Dual-arm Cooperative Precision Control Method and Experiment for On-orbit Assembly of Space Trusses

A high-precision floating-base dual-arm trajectory tracking control method is proposed to address the dual-arm cooperative precision control challenge in on-orbit assembly of space trusses. An air-floating ground-based microgravity test system is also designed for this application. First，an accurate kinematic and dynamic model is constructed by coupling Lagrange equations with Newtonian constraints. Second，an improved nonlinear model predictive control strategy is developed through integrating a sliding mode variable structure control module into the conventional nonlinear model predictive control framework，which reduces model accuracy dependency while enhancing control precision and robustness. Third，an air-floating microgravity simulation method is employed to establish a dual-arm cooperative precision control test system for on-orbit truss assembly，enabling ground-based microgravity tests for partial truss assembly. Experimental results indicate that the proposed method achieves high-precision control of floating-base dual-arm systems，demonstrating superior end-effector trajectory tracking accuracy compared to conventional nonlinear model predictive control. This research provides theoretical foundation and experimental validation methodology for on-orbit assembly of large space structures.