Supporting the hard real-time requirements of mechatronic systems by 2-level interrupt service management

Mechatronic systems often require hard real-time behaviour of the controlling system. The standard solution for this kind of application is based on the time-triggered approach, and for certain circumstances the schedulability is provable. In contrast to this, the approach in this paper introduces some hardware enhancements that allow first to substitute the time-triggered system by an event-triggered system and second to enhance the event-triggered system by a two-level reaction system while conserving the hard real-time capabilities. This results in a hard-time-but-weak-logic reaction system when computing time is tide but maintains full processing capabilities and therefore exact reaction values for all reactions whenever possible. Combining two or more events will improve the theoretical schedulability of the system too.