Free-floating flexible space robot trajectory tracking

The problem of trajectory tracking of a two-link free-floating flexible space robot is concerned in this paper. The dynamic equations of the robot are firstly developed by using Lagrange's principle with elastic vibration, and then they are transformed into a fully controllable form with the flexible vibration disturbance for the purpose of controller synthesis. By this simplified model, a robust control approach using adaptive non-singular terminal sliding mode is developed, in which the dynamic uncertainty and disturbance can be eliminated via the online updating law, and the associated Lyapunov stability analysis are also investigated. Numerical simulation results show that the sliding mode is modified by adding a conditional integral to reduce the stable error in the present of attitude disturbance of a spacecraft.