Research On High Precision Clock Synchronization Technology Based On IEEE1588 Protocol

With the wide application of distributed system and network technology,clock synchronization,as an indispensable technology in the field of network measurement and control,ensures the coordination and accuracy of the working process of distributed test system.When the distributed test system is running,the accurate clock synchronization technology can provide a unified time benchmark to ensure the coordinated work of each node,so as to realize effective measurement and control.Therefore,it is of important reference value to study a high-precision clock synchronization technology scheme that meets the current engineering needs.This paper analyzes the basic principles and implementation method,and proposes a high-precision clock synchronization technology implementation scheme based on IEEE1588 protocol.The main research contents and results are as follows:(1)This paper deeply studies the basic theory and implementation principle of clock synchronization technology,analyzes and compares the advantages and disadvantages and differences of several traditional clock synchronization technologies,among which the IEEE1588 clock synchronization protocol can achieve nanosecond synchronization accuracy in the distributed test system.So the IEEE1588 protocol of PTP system clock type,PTP message format,PTP clock synchronization principle,transparent clock synchronization mechanism and best master clock algorithm are introduced.(2)Based on the basis of IEEE1588 protocol,an effective high-precision clock synchronization scheme is proposed through the combination of software and hardware.Among them,the hardware part mainly selects the STM32F407 microprocessor to form the PTP clock synchronization system,selects the LAN8720 A chip as the PHY chip,and obtains the time stamp at the RMII interface between the MAC layer and the PHY layer.The software part is mainly composed of PTP state machine,the best main clock algorithm,message sending and receiving and processing,local clock algorithm adjustment,Lw IP communication protocol,etc.(3)In view of the clock frequency drift problem in the PTP clock synchronization system,analyzed the influence of clock drift on synchronization accuracy,and put forward a clock state synchronization correction algorithm,using the clock deviation and the clock drift,and realize the real-time correction of clock deviation and clock drift.Meanwhile,the sliding average filtering is used to eliminate the frequency jitter and random error in the synchronization process.Simulation results show that the clock state synchronization correction algorithm effectively controls the clock deviation below 100 ns and implements the nanosecond network pair time.(4)Through experimental simulation and hardware platform,the clock synchronization scheme is tested by master and slave clock,the synchronization performance of PTP system is verified according to the collected experimental data,and the related factors affecting the synchronization accuracy are analyzed.Experimental results show that the synchronization accuracy can reach 50 ns.Therefore,this scheme meets the synchronization accuracy requirements of most engineering applications.