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Reversed design of selective infrared emitter based on the combination of equivalent medium theory and a-star algorithm

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OPTICS AND LASER TECHNOLOGY 2024年 176卷

作者： Guo, Hetao Yang, Xiaolong Zhu, Di Nanjing Univ Aeronaut & Astronaut Coll Mech & Elect Engn Nanjing 210016 Peoples R China Nanjing Univ Aeronaut & Astronaut Jiangsu Key Lab Precis & Micromfg Technol Nanjing 210016 Peoples R China

Metal-dielectric-metal (MDM) structure can selectively emit infrared wave because of the local plasma resonance;it has attracted intensive attentions in sensor, radiative cooling and many other fields. However, it remains challenging to efficiently design a customized near-ideal selective emitter. In this work, a concise design method that combined equivalent medium theory with a-star algorithm was developed for the reversed design of the MDM structure. This strategy for designing and optimizing the MDM structure, implemented the customization of the selective emitters. Meanwhile, design efficiency was improved by similar to 10 times. A variety of nearideal selective infrared emitters at 6 mu m were designed based on different materials. The essence of structural parameter or material change was to adjust the radiation damping and dissipative damping of the structure to regulate the spectral radiation characteristics, such as emissivity peak and full width at half maximum (FWHM). The Q-factor of the high-performance selective emitter depends on the higher loss tangent of metals. Both the computational method and the concluded results of this work would provide enlightenment for future design of MDM structures intended for many cutting-edge applications, such as infrared sensing and radiative cooling.

关键词： MDM structure Equivalent medium theory a-star algorithm Selective infrared emitter

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A self-adaptive neighborhood search a-star algorithm for mobile robots global path planning

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COMPUTERS & ELECTRICAL ENGINEERING 2024年 123卷

作者： Huang, Jiabo Chen, Chunmei Shen, Junjie Liu, Guihua Xu, Feng Southwest Univ Sci & Technol Sch Informat Engn Mianyang 621000 Peoples R China Southwest Univ Sci & Technol Robot Technol Used Special Environm Key Lab Sichua Mianyang 621000 Peoples R China

Aiming to address the issues of low search efficiency and unsmooth paths in traditional Astar algorithm for mobile robots global path planning, this paper proposes an improved a-star algorithm. Firstly, to tackle the inefficiency of 16-neighborhood search and the unsmooth paths of 8-neighborhood search, a new 5-neighborhood search method is introduced, which retains the path smoothness characteristics of 16-neighborhood search while achieving higher time efficiency. Secondly, an obstacle constraint approach using 4-neighborhood search is proposed to address the issues of crossing obstacles and getting trapped in dead ends encountered in 5neighborhood search. Furthermore, the improved algorithm employs second-order B & eacute;zier curve to smoothen paths with excessively large-angle corners. Simulations conducted on different scenarios and sizes of grid maps indicate that, compared to several classic variants of the Astar algorithm and recent improvements, the improved a-star algorithm not only generates the smoothest and shortest path, but is also more stable in improving time efficiency. By using a new 5-neighborhood and adaptively changing the neighborhood, the improved a-star algorithm addresses the shortcomings of existing improvements that cannot have both search efficiency and path smoothness.

关键词： a-star algorithm Neighborhood search Path planning Mobile robot

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Global Path Planning of Unmanned Surface Vehicle Based on Improved a-star algorithm

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SENSORS 2023年第14期23卷 6647页

作者： Zhang, Huixia Tao, Yadong Zhu, Wenliang Jiangsu Ocean Univ Sch Ocean Engn Lianyungang 222005 Peoples R China Jiangsu Ocean Univ Sch Mech Engn Lianyungang 222005 Peoples R China

To make unmanned surface vehicles that are better applied to the field of environmental monitoring in inland rivers, reservoirs, or coasts, we propose a global path-planning algorithm based on the improved a-star algorithm. The path search is carried out using the raster method for environment modeling and the 8-neighborhood search method: a bidirectional search strategy and an evaluation function improvement method are used to reduce the total number of traversing nodes;the planned path is smoothed to remove the inflection points and solve the path folding problem. The simulation results reveal that the improved a-star algorithm is more efficient in path planning, with fewer inflection points and traversing nodes, and the smoothed paths are more to meet the actual navigation demands of unmanned surface vehicles than the conventional a-star algorithm.

