PRACE (the Productive Robot ApprentiCE)

PRACE—The Productive Robot Apprentice. Project funded under the European Union’s Seventh Framework Programme (FP7), (Ref. NMP-ICT-FoF 285380 PRACE), 2011-2014, [Budget M€4.819, EC Contribution M€3.390];

Researchers: Rolf Johansson, Anders Robertsson, Mahdi Ghazaei

Project Leader: Rolf Johansson

The objective of PRACE is the development of a highly adaptable two handed, mobile robot system for automation of typical small batch assembly operations. An important key feature is the fast and intuitive training of the PRACE system.

Driven by the trend to a more and more customer specific production the boundary conditions for assembly automation have changed significantly. As the systems available on the market cannot cover this extreme flexibility towards weekly changing applications a new robot system concept will be developed within PRACE. An important requirement is the ability to train the robot system with worker skill fast and intuitive.

The PRACE concept basically relies on robot learning by demonstration. We compare the robot learning to a master-apprentice-relation-ship. There, a master teaches an apprentice by instructing certain skills by demonstration. The apprentice watches the actions and effects to categorize this newly gathered knowledge into his knowledge base. Then, while applying this new skill, the master corrects the execution by refining the experience. This loop is iterated until the master is satisfied with the result.

Another important aspect of the PRACE robot system is the operation without safeguards to reach the target of fast setup times. Operation without safeguards however limits the maximum robot velocity. To remain competitive with the human worker a dual-armed robot approach is followed to reach a similar working output as the human worker by modest robot velocities.

With the combination of dual-armed manipulation and a mobile platform to provide local mobility within the working place basically new application tasks may be now automated economically by this new system approach. Using a modular approach the PRACE system can even be recombined to use only parts of the robot system for dedicated applications, i.e. using only a single arm or using the system without mobility.

Different assembly use cases are defined as test environment of the PRACE concept. At end of the project an evaluation phase in real production environment is planned to test the functionality of the system and to ensure the ability to train the system by non-expert users within half a day.