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1
Sonoura, Takafumi, Seiji Tokura, Tsuyoshi Tasaki, Fumio Ozaki, and Nobuto Matsuhira. "Reflective Collision Avoidance for Mobile Service Robot in Person Coexistence Environment." Journal of Robotics and Mechatronics 23, no. 6 (December 20, 2011): 999–1011. http://dx.doi.org/10.20965/jrm.2011.p0999.
Повний текст джерелаАнотація:
A person coexistence environment is always changing. For example, people in the environment move around, someone changes the arrangement of the furniture, and someone puts something on the floor. Tasks of a service robot to support people include many scenes that the robot should move around in this environment. Without sensing the objects in the environment, it is difficult for an autonomous robot to move in the person coexistence environment protecting a people’s safety. Thus, an advanced ability to avoid collisions by adapting to the environment is required for a robot. From the viewpoint of robustness, a reflective collision avoidance algorithm has been used with predefined map-based path planning. However, because the algorithm is composed of simple operation rules, a robot depending on the reflective collision avoidance algorithm may often moves inefficiently. To ensure efficient collision avoidance, we propose a reflective collision avoidance technique that corrects direction and magnitude of robot velocity independently using 1-dimensional potential-like functions ruled by a pseudo distance that modifies its own distance in proportion to an angle from the robot traveling direction to the obstacle direction. We verify the effectiveness of the proposed technique for a robot developed to serve persons in a retail store.
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Krile, Srećko, Dragan Peraković, and Vladimir Remenar. "Possible Collision Avoidance with Off-line Route Selection." PROMET - Traffic&Transportation 21, no. 6 (March 2, 2012): 403–11. http://dx.doi.org/10.7307/ptt.v21i6.257.
Повний текст джерелаАнотація:
The paper describes the traffic flow problems in telecommunication networks based on the Internet protocol. The main aim of telecommunication network operator today is to offer an SLA (Service Level Agreement) contract to end users, with provided QoS (Quality of Service) for different classes of services. In order to achieve this, it is necessary to establish the routes between marginal network nodes meeting the network traffic requirements and optimizing the network performances free of simultaneous flows conflicts. In DiffServ/MPLS (Multi-Protocol Label Switching) networks traffic flows traverse the network simultaneously and there may come to collision of concurrent flows. They are distributed among LSPs (Labeled Switching Paths) related to service classes. In LSP creation the IGP (Interior Gateway Protocol) uses simple on-line routing algorithms based on the shortest path methodology. In highly loaded networks this becomes an insufficient technique. In this suggested approach LSP need not necessarily be the shortest path solution. It can be pre-computed much earlier, possibly during the SLA negotiation process. In that sense an effective algorithm for collision control is developed. It may find a longer but lightly loaded path, taking care of the collision possibility. It could be a very good solution for collision avoidance and for better load-balancing purpose where links are running close to capacity. The algorithm can be significantly improved through heuristic approach. Heuristic options are compared in test-examples and their application for collision control is explained. KEYWORDS: Telecommunication networks, collision avoidance, multi-constraint route selection, self-organizing systems, MPLS, QoS
3
Kao, Sheng-Long, Kuo-Tien Lee, Ki-Yin Chang, and Min-Der Ko. "A Fuzzy Logic Method for Collision Avoidance in Vessel Traffic Service." Journal of Navigation 60, no. 1 (December 15, 2006): 17–31. http://dx.doi.org/10.1017/s0373463307003980.
Повний текст джерелаАнотація:
Currently Vessel Traffic Service (VTS) does not have enough technical capability to monitor a crowded surveillance area to maintain safety. Without an efficient alerting system, many marine accidents have occurred due to operator oversight. In this article, a new fuzzy logic method is proposed to add vessel collision avoidance capability to VTS/AIS systems for all potential collision ships in the surveillance area. Starting from the VTS standpoint and integrating AIS data into the Marine Geographic Information System (MGIS) as a platform, the calculations of ship domain and ship inertial force are utilized to generate models of a guarding ring and danger index. By this means, a precise prediction of collision time and position can be achieved using a marine GIS spatial analyst module. The proposed method is able to enhance the VTS operator's decision-making abilities by providing a collision avoidance alerting system.
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Tropea, Mauro, Floriano De Rango, Nicolas Nevigato, Luigi Bitonti, and Francesco Pupo. "SCARE: A Novel Switching and Collision Avoidance pRocEss for Connected Vehicles Using Virtualization and Edge Computing Paradigm." Sensors 21, no. 11 (May 24, 2021): 3638. http://dx.doi.org/10.3390/s21113638.
Повний текст джерелаАнотація:
In this paper, some collision avoidance systems based on MEC in a VANET environment are proposed and investigated. Micro services at edge are considered to support service continuity in vehicle communication and advertising. This considered system makes use of cloud and edge computing, allowing to switch communication from edge to cloud server and vice versa when possible, trying to guarantee the required constraints and balancing the communication among the servers. Simulation results were used to evaluate the performance of three considered mechanisms: the first one considering only edge with load balancing, the second one using edge/cloud switching and the third one using edge with load balancing and collision avoidance advertising.
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Hinsch, Werner. "Risk of Collision at Sea." Journal of Navigation 48, no. 3 (September 1995): 389–95. http://dx.doi.org/10.1017/s0373463300015277.
Повний текст джерелаАнотація:
Vessel traffic service systems (VTS systems) have been established, throughout the world, in areas of high traffic density. These systems, operating with such tools as VHF radiotelephony, land-based radar installations and ship's data processing, gather information to respond to collision and grounding danger, to organize traffic flow and assist allied activities. It is expected that VTS systems should effectively reduce the number of collisions in the VTS area. But efforts for collision avoidance can only be successful if the VTS operator in front of the shoreside radar screen is precisely instructed as to which measurements he has to make to identify a risk-of-collision situation. Uncertainties about the direction in which ships must take evasive action arise in VTS areas, where ships are free to engage in encounters.
6
Baek, Min, Hwan Lee, Hyojin Choi, and Kyunbyoung Ko. "Development of Intersection Collision Avoidance Algorithm for B2V Safety Service." International Journal of Control and Automation 8, no. 12 (December 31, 2015): 229–40. http://dx.doi.org/10.14257/ijca.2015.8.12.21.
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Brooker, Peter. "STCA, TCAS, Airproxes and Collision Risk." Journal of Navigation 58, no. 3 (August 19, 2005): 389–404. http://dx.doi.org/10.1017/s0373463305003334.
Повний текст джерелаАнотація:
The focus here is on the performance of and interaction between the Traffic Alert and Collision Avoidance System (TCAS) and the controller's short-term conflict alert (STCA) system. The data source used is UK Airprox Board Reports of close encounters between aircraft, and the focus is on commercial air transport aircraft using UK controlled airspace with a radar service. Do the systems work well together? Are controllers surprised when they find out that a pilot has received a TCAS resolution advisory? What do TCAS and STCA events say about collision risk? Generally, the systems seem to work together well. On most occasions, controllers are not surprised by TCAS advisories: either they have detected the problem themselves or STCA has alerted them to it. The statistically expected rate of future mid-air collisions is estimated by extrapolation of Airprox closest encounter distances.
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Sun, Hongliang, Xuefen Chi, and Baozhu Yu. "A Grouping Algorithm for Random Access Networks and Supermartingale Evaluation." Wireless Communications and Mobile Computing 2022 (September 9, 2022): 1–11. http://dx.doi.org/10.1155/2022/2554226.
Повний текст джерелаАнотація:
Wireless communications play a critical role in the applications of Internet of Things (IoT). The Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) is a well-proven wireless random access protocol. A crucial factor affecting the performance of random access networks is “hidden node collision,” which incurs performance degradation and lower resource utilization. Grouping is an efficient strategy for hidden node avoidance. In current IoT networks, the terminals usually have different traffic load, so load balance should be considered when grouping algorithm is designed. To mitigate hidden nodes and achieve load balance simultaneously, we propose a grouping algorithm based on the game theory. By introducing the supermartingale theory, the delay performance of the completed groups is analyzed. Simulations prove that the proposed algorithm alleviates collision, balances traffic, and promotes the efficient guarantee for Quality of Service (QoS).