关键词： unmanned surface vehicle a-star algorithm bi-directional search path planning path smoothing

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Dynamic anti-collision a-star algorithm for multi-ship encounter situations

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APPLIED OCEAN RESEARCH 2022年 118卷 1页

作者： He, Zhibo Liu, Chenguang Chu, Xiumin Negenborn, Rudy R. Wu, Qing Wuhan Univ Technol Intelligent Transport Syst Res Ctr Wuhan Peoples R China Wuhan Univ Technol Sch Transportat & Logist Engn Wuhan Peoples R China Wuhan Univ Technol Natl Engn Res Ctr Water Transport Safety Wuhan Peoples R China Delft Univ Technol Dept Maritime & Transport Technol Delft Netherlands Wuhan Univ Technol Chongqing Res Inst Chongqing Peoples R China

For the complex multi-ship encounter scenarios, this article proposes a dynamic collision avoidance path planning algorithm based on the a-star algorithm and ship navigation rules, namely Dynamic Anti-collision A-star (DAA-star) algorithm. A dynamic search mechanism of the DAa-star algorithm considering time factors is designed to enable the collision avoidance for situations with known moving obstacles. A quaternion ship domain is generated based on Automatic Identification System (AIS) data, and the navigation risk cost is calculated with the combination of the quaternion ship domain and potential field. The searching constraints conforming with the Regulations for Preventing Collision at Sea (COLREGS) rules are set for the DAa-star algorithm to guarantee the safety of collision avoidance. Meanwhile, the individual ship maneuverability constraints and maneuverability differences from ship to ship are both considered in the proposed DAAstar algorithm, which can solve the path planning problem with dynamic obstacles in multi-ship encounter scenarios. The simulation results show that, compared with the traditional a-star algorithm and dynamic a-star algorithm, the DAa-star algorithm can generate more reasonable dynamic and static obstacle avoidance paths in complex navigation scenarios in the trade-off between the navigation risk and economical efficiency.

关键词： a-star algorithm Dynamic anti-collision COLREGS Ship domain Multi-ship encounter

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Research on Parking Path Planing Based on a-star algorithm

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Journal of New Media 2023年第1期5卷 55-64页

作者： Zhiliang Deng Dong Wang Nanjing University of Information Science&Technology Nanjing210044China

The issue of finding available parking spaces and mitigating conges-tion during parking is a persistent challenge for numerous car owners in urban *** this paper,we propose a novel method based on the a-star algorithm to calculate the optimal parking path to address this *** integrate a road impedance function into the conventional a-star algorithm to compute path duration and adopt a fusion function composed of path length and duration as the weight matrix for the a-star algorithm to achieve optimal path ***,we conduct simulations using parking lot modeling to validate the effectiveness of our approach,which can provide car drivers with a reliable optimal parking navigation route,reduce their parking costs,and enhance their parking experience.

关键词： a-star algorithm path planning intelligent transportation

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Robot path planning based on IAPF-a-star algorithm

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INTERNATIONAL JOURNAL OF MODELING SIMULATION AND SCIENTIFIC COMPUTING 2024年第6期15卷

作者： Wang, Yixuan Wang, Lei Li, Dongdong Cai, Jingcao Wang, Tiancheng Xia, Qiangqiang Anhui Polytech Univ Sch Mech Engn Wuhu 241000 Anhui Peoples R China Yangtze River Delta Hart Robot Ind Technol Res Ins Wuhu 241000 Anhui Peoples R China

The traditional a-star algorithm has the problem of performing much invalid traversal work of nodes near concave obstacles when dealing with path planning tasks in the presence of concave obstacles. To solve this problem, a fusion algorithm (called IAPF-A-star here) based on improved artificial potential field (IAPF) and A-star is proposed. In IAPF-A-star, to better measure the distances between the nodes and the target node, the potential energy of the artificial potential field is used to represent the node's proximity to the target node, and an iterative correction method is used to improve the potential field in order to eliminate the local low-potential energy that may exist in the artificial potential field. The improved potential field effectively avoids the occurrence of local low-potential fields and makes it possible to measure the position of nodes in relation to their target node by means of the potential field. Finally, the obtained path is converted to a curve path by using a cubic spline curve. In addition, to solve the problem that the curve path generated by the cubic spline curve may collide with obstacles, a path optimization strategy based on an adaptive cubic spline curve is proposed to make the final path smooth and collision avoidance, shorter and closer to the actual situation. Simulation experiments show that the proposed IAPF-a-star algorithm in this paper can effectively avoid the problem of additional local energy consumption caused by concave obstacles when processing path planning tasks, and the traversal of invalid nodes facing different complex concave obstacles is effectively avoided.

关键词： Mobile robot path planning a-star algorithm artificial potential field iterative correction adaptive cubic spline curve

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Robust Sheet Metal Bend Sequencing Method Based on a-star algorithm

Robust Sheet Metal Bend Sequencing Method Based on A-star Al...

