Robust adaptive backstepping control for a lower-limb exoskeleton system with model uncertainties and external disturbances

The main purpose of this work is to design a robust adaptive backstepping (RABS) control strategy for pediatric exoskeleton system during passive-assist gait rehabilitation. nonlinear dynamics the have ill-effects uncertain parameters and external interferences. In work, designed applied on assist children 08–12 years, 25–40 kg weight, 115–125 cm height. dynamic model coupled human-exoskeleton established using Euler–Lagrange principle. An appropriate Lyapunov function selected prove uniform boundedness signals. “explosion terms” avoided by establishing virtual law without dynamical parameters. A Microsoft Kinect-LabVIEW experiment carried out estimate desired trajectory. robustness proposed validated varying limb segment masses inducing periodic disturbances. compared with decentralized modified simple adaptive-PD (DMSA-PD) strategy. From simulation results performance improvement index, it observed that RABS outperforms contrast track rehabilitation under effect uncertainties