Navigation Equipment Research Articles

Development of a 6-degrees-of-freedom measurement system using a robotic total station for a free-running model test

The measurement of a model ship's six degrees of freedom (6-DOF) using sensors such as Marvelmind beacons and robotic total stations (RTS) has previously demonstrated substantial error margins. To address these limitations, this study introduces a refined approach for accurate and reliable 6-DOF measurement through free-running model tests (FRMT). The tests were meticulously designed, with three RTS strategically positioned to meet the specific requirements of the measurement scenario. Given the potential constraints in an FRMT environment, we proposed feasible installation ranges for the RTS and prisms, ensuring the stable measurement of the model ship's 6-DOF. To achieve high-precision motion measurement, even in complex environments, we employed the prism queue algorithm, which identifies and processes overlapping or untracked prisms monitored by the RTS. The proposed methodology was validated through simulations and FRMT conducted in the ocean engineering basin of the Korea Research Institute of Ships and Ocean Engineering and by developing an actual implementation program. Comparative analysis using high-precision navigation equipment, such as fiber optic gyros, demonstrated that the method provided unbiased and stable data. Consequently, the proposed method shows significant promise as a viable alternative for precision navigation in real-world applications.

Study of Systems of Active Vibration Protection of Navigation Instrument Equipment

Assessment of the influence of vibration isolator parameters on the distribution of the system’s natural frequencies is a significant task in the design of vibration isolation systems. The root method was used to determine the natural frequencies of the controlled vibration isolator. For a certain feedback structure of a controlled electrodynamic type vibration isolator, the need for a consistent selection of parameters has been justified. A mathematical solution has been proposed for the approximate determination of the roots of the characteristic equation of the controlled vibration isolator, which enables the analytical assessment of the influence of the vibration isolator parameters on the distribution of its natural frequencies. The research has been conducted in relative parameters, which makes it possible to generalize the results. The specificity of the inertial dynamic vibration isolator, which in some cases is associated with the implementation of anti-resonance conditions, can lead to the fact that resonant frequencies can occur on both sides of the tuning frequency of the vibration isolator. The use of an elastic suspension on flat springs to protect navigation equipment from vibration allows reduction in the intensity of translational vibration, while not changing the orientation of the device relative to the Earth. The implementation of an elastic suspension according to the scheme of the inverted pendulum allows an increase in the effectiveness of vibration isolation, under the conditions of a controlled change of the vibration isolator parameters and due to the use of feedback. The results of this research can be used in precision systems, such as vibration isolators, laser processing equipment, ultraprecision measurements or medical devices.

GNSS/INS integrated navigation algorithm framework based on cascade vector tracking algorithm for USV

The safety of Unmanned Surface Vehicle during the autonomous phase of navigation relies heavily on the onboard navigation equipment. However, in the face of changing and diverse navigation environments, global satellite navigation systems utilizing radio communication often face signal occlusions. This significantly reduces the positioning accuracy of navigation systems. To ensure the navigation accuracy of vehicles in various harsh environments, a Global Navigation Satellite Systems and Inertial Navigation System (GNSS/INS) integrated navigation system structure based on cascaded vector-tracking loop is proposed in this paper. The integrated navigation scheme not only improved the positioning accuracy of the navigation system but also effectively improved the robustness of the system. Compared with the traditional scalar-tracking loop and vector-tracking loop methods, it exhibits better performance. The experimental results show that the proposed method can reduce the horizontal position positioning error by 73.7% compared with the traditional vector-tracking loop method in the case of signal occlusion. Simultaneously, it can continuously output reliable and high-precision positioning information in the case of serious signal occlusion. The integrated navigation scheme proposed in this paper can be used as a research direction for the development of Unmanned Surface Vehicle navigation applications and provides solutions for the development of related navigation systems.