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Shin, Seok-Hoon, Tae-Hyun Hwang, Seung-A. Shin, In-Ho No, Joo-Bo Shim, Mi-Sun Oh, Joo-Young Ko, and Jae-Chang Shim. "Advanced Protocols and Methods of Robot Collision Avoidance for Social Network Service." Journal of Korea Multimedia Society 15, no. 7 (July 31, 2012): 931–40. http://dx.doi.org/10.9717/kmms.2012.15.7.931.
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Arokiasami, Willson Amalraj, Prahlad Vadakkepat, Kay Chen Tan, and Dipti Srinivasan. "Real-Time Path-Generation and Path-Following Using an Interoperable Multi-Agent Framework." Unmanned Systems 06, no. 04 (October 2018): 231–50. http://dx.doi.org/10.1142/s2301385018500061.
Повний текст джерелаАнотація:
Autonomous unmanned vehicles are preferable in patrolling, surveillance and, search and rescue missions. Multi-agent architectures are commonly used for autonomous control of unmanned vehicles. Existing multi-robot architectures for unmanned aerial and ground robots are generally mission and platform oriented. Collision avoidance, path-planning and tracking are some of the fundamental requirements for autonomous operation of unmanned robots. Though aerial and ground vehicles operate differently, the algorithms for obstacle avoidance, path-planning and path-tracking can be generalized. Service Oriented Interoperable Framework for Robot Autonomy (SOIFRA) proposed in this work is an interoperable multi-agent framework focused on generalizing platform independent algorithms for unmanned aerial and ground vehicles. SOIFRA is behavior-based, modular and interoperable across unmanned aerial and ground vehicles. SOIFRA provides collision avoidance, and, path-planning and tracking behaviors for unmanned aerial and ground vehicles. Vector Directed Path-Generation and Tracking (VDPGT), a vector-based algorithm for real-time path-generation and tracking, is proposed in this work. VDPGT dynamically adopts the shortest path to the destination while minimizing the tracking error. Collision avoidance is performed utilizing Hough transform, Canny contour, Lucas–Kanade sparse optical flow algorithm and expansion of object-based time-to-contact estimation. Simulation and experimental results from Turtlebot and AR Drone show that VDPGT can dynamically generate and track paths, and SOIFRA is interoperable across multiple robotic platforms.
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Chappell, Sheryl L., Barry C. Scott, and Charles E. Billings. "Information Transfer in Pilots' Use of a Collision Avoidance System." Proceedings of the Human Factors Society Annual Meeting 31, no. 4 (September 1987): 428–31. http://dx.doi.org/10.1177/154193128703100410.
Повний текст джерелаАнотація:
This paper describes a study of pilots' use of the Traffic-alert and Collision Avoidance System. Three levels of information on the location of other air traffic were presented to different groups of airline pilots. (These levels represent the approaches taken by several airlines who have installed the collision avoidance system for an in-service evaluation.) Current airline flight crews flew a Boeing 727 simulator for eight flights with a set of encounters with other aircraft. To ensure safe separation from the approaching aircraft, the collision avoidance system commands a climb, a descent, or a reduction in rate of climb or descent. Aircraft separation was effective when the system was in use; no aircraft came within 200 feet vertically and 1000 feet horizontally. No measure of response time showed performance effects across display conditions. Response accuracy, as measured by the overshoot in rate of climb or descent, was significant: the mean for condition 1 (no traffic information) was 2246 feet/minute, condition 2 1220 feet/minute, and condition 3 1304 feet/minute (F=4.57, df=2,64, p<.05). However there were no resultant differences in the amount of altitude change. No learning effects were observed. Differences in flight experience did not contribute to the performance difference found. The results of this research represent pilot behavior when introduced to the Traffic-alert and Collision Avoidance System. The findings of this program also have more fundamental importance in addressing how much and in what manner information should be presented to flight crews.
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Andreatta, Giovanni, Carla De Francesco, and Luigi De Giovanni. "Algorithms for Smooth, Safe and Quick Routing on Sensor-Equipped Grid Networks." Sensors 21, no. 24 (December 8, 2021): 8188. http://dx.doi.org/10.3390/s21248188.
Повний текст джерелаАнотація:
Automation plays an important role in modern transportation and handling systems, e.g., to control the routes of aircraft and ground service equipment in airport aprons, automated guided vehicles in port terminals or in public transportation, handling robots in automated factories, drones in warehouse picking operations, etc. Information technology provides hardware and software (e.g., collision detection sensors, routing and collision avoidance logic) that contribute to safe and efficient operations, with relevant social benefits in terms of improved system performance and reduced accident rates. In this context, we address the design of efficient collision-free routes in a minimum-size routing network. We consider a grid and a set of vehicles, each moving from the bottom of the origin column to the top of the destination column. Smooth nonstop paths are required, without collisions nor deviations from shortest paths, and we investigate the minimum number of horizontal lanes allowing for such routing. The problem is known as fleet quickest routing problem on grids. We propose a mathematical formulation solved, for small instances, through standard solvers. For larger instances, we devise heuristics that, based on known combinatorial properties, define priorities, and design collision-free routes. Experiments on random instances show that our algorithms are able to quickly provide good quality solutions.
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Zhang, Jianxia, Jianxin Zhang, Qiang Zhang, and Xiaopeng Wei. "Obstacle Avoidance Path Planning of Space Robot Based on Improved Particle Swarm Optimization." Symmetry 14, no. 5 (May 5, 2022): 938. http://dx.doi.org/10.3390/sym14050938.
Повний текст джерелаАнотація:
In order to meet security requirements of space on orbit service, an obstacle avoidance trajectory planning method using improved particle swarm optimization had been presented in this paper. On the basis of the actual overall structure of 7 degrees of freedom redundant space manipulator and the characteristics of obstacles, the envelope method was used to model the arm and obstacles, respectively. The limit conditions to avoid the collision between them were analyzed. Then, the fitness function under the symmetrical conditions of avoiding the collision and searching for the shortest trajectory was constructed. In addition, the obstacle avoidance trajectory planning was solved based on improved particle swarm optimization (IPSO). Finally, simulation experiments were carried out to prove its effectiveness and rationality, where there were symmetrical advantages in two aspects. It can be concluded that the presented method based on IPSO has strong robustness.
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Al-Rubaye, Wisam I., Dhiaa S. Ghanem, Ali M. Saleem, and Hayder A. Al-Attabi. "Anti-collision Analysis of Pad Drilling and Optimization of Wellbore Trajectory: A Field Case Study." Journal of Petroleum Research and Studies 12, no. 2 (June 21, 2022): 1–12. http://dx.doi.org/10.52716/jprs.v12i2.654.
Повний текст джерелаАнотація:
Errors can occur in the wellbore position according to the fact the survey tools are not completely accurate; therefore, prediction of well path position is imperative for safe and cost-effective drilling operation. The aim of this paper is an analysis of collision avoidance as well as assessment and optimization of wellbore trajectory for minimizing the risk of collision by applying different anti-collision and planning techniques. Thus, anti-collision analysis of pad drilling in the Iraqi oil field has been investigated using Industry Steering Committee for Wellbore Survey Accuracy (ISCWSA) error model to estimate the wellbores position and assess their separation using different techniques available in the industry. Three actual offset wells X1, X2, X3, and one proposed principal X4 well in a drilling pad have been used in the collision avoidance model. Separation factor, ladder, and travel cylinder plots revealed a high possibility of X4 proposed well colliding with X3 actual offset well. The separation factor of 0.75 and 7.5 m center to center prove that the current design of X4 principal design doesn’t meet the anti-collision standards, accordingly, a design revision must be highly considered. The field operator hasn’t revised the well design due to the lack in the assessment of anti-collision risks, thus, the survey service company has advised the operator to modify the predetermined well trajectory due to major risk of collision with X3 offset well and the well has been sidetracked. After reviewing and optimizing the well trajectory by using slant and optimum align (curve hold curve) planning methods, the anti-collision results have been greatly improved. The results showed that, through adopting an adequate anti-collision risk assessment and the modified well design, problems associated with the execution of the improper well design could be totally eliminated.
