Anti-disturbance proportional integral attitude control and stabilization of rolling hydraulic position system

Abstract

Disturbance rejection performance for rolling hydraulic position control system has always been a knotty issue. To guarantee the transient performance and improve disturbance rejection performance of the rolling hydraulic position control system, a compound controller, composed of a feedforward controller part based on proportional integral laws and a compensation part based on disturbance observer, is designed and investigated. In this article, a detailed analysis and design principles of the composite controller are provided. Additionally, stability analysis of the controller is proved using Lyapunov function adapted to the system. Finally, a rigorous analysis of the disturbance rejection performance is given with consideration of both instantaneous disturbances and low-frequency disturbances. For single pulse disturbance, the maximum error is reduced from 3.5% to 0.6%. Furthermore, for more complicated disturbance, sinusoidal disturbance is lower than 50 Hz, disturbance rejection performance decreases with increasing frequency and maximum error is reduced from 5.4% to 1.6%. The test results demonstrate that for single pulse disturbance, the maximum error is reduced from 4.12% to 0.64%. Furthermore, for more complicated disturbance, sinusoidal disturbance is lower than 50 Hz, disturbance rejection performance decreases with increasing frequency and maximum error is reduced from 2.71% to 0.70%. Both simulation and experiment results demonstrate that the proposed method possesses a better disturbance rejection performance than the proportional integral method.