Site: Institute of Marine Technology Problems
5a Sukhanov Street
Vladivostok, 690600, Russia
Phone: (4232) 228350
Fax: (4232) 226451

Dates Visited: October 24, 1995; October 25, 1995; October 27, 1995

WTEC Attendees:

R. Blidberg (report author), H. B. Ali, S. Chechin, M. J. DeHaemer, L. Gentry, J. Moniz, J.B. Mooney, D. Walsh

Hosts:

Mikhail D. Ageev

Professor, Director of the Institute.
Email: ageev@eastnet.su

Dr. Vladimir V. Nikiforov

Scientific Secretary

Dr. Solotarov

Acoustic design/systems

Shcherbatjuk

Navigation

Alexander V. Inzartsev

Control System

Boris Kasatkin

Hydroacoustic systems for tracking and navigation

BACKGROUND

The Institute of Marine Technology Problems was founded in 1988. It is directed by Mikhail D. Ageev, a full member of the Russian Academy of Sciences, and fellow of the Marine Technology Society. The scientific staff of the institute numbers about 90; one of them is an academician of the RAS; another is a correspondent member of the RAS; three are academicians of the Academy of Engineering Sciences; and nineteen are professors and doctors of science.

Facilities include about 2000 square meters of laboratory room, CAD engineering, experimental production workshops, a high-pressure chamber for deep water equipment tests, and a small research vessel. Scientific investigations and technical developments are carried out in four fields: underwater robotics, hydrophysics, renewable energy resources, and marine ecological systems monitoring.

The primary focus of the institute is the development of new methods and principles to utilize autonomous undersea systems for research and exploitation of the ocean. Scientists and engineers in the underwater robotics department develop principles of autonomous underwater vehicle movement control, develop algorithms that allow these systems to interact with their surroundings, and continually improve the on-board systems. Experimental prototypes of autonomous underwater vehicles (AUVs), tethered and towed vehicles (ROVs), and navigation and positioning systems are designed at the institute. Experimental operations of modular AUV systems such as the MT-88 series (Fig. 1.6) have proven the utility of these vehicles in carrying out scientific research, area search, and geological surveys, especially in deep water. The institute takes part in international projects in this field and has close scientific and technical contacts with universities, institutes and companies in China, France, South Korea, and the United States.

A second focus of the institute is carried out by the Department of Hydrophysics headed by Victor A. Akulichev, the correspondent member of the RAS, professor, fellow of the Acoustical Society of America, and member of editorial board of such journals as Ultrasonics and Russian Physical Acoustics. This department investigates large-scale inhomogeneities of the water medium (frontal zones, synoptic eddies, currents, etc.) and small-scale inhomogeneities of the water medium (suspensions, gas bubbles, sound scattering layers, turbulence, plankton, etc.) using acoustic methods. Acoustic sources with frequencies of 100 to 1000 Hz are towed at depths of up to 100 m. In addition, deep water sound sources operating up to 1000-1500 m can be used. Drifting, vertical receiving systems with hydrophones at any depth from 0 to 1000 m are used as the receiving array. Using these highly directional parametric acoustic sources and special processing methods, researchers in the department investigate remote acoustic spectroscopy. The experiments have shown the possibility of recording the spatial variability of plankton and suspensions in the upper ocean layer in vertical and horizontal directions. Other results show the possibility of measuring gas bubble concentrations, and the spectral composition and variability of collapsing surface waves or other similar disturbances.

The Laboratory of Renewable Energy Resources and Non-traditional Energetics is headed by A. K. Ilyin, professor, member of International Academy of Sciences, and member of Engineering Sciences Academy and Transport Academy of Russia. This laboratory conducts resource estimation of renewable power sources as well as investigates new technologies to take advantage of alternative energy systems. New concepts have been developed and experiments performed to investigate the use of the thermal energy of the ocean, solar energy, energy of ocean tides, sea waves, wind, and biomass. Some industrial solar water heater units were constructed using laboratory designs.

