Ship Control System Research Articles

Postharvest Management Practices of Maize in Ethiopia: A Review

Postharvest losses and their management practices of Maize production in Ethiopia were overviewed. Agriculture is vital for addressing food security problems in Ethiopia. Agriculture contributes to overcoming the food security problem through growth that distributes its benefits as widely as possible by increasing production and productivity. About 30 to 50 per cent postharvest loss is because of inappropriate collection, transport, storage and pest control systems in Ethiopia were found tremendous for different cereal grains. The review was done by collecting the various published and unpublished materials relevant information from different literature sources like libraries, research report, journals, books and Internet center. Postharvest quantity and quality loss of cereal grains in developing countries appear to be initiated mostly at the farm level, so the potential solutions for the problem are needed at the same level. To minimize losses and increase the shelf life of the food grains which inhibit the growth of pests and provide proper storage facilities, appropriate packaging materials and transportation facilities are required. A corrective suggestion on suitable approaches to loss reduction in postharvest handling of maize grains was reviewed. As the result of review, it concludes that further studies are needed concerning physical, bio-chemical and socio-economic aspects at each production level.

Self-Oscillating Liquid Gating Membranes with Periodic Gas Transport.

Liquid gating membranes with molecular-level smooth liquid lining layers break through the limitations of traditional porous membrane materials in gas transport control. Owing to the stable, self-healing, and reconfigurable properties, liquid gating membranes have shown wide application prospects in microfluidics, intelligent valves, chemical reactions, and beyond. Here, we develop a periodic gas transport control system based on the self-oscillating liquid gating membrane. Under continuous gas injection, the gas–liquid interface is reversibly deformed, enabling self-oscillating behavior for discontinuous and periodic gas transport without the need for any complex external changes to the original system. Meanwhile, our experimental analysis reveals that the periodic time and periodic gas release in the system can be regulated. Based on the cycle stability of the system, we further demonstrate the controllability of the system for periodic droplet manipulation in microfluidics. Looking forward, it will offer new opportunities for various applications, such as pneumatic robots, gas-involved chemical reactions, droplet microfluidics, and beyond.

Filament Transport Control for Enhancing Mechanical Properties of Parts Realised by Fused Filament Fabrication.

The fused filament fabrication (FFF) process is widely used for producing prototypes and functional parts for diverse applications. While FFF is particularly attractive due to its cost-effectiveness, on the other hand, the fabricated parts have limitations in terms of large manufacturing time and reduced mechanical properties. The latter is strongly influenced by the fabrication process parameters, which affect the interlayer bonding and the adhesion between consecutive layers. Several works presented in the literature analysed the correlation between mechanical properties and process parameters. It was demonstrated that an increase in the fabrication feed rate causes slippage between filament and the feeding system, which leads to a decrease in the extruded material flow, and thus in part density. This work aims to investigate how the limitation of the slippage phenomenon affects the mechanical properties of parts fabricated using the FFF process. A prototype machine, equipped with a closed-loop control system on filament transport, was used to fabricate samples for tensile tests and dynamical mechanical analysis. Samples fabricated enabling the filament transport control showed an increase both in ultimate tensile strength and elongation at break for those fabricated with disabled control, whilst a decrease in stiffness was observed. In addition, the results showed that the use of a filament transport control system on a FFF machine increases the possibility of fabricating high value-added parts.

AUTONOMOUS SHIP CONTROL IN SHALLOW AND CONFINED WATER

The paper describes the definition and usage of autonomous ship control systems in shallow and confined water. The application of such control system is shown in a case study : a systematic analysis of ship transits in the approach channel to the Port of Antwerp (Western Scheldt) .The control algorithm not only is capable of correctly navigating the ship through the fairway, it also delivers insight in rudder and propeller usage in function of the tidal conditions. Such control systems are validated based on model tests carried out in towing tanks. Flanders Hydraulics Research (FHR) has recently inaugurated their second towing tank, the Towing Tank for Manoeuvres in Shallow Water. One of the functionalities of this facility is the role it can play as test basin for autonomous shipping. Next to the further validation and expansion of existing control scenarios, it will be used to model interaction events between multiple ships. A numerical effort to model interaction events is presented, which will be validated in the model test basin.