An integrated decision support system for ship collision avoidance

The ship encounter process is divided into the stages of free action, risk of collision, close-quarter, and immediate danger according to the four-stage theory of ship encounters. Current research on ship collision avoidance primarily focuses on the risk of collision stage, aiming to prevent ships from entering the close-quarter stage. However, various navigational equipment and environmental factors may cause ships to enter the close-quarter or immediate danger stages. Therefore, this paper establishes an integrated decision support system for the above stages to ensure that ships can handle all situations. First, the system includes a new collision risk detection module based on the ship domain model and the four-stage theory. Subsequently, in the collision avoidance strategy formulation module, two sets of avoidance strategies are established based on the convention on the COLREGs and the most effective avoidance principle for ships in different stages. Finally, in the avoidance action optimization module, a new fitness function is constructed based on ship maneuverability, and the sparrow search algorithm is introduced to solve for the optimal avoidance actions. The results demonstrate the capability of the decision support system presented in this paper to effectively avoid other ships in different stages of the encounter process.

Optimization of Prevention of Hazards MV. Meratus Kariangau Ship Running Across Entering the Narrow Waterflow of the Barito River

This research aims to Optimize the Prevention of the Occurrence of Shipwreck Hazard of MV Meratus Kariangau when Entering the Narrow Shipping Channel of the Barito River. This research method uses a qualitative method with a descriptive approach. For primary data collection techniques obtained from the results of interviews and observations, while for secondary data collection techniques obtained from tidal data in the Barito river, then from journals related to this research, books and others. The results of this study indicate are a). Indication of overdraft when entering the narrow shipping channel, b). Lack of attention to UKC and Tidal Tables, c). Human error from the watch officer who did not pay attention to the tide list. Preparations that must be made by the MV. Meratus Kariangau before entering the narrow shipping channel of the Barito river to avoid the danger of running aground are a) The duty officer and the skipper must operate the navigation equipment on the ship, for example Radar, Echo sounder, GPS. b) The duty officer prepares a map of the narrow shipping channel to be passed. c) The duty officer asks the Engine Control Room (ECR) to ensure that the engine is ready to pass through the narrow shipping channel d) The duty officer calculates the UKC and Squat on the shipping channel to be passed e) The crew conducts a grounding drill to know their duties and responsibilities when running aground f) The skipper and duty officer apply P2TL rule 9 on Narrow channel.

Dry Bulk Loading and Unloading Services at JIIPE Gresik Port

The aim of this thesis research is to understand loading and unloading services and the obstacles faced as well as efforts to minimize these obstacles. The method used is a qualitative research method, where the method is obtained from data based on information or surrounding phenomena in the form of in-depth observations and interviews. The results of this research explain dry bulk loading and unloading services with the procedures and service procedures that apply at JIIPE port. The obstacles faced and efforts to minimize these obstacles are 1) obstacles from waiting for trucks are carried out by coordinating with the truck fleet owner or with the owner of the goods so that there is no waiting time for trucks. 2) obstacles to equipment damage are carried out by means of regular reports regarding equipment maintenance. 3) obstacles from short cargo which is done by checking dry bulk loading and unloading calculations. 4) obstacles from bad weather which is carried out by monitoring weather conditions through ship navigation equipment.

Harvesting energy from a soldier's gait using the piezoelectric effect

Abstract There is an increasing dependence on electronic devices in the battlefield, including equipment for communications, positioning and navigation, and combat situation awareness. These devices are usually powered by batteries because they are reliable and have good power density (energy per kilogram). Nevertheless, batteries are heavy and bulky, which reduces agility and increases fatigue of the ground troops. An alternative is to extract energy from renewable sources (like the sun and the wind) or harvest energy from the human body itself (like temperature gradients and walking). This article studies the feasibility of a piezoelectric generator, stimulated by human gait, to power electronic devices on the battlefield. Tests were carried out to measure the energy harvested from several piezoelectric ceramics placed under the sole of a soldier’s boot. Different materials and arrangements were tried to maximize the power, leading to the development of a prototype. The prototype was able to harvest 875 μ J {\rm{\mu }}{\rm{J}} on each step, on average. Walking 1 h, at a pace of 40 steps/min, leads to 2.1 J of energy, enough to supply a 3.3 V device consuming 10 mA for around a minute. These results are interesting for any situation that requires emergency power on the battlefield (e.g., trigger a device, call for rescue, acquire localization).

