Reservation based protocol for resolving priority inversions in composable conveyor systems

We present a reservation based protocol for resolving priority inversions in Composable Conveyor Systems. These systems represent a class of networked multi-processor systems that are used to physically transport entities from inputs to outputs. The absence of shared memory and the interaction between the cyber and physical subsystems present many challenges such as priority inversion. We view the end-to-end transport of an entity as a task and discuss how these systems admit a rich set of task models. Like in other real-time systems, a priority inversion is said to occur when a high-priority task is blocked by a lower-priority task for an unbounded duration of time. We present an approach to compute the average waiting time for entities, establish properties of the proposed protocol and present simulation results that demonstrate the efficacy of the proposed protocol. In the future, this protocol can be extended to other task models and a larger class of decentralized systems for advanced manufacturing.