Supervisory risk control of autonomous surface ships

The objective of this paper is to develop online risk models that can be updated as conditions change, using risk as one metric to control an autonomous ship in operation. This paper extends and integrates the System Theoretic Process Analysis (STPA) and Bayesian Belief Networks (BBN) with control systems for autonomous ships to enable supervisory risk control. The risk metric is used in a Supervisory Risk Controller (SRC) that considers both risk and operational costs when making decisions. This enables the control system to make better and more informed decisions than existing ship control systems. The novel control system is tested in a case study where the SRC can change: (i) which machinery system is active; (ii) which control mode to run the ship in; and (iii) which speed reference to follow. The SRC is able to choose the optimum machinery, control mode, and speed reference to maintain safe control of the ship over a route in changing conditions.

ЦИФРОВИЗАЦИЯ УПРАВЛЕНИЯ И КОНТРОЛЯ ТРАНСПОРТНО-ЛОГИСТИЧЕСКИМ ОБЕСПЕЧЕНИЕМ РЕСУРСОДОБЫВАЮЩЕГО КОМПЛЕКСА

The article describes the management and control system for transport and logistics support of the resource-extracting complex. The stages of management and control processes are presented. A conceptual model for transport and logistics support management has been developed using the graph theory, which represents itself a basis for artificial intelligence systems.

Mathematical Problem of the Stability Theory of the Gas Diesel Transport Control System

The existing unique solution of a system of equations describing motion along a given trajectory in the space of variables is considered when the vector function meets the conditions of the Cauchy problem. The stability of those functions that are positive everywhere except for the equilibrium position is estimated. The stability of linear autonomous systems is determined by the roots of the characteristic equation of the matrix.

Internet of Things for Smart Transportation in North Moluccas Province

The Internet of things is a service that supports the realization of the smart city concept. Connectivity between computer devices and computers and computers with sensors connected to the Internet supports community activities that improve the quality of life. Smart transportation is part of the smart city concept that focuses on an efficient transportation control system. The mobility of the people of the northern Maluku province is very dependent on land and marine transportation modes due to the geographical condition of the province, which is in the form of an archipelago. The safety and efficiency of marine transportation is still a topic that needs attention today. This paper proposes an IoT-based smart transportation model that focuses on marine transportation. Machine-to-machine (M2M) protocol, telecommunications technology, and cloud computing play an essential role in this research.

Potential-induced wetting and dewetting in pH-responsive block copolymer membranes for mass transport control.

Wetting and dewetting behavior in channel-confined hydrophobic volumes is used in biological membranes to effect selective ion/molecular transport. Artificial biomimetic hydrophobic nanopores have been devised utilizing wetting and dewetting, however, tunable mass transport control utilizing multiple transport modes is required for applications such as controllable release/transport, water separation/purification and energy conversion. Here, we investigate the potential-induced wetting and dewetting behavior in a pH-responsive membrane composed of a polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) block copolymer (BCP) when fabricated as a hierarchically-organized sandwich structure on a nanopore electrode array (NEA), i.e. BCP@NEA. At pH < pKa(P4VP) (pKa ∼ 4.8), the BCP acts as an anion-exchange membrane due to the hydrophilic, protonated P4VP cylindrical nanodomains, but at pH > pKa(P4VP), the P4VP domains exhibit charge-neutral, hydrophobic and collapsed structures, blocking mass transport via the hydrophobic membrane. However, when originally prepared in a dewetted condition, mass transport in the BCP membrane may be switched on if sufficiently negative potentials are applied to the BCP@NEA architecture. When the hydrophobic BCP membrane is introduced on top of 2-electrode-embedded nanopore arrays, electrolyte solution in the nanopores is introduced, then isolated, by exploiting the potential-induced wetting and dewetting transitions in the BCP membrane. The potential-induced wetting/dewetting transition and the effect on cyclic voltammetry in the BCP@NEA structures is characterized as a function of the potential, pH and ionic strength. In addition, chronoamperometry and redox cycling experiments are used to further characterize the potential response. The multi-modal mass transport system proposed in this work will be useful for ultrasensitive sensing and single-molecule studies, which require long-time monitoring to explore reaction dynamics as well as molecular heterogeneity in nanoconfined volumes.

