Biomimetic Autonomous Underwater Vehicle Research Articles

Sound Silencing Problem of Underwater Vehicles

This paper describes some common problems associated with negative influence of UUV self noise on detection aspect in water environment. Some tasks of military applications require silent behavior of UUVs: Intelligence, Surveillance, and Reconnaissance (ISR), Rapid Environmental Assessment (REA), Mine Countermeasure (MCM) etc. Moreover, this paper review methods of underwater sound measurement and on the end as a summary presents results of an experiment from the water tank trials where were investigated three UUVs: one ROV and two biomimetic autonomous underwater vehicle.

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

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.

Maneuvering and control of a biomimetic autonomous underwater vehicle

This work presents an approach for maneuvering and controlling a biomimetic autonomous underwater vehicle (BAUV). The BAUV swims forward by oscillating its body and caudal fin. It turns by bending its body and caudal fin toward the intended direction of motion. A body-spline function is specified by a set of parameters. Genetic algorithms are then used to find the values of the parameter by evaluating a fitness function over several swimming trials in a water tank. The fitness function is defined as the ratio of the kinetic energy of the forward motion to the required driving power of the joint motors. A control law that uses the oscillating frequency to control the forward speed, and applies a body-spline offset parameter to control the yawing rate is proposed. Moving averages of swimming speeds and heading angles are utilized as feedback signals to control the forward speed and heading angle of the BAUV. The effectiveness of the control algorithm is experimentally confirmed.

Mooring cable tracking using active vision for a biomimetic autonomous underwater vehicle

This study presents a localization system using visual information for guidance and navigation of a biomimetic autonomous underwater vehicle (BAUV). The BAUV tracks a mooring cable using two cameras and sonar. Sonar has good accuracy in detecting longitudinal distances but is poor in detecting lateral distances. Since a stereo image has quantization errors, for the cameras, measurement errors in lateral directions are less than those in the optic-axis direction. An extended Kalman filter was employed to combine observational information derived from the cameras and sonar of the mooring cable position with the navigation data of the BAUV. This work demonstrates, using water tank experiments, the effectiveness of the proposed tracking technique in decreasing uncertainty in position estimations of the BAUV and mooring cable.

Optimal measurement strategies for target tracking by a biomimetic underwater vehicle

This study presents a novel navigation and control system allowing a biomimetic-autonomous underwater vehicle (BAUV) to track a target. A Bayesian approach using an extended Kalman filter and combined localization and environmental mapping by a BAUV are implemented. This strategy selects the best sensor measurement by choosing one of several forward-looking directions. The body of the BAUV moves in a cyclical pattern; thus, an inexpensive echo sounder can be installed on the BAUV head to detect environmental features without the need for expensive scanning devices. The localization and environmental mapping problem is then transformed into a non-linear two-point boundary value problem. Optimal policies are to maintain the accuracy of predicted states and to approach minimal observation cost by solving the control problem. A line-of-sight guidance law is utilized that drives the BAUV to the target. An approach that controls the motion of the body/caudal fin and pectoral fins of the BAUV is utilized for target tracking. Estimation, measurement, and control processes are integrated to form a working system. Experiments using a test bed BAUV confirm the effectiveness of the proposed approach.

POWER REDUCTION BY CONTROLLING JOINT COMPLIANCE FOR THE PROPULSION OF A BIOMIMETIC UNDERWATER VEHICLE

The work describes a compliance control scheme for the caudal joint motion of a biomimetic autonomous underwater vehicle (BAUV). The purpose of the control method is to use the motor power more effectively for propulsion. A symmetric foil executing large-amplitude sway and yaw motions in a flow imitates a flapping tail fin which is used as the propulsive device of BAUV. Motions of the oscillating foil are then actuated by motors through springs. A control method was derived for the determination of the spring compliance for better use of the motors’ driving power. It is verified that the compliance control method can reduce the amount of energy for the foil propulsion and is beneficial for the energy saving design for future BAUVs.

A waypoint-tracking controller for a biomimetic autonomous underwater vehicle

This work develops a control system for the waypoint-tracking of a biomimetic autonomous underwater vehicle (BAUV). The BAUV swims forward by oscillating its body and caudal fin. It turns by bending its body and caudal fin toward the turning direction. The control algorithm uses the oscillating frequency to control the forward velocity, and applies a body-spline offset parameter to control the heading velocity. The motion of the BAUV is undulatory, so moving averages of swimming velocity and heading errors are used as feedback signals. The stability of the control system is discussed using a Lyapunov function. Finally, the effectiveness of the control algorithm is experimentally confirmed.

DOCKING CONTROL FOR A BIOMIMETIC AUTONOMOUS UNDERWATER VEHICLE USING ACTIVE VISION

–A localization system using visual information for the guidance and navigation of a biomimetic-autonomous underwater vehicle (BAUV) is proposed. The BAUV is commanded to track a buoy line of a docking station from a distance. The purpose of the visual sensor is to assist the position estimation for the vehicle. An extended Kalman filter that combines observational information with navigational data is shown to be effective in reducing positional uncertainty of the BAUV and environmental features. Experimental results in a water tank show the validity of the proposed method.

Guidance and control of a biomimetic autonomous underwater vehicle using body-fin propulsion

Autonomous underwater vehicles (AUVs) with rigid hulls and powered by rotary propellers have problems such as inefficient propulsion, difficulties associated with positioning, limited turning agility and imprecise hovering. Recently, research and development into biomimetic AUVs (BAUVs) have accelerated in order to solve the problems of the propulsion of AUVs by propellers. A testbed BAUV is being developed. A local control law that coordinates body angles by periodically alternating the position of the centre-of-mass in local coordinates is developed. Three parameters are found to suffice to coordinate joint angles in carangiform swimming. A global control law is then developed for solving the waypoint tracking problem. The effectiveness of this method is evaluated using computer simulation. The control performance of the BAUV system with model uncertainties for waypoint tracking under the influence of disturbances is also discussed.