Modelling and Fast Terminal Sliding Mode Control for Mirror-based Pointing Systems
This work addresses control challenges for mirror-based pointing systems, likely in applications like optics or robotics, but appears incremental as it builds on existing sliding mode methods with modifications.
The paper tackles the control problem for mirror-based pointing systems by proposing a new discrete-time Fast Terminal Sliding Mode controller, which shows advantages over Terminal Sliding Mode and Model Predictive Control in simulations and real-time experiments.
In this paper, we present a new discrete-time Fast Terminal Sliding Mode (FTSM) controller for mirror-based pointing systems. We first derive the decoupled model of those systems and then estimate the parameters using a nonlinear least-square identification method. Based on the derived model, we design a FTSM sliding manifold in the continuous domain. We then exploit the Euler discretization on the designed FTSM sliding surfaces to synthesize a discrete-time controller. Furthermore, we improve the transient dynamics of the sliding surface by adding a linear term. Finally, we prove the stability of the proposed controller based on the Sarpturk reaching condition. Extensive simulations, followed by comparisons with the Terminal Sliding Mode (TSM) and Model Predictive Control (MPC) have been carried out to evaluate the effectiveness of the proposed approach. A comparative study with data obtained from a real-time experiment was also conducted. The results indicate the advantage of the proposed method over the other techniques.