Basic design concept

The basic design concept of the AUV ISiMI is hinged on the implementation of a small vehicle that can be easily launched, recovered and operated without special handling equipment. This concept of a small AUV is intended to provide researchers with fast experimental feedback on new algorithms and instruments necessary to develop AUV technologies. Several AUVs were reviewed to lead the concept of ISiMI. Sea Squirt AUV, which is 1m long and weighs 35 kg, was built in 1988 under the MIT Sea Grant...

Modeling experiments of pipeline inspection

Investigation of AUV behavior during inspection of pipeline, which is partly filled up with ground, was carried out by means of modeling. The modeling environment includes 3D-model of bottom surface and artificial objects (pipeline in this case) AUV dynamic and kinematics models The model of bottom surface (fig. 9) along with model of artificial objects allows to form any terrain shapes, including concave and ambiguous (Pavin, 2005). The model includes three basic levels of detailed...

Ictiobots architecture

The modular architecture of the prototype is based on the aims and working hypotheses previously described, and it is presented in figure 2, showing the basic modules of any autonomous robot, that is, the mission planner planner, guidance, control, and navigation systems. The DMP system comprises the EN4AUV knowledge based system and an OAS, based on evolutionary robotic paradigm developed for terrestrial applications (Fern ndez Le n, et al. 2004). Both modules, jointly with the guidance and...

Introduction

The research on underwater systems has gained an immense interest during the last decades with applications taken place in many fields such as exploration, investigation, repair, construction, etc. Hereby, control of underwater systems has emerged as a growing field of research. Underwater vehicles, in fact, accounted for 21 of the total number of service robots by the end of 2004, and are the most expensive class of service robots (UNECE IFR, 2005). Typically, underwater vehicles can be...

Navigation

The design of the navigation system of an AUV has to take into account several issues such as desired positioning and attitude accuracy, size, weight, and power consumption of available sensors and systems, and also overall cost. Available technologies include inertial navigation systems, digital compasses, tilt sensors, pressure cells, acoustic positioning systems, and Doppler based velocity meters. The MARES navigation package was selected taking into account the above mentioned issues but...

Reference

YinSheng Zhang, Underwater Archaeology and Its Exploration Technology, Southeast Culture, no. 4, pp. 29-33, 1996.in chinese. XiSheng Feng, From Remotely Operated Vehicles to Autonomous Undersea Vehicles, Engineering Science, vol. 2, no. 12, pp. 29-33, Dec 2000. .in chinese. JunFeng Huang, et al, Remote Operated Vehicle(ROV) Dynamic Positioning Based on USBL(Ultra Short Base Line), Control Engineering of China, vol. 9, no. 6, pp. 75-78, Nov 2002 .in chinese. Fish-like swimming, F. E. Fish and J....

1950 Underwater Vehicle

The problem of power and communication limitation in underwater environment makes it more challenge to increase the degree of autonomy and intelligence for an autonomous underwater vehicle (AUV). An infrastructure of autonomous teleoperation platform for AUV is established and described, which allows control to be shared between the intelligent decision system in AUV system and operators throughout a mission. In the (Paunicka J.L. et al., 2001, Wills L. et al., 2000, and Wills L. et al., 2003),...

Conclusion

In this study, position control of the UUV as the application of a novel optimal control was discussed. The dynamics and control of the 6-DOF UUV are presented and the new optimal control method was introduced. To the best knowledge of the authors, there is no 6-DOF underwater vehicle that can be controlled with one actuator in literature. Based on this control approach, the criteria function determined included a terminal error function. The terminal error function plays an important role in...

Final approach algorithm

It was first suggested by Deltheil et al (2000) that a vision system is suitable for docking because it offers simplicity, stealthiness and robustness. In this chapter, a final approach algorithm based on vision-guidance is suggested. It was supposed that the AUV could be guided to the dock by controlling only yaw and pitch. This final approach algorithm generates reference yaw and reference pitch and makes the AUV track them. The docking stage begins when the AUV arrives within 10-15 m in...

Military vehicles

The military has developed an advanced underwater winged glider based on the air force's Flying Wing design, the Liberdade XRAY (see Figure 11). This vehicle is being developed as a part of the Navy's Persistent Littoral Undersea Surveillance Network (PLUSNet) system of semi-autonomous controlled mobile assets. PLUSNet uses unmanned underwater vehicles (UUVs) and autonomous underwater vehicles (AUVs) to monitor shallow-water environments from fixed positions on the ocean floor or by moving...

