Class of robust control strategies for robot manipulators with uncertainties

This paper proposes a new class of robust control strategies based on the so-called computed-torque structure for trajectory tracking of robot manipulator with uncertainties. The novelty lies in the design of continuous nonlinear compensator which is based on the lumped nonlinearity and uncertainty of the system. It is shown by theories and simulations that uncertain effects can be eliminated and globally exponential stability, globally asymptotic stability or globally uniform ultimate boundedness stability can be guaranteed. In addition, when the bounds of the lumped uncertainties are unknown, a new adaptive control law is proposed to ensure the globally asymptotic stability in a sense of exponential convergence or globally uniform ultimate boundedness stability.