Average consensus theory is intensely popular for building time synchronization in wireless sensor networks (WSN). However, the average consensus-based time synchronization algorithm is based on iteration that poses challenges for efficiency, as they entail high communication cost and long convergence time in large-scale WSN. Based on the suggestion that the greater the algebraic connectivity leads to the faster the convergence, a novel multi-hop average consensus time synchronization (MACTS) is developed with innovative implementation in this paper. By employing multi-hop communication model, it shows that virtual communication links among multi-hop nodes are generated and algebraic connectivity of network increases. Meanwhile, a multihop controller is developed to balance the convergence time, accuracy, and communication complexity. Moreover, the accurate relative clock offset estimation is obtained by delay compensation. Implementing the MACTS based on the popular one-way broadcast model and taking multi-hop over short distances, we can easily achieve the fast convergence MACTS.

Time synchronization is important for coordination and control in multiple robot networks. Two-way time message exchange (TTME) time synchronization is efficient, but due to variable response latency, it does not completely meet the requirements for quadrotor robot groups. Aiming to provide accurate time synchronization for robots, the proposed quick TTME synchronization starts a downlink after an uplink quickly and tries to maintain a fixed clock offset for the estimation. A timeout constraint is used to filter invalid observations and optimize clock offset estimation. This avoids the increasing clock offset caused by large software latencies and communication link delays, guarantees a fixed clock offset for TTME, and provides precise and stable clock offset estimation for time synchronization in robot networks.