ТРЕБОВАНИЯ К ТОЧНОСТИ ПОЗИЦИОНИРОВАНИЯ АППАРАТУРЫ СПУТНИКОВОЙ НАВИГАЦИИ ПРИ ВНЕЗАПНОМ ОБНАРУЖЕНИИ ПРЕПЯТСТВИЙ НА ПУТИ СЛЕДОВАНИЯ БЕЗЭКИПАЖНЫХ СУДОВ

The paper considers a scientifically based approach to the formation of requirements for the accuracy of determining the location of unmanned vessels in order to prevent their collision with sudden obstacles. On the basis of probability theory, a criterion of navigational hazard of navigation is proposed, and quantitative estimates of the requirements for the accuracy of positioning of on-board satellite navigation equipment are obtained. The results of the work can be used in the organization of safe navigation and substantiation of requirements for navigation support of unmanned vessels.

Modeling and analysis of probabilistic characteristics of the functioning of low-channel equipment of consumers of global navigation satellite systems in conditions of signal-like interference

Formulation of the problem. A promising area of research in the field of functioning of navigation equipment for consumers of global navigation satellite signals is the development of protection of consumer equipment from the effects of simulated interference. The high availability of navigation signals of the open segment entails the threat of covert influence on consumer equipment. To date, protection measures against covert interference have been developed and applied for multi-channel consumer equipment with high computing capabilities. However, for low-channel consumer equipment, the development of such protection measures is required, for which it is necessary to determine the probabilistic characteristics of the functioning of the equipment under study under the influence of signal-like interference. Purpose. Determination of the probabilistic characteristics of the operation of multichannel navigation equipment for consumers of global navigation satellite signals in a complex interference environment. Results. A model of the functioning of consumer navigation equipment is constructed and mathematically described, the probabilistic characteristics of the functioning of consumer equipment in a complex interference environment are calculated, and the coefficient of effectiveness of signal-like interference is introduced. Practical significance. The results can be used by specialists in the field of satellite radio navigation in the development of protection systems against covert intentional exposure.

Noise-resistant multi-frequency phase local radionavigation system based radio interference transmitters

Formulation of the problem. The widespread use of electronic warfare has led to significant difficulties in the use of consumer navigation equipment (CNE) of global navigation satellite systems (GNSS). Local radio navigation systems, alternatives to GNSS, are characterized by low accuracy and low noise immunity. At the same time, a spatially distributed system of radio interference transmitters CNE GNSS, using wide-band multi-frequency BPSK signals, can be used to organize a noise-resistant LRNS, in which phase measurements will be used to increase the accuracy of measurements. Purpose. The purpose of this work is to justify the requirements for a local radio navigation system based on spatially distributed radio interference transmitters NAP GNSS, using the noise-resistant method of multi-frequency phase radio navigation. Results. An interference-resistant method of multi-frequency phase radio navigation is presented, and the requirements for a local radio navigation system based on this method are substantiated. For the given typical characteristics of NAP GNSS radio interference transmitters, the value of the frequency detuning of the spectral components of the multi-frequency signal was obtained, at which the best positioning accuracy is achieved. Practical significance. The results obtained can be used to organize a noise-resistant multi-frequency phase local radio navigation system based on NAP GNSS radio interference transmitters.

Model for generating data from navigation sensors for assessing the spatial position of objects

When selecting or developing new algorithms for assessing the spatial position of objects based on data from consumer navigation equipment (CNA) of global navigation satellite systems (GNSS) and data from inertial MEMS modules, the task of generating test model input data that meets certain conditions arises. Such conditions include, for example, the requirements for limited time increments of elements of spatio-temporal trajectories and ease of formation of their characteristic sections. The characteristic sections of spatio-temporal trajectories can be sections of a stationary position – sections of “Rest” or sections of rectilinear movement. The importance of forming these areas is due to the need to test the potential capabilities of compared or developed algorithms for assessing the spatial position of objects to ensure an improvement in their accuracy characteristics in the presence of such areas in various conditions. A data generation model is proposed for comparing algorithms for estimating the spatial position of objects, which ensures that the time increments of elements of spatio-temporal trajectories are limited in time and the simple formation of their characteristic sections is met. The model is based on the selection of a set of specified parameters that would allow, on the one hand, to form characteristic sections of spatio-temporal trajectories, and, on the other hand, to obtain model output data of NAP GNSS and inertial MEMS modules. The selected set of specified model parameters is determined through a set of analytically specified functions with sequential calculation of their parameters, which is much simpler compared to traditional approaches that involve solving boundary value problems of optimal control with restrictions on the type of control functions or the construction and application of genetic models and algorithms. The use of the developed model makes it possible to generate test model input data for the selection or development of new algorithms for assessing the spatial position of objects, implemented in devices that include CNA of GNSS and inertial MEMS modules and produce results both in real time and in delayed time. The effectiveness of the proposed solution is confirmed by the criterion of suitability under the considered conditions.

