An externally guided spatial augmented reality assembly assistance system in the aviation manufacturing industry

As an augmented reality paradigm, spatial augmented reality (SAR) holds significant application value in assembly operations. However, in the current research, the camera is fixed with the projector, which results in the limited projection angle and poor flexibility. This makes it difficult to be applied in the assembly of cabin-type components in the aviation industry. In this paper, we present an externally-guided spatial augmented reality (EGSAR) system which allows the projector to move freely. First, the proposed system framework, especially the related transformation, is introduced. Under this framework, the implication has been simplified into pose measurement problem. Meanwhile, to track the moving projector, a dodecahedron transfer position target is designed. Due to the EGSAR being a combined system, then, we propose a calibration process for the target, which eliminates the manufacturing errors of the target. Based on the calibrated cameras, projector, and target, the pose measurement problem has been solved. The proposed EGSAR method is experimented in a factory-like scenario, where an operator performs assembly tasks under its guidance. The feasibility and accuracy of the prototype are verified. In conclusion, the proposed EGSAR framework improves the flexibility and can be a valid solution to extend the uses of the SAR system.