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Soule, Heidi H., Skip Huck, Andrew Krum, Yinhai Wang, Ruimin Ke, Dave Valadez, Dan Sellers, and Jerome M. Lutin. "Testing an Automated Collision Avoidance and Emergency Braking System for Buses." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 4 (March 19, 2020): 66–74. http://dx.doi.org/10.1177/0361198120912431.
Повний текст джерелаАнотація:
In 2017 the Federal Transit Administration (FTA) awarded Pierce Transit of Lakewood, WA a $1.66 million grant for a bus collision avoidance and mitigation safety research and demonstration project. The project scope includes installation of an advanced technology package, the Pedestrian Avoidance Safety System (PASS) that uses lidar sensors to trigger an automated deceleration and braking system. An “alpha testing” phase included shipping a Pierce Transit bus to Blacksburg, VA for closed-course testing of PASS on Virginia Tech Transportation Institute’s (VTTI’s) Smart Road facility. In addition, VTTI developed a system to observe, measure, and analyze passenger motion during braking events. Following completion of testing at VTTI, the bus will be returned to Pierce Transit. Together with three additional buses currently being outfitted with PASS, all four will be equipped with Transit Event Logging System (TELS) video processers developed by University of Washington’s Smart Transportation Applications & Research (STAR) Lab to analyze PASS accuracy for “false positives” and “false negatives.” Upon successful completion of in-service engineering testing of the initial four buses, an additional 26 buses will be equipped with PASS and all 30 will be monitored using telematics for a year-long demonstration. This paper discusses project background and organization, describes the PASS being tested, provides an overview of the alpha testing, describes project data collection processes, and reviews the criteria and metrics being used to evaluate the system. The paper concludes with observations about lessons learned to date.
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Politis, Anastasios C., and Hristos T. Anastassiu. "Performance Analysis of Resource Sharing During Downlink Multi-User Transmissions in CSMA/ECA Full Duplex WLANs." Transport and Telecommunication Journal 21, no. 1 (February 1, 2020): 61–68. http://dx.doi.org/10.2478/ttj-2020-0005.
Повний текст джерелаАнотація:
AbstractFull Duplex (FD) wireless communications is considered to be the next big step for future Wireless Local Area Networks (WLANs). Old (IEEE 802.11ac) and new (IEEE 802.11ax) WLAN features are expected to co-exist with FD operation. Some of these features include Downlink Multi-User (DL MU) transmissions at the physical layer while at the Medium Access Control (MAC) layer techniques such as the Transmission Opportunity (TXOP) sharing mechanism facilitates these multiuser transmissions. The traditional Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol is inadequate to support full duplex communications efficiently. A very promising adaptation of CSMA/CA and a powerful candidate as the basic channel access method for future WLANs is the Carrier Sense Multiple Access with Enhanced Collision Avoidance (CSMA/ECA). In this paper, we provide an analytical model to assess the performance of resource sharing techniques in full duplex WLANs operating with the CSMA/ECA protocol. Our analysis is based on Markov chains to obtain an estimate of the achievable throughput of the Quality of Service Access Point (QAP) during DL MU transmissions.
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Vasylyev, V. V., L. A. Godunok, and S. A. Matviienko. "On orbit serving — a step towards further exploration of near-Earth space." Kosmìčna nauka ì tehnologìâ 27, no. 3 (July 2021): 39–50. http://dx.doi.org/10.15407/knit2021.03.039.
Повний текст джерелаАнотація:
The purpose of the publication is to draw the attention of the Ukrainian scientific and technical community to the development of a new area of activity in outer space - orbital service. The content, technical and economic preconditions and competitive advantages of its development in Ukraine are outlined. Definitions of orbital services such as customer inspection, orbital (inter-orbital) transportation, refueling and resupply, upgrade, assembly, collision avoidance are given. The competence of Ukrainian enterprises in this direction has been analyzed. The expediency and possibility of developing the direction of orbital servicing for further exploration of near space, in particular, the developments of Ukrainian enterprises for the development and manufacture of systems for rendezvous and docking of spacecraft, have been substantiated. Scenarios of interaction between a space service vehicle and a client vehicle in near-earth orbit are described. The basic requirements for carrying out of Servicer and the Client autonomous proximity operations, as well as the operation of seizing the client machine are given. Proposals for the functionality of spacecraft for the provision of orbital space services are presented, it is proposed to consider the need to create specialized cargo modules and examples of their application in orbit are given. The tendencies of the approach to the creation of spacecraft structures adapted for in-orbit service are considered. The predicted volume of orbital service operations by type of service and with orbits is given. Provided information about the key players in a given market. The design of Servicer, which is being developed by Kurs NPK JSC, Yuzhnoye Design Bureau, for the provision of transport services, is presented. The specified features of its construction in general and the composition of the modules, as well as the possibility of further expanding the functionality of the Servicer.
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Wu, Chunlong, Hanyu Lv, Tianming Zhu, Yunhe Liu, and Marcus Vinicius Pereira Pessôa. "Conceptual Modeling of Extended Collision Warning System from the Perspective of Smart Product-Service System." Sensors 22, no. 12 (June 20, 2022): 4654. http://dx.doi.org/10.3390/s22124654.
Повний текст джерелаАнотація:
While Product-Service Systems (PSS) have a potential sustainability impact by increasing a product’s life and reducing resource consumption, the lack of ownership might lead to less responsible user behavior. Smart PSS can overcome this obstacle and guarantee correct and safe PSS use. In this context, intelligent connected vehicles (ICVs) with PSS can effectively reduce traffic accidents and ensure the safety of vehicles and pedestrians by guaranteeing optimal and safe vehicle operation. A core subsystem to support that is the collision-warning system (CWS). Existing CWSs are, however, limited to in-car warning; users have less access to the warning information, so the result of CWS for collision avoidance is insufficient. Therefore, CWS needs to be extended to include more elements and stakeholders in the collision scenario. This paper aims to provide a novel understanding of extended CWS (ECWS), outline the conceptual framework of ECWS, and contribute a conceptual modeling approach of ECWS from the smart PSS perspective at the functional level. It defines an integrated solution of intelligent products and warning services. The function is modeled based on the Theory of Inventive Problem Solving (TRIZ). Functions of an ECWS from the perspective of smart PSS can be comprehensively expressed to form an overall solution of integrated intelligent products, electronic services, and stakeholders. Based on the case illustration, the proposed method can effectively help function modeling and development of the ECWS at a conceptual level. This can effectively avoid delays due to traffic accidents and ensure the safety of vehicles and pedestrians.
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Xia, Feng, Jie Li, Ruonan Hao, Xiangjie Kong, and Ruixia Gao. "Service Differentiated and Adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems." Scientific World Journal 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/947808.
Повний текст джерелаАнотація:
Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay.
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HASHIMOTO, Ken, Takashi YOSHIMI, Makoto MIZUKAWA, Yoshinobu ANDO, Shin'ichi YUTA, and Kiyoaki TAKEUCHI. "1A1-O01 A study of collision avoidance at corner between the service robot and the human : Second Report: the proposal and evaluation of service robot's collision avoidance trajectory considered human's behavior(Robots for Home/Office Application)." Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2014 (2014): _1A1—O01_1—_1A1—O01_3. http://dx.doi.org/10.1299/jsmermd.2014._1a1-o01_1.
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Pedersen, Casper Bak, Kasper Rosenkrands, Inkyung Sung, and Peter Nielsen. "Systemic Performance Analysis on Zoning for Unmanned Aerial Vehicle-Based Service Delivery." Drones 6, no. 7 (June 26, 2022): 157. http://dx.doi.org/10.3390/drones6070157.
Повний текст джерелаАнотація:
A zoning approach that divides an area of interest into multiple sub-areas can be a systemic and strategic solution to safely deploy a fleet of unmanned aerial vehicles (UAVs) for package delivery services. Following the zoning approach, a UAV can be assigned to one of the sub-areas, taking sole ownership and responsibility of the sub-area. As a result, the need for collision avoidance between units and the complexity of relevant operational activities can be minimized, ensuring both safe and reliable execution of the tasks. Given that the zoning approach involves the demand-server allocation decision, the service quality to customers can also be improved by performing the zoning properly. To illuminate the benefits of the zoning approach to UAV operations from a systemic perspective, this study applies clustering techniques to derive zoning solutions under different scenarios and examines the performance of the solutions using a simulation model. The simulation results demonstrate that the zoning approach can improve the safety of UAV operations, as well as the quality of service to demands.
