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Kinematics modeling and trajectory planning for the skull reconstruction robot

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Kinematics modeling and trajectory planning for the skull re...

2021 IEEE International Conference on Real-Time Computing and Robotics, RCAR 2021

作者： Wang, Weiqun Wang, Xiru Hou, Zeng-Guang Fang, Zhijie Jiao, Yuze Luo, Yangyu Gong, Jian State Key Laboratory for Management and Control of Complex Systems Beijing100190 China Beijing100080 China Center for Excellent in Brain Science and Intelligence Technology Beijing100190 China Department of Electronics Polytech Nice Sophia Nice06200 France CASIA UCAS Department of Pediatric Neurosurgery Beijing Tiantan Hospital Capital Medical University Beijing100050 China

ISBN: (纸本)9781665436786

A skull reconstruction robot has been developed to effectively overcome shortcomings of the traditional skull surgery and improve its efficiency and quality. In this study, kinematics modeling and trajectory planning for the robot are carried out. Firstly, the kinematic model of the robot is established based on the D-H method. The positioning points, which are used to determine the cutting plane, are given on the surface of the skull by the surgeon. The contour data for cutting can be obtained using a two dimensional laser scanning sensor, by adjusting the scanning light curtain to coincide with the cutting plane. Then, to ensure that the tools fixed at the robot end can always be perpendicular to the skull surface during the cutting or drawing process, the principal component analysis is introduced to design the normal vectors at the selected key points of the point cloud data for the skull surface. Moreover, the quintic polynomial interpolation method is used to construct the curves between the adjacent key points to make up for the defects of the skull surface and ensure the smoothness of the trajectory. Finally, workspace analysis based on Monte Carlo method is implemented, and the proposed kinematics modeling and trajectory planning methods are validated by simulation. © 2021 IEEE.

关键词： Monte Carlo methods

State Estimation for Linear systems with Quadratic Outputs

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arXiv

arXiv 2023年

作者： Berkane, Soulaimane Theodosis, Dionysis Hamel, Tarek Dimarogonas, Dimos V. Département d’informatique et d’ingénierie Université du Québec en Outaouis GatineauQC Canada theDepartment of Electrical Engineering Lakehead University ON Canada the Dynamic Systems and Simulation Laboratory Technical University of Crete Greece the Divi-sion of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Sweden I3S-CNRS University Côte d’Azur Institut universitaire de France France

This letter deals with the problem of state estimation for a class of systems involving linear dynamics with multiple quadratic output measurements. We propose a systematic approach to immerse the original system into a linear time-varying (LTV) system of a higher dimension. The methodology extends the original system by incorporating a minimum number of auxiliary states, ensuring that the resulting extended system exhibits both linear dynamics and linear output. Consequently, any Kalman-type observer can showcase global state estimation, provided the system is uniformly observable. © 2023, CC BY.

关键词： Time varying systems

simulation and Experimental Study on Cold Spraying W-Cu Composite Coating with High Retainability of W by Core-Shell Powder

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SSRN 2022年

作者： Deng, Nan Qu, Dandan Zhang, Kun Liu, Guoliang Li, Shaofu Zhou, Zhangjian School of Materials Science and Engineering Xi’an University of Technology Xi’an710048 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing100083 China Wide Range Flight Engineering Science and Application Center Institute of Mechanics Chinese Academy of Sciences Beijing100190 China School of Engineering Science University of Chinese Academy of Sciences Beijing100049 China State key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy Science Beijing100190 China

This study successfully fabricated a W-Cu composite coating with high W retention by cold spray using a novel core-shell powder. Finite element simulation was used to investigate the impact and deposition mechanics during cold spraying of core-shell compared to traditional satellite powder. The results showed that the core-shell powder exhibits non-local strain and dispersed residual stress in the final coating, enabling the successful preparation of the cold-sprayed W-Cu composite coating with high W content, and the final coating displays a non-pancake-like layer morphology. The final coating showed super-high W retention (98.3%) and reduced bulk porosity (1%) after optimized core-shell powder by adding a transition layer of Ni and appropriate heat treatment. © 2022, The Authors. All rights reserved.

