Consensus Clock Synchronization for Distributed Satellite System Based on Distributed PI Controller

Distributed satellite system (DSS) composed of large scale low-orbit satellites is the inevitable trend of future satellite applications, and the low-cost and high-precision clock synchronization of the satellite network is a core technology. At present, the main method of satellite network clock synchronization is still the master-slave structure based on step by step transmission. Although this method is simple, the clock synchronization performance and flexibility are poor, which is not suitable for large-scale satellite networks. This paper proposes a consensus clock synchronization method for DSS based on a distributed PI controller. Each satellite clock node is regarded as an agent, and the multi-agent consensus theory is introduced to make full use of the measurement links between adjacent satellites. As a result, the low-cost and high-precision clock synchronization method for DSS reaches sub-nanosecond level. Simulation experiments also show that the method can converge quickly and the clock synchronization precision is better than 0.1ns, which can meet the needs of clock synchronization for large-scale low-orbit DDS in the future.