AN EFFICIENT GRAPH THEORY-BASED ALGORITHM FOR SHIP TRAJECTORY PLANNING

The research presented in this paper is dedicated to the development of a path planning algorithm for a moving object in a dynamic environment. The marine environment constitutes the application area. A graph theory-based path planning method for ships is introduced and supported by the results of simulation tests and comparative analysis with a heuristic Ant Colony Optimization approach. The method defines the environment with the use of a visibility graph and uses the A* algorithm to find the shortest, collision-free path. The main contribution is the development of an effective graph theory-based algorithm for path planning in an environment with static and dynamic obstacles. The computational time does not exceed a few seconds. Obtained results allow to state that the method is suitable for use in an intelligent motion control system for ships.

Application and Transformation of Centralized Control System for Mine Belt Transportation

Application and Transformation of Centralized Control System for Mine Belt Transportation

IMPROVEMENT OF ROBOTIC SYSTEMS BASED ON VISUAL CONTROL

The subject of research in the article is the use of adaptive visual control in flexible integrated robotic systems. The goal of the work is the integration of visual control facilities into automated control systems for transport and handling operations of flexible integrated production. The article solves the following tasks: analyze the application of visual control methods in robotics, consider methods for improving adaptive visual work control systems, formulate the basic requirements for adaptive visual control systems, and develop a control model for a mobile robot in the space of a flexible integrated production systems and computer vision systems. To solve the set tasks, the methods of set theory, methods of automatic control theory, and methods of the theory of image processing were used. The following results were obtained: the analysis of visual control systems was carried out from the point of view of solving the problems of flexible integrated systems of modern production; the adaptive visual control scheme was improved by introducing a declarative workspace model and a functional model of a flexible integrated system; the main requirements and tasks of adaptive visual control systems are formulated; considered the main stages of processing visual information and their practical implementation, including multi-zone workspaces; a model of visual control of a mobile robot in a flexible integrated production workspace has been developed; the practical tasks of managing mobile platforms have been solved. Conclusions: the use of adaptive visual control in a production environment will allow combining the elements of flexible integrated production distributed in space, providing monitoring, control and refinement of control processes in real time, the functioning of intelligent control tools, which will improve the quality of control processes.

Design of the Power System and Remote Control System for the Unmanned Ship

In lakes and reservoirs with high environmental protection requirements, it is necessary to adopt pure electric intelligent water quality monitoring ships, adopt pure electric power systems and intelligent remote control systems. This article specifically completed the design of the power system and remote control system of the smart ship, and elaborated the design method in detail. The system has the characteristics of high reliability, miniaturization, and modularization. The successful development of the system has greatly improved the intelligence of water quality monitoring ships, and has a positive effect on small intelligent ships in lakes and reservoirs.

Control of Dynamic Positioning System with Disturbance Observer for Autonomous Marine Surface Vessels.

The main goal of the research is to design an efficient controller for a dynamic positioning system for autonomous surface ships using the backstepping technique for the case of full-state feedback in the presence of unknown external disturbances. The obtained control commands are distributed to each actuator of the overactuated vessel via unconstrained control allocation. The numerical hydrodynamic model of CyberShip I and the model of environmental disturbances are applied to simulate the operation of the ship control system using the time domain analysis. Simulation studies are presented to illustrate the effectiveness of the proposed controller and its robustness to external disturbances.

Analyzing vibration parameters of a modern high-speed engine during operation

The paper presents results of experimental research into vibration parameters of a modern electronic control-enabled main high-speed engine, Caterpillar CAT 3516B as obtained during a running trial of a sea tug. CAT 3500 series Caterpillar high-speed engines are extensively used in sea tugs; there are about 40 units installed in vessels operating in the Azov and Black Sea region. The research technique involved measurement of vibration displacement, vibration velocity, vibration acceleration at an engine and its turbocharger components. The conducted experimental research has shown that in order to evaluate the technical state of an engine, it is necessary to measure vibration displacement and vibration velocity in a frequency range from 1 to 1000 Hz at 0.1 Hz intervals. For turbochargers, the vibration acceleration shall be measured in a frequency range from 1 to 15000 Hz at 1 Hz intervals. The results of the experimental research allowed determining necessary conditions for measurement of vibration parameters of Caterpillar CAT-3500 series modern high-speed engines commonly used in sea tugs. The experimental research into vessel installations by in-place diagnostics at operating sea-going vessels forms a foundation of an autonomous ship control system.

