NPP Monitoring Missions via a Multi-Fleet of Drones: Reliability Issues

Background

Aghaei et al. (2017) investigate the redundancy allocation problem for a k-out-of-n system with a choice of redundancy strategies, which can be applied for drone fleets and multi-fleets of drones. In contrast to the existing approaches that often consider a predetermined strategy for each subsystem, the authors consider both active and standby strategies and developed a model to select the best strategy for each subsystem. Eryilmaz et al. (2017) present the reliability analysis of a weighted-k-out-of-n:G system consisting of two types of components. The system is assumed to have n components which are classified into two groups with respect to their weight and reliability, and it is assumed to operate if the total weight of all working components exceeds a prespecified threshold. This model can be used in case of heterogeneous fleet reliability assessment. Byun et al. (2017) propose the matrix-based system reliability method extended to k-out-of-n systems by modifying the formulations of event and probability vectors. The proposed methods can incorporate statistical dependence between component failures for both homogeneous and non-homogeneous k-out-of-n systems, and can compute measures related to parameter sensitivity and relative importance of components. The described method can be used in case of drones failures and control stations of different fleets failures dependencies. Pascual-Ortigosa et al. (2018) review the different definitions that multistate k-out-of-n systems have received and show how the algebraic method is used to study their reliability in a general way with a single approach. Considering a system with different requirements on the number of working components (i.e., value of k) for different system state levels, Mo at al. (2015) propose a new analytical method based on multi-valued decision diagrams for the reliability analysis of such multi-state k-out-of-n systems. These results could be used in case of application of multi-functional drones with assumed degradation of the functions. Based on the results of this work and taking into account the control station reliability, the aim of the paper is to develop models for a multi-fleet of drones with two-level hot standby redundancy considering a control system structure features.