Towards Robust Execution of Mission Plans for Planetary Rovers

The paper discusses an on-line control architecture for plan execution whose main aim is to prevent (at least in some cases) the occurrence of action failures. To reach this result, the plan to be executed has been enriched with additional knowledge about the intermediate conditions (i.e., invariant conditions), which must be satisfied during the execution of (durative) actions. This knowledge is used by a Temporal Reasoner to detect anomalous situations that may endanger the safeness of the plan executor. Whenever an anomaly has been detected, the proposed control architecture tries to prevent a failure by changing the execution modality of the action while it is still in progress. Preliminary experimental results, obtained in a simulated space exploration scenario, are reported.