Delay compensation based controller for rotary electrohydraulic servo system

Abstract The typical power-assisted hip exoskeleton utilizes rotary electrohydraulic actuator to carry out strength augmentation required by many tasks such as running, lifting loads and climbing up. Nevertheless, it is difficult precisely control due the inherent nonlinearity large dead time occurring in output. presence of fires undesired fluctuation system Furthermore, risk damaging mechanical parts increases these high-frequency underdamped oscillations surpass natural frequency system. In addition, closed-loop performance degraded stability unenviably affected. this work, a Sliding Mode Controller enhanced Smith predictor (SMC-SP) scheme that counts for output delay parameter nonlinearities presented. SMC utilized its robustness against uncertainty servo parameters whereas alleviates system’s states. Experimental results show smoother response proposed regardless amount existing time. trajectories SMC-SP versus other methods were compared different predefined