Info

Y m u + ur - wq + Xq (pq + r) - yQ (p + r ) + Zq (qr - p) Z m w- uq + up + XQ(pr - q) + yQ(qr + p) - Zq(p2 + q2) K Ixp+(Iz- Iy)qr+Ixy(pr - q) - Iyz (q - r ) - Ixz(pq+r)+m yQ(w - uq+up ) - zQ(u+ur - wp) M Iyq+(Ix- Iz) pr -1 xy (qr+p) -1yz(pq - r) - Ixz(p2 - r 2)+m xq (w - uq+up) - zq (u -ur+wq) n Izr+(Iy - Ix) pq -1 xy(p2 - q2) - Iyz(pr + q)+Ixz (qr - p)+m xq (u+ur - wp) - yQ(u-ur - wq) where, X, Y, and Z are surge, sway, and heave force K, M, and N are roll, pitch, and yaw moment p, q, and r...

Closest Scuba Diving From Chicago

3.3 Collision risk computation system The Collision Risk Computation System uses information from the surrounding environment as well as the obstacle and positioning information to compute the risk of the autonomous underwater vehicle colliding with various obstacles that exist in its environment (Kim, 2001 Hara & Hammer, 1993). The system provides a basis for the decisions it makes so that if the system finds the autonomous underwater vehicle at risk of colliding with an obstacle, it...

Iterative solutions using linear programming

Linear approximations to the thrust allocation problem have been discussed by Webster and Sousa (1999) and Lindfors (1993). In Linfors (1993) the azimuth thrust constraints f V(f cos a )2 + (f sin a )2 < f (1.46) are represented as circles in the (f cos a, ft sin a) -plane. The nonlinear program is transformed to a linear programming (LP) problem by approximating the azimuth thrust constraints by straight lines forming a polygon. If 8 lines are used to approximate the circles (octagons), the...

Ps

Inference rules for degree of collision risk Table 1. Inference rules for degree of collision risk Table 1 is the inference rule table used to compute the collision risk. It was preset based on a navigation expert's knowledge and this can be changed depending on any particular navigator's experience or knowledge. The simulation system is a software that lets users experiment through a computer the autonomous underwater vehicle's overall navigation process as well as the objects that...

Acknowledgement

The first author would like to acknowledge helpful discussion and solid support from the co-authors of the chapter. The European Marie Curie Research Fellowship and the wonderful team in the research project FREESUBNET under grant 036186 give the first author a great support for the finalization of the chapter. This work was also funded in part by the National Natural Science Foundation of China under grant 69585003, and in part by the National 863 Hi-tech Research and Development Program of...

Cd Parv

Where CL is the fin lift coefficient, CD is the fin drag coefficient, AR is the fin planform area, and ve is the effective fin velocity. The values of lift coefficient CL and drag coefficient CD are related with effective fin angle of attack a . We can adopt experiment, theroy computation, or empirical fomular to get CL and CD . Experiment and empirical fomular method will be introduced below. 1. Actual measurement from exprement A series of data of angles of attack a vs. lift coefficient CL...

Scuba Diving Conclusion

Autonomous Underwater Vehicles are only now being marketed as robust commercial vehicles for many industries, and of these vehicles underwater gliders are becoming the new tool for oceanographers. Satellites have provided scientists and marine specialists with measurements of the sea surface such as temperature since the late 1970s, and data via subsurface oceanographic moorings since the 1950's. As stated by David Smeed of the National Oceanography Centre, Southampton, England, that gliders...

Behavior based chemical plume tracing

Fig. 5 displays the behaviors and switching logic used to implement CPT algorithms using BBP. In Fig. 5, S and d are Boolean variables. The symbols S and S indicate that the source location has or has not been declared, respectively. The symbol d indicates that chemical has been detected. The symbol d indicates that the behavior completed without detecting chemical. Prior to source declaration, whenever chemical is detected, the Track-In behavior Fig. 5. Behavior Switching Diagram. The symbol d...

Auv

O AUV +a < VIC> - sign (a < VIC> )-900 '< VIC> p< VIC> . sin(a < VIC> ) y< Vic> p< Vic> . COs(a < V1C> ) Where x ' t< VIC> , y' t< VIC> - object position on the video camera image AxVIC, AyVIC - onboard camera position G( ) - turn-matrix of coordinate system to an angle It is necessary to note that video recognition system does not guarantee reliable results due to noisy objects can be present on images (starfishes, alga, stones, sea garbage and so on) or...

DIS navigation system

A prototype of such acoustic navigation system proposed in this chapter consists of a set of light surface buoys usually more than three of them. The physical characteristics of the buoys with acoustic module(hydrophone), in terms of size, weight and autonomy, will tend to those of a standard sonobuoy, with however the capability of micro-controller, processing of acoustic signals, local data storage, and online transmission by a radio modem. The most peculiar characteristic is a DGPS receiver...

