A Scheduling Algorithm of Events with Uncertain Timestamps for CPS
Fangfang Li, Chong Liu, Ge Yu, Zhe Chen · 2017
Cyber-Physical System is a novel intelligent system integrating computing and physical procedures, which combines computing, communication and control technologies. Event is the key element to link the cyber world and the physical world. However, the time stamp of the event is imprecise in practical applications because of data loss, mismatching of the time granularities of events from different monitoring systems, or asynchronism of events in the distributed systems and so on. We improve the Low Water Mark algorithm originally designed for the event scheduling with deterministic timestamps by leveraging tailored pruning techniques considering the time uncertainty. Specifically a scheduling algorithm of events with uncertain timestamps is proposed, which can support effective scheduling of reading events and writing events in CPS. The experiments verify that the scheduling algorithm is more accurate, which guarantees providing correct feedback of the event sequences to CPS.