The paper presents a feedback scheduling mechanism in the context of co-design of the scheduler and the control tasks. We are particularly interested in controllers where the execution time may change abruptly between different modes, such as in hybrid controllers. The proposed solution attempts to keep the CPU utilization at a high level, avoid overload, and distribute the computing resources evenly among the tasks. The feedback scheduler is implemented as a periodic or sporadic task that assigns sampling periods to the controllers based on execution-time measurements. The controllers may also communicate feedforward mode-change information to the scheduler. As an example, we consider hybrid control of a set of double-tank processes. The system is evaluated, from both scheduling and control performance perspectives, by co-simulation of controllers, scheduler, and tanks.
In addition they have investigated feedback scheduling of the control tasks REF where the period of control tasks is adapted during run-time.
Feedback scheduling of control tasks
Proceedings of the 39th IEEE Conference on Decision and Control (Cat. No.00CH37187)
Proceedings of the 39th IEEE Conference on Decision and Control (Cat. No.00CH37187)
Computer Science