Abstract: The fatigue test of the flap and slat movement mechanism of a project adopts a large-retreat three-segment (front flap, main flap, and rear flap) Fowler flap structure. The wing surface movement, as the spatial composite movement consisting of translation and rotation, are characterized by multiple overlapping areas, large changes in deflection rate, and large differences in profile trajectories, making it difficult to simultaneously and accurately apply alternating loads that are always perpendicular to the airfoil during the movement of the airfoil. In this paper, a set of follow-up loading system for the lift structure with spatial complex movement is developed for the first time, including multiple control systems for wing surface deflection, follow-up mechanism and coordinated loading, involving multiple control parameters such as angle, displacement, load, speed, etc. The multi-system and multi-parameter coupling synchronous control technology is used to achieve autonomous control of wing surface deflection and precise application of wing surface alternating loads, ensuring real-time coordination and synchronization of the direction, load, and deflection angle of the actuator cylinder at the loading point of the wing surface. Follow-up loading is thus achieved in the entire process of wing surface deflection. The test results show that the dynamic error of the load during the movement of the airfoil is less than 3%, and the follow-up loading system is feasible and effective.

Key words: motion mechanism, movable airfoil, follow-up loading, synchronous loading, coupling control