Operation Of Autonomous Systems Research Articles

SUBSTANTIATION OF USE OF BUTANE FOR GASIFICATION OF OBJECTS

Statement of the problem. The variable composition of liquefied petroleum gas has a significant impact on the operation of autonomous gas supply systems. The presence of the butane fraction under conditions of sub-zero temperatures leads to the cessation of the generation of the vapor phase in the tank, moisture condensation and the formation of ice and hydrate plugs.Results. The features of the use of technical butane in gas supply systems are considered. The composition of the gas-air mixture is recommended, taking into account the restrictions on deviations in the Wobbe number, ensuring the completeness of combustion of the mixture in gas-using installations of the consumer. The level of filling underground tanks with technical butane is justified, taking into account the coefficient of volume expansion of gas in the presence of extreme operating temperatures.Conclusions. The composition of butane-based gas-air mixtures for gas supply to consumers was determined that meets the condition for the interchangeability of combustible gases and provides lower dew point temperatures; the level of filling of ground and underground tanks with technical butane is justified.

Completion of multi-vehicle driverless test verification of Casco’s train operation system based on vehicle-to-vehicle communication

Late at night on June 28, 2020, Casco Signal Co., Ltd. (Casco) Train Autonomous Operation System (TACS) based on vehicle-to-vehicle communication successfully completed the unmanned driving test verification on Shanghai Rail Transit Line 3/4. Finally, all the verification indexes of the Casco vehicle-to-vehicle communication TACS system achieved the expected goals, and the system was highly praised by the review experts.

Askeri Otonom Sistemlerde Blokzincir Tabanlı Veri Güvenliği

Advances in technology have enabled the increased use of autonomous systems such as unmanned aerial vehicles (UAVs) in military operations and other critical military communications. While the use of autonomous systems has greatly facilitated military operations, provided a global view of the operational environment and eased sensitive data collection, making possible reduced casualties, it has also created a greater cyber attack surface due to its high level of automation. The existence of adversaries targeting this attack surface can seriously damage military operations by tampering with critical message content used in autonomous systems decision making. In order to ensure the successful operation of autonomous military systems, mechanisms must be developed to strictly protect the integrity of the collected / exchanged data and messages, and an immutable record of each message must be provided. These mechanisms should also be used to control autonomous systems under critical failures or attacks occurring during or after military operations. Blockchain has recently emerged as a technology that provides a decentralized architecture to achieve an unchangeable history of interactions between parties that are part of a distributed network. While blockchain is currently used in various fields such as cryptocurrencies, supply chain management and e-voting systems, it also has the potential to provide secure communication in autonomous systems. In this study, a blockchain-based communication architecture is proposed that guarantees integrity assurance and permanent recording of messages exchanged between all parties, including UAVs and ground control stations, in a military autonomous system network. The proposed secure communication architecture has been theoretically evaluated in terms of its resistance to the types of cyber attacks frequently encountered in distributed systems, and it has been shown to provide protection against attacks that compromise data integrity as well as spoofed authentication attempts. The proposed blockchain-based architecture is promising to increase the resilience of military autonomous systems against cyberattacks that aim to hurt the success of military operations through data content manipulation.

Design and implementation of graphical interface of vehicle display and control system based on SylixOS

To satisfy the design requirements of the current vehicle display and control system, and in consideration of the independent controllable requirements of the current software and hardware platforms, this paper proposed a set of nationalized solution. The Loongson 2K1000 was selected as the main control chip, and the interface design and development of vehicle display control system was completed based on the SylixOS autonomous real-time operating system. This paper elaborated on the development process of the open source graphics library Qt, and proposed solutions to the screen flicker problem encountered during the development process.

