Dynamic modeling and analysis of multi-flexible-link space manipulators under time-varying dynamic boundary conditions.

• 3D recursive kinematics is introduced for the dynamic modeling of the multi-flexible-link space manipulators. • The general expressions of the dynamic boundary conditions are derived based on 3D recursive kinematics. • The difference between the results of the time-varying modes and time-invariant modes is investigated. This paper presents a dynamic modeling method for the multi-flexible-link space manipulators under time-varying dynamic boundary conditions. This method is based on 3D recursive kinematics and is applicable to the space manipulators with an arbitrary number of flexible links. The elastic deflection of the flexible links is described by using the Assumed Mode Method (AMM). The general expressions of the dynamic boundary conditions are derived by combining the Newton-Euler equation with 3D recursive kinematics. Based on 3D recursive kinematics, the dynamic model suitable for space manipulators with an arbitrary number of flexible links is established. For the multi-flexible-link manipulator systems, the movement of the links will alter the mass distribution of the system, resulting in the time-varying modes of the links. The difference between the results of the time-varying modes and time-invariant modes are investigated. Numerical simulations are performed to verify the adaptability of the proposed dynamic modeling method to different manipulators. Simulation results shows that the results of time-varying modes are in good agreement with those of time-invariant modes, and the simulation calculation time of time-invariant modes is less than that of time-varying modes. For the above reasons, the time-invariant modes are sufficient and it is unnecessary to update the modes. [ABSTRACT FROM AUTHOR]