Control

The general dynamic model of an underwater vehicle follows the 6 degrees of freedom template presented in (Fossen, 1994). It is a complete model that takes into account all the forces and moments acting on a submerged body, but for which it is not easy to design adequate controllers. Typically, AUVs evolve according to two dimensional motions, either in the vertical or in the horizontal plane. Therefore, the traditional approach for the control of theses vehicles is based on mode decoupling...

Modern power sources

Power sources are extremely important in underwater vehicle development, in particular for AUVs, UROVs and HROVs. Power source capacity limits the cruising range and mission style of underwater vehicles. Two main evaluation factors for power sources are the specific energy, energy per unit mass Wh kg, and the energy density, energy per unit volume Wh L. In vehicle design, not only the energy of the power source is considered, but also the maximum output power. In this section, modern power...

Schooling for Multiple Underactuated AUVs

Ji-Hong Li, Bong-Huan Jun, Pan-Mook Lee and Yong-Kon Lim Maritime & Ocean Engineering Research Institute, KORDI, In the past few decades, autonomous underwater vehicles (AUVs) have been playing one of most important roles in the applications ranging from scientific research, survey to industry and military operations. Today, there is an apparent trend that more and more underwater tasks are carrying out by cooperative operations of multiple AUVs instead of traditional method of using single...

L

Ypb kL ysb kL yps kL yss kL Since the fin-induced drag is proportional to the square of the angle of attack, a natural objective function to minimize in the control allocation problem is a quadratic function. Depending on the difference in size and hydrodynamic characteristics of the bow and stern hydrofoils, we could perhaps use a different weighting to the two sets of fins. Thus, the fin allocation problem can be formulated as a standard quadratic program mm frWf + sT Qs subject to T f t - s

Mosaicking

Light attenuation and backscatter inhibit the ability of a vision system to capture large area images of the sea floor. Image mosaicking is an attempt to overcome this limitation using a process of aligning short range images of the seabed to create one large composite map. Image mosaicking can be used as an aid to other applications such as navigation, wreckage visualisation, station keeping and also to promote a better understanding of the sea floor in areas such as biology and geology....

Underwater optical imaging

Underwater optical imaging has many interesting and beneficial attributes for underwater vehicle navigation, as well as its ability to open up a wealth of understanding of the underwater world. However, it is not an ideal environment for optical imaging as many of its properties inherently affect the quality of image data. While image quality is a pertinent issue for vision system performance, other difficulties are also encountered such as the lack of distinguishable features found on the...

Computed torque control method

This section presents a nonlinear control method, apparently first proposed in (Paul, 1972) and named the computed torque method in (Markiewicz, 1973) and (Bejczy, 1974). This method is based on using the dynamic model of the system in the control law formulation. Such a control formulation yields a controller that suppresses disturbances and tracks desired trajectories uniformly in all configurations of the system (Craig, 1988). Suppose that the system's dynamics is governed by Eq. (1). The...

Qipi qipi j

+ Z Yvuuhi (uh - un) + YwVhi iVh - Vn) J' (ulv C0SVlv - Xi ) + VVhl (ulv SinVlv - Vi ) (uh cosvh - Xi) + -f -(uh smvh -Vi) qvki qvki (uiv cosVh-xi) TrVip 7(uiv sinVh-y) + Z Yuuivi (uiv - un) + YvVivi (Wh - Vii) i 1 Z a xi (ulv cosVlv - uli cosVli) + A Vi (ulv sin Vlv - uli sin Vli ) + A O + Yuulvi (ulv - uii) + YwVlvi (Wh - Vli) (Axi cosVli +A Vi sinVii )uhi + 2uh I A cosVlv +Vli - Axi ivn V I sin + A o + Yuu lvi(u lv - fui C0SVai - Li sVnVai - bui C0SVai Tui ) + YwVlvi (Vlv at -ari + eri )...

Localization in the OEB

The localization problem is a major challenge in underwater robotics. In the OEB environment, there is a severe constraint to using an acoustic positioning system due to the multi-path of the acoustic signal reflected from the wall and bottom of the OEB and from the free surface. Therefore, the image tracking system on the CPMC in the OEB is used for the non-contract position tracking of ISiMI. The CPMC has a three-degrees-of-freedom moving mechanism that enables ISiMI to follow the x-y...

