Loop shaping-based robust controlin hydraulic servo system

The swing bench of anti-rolling tanks is a hydraulic servo system achieving position following control, and aims to simulate ship motion. When the bench moves, there is inter-coupling between the two freedoms of rolling and swaying. The sloshing fluid in the tank could generate large disturbing force and torque, which lead to parameter uncertainty in system modeling. These factors will greatly affect the system´s precision. The decoupling controlling is achieved by building a coupling motion model for swing benches, then loop shaping control strategy is introduced into controller designing. The simulations show that this system can accurately and rapidly follow up the dynamically inputted rolling and swaying displacement signals, achieve estimation and compensation of disturbance, improve the system´s following speed and robustness, and more accurately validate the anti-rolling tank´s performance. The method provides effective solutions for similar hydraulic servo systems in other fields.