Fast terminal sliding mode control based on speed and disturbance estimation for an active suspension gravity compensation system

Abstract In this paper, a fast terminal sliding mode controller is designed for an active suspension gravity compensation system with unknown bounds of uncertainties and disturbances. A robust finite-time convergence estimator is used to estimate the velocity and the disturbances. The estimator can guarantee that the speed of the estimation errors converge faster than the displacement tracking errors by regulating its gains. The corresponding stability and robustness of the closed-loop system are proved. In particular, the proposed control scheme can reduce the chattering effectively and render the high-precision tracking performance that have been verified by the simulation and experiments.