A novel peg-in-hole approach based on geometrical analysis for inclined uncertainty

In the industrial manufacturing processing, peg-in-hole assembly is the core technique for automation, which usually involves two stages. The first stage is the search phase, which is used to find the center of the hole. Then, the peg is aligned with the hole on the plane in the second stage, known as the insertion phase. However, the slight orientational misalignment between peg and hole makes the geometrical analysis of the peg-in-hole assembly process inaccurate. The peg would be stuck because of orientation errors. To deal with this issue, we present a strategy with a standard process to obtain both the location and orientation information in one stage. Compared with the general blind search approaches, the combination of the two targets can improve the efficiency and robustness for the task. The experiments are tested with a cylindrical peg, which is 6 millimeters in diameter, and the hole having a clearance of H7/g6, which means the maximum clearance is about 30 µm.