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Gao, Ying, Yangliang Liu, Quansi Wen, Hongliang Lin, and Yijian Chen. "Secure Drone Network Edge Service Architecture Guaranteed by DAG-Based Blockchain for Flying Automation under 5G." Sensors 20, no. 21 (October 30, 2020): 6209. http://dx.doi.org/10.3390/s20216209.
Повний текст джерелаАнотація:
With the development of the Internet of Things (IoT), the number of drones, as a consumer-level IoT device, is rapidly increasing. The existence of a large number of drones increases the risk of misoperation during manual control. Therefore, it has become an inevitable trend to realize drone flying automation. Drone flying automation mainly relies on massive drone applications and services as well as third-party service providers, which not only complicate the drone network service environment but also raise some security and privacy issues. To address these challenges, this article proposes an innovative architecture called Secure Drone Network Edge Service (SDNES), which integrates edge computing and blockchain into the drone network to provide real-time and reliable network services for drones. To design a feasible and rational SDNES architecture, we first consider the real-time performance and apply edge computing technology in it to provide low-latency edge services for drones under 5G mobile network. We use DAG-based blockchain to guarantee the security and reliability of the drone network service environment and effectively avoid malicious behaviors. In order to illustrate the feasibility of this architecture, we design and implement a specific service case named Drone Collision Avoidance Navigation Service based on SDNES. Finally, a simulation experiment for the specific service case and a series of other performance-related experiments were carried out to verify the feasibility and rationality of our proposed architecture. The experimental results demonstrate that SDNES is a promising architecture to assist and accelerate drone flying automation.
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Liu, Xuan, Kashif Nazar Khan, Qamar Farooq, Yunhong Hao, and Muhammad Shoaib Arshad. "Obstacle Avoidance through Gesture Recognition: Business Advancement Potential in Robot Navigation Socio-Technology." Robotica 37, no. 10 (March 20, 2019): 1663–76. http://dx.doi.org/10.1017/s0263574719000183.
Повний текст джерелаАнотація:
SummaryIn the present modern age, a robot works like human and is controlled in such a manner that its movements should not create hindrance in human activities. This characteristic involves gesture feat and gesture recognition. This article is aimed to describe the developments in algorithms devised for obstacle avoidance in robot navigation which can open a new horizon for advancement in businesses. For this purpose, our study is focused on gesture recognition to mean socio-technological implication. Literature review on this issue reveals that movement of robots can be made efficient by introducing gesture-based collision avoidance techniques. Experimental results illustrated a high level of robustness and usability of the Gesture recognition (GR) system. The overall error rate is almost 10%. In our subjective judgment, we assume that GR system is very well-suited to instruct a mobile service robot to change its path on the instruction of human.
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Szlapczynski, Rafal. "A New Method of Ship Routing on Raster Grids, with Turn Penalties and Collision Avoidance." Journal of Navigation 59, no. 1 (January 2005): 27–42. http://dx.doi.org/10.1017/s0373463305003528.
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The article introduces a method of finding optimal routes on raster planes. The method presented takes advantage of a new algorithm that tends to minimize a number of direction changes within a route, while steering clear of the obstacles. Two different schemes, suitable for restricted area Vessel Traffic Service (VTS) system and collision avoidance system located on the own ship are described. The VTS-oriented scheme supports VTS priority policy that may extend or override international give-way regulations. The own-ship routing scheme in a give-way situation is capable of determining the shortest safe path to the destination point. The method takes into account own ship dynamics. It has linear time and space complexities and therefore is sufficiently fast to perform real-time routing on the raster grids. Both the general method and the algorithm it uses are presented in detail in the paper. Implementation issues are also discussed.
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Abdel-Ameer, Zaynab Mahir, Abdul Kareem A. Najem Alaloosy, and Khattab M. Ali Alheeti. "Performance analysis and evaluation of IEEE 802.11 distributed coordination function using OPNET." Bulletin of Electrical Engineering and Informatics 9, no. 6 (December 1, 2020): 2595–600. http://dx.doi.org/10.11591/eei.v9i6.2477.
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This paper discusses the distributed coordination function (DCF) access mechanism which is a carrier sense multiple access with collision avoidance (CSMA/CA) scheme. Simulation projects for different DCF performance parameters have been built using the OPNET network simulator. The projects are mainly basic service set (BSS) topology simulated under different parameter values (data rate, fragmentation, RTS/CTS, number of nodes, and load condition). Simulation results show when the DCF access mechanism is better under what load condition, and how to choose the best fragmentation threshold and other access-mechanism specific parameters according to the network conditions. Simulation results were validated against a theoretically calculated maximum throughput (the simulation maximum throughput was about 70% of the theoretically calculated maximum throughput).
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Khan, Pervez, Niamat Ullah, Md Nasre Alam, and Kyung Sup Kwak. "Performance Analysis of WBAN MAC Protocol under Different Access Periods." International Journal of Distributed Sensor Networks 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/102052.
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The IEEE 802.15.6 is a new standard on wireless body area network (WBAN) for short-range, extremely low power wireless communication with high data rates in the vicinity of, or inside, a human body. The standard defines two contention-based channel access schemes: slotted ALOHA and carrier sense multiple access with collision avoidance (CSMA/CA) using an alternative binary exponential backoff procedure. The standard supports quality of service (QoS) differentiation through user priorities and access phases. In this study, we develop an analytical model for the estimation of performance metrics such as energy consumption, normalized throughput, and mean frame service time, employing a Markov chain model under nonsaturated heterogeneous traffic scenarios including different access phases specified in the standard for different user priorities and access methods. We conclude that the deployment of exclusive access phase (EAP) is not necessary in a typical WBAN using CSMA/CA because it degrades the overall system throughput, consumes more energy per packet, and results in higher delay for nonemergency nodes.
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Kousaridas, Apostolos, Andreas Schimpe, Sebastian Euler, Xavier Vilajosana, Mikael Fallgren, Giada Landi, Francesca Moscatelli, et al. "5G Cross-Border Operation for Connected and Automated Mobility: Challenges and Solutions." Future Internet 12, no. 1 (December 24, 2019): 5. http://dx.doi.org/10.3390/fi12010005.
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The vision of cooperative, connected and automated mobility (CCAM) across Europe can only be realized when harmonized solutions that support cross-border traffic exist. The possibility of providing CCAM services along different countries when vehicles drive across various national borders has a huge innovative business potential. However, the seamless provision of connectivity and the uninterrupted delivery of services along borders also poses interesting technical challenges. The situation is particularly innovative given the multi-country, multi-operator, multi-telco-vendor, and multi-car-manufacturer scenario of any cross-border layout. This paper introduces the challenges associated to a cross-border deployment of communication technologies through the analysis of three use cases: tele-operated driving, high-definition map generation and distribution for autonomous vehicles, and anticipated cooperative collision avoidance. Furthermore, a set of 5G solutions have been identified to ensure that CCAM services can be supported efficiently in cross-border scenarios. Faster handover of a data connection from one operator to another, generalized inter-mobile edge computing (MEC) coordination, and quality of service (QoS) prediction are some of the solutions that have been introduced to reduce the uncertainties of a real 5G cross-border deployment.
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Sedar, Roshan, Francisco Vázquez-Gallego, Ramon Casellas, Ricard Vilalta, Raul Muñoz, Rodrigo Silva, Laurent Dizambourg, et al. "Standards-Compliant Multi-Protocol On-Board Unit for the Evaluation of Connected and Automated Mobility Services in Multi-Vendor Environments." Sensors 21, no. 6 (March 17, 2021): 2090. http://dx.doi.org/10.3390/s21062090.