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2011 IEEE International Conference on Computer Science and Automation Engineering(CSAE 2011)

作者： Zhang Lichao Huazhong University of Science & Technology State key Laboratory of Material Processing and Die and Mould Technology Wuhan,China Zhou Qiang Huazhong University of Science & Technology State key Laboratory of Material Processing and Die and Mould Technology Wuhan,China Zhang Yi Huazhong University of Science & Technology State key Laboratory of Material Processing and Die and Mould Technology Wuhan,China He Fafu Huazhong University of Science & Technology State key Laboratory of Material Processing and Die and Mould Technology Wuhan,China

the bending stage is the most critical part in manufacturing sheet metal ***,the automatic bend sequencing is a necessity for process planning.A robust method for sheet metal bend sequencing is presented in this paper,in which hard reject criteria and the preclusion method of complex bending model are both concerned.A set of solution methods in bend sequencing based on a-star algorithm is also developed ***,an application example of complex bending model is used to verify the presented bend sequencing *** a CNC bending machine process planning software is developed based on it.

关键词： Sheet metal Bend Sequencing a-star algorithm

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Solving Inverse Kinematics Problem of Robot Arm with Adjustable Snap-width a-star algorithm

Solving Inverse Kinematics Problem of Robot Arm with Adjusta...

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International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology

作者： Jirayus Chaichawananit Saiyan Saiyod Department of Computer Science Faculty of Science Khon Kaen University

ISBN: (纸本)9781467397506

Playing an important role in our everyday life, robot arms need the controlling systems for effectively moving each part in the desired movement, and their manipulation varies across their physical structures. To be precise, arms of the industrial robots used for welding consist of the sequence of jointed arms called kinematic chains and the arm tip called end effector. Such construction typically leads to problems about inverse kinematics in terms of its calculation for adjusting the angle size of each joint to have the end effector reach the desired target accurately and to minimize the movements in each joint. Therefore, this paper has presented a solution for those problems about inverse kinematics based on gradient following procedure and a-star algorithm in order to achieve the best practice. To suggest a solution, this paper has concerned about the accuracy and the minimum movement by carrying out a simulation on the simulative model with MATLAB program. According to the result, it was possible to calculate the proper degrees of the joint angles for creating the most accurate reach range of the end effector.

关键词： Inverse Kinematics a-star algorithm Robot Arm Snap-width

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LIFETIME ENHANCEMENT IN WIRELESS SENSOR NETWORKS USING FUZZY APPROACH AND a-star algorithm

LIFETIME ENHANCEMENT IN WIRELESS SENSOR NETWORKS USING FUZZY...

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IET Conference on Wireless Sensor Systems

作者： I. S. AlShawi L. Yan W. Pan B. Luo School of Information Science & Technology Southwest Jiaotong University

ISBN: (纸本)9781622762835

Wireless Sensor Networks (WSNs) are used in many applications to gather sensitive information which is then forwarded to an analysis centre. Resource limitations have to be taken into account when designing a WSN infrastructure. Unbalanced energy consumption is an inherent problem in WSNs characterized by multi-hop routing and many-to-one traffic pattern. This uneven energy dissipation can significantly reduce network lifetime. This paper proposes a new routing method for WSNs to extend the network lifetime using a combination of Fuzzy approach and a-star algorithm. The proposal is to determine the optimal routing path from the source to the destination by favouring the highest remaining battery power, minimum number of hops, as well as minimum traffic loads. To demonstrate the effectiveness of the proposed method in terms of balancing energy consumption and maximization of network lifetime, we compare our approach with A-star search algorithm and Fuzzy approach using the same routing criteria. Simulation results demonstrate that the network lifetime is significantly increased by employing the proposed routing method.

关键词： a-star algorithm Fuzzy Logic Network Lifetime Routing Wireless Sensor Networks

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A-star Based algorithm Applied to Target Search and Rescue by a UAV Swarm 19

A-Star Based Algorithm Applied to Target Search and Rescue b...

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Latin American Robotics Symposium (LARS) / Brazilian Symposium on Robotics (SBR) / Workshop on Robotics in Education (WRE)

作者： Bernardo, Guilherme T. T. Vogas, Luan M. B. Rodrigues, Sargon D. S. Lopes, Thiago G. G. Marcondes, Cesar A. C. Loubach, Denis S. Sbruzzi, Elton F. Verri, Filipe A. N. Marques, Johnny C. Pereira, Lourenco A., Jr. Maximo, Marcos R. O. A. Curtis, Vitor V. Aeronaut Inst Technol Elect & Comp Engn Div Sao Jose Dos Campos SP Brazil

ISBN: (纸本)9781665462808

Drone swarms are being utilized in several areas, e.g., monitoring, surveillance, security, and search, demonstrating great potential. In this paper, we considered a specific number of drones flying simultaneously (using computational intelligence techniques between them to avoid collisions) and increased the effectiveness in conducting search tasks. The main contribution of this work is to propose a technique to coordinate the swarm using search methods based on the A* algorithm and its heuristics (i.e., Euclidean and Manhattan distances). The communication between drones is also evaluated and applied to a target search problem on a two-dimensional cost map. The results show a considerable optimization in the effectiveness of the drone swarm (fewer drones are blocked at local minima), which highlights the contribution of this work.

关键词： UAV Swarm a-star algorithm Target Search Potential Fields Swarm Intelligence Collective Intelligence

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