Improved interval-fuzzy quadratic programming for management of filters in a fluid power system under uncertainty

An improved mathematic model of management of filters in a fluid power system (FPS) under uncertainty was developed in this article based on the former hybrid optimization method. The model integrated the interval-fuzzy quadratic programming model into an improved model of contaminant control for the selection of filters finenesses, the estimation of service life of pumps, and replacement strategies of filters in an FPS under uncertainty. The fuzzy quadratic optimization approach was used in the model to handle the uncertainties existing not only in the contaminant holding capacity, but also in the contamination level and contaminant sensitivity. The integrated model has been applied in a case of selecting filter fineness and planning allocation and replacement strategies under uncertainty for an FPS with bypass filtration circuit. All of the scenarios with available filter fineness have been examined. The generated decision alternatives can help decision makers to identify desired policies for contamination control under various total costs, satisfaction degrees, and system-failure risks under different contaminant ingression/generation rates.