Programming robot work flows with a task modeling approach

Programming complex robotic tasks can be very difficult, and is usually carried out by programmers very skilled in different fields, since they have to manage different issues at the same time, e.g., the process design, the task sequencing, and multi-robot programming issues like the collision avoidance and the optimization of the process according to given criteria. A task-oriented programming approach, leaving the programmer design only the process itself and the robotic cell by means of some CAD drawer softwares, makes the programming process simpler and invariant to the skill level of the programmer. The usage of complex models, like the High Level Model previously proposed by the authors, including the notions of task and world at the same time, allows to take into account both the process constraints and the physical ones. Such a model can be exploited to obtain all the feasible work-flows carrying out the required process. The formal description of the proposed work-flow model is provided in this paper, as well as the procedure to build it starting from a given High Level Model. The developed workflow model is suitable for a possible conversion into Petri Nets, as well as for the inclusion in production efficiency frameworks aimed at optimizing the overall process and avoiding possible bottlenecks. A case study is also proposed in order to show how the work-flow model can be built in a realistic, simple but not trivial scenario.