Mobile Robot Simulation and Navigation in ROS and Gazebo

mobile robots are entering our daily lives as wellas in the industry. Their task is usually associated with carryingout transportation. This leads to the need to performautonomous movement of mobile robots. On the other hand,modern practice is that the planning of most processes is donethrough simulations. Thus, various future production problemscan be anticipated and remedied or improved. The articledescribes the creation of a mobile robot model in the Gazebosimulation environment. Specific settings and features forrunning a mobile robot in autonomous navigation mode underthe robot operating system are presented. The steps for creatinga map, localization and navigation are presented. Experimentshave been conducted to optimize and tune the parameters ofboth the robot model itself and the simulation controlparameters.

General principles of expanding the speed range of operation of autonomous power supply systems for passenger cars

Authors address the issues of expanding the speed range for operation of autonomous power supply systems for air-conditioned passenger cars. For the first time in the domestic car construction, the issue of reducing the minimum start-up speed of a generator-drive unit arose when the passenger fleet of the Sakhalin Railway was renewed, where the speed of passenger cars is much lower than the overall network speed. Research carried out by CJSC SO TIV and JSC TVZ has shown that the use of V-belts in the modernization of the textropic-reduction-cardan drive allows solving this problem. Kinematic diagram of the drive was adopted without changes, but with the replacement of the V-belts C (B)-2360T with new narrow belts XPC-2360 without working surface wrap and with a formed tooth on the lower base. In the tensioner, the main spring with a stiffness of 75 N/mm was replaced with a spring of increased stiffness (100 N/mm). The main change was the replacement of the 2GV003 generator with a 2GV008 low-speed generator, which has a minimum rotation at full power (700 rpm). This modernization of the drive made it possible to turn on the generator 2GV008 at rated power, starting at a speed of 30 km/h. The article sets the task of expanding the speed range of operation of the EV-7 and EV-10 autonomous power supply systems for cars without air conditioning. It is solved by forcing the excitation of the generators. Analysis of modern systems of autonomous power supply of passenger cars showed that the expansion of the speed range of its operation can be achieved in three ways: • raising the gear ratio of the gearbox to ensure it is switched on to the nominal mode at a carriage speed of 15 - 20 km/h without changing the parameters of the generator and the entire system of autonomous power supply; • modernization of the electrical equipment complex for passenger cars to ensure the operation of the main power consumers and charge the battery while driving at low speeds (over 18 km/h) without changing the mechanical parameters and composition of the serial generator-drive unit; • modernization of the generator in order to reduce its turnon revolutions to the power required to provide the main power consumers without changing the mechanical parameters of the drive. All three methods have its advantages and disadvantages, the choice of any of them is determined by the technical requirements for a specific car model.

A Probabilistic Approach to Analyze Wind Energy Curtailment in Non-Interconnected Greek Islands Based on Typical Wind Year Meteorological Data

Wind energy and photovoltaic solar energy (PV) are the most mature renewable energy technologies and are widely used to increase renewable energy penetration in non-interconnected Greek islands. However, their penetration is restricted due to technical issues related to the safe operation of autonomous power systems, the current conventional power infrastructure and their variable power output. In this framework, renewable energy curtailment is sometimes a necessity to ensure the balance between demand and supply. The ability of autonomous power systems to absorb wind and PV power is related to the load demand profile, the type and the flexibility of conventional power plants, the size of power system and the spatial dispersion of wind farms. In this connection, a probabilistic approach for estimating wind energy curtailment is thoroughly applied in most of the autonomous power systems in Greece, using detailed information about load demand and conventional power supply. In parallel, high resolution mesoscale model-based hourly wind data for typical meteorological wind year are used to represent the wind features in all the sites of interest. Technical constraints imposed by the local power system operator, related to the commitment of conventional power plants and the load dispatch strategies are taken into account to maximize renewable energy penetration levels. Finally, application for wide ranges of wind and PV capacity and the thorough analysis of the parameters leads to the presentation of comparable results and conclusions, which could be widely used to predict wind energy curtailment in non-interconnected power systems.

A Delphi-AHP study on STCW leadership competence in the age of autonomous maritime operations

Accelerating technological advancement in the maritime industry is gradually increasing the range of functions once performed by humans to become automated. In the era of autonomous shipping, where the autonomous operating system takes the lead and data flows define decision-making, how the ship and its leaders can successfully navigate these new ways of working have important implications for safety, efficiency and reliability of future ship operations. It is critical that the non-technical skills requirements, in particular the leadership competencies, be re-evaluated as new operational paradigms of shipping systems emerge and evolve. This study extends the current research of Maritime Autonomous Surface Ships (MASS) by using a Delphi consensus survey and Analytic Hierarchy Process (AHP) with a panel of 36 experts to (1) bridge a knowledge gap, i.e., the lack of an understanding regarding the leadership implication of autonomous shipping; (2) evaluate the applicability of current STCW leadership requirements for MASS operations; (3) identify and prioritize the leadership competences that should be accrued by the personnel involved in future ship operations. The results have shown that the current STCW framework is not fully relevant for MASS. The redefined leadership competence and the constructed hierarchy of criticality generated from this study can be valuable input for revision of the STCW and maritime education and training practices, contributing to successful ship operations of the future.

<b>Trends and Topics of Research and Development Related to the Sophistication of Signalling and Telecommunication Systems</b>

Following recent developments in information and communication technology (ICT), various research and development projects are ongoing around the world to propose new train control technology for safer and more stable transportation services. In particular, 5th generation mobile communication network systems (5G) which will be partially available in 2019 are expected to be used for critical roles in various safety related systems in the future, such as for automatic driving systems for road vehicles and train control systems. This paper outlines recent trends in basic studies for utilizing various communication network techniques including content centric network techniques and 5G systems to sophisticate signalling systems and train control systems. This paper also introduces a future plan for the challenges of the developing autonomous train operation and control system to realize safer, more stable and low-cost train operation services.

Efficiency Limits of Underwater Solar Cells

Summary Operation of underwater vehicles and autonomous systems is currently limited by the lack of long-lasting power sources. These systems could potentially be powered using underwater solar cells, but the material requirements to achieve their full potential are not well understood. Using detailed-balance calculations, we show that underwater solar cells can exhibit efficiencies from ∼ 55% in shallow waters to more than 65% in deep waters, while maintaining a power density >5 mW cm−2. We show that the optimum band gap of the solar cell shifts by ∼ 0.6 eV between shallow and deep waters and plateaus at ∼ 2.1 eV at intermediate depths, independent of geographical location. This wide range in optimum band-gap energies opens the potential for a library of wide-band-gap semiconductors to be used for high-efficiency underwater solar cells. Our results provide a roadmap for proper choice of underwater solar cell materials, given the conditions at points of use.

Interpretable Run-Time Monitoring and Replanning for Safe Autonomous Systems Operations

Autonomous robots, especially aerial vehicles, when subject to disturbances, uncertainties, and noises may experience variations from their desired states and deviations from the planned trajectory which may lead them into an unsafe state (e.g., a collision). It is thus necessary to monitor their states at run-time when operating in uncertain and cluttered environments and intervene to guarantee their and the surrounding's safety. While Reachability Analysis (RA) has been successfully used to provide safety guarantees, it doesn't provide explanations on why a system is predicted to be unsafe and what type of corrective actions to perform to change the decision. In this work we propose a novel approach for run-time monitoring that leverages a library of previously observed trajectories together with decision tree theory to predict if the system will be safe/unsafe and provide an explanation to understand the causes of the prediction. We design an interpretable monitor that checks at run-time if the vehicle may become unsafe and plan safe corrective actions if found unsafe. For each prediction, we provide a logical explanation - a decision rule - that includes information about the causes that lead to the predicted safety decision. The explanation also includes a set of counterfactual rules that shows what system variables may bring the system to the opposite safety decision, if changed. We leverage such an explanation to plan corrective actions that always keep the vehicle safe. Our technique is validated both with simulations and experiments on a quadrotor UAV in cluttered environments under the effect of previously untrained disturbances.

