A Novel Simulation Approach to Extended Dynamic Fault Trees Analysis for Highly-reliable Satellite OBDH Subsystem

Abstract

On-board data handling (OBDH) subsystem is the critical subsystem of satellite which is supplied with hot/warm/cold spare backups, also uses triplicated bus and redundant memories for high reliability. For satellite OBDH subsystem, we present an extended dynamic fault tree model (eDFT). Because analytic approach is restricted to particular models and some probability distributions of fault rate, we use Monte Carlo simulation to analysis eDFT instead of it. However, it needs much long time to implement Monte Carlo simulation, so we provide the transformation approach to accelerate the Monte Carlo simulation. Each eDFT gate can be implemented by logic gate of mathematical circuit. The analysis result of the approach shows that acceleration value changes over the size of the eDFT-TTFT units, number of FPGA logic gates of random number generators, and number of FPGA logic gates of TTFT, so this approach can be more accurate and much faster than computer- based simulation.