Acoustic navigation

Acoustic Diver Positioning System

The simple transition from available navigation techniques based on electromagnetic signals for mobile robots or flying robots to underwater vehicles, is not applicable due to the peculiarities and constraints of the underwater environment, as the electromagnetic signals do not penetrate below the sea surface. The good propagation characteristics of sound waves in water makes acoustic positioning and navigation as a feasible candidate, and the related study of the implications of such...

Cooperative navigation architecture for heterogenous AUVs

With the underwater DGPS concept and the underwater acoustic navigation approach, the position of the AUV can be achieved with high precise given a set of range measurement from the AUV to known sonobuoys locations. In the set-up adopted for vehicle positioning the underwater pinger of an AUV carries a high precision clock that is synchronized with those of the sonobuoys (and thus with DGPS) prior to AUVs deployment. The pinger emits an acoustic signal every T seconds, at precisely known...

References

AUV Equipment and Control While Conducting Investigation of Underwater Pipeline (in Russian), Underwater Technologies, Nal, pp. 68-72, Dalnauka, Vladivostok, Russia Asai, T. Kojima, J. Asakawa, K. & Iso, T. (2000). Inspection of submarine cable of over 400 km by AUV, Proceedings of the 2ooo International Symposium on Underwater Technology, UT oo, pp. 133 - 135, May 2000, Tokyo, Japan Baker, J. (1991). Alternative Approaches to Pipeline Survey. Subtech'91, Vol. 27, pp....

S Jacinto outfall

A map of the study area is shown in Fig. 2. The S. Jacinto outfall is located off the Portuguese west coast near the Aveiro estuary. The total length of the outfall, including the diffuser, is 3378 m (the first 3135 m section having a diameter of 1600 mm and the last 243 m section having a diameter of 1200 mm). The diffuser consisting of 72 ports alternating on each side, nominally 0.175 m in diameter, is 332.5 m long. Currently, only the last 20 of the 72 ports are working in a length of 98.2...

Long Baseline LBL positioning

Long baseline (LBL) positioning is a standard in underwater navigation. First used in the 1960's and 1970's (Hunt, Marquet, Moller, Peal, Smith, & Spindel, 1974), the foundational idea of using acoustic transponders moored to the seafloor has been used to fix the position of a wide spectrum underwater assets submersibles, towed instrumentation, ROVs and AUVs. Fig. 4 illustrates the basic LBL method for use with an AUV. For each navigation cycle the vehicle measures the two-way time-of-flight...

Bpsk

Solutions with ROVs, UROVs and HROVs. In recent years, data traffic on networks has drastically increased with the evolution of broadband networks. In order to meet the demand, developers are trying to develop a 40 Gbps optical communication system using a dense wavelength division multiplexing technique for land and submergible cable applications. For wireless remote control and status monitoring of AUVs, an acoustic communication system or an acoustic modem is used. This is also effective for...

Dilution of precision

Dilution of precision metrics are common in GPS applications. The horizontal dilution of precision comes directly from the Cartesian components (x and y) of the position estimate covariance matrix in equation (20). The HDOP metric is normalized by the range uncertainty (ffr)to isolate the sensitivity of the metric to the solutions geometry. Fig. 7 illustrates how this Cartesian interpretation overestimates the uncertainty by describing a rectangular boundary of uncertainty ellipse.

Fast Marching algorithm 341 Pseudocode

The pseudo code of the Fast Marching algorithm is given in table 1. The FM algorithm relies on a partitioning of the C-space in three sets Accepted configurations for which the distance function u has been computed and frozen, Current configurations for which an estimate v of u has been estimated (and not frozen), and the remaining Unvisited configurations for which u is unknown. Start is the set of start configurations Goal is the set of goal configurations Neigh(S) is the set of neighbours of...

Other vehicles

Another vehicle that will soon come to market is Liquid Robotics' entirely new autonomous ocean vehicle WaveGlider that harvests all of its energy from waves and sun. The concept is a shallow water vehicle that uses the ocean waves as its primary energy source to propel it through the water. During the spring and summer of 2008 the WaveGlider underwent extended periods of field testing in the Pacific Ocean. The design consists of a surface float (similar to a surfboard) that is tethered to a...

Station keeping

The ability for submersible vehicles to accurately maintain position and orientation is a necessity. The process of maintaining a vehicle's predefined pose in the presence of disturbances (undersea currents and reaction forces from manipulators attached to vehicle) is known as station keeping. Station keeping can be used for many different underwater applications such as repair of underwater structures and near seabed data collection. Station keeping using a vision system has the advantage of...

Waypoint tracking

ISiMI was guided to track a figure-eight trajectory to test the LOS algorithm described in Section 4.2. The position of ISiMI was measured using the image tracking system in CPMC, and transmitted to ISiMI via the R F link. The position of the waypoints was pre-recorded in ISiMI's memory. The threshold level po in (11) was 1 meter. The results are plotted in Fig. 15. The yaw angle in Fig. 15 was controlled by the PD controller to follow the yaw reference generated by the LOS. It was verified...

