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Developing multi-purpose AUV with through-body thrusters capable of undertaking both survey-style missions and low-speed interaction requires sophisticated thruster allocation algorithms. The paper presents the adaptive optimal allocation method. This method allows a smooth transition between different motion styles by exponentially decreasing through-body thrusters’ involvement according to their hydrodynamic model. The proposed method is compared with the prioritized direct allocation method. The simulation result of the control allocation for the AUV “MMT-300” propulsion system model is provided.

AUV’s actuators systems are highly affected by external conditions such as incoming flow velocity. The paper aims to estimation of incoming flow velocity based on quasi-steady model of thruster. The work motivation is compensation of incoming flow effect on AUV’s actuators dynamic model for improving actuator control or a velocity estimation in case of velocity sensors absence. The equation for incoming flow velocity estimation is presented. It accounts orientation of thrusters relative to the longitudinal vehicle axis. Thruster parameters identification procedure based on bollard pull tests and marine trials are presented. Comparative results of propulsion-based velocity estimation with DVL data are discussed. Velocity estimation error between methods is less than 0.1 m/s in steady motion and less than 0.2 m/s in transition process.

The authors propose a new modular design of an underwater vehicle in the article. The core idea is the complete separation of an underwater vehicle on different self-sustaining modules with its control and power system. It is proposed that wireless technology will provide data and power transfer between modules. The approach might be useful for design low-cost underwater vehicles for surveying in shallow water (up to 100 meter depth) with different replaceable payload modules. The paper presents the principal design of modules and their joint. The communication system's design based on Bluetooth Mesh is presented. The experiment shows reliable data transmission up to 35mm in seawater and up to 100mm in seawater with plastic supports between module housings. The power management system is presented and discussed in the paper. The paper presents its overall design and the wireless power transfer system as the most critical node. The last one aims to unite batteries of all vehicle modules in the one “virtual” battery. It is shown that power transfer efficiency is up to 84% on distance 10mm between planar coils due to implementing the magnetic resonance method.

The report presents a comparative analysis of various control allocation methods by taking into account an over-actuated propulsion system and actuator constraints for autonomous underwater vehicles. Comparing methods by the size of a feasible control region, compute time, consumed power, and control error is presented. It is shown that the choice of an allocation method significantly affects the quality of control of an underwater vehicle and consumed power during maneuvers.

During Remotely Operated vehicles (ROVs) work it is often required surveying shipwrecks and sunken aircrafts and its inner condition as well as different types of narrow underwater tunnels and caves that requires wide pitch and roll angles of the vehicle to be controlled. A classical ROV has high stability and unable to work in such conditions. Thus, it is necessary to design the new type of high maneuverable ROV that provides effective working within limited space. The new small-sized ROV is presented in the article. The vehicle gives effective motion control within a wide range of pitch and roll orientation. The main feature of the vehicle is the Variable Center of Gravity (VCG) system. The article contains overview of the hydrostatic model for the vehicle with the variable center of gravity. The design of the vehicle and its systems are presented in the article. In-situ ROV poll test in water pool are presented.

Traditionally, bottom magnetic surveying is performed on towing the magnetometer by the ship with considerable length of the communication cable. This method is high costed and has significant limitations due to risks of equipment loss at poor weather conditions. At the same time, the magnetic field created by on-board equipments excludes possibility of installing a precision magnetometer in an underwater vehicle. To achieve the maximum accuracy of the magnetic survey, it is required to tow the measuring equipment at some distance from the vehicle, depending on its length. The article shows study results of effect of the towed magnetometer on the motion parameters of an autonomous underwater vehicle. The method developed by the authors for calculating the effect of towed equipment on the vehicle in cruising and maneuvering modes along standard trajectories is presented. The mathematical model of disturbances by towing of a magnetometer is determined. This model is based on an analytical representation of simulation results of steady-state motion. The structure of vehicle motion controller proposed in the article allows perturbations from a towed equipment to be effectively compensated. The simulation results of the underwater vehicle motion with a towed magnetometer are proposed. The usefulness of the method presented in the work was confirmed during the conduct preliminary magnetic survey of the area for underwater fiber-optic connection line in the Sea of Okhotsk.

Remotely operated underwater vehicles (ROVs) are widely used in underwater operations, from research and survey operations to complex underwater technical and rescue ones. But the connectedness of an ROV and a carrier vessel imposes restrictions on the ROV and vessel’s joint motion. The article aims to present the concept design of an unmanned surface vehicle for an observation-class ROV. The surface vehicle allows breaking wired connections between the carrier vessel and the ROV by a wireless communication system based on Wi-Fi technology. The detailed design of the unmanned surface vehicle and its main systems are presented in the article.

