Submit to Machines Review for Machines Propose a Special Issue

Journal Menu

Journal Browser

Advances in Underwater Robot Technology

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Machines (ISSN 2075-1702). This special issue belongs to the section "Robotics, Mechatronics and Intelligent Machines".

Deadline for manuscript submissions: closed (15 August 2022) | Viewed by 23885

Share This Special Issue

Special Issue Editors

Dr. Liwei Shi

E-Mail Website
Guest Editor

Key Laboratory of Convergence Medical Engineering System and Healthcare Technology, The Ministry of Industry and Information Technology, Beijing Institute of Technology, Beijing 100081, China
Interests: under water robots; biologically inspired robots; medical robots; soft robots

Prof. Dr. Dongming Gan

E-Mail Website
Guest Editor

School of Engineering Technology, Purdue University, West Lafayette, IN 47907, USA
Interests: robotics; mechanism and machine theory; design; modeling; control and development of intelligent reconfigurable robotic systems; compliant robot manipulators; flexible light-weight wearable devices; health care and domestic human-robot co-existing scenarios

Prof. Dr. Zhibin Song

E-Mail Website
Guest Editor

Center for Advanced Mechanics and Robotics, School of Mechanical Engineering, Tianjin University, Tianjin 300354, China
Interests: reconfigurable mechanism; motion structure; continuum robot; rehabilitation robot

Dr. Huiming Xing

E-Mail Website
Guest Editor

College of Intelligent Systems Science and Engineering, Harbin Engineering University, Harbin 150001, China
Interests: underwater robot; bio-inspired robot
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

With the rapid development of scientific ocean exploration, underwater robots have become one of the most important tools for exploiting and utilizing marine resources. When compared with autonomous underwater vehicles (AUVs), the core feature of bionic small-scale robots refers to the capability to operate missions such as tracking ocean creatures and the ability of monitor the marine environment in narrow underwater spaces. Therefore, these small-scale biomimetic robots have been receiving increasing interest from academia.

It is clear that bioinspired methods are becoming increasingly important in the face of the complexity of today’s demanding applications. Biological inspiration in underwater robotics is leading to complex structures with sensory–motor coordination, in which learning often plays an important role in achieving adaptation.

This Special Issue will focus on the theoretical and technological challenges of evolutionary transformation from biological systems to intelligent underwater robots. All aspects of underwater robotics and biologically inspired robots are welcome.

Prof. Dr. Liwei Shi
Prof. Dr. Dongming Gan
Prof. Dr. Zhibin Song
Dr. Huiming Xing
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Machines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

underwater robots
biomimetics and biologically inspired robots
automation, control systems, simulation techniques, and control applications
sensor design, multisensor data fusion, and wireless sensor networks
computer vision and image processing
MEMS, nanotechnology, NEMS, and micro/nanosystems
multirobot systems and distributed robotics

Published Papers (10 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

27 pages, 4304 KiB

Open AccessArticle

A Vision-Based Underwater Formation Control System Design and Implementation on Small Underwater Spherical Robots

by Pengxiao Bao, Liwei Shi, Zhan Chen and Shuxiang Guo

Machines 2022, 10(10), 877; https://doi.org/10.3390/machines10100877 - 28 Sep 2022

Cited by 3 | Viewed by 1905

Abstract

The ocean is a significant strategic resource, and the insufficient development and use of the ocean, as well as the increase in attention to the ocean, have led to the development of underwater robot technology. The need for in-depth marine exploration and the limitations of one underwater robot has sparked research on the underwater multi-robot system. In the underwater environment, weak communication is caused by the shielding effect of the seawater medium, which makes multi-robot systems difficult to form. Hence, we combine the robot’s vision system with the leader-follower structure to form a vision-based underwater formation method, in which the visual solution serves as the control system’s feedback. By using three small underwater robot platforms, the proposed method is proved to be effective and practicable through underwater formation experiments. Furthermore, the coordination period and error of the control system are analyzed. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

20 pages, 9953 KiB

Open AccessArticle

Hydrodynamic Characteristic-Based Adaptive Model Predictive Control for the Spherical Underwater Robot under Ocean Current Disturbance

by Ao Li, Shuxiang Guo, Meng Liu and He Yin

Machines 2022, 10(9), 798; https://doi.org/10.3390/machines10090798 - 10 Sep 2022