The Division of Ecologic Systems Monitoring develops automated systems for ecological research, for monitoring the water medium and aquaculture using AUVs designed at the institute. The problems of automating industrial wastewater hydrochemical analysis are defined. The laboratory participates in developing automated systems for ecological monitoring of the Russian Far East. The division is headed by V. I. Dulepov, professor, full member of the Academy of Engineering Sciences and of the International Academy of Sciences of Ecology.

The institute takes part in international projects in the field of ocean science and carries out expeditions on the scientific vessels of FEB RAS.

The WTEC panel toured both the institute located in the center of Vladivostok and a test facility located some distance from the institute. While at the institute, we were shown various hardware and listened to a number of presentations focused on various aspects of AUV system and subsystem technology. The following two summaries detail the information we received; the first focuses on AUV systems and technology whereas the second describes the test facility we visited. It must be stated that the panel was very pleased with efforts of the staff of the institute to provide us with information and to create an environment that encouraged sharing information.

IMTP AUV DESIGN AND EXPERIENCE

The staff of the Institute of Marine Technology Problems has been developing AUV technology since 1972. Several AUVs have been designed, developed, and tested during sea operations.

SKAT Vehicles

SKAT (Fig. 1.5) and SKAT-GEO were designed and built in 1973-76 for operations on the shelf. The original SKAT comprised two large hulls, forming a catamaran-like configuration. Gradually other devices were added. These devices were packaged in small containers and added to the original configuration. Operational experience with the SKAT-GEO showed that it was necessary to have a rather large number of these containers. This led to the idea of modular construction. The propulsion system containing four stern propulsors was another success of these early development efforts. SKAT-GEO was designed for 300 m depth, is 2.3 m in length, and has a mass of 450 kg. The vehicle was equipped with photo and TV cameras with a video recorder and CTD sensors.

Use of the SKAT-GEO in 1974 in Lake Baikal was the institute team's first experience using AUVs to undertake practical tasks focused on solving environmental conditions. The expedition was organized to check the lake pollution by industrial waste waters of the Baikal cellulose-paper plant. The AUV was equipped with hydrochemical sensors and a multichannel data storage system. The AUV made a number of transits at various depths in the area adjoining the plant's waste waters discharge. The measurements allowed a map to be made describing the spatial variability of the impurities polluting the water.

A route survey using video sensors was undertaken in the White Sea. The goal was to identify objects that had been detected with the support ship's side-scan sonar. Following these operations, the SKAT-GEO vehicle was used for several seasons in the Sea of Japan to monitor marine plant life underwater.

6000-Meter AUVs (L1 and L2)

In 1976 work was begun to develop an AUV capable of operation to 6000 m. Two prototypes were developed, L1 and L2. Initial testing of these systems was undertaken in 1979 with a full 6000 m test completed in December 1980. At this time a vehicle reached a depth of 5,930 m. These vehicles were used in operations in the Atlantic Ocean, the Pacific Ocean, and the Sea of Japan beginning in 1982.

AUV MT-88 and Prototypes

The AUV MT-88 (Fig. 1.6) has a traditional body configuration. It is composed of buoyancy blocks and fairings. The basic equipment is housed in 14 relatively small containers. The body is subdivided into several sections. This method of construction allows for easy modification since sections can be added or removed due to the modular type of construction. Main characteristics:

Rated water depth ................. 6000 m  
Maximal speed ........................ 1 m/sec  
Underwater endurance ................. 6 hours  
Mass ................................. 1 ton  
Overall dimensions ........ 3.8 x 1.15 x 1.1 m; .7 m in diam.  
Power source ............. silver-zinc battery, 16 cells, 100 A hours

A control station is placed on board the support ship containing a central computer, transceiver units of the acoustic positioning system (APS) and a communication link, recorder and other devices. This control station provides pre-launch AUV control and program input and displays AUV and ship movement in real time. An acoustic link allows modification of the vehicle's program. The computer also allows downloading and preliminary processing of data from the on-board vehicle storage devices after the AUV's recovery.

