In order to implement real-time positioning and tracking of the pose of the closed-loop dual-arm space robot body,the recursive Newton-Euler kinematic equations on screw form are derived,and,according to the conservation laws of linear and angular momentum of the free-floating space robots,the dynamic equations of the closedloop system of the free-floating dual-arm space robots are set up based on the theory of spatial operator algebra. Then,the decomposition and inversion of the generalized mass matrix are achieved by means of the sequential filtering and smoothing methods of optimal estimation theory,with the high-efficiency computation for O( n) times. Finally,the closed-loop system with manipulators of 2 planes and 3 degree of freedom is simulated by using Mathematica 6.0,and the results are compared with those of the ADAMS. It is found that the proposed method based on spatial operator algebra is correct and efficient and that it can be applied to the real-time dynamic simulation of spatial
complex multi-body systems as well as the modeling analysis of control systems.