Case Study of Digital Twin-based Human-robot Collaborative Work-cell for Satellite Assembly

Satellite assembly has complex structures with both large panels and small connected parts. The adoption of human-robot collaborative assembly (HRCA) can effectively reduce the assembly workloads. As a new assembly mode, HRCA requires deep communication and close collaboration between human and robot, which puts high demands on real-time information acquisition and processing capability. Digital twin, as an emerging technology, points the way to solve the problem. This paper proposes a five-unit human-robot collaborative assembly work-cell framework based on digital twin, where the operation unit, perception & control unit are in physical space and the data unit, model unit, service unit are in virtual space. The functions of all units are described in detail. Taking the satellite assembly as an example, the operation of this framework is discussed and a physical HRCA work cell is constructed based on the digital twin technology. The three important parts of the HRCA processes, task assignment, scene layout and virtual-physical mapping, are elaborated in digital space and physical space.