A formal model for reactive robot plans

An approach to the representation and analysis of flexible plans, i.e. plans that react to suit the current environment, is described. A formal model has been constructed for building and reasoning about such plans. The model can represent both the plan and the uncertain environment in which the plan is to be carried out. The concept of a flexible plan is demonstrated using a mixed-batch assembly example. A number of examples of uncertain and dynamic environments that can be represented are presented. The author´s, approach is to use a special-purpose model of distributed computation in which plans are hierarchical networks of processes. This model has a rich vocabulary of composition operators for describing plans and world models. The plan analysis techniques are derived from the field of process algebra