On-board vehicle subsystems share a common communication channel. This permits control instructions to be passed over a common electrical connection. These electrical connections can then be kept similar even when the vehicle is reconfigured to accomplish a different task. Program downloading prior to the vehicle's launch, data retrieval after its recovery, and vehicle operation in towed mode (pre-dive testing) are conducted over this communication channel .

The vehicle's descent and ascent are carried out by utilizing cast-iron ballasts. The AUV descends with two ballasts, one of them being thrown off when set water depth is reached, the other when the operation is over.

The propulsion system used in the vehicle consists of four main propulsors installed in the stern at an angle of about 20° relative to the vehicle longitudinal axis. By controlling motor rotation velocities a thrust vector can be generated in any desired direction, thus providing good vehicle maneuverability. Simplicity and homogeneity are also the system advantages. Instead of one velocity and two positional servo-systems (one propulsor with controlled velocity, two rudder turn gears), four identical velocity servo-systems are utilized. It is possible to use only three propulsors but some capability is sacrificed. Reverse is also provided for emergency cases. This capability was once successfully tested in a situation where the vehicle got hung up on a thin metallic object that was not detected by the onboard obstacle avoidance sonar.

Modular AUV construction has been used in IMTP designs since 1978. This technique allows for easy modification and reconfiguration to meet the needs of various mission tasks. Moreover, underwater devices of different kinds can be assembled easily. For example, a towed vehicle was designed, built, and used during at-sea operations. Thanks to the availability of standard elements these vehicles were built in a few months. Using this modular approach the institute has designed a number of standard components, chassis, functional units, electronic systems, sensors, hermetic connectors, and other devices which most AUVs must contain.

In 1989 initial tests were conducted to map manganese nodule deposits using the MT-88 in the Pacific Ocean. The operation was carried out on the Geolog Pjotr Antropov in cooperation with the international organization "Interoceanmetall." The goal of the operations was the determination of density and uniformity of nodule deposits in a defined area of the ocean. First, hydroacoustic profiling was performed by means of the AUV's side-scan sonar. Following this survey, the AUV conducted a photo survey over an area of 100 square kilometers. The survey tracks were determined during the first AUV dive such that the survey paths would take into account the direction of bottom currents. This survey was further complicated by the fact that the survey routes forced the AUV to transit "shadow zones" where the APS became ineffective.

The MT-88 prototype was used for search and inspection of two Soviet nuclear submarines that had sunk. The first submarine sank in the Sargasso Sea in 1986 at depth 5500 m and the second one Komsomolets in the Norway Sea in 1989.

The operation in the Sargasso Sea (January through April 1, 1987) was conducted using only the AUV. Although the weather conditions were severe, the AUV was launched up to sea state 4. The first 20 AUV dives utilized the onboard side-scan sonar to search for the sunken submarine. After its detection, 22 dives were undertaken to inspect the submarine. Over 40 thousand still pictures of the bottom were taken, 25 thousand of which were taken in the area of the sunken submarine.

To find the sunken submarine Komsomolets, a towed vehicle equipped with side-scan sonar and radiometer was used. This option was considered the better option since the water depth was 1650 m. On May 16, the submarine was detected and its location determined. Exact coordinates of the Komsomolets were transmitted to the scientific-research ship Mstislav Keldish; the manned vehicles Mir-1 and Mir-2 were then deployed.

As part of this effort, the AUV was used to gather photographic data of the sunken submarine. Survey conditions and appropriate survey paths were determined during the first five AUV dives. After this, 12 dives were conducted that allowed the AUV to gather about 150 still pictures that were then used to develop a mosaic of the area.