Compensation of high-power interference using eigen vectors of the correlation matrix

Formulation of the problem. The main means of protecting the navigation equipment of consumers of the global navigation satellite system from intentional interference is the spatial selection of information signals using an adaptive antenna array. In this case, the weight coefficients of the antenna array must be calculated without using information about the directions to the signal and interference sources. To calculate the weighting coefficients, the eigenvectors of the correlation matrix of the input signals of the antenna array, obtained during its spectral decomposition, can be used. Purpose. The purpose of this work is to present an algorithm for spatial interference compensation based on the spectral decomposition of the correlation matrix of the input signals of an adaptive antenna array and to evaluate its effectiveness. Results. An algorithm for spatial compensation of interference in a four-element adaptive antenna array is presented, based on the spectral decomposition of the correlation matrix of its input signals. The effectiveness of the presented algorithm was assessed using computer simulation. It was found that when the input of the antenna array was exposed to three interferences with an amplitude 500-2000 times greater than the amplitude of the information signal, the level of interference at the output of the antenna array decreased by more than 4000 times. Practical significance. The results obtained can be used in the development of a compensator for interference signals of navigation equipment of consumers of the global navigation satellite system.

Verification of the AIS service availability model based on dynamic data streams recorded from three receiving stations in the Polish coastal area

The reliability aspects of the operation of radio navigation systems constitute a crucial element for the safety of maritime navigation.. Technological progress in ship traffic monitoring is achieved through the design of ship systems and shore infrastructure equipped with Automatic Identification System (AIS) devices. One of the issues with AIS operation is the limited availability of the service in the form of data streams with an extended data age recorded on the receiving side. Another problem is the emission and reception by ships of incomplete positional reports without navigational parameters. Such situations render the system operationally unfit in terms of processed information. Therefore, it is essential to investigate the operational characteristics of radio navigation systems and develop tools to monitor the AIS service status on the receiving side. This article presents the development of a model for the availability of an AIS for vessels based on the determined mean time of the occurrence of incomplete navigation parameter values in AIS messages and the results of research in the domain of time and frequency using a mathematical method of the Fast Fourier Transform (FFT). The study results refer to six basic navigation parameters and show a varying service availability factor for the navigation parameters under study, i.e. the latitude (LAT), longitude (LON), speed over ground (SOG), course over ground (COG), heading (HDT), and the rate of turn (ROT). The data recorded by three receiving AIS stations on the Polish coast, i.e. PLKOL, PLSZZ, and PLSWI, were used as a key source of practical knowledge on the limitations of the AIS service availability. The experiment observed interruptions in the regular transmission of data from navigation equipment in the AIS service operational zone. As a result, the functional relationship was described based on the spectral analysis of the frequency of occurrence of times between the service repair (Time To Repair, TTR), and the model was proposed to be applied to the study of other variables. The presented model is a tool that allows for improving the monitoring of vessel traffic in terms of reliability, which directly affects the improvement of maritime traffic safety.

THE RELIABILITY EVALUATION OF THE DECK MACHINERY AND GALLEY EQUIPMENT OF A BULK CARRIER BY UTILIZING THE FAILURE RECORDS

Among various modes of transportation, maritime transportation holds critical importance since it provides substantial carrying capacity with low unit costs. To perform seamless and efficient operations in maritime transportation plays a pivotal role in achieving sustainable development goals and the International Maritime Organization (IMO) targets. The execution of uninterrupted operations can only be carried out with the existence of reliable systems. Creating reliable systems onboard is possible through the implementation of planned and proactive maintenance strategies and leveraging experiences gained from past failures. 10-year failure records of bulk carriers have been scrutinized within the scope of system reliability to determine critical equipment and units. The data has been categorized into subgroups under four fundamental headings, and subsequent reliability analyses have been conducted on each subgroup. Within the subgroups, the reliability of navigation equipment should be improved since it has the highest failure rate and its malfunction can cause very serious marine accidents. This equipment is followed by fire-fighting systems, cargo equipment, and GMDSS instruments which are essential for ship operations based on reliability results. Therefore, regular failure records, planned and proactive maintenance strategies, and also extra efforts should be performed on this equipment to ensure sustainable and seamless operations in the maritime sector.