The towed surface radio communication module (SRCM) allows the high-speed communication channel between the control station and an autonomous underwater vehicle (AUV) to be organized and significantly simplifies the navigation support. Herewith, disturbances by the communication cable acting on the SRCM and AUV are significantly affecting the whole system’s parameters. The paper aims to calculate the additional drag force acted on the vehicle by affecting the towed SRCM and communication cable on the AUV in steady conditions and along typical maneuvering trajectories. A model of an underwater tethered motion control system considers the AUV dynamics, and the communication cable is proposed. A kinematic model of the SRCM has been developed. This model determines the submerging of the communication module and hydrodynamic resistance during towing. The paper presents the results of modeling the tethered system’s movement along typical trajectories typical for survey-search AUV. The results allow the additional requirements to the vehicle’s propulsion system and the required additional buoyancy of the SRCM to be obtained.

Periodic cleaning of a hull from biofouling provides high efficiency motion of a vessel. Inspection and cleaning of the underwater part of the vessel afloat is usually carried out by divers aimed with an underwater video system, non-destructive devices for hull structures monitoring, as well as tools for cleaning surfaces from biological fouling and corrosion products. The aim of the study was to develop a new technical tool for remote survey and cleaning of vessels based on the remotely operated uninhabited underwater vehicle (ROV) with build-in underwater laser cleaning equipment. As a result of the research, the prototype of an underwater robotic inspection and laser cleaning system for vessels afloat was designed and developed. The experimental results of the motion control system of the ROV with a hybrid propulsion system both in air and under water are presented. The efficiency of the laser cleaning equipment in stand-alone mode and as part of the vehicle was confirmed. The technical solutions obtained during the development of presented cleaning system allow efficiently and safely inspecting and cleaning the hull without docking of the vessel to be conducted.

The robotic complex for long-term mobile aqua monitoring is presented in this article. The complex consists of the underwater vehicle and the surface repeater. The main feature of the vehicle is a variable buoyancy system. The system allows buoyancy of the vehicle to be controlled in the wide range. We tried to combine mobility of classic AUVs and energy efficiency of static buoys. The technical implementation of the robotic complex and models of its using are presented. The results of the energy efficient hybrid method of depth control with the propulsion system and the VBS (Variable Buoyancy System) and long-term depth scanning by means of the VBS are showed.

At present the important tasks are to study the biological productivity of sea water, to conduct environmental monitoring of the sea pollution and to search for minerals. The sampler device included in the underwater mobile robotic complex is considered in this paper. The device is intended for the real time determination of the chemical composition of water and bottom sediments. The complex makes it possible to carry out the qualitative and quantitative measurements of the concentration of substances dissolved in water by laser induced breakdown spectroscopy using nanosecond laser pulses.

Autonomous Unmanned Underwater Vehicles (AUV) equipped with side-scan sonars (SSS) and photo systems may be used for automatic detection and inspection of local bottom objects. SSS allows efficient identification of bottom objects at a considerable distance, while photo the system is used for detailed registration of object states in the short-range zone. To carry out monitoring, both scenarios assume the use of a single multi-purpose AUV (cycling through the stages of detection and photo survey) and a group of special-purpose AUVs simultaneously performing these missions is possible. Online detection of predetermined objects on acoustic images is carried out with the help of algorithms. They include: gradient field mapping, objects boundaries detection, and detection of the objects themselves by means of clustering procedures. Then the objects meeting preset characteristics shall be chosen and their coordinates determined. The coordinates obtained are used for arrangement of AUV approaching the object detected and carrying out its photo coverage. This paper focuses on model simulation of monitoring tasks, including investigation of object identification algorithms and AUV control in case of a single and group application. The results of experiments that confirmed the possibility for application of the developed algorithms during real operations are discussed.

Manifold AUV uses are viewed on the basis of the idea of ocean physical fields. An example is the problem of trajectory survey of the seabed field and navigation according to the bathymetric map. Application of known methods to the problems of AUV motion control runs into certain difficulties with regard to investigation of poorly known ocean areas. In this case representation of the field map does not define source data for control system, but defines the final goal of survey. Trajectory survey of physical fields of the ocean is based upon evaluating of state vector of an underwater vehicle and formulation of generalized reference points. Whereby search algorithm handles data about control field reducing the control problem to implementation and correction of program trajectory. An example would be organization of motion by bathymetric contour of seabed field. Information for control is produced on the basis of seabed profile measurements in longitudinal and lateral directions. Control algorithm simultaneously stabilizes depth and distance to the bottom, works out a course program and corrects it with provision for probable navigation errors. When organizing searching trajectories specific features of anomaly structure, including presence of natural background, time and spatial disturbances shall be taken into account. The control goal in the anomaly field consists in profiling of the area of certain range within searching zone. In general case several possible variants may exist. They differ on the type of motion trajectory and correction method when pointing at the anomaly source. In case of receipt of incomplete or unreliable information fuzzy logic is used for the modes of program trajectory correction. Motion control in all variants assumes combination of course correction with coordinate determination of anomaly feature points. A complex bathymetry problem is an indicative one among other certain problems. It includes search for local survey area, seabed mapping and profiling of anomaly area (bathymetric contour motion). The paper analyzes possible approaches to such and other similar problems addressing.