Positioning localisation

The possibilities of using vision systems for navigation have already been discussed in the case of mosaicking, station keeping and cable tracking. For the purposes of this review vision based navigation will be discussed in relation to mosaic based localisation, Simultaneous Localisation and Mapping (SLAM) and motion estimation. Image mosaics are a large area composite view of the seafloor. This composite view is effectively a map of the area over which the vehicle has passed during the...

Underwater archaeology experiment

At present, SPC-II can elementarily fulfill the need of underwater archaeology and it also has some advantages in environment disturbance and horizontal maneuverability. But the ascending and submergence of SPC-II are implemented by changing the pectoral fin's incidence angle, so it can dive only in the process of swimming (submergence velocity is the minimum straightforward velocity of submergence). In addition, it can not swim back off and hasn't the underwater position system. All of which...

AUV movement control during pipeline or cable tracking

AUV motion during the pipeline inspection has the features connected with freespan investigation. In the literature the task of main stage is not formalized and usually reduced to the list of the AUV desirable actions. In the paper the following sequence of actions is offered for the implementation of main stage (fig. 8) 1. AUV moves directly above the pipeline, thus leakage detection is fulfilled (the methane sensor is used usually for these purposes) the video filming of the pipe surface is...

R

Parameter settings for CPT strategy for the April 2003 SCI and June 2003 Duck experiments. Table 4. Parameter settings for CPT strategy for the April 2003 SCI and June 2003 Duck experiments. Two types of missions were of interest during this set of experiments. The first mission type, labeled ST, contained a single chemical source in the OpArea. The ST mission was intended to find the plume, to trace a plume over a long distance, and to declare the source location. This mission...

Path planning

Regardless of the control architecture chosen, some sort of planning is typically necessary to maintain safety and efficiency of the system. Planning can be done both before and during the mission (replanning). By replanning the path, the vehicle is able to account for changes in its internal status and in the environment. The plan typically constitutes an explicit path to follow, but can alternatively be in the form of an artificial potential field used by the vehicle to guide it (Tan et al.,...

Requirement of underwater archaeology to UUV

Because of the particularity of the environment and objects of underwater archaeology, there are some special demands for the robot and the equipment, which are described as follows The disturbance and destruction to the environment should be as little as possible. It is hard to avoid shuttling in the site back and forth when the underwater robot is working and the result would be serious if the cultural relic was shattered. The silt aroused by disturbance can also affect the collecting of...

Micro deltaposition aiding

Some of the sensors carried by an AUV can observe the same part of the seafloor in consecutive sensor measurements, such as a Synthetic Aperture Sonar SAS , a 3D sonar, or a camera. By correlating these consecutive measurements of the same seafloor patch over a small time interval, a measurement of the change of the AUVs position between these measurement times may be derived. A Correlation Velocity Log CVL is another sensor that provides a similar measurement, although using a different...

Scientific sensors

An autonomous oceanographic data acquisition vehicle glider that is usable by a wide range of scientists must be able to accommodate many different scientific instrumentation configurations, be capable of collecting specimens and be able to perform the missions as specified. Sensor packages are instrumental to a vehicle. Slocum, Spray, Seaglider and WaveGlider are too small for use with many types of instruments. Additionally, the sawtooth glide pattern is not optimal for certain types of data...

Vehicles

Looking at the current situation in AUV technology see Figure 1 , there are currently over 50 different types of AUVs in research and commercial operation, just a few of these systems are Hydroid's REMUS USA , Bluefin Robotics Corporation's Odyssey USA , Woods Hole's ABE USA , FAU's USA , Boeing's, Oceaneering's and Fugro's Echo Ranger USA , Kongsberg Simrad's Hugin 3000 Norway , Sias-Patterson's Fetch USA , University of Southampton's AUTOSUB England , Alive and Swimmer France , and Hafmynd's...

Overview of ISiMI

In the consideration of the design concept, a first version of ISiMI was manufactured with fundamental sensors that were required to enable it to cruise in the OEB. The appearance of ISiMI is shown in Fig. 1. Adopting the modular design concept, we can insert additional mission sensors by extending the length of the AUV's mid-section hull. Fig. 2 shows the ISiMI hull that was extended by inserting an acoustic telemetry module, and Table 1 shows a comparison of the principal dimensions of ISiMI...

