Improvement Of Small-world Algorithm And Its Application In Design Of Flight Control System

Small-world networks have been widely used in the application field of enterprise management, network information, biology, etc. Recently, small-world algorithm becomes a new application field of s mall-world networks. Imitating the high efficiency of information transfer in the small-world network, small-world algorithm has the advantages of simple search operator configurationand excellent global search ability, which attracted the attentions of researchers all over the world. A research aiming at improving the flaws of small-world algorithm such as the isolation of node information, low efficiencyof local short- link search has been presented in this paper. The improved small- world algorithm was applied into the simulation optimal design of airplane automatic flight control system. The following work has been carried out in this paper:1. The structure and the characteristics of small- world networks are comprehensively analyzed. The principle, steps and the shortcomings of simple smallworld algorithm were described in detail to lay the foundation for further research of algorithm improvement.2.In orderto overcome the shortcomings of the simple small- world algorithm such as the isolation of node information and low efficiency of local short-link search, this paper adopted a linear variation of local short-link search possibility and node neighborhood size, a new type of local short- link search strategy and e lite selection strategy, thus proposed a balanced type of small- world algorithm. Tests show that comprehensive optimization performance of balanced type of the small-world algorithm is superior to the simple small- world algorithm, but it is worse than the simple genetic algorithm. A new hybrided type of small- world algorithmis obtained through the cross- fertilizing of balanced small-world algorithm and traditional nonlinear programming. Tests show that this hybrid type of small- world algorithmis much better than simple small-world algorithms, balanced type of small-world algorithm and simple genetic algorithm.3.Apenalty function method has been used to deal with constraint conditions, which enables the balanced type of small- world algorithm and the hybrided type of small- world algorithm to treat problems involving constraint conditions. Tests show that the comprehensive performance of balanced small- world algorithm is better than the simple small-world algorithm and worse than simple genetic algorithm in dealing with problems involving constraint conditions; the comprehensive performance of hybrided type of small-world algorithmis better than the simple small- world algorithm, balanced type of small-world algorithm and simple genetic algorithm in dealing with problems involving constraint conditions.4.The simple small- world algorithm, balanced type of small-world algorithm, hybrided type of small- world algorithm and simple genetic algorithm are applied to optimization design of the aircraft automatic control system. Experiments show that the design effect of 4 kinds of optimization algorithmis obviously superior to the root locus method. The design effect of balanced type of small- world algorithm is superior to the simple small-world algorithm, but it is inferior to the simple genetic algorithm. The design effect of hybrided type of small- world algorithm is better than the simple small- world algorithm, balanced type of small- world algorithm and simple genetic algorithm.5.Combine the Simulink of MATLAB software modules and Flight Gear flight simulator through the UDP communication interface. A visual simulation of automatic has been designed by hybrid small- world algorithmand displayed the automatic flight process.