CDF-Based Filter and Fuzzy-Based Adaptive CPFTS Controller for Constrained Underactuated Crane System: Theory and Experiment

This work centers around investigating the fixed-time tracking issue for an underactuated crane system with full-state constraints, disturbance, and measurement noise. A two-module design strategy consisting of state estimation stage and fixed-time tracking control design stage is proposed. Specifically, the composite disturbance filtering (CDF) approach is introduced to estimate states while rejecting and attenuating disturbance. Then by using fuzzy-based variables separation technique and integral barrier Lyapunov function (iBLF), the constrainedly practically fixed-time stability (CPFTS) is implemented to the studied crane system in the second stage. In the end, simulation and experiment results are presented to illustrate the efficacy of the proposed strategy.