Cooperative navigation algorithm

Problem statement Given the simultaneous information of sonobuoys positions and the TOAs at different sonobuoys, and assuming the measurement performed each time affected by a bounded error accounting for all the uncertainties, then the simultaneous Least Squared LS navigation algorithm could be proposed for cooperative navigation for heterogenous AUVs, and the observation equations could be made. The Taylor-series will give a Least Squared error solution to a set of simultaneous nonlinear...

Underwater docking experiments

The goal of the experiments was to verify the final approach algorithm and system validity. Figure 23 describes the initial start point for the final docking approach. It shows a top view left and a side view right of the initial start conditions. The dock was placed within viewing range of the camera. The center of the dock was placed at a depth of 1.5m. The dock was introduced by Lee et al, 2003 , Park et al, 2007 . The dock was funnel-shaped. This shape makes it possible for the AUV to dock...

Mission transects

Within the near field, plumes are energetically turbulent with wide variations in instantaneous measurements Roberts, 1996 . Sampling within this area is therefore problematic as results may fluctuate widely and be difficult to interpret. One of the main goals of this work was to develop a reliable in situ method to monitor pollutants discharged in the environment with increased temporal and spatial resolution, making use of an AUV. In order to reduce the uncertainty about plume location and...

Image processing

In this chpater, image processing means detecting and discriminating the location of the lights on the dock and estimating relative position and distance between the AUV and the dock. Figure. 16 shows a developed dock and the arrangement of the lights in the entrance of the dock. The diameter of the rim was 1m. Five lights were installed in the circular rim. The locations and brightness of the lights were adjustable. Before the image processing, it was necessary to adjust the intensity of the...

Description of the system

To obtain the mathematical model, the specifications and the assumptions which enable the formulation of kinematic and dynamic equations are needed. The simple model of the UUV holds the essential dynamical properties. A hull having a scalene ellipsoidal shape is shown in Fig.1. As illustrated in Fig.1, the UUV has a flat type of hull. For simulations, the UUV is assumed as neutrally buoyant and completely rigid. The fluid, which the vehicle interacts with, is considered as an ideal fluid...

Isurus AUV

Isurus is a REMUS class AUV, acquired to the Woods Hole Oceanographic Institution, MA, USA, in 1997 Fig. 1 . These vehicles are low cost, lightweight AUVs specially designed for coastal waters monitoring Alt et al., 1994 . The reduced weight and dimensions make them extremely easy to handle, requiring no special equipment for launching and recovery. Isurus has a diameter of 20 cm and is about 1.5 m long, weighting about 35 kg in air. The maximum forward speed of the vehicle is 2 m s, however...

Resolved Acceleration Control for Underwater Vehicle Manipulator Systems Continuous and Discrete Time Approach

Auv Propeller Spec

Kyushu Institute of Technology Japan Underwater robots, especially Underwater Vehicle-Manipulator Systems UVMS , are expected to have important roles in ocean exploration Yuh, 1995 . Many studies about dynamics and control of UVMS have been reported Maheshi et al., 1991 McMillan et al., 1995 McLain et al., 1996 Tarn et al., 1996 Antonelli amp Chiaverini, 1998 McLain et al., 1998 Antonelli et al., 2000 Sarkar amp Podder, 2001 . However, there are only a few experimental studies. Most of the...

An Autonomous Navigation System for Unmanned Underwater Vehicle

Vehicle Autonomous System Architecture

Seong-Gon Kim1 and Yong-Gi Kim2 University of Florida 2Gyeongsang National University Autonomous underwater vehicles should possess intelligent control software that performs intellectual functions such as cognition, decision and action, which originally belong to the ability of domain expert, since the unmanned underwater robot is required to navigate in hazardous environments where humans do not have direct access to. In this paper, we suggest an intelligent system architecture called the RVC...

Mares

MARES, or Modular Autonomous Robot for Environment Sampling Fig. 1 , is a 1.5m long AUV, designed and built by the Ocean Systems Group. The vehicle can be programmed to follow predefined trajectories, while collecting relevant data with the onboard sensors. MARES can dive up to 100m deep, and unlike similar-sized systems, has vertical thrusters to allow for purely vertical motion in the water column. Forward velocity can be independently defined, from 0 to 2 m s. Major application areas include...

Case study allocation problem formulation for an AUV with control surfaces

Drag Coefficient Auv

Some underwater vehicles perform all their missions at forward speed. In these applications, the vehicle hull design is streamlined so as to reduce hull drag, and the preferred type of control surface is the hydrofoil or fin. Hydrofoils produce lift, which is the useful force for controlling the motion of the vehicle. The side effect of lift generation, however, is drag in other words, drag is the price we pay to obtain lift. Hence, for vehicles with several mounted control surfaces, the...