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Vehicle-to-everything (V2X) communications enable real-time information exchange between vehicles and infrastructure, which extends the perception range of vehicles beyond the limits of on-board sensors and, thus, facilitating the realisation of cooperative, connected, and automated mobility (CCAM) services that will improve road safety and traffic efficiency. In the context of CCAM, the successful deployments of cooperative intelligent transport system (C-ITS) use cases, with the integration of advanced wireless communication technologies, are effectively leading to make transport safer and more efficient. However, the evaluation of multi-vendor and multi-protocol based CCAM service architectures can become challenging and complex. Additionally, conducting on-demand field trials of such architectures with real vehicles involved is prohibitively expensive and time-consuming. In order to overcome these obstacles, in this paper, we present the development of a standards-compliant experimental vehicular on-board unit (OBU) that supports the integration of multiple V2X protocols from different vendors to communicate with heterogeneous cloud-based services that are offered by several original equipment manufacturers (OEMs). We experimentally demonstrate the functionalities of the OBU in a real-world deployment of a cooperative collision avoidance service infrastructure that is based on edge and cloud servers. In addition, we measure end-to-end application-level latencies of multi-protocol supported V2X information flows to show the effectiveness of interoperability in V2X communications between different vehicle OEMs.
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Yin, Jing, Jiahao Li, Yifan Fang, and Ahui Yang. "Service scheduling optimization for multiple tower cranes considering the interval time of the cross-tasks." Mathematical Biosciences and Engineering 20, no. 3 (2023): 5993–6015. http://dx.doi.org/10.3934/mbe.2023259.
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<abstract> <p>The key issues that have always affected the production yield of the construction industry are delays and cost overruns, especially when dealing with large-scale projects and super-high buildings in which multiple tower cranes with overlapping areas are often deployed because of urgent due date and limited space. The service scheduling of tower cranes, which act as the crucial site equipment for lifting and transporting materials, is one of the main problems not only related to the construction progress and project cost but also affecting equipment health, and it may bring security risks. The current work presents a multi-objective optimization model for a multiple tower cranes service scheduling problem (MCSSP) with overlapping areas while achieving maximum interval time of cross-tasks and minimum makespan. For the solving procedure, NSGA-Ⅱ is employed with double-layer chromosome coding and simultaneous coevolutionary strategy design, which can obtain a satisfactory solution through effectively allocating tasks within overlapping areas to each crane and then prioritizing all the assigned tasks. The makespan was minimized, and stable operation of tower cranes without collision was achieved by maximizing the cross-tasks interval time. A case study of the megaproject Daxing International Airport in China has been conducted to evaluate the proposed model and algorithm. The computational results illustrated the Pareto front and its non-dominant relationship. The Pareto optimal solution outperforms the results of the single objective classical genetic algorithm in terms of overall performance of makespan and interval time of cross-tasks. It also can be seen that significant improvement in the time interval of cross-tasks can be achieved at the cost of a tiny increase in makespan, which means effective avoidance of the tower cranes entering the overlapping area at the same time. This can help eliminate collision, interference and frequent start-up and braking of tower cranes, leading to safe, stable and efficient operation on the construction site.</p> </abstract>
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Zhou, Guanghong. "Human-Machine Cooperation and Path Planning for Complex Road Conditions." Scientific Programming 2021 (July 6, 2021): 1–11. http://dx.doi.org/10.1155/2021/7262281.
Повний текст джерелаАнотація:
With the rapid development of the information age, the development of industrial robots is also advancing by leaps and bounds. In the scenes of automobile, medicine, aerospace, and public service, we have fully enjoyed the convenience brought by industrial robots. However, with the continuous development of industrial robot-related concepts and technologies, human-computer interaction and cooperation have become the development trend of industrial robot. In this paper, the human-machine cooperation and path optimization of industrial robot in a complex road environment are studied and analyzed. At the theoretical modeling level, firstly, the industrial robot is modeled and obstacle avoidance is analyzed based on the kinematics of industrial robot; thus, an efficient and concise collision detection model of industrial robot is proposed. At the algorithm level, in view of the complex road conditions faced by industrial robots, this paper will study and analyze the obstacle avoidance strategy of human-computer cooperation and real-time path optimization algorithm of industrial robots. Based on the virtual target point algorithm, this paper further improves the problem that the goal of the traditional path planning algorithm cannot be fully covered, so as to propose the corresponding improved path planning algorithm of industrial robots. In the experimental part, based on the existing industrial robot system, the human-machine cooperation and path planning system proposed in this paper are designed. The experimental results show that the algorithm proposed in this paper improves the accuracy of obstacle avoidance by about 10 points and the corresponding convergence speed by about 5% compared with the traditional algorithm and the experimental effect is remarkable.
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Gnanalakshmi, V., Rahul Raaj, and V. Suresh Kumar. "Design of Quad feed end-fire microstrip patch antenna for Airborne Systems." Journal of Physics: Conference Series 2062, no. 1 (November 1, 2021): 012003. http://dx.doi.org/10.1088/1742-6596/2062/1/012003.
Повний текст джерелаАнотація:
Abstract To design a quad feed end-fire microstrip patch antenna for airborne systems. Basically these type of antennas are most helpful for avoiding mid-air collisions between aircraft. The microstrip patch antenna is very small in size and it is less in weight. Due to small size and less weight, it offers an easy design and fabrication process. The microstrip patch antenna has radiating patch on one side and ground on the other side. They operate at microwave frequencies. The low profile structure of microstrip antenna offers its wide use in wireless communication. They are used as communication antenna on missiles. Traffic alert and Collision Avoidance System (TCAS) is an airborne system which is utilized to provide the service as last defense equipment for avoiding mid-air collisions between the aircraft. 1.03 GHz and 1.09 GHz are the transmitting and receiving frequencies of the existing TCAS antenna respectively. In airborne systems, low aerodynamic drag is required. FR4 epoxy is chosen as the substrate material whose dielectric constant is 4.4. 1.06GHz is chosen as the design frequency, since it is centre frequency between 1.03GHz and 1.09GHz. Microstrip patch antenna always radiates in the broadside direction which is along elevation plane. Due to metallic cap, microstrip patch antenna can also radiate in the end fire radiation which is along the azimuth plane. The ground plane must have very large dimensions than the patch. This microstrip patch antenna working at UHF (Ultra High Frequency) band is designed and their parameters like gain, directivity, return loss, VSWR (Voltage Standing Wave Ratio) and radiation pattern have been analyzed and simulated using ANSYS HFSS (High Frequency Structure Stimulator).
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Baz, Mohammed, and Abdullah Baz. "MSAM: Modular Statistical Analytical Model for MAC and Queuing Latency of VLC Networks under ICS Conditions." Electronics 10, no. 12 (June 8, 2021): 1371. http://dx.doi.org/10.3390/electronics10121371.
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Visible Light Communication (VLC) offers distinctive advantages over conventional radio frequency; wide unlicensed spectrum, resistance to electrometric interference and low susceptibility to security risks, are few to name. Excitingly, VLC becomes a cornerstone in several communication systems such as light fidelity, optical camera communication and the Internet of Radio Light. Most of these networks adopt the Carrier Sensing Multiple Access-Collision Avoidance (CSMA-CA) of IEEE 802.15.7, the official standard for the VLC, as a Medium Access Control (MAC) protocol. Motivated by the crucial roles of MAC in shaping the performance of the VLC and the wide variety of operational conditions demanded by the enormous applications, this paper proposes a Modular Statistical Analytical Model (MSAM). The fundamental approach of MSAM is to segregate the interacting stochastic processes imposed by the CSMA-CA protocol into a set of its elementary subprocesses. The MSAM then synthesises these processes in such a way that quantifies their mutual dependency without making a strict assumption on their characteristics; thus, different operational conditions can be assessed without a need to reconstruct the model. Besides, MSAM employs the radiometry and photometry of VLC to derive mathematical expressions describing the hidden and exposed nodes from which the Imperfect Carrier Sensing (ICS) conditions are defined. The MSAM exploits statistical and queuing theorems to model a VLC as a network of G/G/1 queues from which several probability distributions, characterising the operations of VLC from different perspectives, are derived. Inter-departure, queuing, service time and successful service time are the main distributions in conjunction with throughput, total delay, probability of exposed and hidden node collisions, which are the main outputs of MSAM. Validation for the integrity of the MSAM under different scenarios is carried out by conducting a head-to-head comparison between its results and simulation outcomes.