Cited by 6 | Viewed by 1839

Abstract

In the navigation of underwater robots, large ocean current disturbance often causes significant tracking errors. To better resist ocean current disturbance, the hydrodynamic characteristics of the spherical underwater robot are studied, and a model predictive control strategy based on adaptive model parameters is proposed, according to these characteristics. Firstly, the hydrodynamic characteristics of the robot under static water and constant flow disturbance were obtained and analyzed by the computational fluid dynamics method. Then, the dynamic models of the robot under different disturbances could be calculated from the data obtained, based on the least square method. Finally, an adaptive model predictive control (AMPC) strategy, with an ocean current observer, was designed, based on the dynamic models. When the current disturbance velocity was twice the robot velocity, the proposed strategy reduced the tracking error by 39% and 42% in X and Y directions, respectively. In addition, the hydrodynamic characteristics were verified by experiments. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

13 pages, 1969 KiB

Open AccessArticle

ULO: An Underwater Light-Weight Object Detector for Edge Computing

by Lin Wang, Xiufen Ye, Shunli Wang and Peng Li

Machines 2022, 10(8), 629; https://doi.org/10.3390/machines10080629 - 29 Jul 2022

Cited by 4 | Viewed by 2085

Abstract

Recent studies on underwater object detection have progressed with the development of deep-learning methods. Generally, the model performance increase is accompanied by an increase in computation. However, a significant fraction of remotely operated underwater vehicles (ROVs) and autonomous underwater vehicles (AUVs) operate in environments with limited power and computation resources, making large models inapplicable. In this paper, we propose a fast and compact object detector—namely, the Underwater Light-weight Object detector (ULO)—for several marine products, such as scallops, starfish, echinus, and holothurians. ULO achieves comparable results to YOLO-v3 with less than 7% of its computation. ULO is modified based on the YOLO Nano architecture, and some modern architectures are used to optimize it, such as the Ghost module and decoupled head design in detection. We propose an adaptive pre-processing module for the image degradation problem that is common in underwater images. The module is lightweight and simple to use, and ablation experiments verify its effectiveness. Moreover, ULO Tiny, a lite version of ULO, is proposed to achieve further computation reduction. Furthermore, we optimize the annotations of the URPC2019 dataset, and the modified annotations are more accurate in localization and classification. The refined annotations are available to the public for research use. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

16 pages, 9793 KiB

Open AccessArticle

Design and Hydrodynamic Experiment Research on Novel Biomimetic Pectoral Fins of a Ray-Inspired Robotic Fish

by Lingkun Chen, Shusheng Bi, Yueri Cai and Hongcheng Qiu

Machines 2022, 10(8), 606; https://doi.org/10.3390/machines10080606 - 25 Jul 2022

Cited by 4 | Viewed by 2239

Abstract

Bionic propulsion has certain advantages over traditional propellers. Much research on pectoral fins as bionic propellers for ray-inspired robots has been made, but rarely did they compare the hydrodynamic performance of different fins on the same platform to find out optimal balance. In this paper, the existing prototypes are categorized into three structure types, and a new bionic pectoral fin module used on a ray-inspired robotic fish was presented, together with a novel 2-DOF spatial parallel mechanism as the bionic propeller. Motion analysis of the mechanism agreed well with the pectoral fin kinematic model, providing a reliable basis to test different types of fins. Design and fabrication of the new bionic fin module as well as two traditional ones are also explained. Hydrodynamic experiment was conducted to study the differences between each fin type under various working conditions. Results indicate that the thrust generated by the fin oscillation is closely related to four parameters (amplitude, frequency, phase difference, and flow velocity), and there are optimal value ranges for better propelling performance when the frequency is around 0.5 Hz and phase difference is near 30°. Thanks to better profile preservation and hydro force interaction, the newly proposed pectoral fins had higher performance than the traditional ones in terms of thrust generation and controllability when the amplitude is higher than 30° and frequency is over 0.3 Hz. An average thrust of 2.98 N was recorded for the new fin module at the max amplitude of 60°, 11.6% and 16.4% higher than the other two comparative test groups, respectively. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