Of a Biomimetic Tuna

Biomimetic Tuna

Current unmanned undersea vehicles UUVs are almost exclusively propeller driven designs, which must inherently be optimized for a particular speed, sacrificing low speed manoeuvrability for cruising efficiency. Recently, biomimetic approaches to underwater vehicle propulsion have illuminated the exciting possibilities for performance improvements made possible by emulating fish motion. In particular, a number of test vehicles indicate that the carangiform swimming mode employed by highly...

University of Delaware USA

Swimmingstyles

In order to improve the performance of AUVs in terms of efficiency and maneuverability, researchers have proposed biomimetic propulsion systems that swim using flapping fins rather than rotary propellers. This calls for the exploration of unique locomotion characteristics found in a variety of fish for use in underwater robots. Sfakiotakis et. al., 1999 present a good review of fish swimming modes targeted at roboticists interested in aquatic locomotion. A classification scheme of fish...

Cable tracking

Rov Magnetometer Cable

The necessity for frequent underwater cable pipe inspection is becoming more apparent with increased construction of subsea piping networks for the oil and gas industry and heavy international telecommunication traffic. Current methods for the surveillance, inspection and repair of undersea cables pipes utilize remotely operated vehicles ROV controlled from the surface. This work can prove to be very tedious and time consuming while also being prone to human error due to loss of concentration...

Adaptive computed torque control method

In this section, we introduce the adaptive computed torque control method, and derive an adaptation law to estimate the unknown parameters. The control of nonlinear systems with unknown parameters is traditionally approached as an adaptive control problem. Adaptive control is one of the ideas conceived in the 1950's which has firmly remained in the mainstream of research activity with hundreds of papers and several books published every year. One reason for the rapid growth and continuing...

Underwater Glider Control

Underwater Vehicle Thermal Power

Spray's method of travel Spray, 2008b The glide control in Spray is achieved exclusively by axial translation and rotation of internal battery packs. Pitch is controlled simply by moving the center of gravity in the manner of a hang glider. Turning is initiated by rolling. This gives the lift vector a horizontal component and induces vehicle sideslip in the plane of the wing in the direction of the buoyant force. The horizontal component of lift provides the centripetal force for...

Experiment on propulsion and maneuverability

The test system of the complete SPC-III is shown in Figure 4. IFLY40 Autopilot provides it with perfect telemetry function. This paper is focused on power of the propeller, as well as speed, maneuverability of the vehicle. All collected data are added into the protocol through Autopilot before they are sent to the ground station software. The transmission speed is adjustable within the range of 1 10 frames. Fig. 11. SPC-III AUV electrical system Fig. 11. SPC-III AUV electrical system Vehicle...

AUV general architecture for target tracking

Architecture Hardware Auv

The necessary building blocks for an AUV devoted to pipeline and cable tracking are depicted in figure 1, and explained in the following paragraphs. Fig. 1. Building blocks for an AUV software hardware architecture Fig. 1. Building blocks for an AUV software hardware architecture The navigation module is usually referred to the on board sensory systems. It comprises the data fusion necessary to locate precisely in 3D the AUV rigid body and the target position. The usual components within the...

Expert system based dynamic planner

During an inspection, several unforeseen situations might appear like the detection by the FLS of a fishing net, or a complex pattern shape of more than one pipeline over the seabed recognized by the MBE, or simply a detour due to obstacle detection. In these cases, it is hoped that the DMP module exhibits an intelligent behavior. To cope with these real situations in the marine world, it was resorted to the experience and skills of ROV operators. A little part of their knowledge was elicited...

AUV guidance system

A typical AUV chemical plume tracing system includes an adaptive mission planner AMP that rapidly responds to the sensor inputs to generate a trajectory for the AUV to trace the plume. Because the AUV has velocity lt 2 m sec and heading rate lt 10 degree sec constraints and the vehicle navigation system has navigation fixes The vehicle is performing dead-reckoning based on acoustic Doppler data with periodic navigation updates based on data from a long baseline acoustic buoy transponder system....

Prototype Under Water Vehicle

Auv Schematic

ALBAC Glider Schematics Kawaguchi et al., 1993 Hybrid AUV-Powered Gliders AUV-Powered-Glider Another glider under development is a hybrid, which is designed to travel under power, glide mode or both. This vehicle, under development at Florida Institute of Technology, Melbourne Florida, is being designed to obtain water samples, make photographic video images of specimens in the water column and specify the environmental characteristics of the data field. Furthermore, it is expected to...

