We present TALplanner, a forward-chaining planner based on the use of domaindependent search control knowledge represented as formulas in the Temporal Action Logic (TAL). TAL is a narrative based linear metric time logic used for reasoning about action and change in incompletely specied dynamic environments. TAL is used as the formal semantic basis for TALplanner, where a TAL goal narrative with control formulas is input to TALplanner which then generates a TAL narrative that entails the goal and control formulas. The sequential version of TALplanner is presented. The expressivity of plan operators is then extended to deal with an interesting class of resource types. An algorithm for generating concurrent plans, where operators have varying durations and internal state, is also presented. All versions of TALplanner have been implemented. The potential of these techniques is demonstrated by applying TALplanner to a number of standard planning benchmarks in the literature.

A promising technique used in some planning systems to improve their performance is the use of domain dependent search control knowledge. We present a procedure for compiling search control knowledge, expressed declaratively in a logic, into the preconditions of the plan actions (operators). We do this within the...

Abstract—Mission planning for collaborative Unmanned Aircraft Systems (UAS:s) is a complex topic which involves trade-offs between the degree of centralization or decentralization required, the degree of abstraction in which plans are generated, and the degree to which such plans are distributed among participating UAS:s. In realistic environments such as those found in natural and man-made catastrophes where emergency services personnel are involved, a certain degree of centralization and abstraction is necessary in order for those in charge to understand and eventually sign off on potential plans. It is also quite often the case that unconstrained distribution of actions is inconsistent with the loosely coupled interactions and dependencies which arise between collaborating systems. In this article, we present a new planning algorithm for collaborative UAS:s based on combining ideas from forward chaining planning with partialorder planning leading to a new hybrid partial order forwardchaining (POFC) framework which meets the requirements on centralization, abstraction and distribution we find in realistic emergency services settings. Index Terms—Partial-order planning, unmanned aerial vehicles, planning with control formulas I.