Prescribed performance tracking control for electro-hydraulic systems with output constraints and valve dynamics compensation
摘要
In this article, we investigate the prescribed performance tracking control problem for electro-hydraulic systems(EHSs) with output constraints and valve dynamic compensation. Firstly, to capture the valve dynamics that can lead to amplitude attenuation and phase lag, as revealed by frequency domain analysis, an appropriate second-order model is employed. Subsequently, a comprehensive fifth-order system model is established to characterize EHSs effectively. Additionally, a low-complexity control scheme, which eliminates the need for computing the time derivative of the intermediate control signals, is integrated to address the “differential explosion” in the backstepping control. Secondly, a modified nonlinear transformation function is employed for EHSs to simultaneously satisfy output and tracking error constraints simultaneously. Furthermore, a global constraint function is introduced to guarantee that EHSs can start arbitrarily within the output constraint boundaries. Finally, the performance of the proposed scheme is demonstrated through simulations and experiments.