Title :
Timestamping Uncertainties in Distributed Data Acquisition Systems
Author :
Bezet, Olivier ; Cherfaoui, Véronique
Author_Institution :
Univ. de Technologie de Compiegne
Abstract :
This paper describes a solution for on-line and postprocessing timestamping synchronization in a distributed architecture embedded for example in an experimental vehicle. Interval timestamping is used, taking into consideration sensor latency, transmission delay and clock granularity. This solution does not change local system clocks, so that the network configuration can change without affecting timestamping precision. All nodes of the network are connected via a synchronous bus network (here, the FireWire, IEEE 1394). The bus clock is used to estimate the drift of all computer clocks in order to exchange data timestamps with high precision and to compute time equivalences between the different clocks for postprocessing timestamping synchronization. Experimental simulations show the advantages of the solutions. The timestamping synchronization methods are well adapted to dynamic applications, where data timestamping is important for real time considerations. An application in the field of intelligent vehicles has been implemented
Keywords :
automated highways; clocks; data acquisition; distributed processing; sensor fusion; synchronisation; system buses; FireWire IEEE 1394; bus clock; clock drift estimation; clock granularity; computer clocks; data acquisition systems; distributed architecture; distributed sensor systems; intelligent vehicles; interval timestamping; local system clocks; network clock; network configuration; sensor latency; synchronous bus network; timestamping synchronization; timestamping uncertainties; transmission delay; Application software; Clocks; Computational modeling; Data acquisition; Delay; Firewire; Intelligent vehicles; Synchronization; Uncertainty; Vehicle dynamics; Clock drift estimation; Data acquisition; Distributed sensor systems; Intelligent vehicles; Interval timestamping; Network clock; Timestamping synchronization;
Conference_Titel :
Instrumentation and Measurement Technology Conference, 2005. IMTC 2005. Proceedings of the IEEE
Conference_Location :
Ottawa, Ont.
Print_ISBN :
0-7803-8879-8
DOI :
10.1109/IMTC.2005.1604553