关键词： Composite coatings

Non-Equilibrium Time-Relaxation Kinetic Model for Compressible Turbulence Modeling

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SSRN 2022年

作者： Cao, Guiyu Pan, Liang Xu, Kun Wan, Minping Chen, Shiyi Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology Guangdong Shenzhen518055 China Department of Mathematics Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong Laboratory of Mathematics and Complex Systems School of Mathematical Sciences Beijing Normal University Beijing100875 China Shenzhen Research Institute Hong Kong University of Science and Technology Guangdong Shenzhen518057 China Department of Mechanics and Aerospace Engineering Southern University of Science and Technology Guangdong Shenzhen518055 China Guangdong-Hong Kong-Macao Joint Laboratory for Data-Driven Fluid Mechanics and Engineering Applications Southern University of Science and Technology Guangdong Shenzhen518055 China

For the first time, the non-equilibrium time-relaxation kinetic model (NTRKM) is proposed for compressible turbulence modeling on unresolved grids. Within the non-equilibrium time-relaxation framework, NTRKM is extended in the form of modified Bhatnagar-Gross-Krook model. Based on the first-order Chapman-Enskog expansion, NTRKM connects with the six-variable macroscopic governing equations. The first five governing equations correspond to the conservative laws in mass, momentum and total energy, while the sixth equation governs the evolution of unresolved turbulence kinetic energy Kutke. The unknowns in NTRKM, including turbulent relaxation time and source term, are determined by essential gradient-type assumption and standard dynamic modeling approach. Current generalized kinetic model on unresolved grids consequently offers a profound mesoscopic understanding for one-equation subgrid-scale turbulence kinetic energy Ksgs model in compressible large eddy simulation. To solve NTRKM accurately and robustly, a non-equilibrium gas-kinetic scheme is developed, which succeeds the well-established gas-kinetic scheme for simulating Navier-Stokes equations. Three-dimensional decaying compressible isotropic turbulence and temporal compressible plane mixing layer on unresolved grids are simulated to evaluate the generalized kinetic model and non-equilibrium gas-kinetic scheme. The performance of key turbulent quantities up to second-order statistics confirms that NTRKM is comparable with the widely-used eddy-viscosity Smagorinsky model (SM) and dynamic Smagorinsky model (DSM). Specifically, compared with the DNS solution in temporal compressible plane mixing layer, the performance of NTRKM is much closer with DSM and better than SM. This study provides a workable approach for compressible turbulence modeling on unresolved grids, enriching the understanding of turbulence modeling within the non-equilibrium time-relaxation framework. © 2022, The Authors. All rights reserved.

关键词： Navier Stokes equations

Vertical Transport of Ultrafine Particles and Turbulence Evolution Impact on New Particle Formation at the Surface & Canton Tower

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SSRN 2023年

作者： Wu, Hao Li, Zhanqing Hai, Shangfei Gao, Yang Jiang, Jingkun Zhao, Bin Cribb, Maureen Zhang, Dongmei Pu, Dongyang Liu, Mengqi Wang, Chunling Lan, Jing Wang, Yuying Key Laboratory of China Meteorological Administration Atmospheric Sounding School of Electrical Engineering Chengdu University of Information Technology Chengdu610225 China Department of Atmospheric and Oceanic Science University of Maryland College ParkMD20742 United States College of Oceanic and Atmospheric Sciences Ocean University of China Qingdao266100 China Frontiers Science Center for Deep Ocean Multispheres and Earth System Key Laboratory of Marine Environmental Science and Ecology Ministry of Education Ocean University of China Qingdao266100 China School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control Tsinghua University Beijing100084 China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing100084 China College of Global Change and Earth System Science Beijing Normal University Beijing100875 China Guangzhou Climate and Agrometeorology Center Guangzhou511430 China Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science & Technology Nanjing210044 China

