Autonomous underwater vehicles (AUVs) are playing an ever-growing role in modern subocean operations, generating a demand for faster, more manoeuvrable designs capable of deployments of increasingly longer durations. In order to meet these demands, vehicle developers have been looking to biological aquatic animals for inspiration. After evolving for millions of years, fish and cetaceans have developed fast efficient locomotion techniques, with levels of manoeuvrability that far outperform conventional engineered marine locomotion systems. This paper aims to give a brief introduction into some of the biologically inspired propulsion mechanisms that have been developed, to explain their strengths, their weaknesses, and the motivation behind them, and then finally to predict future trends in biomimetic AUV propulsion design.

A review of developments towards biologically inspired propulsion systems for autonomous underwater vehicles

Research on biomimetic robotic fish has been undertaken for more than a decade. Various robotic fish prototypes have been developed around the world. Although considerable research efforts have been devoted to understanding the underlying mechanism of fish swimming and construction of fish-like swimming machines, robotic fish have largely remained laboratory curiosities. This paper presents a robotic fish that is designed for application in real-world scenarios. The robotic fish adopts a rigid torpedo-shaped body for the housing of power, electronics, and payload. A compact parallel four-bar mechanism is designed for propulsion and maneuvering. Based on the kinematic analysis of the tail mechanism, the motion control algorithm of joints is presented. The swimming performance of the robotic fish is investigated experimentally. The swimming speed of the robotic fish can reach 1.36 m/s. The turning radius is 1.75 m. Powered by the onboard battery, the robotic fish can operate for up to 20 h. Moreover, the advantages of the biomimetic propulsion approach are shown by comparing the power efficiency and turning performance of the robotic fish with that of a screw-propelled underwater vehicle. The application of the robotic fish in a real-world probe experiment is also presented. © 2010 Wiley Periodicals, Inc. © 2011 Wiley Periodicals, Inc.

Development of a two-joint robotic fish for real-world exploration

A prototype of a biomimetic mantle jet propeller inspired by cuttlefish actuated by SMA wires and a theoretical model for its jet thrust

In recent years that has been a worldwide increase in the utilisation of Autonomous Underwater Vehicles (AUVs) for many diverse subsea applications This has given rise to an increase in the research and development of these vehicles, with a particular focus on extending operational capability and longevity Consequently, this activity has resulted in the design of many different types of AUVs that employ a variety of different propulsion and manoeuvring mechanisms One particular area that has yielded promising results involves the vehicles designs that are biologically inspired or biomimetic This class of AUV replicates the anatomical features of aquatic species in order to exploit some of the benefits associated with this type of swimming eg higher efficiency at low speeds, improved manoeuvrability The study presented in this thesis considers the design and performance analysis of a unique biomimetic AUV design based on the physiology of an adult Atlantic salmon This vehicle, called RoboSalmon, is equipped with a multiple jointed, fully actuated tail that is used to replicate the undulatory swimming gait of a real fish The initial stage of this design process involves the development of a mathematical model to describe the fusion of the dynamics and electro-mechanics of this vehicle This model provides the design specifications for a prototype vehicle, which has been used in water tank trials to collect data Forward swimming and manoeuvring experiments, eg cruise in turning and turning circle swimming patterns, have been conducted for performance analysis and validation purposes This part of the study has illustrated the relationship between the vehicle surge velocity, tail amplitude and tail beat frequency It was found that the maximum surge velocity has been measured at 0143 ms-1 Also, the vehicle has been shown to accomplish turning circle manoeuvres with turning radius just over the half of its body length The final stage of this study involved the design of a heading control system, which changes the course of the vehicle by altering the tail centreline This study allowed the course changing performance of the vehicle to be analysed Furthermore, a line of sight guidance system has been used to navigate the vehicle through a multiple waypoint course in order to show autonomous operation within a simulated environment Moreover, the vehicle has demonstrated satisfactory performance in course changing and tracking operations It is concluded that the RoboSalmon biomimetic AUV exhibits higher propulsive efficiency and manoeuvrability than propeller based underwater vehicles at low speeds Thus the results of this study show that mimicking biology can improve the propulsive and manoeuvring efficiencies of AUVs

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A fully actuated tail propulsion system for a biomimetic autonomous underwater vehicle

This paper presents a robot fish with a wire-driven caudal fin and a pair of pectoral fins. First, the design of the robot fish is presented. The caudal fin is driven through wire-driven mechanism....

Robot fish with two-DOF pectoral fins and a wire-driven caudal fin

Bionic propulsive mechanism is a hot research topic in robotics field. Robofish, as an ultimate carrier of the research results, should exhibit its advantages in practice. First, the requirements of underwater archaeology to underwater vehicles are briefly analyzed. Then the feasibility of SPC-II robofish to perform underwater task is explained in velocity, maneuverability, comparison with UUV (unmanned underwater vehicle), etc. A scheme for underwater archaeology assisted by SPC-II based on hovering dive is presented. Experiments validate this scheme that makes up to SPC-II for lack of dynamic positioning and supplies reference to future research

Dan Zou

Papers

Experiment of robofish aided underwater archaeology