**6. Conclusion and future work**

The underwater domain is a challenging environment in which to maintain the operability of an UUV. Operability can be improved with the embedded adaptation of the mission plan. We implement a system capable of adapting mission plans autonomously in the face of events while during a mission. We do this by using a combination of ontological hierarchical representation of knowledge and adaptive mission plan repair techniques. The advantage of this approach is that it maximises robustness, system performance and response time. The system performance has been demonstrated in simulation. Additionally, the mission adaptation capability is shown during an in-water field trial demonstration. In our fully integrated experiments we achieved the following:

• *Knowledge based framework:* We have presented a semantic-based framework that provides the core architecture for knowledge representation for service oriented agents in UUVs. The framework combines the initial expert orientation and the observations acquired during mission in order to improve the situation awareness in the vehicle. This is currently unavailable in UUVs.

• *Goal-oriented plan vs. waypoint-based plan:* The system uses a goal-oriented approach in which the mission is described in terms of 'what to do' instead of a 'how to do' it. The

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mission is parametrised and executed based on the available knowledge and vehicle capabilities. This is the first time that an approach to goal-based planning is applied to the adaptation of an underwater mission in order to maintain platform's operability.


SAMP is open to event detections coming from other embedded service-oriented agents. We are planning to apply the approach to more complex scenarios involving other embedded agents, such as agents for automatic target recognition. We are also planning to extend it to a team of vehicles performing a collaborative mission. In this scenario, agents are distributed across the different platforms. We are currently working towards a shared situation awareness for a team of vehicles to which every team member possess the awarenessrequired for its responsibilities. The main advantage of our semantic-based approach is the low bandwidth required to share id-coded ontological concepts and, therefore, to cope with the underwater acoustic communication limitations.
