Design and Implementation of a Switching Controller for Transient Improvement in a Time Synchronization System

Currently, many large and complex systems, such as telecommunication systems, power systems, and automated manufacture systems, require their distributed clocks to be synchronized to the master clock. This paper discusses implementation of a distributed embedded time-synchronized system, based on the IEEE 1588 standard. Two important requirements exist in time synchronization. One is that the clocks be synchronized at maximum speed. The other is that the clocks operate at optimum precision and accuracy over the long term. This paper proposes a switching controller, which combines a fuzzy control scheme and a traditional proportional integral (PI) control scheme to meet the aforementioned two requirements. The traditional PI control scheme was used in the steady state, whereas the fuzzy control scheme was adopted in the transient stage. The experimental results showed that in the fuzzy control scheme, transient time, which is the length of time in the transient state, was reduced to 50% of the transient time in the PI control scheme.