21 pages, 2299 KiB

Open AccessArticle

An Improved Backstepping Controller with an LESO and TDs for Robust Underwater 3D Trajectory Tracking of a Turtle-Inspired Amphibious Spherical Robot

by Xihuan Hou, Zan Li, Shuxiang Guo, Liwei Shi, Huiming Xing and He Yin

Machines 2022, 10(6), 450; https://doi.org/10.3390/machines10060450 - 6 Jun 2022

Cited by 5 | Viewed by 1837

Abstract

In this paper, a double closed-loop backstepping controller is designed for 3D trajectory tracking of a turtle-inspired amphibious spherical robot suffering from problems that include model uncertainties, environmental disturbances, and unmeasured velocity. The proposed controller scheme tackles three primary challenges: the differentiation explosion of the traditional backstepping method, unmeasured velocity, and the consideration of lumped disturbances. Beginning with an outer-loop backstepping controller, a virtual feedback variable is constructed to simplify the design of the backstepping controller. Meanwhile, to avoid the problem of differentiation explosion, tracking differentiators (TDs) are utilized to estimate the differentiation of the desired velocity in an inner-loop backstepping controller. Moreover, there are some uncertainty disturbances in the task of tracking the trajectory of a turtle-inspired amphibious spherical robot (TASR), such as the parameters of the hydrodynamic model and environmental disturbances. A linear extended state observer (LESO) is designed to estimate and compensate for the lumped disturbances. Furthermore, as the velocity states of the TASR are unmeasured, the LESO is also utilized to estimate the velocity states in surge, yaw, and heave degrees. Therefore, the TASR only needs to supply its position and orientation information for the trajectory tracking task. Note that this paper details both the design process of the proposed controller and a rigorous theoretical analysis. In addition, numerical simulations are conducted, and the results demonstrate the feasibility and superiority of the proposed method. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

23 pages, 13602 KiB

Open AccessArticle

An Innovative Pose Control Mechanism for a Small Rudderless Underwater Vehicle

by Min-Fan Ricky Lee and Yen-Chun Chen

Machines 2022, 10(5), 352; https://doi.org/10.3390/machines10050352 - 9 May 2022

Cited by 2 | Viewed by 2844

Abstract

Current and conventional pose (position and orientation) control of a small underwater vehicle is achieved by using rudders (yaw motion control) and elevators (pitch motion control), but these suffer from non-linear, indirect and complex control issues. This paper proposes an innovative pose control mechanism for small underwater vehicles. The mass shifter mechanism is designed and fabricated to control pitch and yaw motion with a single propeller only. The center of mass of the underwater vehicle is altered by moving a pair of counterweights on fixed tracks. The pitch and yaw are achieved by controlling the position of the counterweight pairs. The proposed system is designed, fabricated and tested in a real underwater environment for proof-of-concept. The result shows a simpler, more efficient and more effective pose control mechanism than conventional technology. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

16 pages, 3510 KiB

Open AccessArticle

Experimental Study on Multi-Domain Fault Features of AUV with Weak Thruster Fault

by Dacheng Yu, Chenguang Zhu, Mingjun Zhang and Xing Liu

Machines 2022, 10(4), 236; https://doi.org/10.3390/machines10040236 - 27 Mar 2022

Cited by 10 | Viewed by 1876

Abstract

As the most important device of an Autonomous Underwater Vehicle (AUV), thrusters are one of the main sources of fault. If the thruster fault can be diagnosed in the early stage, it would give more time to guarantee the safety of an AUV. Fault feature extraction is the premise of fault diagnosis. The traditional feature calculation methods extract fault features from one domain. These methods work well in the case of high fault severity, but poorly in the case of weak fault severity. In addition, for weak faults, the fault features extracted by the traditional methods may not meet the monotonic relationship with fault severity and cannot be used in fault severity identification. Aiming at these problems, through experimental data analysis, this paper excludes the features that do not meet the law from the 52 selectable fault features in the time domain, frequency domain and time-frequency domain. Aiming at the problem that there is no useful feature in the frequency domain, a new feature calculation method is proposed, and the order of magnitude of the available feature is given, which provides concise and accurate information for subsequent fault feature fusion and fault severity identification. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

