Time synchronization using distributed observer algorithm with sliding mode control element in wireless sensor networks

Abstract

This paper describes a novel distributed observer algorithm which uses augmented sliding mode control element for time synchronisation purpose in a wireless sensor networks (WSN). Time synchronisation is a prevalent and an important issue in the field of WSN. Local clocks on each nodes within any interconnected WSN should have exchanged messages with a common time reference. Referencing to a distinct (unsynchronised) value of virtual global reference clock will render the nodes communication and application in WSN useless. The algorithm proposed in this paper known as Time Synchronization using Distributed Observer algorithm with Sliding mode control element (TSDOS) features a useful switching action, common in control research, which provides a salient feature in guaranteeing finite-time convergence in synchronised virtual time clock estimation error. The main purpose is to achieve global clock synchronization with faster convergence speed and reduced synchronization error. TSDOS has the characteristics of being totally distributed, asynchronous, scalable across different network topological structures and robust to adhoc nodes deployment and link failures. Communication link node deployment and link failure scenario are simulated comprising of 9 WSN nodes. The adoption of TSDOS shows that the faster convergence in time synchronization has been successfully achieved in comparison to the conventional distributed scheme.