Institute of Marine Technology Problems of the Far-Eastern Branch of the Russian Academy of Sciences

An autonomous underwater vehicle (AUV) positioning method using the range data from one transponder of a long base line acoustic positioning system and the yaw and relative velocity information from an on board autonomous navigation system is described in the paper. The localization algorithm is based on the least squares root method. The algorithm allows one to calculate the AUV position and current velocity estimations. The simulation results of the method are supplemented.

Abstract The problem of robust linear and nonlinear diagnostic observer design is considered. A method is suggested to construct the observers that are disturbance decoupled or have minimal sensitivity to the disturbances. The method is based on a logic-dynamic approach which allows us to consider systems with non-differentiable nonlinearities in the state equations by methods of linear algebra.

The paper focuses upon framework design with distributed computing for real-time simulation of resource-intensive tasks connected with testing of autonomous underwater vehicles' (AUVs') “intelligent” control algorithms. Algorithm research is carried out by simulation of a wide range of onboard sensors, AUV dynamics, and underwater physics. A distinctive feature of the simulator is the possibility of testing algorithms directly in a selected AUV control system environment. The simulation framework architecture utilizes client-server technology and a centralized database with the possibility of connecting both personal computers and supercomputers as computational nodes. The modular approach utilized provides the possibility to expand the algorithm and functional base by connecting additional modules via plug-in technology. The framework's functional capabilities, modules' interaction diagram under the circumstances of distributed computing, data communications, and storage protocols taking into account specific features of the simulated processes are described. The framework testing results with different computational configurations illustrating the possibility of performing real-time simulations of AUV control processes with heavy computational loads are quoted.

Autonomous underwater robotic vehicles (AUVs) are equipped with monitoring and emergency systems (MESs) to increase the mission success rate. The MES ensures the AUV's safety in water and the fault tolerance of its subsystems. The signals produced by the self-test functionality of robot subsystems as well as the parameters measured by sensors are the source information for the MES. Nowadays, MES actions in the AUVs designed by the Institute for Marine Technology Problems (IMTP) are based upon the hypothesis of the isolation of signals. As a result, the robot's reaction to several quasi-simultaneous signals is not always adequate. It is possible to overcome the disadvantages of the existing version of MES with the help of an ontological approach to be used for the implementation of an intelligent MES (IMES). An IMES functions as a tactic-level agent of the information and control system can carry out diagnostic actions (submissions) if necessary. The compiler forms the IMES with the help of a preset knowledge base and description of the robotic configuration with the application of the cloud platform IACPaaS. Knowledge is a semantic network. The architecture of the AUV's IMES consists of three basic blocks: a block for the formation of knowledge on AUV fault diagnostics, a translator that translates knowledge into program code, and the AUV MES itself. Extensive testing of IMES as part of AUV is planned soon.

In July of 1997, a cooperative research program was begun between the Autonomous Undersea Systems Institute and the Institute for Marine Technology Problems (IMTP), Russian Academy of Sciences, Far Eastern Branch, in Vladivostok. In January of 1998, The Office of Naval Research NICOP program funded a joint proposal to evaluate the technologies required for a solar-powered AUV. One of the products of this program was the development, fabrication and testing of a solar AUV engineering prototype. The 90 kg vehicle is 1.7 meters in length, 0.7 meter wide with a pressure case diameter of 0.24 meters. It has two Solarex (MSX30L.) 30 watt solar panels and 32 Ni-Cd cells in a four battery (8 cells in series) configuration. The onboard computer system controls all vehicle functions and records engineering data. This prototype system has undergone sea testing near Vladivostok, Russia. 48 runs were executed during 22 working days with the objective of defining performance of the vehicle and verifying its ability to function as a moving platform for long endurance measurements in the ocean. The calculated motion characteristics of the vehicle were compared with calculated ones. Also the properties of vehicle behavior in conditions unique to the SAUV such as sea keeping during drifting or moving on the surface were considered. On the whole, the test results are very positive. These test results are discussed.

This article presents the results of marine trials carried out in the framework of the project of the development of hydro acoustical communication system for AUV (Autonomous Underwater Vehicle) and ASV (Autonomous Surface Vehicle) group control and navigation. Specificity of the application imposes special requirements on the developing Underwater Acoustic Communication System (UACS). When communicating with the non-stationary AUV, the instability of the underwater acoustic channel parameters, the low predictability of the reverberation level and the stochastic time distribution of impulse noises generated by biological objects are observed. In these circumstances, it is necessary to use the communication system a priori resistant to any possible disturbances.

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.

The problem of fault diagnosis in technical systems described by linear dynamic models is considered. The approach allowing increase robustness of the diagnostic process under disturbances is suggested. The approach includes two stages: (1) synthesis of sliding mode observer, sensitive to the disturbance and invariant with respect to the fault; this observer estimates the value of the disturbance, (2) synthesis of diagnostic observer, sensitive to the fault, using the estimated value of the disturbance giving by the first observer to compensate the effect of the disturbance; this observer provides fault detection. To isolate faults, the complex diagnostic tools are constructed.

This paper considers an approach to creation of reliable dead reckoning system (DRS) for autonomous underwater vehicle (AUV) with accommodation to incorrect sensors information. Proposed DRS is based on using of diagnostic observers built with the help of kinematic model of AUV and special navigation data fusion. The proposed system advantage consists in the relative simplicity of implementation and high accuracy compensation of errors detected in the navigation sensor data. Results of marine trials using the AUV MARC are presented in the paper.

