复杂系统可靠性冗余的遗传算法

GENETIC ALGORITHM OF RELIABILITY REDUNDANCY IN COMPLEX SYSTEM

冗余技术是提高系统可靠性与安全性的重要途径。复杂系统冗余优化设计问题难度较大 ,至今没有很好地解决。本文论述了用遗传算法解决这一问题的思路和方法 ,通过算例验证了该算法的有效性。

Redundancy technology is an important method of improving reliability and security in system. The optimization in complex system is an rather difficult problem and has no satisfied method up to now. In this paper, the thought way how to apply genetic algorithm in this problem is discussed. Genetic algorithm is one of the efficacious search method based on nature choice and the principle of gene genetics. The feature of genetic algorithm is to process the code of parameter in stead of parameter self. It has three main operators namely reproduction, crossover and mutation. The essence of reproduction is optimization of the old population. The crossover operator can make new individuals and avoid converging at local optimization. The mutation operator will prevent valuable genetic information from losing too early. The application of genetic algorithm is introduced with an bridge system in this paper. We adopt binary system alphabet {0,1} in coding and use 4 bit code length. Because the object function is the system cost, the fit value of individual should reduce as system cost raises. To complete crossover, the location, direction and individual number of crossover should be determined at random. The probability of mutation is 1/ n (where n is individual number in population). There are 100 individuals in original population. After experiencing heredity of 100 generations, the optimal solution is obtained. Fig.3 illustrates that average cost of generations decreases as genetic generations increases and gradually goes to the stable status. In the end, the efficiency of genetic algorithm is verified by an practical example. As mentioned above, genetic algorithm is an efficient search method in complex space. It can be easily applied to solve the problem of optimal redundancy in complex system.