检索结果-内蒙古大学图书馆

Optimal Multi-Robot Path Planning for Cyclic Tasks using Petri Nets

IFAC-PapersOnLine 2022年第28期55卷 9-15页

作者： Peng Lv Guangqing Luo Xiang Yin Ziyue Ma Shaoyuan Li Department of Automation and Key Laboratory of System Control and Information Processing Shanghai Jiao Tong University Shanghai 200240 China School of Electro-Mechanical Engineering Xidian University Xi'an 710071 China

In this paper, we investigate the problem of optimal multi-robot path planning for a cyclic task represented by a particular type of linear-temporal logic (LTL) formulae. Specifically, the team of robot needs to fulfill a given LTL formula and at the same time, accomplishes some particular tasks infinitely often. To avoid the state-space explosion when the number of robot increases, we use Petri nets to model the team of multi-robot. Our goal is to find an optimal infinite sequence in the prefix-suffix form for each robot such that the average cost per task is minimized. We propose an efficient planning method based on the notion of basis reachability graph (BRG), which is a compact representation of the reachability space of the PN. We demonstrate the computational efficiency of our method through illustrative examples.

关键词： Petri Nets Linear Temporal Logic Multi-Robot systems Task Planning

来源：评论

学校读者我要写书评

暂无评论

Early Forest Fire Recognition Method Based on C-GhostNet Network 5

Early Forest Fire Recognition Method Based on C-GhostNet Net...

引用

5th International Symposium on Autonomous systems, ISAS 2022

作者： Li, Mengna Zhang, Youmin Mu, Lingxia Xin, Jing Yu, Ziquan Jiao, Shangbin Liu, Han Xie, Guo Yi, Yingmin Xi'an University of Technology Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Shaanxi Xi'an710048 China Concordia University Industrial and Aerospace Engineering Department of Mechanical MontrealQCH3G 1M8 Canada Nanjing University of Aeronautics and Astronautics College of Automation Engineering Nanjing211106 China Xi'an University of Technology Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an Shaanxi 710048 China

ISBN: (纸本)9781665487085

Early forest fire image recognition plays an important role in timely fire fighting. This paper proposes an early forest fire recognition method based on C-GhostNet network. The C-GhostNet network is an improved version of GhostNet, which mainly consists of a series of c-ghost bottlenecks, each c-ghost bottleneck mainly consists of two c-ghost modules. Through the concat operation and channel shuffle, the c-ghost module establishes the relationship between the input data and the output features generated by the original ghost module, so that GhostNet network has the ability to capture contextual features. The experimental results show that the C-GhostNet network achieves better recognition performance than GhostNet without introducing additional computational load, and the running speed reaches about 20FPS, which basically realizes real-time recognition. In addition, like GhostN et, the C-GhostNet network is also a lightweight network. © 2022 IEEE.

关键词： Image recognition

来源：评论

学校读者我要写书评

暂无评论

Vibrations Characteristics Analysis of Metal Composite 17-4ph Material Extrusion Additively Manufactured Parts Under Amplitude Dependence Property

SSRN

引用

SSRN 2023年

作者： Siyajeu, Yannick Xu, Zhuo Jiang, Shijie Li, Hui Wen, Bangchun Li, He School of Mechanical Engineering and Automation Northeastern University Shenyang110819 China Key laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Northeastern University Shenyang110819 China School of Mechanical Engineering Northeast Electric Power University Jilin132014 China

In this study, a dynamic linear model of a metal composite filament ultra-fuse 17-4 PH stainless-steel material extrusion (ME) parts has been established considering the amplitude dependence. Material extrusion plates have been built in x and z-direction. Based on the Jones-Nelson model an investigation of the natural frequency and response and damping ratio of ultra-fuse 17-4PH metal composite material extrusion specimens has been completed. Equations of the proposed dynamic model have been solved by the combination of the orthogonal polynomial method and energy method. The Newton-Raphson iteration has been employed to predict the natural frequencies and responses of the ultra-fuse 17-4 PH stainless-steel material extrusion manufactured parts. The results indicate that the predicted damping characteristics of the ultra-fuse 17-4 PH metal composite material extrusion parts have a good consistency with the experimental ones, meanwhile, when amplitude vibration increases from [0.25g…2.00g], the response of the ultra-fuse 17-4 PH metal composite material extrusion parts increase as well both for x and z-direction samples. © 2023, The Authors. All rights reserved.

