Time Synchronization of Multi-Sensor Systems using Generalized Precision Time Protocol (gPTP): Enabling Precise Sensor Fusion for Autonomous Platforms

Time synchronization is a critical enabler for multi-sensor fusion in autonomous platforms. This article explores the implementation and optimization of Generalized Precision Time Protocol (gPTP) for achieving sub-microsecond temporal alignment across heterogeneous sensors, including cameras, LiDARs, and radars. The IEEE 802.1AS standard provides a robust framework that overcomes limitations of traditional synchronization methods through hierarchical clock structures and hardware timestamping. The architecture incorporates time-aware network infrastructure, multiple sensor integration approaches, and precise data acquisition mechanisms. Experimental evaluations demonstrate that gPTP-synchronized sensors achieve nanosecond-level precision that significantly improves perception accuracy and tracking continuity across varying speeds and scenarios. Position estimation errors are substantially reduced at highway speeds, while track losses during complex maneuvers are nearly eliminated. Implementation challenges, including non-PTP capable sensors, network congestion, and heterogeneous clock domains, are addressed through innovative solutions such as FPGA bridge modules, Time-Sensitive Networking mechanisms, and advanced compensation algorithms. Controlled degradation experiments establish clear thresholds for synchronization requirements, confirming that sub-millisecond precision is essential for safe operation at urban and highway speeds. These findings establish precise temporal alignment as a fundamental requirement for reliable environmental perception in dynamic autonomous systems.