Research of Three-level Scheduling Model Oriented to CNC Systems

To support the characteristics of hard real-time system,where several types of tasks can coexist simultaneously,in this paper we present a new three-level real-time scheduling(TLRtS) model which is designed to integrate many well-known scheduling algorithms dynamically in one model.The model divides the whole system space into three parts in order to deal with hard real-time,soft real-time and non-real time tasks respectively.The tests show that the proposed method can enhance the Quality-of-Service of soft real-time and non-real time tasks without jeopardizing the guarantee of hard real-time deadlines.