Autonomous Underwater Vehicles (AUVs) are widespread and effective tool for oceanographic research. The main applications of AUVs are long-term missions for survey of wide area and patrolling. However the key issue for long term cruising range is energy storage. One of approaches to reduce energy consumption is using of the variable buoyancy system (VBS) on the AUV. This approach allows to compensate AUV's buoyancy and to reduce energy on hovering due to it. Two combined depth control methods based on cooperative work of propulsion system and variable buoyancy system has been presented in this paper. Estimation of the methods based on calculation of energy consumption and transient response time has been made. Comparison of ones with methods based on standalone work of propulsion system and VBS has been made. Provided methods was proved on simulation and water pool tests on variable buoyancy AUV “CH-2” designed at Institute of Marine Technology Problems FEB RAS year ago.

This paper presents the development of the new small-sized high-maneuverable remotely operated vehicle. The main scope of the vehicle is survey of shipwrecks. The main feature of the vehicle is variable restoring moment achieved by the rotated ring with the ballast in the transverse plane of the vehicle. This feature augmented with low value of own restoring moment and the overactuated propulsion system consisting of four vehicle and four horizontal thrusters allows high range of maneuverability to be achieved. The vehicle is equipped with the built-in lithium-ion battery. This feature reduces tether weight and allows automatic emergency return functions of the vehicle to the coast station in the case of cable damage to be implemented. The design rationale of the vehicle and the systems integration diagram are presented in the article. The design rationale of the variable restoring moment mechanism is described. The software based on modern development of Institute of Marine Technology problem FEB RAS and Far Eastern Federal University are presented.

The survey of an underwater part of ships is the mandatory procedure by rules of the Russian Maritime Register of Shipping. Periodic cleaning of the ship’s hull from biofouling increases efficiency of its motion. Inspection of the underwater part of the ship during afloat is currently carried out by divers with the underwater video system, devices for non-destructive testing of hull structures, and tools for cleaning surfaces from products of biological fouling and corrosion. The purpose of this study was to develop a new technical tool for remote surveying and cleaning of ship’s hull using a remotely operated vehicle (ROV) equipped with underwater laser cleaning equipment. The design of the vehicle for inspection and laser cleaning of ships has been developed during the research. The algorithms for trajectory controlling of the vehicle over the hull surface based on wheel and propulsion system has been proposed. The navigation data for the trajectory planning was received from combination of wheel and visual odometry. The proposed technical solutions allow the hull of the ship to be inspected and cleaned effectively and safely without being placed in the dry dock as well as to quickly assess the condition of the surface with the binding of the results to the ship’s drawing.

The perineural net (PNN) is responsible for synaptic stabilization of adult brain. It plays an important role in brain signal processing and non-synaptic signal transfer as well [ 1]. Since it is composed of largely negatively charged chains of disaccharides, it can be easily affected by strong external electromagnetic field irradiated by high-energy particles passing brain tissues. One of the effects of such exposure is a cognitive impairment. Since outside of the Bragg peak area local electromagnetic field irradiation strong enough to affect on the PNN's dynamics, it is very important to understand PNN's behavior in locally strong electromagnetic fields. The presented work is devoted to PNN modeling in field theory framework. As a toy model of PNN, we consider fractal lattice with Ising and XY model applied. More precise study requires application of the quantum electrodynamics on the lattice. We study how local excitations can change phase state of the overall lattice and its finite clusters. For this propose, the partition function of the Ising model is calculated using Monte Carlo simulation [ 2]. The two-dimensional Serpinsky Carpet lattice is applied to approximate structure of the brain extracellular matrix. Order parameter is calculated for different levels of the self-similarity of the Serpinsky Carpet. It is shown that starting from the level = 3, the lattice with fractal structure has irreversible phase transition: phase state after restoration differs from the initial one. In Fig. 1, the calculation of the correlation length change due to the energy dissipation after a local impact is shown. The column shows correlation strength (from 0 to 1), the right axis shows the cluster size ratio to the whole lattice size in percentage. The initial lattice was totally correlated (100% of the lattice has correlation strength that equals 1). The left side of the picture corresponds the locally excited lattice with no correlation, the right side of the picture corresponds the lattice after the relaxation to the equilibrium state due to the energy dissipation. It can be clearly seen that the lattice is not correlated after the relaxation. Fig. 1. Correlation length change due to the energy dissipation. Conclusions Local impact changes the correlation length of the fractal lattice: after the restoration, the correlation length becomes short, thus signal processing on the lattice changes significantly. Thus, it can be considered as a good model to study of the extracellular matrix change due to local excitations of strong electromagnetic field.