System-Level Offline Time Synchronization Architecture for Distributed Electrical Signal Monitoring Using Raspberry...

Area of Science:

• Electrical Engineering
• Computer Science
• Embedded Systems

Background:

• Accurate time synchronization is crucial for distributed electrical signal monitoring, enabling phase coherence and event correlation.
• Traditional synchronization methods (NTP, GPS) are often impractical for offline, isolated, or budget-constrained systems.
• Existing solutions lack robustness in autonomous, self-contained environments.

Purpose of the Study:

• To develop and validate an autonomous offline time synchronization architecture for multi-node monitoring systems.
• To demonstrate sub-microsecond inter-node alignment using commodity hardware without external time references.
• To verify the system's reliability and recovery capabilities under various conditions, including power loss.

Main Methods:

• Implementation of a multi-mechanism synchronization strategy on Raspberry Pi 5 platforms.
• Integration of Real-Time Clock (RTC) persistence, systemd orchestration, and automated boot recovery.
• Utilization of chrony for Network Time Protocol (NTP) discipline and Precision Time Protocol (PTP) hardware timestamping (PHC).
• Validation through long-term stability, inter-node phase coherence, and jitter measurements.
• Testing under controlled power-loss scenarios and signal-level timestamp alignment verification.

Main Results:

• Achieved sub-microsecond time synchronization between nodes in a fully offline configuration.
• Demonstrated reliable synchronization using only low-cost, commodity embedded hardware.
• Verified robust recovery behavior following simulated power interruptions.
• Confirmed inter-node timestamp alignment using hardware and software validation methods.

Conclusions:

• The developed architecture provides reliable, long-duration time synchronization for offline embedded systems.
• Low-cost hardware solutions can effectively meet stringent timing requirements in distributed monitoring.
• The system offers a practical alternative for applications where external synchronization sources are unavailable or unsuitable.