New particle formation (NPF) is a key process occurring in the planetary boundary layer (PBL). Newly formed particles are an important source of aerosols and cloud condensation nuclei (CCN) that influence clouds and climate, while the distribution of these new particles at different altitudes has rarely been studied. In-situ measurements of ultrafine particles (UFP) observed at the ground and at the top of the Canton Tower (454 m) located in downtown Guangzhou in southern China were analyzed using the measurements of multiple meteorological and physicochemical quantities, as both observed during a field campaign and simulated with the WRF-chem model. We found that turbulence and NPF characters vary considerably with heights, with UFP concentration diminishing by half from the surface to the tower top. This indicates the UFP transports upward from the ground in the lower boundary layer. A consistent relationship is established between the occurrences of NPF and the evolution of turbulence. The correlation between the exchange ratio at the tower top has correlated well with nucleation growth, suggesting that turbulence can play an important role in the episodes of NPF growth, whose growth rate is closely related to the turbulence exchange ratio, effectively dictating the ultrafine particle concentration before and during the lockdown period. A new mechanism is thus hypothesized: NPF happens eailer near the surface and grows faster at the upper PBL, attributed to condensable vapors being transported by turbulent vertical mixing in the boundary layer. Model simulations using the WRF-Chem model reveal that the exchange ratio changed the NPF parameters, supporting the proposed mechanism that the evolution of the PBL variation has a significant impact on NPF, which should not be omitted in the NPF research, since this physical factor could be a dominant one in the NPF mechanism. © 2023, The Authors. All rights reserved.

关键词： Turbulence

An Intelligent Maritime Scene Frame Prediction Based on Digital Twins technology

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An Intelligent Maritime Scene Frame Prediction Based on Digi...

Digital Twins and Parallel Intelligence (DTPI), IEEE International Conference on

作者： Zhong-Zheng Guo Kai Wang Jiang-Yi Qin Xian-Bin Li De-Chao Ran Yu Shen Unmanned Systems Research Center National Innovation Institute of Defense Technology Academy of Military Science Beijing China The State Key Laboratory for Management and Control of Complex Systems Institute of Automation Chinese Academy of Sciences Beijing China

This paper proposes a scene frame prediction system based on digital twin technology. The system is mainly composed of an unmanned perception module, a communication link module, a command center module that provides intelligent computing services, and an interaction and visualization module for human operators. These modules together constitute a system for predicting and recovery the time-series matrix composed of scene frames and object frames. At the same time, in view of the current problems of lack of real-time information and long response time in the maritime search and rescue (SAR) field, this paper instantiates the above system to improve the existing SAR system. Satellites and unmanned vehicles perceive part of the scene data of the real cyber-physical system in real-time and divide them into multiple frames according to the timestamps. In addition, this paper also proposes an environmental graph-attention network (Env-GAT) to achieve efficient and reliable frame predicting. Finally, this paper verifies that the performance of the spatiotemporal attention graph network model has reached the optimal level through computational experiments.

关键词： Satellites Digital twin Conferences Unmanned vehicles Search problems Real-time systems Trajectory

Multi-task Safe Reinforcement Learning for Navigating Intersections in Dense Traffic

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arXiv

arXiv 2022年

作者： Liu, Yuqi Gao, Yinfeng Zhang, Qichao Ding, Dawei Zhao, Dongbin The State Key Laboratory of Management and Control for Complex Systems Institute of Automation Chinese Academy of Sciences Beijing100190 China College of Artificial Intelligence University of Chinese Academy of Sciences Beijing100049 China School of Automation and Electrical Engineering University of Science and Technology Beijing Beijing1000839 China

Multi-task intersection navigation including the unprotected turning left, turning right, and going straight in dense traffic is still a challenging task for autonomous driving. For the human driver, the negotiation skill with other interactive vehicles is the key to guarantee safety and efficiency. However, it is hard to balance the safety and efficiency of the autonomous vehicle for multi-task intersection navigation. In this paper, we formulate a multi-task safe reinforcement learning with social attention to improve the safety and efficiency when interacting with other traffic participants. Specifically, the social attention module is used to focus on the states of negotiation vehicles. In addition, a safety layer is added to the multi-task reinforcement learning framework to guarantee safe negotiation. We compare the experiments in the simulator SUMO with abundant traffic flows and CARLA with high-fidelity vehicle models, which both show that the proposed algorithm can improve safety with consistent traffic efficiency for multi-task intersection navigation. Copyright © 2022, The Authors. All rights reserved.

