Cascaded extended state observer based full order sliding mode control strategies for underactuated Flexible Joint Robots

Flexible joint robots (FJRs) can offer several practical advantages over rigid joint robots such as lightweight, low output impedance, safe operations, smooth force transmission, enhanced robustness, better backdrivability, and high energy efficiency. To achieve good results, even in the presence of the system uncertainties and external disturbances in the FJR, we have proposed cascaded extended state observer-based continuous sliding mode control strategies in asymptotic, finite time, and fixed time convergence. Therefore, such methods can be promising tools in controlling and stabilizing different mechanical underactuated systems that can contribute a lot in the service industry, military purposes, medical rehabilitation, and constructions.