No abstract

We present a three-level cognitive system in a Learning by Demonstration (LbD) context. The system allows for learning and transfer on the sensorimotor level as well as the planning level. The fundamentally different data structures associated to these two levels are connected by an efficient mid-level representation based on so called "Semantic Event Chains". We describe details of the representations and quantify the effect of the associated learning procedures for each level under different amounts of noise. Moreover, we demonstrate the performance of the overall system by three demonstrations that have been performed at a project review. The described system has a Technical Readiness Level (TRL) of 4, which in an ongoing follow-up project will be raised to TRL 6.

The construction sector is investigating wood as a highly sustainable material for fabrication of architectural elements. Several researchers in the field of construction are currently designing novel timber structures as well as novel solutions for fabricating such structures, i.e. robot technologies which allow for automation of a domain dominated by skilled craftsman. In this paper, we present a framework for closing the loop between the design and robotic assembly of timber structures. On one hand, we illustrate an extended automation process that incorporates learning by demonstration to learn and execute a complex assembly of an interlocking wooden joint. On the other hand, we describe a design case study that builds upon the specificity of this process, to achieve new designs of construction elements, which were previously only possible to be assembled by skilled craftsmen. The paper provides an overview of a process with different levels of focus, from the integration of a digital twin to timber joint design and the robotic assembly execution, to the development of a flexible robotic setup and novel assembly procedures for dealing with the complexity of the designed timber joints. We discuss synergistic results on both robotic and construction design innovation, with an outlook on future developments.

Wood is more and more seen as a sustainable solution to offset carbon emissions from constructions. In response and in parallel to this, the research in robotic timber construction is evolving rapidly, pushed by Industry 4.0 technologies and the integration of digital and physical robotic assets. This paper presents an approach for the design and assembly automation of layered timber structures, with the use of a flexible cell based on collaborative robots. Advanced assembly procedures and digital design of non-standard timber structures are here established and integrated. The automation process is here enhanced by the (1) use of feedback systems based on the location and force signals, (2) the introduction of a flexible robot setup with automatic screwing, and (3) human-collaboration to provide immediate assistance to the robot in the case the signals do not match the defined assembly conditions. The paper discusses the development and use of a Cyber-Physical System to govern the entire construction process, including reflections on the integrated approach to the design, modelling and simulation of the process.