Resilient Factor Graph-Based GNSS/IMU/Vision/Odo Integrated Navigation Scheme Enhanced by Noise Approximate Gaussian Estimation in Challenging Environments

The signal blockage and multipath effects of the Global Navigation Satellite System (GNSS) caused by urban canyon scenarios have brought great technical challenges to the positioning and navigation of autonomous vehicles. In this paper, an improved factor graph optimization algorithm enhanced by a resilient noise model is proposed. The measurement noise is resilient and adjusted based on an approximate Gaussian distribution-based estimation. In estimating and adjusting the noise parameters of the measurement model, the error covariance matrix of the multi-sensor fusion positioning system is dynamically optimized to improve the system accuracy. Firstly, according to the approximate Gaussian statistical property of the GNSS/odometer velocity residual sequence, the measured data are divided into an approximate Gaussian fitting region and an approximate Gaussian convergence region. Secondly, the interval is divided according to the measured data, and the corresponding variational Bayesian network and Gaussian mixture model are used to estimate the innovation online. Further, the noise covariance matrix of the adaptive factor graph-based model is dynamically optimized using the estimated noise parameters. Finally, based on low-cost inertial navigation equipment, GNSS, odometer, and vision, the algorithm is implemented and verified using a simulation platform and real-vehicle road test. The experimental results show that in a complex urban road environment, compared with the traditional factor graph fusion localization algorithm, the maximum improvement in accuracy of the proposed algorithm can reach 65.63%, 39.52%, and 42.95% for heading, position, and velocity, respectively.

The Role of Emergency Generator during Black-Out on the MV. Kelud

Emergency generator is an auxiliary machine that functions to generate electrical power to meet the electrical needs of the ship during an emergency (black-out). This research was conducted to find out what caused the black-out onboard KM. Kelud, how the role of the Emergency generator during a black-out, and how to maintain the emergency generator so that it is always ready when used. The research method that the author uses is a qualitative research method. Data collection is done through interviews and observations. The results obtained from this study indicate that the cause of the black-out on KM. Kelud is the entry of mud into the hull, causing the cooling system in the main engine to be disrupted and eventually black-out. The role of the emergency generator during a black-out is as a temporary source of electricity to run several devices, such as navigation equipment, ship lighting, fire alarm systems, sprinkle pumps, and watertight door systems. In order for the emergency generator to run according to its function, it must be carried out routine maintenance such as checking batteries, oil and lubricants, cooling systems, and periodic testing.

Optimizing the Use of Radar when the Ship is Moving in MT. Green Plus

It is believed that the high number of collisions in narrow shipping lanes is caused by the lack of skill of sailors. Therefore, this analysis aims to determine the role of Radar in preventing collisions at sea. The research approach is qualitative, and the data will be presented using descriptive analysis. The research findings indicate that the decrease in Radar function is due to the non-implementation of Standard Operating Procedures (SOPs), the officers' lack of understanding of the manual books, and damage to the scanner. The consequences of a decrease in Radar function include navigation hazards because the Radar does not function correctly, making it difficult for the watch crew to identify other ships. To optimize the use of Radar when ships are moving at night, it is necessary to regularly check, maintain and repair navigation equipment.

Climate change: A pointer to increased small-scale fisher drowning deaths.

