From time-optimal schedule to robust event-based control

In this work in progress paper, we formulate performance robust event-based control strategies with respect to uncertainties in operation processing times. The proposed policies are based on a time-optimal schedule of operation sequences. A logical operation model is used to specify relations between operations. The control policies generate conditions ensuring to maintain the execution order given in the schedule. One of the strategies is less restrictive in order to avoid unnecessary delays due to uncertainties in execution times. In this case, the generated conditions are evaluated and, if possible, relaxed for operations without a logical connection. For non-nominal execution times, the makespan of the less restrictive control policy is proven to always be better or equal to the makespan of the more restrictive control strategy.