTA).In this paper,a heuristic quantum genetic algorithm(HQGA)is proposed to solve the DM problem.The originality of our work can be supported in the following aspects:(1)the HQGA assigns all hostile fighters to every missile rather than fighters so that the HQGA can encode chromosomes with quantum bits(Q-bits);(2)the relative successful sequence probability(RSSP)is defined,based on which the priority attack vector is constructed;(3)the HQGA can heuristically modify quantum chromosomes according to modification technique proposed in this paper;(4)last but not the least,in some special conditions,the HQGA gets rid of the constraint described by other algorithms that to obtain a better result.In the end of this paper,two examples are illustrated to show that the HQGA has its own advantage over other algorithms when dealing with the DM problem in the context of CMTA.
Optimization problems are often highly constrained and evolutionary algorithms(EAs)are effective methods to tackle this kind of problems. To further improve search efficiency and convergence rate of EAs, this paper presents an adaptive double chain quantum genetic algorithm(ADCQGA) for solving constrained optimization problems. ADCQGA makes use of doubleindividuals to represent solutions that are classified as feasible and infeasible solutions. Fitness(or evaluation) functions are defined for both types of solutions. Based on the fitness function, three types of step evolution(SE) are defined and utilized for judging evolutionary individuals. An adaptive rotation is proposed and used to facilitate updating individuals in different solutions.To further improve the search capability and convergence rate, ADCQGA utilizes an adaptive evolution process(AEP), adaptive mutation and replacement techniques. ADCQGA was first tested on a widely used benchmark function to illustrate the relationship between initial parameter values and the convergence rate/search capability. Then the proposed ADCQGA is successfully applied to solve other twelve benchmark functions and five well-known constrained engineering design problems. Multi-aircraft cooperative target allocation problem is a typical constrained optimization problem and requires efficient methods to tackle. Finally, ADCQGA is successfully applied to solving the target allocation problem.
针对遗传算法收敛速度慢,容易"早熟"等缺点,提出了一种改进的遗传算法,即基于云模型的自适应并行模拟退火遗传算法(PCASAGA,Adaptive Parallel Simulated An-nealing Genetic Algorithms Based On Cloud Models).PCASAGA使用云模型实现交叉概率和变异概率的自适应调节;结合模拟退火避免遗传算法陷入局部最优;使用多种群优化机制实现算法的并行操作;使用英特尔推出的线程构造模块(TBB,Threading Building Blocks)并行技术,实现算法在多核计算机上的并行执行.理论分析和仿真结果表明:该算法比其他原有的或改进的遗传算法具有更快的收敛速度和更好的寻优结果,并且充分利用了当前计算机的多核资源.