Drowning is an overlooked public health concern and drowning risk is dependent on environmental risk factors. The preponderance of drowning deaths occurs in low- and middle-income countries. Small-scale fishers face high occupational risk of drowning. Climate change increases the frequency and intensity of storms, thereby exacerbating fishers' risks and creating a need to examine the contribution of storms to fisher drowning deaths for the development of mitigation strategies. We examined this relationship between weather and fisher drowning deaths in Lake Victoria, which is Africa's largest lake, a site of high fishing pressure, and where climate change is predicted to increase thunderstorms. We conducted a verbal autopsy with people knowledgeable about recent fatal fisher drowning incidents to collect information about the deceased fishers and circumstances surrounding the incidents across 43 landing sites in the Kenyan shore of Lake Victoria. Semi-structured interviews with stakeholders also elucidated community perspectives on drowning risks. Fatal drownings were often attributed to bad weather (41.8%). Other risk factors, such as non-use of life jacket and navigation equipment, co-occurred with bad weather at high rates (69.5% and 67.8%, respectively) to jointly contribute to fatal drowning incidents. Such co-occurrence of risk factors indicates that actions across multiple risk factors can help mitigate the issue. Stakeholder analysis revealed a range of opportunities for improved communication of risks and action to mitigate risks across boat operators and manufacturers, as well as multiple levels of management. Across global small-scale fisheries, limited use of safety equipment and intensive fishing pressure may coincide with increases in extreme weather events, necessitating action to address current and mitigate future drowning risks to small-scale fishers.

Theoretical substantiation of system for organising preventive treatment of asphalt concrete road pavements

Introduction. Over the past 20 years, the fleet of vehicles in the Republic of Belarus has increased significantly, and, consequently, the intensity of traffic on roads with a proportional increase in wear and tear of their surfaces. The need to protect asphalt concrete pavements from premature destruction dictates the search for new technological solutions. To effectively protect asphalt concrete pavements from the complex effects of water and traffic loads in the autumn-winter and spring-winter periods, the author has developed and implemented one of the options for protecting asphalt concrete pavements of a highway – treating them with a hydrophobic preventive Protekt- 01composition.Materials and methods. The research used theoretical and practical results from the implementation of the developed hydrophobic prophylactic composition.Results. The article presents an overview of the state of the problem of preventing destruction of asphalt concrete pavements abroad and in the Republic of Belarus, an analysis of the measures taken to implement the developed hydrophobic preventive Protekt-01composition at transport infrastructure facilities, and also, based on the data obtained from production testing a ‘System for organizing preventive treatment’ has been proposed, which will be aimed at preventing the beginning and future destruction of the asphalt concrete pavement of highways and will be based on monitoring the technical condition of the control object, planning, organizing, implementing and managing preventive and repair measures using navigation equipment and software that makes it possible to optimize the balance of costs and road surface defects.Originality. Thus, based on the theoretical substantiation and the results of practical implementation of the developed composition, the following are proposed:- method for ensuring the operation of a control system for liquid road-building materials which enables to eliminate overconsumption of the distributed substance;- ‘System for organizing preventive treatment’, which enables to increase the service life of asphalt concrete pavement by 1.2–1.5 times.

Patent Technology of Shipborne Stabilized Platform

Background: When a ship is sailing or operating at sea, it is unavoidable to produce sixdegrees- of-freedom movements of rolling, pitching, and yawing under the action of sea wind and waves, which seriously impacts the operation of precision equipment on the ship and the safety of personnel. The ship-borne stabilized platform can isolate the ship's motion and eliminate the impact of sea waves on the personnel and equipment on it to a large extent. With the increasing demand for ship surfaces in marine fields, such as navigation equipment, military facilities, and sea condition simulation, there is an urgent need to study ship-borne platforms with high stability and efficiency to isolate swaying and ensure ship performance. Objective: This study aims to analyse the patents and summarize the characteristics and existing problems of the shipborne platform to provide a reference for the future development of the shipborne stabilized platform. Methods: Various representative patents related to shipborne stabilized platforms and multi-DOF platforms were researched in this study. Results: Through the analysis and comparison of patent technology, the main problems existing in the structure and design principle of the existing shipborne stabilized platform are summarized, and the development trend and direction of the shipborne stabilized platform are discussed. Conclusion: Shipborne stabilization is highly significant in isolating the ship's motion. At present, the ship-borne stabilized platform has produced six degrees of freedom of movement, but due to the improvement of control response requirements, the structure of the platform needs to be further improved. With the development of test technology toward intelligent and big data-driven technology, the shipborne stabilized platform is moving toward cloud computing and large-scale testing.