Modified Dual Hierarchical Terminal Sliding Mode Control Design for Two-Wheeled Self-Balancing Robot

A modified dual hierarchical terminal sliding mode control (MDHTSMC) strategy is developed in this study for the control of a two-wheeled self-balancing robot (TWSBR). The control framework incorporates individually designed sliding surfaces within a structured dual-layer hierarchy, enabling explicit prediction of convergence time. To overcome the system’s underactuation characteristics, a hierarchical structure is embedded into the dual terminal sliding mode control law. Additionally, the proposed approach mitigates the chattering effect and enhances the system’s selfbalancing capabilities. Numerical simulations are conducted to verify the controller’s effectiveness and to confirm the theoretical results.