关键词： Autonomous vehicles

Asynchronoush∞Control for It2 Fuzzy Networked System Subject to Hybrid Attacks Via Improved Event-Triggered Scheme

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SSRN 2023年

作者： Ali, M. Syed Tajudeen, M. Mubeen Perumal, R. Rajchakit, Grienggrai Sanober, Sumaya Cao, Jinde Complex Systems and Networked Science Research Laboratory Department of Mathematics Thiruvalluvar University Tamil Nadu Vellore632115 India Department of Mathematics SRM Institute of Technology Kattankulathur Chennai India Department of Mathematics Faculty of Science Maejo University Sansai Ching Mai50290 Thailand Department of Computer Science College of Arts and Science Prince Sattam Bin Abdul Aziz University Wadi Addwassir11991 Saudi Arabia School of Mathematics Southeast University Nanjing210096 China Yonsei Frontier Lab Yonsei University Seoul03722 Korea Republic of

This investigation focuses on the asynchronous H∞ control of interval type-2 (IT2) fuzzy networked systems under hybrid attacks employing a novel improved event-triggered scheme. An IT2 fuzzy model is proposed to represent the nonlinear system with external disturbances and parametric uncertainties. A new hybrid attack involving two popular attacks-denial-of-service (DoS) attack and deception attack is taken into account simultaneously in communication networks. In order to satisfy the Bernoulli distribution, hybrid attack developed as a stochastic random variable. To improve communication, a novel event-triggered scheme is used, which significantly reduces the amount of network data transmission and protects communication resources in the presence of hybrid attacks. In addition, sufficient conditions derived to ensure that the closed-loop system achieves the specified H∞ performance using the Lyapunov stability theory and linear matrix inequality technique. To demonstrate the proposed control technique, an application example of the mass-spring-damper mechanical system is presented. © 2023, The Authors. All rights reserved.

关键词： Denial-of-service attack

A digital microfluidic single-cell manipulation systemoptimized by extending-depth-of-field device

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Journal of Innovative Optical Health sciences 2023年第3期16卷 43-55页

作者： Qiushu Chen Qi Meng Yuzhe Liu Xiangan Long Yawei Kong Longfang Yao Liwen Chen Chuanyong Wu Kaiqin Chu Lan Mi Jiong Ma Department of Optical Science and Engineering Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing Key Laboratory of Micro and Nano Photonic Structures(Ministry of Education)School of Information Science and Technology Fudan University Shanghai 200433P.R.China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China Hefei 230027 AnhuiP.R.China Institute of Biomedical Engineering and Technology Academy for Engineering and Technology Fudan University Shanghai 200433P.R.China Institute of Photonic Chips Centre for Articial-Intelligence Nanophotonics School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai 200093 P.R.China Ruidge Biotech Co.Ltd. No.888Huanhu West 2nd Road Lin-Gang Special AreaChina(Shanghai)Pilot Free Trade Zone Shanghai 200131P.R.China Shanghai Hengxin BioTechnology Ltd.1688 North Guo Quan RdBldg A8Rm 801 Shanghai 200438P.R.China Centre for Articial-Intelligence Nanophotonics School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai 200093 P.R.China Shanghai Engineering Research Center of Industrial Microorganisms The Multiscale Research Institute of Complex Systems(MRICS)School of Life SciencesFudan UniversityShanghai 200433P.R.China

Microfuidic systems have been widely utilized in high-throughput biology analysis,but thedificulties in iquid manipulation and cell cultivation limit its *** work has developed a new digital microfluidic(DMF)system for on-demand droplet *** adopting anextending-depth-of-field(EDoF)phase modulator to the optical system,the entire depth of themicrofluidic channel can be covered in one image without any refocusing process,ensuring that 95%of the particles in the droplet are captured within three shots together with shaking *** this system,suspension droplets are generated and droplets containing only oneyeast cll can be recognized,then each single cell is cultured in the array of the *** growth in cell numbers and the green fluorescence protein(GFP)production via fluorescence imaging,the single cell with the highest production can be *** results haveproved the heterogeneity of yeast cells,and showed that the combined system can be applied forrapid single-cell sorting,cultivation,and analysis.

关键词： Single-cell analysis digital microfluidic(DMF) extending-depth-of-field system