Posture alignment internal force in three-axis actuators based assembly system for large aircraft parts

A kind of posture alignment and joint system for large components of aircraft based on three actuators with 3-axis was studied, and its inverse kinematics as well as dynamic models were established. According to the principle of cooperating kinematics, the properties of redundant actuating were analyzed. Aims at the problem, which the location error of actuators would cause internal forces directly during the process of posture alignment, several methods of controlling the internal forces were presented, i. e. adopting the minimum norm solution of the joins' actuating force and improving the structure of actuators. Finally, a kind of method of relieving internal forces was proposed and its characteristics in application were analyzed. The results of test show that the deformation produced by internal forces is less, which cannot threaten the safety of large aircraft parts. More important, the method of relieving internal forces can work efficiently in the process of assembly, and this will satisfy the need of non-forces joint assembly well in digital system of aircraft assembly.