关键词： Iterative methods

来源：评论

学校读者我要写书评

暂无评论

Multi-Scale Eca Attention Network: A Rotation mechanical Domain Adaptation Method with Minimal Class Confusion

SSRN

引用

SSRN 2023年

作者： Li, Xueyi Yu, Tianyu Wang, Xiangkai Li, Daiyou Xie, Zhijie Kong, Xiangwei College of Mechanical and Electrical Engineering Northeast Forestry University Harbin150040 China Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Northeastern University Shenyang110819 China School of Mechanical Engineering and Automation Northeastern University Shenyang110819 China

Unsupervised rotation mechanical fault diagnosis methods have become popular, but existing unsupervised methods still have some issues. For example, it is challenging to capture vibration signal features at different scales and to address partial class confusion. To improve the diagnostic performance, this study introduces a multi-scale, Efficient Channel Attention (ECA) attention mechanism, Joint Adaptation Network (JAN), and Minimum Class Confusion (MCC) for addressing the aforementioned issues. Firstly, the authors design a multi-scale fault feature extraction module to capture discriminative information at different scales in vibration signals. Secondly, the authors introduce the ECA attention mechanism to weight the extracted features at the channel level, enhancing useful features and suppressing redundant features. Then, the authors employ the JAN method to establish local maximum mean discrepancy, enabling adaptation between corresponding sub-domains of the source and target domains, avoiding the problem of being too close. Finally, the authors use MCC as the loss function to reduce prediction confusion between correct and ambiguous categories in target samples, thus improving transfer performance. Experimental results demonstrate that the proposed method exhibits excellent performance in unsupervised rotation mechanical fault diagnosis tasks. © 2023, The Authors. All rights reserved.

关键词： Fault detection

来源：评论

学校读者我要写书评

暂无评论

Stress analysis of escalator truss structure based on sub-model method 26

Stress analysis of escalator truss structure based on sub-mo...

引用

26th ISSAT International Conference on Reliability and Quality in Design, RQD 2021

作者： Qian, Wenxue Yin, Xiaowei Song, Shuai He, Xuehong School of Mechanical Engineering and Automation Northeastern University Shenyang110819 China Shenyang Institute of Engineering School of Mechanical Shenyang110136 China Key Laboratory of Vibration and Control of Aero-Propulsion System of Ministry of Education Northeastern University Shenyang110819 China

ISBN: (纸本)9780991057696

The 3D solid model of the escalator truss system was established and imported into the finite element analysis software for detailed analysis, compared and analyzed the effect of the presence or absence of bolts on the stress of the escalator truss structure. The strength and stiffness of the escalator truss structure was calibrated according to the relevant standards. In order to get more accurate results of the stresses at the bolted connections, finite element analysis of the bolted connections was refined using the sub-model method, based on the overall analysis results, a local refinement model was established. The results show that the sub-model approach gives more accurate results. The results show that the strength and stiffness of the escalator truss structure meet the required standard. © 2021 Proceedings - 26th ISSAT International Conference on Reliability and Quality in Design, RQD 2021. All rights reserved.

关键词： Finite element method

来源：评论

学校读者我要写书评

暂无评论

Dynamic characteristics of a shrouded blade with impact and friction

引用

Frontiers of mechanical engineering 2020年第2期15卷 209-226页

作者： Xumin GUO Jin ZENG Hui MA Chenguang ZHAO Lin QU Bangchun WEN School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Northeastern UniversityShenyang 110819China

A simplified computational model of a twisted shrouded blade with impact and friction is *** this model,the shrouded blade is simulated by a flexible Timoshenko beam with a tip-mass,and the effects of centrifugal stiffening,spin softening,and Coriolis force are *** force is simulated using a linear spring model,and friction force is generated by a tangential spring model under sticking state and a Coulomb friction model under sliding *** proposed model is validated by a finite element ***,the effects of initial gap and normal preload,coefficient of friction,and contact stiffness ratio(the ratio of tangential contact stiffness to normal contact stiffness)on system vibration responses are *** show that resonant peaks become inconspicuous and impact plays a dominant role when initial gaps are large between adjacent *** contrast,in small initial gaps or initial normal preloads condition,resonant speed increases sharply,and the optimal initial normal preloads that can minimize resonant amplitude becomes *** of friction affects the optimal initial normal preload,but it does not affect vibration responses when the contact between shrouds is under full *** resonant amplitude decreases with the increase of contact stiffness ratio,but the optimal initial normal preload is unaffected.

关键词： twisted shrouded blade dynamic analysis impact friction separate-stick-slip motion

来源：评论

学校读者我要写书评

暂无评论

Computation and investigation of mode characteristics in nonlinear system with tuned/mistuned contact interface

引用

Frontiers of mechanical engineering 2020年第1期15卷 133-150页

作者： Houxin SHE Chaofeng LI Qiansheng TANG Hui MA Bangchun WEN School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion System(Ministry of Education) Northeastern UniversityShenyang 110819China

This study derived a novel computation algorithm for a mechanical system with multiple friction contact interfaces that is well-suited to the investigation of nonlinear mode characteristic of a coupling *** procedure uses the incremental harmonic balance method to obtain the nonlinear parameters of the contact ***,the computed nonlinear parameters are applied to rebuild the matrices of the coupling system,which can be easily solved to calculate the nonlinear mode characteristics by standard iterative ***,the derived method is applied to a cycle symmetry system,which represents a shaft–disk–blade system subjected to dry ***,this study analyzed the effects of the tuned and mistuned contact features on the nonlinear mode *** results prove that the proposed method is particularly suitable for the study of nonlinear characteristics in such nonlinear systems.

