Physically distributed multi-robot coordination and collaboration in construction: A case study in long span coreless filament winding for fiber composites

This paper presents strategies for the scalable fabrication of long-span composite structures made possible through physically distributed heterogeneous multi-robot collaboration. An interactive and collaborative fiber laying process between industrial robots and an unmanned aerial vehicle (UAV) is described as a case study, investigating the challenges of multi-robot distributed fabrication, but also the design and system potentials of such an approach. A proof-of-concept interactive and collaborative process based on hardware exchange was developed for the process of long-span fiber composite filament winding. Components of the fabrication workcell, including two high pay-load industrial six-axis robots, a custom developed UAV drone, pneumatic winding end-effectors with sensor integration, and a signal integrated mechanism for tension control are described. This paper covers particularly the hardware and software components and strategies that coordinated a physically distributed collaborative process between the diverse system of devices, robots, and sensor integrated machines. These aspects include: (1) a platform-agnostic communication infrastructure based on ROS (2) compilation of coordinated and sequence dependent fabrication instructions from the design environment into a custom task list for execution in a web user interface (3) an adaptive and flexible strategy for enabling the flexible execution of industrial robot control code (4) hardware strategies and sensors for handling process tolerances emerging from physically distributed collaboration. The paper concludes with an outlook on important considerations and technical components for increasing the scale and complexity of fabrication through digital coordination and physically distributed collaboration.