Underwater gliders, which glide through water columns by use of a pair of wings, are efficient long-distance, long-duration marine environment observatory platforms. The Sea-Wing underwater glider, developed by the Shenyang Institute of Automation, CAS, is designed for the application of deep-sea environment variables observation. The system components, the mechanical design, and the control system design of the Sea-Wing underwater glider are described in this paper. The pitch and roll adjusting models are derived based on the mechanical design, and the adjusting capabilities for the pitch and roll are analyzed according to the models. Field experiments have been carried out for validating the gliding motion and the ability of measuring ocean environment variables. Experimental results of the motion performances of the glider are presented.
An intensive field observation experiment using 12 Chinese gliders equipped with conductivity-temperature-depth (CTD) sensors and 62 expendable CTD probes (XCTDs) was performed to investigate the 3-D structure and time evolution of an anticyclonic eddy in the northern South China Sea (NSCS). The observed results showed that the anticyclonic eddy had a horizontal radius of about 80 km at surface and a vertical depth of impact of more than 1000 m. The largest temperature and salinity anomalies compared with the averaged values of the temperature and salinity profiles were 3.5°C and 0.4 psu at 120 m depth, respectively. Combined analysis of altimeter sea level and water mass properties indicated that the anticyclonic eddy was shed from the Kuroshio loop current. The vertical axis of the anticyclonic eddy tilted from surface to the observed maximum depth (1000 m) along its translation direction against the 2000 m isobath. The center of the anticyclonic eddy remained in the region east of Dongsha Island for more than half a month. During this time, the long axis direction of the eddy changed from across the slope to along the slope. Then, the eddy moved southward along the 2000 m isobaths. Both the geostrophic current and temperature distribution revealed that the eddy intensity weakened during the observation period gradually. These observations indicated strong interaction between the anticyclonic eddy and the slope topography of Dongsha Island.
Multibody marine robots, representing a promising research and development area, have gained acute attention and response from civil and military fields. A multibody marine robot is a multibody system composed of multiple single-body marine robots (defined as a unit) in a certain topology. Such a system is generally characterized by underactuation, hyperredundancy, power distribution, modularization and so on. Compared with traditional single-body marine robots, multibody marine robots can carry greater loads and have more forms of motion, so they can meet more specialized functional requirements. At the same time, they also have more complex hydrodynamic characteristics due to their unique structures and motion forms. In this paper, the types, features, and hydrodynamic characteristics of typical multibody marine robots are reviewedreviewed reviewed reviewed and summarized based on the connection structures between units. In addition, the development trends of multibody marine robots are analyzed and discussed. This review work anticipates positive attention from future readers regarding multibody marine robots, which represent an important subarea of marine robots.