Abstract: For the scheduling of hybrid tasks for software CNC, a two-level hierarchical scheduling scheme is presented. The time-triggered mode and event-triggered mode are adopted for the real-time periodic tasks and real-time aperiodic tasks respectively. Firstly, the task model is established and the related concepts are defined. Then, the structure of scheduling scheme is proposed, and scheduling algorithm, schedulability and tick-interval are deeply researched. Subsequently, the scheduling scheme is adopted for the software CNC based on Windows CE.NET, and software CNC structure and task division are analyzed. Finally, the experimental verification of two-level hierarchical scheduling scheme is carried out and the results demonstrate that the proposed method can ensure the determination of real-time tasks, and improve the performance of software CNC system.

Key words: Hybrid tasks, Software CNC, Two-level hierarchical scheduling, Windows CE.NET, ASA 3D temperature field Target function Integrated optimization