Modified Higher-Order Sliding Mode Observer-Based Super-Twisting Controller for Perturbed Overhead Cranes

The designs of feedback control and automation systems for overhead cranes require precise information about the crane states. Unfortunately, cranes are usually not equipped with velocity sensors. The current study deals with the problem of finite-time exact states estimation and control of perturbed overhead cranes subject to a dynamic disturbance. To address the state availability problem, a modified higher-order sliding mode observer (HOSMO) is proposed and a HOSMO based second-order super-twisting sliding mode control (STC-HOSMO) is proposed to control the system. Control applications and error analyses based on IAE and ITAE criteria showed the effectiveness of the proposed STC-HOSMO scheme. The results also showed that tracking/regulation and estimation error trajectories asymptotically converged to equilibrium. Additionally, attenuated chattering of the control effort is observed and second-order sliding mode (2-SM) is achieved.