The authors study the safety reconfiguration of embedded control systems following component-based approaches from the functional level to the operational level. At the functional level, a Control Component is defined as an event-triggered software unit characterized by an interface that supports interactions with the environment (the plant or other Control Components). They define the architecture of the Reconfiguration Agent, which is modelled by nested state machines to apply local reconfigurations. The authors propose technical solutions to implement the agent-based architecture by defining UML meta-models for both Control Components and also agents. At the operational level, a task is assumed to be a set of components having some properties independently from any real-time operating system. To guarantee safety reconfigurations of tasks at run-time, the authors define service and reconfiguration processes for tasks and use the semaphore concept to ensure safety mutual exclusions. They apply the priority ceiling protocol as a method to ensure the scheduling between periodic tasks with precedence and mutual exclusion constraints.
Multicast dataset synchronization and agent negotiation in distributed manufacturing control systems
