Ambient pressure compensation and robust position control of oil-filled electric joint systems for underwater manipulators
2026-07-27 • Computer Vision and Pattern Recognition
Computer Vision and Pattern Recognition
AI summaryⓘ
The authors studied electric joints used in underwater robot arms, which must handle high water pressure. They looked at how to use oil to balance this pressure but found that oil brings sealing and control problems. They designed a new joint that better seals the oil inside and created a mathematical model that accounts for uncertainties caused by the oil. They also developed a control system to keep the joint stable and tested everything experimentally, showing their approach works.
underwater manipulatorelectric jointpressure compensationoil-filled jointdynamic modelingrobust controlmu-synthesissealinguncertaintyhydraulic system
Authors
Hongrui Wu, Songhui Wang, Xin Wang
Abstract
Electric joint systems are significant elements of an underwater manipulator for its actuation, drive, and control. Working in an underwater environment, the joints suffer huge ambient pressure. To withstand it, the pressure compensation method is usually deployed, whereas the pressurized oil introduces sealing problems as well as parametric uncertainties and unknown disturbances for the dynamic model of the joint. To tackle these issues, this study proposes a design framework for the underwater oil-filled electric joint. The dynamics of the pressure compensation module is analyzed and the structure of the joint is optimized to seal the internal hydraulic oil. An uncertainty dynamic model of the oil-filled joint is established and a robust position controller is designed based on the structured singular value synthesis (mu-synthesis). Experimental results validate the feasibility of the proposed methods.