Finite-Time Tracking Control of Robotic Systems with Time-Varying Output Constraints

This paper investigates the finite-time-trajectory tracking control of a robotic manipulator subject to time-varying output constraints and unknown lumped disturbances consisting of model uncertainties and external forces. A novel finite-time integral barrier Lyapunov function (FT-IBLF) with an adjustable parameter is constructed. Its barrier property and fractional-power finite-time inequality are established, which ensures that the position tracking error is strictly limited within the preset time-varying constraint boundary. Secondly, a backstepping-based finite-time tracking controller is designed, in which a finite-time disturbance observer is incorporated to estimate the lumped disturbance and compensate for it in a feedforward manner, thereby reducing the dependence on exact model information. Finally, simulations demonstrate that the proposed method can converge the tracking error to the neighborhood of zero within a finite time, and the system state never violates the constraint boundary. The dynamic performance of the system can be flexibly adjusted and optimized by adjusting parameters, which also verifies the effectiveness and superiority of this method.