Multicriteria assessment of optimal forecasting models in decision support systems to ensure the navigation safety

When developing the Decision Support System (DSS), the operability of the internal motion and maneuvering control systems of the vessel is characterized by a large number of parameters, which should be monitored in order to achieve the expected results. The task is to develop an appropriate methodology for automatic monitoring of these systems, which, using a minimum set of sensors, makes it possible to predict the state of the vessel and change the dangerous state to the safe one. To implement the method of automatic monitoring, a set of statistical control tools is selected depending on the alleged violations and the level of correlation of parameters. The uncorrelated parameters are monitored by instruments based on the Shewhart map [1], the correlated parameters are monitored on the basis of Hotelling statistics [2]. This approach makes it possible to diagnose the pre-emergency and emergency states of ship control systems in on-line mode. The method used for multi-level integrated monitoring of the technical state of control systems in on-line mode can improve the reliability of of identification of the technical state of vessel subsystems and expandthe scope of application of monitoring and diagnostics tools. The data obtained can become the basis for the development of rational decisions in the DSS at the level of control subsystems for the vessel transfer from the dangerous to safe state.

Структура и применение автоматизированной системы мониторинга пассажиропотока

Various methods of collecting data on passenger traffic, their advantages and disadvantages are considered. It is shown that in order to improve the quality of transport services, it is necessary to regularly collect and refine data on passenger traffic. The goals and methods of obtaining information about passenger traffic in the system of municipal passenger transport are indicated. All currently existing methods are divided into three categories: data collection using technical means, data collection with the help of censors and volunteers, and interpretation of fare payments. All the methods presented in the article were compared in terms of labor intensity, costs and accuracy of the results obtained. The advantages and disadvantages of each method are considered. The general structure of an automated system for collecting data on passenger traffic is presented. The necessity of creating a centralized system for collecting and processing data associated with all passenger transport control systems has been substantiated. The tasks solved by this system at all levels of transport services for passengers are shown. Each of the tasks is assigned to one of three service levels: pre-transport, transport and post-transport. It is shown that only solving problems at all levels can ensure high-quality operation of the municipal passenger transport system.

Amphibious Transport of Fluids and Solids by Soft Magnetic Carpets.

One of the major challenges in modern robotics is controlling micromanipulation by active and adaptive materials. In the respiratory system, such actuation enables pathogen clearance by means of motile cilia. While various types of artificial cilia have been engineered recently, they often involve complex manufacturing protocols and focus on transporting liquids only. Here, soft magnetic carpets are created via an easy self‐assembly route based on the Rosensweig instability. These carpets can transport not only liquids but also solid objects that are larger and heavier than the artificial cilia, using a crowd‐surfing effect.This amphibious transportation is locally and reconfigurably tunable by simple micromagnets or advanced programmable magnetic fields with a high degree of spatial resolution. Two surprising cargo reversal effects are identified and modeled due to collective ciliary motion and nontrivial elastohydrodynamics. While the active carpets are generally applicable to integrated control systems for transport, mixing, and sorting, these effects can also be exploited for microfluidic viscosimetry and elastometry.

Deep learning and mobile control system for hazardous materials transportation

Artificial intelligence is a powerful tool to learn and predict traffic effects according to drivers' behavior and make effective predictions to support traffic management team. This paper presents a proposal using reinforcement deep learning, simulation, and performance analysis of road systems with improvement in hazardous materials transportation control. The analysis reports the reduction of accident detection time and damages caused by traffic jams. The use of smartphone sensors, artificial intelligence, and an integrated control system for tracking, management, monitoring, and control of hazardous materials transportation allows for the reduction in detection time.

Observer-Based Autopilot Heading Finite-Time Control Design for Intelligent Ship with Prescribed Performance

Traffic engineering control is a major challenge in marine transportation. Cost efficiency and high performance demand advanced technologies for the ship control systems. This paper develops an autopilot heading control scheme based on a fuzzy state observer for an intelligent ship on this subject to track the prescribed function while calling for performance limitation and order execution time. A fuzzy logic system (FLS) is adopted to approximate the unknown uncertainties caused by the changes in water depth, wind, wave, ship loading, and speed in navigation. State observer is required to obtain unknown yaw rate. By adopting performance function and tracking error transformation techniques, the heading tracking error can converge to prescribed performance bounds. Taking settling time into account, the finite-time adaptive prescribed performance control algorithm can save more resources effectively. Based on the Lyapunov stability theory, the observer-based adaptive fuzzy control approach does not cause any unbounded signal, the system remains stable. Meanwhile, the autopilot heading control system with an unknown yaw rate and constraint state can benefit from the given design.