Session: Controls 1

Paper Number: 111741

111741 - Disturbance Observer-Based Nonlinear Motion Control of the Parallel Platform for Wave Compensation 

   Offshore installations, such as marine transportation and shipboard cranes, are highly vulnerable to sea conditions, resulting in reduced efficiency and economic losses. To reduce the impact of waves on offshore equipment operations, this paper presents a nonlinear cascade controller for a parallel compensation platform to isolate the load motion from the ship motion. The parallel platform is equipped with multiple hydraulic actuators so that the platform can obtain the advantages of the hydraulic system such as large-power density and large output power. However, dynamic characteristics of the hydraulic system have a non-negligible impact on the performance of the platform. The proposed nonlinear controller considers the kinematic model of this platform and the nonlinear characteristics of the hydraulic system, and consists of a disturbance observer and a sliding mode controller. The disturbance observer accounts for uncertain load force and system parameters separately. In addition, the outer compensation trajectory tracking loop uses sliding mode controller to compensate for the observe error, with desired hydraulic driving force as control output. The inner force control loop is designed through the backstepping method. Finally, Lyapunov-based analysis demonstrates the stability of the closed-loop system, and simulation results verify the effectiveness of the compensation performance in the proposed scheme.

Presenting Author: TianZhu Wang Zhejiang University State Key Laboratory of Fluid Power and Mechatronic Systems

Presenting Author Biography: Tianzhu Wang received the B.Eng. degree in mechanical engineering from Central South University, Changsha, China, in 2020. He is currently working toward the Ph.D. degree in mechatronic engineering with the College of Mechanical Engineering, Zhejiang University, Hangzhou, China.His current research interests include the modeling and control of hydraulic components and electro-hydraulic systems, the sliding-mode control and other nonlinear control in fluid power.