Et rc pt pj

Note that the lookahead distance A is no longer defined along the path, but in general along the x-axis of the path-fixed frame i.e., along the path tangential associated with the origin of the path-fixed frame . An along-track distance s t can also be computed relative to some fixed point on the circle perimeter if required. 4.4 Steering for regularly parameterized paths Consider a planar path continuously parameterized by a scalar variable me R, such that the position of a...

Underwater GPS navigation

As mentioned above, traditional acoustic solutions for AUV navigation present some installation, calibration constraints and operational limitations. Their performances may be over estimated and in some cases not fully satisfying, and then non-acoustic solutions will be considered here. The traditional non-acoustic approach, is a set of INS on board combining with a GPS receiver, which is also a dominant approach for AUVs. Due to the accumulated error from INS, the AUV must periodically come to...

Control System

Auv Magnetometer General Arrangement

The standard sensors of ISiMI include an AHRS attitude heading reference system , a pressure sensor, a CCD camera, and a voltage sensor to check the battery voltage. The AHRS supplies information on the 3-axis angular velocities, 3-axis accelerations, 2-axis inclinations, and heading to the control system. The depth information is gathered from the pressure sensor. A CCD camera mounted on the nose is used to detect the underwater dock at the final stage of the underwater docking for the...

Automatic sediment sampling ROV at full ocean depth

Sampling Rov

The ABISMO system and its 11,000m-cable store winch are mounted on the dedicated ship Kairei. The ABISMO system consists of an on-board control module which is installed in the ship, a sampling station, a sediment probe, and two samplers. Fig. 16 shows a recovery scene of the station housing the probe. The on-board control module is connected with the station via the primary cable. The secondary cable, which has been newly developed, connects the station and the probe. The sampling station...

Navigation using sensor fusion

Sensor fusion, also known as multi-sensor data fusion MSDF , is the combination of sensory data or data derived from sensory data from different sources in order to achieve better information than would be possible when these sources are used individually. The term better in this case refers to the data and can mean more accurate, noise tolerant, more complete, sensor failure tolerant or data with reduced uncertainty. There are many different issues that require consideration when performing...

Control architectures

A control architecture is a software framework that manages both sensor and actuator systems, thus enabling the AUV to perform a user-specified mission. There are basically three different approaches to control architectures deliberate, reactive and hybrid systems Arkin, 1998 Valavanis et al, 1998 Ridao et al., 2000 Russell amp Norvig, 2003 . Deliberate hierarchical architectures are based on planning using a world model. They allow reasoning and making predictions about the environment. Data...

Terrain navigation

Some of the typical sensors carried by an AUV provide bathymetric measurements either as a main product or by-product. Among these sensors are DVLs, multi beam echosounders, altimeters, and interferometric side scan sonars. The bathymetric measurements from these sensors can be correlated with a pre-obtained digital terrain model DTM of the seafloor, and as a result the AUV position within this DTM may be estimated. This technique is called terrain navigation. The algorithms performing the...

Y Z

Environment information class The 3D Viewer is the component that displays the simulation process in 3D as seen in Fig. 16. The 3D viewer receives information from the environment manager as input and uses OpenGL to render the simulation process in 3D. OpenGL is the software interface to the graphical hardware allows the generation of objects or computations necessary in producing 3D applications. It can run on various hardware platforms but does not support commands with the ability...

GPS surface fix

As seen in Fig. 1, several alternatives may be included for providing the integrated inertial navigation systems with position updates. Obtaining GPS surface fixes is the most intuitive method and should be used whenever practical. The time between surfacing depends on the required navigation accuracy and additional aiding sensors. The following GPS positioning services can be used GPS Standard Positioning Service SPS GPS Precise Positioning Service PPS Real-Time Kinematic GPS RTKGPS GPS SPS is...

Integrated inertial navigation system structure

Underwater Scuba Diving Vechicles

An INS calculates position, velocity and attitude using high frequency data from an Inertial Measurement Unit IMU . An IMU consists of three accelerometers measuring specific force and three gyros measuring angular rate. If left unaided the INS will, after a short period of time, have unacceptable position errors. The position error growth is determined by the class of the IMU, see Table 1. Currently the best available IMU with a feasible size for an AUV gives a position error growth in the...

Doppler Velocity Log DVL deadreckoning

Dvl Doppler Velocity Log

A Doppler velocity log DVL , integrated with a precise heading reference, is another standard instrument for underwater robotics. As a standalone solution, DVL navigation provides a dead-reckoning estimate of position based on discrete measurements of velocity over the seafloor. To produce this dead-reckoning estimate in local coordinates sequential DVL measurements are related to a common coordinate system. Because the raw measurements are made relative to the sensor, the attitude heading,...