Design and Research of a Synchronization Method for a Triple Redundant Flight Control System

In order to improve the reliability of the flight control system of unmanned aerial vehicle (UAV), the management strategy of redundancy is designed based on the sample flight control computer with distributed architecture. To solve the difficult synchronization problem between CPUs and accumulating error on the time drift after synchronization, the time synchronization of CPUs is realized by integrate task synchronization algorithm with simplified TPSN synchronization algorithm, which decreased the influence of time drift efficiently and improved the synchronous accuracy to 0.1 milliseconds. Then the choice of the output channel from the three channels is dependent on ‘distance’-based encapsulation voting algorithm, which decreased the developing difficulty and code redundancy in traditional way. And reconstruction strategy is adopted to manage CPU fault, which increased the reliability of system through system degradation and failure recovering. Finally, a function testing for these key points, the result shows that these points can meet functional requirement and technical index, through which the efficiency and reliability of the proposed redundancy management strategy is verified.