Experimental Analysis of Primary-Shadow Replication Scheme for Fault-Tolerant Operational Flight Program of Small Scale UAV

This paper proposes to use a time-driven fault-tolerant mechanism motivated from Primary-Shadow TMO's Replication (PSTR)[7,8] scheme for embodying fault-tolerant capability in Operation Flight Program (OFP) of small Unmanned Aerial Vehicles(UAV). The advantage of the time-driven fault-tolerant mechanism is considered as quick detection and rectification of system failure within minimum period. For the feasibility test, a Hardware-In-the-Loop Simulation (HILS) environment containing dynamics model of a small scaled unmanned helicopter has been developed and integrated with primary and shadow FCCs through RS-232 duplicators and switchers. Various failures and deadline violations in receiving data from sensors, calculating control logics and sending control data to actuators were simulated and tested within the HILS. This paper explains the time-driven fault-tolerant mechanism and experimental environments in details, and illustrated the results of various experiments to convince the practical applicability of the proposed mechanism.