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Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

Study on the Motion Stability of the Autonomous Underwater Helicopter
Jin Guo1, Yuan Lin1, 3, *, Haocai Huang1, 2, 3, 4
1. Institute of Ocean Engineering and Technology, Ocean College, Zhejiang University, Zhoushan, Zhejiang, China;
2. Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong, China;
3. Hainan Institute, Zhejiang University, Sanya, Hainan, China;
4. Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province, Zhejiang University, Zhoushan, Zhejiang, China.
*Corresponding author: Yuan Lin.
fins (Wang et al., 2019), can achieve horizontal translation and rotation
through four horizontally arranged propellers, and can achieve fixedheight and depth movement and control of the angle of attack throughtwo vertically arranged propellers. AUH can carry various sensors tosurvey a large area of sea like AUV, and can also perform high-mobilityunderwater tasks like ROV. Fig. 1 (b) is the simplified model used in thesimulation, and its basic parameters are shown in the Table 1.

ABSTRACTThe hydrodynamic performance of a novel hovering autonomous
underwater vehicle, the autonomous underwater helicopter (AUH) isinvestigated by means of computational fluid dynamics with theadoption of overlapping mesh method. Based on the numericalsimulation of the plane motion mechanism test (PMM), thehydrodynamic coefficients of AUH (HG1_load) are solved according tothe derived spatial motion equation. According to Routh’s stability
criterion, the horizontal movement and vertical movement stability
1.0, 𝐺17.2 ) are obtained, which further
indexes of AUH ( 𝐺show that the AUH has better vertical movement stability than thetorpedo-shaped AUV.

KEY WORDS: Autonomous underwater vehicle (AUV);
computational fluid dynamics (CFD); motion stability; hydrodynamics
INTRODUCTION
The submarine mobile observation platform composed of Autonomous
Underwater Vehicle (AUV), Remote Operated Vehicle (ROV),
Autonomous Underwater Glider (AUG), and Human Occupied Vehicle(HOV) can quickly respond to emergencies in the target sea area, making
the submarine observation network more comprehensive andstereoscopic (Zhu et al., 2017; Fenghua et al., 2019). Due to thelimitations of umbilical and the impact of surface waves on the mothership, ROVs are only able to detect local sea areas for a short period oftime (Chen et al., 2021; Lubis, Kimiaei and Efthymiou, 2021). HOVs,
such as Alvin (Netburn et al., 2018), Deep Sea Warrior (Wu et al., 2018),
Endeavor (Liu et al., 2021), etc., can effectively perform various marine
scientific expedition missions on complex seabed such as seamounts,ridges, basins and hydrothermal vents, but Due to limited energy supply,high manufacturing and maintenance costs, it has not been widely used.
AUV and AUG, such as HUGIN, REMUS, Seaglider, Slocum, etc.
(Allen et al., 1997; Hagen, Storkersen and Vestgard, 1999; Eriksen et al.,
2001; Webb, Simonetti and Jones, 2001), can be equipped with a varietyof sensors to continuously collect environmental parameters in a wide
range of underwater, but the traditional torpedo shape is poor inmaneuverability and the characteristics of AUG zigzag navigation makethis type of underwater vehicle unable to perform detection close tocomplex terrain task.
As shown in Fig. 1, AUH, as a new type of underwater vehicle withoutFigure 1. (a) AUH during a trial in the lake, and (b) simplified model insimulation.
Table 1. Basic parameters of the current AUH.

Parameter
Value

Diameter(𝑚𝑚)
1557

Height(𝑚𝑚)801

Weight(𝑘𝑔)300

Cruise Speed(𝑚/𝑠)2

The research on AUH hydrodynamics mainly relies on the numericalsimulation of CFD calculation software, like the motion stability,
water‑entry impact force, Magnus force, water entry impact forces andhydrodynamic-interaction of AUH (Chen et al., 2017; Chen and Lu,
2019; Chen, Chen and Cai, 2019). In the study of the AUH basic model,
Lin found that the eddy current and secondary flow at the tail of thecomplete dish-shaped AUH will cause its hydrodynamic fluctuations(Lin et al., 2021), and the local adjustment of the tail shape is beneficial
to improve the hydrodynamic performance of the AUH (Lin et al., 2022).
In this paper, on the basis of the basic model, the influence of the cabin

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