Abstract
Cardiovascular diseases often necessitate implantable therapies such as mechanical circulatory support devices, which are evaluated using mock circulatory systems. This study presents two nonlinear control strategies—classical backstepping and command-filtered backstepping for regulating the hydraulic dynamics of a hybrid pneumo-hydraulic mock circuit. After introducing the design steps of the two controllers, the closed-loop stability analyses are presented in the context of Lyapunov theory. To show the effectiveness of the two controllers, some simulations are performed by also evaluating in terms of tracking error and robustness to measurement noise, and command-filtered backstepping provides the best balance of performance and efficiency for precise, safe device testing.