A primary–secondary admittance control strategy for dual-Stewart platforms in confined-space aircraft component alignment

Aircraft assembly is a critical phase in the manufacturing process, where the accuracy and efficiency heavily rely on the performance of posture adjustment mechanisms. For components with point features and linear features, traditional multi-point adjustment technologies based on numerical control positioners are limited by spatial constraints, heavy equipment, and high costs. This paper addresses the challenges of posture adjustment for point-feature and linear-feature aircraft components in confined spaces during assembly (e.g., wing fuselage assembly). We propose a cooperative control strategy using dual-Stewart platforms as core executive units. The approach integrates robust position control with admittance-based force–position coordination to achieve high-precision posture adjustment and internal force–moment suppression. We demonstrate that the system achieves a positioning accuracy of within ±0.05 mm in translation and ±0.05° in orientation through a comprehensive dynamics simulation, with an internal force–moment suppression rate exceeding 90.03 %. The results validate the effectiveness of the method for enhancing flexibility and reliability in aircraft assembly.