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Haider, Shahab, Ziaul Haq Abbas, Ghulam Abbas, Muhammad Waqas, Shanshan Tu, and Wei Zhao. "A Novel Cross-Layer V2V Architecture for Direction-Aware Cooperative Collision Avoidance." Electronics 9, no. 7 (July 8, 2020): 1112. http://dx.doi.org/10.3390/electronics9071112.
Повний текст джерелаАнотація:
The death toll due to highway crashes is increasing at an alarming rate across the globe. Vehicular Ad Hoc Networks (VANETs) have emerged as a promising solution to prevent crashes by enabling collision avoidance applications. However, a robust and stable collision avoidance application is a cross-layer problem that must address a number of key challenges across all layers of a VANET communication architecture. This paper presents and evaluates a novel VANET protocol suite, named Direction-Aware Vehicular Collision Avoidance (DVCA), which covers application, security services, network, and link layers. DVCA is a vehicle-to-vehicle communication architecture that provides enhanced collision probability computation and adaptive preventive measures for cooperative collision avoidance on bi-directional highways. Moreover, DVCA enables secure, in-time, and reliable dissemination of warning messages, which provides adequate time for vehicles to prevent collisions. Simulation and analytical results demonstrate reasonable reduction in collisions by DVCA, as compared with eminent VANET communication architectures.
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C, Tripti, and Jibukumar M G. "An Enhancement for IEEE 802.11p to Provision Quality of Service with Context Aware Channel Access for the Forward Collision Avoidance Application in Vehicular Ad Hoc Network." Sensors 21, no. 20 (October 19, 2021): 6937. http://dx.doi.org/10.3390/s21206937.
Повний текст джерелаАнотація:
Key application of an intelligent transportation system is traffic safety, and it provides driver assistance. Safety messages are of two types, beacon messages and event messages. The nodes broadcast these messages in the vehicular networks. The system must rely on a robust medium access control (MAC) protocol to support delivery of safety messages. The standard medium access scheme that is used in vehicular networks to provide service differentiation to support various applications is IEEE 802.11p. The emergency event messages should reach the drivers immediately to take necessary steps to avoid casualties on the road. In IEEE 802.11p, both of these messages are considered with the same priority so that no separate differentiation is created. The proposed work focuses on improving the quality of service for forward collision warning applications in intelligent transportation systems. The scheme proposes a priority-based cooperative MAC (PCMAC) for channel access that works on the context of information. Simulation and analytical results validate improved performance of PCMAC in terms of packet delivery ratio, throughput, and average packet delivery delay, as compared with other eminent MAC protocols. The simulation results show that it has a 9% higher improvement in throughput than IEEE 802.11p and has better performance in the increasing number of emergency messages.
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Tsou, Ming-Cheng, Sheng-Long Kao, and Chien-Min Su. "Decision Support from Genetic Algorithms for Ship Collision Avoidance Route Planning and Alerts." Journal of Navigation 63, no. 1 (December 1, 2009): 167–82. http://dx.doi.org/10.1017/s037346330999021x.
Повний текст джерелаАнотація:
When an officer of the watch (OOW) faces complicated marine traffic, a suitable decision support tool could be employed in support of collision avoidance decisions, to reduce the burden and greatly improve the safety of marine traffic. Decisions on routes to avoid collisions could also consider economy as well as safety. Through simulating the biological evolution model, this research adopts the genetic algorithm used in artificial intelligence to find a theoretically safety-critical recommendation for the shortest route of collision avoidance from an economic viewpoint, combining the international regulations for preventing collisions at sea (COLREGS) and the safety domain of a ship. Based on this recommendation, an optimal safe avoidance turning angle, navigation restoration time and navigational restoration angle will also be provided. A Geographic Information System (GIS) will be used as the platform for display and operation. In order to achieve advance notice of alerts and due preparation for collision avoidance, a Vessel Traffic Services (VTS) operator and the OOW can use this system as a reference to assess collision avoidance at present location.
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Wang, Senjie, and Zhengwei He. "A prediction model of vessel trajectory based on generative adversarial network." Journal of Navigation 74, no. 5 (April 26, 2021): 1161–71. http://dx.doi.org/10.1017/s0373463321000382.
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AbstractTrajectory prediction is an important support for analysing the vessel motion behaviour, judging the vessel traffic risk and collision avoidance route planning of intelligent ships. To improve the accuracy of trajectory prediction in complex situations, a Generative Adversarial Network with Attention Module and Interaction Module (GAN-AI) is proposed to predict the trajectories of multiple vessels. Firstly, GAN-AI can infer all vessels’ future trajectories simultaneously when in the same local area. Secondly, GAN-AI is based on adversarial architecture and trained by competition for better convergence. Thirdly, an interactive module is designed to extract the group motion features of the multiple vessels, to achieve better performance at the ship encounter situations. GAN-AI has been tested on the historical trajectory data of Zhoushan port in China; the experimental results show that the GAN-AI model improves the prediction accuracy by 20%, 24% and 72% compared with sequence to sequence (seq2seq), plain GAN, and the Kalman model. It is of great significance to improve the safety management level of the vessel traffic service system and judge the degree of ship traffic risk.
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Alsarhan, Ayoub, Islam Almalkawi, and Yousef Kilani. "A New Covid-19 Tracing Approach using Machine Learning and Drones Enabled Wireless Network." International Journal of Interactive Mobile Technologies (iJIM) 15, no. 22 (November 19, 2021): 111. http://dx.doi.org/10.3991/ijim.v15i22.22623.
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<p class="0abstract">The continuous advancements in wireless network systems have reshaped the healthcare systems towards using emerging communication technologies at different levels. This paper makes two major contributions. Firstly, a new monitoring and tracking wireless system is developed to handle the COVID-19 spread problem. Unmanned aerial vehicles (UAVs), i.e., drones, are used as base stations as well as data collection points from Internet of Things (IoT) devices on the ground. These UAVs are also able to exchange data with other UAVs and cloud servers. Secondly, this paper introduces a new reinforcement learning (RL) framework for learning the optimal signal-aware UAV trajectories under quality of service constraints. The proposed RL algorithm is instrumental in making the UAV movement decisions that maximize the signal power at the receiver and the data collected from the ground agents. Simulation experiments confirm that the system overcomes conventional wireless monitoring systems and demonstrates efficiency especially in terms of flexible continues connectivity, line-of sight visibility, and collision avoidance.</p>
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Peng, Zhiping, Delong Cui, Jinglong Zuo, and Weiwei Lin. "Research on Cloud Computing Resources Provisioning Based on Reinforcement Learning." Mathematical Problems in Engineering 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/916418.
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As one of the core issues for cloud computing, resource management adopts virtualization technology to shield the underlying resource heterogeneity and complexity which makes the massive distributed resources form a unified giant resource pool. It can achieve efficient resource provisioning by using the rational implementing resource management methods and techniques. Therefore, how to manage cloud computing resources effectively becomes a challenging research topic. By analyzing the executing progress of a user job in the cloud computing environment, we proposed a novel resource provisioning scheme based on the reinforcement learning and queuing theory in this study. With the introduction of the concepts of Segmentation Service Level Agreement (SSLA) and Utilization Unit Time Cost (UUTC), we viewed the resource provisioning problem in cloud computing as a sequential decision issue, and then we designed a novel optimization object function and employed reinforcement learning to solve it. Experiment results not only demonstrated the effectiveness of the proposed scheme, but also proved to outperform the common methods of resource utilization rate in terms of SLA collision avoidance and user costs.
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Da, Longchao, and Hua Wei. "CrowdGAIL: A spatiotemporal aware method for agent navigation." Electronic Research Archive 31, no. 2 (2022): 1134–46. http://dx.doi.org/10.3934/era.2023057.
