Hyperbolic-Secant-Function-Based Fast Sliding Mode Control for Pantograph Robots

Abstract

Technological advancements in control systems are indispensable and require a robust controller with fast convergence in numerous sectors like robotics, space engineering, etc. A sliding mode controller (SMC) is a robust controller when subjected to nonlinearities, external disturbances, and uncertainties in system dynamics. However, SMC is prone to chattering, which can damage the plant in long term and results in low tracking accuracy. In this research paper, a novel hyperbolic secant function (HSF)-based SMC is proposed that achieves fast convergence, reduces chattering, and improves tracking performance. Stability analysis is conducted based on Lyapunov stability criteria. Comparative simulations and experiments on a pantograph robot (PR) show the effectiveness of the proposed algorithm.