Dynamic modeling and motion control strategy for deep-sea hybrid-driven underwater gliders considering hull deformation and seawater density variation. (1st October 2017)

• Record Type: Journal Article
• Authors: Yang, Yanpeng; Liu, Yuhong; Wang, Yanhui; Zhang, Hongwei; Zhang, Lianhong
• Is Part Of: Ocean engineering. Volume 143(2017)
• Page Start: 66
• Page End: 78
• Publication Date: 2017-10-01
• Subjects: Deep-sea hybrid-driven underwater glider -- Dynamic modeling -- Hull deformation -- Depth-varying seawater density -- Motion control strategy; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2017.07.047
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Operating in the depth-varying oceanic environment, the buoyancy of deep-sea underwater gliders (UGs) will change with depth due to pressure hull deformation and seawater density variation. As the buoyancy variation caused by these two factors is of the same order of magnitude as the nominal net buoyancy, hull deformation and seawater density variation will accordingly affect the dynamic behaviors of deep-sea UGs. In this paper, a full dynamic model was established using Newton-Euler method for a deep-sea UG, PETREL-II. The hull deformation and seawater density variation, fitted as the functions of depth, are considered in the model. Comparisons of results obtained by sea trials, the full dynamic model and the simpler dynamic model without considering hull deformation and seawater density variation showed that the proposed full dynamic model can more truly reflect dynamic behaviors of the glider. Comparisons of simulation results for the full and simpler dynamic models showed hull deformation and seawater density variation have great effect on pitch angle and velocity of the gliders. Through analysis of motion control strategy, a buoyancy compensation scheme was proposed to reduce the negative effect of hull deformation and seawater density variation, and was validated to be effective by sea trials. Highlights: The mathematical model of buoyancy variation of the hull is established. A full dynamic model for gliders is proposed considering hull deformation and seawater density variation. The full dynamic model is verified to be more precise than the simpler model by sea trials. Motion behaviors of a glider in three common motions are predicted using the full dynamic model. A buoyancy compensation scheme in motion control strategy is proposed by using bladder and moving mass.