2.3 Hierarchical activity analysis
The activity analysis method of the CDM is a systematic procedure to produce refined user requirements suitable for further system and subsystem analysis. From the analysis of the process to be automated, a hierarchical description of robot system activities to be performed is obtained. The CDM proposes a three-layer hierarchy of
activities:
• The very top level, robotic missious, represents the highest level of activity for which a robot system is responsible (e.g. "SERVICE a life science experiment", "REPAIR a satellite").
• Each mission can be decomposed into tasks, defined as the highest level of activity performed on a single subject (e.g., "OPEN a door", "INSTALL a sample in a processing furnace", "POLISH a surface", "WELD a seam").
• Finally, each task can be decomposed into actions (e.g., "GRIP a sample container", "DISPLACE tool to a position", "MOVE the container to the freezer", "INSERT the container in the port", "SLIDE a drawer", "RUB along a path on a surface", "FOLLOW a seam", "TRACK a part on a conveyor").
For each action, a realization with a particular control concept can be established (e.g., free continuous path control for MOVE, or impedance control for INSERT and SLIDE) such that there are well-defined criteria for identifying actions within a task.
The CDM offers a "catalog" of frequently occurring tasks and actions, together with templates on which action attributes should be defined. As an example, a template for the RUB action in a polishing application is reported in Section 3.
2.4 Functional requirements analysis
For control system requirements analysis, the key concept is to start with a purely functional analysis. Nor It Even the most perse applications use the same fundamental control functions, but in possibly quite different realizations.
The control functions are cast in the same overall structure as the activities, namely a three-layer hierarchy responsible for achieving robot missions, tasks, and actions, and a general framework (logical model) for robot control functions, called the functional reference model (FRM) is defined. The top-level view of the FRM is shown in Fig. 2.