Geometry and Force-Informed Robotic Assembly with Small Relative Initial Deviations for Circular Electrical Connectors

Circular electrical connectors (CECs) have a wide range of applications in scenarios that require reliable connections. However, sockets are often located in narrow scenes with random spatial orientations, complex lighting conditions, and obstructions from cables, making it difficult to accurately locate them through cameras. Besides, due to the complex geometric structure of CECs and the presence of electrode protection slots, the existing research on the assembly of cylindrical or polygonal pegs and holes may not be applicable to the assembly of such components. To this end, this article proposes a novel robotic assembly strategy for CECs with small relative initial deviations, whose core is to design a search trajectory and heuristic force strategy to perceive force/pose (F/P) discontinuity characteristics under different geometric constraints. This assembly strategy is independent of the CEC's size and is not affected by the socket's spatial orientation. The experiments with two different sizes of CECs on a robot equipped with a 6-dimensional force/torque ($\mathbf{F} / \mathbf{T}$) sensor are conducted, and the effectiveness and robustness of the proposed assembly strategy for CECs are demonstrated.