Model-based workcell task planning and control

A framework for the design of a model-based control system for flexible man ufacturing is presented in this paper. The system consists of three basic l ayers: the Task Planning, the Task-Level Programming, and the Simulation la yer. Task planning is based on the description of operations and their prec edence relation. The resulting fundamental plan describes the decomposition of a manufacturing task into an ordered sequence of robot actions. The imp lementation of the plan is carried out using a task-level programming appro ach in which the detailed paths and trajectories, gross and fine motion, gr asping, and sensing instructions, are specified. Plan sequences are verifie d by using a simulation modeling approach based on hierarchical, modular di screte-event system specifications.