AUV Typhlonus

The accuracy of physical field measurements at abyssal depths during some oceanological missions (for example, fluctuations of current velocities) depends to a great extent on movements of the platform on which sensors are installed. To obtain satisfactory accuracy, platform velocity must be highly stable (vehicle velocity stabilization with an error not greater than fractions of 1 cm/sec). Other applications such as synthesis of acoustic array apertures or gravity measurements can be carried out only with minimal deviations in platform displacement or acceleration. The AUV Typhlonus, characterized by a long range and an improved stabilization system, has been developed to satisfy these requirements. The hull has a streamlined shape, though it is made up of modules similar to those used in the MT-88. Principal performance characteristics of Typhlonus:

Rated depth ...............2000 m  
Maximum velocity .............2 m/sec  
Mass .......................900 kg  
Overall dimensions ........ 0.8 m dia x 3.5 m  
Capacity of battery .... (27 V) 300 (600) Ah

Duration and range depend on the battery capacity and power of the user equipment. For 300 Ah battery and 30-150 W of power consumption, ranges are 230 and 140 km, respectively.

Although the goal of the Typhlonus vehicle was to implement a hull of extremely low drag resistance, the practicalities of using an AUV in real operations limit the design options. For these reasons, the Typhlonus hull is of more or less standard shape having small cylindrical insertion. Tests, both on the model and full-scale vehicles, indicated the hull resistance coefficient is 0.027-0.03 against V (where V=vehicle displacement) provided the Reynolds numbers begin at about 107.

Another important element of the vehicle hydrodynamic structure is the thruster. In Typhlonus, a single propeller was used to obtain high efficiency both for the thruster and motor. At the same time, to meet the demands of satisfactory maneuverability at low speed, a design was implemented that allowed the thruster axis to be moved both in the horizontal and vertical axes, thereby changing the direction of thrust. Design and testing of the Typhlonus suggested that the multi-thruster system is considerably simpler and more efficient with respect to vehicle maneuverability. The increased efficiency of a single propeller system is not obvious. The small hull resistance and resulting small thrust produced insufficient transverse forces with nominal vehicle velocity. As a result, foils were added to the turning section.

Tunnel Sea Lion AUV

In cooperation with a U.S. company, the institute developed an AUV focused on the inspection of long tunnels (Fig. 1.7). The initial design concept was to develop an autonomous vehicle; further considerations led to a "long range ROV," an AUV with an optical tether cable to allow inspection using a video camera. The original vehicle had a standard thruster system. Initial testing resulted in modifying that design to include water jets for thrusters. This eliminated the problem of the thrusters cutting the tether when it was backing up.

AUV CONTROL SYSTEMS

For the most part, all of the AUVs developed by the institute have some similarities in their control systems. The vehicles are controlled by an autopilot unit which interprets program commands, interacts with all the vehicle electronic units, reacts to telecontrol signals, and triggers pre-programmed commands in emergency situations. Information exchange between the vehicle systems is realized over the common communication channel.

The vehicle orientation control system is more or less traditional. The movement control in horizontal plane is carried out through a comparison of data taken from a flux-gate compass, and program course set by auto-pilot. To damp oscillations, a rate gyro is included in the feedback circuit. A control channel in the vertical plane has two operating modes -- auto depth or auto altitude. In the first case a programmed depth is compared with a depth-meter output; in the second, a feedback signal is produced by an echo-sounder. Signals from a pitch transducer and rate-gyro are also used. Transducer gains are chosen to achieve the optimal dynamic behavior of the control system.

Obstacle avoidance is implemented through the use of three sonar beams, one directed, one down, and one forward and at an angle of 45°. Obstacle avoidance is an integral part of the vertical plane controller. During bottom TV or photo surveys and detailed inspection tasks, the AUV moves at a pre-set distance from the bottom. The distance depends on the bottom relief, water clarity, bottom currents, and other environmental factors. This system has proven to be effective in most of the operations conducted, including those where the AUV was made to transit over large objects such as submarine hulls. The AUV MT-88 software is capable of including an improved adaptive control system with spatial obstacle avoidance. In the latest control system, a hybrid architecture, which is based on a hierarchy of network elements to increase the vehicle's survivability, is used. This is achieved in part by implementing a control system that is capable of reconfiguring itself. Some additional functions in software are directed at autonomous decision making.