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<abstract><p>Agent navigation has been a crucial task in today's service and automated factories. Many efforts are to set specific rules for agents in a certain scenario to regulate the agent's behaviors. However, not all situations could be in advance considered, which might lead to terrible performance in a real-world application. In this paper, we propose CrowdGAIL, a method to learn from expert behaviors as an instructing policy, can train most 'human-like' agents in navigation problems without manually setting any reward function or beforehand regulations. First, the proposed model structure is based on generative adversarial imitation learning (GAIL), which imitates how humans take actions and move toward the target to a maximum extent, and by comparison, we prove the advantage of proximal policy optimization (PPO) to trust region policy optimization, thus, GAIL-PPO is what we base. Second, we design a special Sequential DemoBuffer compatible with the inner long short-term memory structure to apply spatiotemporal instruction on the agent's next step. Third, the paper demonstrates the potential of the model with an integrated social manner in a multi-agent scenario by considering human collision avoidance as well as social comfort distance. At last, experiments on the generated dataset from CrowdNav verify how close our model would act like a human being in the trajectory aspect and also how it could guide the multi-agents by avoiding any collision. Under the same evaluation metrics, CrowdGAIL shows better results compared with classic Social-GAN.</p></abstract>
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Beggan, C. D., S. Macmillan, W. J. Brown, and S. J. Grindrod. "Quantifying Global and Random Uncertainties in High Resolution Global Geomagnetic Field Models Used for Directional Drilling." SPE Drilling & Completion 36, no. 03 (February 12, 2021): 603–12. http://dx.doi.org/10.2118/204038-pa.
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Summary Total field strength, declination, and dip angle of the Earth's magnetic field, in conjunction with gravity, are used by magnetic-survey tools to determine a wellbore's location. Magnetic field values may be obtained from global models that, depending on the model, have a wide range of spatial resolution at the Earth's surface from large scale (3000 km) to small scale (28 km). The magnetic field varies continuously in both time and space, so no model can fully capture the complexity of all sources; hence, there are uncertainties associated with the values provided. The SPE Wellbore Positioning Technical Section/Industry Steering Committee on Wellbore Surveying Accuracy (ISCWSA) published their original measurement-while-drilling (MWD) error model in 2000. Such models and uncertainties define positional error ellipsoids along the wellbore, which assist the driller in achieving their geological target, in addition to aiding collision avoidance. With the recent update to Revision 5 of the ISCWSA error model, we have reassessed the uncertainties associated with our latest high-resolution global magnetic field model. We describe the derivation of location-specific global and random uncertainties for use with predicted geomagnetic values from high-resolution models within magnetic MWD survey-tool-error models. We propose a sophisticated approach to provide realistic values at different locations around the globe; for example, we determine separate errors for regions where the models have high spatial resolution from aeromagnetic data compared to regions where only satellite data are available. The combined uncertainties are freely available via a web service with which the user can also see how they vary with time. The use of the revised uncertainty values in the MWD-error model, in most cases, reduces the positional error ellipsoids and allows better use of the increased accuracy from recent improvements in geomagnetic modeling. This is demonstrated using the new uncertainty values in the MWD-error model for three standard ISCWSA well profiles. A fourth theoretical well offshore Brazil where the vertical magnetic field is weak shows that with drillstring interference correction relying on the more uncertain magnetic dip, the positional error ellipsoids can increase. This is clearly of concern for attaining geological targets and collision avoidance.
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Heirich, Oliver, Benjamin Siebler, and Erik Hedberg. "Study of Train-Side Passive Magnetic Measurements with Applications to Train Localization." Journal of Sensors 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/8073982.
Повний текст джерелаАнотація:
Passive magnetic sensors measure the magnetic field density in three axes and are often integrated on a single chip. These low-cost sensors are widely used in car navigation as well as in battery powered navigation equipment such as smartphones as part of an electronic compass. We focus on a train localization application with multiple, exclusively onboard sensors and a track map. This approach is considered as a base technology for future railway applications such as collision avoidance systems or autonomous train driving. In this paper, we address the following question: how beneficial are passive magnetic measurements for train localization? We present and analyze measurements of two different magnetometers recorded on a regional train at regular passenger service. We show promising correlations of the measurements with the track positions and the traveled switch way. The processed data reveals that the railway environment has repeatable, location-dependent magnetic signatures. This is considered as a novel approach to train localization, as the use of these magnetic signals at first view is not obvious. The proposed methods based on passive magnetic measurements show a high potential to be integrated in new and existing train localization approaches.
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HASHIMOTO, Ken, Takashi YOSHIMI, Makoto MIZUKAWA, Yoshinobu ANDO, and Kiyoaki TAKEUCHI. "2A2-Q10 A study of collision avoidance at corner between the service robot and the human : First Report: Analysis of human behavior at corner(Robots for Home/Office Application)." Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2013 (2013): _2A2—Q10_1—_2A2—Q10_4. http://dx.doi.org/10.1299/jsmermd.2013._2a2-q10_1.
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Wang, Xun, Zhaokui Wang, and Yulin Zhang. "Model Predictive Control to Autonomously Approach a Failed Spacecraft." International Journal of Aerospace Engineering 2018 (December 6, 2018): 1–18. http://dx.doi.org/10.1155/2018/7428535.
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In this study, a model predictive control (MPC) method is developed for a servicer spacecraft autonomously approaching a tumbling failed spacecraft at an ultraclose range. Flight safety and collision avoidance are basic requirements during the approach. Two types of a failed spacecraft with complex configurations are considered, and a double-ellipsoid composite envelope strategy is designed to model their keep-out zones. Given the keep-out zone of the servicer, two expanded ellipsoids are subsequently introduced to determine the collision and sufficient conditions for collision avoidance are derived by using the form of concave constraint. The tumbling motion of the target is considered, and a CW-based translational dynamics and derived attitude dynamics of the target are formulated to predict the motion of the docking point and keep-out zone. The MPC is formulated to drive the servicer tracking the docking point with collision avoidance and handle constraints including control input saturation and relative velocity bound. Convexification of the collision avoidance constraint and sequential convex programming are adopted for the implementation of MPC. Scenarios on the servicer with different initial positions approaching the target with different angular velocities are simulated, and the simulation results indicate that the proposed MPC method is effective.
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Brooker, Peter. "4D-Trajectory Air Traffic Management: Are There ‘Killer Apps’? – Part 2." Journal of Navigation 65, no. 4 (May 30, 2012): 571–87. http://dx.doi.org/10.1017/s0373463312000173.
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The USA and Europe are developing plans – NextGen and SESAR – to transform the processes of Air Traffic Management (ATM). These will improve safety and efficiency, and match predicted increases in air transportation demand. They use advanced networking technology updated with information from satellite navigation and digital non-voice communication. The strategic goal, envisaged for 15–20 years hence, is a new ATM paradigm. Aircraft would fly on Four-Dimensional (4D) trajectories, incorporating altitude, position, time, and other aircraft positions and vectors. This vision would involve extremely large investments from the airline industry and ATM service providers. Thus, development priorities need to be based on sound business cases. But will these necessarily lead to the strategic vision of a 4D-trajectory system? Will the changes in practice be limited to a series of short and medium term operational improvements rather than strategic improvements? So, are there ‘Killer Apps’ for 4D-trajectory ATM? ‘Killer App(lication)s’ is jargon for innovations so valuable that they prove the core value of some larger technology. Killer Apps generate high degrees of stakeholder technical and financial cooperation. Ironically, most past ATM Killer Apps have improved safety, e.g., modern radar data processing led to collision avoidance systems. The analysis here attempts to identify and then size potential 4D-trajectory ATM Killer Apps. The evidence for Killer Apps has to pass key tests. Killer Apps obviously have to offer enormous benefits to stakeholders in the context of the potential costs. The bulk of these benefits must not be obtainable through technologically ‘cut down’ non−4D-trajectory versions. Part 1 of this paper (Brooker, 2012a) sets out the framework for investigating these questions. Part 2 examines potential Killer Apps derived from improvements in Fuel Efficiency, Capacity and Cost. An abbreviated version of this paper was first presented at the European Navigation Conference (ENC 2011), London in November 2011.
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Abdukarimov, Sirojiddin, and Asadullo Ganiev. "RECENT APPROACHES AND ALGORITHMS TO SOLUTIONS OF THE PROBLEMS OF COLLISION AVOIDANCE OF UNMANNED AERIAL VEHICLES." European International Journal of Multidisciplinary Research and Management Studies 02, no. 05 (May 1, 2022): 188–94. http://dx.doi.org/10.55640/eijmrms-02-05-36.