13 pages, 3554 KiB

Open AccessArticle

A Novel Fish-Inspired Robot with a Double-Cam Mechanism

by Zhibin Song, Zhongru Fu, Donato Romano, Paolo Dario and Rongjie Kang

Machines 2022, 10(3), 190; https://doi.org/10.3390/machines10030190 - 6 Mar 2022

Cited by 7 | Viewed by 3463

Abstract

Fishes have evolved different excellent swimming strategies. To study the influence of tail fin swing on the swimming performance of bionic robot fish, with one joint under the same tail swing frequency and amplitude, we designed a novel robot fish, driven by a double-cam mechanism. By designing the profile of the cam in the mechanism, the robot fish can achieve different undulatory motion trajectory of the caudal fin under the same tail swing frequency and amplitude. The mechanism simulated the undulatory motion of crucian carp. We studied the influence of undulatory motion on the swimming speed of robot fish, which was analyzed by dynamic analysis of the undulatory motion and experiments. According to the experimental results, we can find that the swimming speed of the robotic fish is different under various wave motions. When other conditions are the same, the speed that the robot fish can achieve by imitating the swing motion of the real fish is 1.5 times that of the robot fish doing the cycloid motion. The experimental results correspond to the kinetic analysis results. Furthermore, it is proven that the robot fish with a low caudal peduncle stiffness swims faster under a low swinging frequency, and the speed of a robot fish with a high caudal peduncle stiffness is higher under a high tail swinging frequency. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

11 pages, 4157 KiB

Open AccessEditor’s ChoiceArticle

Experimental Research on the Coupling Relationship between Fishtail Stiffness and Undulatory Frequency

by Yuanhao Zhang, Rongjie Kang, Donato Romano, Paolo Dario and Zhibin Song

Machines 2022, 10(3), 182; https://doi.org/10.3390/machines10030182 - 3 Mar 2022

Cited by 5 | Viewed by 2066

Abstract

Fish can swim in a variety of states. For example, they look flexible and perform low-frequency undulatory locomotion when cruising, but they seem very powerful and stiff and perform high-frequency undulatory when hunting. In the process of changing the motion state, the stiffness of the fish body affects the swimming performance of the fish. In this article, we imitated the change of stiffness by superimposing rubber sheets and used experimental methods to test its swimming performance under different swing frequencies. A series of rubber fish tails were made according to the analysis of the swimming movement of real fish, providing different stiffness values and changing the curves of the body. In the prototype experiments, the base of the fish tail was fixed to a platform via a force sensor, which can oscillate at various speeds, so that the fish tail was able to swing and the thrust could be tested at different frequencies. According to the experimental results, we found that with the change of the swing frequency, there were different optimal stiffnesses that could make the thrust reach the maximum value, and with the increase of stiffness, the envelope interval of the swing curve gradually widened, the amplitude increased, and the hysteresis of the tail fin relative to the end decreased. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Figure 1

15 pages, 5722 KiB

Open AccessArticle

Stiffness Modelling and Performance Evaluation of a Soft Cardiac Fixator Flexible Arm with Granular Jamming

by Likun Gao, Yanlin He, Hangwei Zhu, Guangkai Sun and Lianqing Zhu

Machines 2021, 9(12), 303; https://doi.org/10.3390/machines9120303 - 23 Nov 2021

Cited by 5 | Viewed by 1958

Abstract

To meet the practical application requirements of cardiac fixation during off-pump coronary artery bypass surgery, a soft cardiac fixator with a flexible arm was previously designed. To enable the soft cardiac fixator to adapt to uncertain external forces, this study evaluates the variable-stiffness performance of the flexible arm. First, the flexible arm was simplified as a soft silicone manipulator measuring 60 mm × 90 mm × 120 mm, which can actuate, soften, or stiffen independently along the length of the arm by combining granular jamming with input pressure. Then, the soft manipulator was modelled as a cantilever beam to analyse its variable-stiffness performance with granular jamming. Next, based on theoretical analysis and calculations, many experiments were conducted to evaluate the variable-stiffness performance of the soft manipulator. The experimental results demonstrated that the variable-stiffness performance is influenced by the flexible arm length, the size of the granules, and the input pressure. Full article

(This article belongs to the Special Issue Advances in Underwater Robot Technology)

► Show Figures

Journal Menu

Journal Browser

Advances in Underwater Robot Technology

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (10 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI