Specification and synthesis of plans using the features and fluents framework

Abstract: An autonomous agent operating in a dynamical environment will face a number of different reasoning problems, one of which is how to plan its actions in order to pursue its goals. For this purpose, it is important that the agent represents its knowledge about the world in a coherent, expressive and well-understood way, in our case the temporal logics from Erik Sandewall's ”Features and Fluents” framework.However, most existing planning systems make no use of temporal logics, but have specialised representations such as the STRIPS formalism and hierarchical task networks. In order to benefit from the techniques used by these planners, it is useful to analyse and reconstruct them within the given framework. This includes making explicit the ontological and epistemological assumptions underlying the planners; representing plans as entities of the temporal logic; and reconstructing the algorithms in terms of the new representation.In this thesis, a number of traditional planners are analysed and reconstructed in this way. The total-order planner STRIPS, the partial-order planner TWEAK, the causal-link planner SNLP, and finally the decompositional planner NONLIN are all examined. The results include reconstructions of the planners mentioned, operating on a temporal logic representation, and truth criteria for total-order and partial-order plans. There is also a discussion regarding the limitations of traditional planners from the perspective of ”Features and Fluents”, and how these limitations can be overcome.