Practical Prescribed-Time Fully Actuated Tracking Control for 2-DOF Pneumatic Parallel Mechanism With Input Saturation.

Abstract

In this article, the attitude tracking control is investigated for a two-degree-of-freedom (2-DOF) pneumatic parallel mechanism subject to input saturation and unknown disturbances. First, joint estimation of unknown dynamics and disturbances is achieved by integrating a radial basis function (RBF) neural network into the design of a prescribed-time refined extended state observer (PTRESO). Next, a second-order auxiliary system is constructed to mitigate the effects of input saturation. A practical prescribed-time fully actuated control (PPTFAC) method is developed to simplify controller design and ensure that the tracking error reaches a preset accuracy within a prescribed settling time. Finally, the effectiveness and robustness of the proposed method are validated through simulations and experiments.