Dynamics modeling and simulation of tethered space robot system

Based on the finite element method, a method with high accuracy and great efficiency is proposed to supply the deficiency of the classical bead model. First, based on nonlinear stress-strain relation, the dynamics model under the orbit coordinate system is derived by using Hamilton principle and C-W Equation. Then, the space tether is accurately discretized by the third-order one-dimensional element. Furthermore, a new efficient time-domain solving algorithm, using the Newmark-β method for estimation and the Newton-Raphson iteration for correction, is proposed. Thus, the goal of quickly and accurately solving the system status is implemented. Compared with the classical lumped mass model results of the proposed algorithm demonstrate that in the case of having similar segment length, the proposed algorithm shows higher accuracy, reduces the time consumption of computation at least 10 times and avoids the pseudo oscillation in tensile stress.