A framework of terminal sliding mode for force/position control of constrained manipulators

Abstract

In this paper, a novel framework of terminal sliding mode is established for force/position control of robotic manipulators whose end-effectors are in contact with constrained surfaces. The framework introduces the terminal sliding mode control concept into both force tracking and position tracking and can serve as a basis for finite-time control study of constrained manipulators. The advantages of the proposed strategy are threefold: 1) the force tracking error and the position tracking error can both converge to zero in finite time; 2) the force convergence rate near the equilibrium and the steady-state force tracking precision are increased in comparison with conventional force tracking control methods; 3) the high gain of conventional force/position tracking control methods is significantly reduced in this method, which is more desirable in industrial applications. Lyapunov stability analysis and simulation study demonstrate the effectiveness of the proposed strategy.