Does your Robot have Skills?

This article presents a unifying terminology for task-level programming of highly flexible mobile manipulators in industrial environments. With a terminology of tasks and object-centered skills, industrial applications are analyzed in the logistic and assistive domains. The analysis shows that many tasks can actually be solved with a small library of predefined building blocks, called skills. In logistics domains, it can be exploited that the sequences of skills needed to solve specific tasks follow certain patterns, whereas in assistive tasks, the sequence vary a lot, and tasks must be taught to the robot by a user, based on Standard Operating Procedures or process knowledge. An overview is presented on how to implement a skill-based architecture, enabling reuse of skills for different industrial applications, programmed by shopfloor workers. The terminology of tasks, skills, and motion primitives is introduced and designed to separate responsibilities of robot system developers, robot system integrators and shop floor users concerning programming of the robot system. The concept of testable pre- and postconditions assigned to the skills are proposed to help both in developing skills and asserting when a skill is applicable.