Prescribed performance fixed-time tracking control based on extended state observer for dual-arm space robot with disturbances

This paper investigates the fixed-time trajectory tracking control problem for dual-arm space robots (DASRs), accounting for transient performance constraints and external disturbances. To suppress the overshoot and improve convergence speed of the trajectory tracking errors, prescribed performance control (PPC) method is studied to convert the tracking errors into unconstrained variables. Meanwhile, to attenuate the chattering in control torque, a fixed-time extended state observer (FxTESO) is suggested to estimate the unknown external disturbances. A nonsingular fast terminal sliding mode surface (NFTSMS) is designed and subsequently employed in devising a robust adaptive trajectory tracking controller. The tracking errors of the DASR are proved to consistently remain within the predefined bounds and converge to an arbitrarily small vicinity around the origin within fixed time. Numerical simulations are conducted to demonstrate the efficacy of the proposed approach.