An Adaptive Fuzzy-PI Clock Servo Based on IEEE 1588 for Improving Time Synchronization Over Ethernet Networks

Abstract

A network-based control system includes many connected devices, and time synchronization plays an important role in the unified operation of those systems. A clock servo needs a guarantee time offset and a clock rate to minimize the time difference between devices. This paper proposes an adaptive clock servo to improve time synchronization. This proposed algorithm uses a fuzzy-based proportional-integral clock servo (fuzzy-PI) based on IEEE 1588 to reduce the frequency of clock compensation. This method adapts the bandwidth and enhances noise reduction, improving both the time offset and rate difference between the slave and master. The node time can synchronize with the master time after just one cycle of synchronization. Experiments validated the effectiveness of the algorithm and demonstrated that the slave can track the master with the mean and standard deviation of the time offset are 0.432ns and 4.402ns. A cycle time of one second is used to ensure a low-bandwidth network. With these results, the number of nodes over a real-time network can be increased.

A Novel Time Synchronization Method for Smart Grid Based on Improved Wolf Colony Algorithm-Cuckoo Search Optimized Fuzzy PID Controller

“…16 that the errors calculated by the proposed method in this paper are smaller than that of the other two compared methods. In addition, the average errors of the proposed method, the method in [8] and [20] are -15.23μs, -5.38μs, and 0.76μs, respectively. obviously, the minimum synchronization error is obtained with the hybrid IWCA-CS optimizing fuzzy PID controller.…”

“…In this subsection, the proposed hybrid IWCA-CS tuned fuzzy PID controller is employed to synchronize the time of the collection terminal and the electric meters, and the time synchronization between the master station and data collection terminal is not narrated to avoid prolonging discussion. In addition, we make a comparison of it with the wolf colony algorithm-based PID controller [8] and an adaptive fuzzy-PI clock servo [20]. In the experiment, the time of data collection terminal is regarded as the standard time.…”

“…In [17], a fuzzy PID control system is designed to perform load frequency control of multi area interconnected power systems. In paper [20], an adaptive clock servo is proposed to improve time synchronization, which uses a fuzzy PI clock servo based on IEEE1588 to reduce the frequency of clock compensation. However, the study on fuzzy PID controller employed in the field of time synchronization is immature, and using self-tuning method to regulate the fuzzy logic parameters (fuzzy rules, scaling factors, membership functions) is usually inadequate to obtain the optimal parameters resulting in adverse effect on system performance.…”

Clock Synchronization Algorithm of Distributed System Based on Adaptive Technology

“…Compared with the constant clock of the integrated system, the distributed system does not have a fixed and unified time or a prescribed time, but the distributed system has higher requirements for clock coordination, such as job scheduling, multitasking, coordination algorithms, etc. [9][10]. In order to reduce the impact of wrong time on DCS, a physical or logical clock should be set as the master clock in the distributed system, and other nodes in the system use the master clock for time-related operations [11].…”

10 Gigabit White Rabbit: Sub-Nanosecond Timing and Data Distribution

“…The phase noise results depend on the response of the phase control servo loop inside the Timing Controller that is implemented by means of a simple PI controller although advanced techniques could be used [47]. Therefore, a tuning process has been performed to obtain the optimal values for the proportional and integral terms of the control loop (k p and k i ).…”