Hierarchical Attack Identification for Distributed Robust Nonlinear Control

Developing tools for attack identification in large-scale networked control systems is a research area of increasing significance for the secure and reliable operation of autonomous control systems. Due to scalability limits and privacy issues of individual subsystems, attack identification methods should not rely on global model knowledge. We address systems of interconnected nonlinear subsystems with coupled dynamics or constraints in a distributed control setup. The local controllers share information about the coupling variables of the subsystems and are designed to be robust towards attacks and uncertain influences through neighboring subsystems. We present a scalable hierarchical attack identification method which monitors the evolution of the coupling variables after an attack occurred in some unknown subsystem. Based on the mutual exchange of local sensitivity information among the subsystems, the propagation of the attack through the network is approximated. The propagation equations are used to formulate a quadratic program whose solution determines the attack signal that explains the observed network evolution best. The developed approach is applied to the IEEE 30 bus system to illustrate attack identification in power systems with faulty buses.

An efficient hybrid solar and electromagnetic harvesting system for autonomous operation of small sensors

In this study, we propose a combination of solar cells and a rectenna to realize a solar and electromagnetic energy harvesting system. The proposed harvester consists of a circular slot antenna, a rectifier circuit which is designed with a reverse-biased Schottky diode, and SHJ solar cells with a combination of AZO/TiO2 as antireflection coating and a diffraction grating morphology. Each designed component has been characterized through simulations and measurements. First, the solar cells are designed and investigated separately. Then, they are carefully placed near the slot loop antenna, which is attached to the rectifier circuit, to realize the combined harvesting system. The heterojunction solar cells with an intrinsic thin layer (SHJ) have been designed based on light trapping mechanism, which reduces the reflection of solar radiation and interfacial traps effects significantly. Solar cells’ simulations are obtained using an analytical model. The parameters of light trapping, as well as the effects of the position of the solar cells on board of the patch, are studied carefully. Simulation and experimental results validate that the combined harvesting system is a promising candidate for autonomous operation of some sensors and small devices. Indeed, the efficiency of the rectenna is enhanced greatly from 21to 74 % when combined with the solar cells.

Conceptual design of autonomous emergency operation system for nuclear power plants and its prototype

Abstract This paper presents a conceptual design for a plant-wide autonomous operation system that uses artificial intelligence techniques. The autonomous operation system has the power and ability to perform the control functions needed for the emergency operation of a nuclear power plant (NPP) with reduced operator intervention. This paper discusses the emergency operation and level of automation in an NPP and presents the design requirements for an autonomous emergency operation system (A-EOS). Then, an architecture that consists of several modules is proposed, with descriptions of the functions. Finally, this paper introduces a prototype of the suggested autonomous system that integrates the authors’ previous works.

Model-based On-board Decision Making for Autonomous Aircraft

Powerful, small and lightweight sensors in combination with advanced failure detection, diagnosis, and prognostics techniques provide up-to-date data on the health status of a Unmanned Aerial System (UAS). In an autonomous UAS, this information must be used for automatic planning and execution of contingency actions to keep the UAS safe in adverse conditions.We present DM (Decision Maker), a software component which uses model-based reasoning, backtracking search to iteratively construct contingency plansthat are safe for the UAS to execute and pose minimal interruption to the mission goals. The DM, which has been developed within the NASA Autonomous Operating System (AOS) project thus fills the gap between Prognostics and Health Management and autonomous flight operations.In this paper, we describe DM and its reasoning/search algorithm and present the supporting modeling framework for the construction of system and fault models. An flight with a DJI S1000+ octocopter with fault injection will be used as our case study.

Design and Operation of Autonomous Underground Freight Transportation Systems

AbstractDespite the increases in freight transportation demand, options for increasing capacity of the overground freight transportation infrastructure system are limited. This paper investigated t...

Optimal planning of electricity storage to minimize operating reserve requirements in an isolated island grid

Electrical energy storage (EES) constitutes a potential candidate capable of regulating the power generation to match the loads via time-shifting. Optimally planned, EES facilities can meet the increasing requirement of reserves to manage the variability and uncertainty of renewable energy sources (RES) whilst improving the system operation efficiency and economics. In this work, the impact of intermittent RES on total production cost (TPC) is evaluated in the presence and absence of storage, using annual data regarding the non-interconnected power system of the island of Cyprus. Performing weekly simulations for the entire year of 2017, TPC is computed by solving the unit commitment based on a constrained Lagrange Relaxation method. Seven selected EES technologies are modeled and evaluated via a life-cycle cost analysis, based on the most realistic technical and cost data found in the literature. The results derived from the uncertainty analysis performed, show that zinc-air (Zn-air) battery offers the highest net present value (NPV). Lead-acid (Pb-acid) and sodium-sulfur (Na-S) are considered viable solutions in terms of mean NPV and investment risk. Lithium-ion (Li-ion) battery exhibits a particularly expensive choice. Dominated by its increased capital cost which still governs its overall cost performance Li-ion achieves a negative mean NPV far below zero. However, to strengthen the benefits derived from EES integration, further research and development is needed improving the performance and costs of storage. The uncertainty governing the majority of EES technologies, in turn, will be reduced, increasing their participation and RES contribution in autonomous power system operations.

Energy analysis of Bahrain’s first hybrid renewable energy system

ABSTRACTIn 2011, Bahrain Petroleum Company inaugurated the country’s first Hybrid Renewable Energy System (HRES) as a demonstration project, which partially supplies the electricity required for the reception hall of the company’s park. Data collected from the system for a full year were analyzed to assess the performance of this grid-connected HRES, which comprises of two primary renewable energy sources – a photovoltaic panel and a wind turbine – with a total-rated capacity of 5.7 kW and three secondary/backup systems – batteries, hydrogen/fuel cell, and public grid. This article presents the results of the conducted analysis which included assessment of the energy supply and demand, the different components’ efficiencies, the effect of dust on the PV panel performance, the contribution of the batteries, hydrogen storage system, and the fuel cell, the amount of CO2 avoided and emitted due to operation, the cost of energy produced, and finally upgrading the system for autonomous operation. Although the system was not economically feasible, it well served the community by creating public awareness of renewable energy and by providing an opportunity for researchers to gain hands-on experience of different renewable energy technologies and to study the challenges associated to implementing such technologies in the region.

A novel multicopter with improved torque disturbance rejection through added angular momentum

This paper presents a novel multicopter design with an additional momentum wheel. The added angular momentum reduces the vehicle’s sensitivity to torque disturbances compared to a conventional multicopter. The mechanical design, coupled with intelligent feedback control, allows for operation of autonomous aerial systems in challenging environments where conventional designs may fail. Sensitivity to torque disturbances is shown to monotonically decrease with increasing angular momentum, and the effect scales such that a greater improvement in torque disturbance sensitivity is experienced by smaller vehicles. For a fixed vehicle size, a trade-off exists between the added torque disturbance rejection capability, the power required to carry the wheel’s added mass, and the kinetic energy of the rotating wheel. A cascaded controller structure is proposed that accounts for the additional angular momentum and that accelerates or decelerates the momentum wheel to gain additional control authority in yaw. Theoretical results are validated experimentally using two vehicles of different scales. The proposed vehicle design is likely to be of value in situations where precision control is required in the face of large disturbances.

Two 0.5-m robotic telescopes for Timau National Observatory in eastern Indonesia

Timau National Observatory will be the new Indonesia’s astronomical observatory in East Nusa Tenggara, planned for 2020. Besides the main 3.8-m optical telescope, it will host two 0.5-m “off-the-shelf” f/3.8 and f/8.0 telescopes, equipped with two CCD cameras and two filter wheels. The system will be controlled with a robotic system for autonomous operation. In this paper, we present the system description and current development progress, as well as the future plan for the facility, including its two potential scientific studies: near-Earth objects and exoplanetary transits.