关键词： coupling vibration nonlinear mode original algorithm contact interface

来源：评论

学校读者我要写书评

暂无评论

Dynamic modeling and coupling characteristics of rotating inclined beams with twisted-shape sections

引用

Frontiers of mechanical engineering 2020年第3期15卷 374-389页

作者： Jin ZENG Chenguang ZHAO Hui MA Bangchun WEN School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Northeastern UniversityShenyang 110819China

In the existing literature, most studies investigated the free vibrations of a rotating pre-twisted cantilever beam;however, few considered the effect of the elastic-support boundary and the quantification of modal coupling degree among different vibration directions. In addition, Coriolis, spin softening, and centrifugal stiffening effects are not fully included in the derived equations of motion of a rotating beam in most literature, especially the centrifugal stiffening effect in torsional direction. Considering these deficiencies, this study established a coupled flapwise–chordwise–axial–torsional dynamic model of a rotating double-tapered, pre-twisted, and inclined Timoshenko beam with elastic supports based on the semi-analytic method. Then, the proposed model was verified with experiments and ANSYS models using Beam188 and Shell181 elements. Finally, the effects of setting and pre-twisted angles on the degree of coupling among flapwise, chordwise, and torsional directions were quantified via modal strain energy ratios. Results showed that 1) the appearance of torsional vibration originates from the combined effect of flapwise–torsional and chordwise–torsional couplings dependent on the Coriolis effect, and that 2) the flapwise–chordwise coupling caused by the pure pre-twisted angle is stronger than that caused by the pure setting angle.

关键词： elastic-support boundary pre-twisted beam semi-analytic method modal strain energy ratio torsional vibration

来源：评论

学校读者我要写书评

暂无评论

Nonlinear control of Crane systems Based on Intelligence Computing of Disturbance Observer Under Mismatched Disturbance

Nonlinear Control of Crane Systems Based on Intelligence Com...

引用

International Symposium on Parallel and Distributed Processing with Applications, ISPA

作者： Tianlei Wang Yiyan Wang Meng Xu Jiajie Tian Jingling Zhang Zhiyong Hong School of Electronic and Information Engineering Wuyi University Jiangmen China Jiangmen Key Laboratory of Kejie Semiconductor Bonding Technology and Control System Jiangmen China School of Mechanical and Automation Engineering Wuyi University Jiangmen China Guangdong Kejie Technology Co. Ltd Jiangmen China

ISBN: (数字)9798331509712

ISBN: (纸本)9798331509729

A control method based on disturbance observer is proposed to address the positioning drift issue of the gantry crane under unmatched disturbances, aiming at precise positioning of the trolley and effective payload swing angle attenuation in a variable-length two-dimensional lifting system. The control scheme comprises a combination of a proportional-derivative controller and a disturbance observer. Firstly, the design of the coupling function in this paper is based on the observation of the natural characteristics of the dynamical model. It cleverly designs the coupling function, which not only helps to effectively reduce the swing angle but also prevents the problem of positioning drift under non-matching disturbances, subsequently, design a controller by integrating intelligent computing with control theory. Secondly, the designed disturbance observer observes and compensates for the system output to achieve disturbance suppression. Thirdly, a thorough stability analysis has been conducted to demonstrate that the proposed controller satisfies the desired conditions. Finally, simulation results illustrate that the pro-posed method success-fully addresses the limitations of existing methods and exhibits superior performance and robustness.

关键词： Couplings Cranes Computational modeling Simulation Attenuation Disturbance observers Stability analysis Robustness Mathematical models Payloads

来源：评论

学校读者我要写书评

暂无评论

Sensor-based Multi-agent Coverage control with Spatial Separation in Unstructured Environments

arXiv

引用

arXiv 2024年

作者： Wang, Xinyi Xu, Jiwen Gao, Chuanxiang Chen, Yizhou Zhang, Jihan Wang, Chenggang Ding, Yulong Chen, Ben M. Department of Mechanical and Automation Engineering The Chinese University of Hong Kong N.T. Shatin Hong Kong Department of Automation Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai Jiao Tong University Shanghai200240 China Department of Control Science and Engineering Tongji University Shanghai China Frontiers Science Center for Intelligent Autonomous Systems Ministry of Education China

Multi-robot systems have increasingly become instrumental in tackling coverage problems. However, the challenge of optimizing task efficiency without compromising task success still persists, particularly in expansive, unstructured scenarios with dense obstacles. This paper presents an innovative, decentralized Voronoi-based coverage control approach to reactively navigate these complexities while guaranteeing safety. This approach leverages the active sensing capabilities of multi-robot systems to supplement GIS (Geographic Information system), offering a more comprehensive and real-time understanding of environments like post-disaster. Based on point cloud data, which is inherently non-convex and unstructured, this method efficiently generates collision-free Voronoi regions using only local sensing information through spatial decomposition and spherical mirroring techniques. Then, deadlock-aware guided map integrated with a gradient-optimized, centroid Voronoi-based coverage control policy, is constructed to improve efficiency by avoiding exhaustive searches and local sensing pitfalls. The effectiveness of our algorithm has been validated through extensive numerical simulations in high-fidelity environments, demonstrating significant improvements in task success rate, coverage ratio, and task execution time compared with others. Copyright © 2024, The Authors. All rights reserved.

关键词： Multipurpose robots

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：