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An unmanned aerial vehicle (UAV) is an aircraft that is remotely piloted or flown autonomously, without pilot assistance. Historically, UAVs were originally used as military devices: weapons and reconnaissance tools. However, since the early 2000s, UAVs developed for purely civilian purposes rather than military ones have become increasingly important. The civilian application of UAVs is very broad: from the agricultural and entertainment sectors to the oil and gas and security sectors. "Civilian drones can be used by emergency services (fire safety control); law enforcement (patrolling areas, detecting violations); agriculture (crop surveillance), forestry and fishing (forest protection and fishery control); geodesy companies (mapping); geography and geology institutes; oil and gas companies (monitoring of oil and gas facilities); construction companies (inspecting construction.
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H. Sawalmeh, Ahmad, and Noor Shamsiah Othman. "An Overview of Collision Avoidance Approaches and Network Architecture of Unmanned Aerial Vehicles (UAVs)." International Journal of Engineering & Technology 7, no. 4.35 (November 30, 2018): 924. http://dx.doi.org/10.14419/ijet.v7i4.35.27395.
Повний текст джерелаАнотація:
As an autonomous vehicle, Unmanned Aerial Vehicles (UAVs) are subjected to several challenges. One of the challenges is for UAV to be able to avoid collision. Many collision avoidance methods have been proposed to address this issue. Furthermore, in a multi-UAV system, it is also important to address communication issue among UAVs for cooperation and collaboration. This issue can be addressed by setting up an ad-hoc network among UAVs. There is also a need to consider the challenges in the deployment of UAVs, as well as, in the development of collision avoidance methods and the establishment of communication for cooperation and collaboration in a multi-UAV system. In this paper, we present general challenges in the deployment of UAV and comparison of UAV communication services based on its operating frequency. We also present major collision avoidance approaches, and specifically discuss collision avoidance approaches that are suitable for indoor applications. We also present the Flying Ad-hoc Networks (FANET) network architecture, communication and routing protocols for each Open System Interconnection (OSI) communication layers.
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Sánchez, Paloma, Rafael Casado, and Aurelio Bermúdez. "Real-Time Collision-Free Navigation of Multiple UAVs Based on Bounding Boxes." Electronics 9, no. 10 (October 3, 2020): 1632. http://dx.doi.org/10.3390/electronics9101632.
Повний текст джерелаАнотація:
Predictably, future urban airspaces will be crowded with autonomous unmanned aerial vehicles (UAVs) offering different services to the population. One of the main challenges in this new scenario is the design of collision-free navigation algorithms to avoid conflicts between flying UAVs. The most appropriate collision avoidance strategies for this scenario are non-centralized ones that are dynamically executed (in real time). Existing collision avoidance methods usually entail a high computational cost. In this work, we present Bounding Box Collision Avoidance (BBCA) algorithm, a simplified velocity obstacle-based technique that achieves a balance between efficiency and cost. The performance of the proposal is analyzed in detail in different airspace configurations. Simulation results show that the method is able to avoid all the conflicts in two UAV scenarios and most of them in multi-UAV ones. At the same time, we have found that the penalty of using the BBCA collision avoidance technique on the flying time and the distance covered by the UAVs involved in the conflict is reasonably acceptable. Therefore, we consider that BBCA may be an excellent candidate for the design of collision-free navigation algorithms for UAVs.
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Rudan, Igor, Vlado Frančić, Marko Valčić, and Matthew Sumner. "EARLY DETECTION OF VESSEL COLLISION SITUATIONS IN A VESSEL TRAFFIC SERVICES AREA." Transport 35, no. 2 (November 18, 2019): 121–32. http://dx.doi.org/10.3846/transport.2019.11464.
Повний текст джерелаАнотація:
This study presents enhanced collision detection model in a Vessel Traffic Services (VTS) area. The proposed detection method of collision situations is based on the assumption that VTS station is provided with passage plans of all the vessels in a monitored area. By using an early detection model for prediction of possible collision situations, VTS stations could switch from the area-monitoring concept to the passage-monitoring system. An early detection model of collision risks in a VTS area uses vessels’ dynamic characteristics as inputs (vessels’ position, course over ground and speed), and delivers prediction of their future positions as output. In order to achieve the desired accuracy, the model takes into the account the intended course alterations and the impending environmental loads. The model is able to provide the outputs as early as the passage plans are submitted to a VTS monitored area. Hence, when discussing model’s capability for early detection of collision situations, improved VTS operating standards could be developed in order to achieve safer passages through enhanced collision avoidance strategies. Simulation results clearly show the advantages of the proposed model as a decision support tool for a VTS operator when combining passage plans with the analysis of environmental loads.
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Ribeiro, Bruno, Maria João Nicolau, and Alexandre Santos. "Using Machine Learning on V2X Communications Data for VRU Collision Prediction." Sensors 23, no. 3 (January 22, 2023): 1260. http://dx.doi.org/10.3390/s23031260.
Повний текст джерелаАнотація:
Intelligent Transportation Systems (ITSs) are systems that aim to provide innovative services for road users in order to improve traffic efficiency, mobility and safety. This aspect of safety is of utmost importance for Vulnerable Road Users (VRUs), as these users are typically more exposed to dangerous situations, and their vehicles also possess poorer safety mechanisms when in comparison to regular vehicles on the road. Implementing automatic safety solutions for VRU vehicles is challenging since they have high agility and it can be difficult to anticipate their behavior. However, if equipped with communication capabilities, the generated Vehicle-to-Anything (V2X) data can be leveraged by Machine Learning (ML) mechanisms in order to implement such automatic systems. This work proposes a VRU (motorcyclist) collision prediction system, utilizing stacked unidirectional Long Short-Term Memorys (LSTMs) on top of communication data that is generated using the VEINS simulation framework (coupling the Simulation of Urban MObility (SUMO) and Network Simulator 3 (ns-3) tools). The proposed system performed well in two different scenarios: in Scenario A, it predicted 96% of the collisions, averaging 4.53 s for Average Prediction Time (s) (APT) and with a Correct Decision Percentage (CDP) of 41% and 78 False Positives (FPs); in Scenario B, it predicted 95% of the collisions, with a 4.44 s APT, while the CDP was 43% with 68 FPs. The results show the effectiveness of the approach: using ML methods on V2X data allowed the prediction of most of the simulated accidents. Nonetheless, the presence of a relatively high number of FPs does not allow for the usage of automatic safety features (e.g., emergency breaking in the passenger vehicles); thus, collision avoidance must be achieved manually by the drivers.
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Życzkowski, Marcin, Joanna Szłapczyńska, and Rafał Szłapczyński. "Review of Weather Forecast Services for Ship Routing Purposes." Polish Maritime Research 26, no. 4 (December 1, 2019): 80–89. http://dx.doi.org/10.2478/pomr-2019-0069.
Повний текст джерелаАнотація:
Abstract Weather data is nowadays used in a variety of navigational and ocean engineering research problems: from the obvious ones like voyage planning and routing of sea-going vessels, through the analysis of stability-related phenomena, to detailed modelling of ships’ manoeuvrability for collision avoidance purposes. Apart from that, weather forecasts are essential for passenger cruises and fishing vessels that want to avoid the risk associated with severe hydro-meteorological conditions. Currently, there is a wide array of services that offer weather predictions. These services include the original sources – services that make use of their own infrastructure and research models – as well as those that further postprocess the data obtained from the original sources. The existing services also differ in their update frequency, area coverage, geographical resolution, natural phenomena taken into account and finally – output file formats. In the course of the ROUTING project, primarily addressing ship weather routing accounting for changeable weather conditions, the necessity arose to prepare a report on the state-of-the-art in numerical weather prediction (NWP) modelling. Based on the report, this paper offers a thorough review of the existing weather services and detailed information on how to access the data offered by these services. While this review has been done with transoceanic ship routing in mind, hopefully it will also be useful for a number of other applications, including the already mentioned collision avoidance solutions.