A layered architecture for real time applications

The paper argues that real time control systems should be structured in abstraction layers in provide adequate instruction formalisms for both task specification and for low level control, and that the design information used when specifying the system should be included in the encoding of the abstraction barrier. When this design information is available, describing the semantics of the abstraction, the problems with interdependencies between real time control and task level operation can be handled. An example of a system encompassing this principle-Aramis-is presented. The paper discusses how this principle can be utilised to analyse the system and for error recovery support.