Electronic hardware, naturally, went through several upgrades. In the mid-1980s a set of microprocessor boards, based on Russian CMOS ICs, were developed. These were used until recently. The latest modifications of the vehicles were implemented using WinSystems boards.

NAVIGATION SYSTEMS

A long base-line acoustic positioning system (APS) was designed for accurate positioning of the support ship and the vehicle with reference to bottom transponders. It is unique in that both the AUV and the support ship actively transmit synchronized sequences of acoustic pulses, thus allowing each to determine AUV position independently.

The vehicle on-board autonomous navigation system (BANS) includes a log, a compass, and a trim transducer and provides calculation of the vehicle location. Because of sensor errors, the precision of positioning goes down with time. In the MT-88 an Integrated Positioning System (IPS) has been implemented which integrates the BANS data with data from the APS. In the Typhlonus, two inertial navigation systems have been developed: simple strap-down system and precise inertial platform borrowed from space shuttle technology. They are being used to support gravity experiments and the measurement of the structure of acoustic fields.

SENSORS

Due to the modular structure of the vehicles, it is possible to install different measuring equipment easily. Nevertheless, a standard set of instruments is included on all AUVs. These include temperature/conductivity sensors, side-scanning sonar with tape recorders, and a still camera. Other transducers such as gamma-radiometer and magnetometers are included when they are needed. Currently, work is underway to include a sensor for gravity measurements.

A NEW CONCEPT: THE SOLAR POWERED AUV

The institute at the present time is working on a solar- and wave-powered cruising AUV with unlimited range. The institute is currently conducting a number of investigations into various subsystems. Initial results suggest that a vehicle 1.2 m long, .5 m wide, and .22 m in depth weighing from 20-50 kg with an optimal speed of 2 knots would allow 50 km transits during the nighttime hours. More work must be completed.

IMTP HYDROSTATIC TEST FACILITY

The entire panel visited the IMTP hydrostatic test facility and storage building. Older versions of AUVs developed at the institute, some no longer in use, were stored there. The hydro test chamber is unique in its test depth of 15 km (49,200 feet or 21,900 psi). The vertical chamber is .5 m in ID and will accept test articles up to 1.5 m in length. This allows IMTP to test all new pressure vessels to failure for validation of designs. In addition, all pressure vessels to be used in IMTP's AUVs are cycled to test depth before use. Originally, a single penetrator through the top allowed instrumentation of test articles. Over the years, the need for instrumentation has been reduced by the standardization of pressure vessels, and now simple go-no go tests are mostly conducted. Features of the facility include the following:

During our visit to the IMTP test facility we observed two vehicles of older construction that are now not in use. The L2, built in 1980, is an early AUV that has made numerous dives during its useful life. These at-sea operations included over 160 dives to depths greater than 4.5 km. L2 was used to search for sunken Russian submarines in the Bay of Biscay at 4.5 km off Bermuda in 5.5 km and the Komsomolets off Norway in 1.7 km. A typical operation includes about one hour for descent, six hours of bottom time, and one hour of ascent.

The other UV observed was a towed device that was used in the initial location of the Komsomolets in 1989. Two of these towed vehicles were manufactured and assembled on board the support ship while underway to a deep water search operation. The two towed systems were made of modular components developed for the AUV systems. While the team was at the institute, Dr. Ageev was asked to describe a few research issues that he felt were important at this time. The following research problems were identified:

  1. The use of AUVs for marine gravity surveys (an extension of the Typhlonus project) and an experimental study and optimization of the control system to achieve very high motion stability, hence precise gravity measurement
  2. Further development of integrated navigation systems for AUVs, including the use of sonar and video images
  3. Investigations into long range/ long duration AUVs powered by solar and wave energy: energy, actuators, reliability, survivability
  4. Development of intelligent control systems for AUVs tasked to accomplish real world tasks: survey and inspection of long, water-filled tunnels, underwater pipelines, and cables
  5. Investigations of basic issues associated with deep diving (11 km) AUVs

REFERENCES

List of Selected IMTP Publications on AUV

Ageev, M. D., B. A. Kasatlin, L. V. Kiselyov, et al. 1991. Unmanned Free Submersibles. Leningrad. Sudostroenie, 224p., ill. ISBN (in Russian) .

