Tracking control based on proportional resonant controller for electro‐hydraulic systems with input delay.

The growth of marine resources exploitation has led to increased research interest in electro‐hydraulic systems for marine simulation. This study proposes a proportional plus resonant (PR) controller to achieve high tracking performance for electro‐hydraulic systems. Due to the complex structure and non‐linear flow dynamics, establishing accurate mathematical models of electro‐hydraulic systems is challenging. The local linearization technique is applied to simplify the process of model establishment. The system gain is limited by the stability margin due to the input delay, resulting in a phase delay between the real trajectory and the desired reference. To compensate for the phase delay in tracking periodic reference with the traditional proportional and integral controller, a resonant item is added into the controller. The stability analysis of the closed‐loop system is performed using Routh‐Hurwitz criterion. Furthermore, the controller parameters are tuned based on the frequency characteristic to achieve high tracking performance and maintain the adequate stability margin. The effectiveness of the proposed PR controller in tracking periodic references is validated through numerical simulations and practical experiments. [ABSTRACT FROM AUTHOR]