The paper is devoted to the problem of increasing the efficiency of underwater vehicles by using a fault diagnosis system for their thrusters which provides detection, isolation, and identification of minor faults. To address the problem, a two-stage method is proposed. At the first stage, a bank of diagnostic observers is designed to detect and isolate the emerging faults. Each observer in this bank is constructed to be sensitive to some set of faults and insensitive to others. At the second stage, additional observers working in sliding mode are synthesized in order to accurately estimate the error value in the signal obtained from the angular velocity sensor and to estimate deviations of the thruster parameters from their nominal values due to the faults. In contrast to the existing solutions, reduced-order (i.e., lower-dimensional) models of the original system are proposed as a basis to construct sliding mode observers. This approach permits reduction of the complexity of the obtained observers in comparison with the known methods, where full-order observers are constructed. The simulation results show the efficiency and high quality of all synthesized observers. In all cases considered, it was possible to detect typical faults, as well as estimate their values.

Abstract 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.

Consideration was given to construction of the robust linear and nonlinear diagnostic observers. A method was proposed to construct nonlinear diagnostic observers insensitive or minimally sensitive to disturbances. The distinction of this method lies in that in some cases it is possible to do without enumeration of the solution variants characteristic of other methods. The method was realized using the logic-dynamic approach.

Abstract 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 article describes the features and results of using the autonomous underwater vehicle (AUV) MMT-3000 for research of Antarctic ecosystems and deep-sea biological resources of the South Seas. The methodology for working with an AUV in the extreme conditions of Antarctica and the technical solutions used to visually assess the distribution of bottom animals are discussed. The results of processing the data obtained by AUV during deep-sea missions in the Atlantic sector of the Antarctic during the expedition of the RV Akademik Mstislav Keldysh (cruise 79) in 2020 are presented. At the same time, the data of image analysis and trawl catch were compared. Based on the experience gained, the requirements to be implemented in the new AUV MMT-3500, which is designed and manufactured to effectively carry out deep-sea research in subsequent expeditions in the Southern Ocean, are determined.

The problem of functional diagnosis of technical systems described by linear dynamic models under disturbances is considered. For solving the problems of detection, isolation and identification of faults, a method based on sliding mode observers is used. Modifications of this method for relaxing the implementation constraints in comparison with the well-known results and also for reducing the complexity of diagnostic tools are proposed.

Redundancy Relations for Fault Diagnosis in Nonlinear Uncertain Systems The problem of fault detection and isolation in nonlinear uncertain systems is studied within the scope of the analytical redundancy concept. The problem solution involves checking the redundancy relations existing among measured system inputs and outputs. A novel method is proposed for constructing redundancy relations based on system models described by differential equations whose right-hand sides are polynomials. The method involves a nonlinear transformation of the initial system model into a strict feedback form. Algebraic and geometric tools are used for this transformation. The features of the method are made particular for uncertain systems with a linear structure.

This paper deals with the design principles and implementation of a reconfigurable real-time software platform designed for data exchange between software modules of unmanned underwater and surface vehicles. The aim of developing a new robotic platform was the realization of a light-weight OS-independent library that allows integrating AUVs, ROVs and surface vehicles to a single computing cluster. The advantage of the developed system is the possibility of information interaction through the low-speed and unstable acoustic channel. It should be noted that the developed platform does not require any additional tools or software modules in the robot control system. All that is needed is a single library for inter-process communication, data logging and web-based graphical user interface. The developed system is used in several autonomous and remotely operated underwater vehicles, designed at the Institute for Marine Technology Problems and Far Eastern Federal University. The graphical user interface of this platform is based on the mechanism of web sockets and is compatible with the Robot Operating System.

The accuracy estimation of positioning system operation for autonomous underwater vehicle (AUV) based on using of single hydro acoustic beacon transported by autonomous surface vehicle (ASV) is discussed. The accuracy research is performed for two navigation algorithms which used information about distance to a single mobile beacon and data from the AUV onboard reckoning system. The first algorithm is based on the implementation of the extended Kalman filter for estimating the AUV location and the second algorithm involves usage of particle filter on board of the AUV. The method for accuracy estimation is described and some results of the marine trials using robotic complex MARC with AUV and ASV are supplemented.

1. Limites do problema. 2. A retroatividade nas situações protegidas.3. Retroatividade na má aplicação da lei. 4. Eficácia retroativa eefeitos duvidosos. 5. Conseqüências lógicas e jurídicas. 6. Determinaçãodos efeitos sobre o passado. 7. O valor de juízo na interpretação.8. Ato novo na retroatividade. 9. A retroatividade na revogação.10. A retroatividade na anulação. 11. Tutela administrativa e retroatividade.

The problem of fault diagnosis in thrusters of autonomous underwater vehicle is studied. Solution of the problem involves residual generation as a result of mismatch between vehicle behaviour and its reference model behaviour followed by decision making via evaluation of the residual. Sensitivity theory based methods are developed for the design of both residual generator and decision making procedure. These methods are applied to the model of CR-01 autonomous underwater vehicle. Appropriate simulation results are given.