Ageev, M. D. 1991. "The use of autonomous unmanned vehicles in deep-sea operations." Undersea World '91, USA.

Ageev, M. D., L. V. Kiselyov, and A. Ph. Scherbatyuk. 1991. "Tasks for autonomous underwater robots." ICAR ' 91, Pisa, Italia.

Ageev, M. D. 1991. "Autonomous underwater vehicles of the Institute of Marine Technology Problems." In: Proc. of the 4th Pacific Congress on Marine Sciences and Technology. Tokyo, Japan.

Ageev, M. D. 1992. "Propulsion plant for highly manoeuverable AUV." Proc. Intervention '92 Conf., San Diego, California. pp. 394-401.

Ageev, M. D. 1993. "Propulsion plant of minimal composition for highly-manoeuverable AUV." Underwater Intervention '93 Conference Proceedings, New Orleans, Louisiana.

Ageev, M. D. 1994. "Thruster equations for arbitrary regime of AUV/ROV motion." Underwater Intervention '94 Conference Proceedings, San Diego.

Ageev, M. D. and N. I. Rylov. 1989. "Vehicle induced errors by current fluctuations measurement." Proc. Intervention Conf., 1989, San Diego, California. pp. 128-132.

Ageev, M. D., L. V. Kiselyov, and A. Ph. Scherbatyuk. 1990. "Integrated positioning system of underwater robot." Proc. Intervention '90 Conf., Vancouver, Canada. pp. 228-232.

Ageev, M. D. 1990. "The use of autonomous unmanned vehicles for deep water search operations." Subnotes, Sept/Oct. pp. 10-11.

Dorokhin, C. A., and Toropanov V. V. 1990. "Simulator for hydroacoustic navigation system." Black Sea '90 Conference Proceedings. pp. 184-188.

Inzartsev, A. V., Kiselyov I. V., and Lyvov O. Yu. 1990. "Underwater robot motion adaptive control." PACON '90, Tokyo.

Krasovsky, V. P., Evtusllenlo V. V., and Savostin S. V. 1990. "Underwater TV robot." The 1st Soviet-Chinese Symposium on Oceanography, Vladivostok. pp. 90-91.

Nikiforov, V.V. 1990. "Underwater robot in the purpose of investigation of spatial variability of nodule-bearing ocean region resources." The 1st Soviet-Chinese Symposium on Oceanography, Vladivostok. pp. 89-90.

Scherbatyuk, A. Ph., and Yu. V. Vaulin. 1990. "Simulation of the integrated navigation system for the autonomous underwater vehicle." Black Sea '90 Conference Proceedings. pp. 198-201.

Scherbatyuk, A. Ph. 1993. "A side-scan sonar image processing system for the survey of pipeline." Underwater Intervention '93 Conference Proceedings, New Orleans, Louisiana. pp. 68-75.

Papers Presented For Oceans '94 Conference

Ageev, M. D. "AUV -- a precise platform for underwater gravity measurement."

Inzartsev, A. V. "Planning and execution of mission for inspecting AUV."

Inzartsev, A. V., O. Yu. Lyvov, and A. V. Sidorenko. "Control system architecture of search and surveillance AUV."

Kasatkin, B. A., Ju. G. Larionov, Ju. V. Matvienko. "Development of deep-water array for sub-bottom profiler."

Kiseljov, L. V., and D. B. Khmelkov. "Dynamical properties of AUV Typhlonus motion control system."

Scherbatyuk, A. Ph., and Y. V. Vaulin. "Integrated positioning system for underwater autonomous vehicle MT - 88."


Published: August 1996; WTEC Hyper-Librarian