Distributed Clock Synchronization via Feedback Tuning Loop
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Solution Overview
Problem
High-performance systems, such as aircraft, require highly accurate time synchronization between distributed devices, typically using a serial data interface, but face challenges due to electronic noise and interference, necessitating sub-microsecond synchronization accuracy.
Innovation Solution
A method and system for synchronizing a local clock with a master clock using a serial communication bus, involving a frequency tuning loop that generates a time error signal and produces an updated local time signal, ensuring accurate timekeeping across distributed devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electronic clocks are used in distributed devices for time-keeping, then each device can independently track time, but the timing drifts apart due to inherent clock drift
Solution Approach 1:
The patent implements a feedback mechanism where the master clock sends time synchronization signals to distributed devices, which compare their local clock time with the master clock time and adjust their local clocks accordingly. This closed-loop feedback system continuously corrects time drift, ensuring all devices maintain synchronized time despite inherent clock inaccuracies.
2Reliability
If serial data interface is used for transmitting time synchronization data, then communication can be established in harsh environments, but achieving sub-microsecond synchronization accuracy becomes challenging due to noise and interference
Solution Approach 1:
The patent employs differential signaling methodology that inherently compensates for electromagnetic interference and noise before they can corrupt the time synchronization data. By using twisted-wire pairs with differential voltage signaling, the system pre-empts the harmful effects of electrical noise, ensuring that even in harsh electromagnetic environments, the time synchronization signals maintain sub-microsecond precision.
Data Source
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AI summary
A method and system of synchronizing a local clock with a master clock using a serial communication bus includes receiving by a serial data interface receiver a master time signal corresponding to a master clock, generating by a frequency tuning loop a time error signal corresponding to a difference between the master time signal and a local time signal, generating by the frequency tuning loop an actual frequency signal based on a base frequency and the time error signal, producing by the frequency tuning loop a command frequency error based on the actual frequency signal and the local time signal, and producing by the local clock an updated local time signal based on the command frequency error.