关键词: 随机Petri网, 蚁群算法, 路经序列, 可靠性, 维修性

Abstract: Many problems in engineering can be modeled as the mainframe route sequence search problem based on a Stochastic Petri Net（SPN）.Supposing that a unit represented by a transition is restorable，reliability and maintenance degree of a transition obeys Weibull distribution and lognormal distribution respectively，and then the concept of generalized maintenance time is put forward，and the steady state availability formulas of a unit and a system are obtained respectively.In order to find the mainframe route sequence，a SPN with Memorability and Availability（SPNMA），whose elements can record a little information，is proposed based on the ant colony optimization algorithm and features of SPN.When SPNMA is running，enough tokens walk and leave pheromone on the complicated SPNMA.Synthetic cost and steady state availability of transitions and pheromone on transitions are the primary base to adjust route choice of tokens.Pheromone weight multiplier of normal distribution，pheromone balance operator of uniform distribution and stochastic tokens are introduced to improve the ant colony optimization algorithm.Ants give priority to select routes with lower synthetic cost.At last a clear ant route can be found on the route with the lowest synthetic cost.The result of simulation shows that the clear ant route is formed along the best route effectively by tokens.

Key words: stochastic Petri net, ant colony algorithm, route sequence, reliability, maintainability