路灯维护总费用随机优化模型及其概率分布拉格朗日松弛方法

针对一般故障特性的部件,优化其有限阶段内更换策略尚无相关模型及有效的解决办法.本文为路灯维修问题建立了联合更换部件的多阶段随机策略优化模型.策略优化难点在于部件更换的相互耦合,且其耦合约束为难以处理的随机约束.不同于现有的基于情境松弛随机耦合约束的方法,本文通过引入与决策概率分布相关的乘子松弛约束,给出概率分布拉格朗日...

Stochastic model for total cost optimization in street lamp maintenance and its probabilistic Lagrangian relaxation method

Optimization models and algorithms for the maintenance policy of components with general failure modes in a finite horizon still remain a challenge. This paper provides a multi-stage stochastic model to optimize the joint replacement policy for street lamp components of general failure modes. The major difficulty arises from the stochastic coupling constraints on different component replacement decisions. Instead of relaxing those constraints based on scenarios as in existing methods, we propose the probability Lagrangian relaxation method(PLR) by introducing multipliers ssociated with the probability distributions of decisions, where the number of multipliers is independent of the exponentially increasing scenarios. A solution method and its sufficient conditions are also provided for a phase-wise policy structure to decouple the correlation among stages due to the time-variant failure rates. In numerical testing with real data, the PLR obtains the lower bound of the optimal solution and a suboptimal solution. The results lead to a significant reduction in the current maintenance cost, and demonstrate the efficiency of the model and PLR in solving practical problems.